InterPro (http://www.ebi.ac.uk/interpro/) is a database that integrates diverse information about protein families, domains and functional sites, and makes it freely available to the public via Web-based interfaces and services. Central to the database are diagnostic models, known as signatures, against which protein sequences can be searched to determine their potential function. InterPro has utility in the large-scale analysis of whole genomes and meta-genomes, as well as in characterizing individual protein sequences. Herein we give an overview of new developments in the database and its associated software since 2009, including updates to database content, curation processes and Web and programmatic interfaces.

VL - 40 CP - Database issue M3 - 10.1093/nar/gkr948 ER - TY - JOUR T1 -10.1128/IAI.74.3.1537-1546.2006

ER - TY - CONF T1 - Multiple range query optimization with distributed cache indexing T2 - Proceedings of the 2006 ACM/IEEE conference on Supercomputing Y1 - 2006 A1 - Nam,B. A1 - Andrade,H. A1 - Sussman, Alan JA - Proceedings of the 2006 ACM/IEEE conference on Supercomputing ER - TY - JOUR T1 - Multi-view Reconstruction of Static and Dynamic Scenes JF - Handbook of Mathematical Models in Computer Vision Y1 - 2006 A1 - Agrawal,M. A1 - Mittal,A. A1 - Davis, Larry S. AB - We explore the reconstruction of a three-dimensional scene from multiple images captured from far away viewpoints (wide-baseline camera arrangement). Such an arrangement is required for complex scenes where the visibility flora any one viewpoint is not sufficient to adequately reconstruct the entire scene. Also, such an arrangement reduces the error in triangulation of the features, thereby improving the accuracy of reconstruction. Our emphasis is on algorithms that recover a volumetric model of the scene from calibrated cameras by explicitly modeling and detecting occlusions. We present a brief overview of the state of the art in such methods for multi-view reconstruction. In particular, algorithms based on a probabilistic framework have become quite popular and produce very accurate models. Several such probabilistic volume reconstruction methods will be described. For the dynamic parts of the scene, where an online reconstruction is needed, simpler methods are required. An important case of such scenes is that of walking people in a surveillance scenario. For this case, we present fast online algorithms that recover approximate shape and appearance models and 3D trajectories of people as they walk in the scene. Finally, we address the problem of optimal placement of cameras in order to acquire the best possible image data for the reconstruction of a given scene according to the particular task specification. ER - TY - JOUR T1 - Network Visualization by Semantic Substrates JF - IEEE Transactions on Visualization and Computer Graphics Y1 - 2006 A1 - Shneiderman, Ben A1 - Aris,A. KW - Automatic control KW - data visualisation KW - Data visualization KW - Displays KW - Filters KW - Graphical user interfaces KW - Information Visualization KW - information visualization designers KW - Law KW - legal citations KW - Legal factors KW - legal precedent data KW - network visualization KW - NVSS 1.0 KW - scalability KW - semantic substrate KW - Terminology KW - Tunneling KW - user-defined semantic substrates AB - Networks have remained a challenge for information visualization designers because of the complex issues of node and link layout coupled with the rich set of tasks that users present. This paper offers a strategy based on two principles: (1) layouts are based on user-defined semantic substrates, which are non-overlapping regions in which node placement is based on node attributes, (2) users interactively adjust sliders to control link visibility to limit clutter and thus ensure comprehensibility of source and destination. Scalability is further facilitated by user control of which nodes are visible. We illustrate our semantic substrates approach as implemented in NVSS 1.0 with legal precedent data for up to 1122 court cases in three regions with 7645 legal citations VL - 12 SN - 1077-2626 CP - 5 M3 - 10.1109/TVCG.2006.166 ER - TY - JOUR T1 - Nuclear Envelope Dystrophies Show a Transcriptional Fingerprint Suggesting Disruption of Rb–MyoD Pathways in Muscle Regeneration JF - BrainBrain Y1 - 2006 A1 - Bakay,Marina A1 - Wang,Zuyi A1 - Melcon,Gisela A1 - Schiltz,Louis A1 - Xuan,Jianhua A1 - Zhao,Po A1 - Sartorelli,Vittorio A1 - Seo,Jinwook A1 - Pegoraro,Elena A1 - Angelini,Corrado A1 - Shneiderman, Ben A1 - Escolar,Diana A1 - Chen,Yi-Wen A1 - Winokur,Sara T A1 - Pachman,Lauren M A1 - Fan,Chenguang A1 - Mandler,Raul A1 - Nevo,Yoram A1 - Gordon,Erynn A1 - Zhu,Yitan A1 - Dong,Yibin A1 - Wang,Yue A1 - Hoffman,Eric P KW - EDMD = Emery–Dreifuss muscular dystrophy KW - emerin KW - Emery-Dreifuss muscular dystrophy KW - FSHD = fascioscapulohumeral muscular dystrophy KW - IDG = individual discriminatory genes KW - JDG = jointly discriminatory genes KW - lamin A/C KW - LGMD = limb-girdle muscular dystrophy KW - LOO = leave-one-out KW - RT–PCR = reverse transcription–polymerase chain reaction; VISDA = Visual and Statistical Data Analyzer KW - Skeletal muscle KW - wFC = weighted Fisher criterion AB - Mutations of lamin A/C (LMNA) cause a wide range of human disorders, including progeria, lipodystrophy, neuropathies and autosomal dominant Emery–Dreifuss muscular dystrophy (EDMD). EDMD is also caused by X-linked recessive loss-of-function mutations of emerin, another component of the inner nuclear lamina that directly interacts with LMNA. One model for disease pathogenesis of LMNA and emerin mutations is cell-specific perturbations of the mRNA transcriptome in terminally differentiated cells. To test this model, we studied 125 human muscle biopsies from 13 diagnostic groups (125 U133A, 125 U133B microarrays), including EDMD patients with LMNA and emerin mutations. A Visual and Statistical Data Analyzer (VISDA) algorithm was used to statistically model cluster hierarchy, resulting in a tree of phenotypic classifications. Validations of the diagnostic tree included permutations of U133A and U133B arrays, and use of two probe set algorithms (MAS5.0 and MBEI). This showed that the two nuclear envelope defects (EDMD LMNA, EDMD emerin) were highly related disorders and were also related to fascioscapulohumeral muscular dystrophy (FSHD). FSHD has recently been hypothesized to involve abnormal interactions of chromatin with the nuclear envelope. To identify disease-specific transcripts for EDMD, we applied a leave-one-out (LOO) cross-validation approach using LMNA patient muscle as a test data set, with reverse transcription–polymerase chain reaction (RT–PCR) validations in both LMNA and emerin patient muscle. A high proportion of top-ranked and validated transcripts were components of the same transcriptional regulatory pathway involving Rb1 and MyoD during muscle regeneration (CRI-1, CREBBP, Nap1L1, ECREBBP/p300), where each was specifically upregulated in EDMD. Using a muscle regeneration time series (27 time points) we develop a transcriptional model for downstream consequences of LMNA and emerin mutations. We propose that key interactions between the nuclear envelope and Rb and MyoD fail in EDMD at the point of myoblast exit from the cell cycle, leading to poorly coordinated phosphorylation and acetylation steps. Our data is consistent with mutations of nuclear lamina components leading to destabilization of the transcriptome in differentiated cells. VL - 129 SN - 0006-8950, 1460-2156 UR - http://brain.oxfordjournals.org/content/129/4/996 CP - 4 M3 - 10.1093/brain/awl023 ER - TY - JOUR T1 - Open problems in relational data clustering JF - Proceedings of the ICML Workshop on Open Problems in Stastistical Relational Learning Y1 - 2006 A1 - Anthony,A. A1 - desJardins, Marie AB - Data clustering is the task of detecting pat-terns in a set of data. Most algorithms take non-relational data as input and are sometimes unable to find significant patterns. Many data sets can include relational infor- mation, as well as independent object at- tributes. We believe that clustering with re- lational data will help find significant pat- terns where non-relational algorithms fail. This paper discusses two open problems in relational data clustering: clustering hetero- geneous data, and relation selection or ex- traction. Potential methods for addressing the problems are presented. ER - TY - RPRT T1 - OverDoSe: A generic DDoS protection service using an overlay network Y1 - 2006 A1 - Elaine Shi A1 - Stoica,I. A1 - Andersen,D.G. A1 - Perrig, A. AB - We present the design and implementation of OverDoSe, an overlay network offering generic DDoS protection for targeted sites. OverDoSe clients and servers are isolated at the IP level. Overlay nodes route packets between a client and a server, and regulate traffic according to the server’s instructions. Through the use of light-weight security primitives, OverDoSe achieves resilience against compromised overlay nodes with a minimal performance overhead. OverDoSe can be deployed by a single ISP who wishes to offer DDoS protection as a value-adding service to its customers. PB - School of Computer Science, Carnegie Mellon University SN - CMU-CS-06-114 UR - http://repository.cmu.edu/cgi/viewcontent.cgi?article=1073&context=compsci M3 - Technical Report ER - TY - CONF T1 - Partially overlapped channels not considered harmful T2 - Proceedings of the joint international conference on Measurement and modeling of computer systems Y1 - 2006 A1 - Mishra,A. A1 - Shrivastava,V. A1 - Banerjee,S. A1 - Arbaugh, William A. JA - Proceedings of the joint international conference on Measurement and modeling of computer systems ER - TY - JOUR T1 - The priority curve algorithm for video summarization JF - Information Systems Y1 - 2006 A1 - Albanese, M. A1 - Fayzullin,M. A1 - Picariello, A. A1 - V.S. Subrahmanian KW - Content based retrieval KW - Video databases KW - Video summarization AB - In this paper, we introduce the concept of a priority curve associated with a video. We then provide an algorithm that can use the priority curve to create a summary (of a desired length) of any video. The summary thus created exhibits nice continuity properties and also avoids repetition. We have implemented the priority curve algorithm (PriCA) and compared it with other summarization algorithms in the literature with respect to both performance and the output quality. The quality of summaries was evaluated by a group of 200 students in Naples, Italy, who watched soccer videos. We show that PriCA is faster than existing algorithms and also produces better quality summaries. We also briefly describe a soccer video summarization system we have built on using the PriCA architecture and various (classical) image processing algorithms. VL - 31 SN - 0306-4379 UR - http://www.sciencedirect.com/science/article/pii/S0306437905001250 CP - 7 M3 - 10.1016/j.is.2005.12.003 ER - TY - CONF T1 - A probabilistic notion of correspondence and the epipolar constraint T2 - Proceedings of the Third International Symposium on 3D Data Processing, Visualization, and Transmission (3DPVT'06) Y1 - 2006 A1 - Domke, J. A1 - Aloimonos, J. JA - Proceedings of the Third International Symposium on 3D Data Processing, Visualization, and Transmission (3DPVT'06) ER - TY - JOUR T1 - Provable algorithms for parallel generalized sweep scheduling JF - Journal of Parallel and Distributed Computing Y1 - 2006 A1 - Anil Kumar,V. S A1 - Marathe,M. V A1 - Parthasarathy,S. A1 - Srinivasan, Aravind A1 - Zust,S. VL - 66 CP - 6 ER - TY - BOOK T1 - Real-Time Distributed Algorithms for Visual and Battlefield Reasoning Y1 - 2006 A1 - Davis, Larry S. A1 - Basili, Victor R. A1 - V.S. Subrahmanian A1 - Reggia, James A. A1 - Aloimonos, J. AB - Information is key to the success of the next generation battlefield. There is a critical need to determine, in real-time, what the enemy is doing, and to interpret that information in the context of past related events. In this project we examined two aspects of this issue: development of a high-level task definition language for tasking a network of sensors to carry out given objectives, and interpreting recounted events so that past related scenarios could be automatically identified from a case database. PB - MARYLAND UNIV COLLEGE PARK OFFICE OF RESEARCH ADMINISTRATION AND ADVANCEMENT ER - TY - CONF T1 - Real-Time Human Detection, Tracking, and Verification in Uncontrolled Camera Motion Environments T2 - Computer Vision Systems, 2006 ICVS '06. IEEE International Conference on Y1 - 2006 A1 - Hussein,M. A1 - Abd-Almageed, Wael A1 - Yang Ran A1 - Davis, Larry S. AB - In environments where a camera is installed on a freely moving platform, e.g. a vehicle or a robot, object detection and tracking becomes much more difficult. In this paper, we presents a real time system for human detection, tracking, and verification in such challenging environments. To deliver a robust performance, the system integrates several computer vision algorithms to perform its function: a human detection algorithm, an object tracking algorithm, and a motion analysis algorithm. To utilize the available computing resources to the maximum possible extent, each of the system components is designed to work in a separate thread that communicates with the other threads through shared data structures. The focus of this paper is more on the implementation issues than on the algorithmic issues of the system. Object oriented design was adopted to abstract algorithmic details away from the system structure. JA - Computer Vision Systems, 2006 ICVS '06. IEEE International Conference on M3 - 10.1109/ICVS.2006.52 ER - TY - JOUR T1 - Robust ego-motion estimation and 3-D model refinement using surface parallax JF - Image Processing, IEEE Transactions on Y1 - 2006 A1 - Agrawal,A. A1 - Chellapa, Rama KW - 3D model refinement KW - algorithms KW - Artificial intelligence KW - Automated;Subtraction Technique; KW - Computer-Assisted;Imaging KW - constant parallax model KW - depth based parallax model KW - digital elevation map KW - epipolar field KW - Image Enhancement KW - Image Interpretation KW - iterative algorithm KW - iterative methods KW - Motion estimation KW - robust ego-motion estimation KW - smooth parallax field KW - surface parallax KW - Three-Dimensional;Information Storage and Retrieval;Pattern Recognition AB - We present an iterative algorithm for robustly estimating the ego-motion and refining and updating a coarse depth map using parametric surface parallax models and brightness derivatives extracted from an image pair. Given a coarse depth map acquired by a range-finder or extracted from a digital elevation map (DEM), ego-motion is estimated by combining a global ego-motion constraint and a local brightness constancy constraint. Using the estimated camera motion and the available depth estimate, motion of the three-dimensional (3-D) points is compensated. We utilize the fact that the resulting surface parallax field is an epipolar field, and knowing its direction from the previous motion estimates, estimate its magnitude and use it to refine the depth map estimate. The parallax magnitude is estimated using a constant parallax model (CPM) which assumes a smooth parallax field and a depth based parallax model (DBPM), which models the parallax magnitude using the given depth map. We obtain confidence measures for determining the accuracy of the estimated depth values which are used to remove regions with potentially incorrect depth estimates for robustly estimating ego-motion in subsequent iterations. Experimental results using both synthetic and real data (both indoor and outdoor sequences) illustrate the effectiveness of the proposed algorithm. VL - 15 SN - 1057-7149 CP - 5 M3 - 10.1109/TIP.2005.864167 ER - TY - JOUR T1 - Seasonal Cholera Caused by Vibrio Cholerae Serogroups O1 and O139 in the Coastal Aquatic Environment of Bangladesh JF - Applied and Environmental MicrobiologyAppl. Environ. Microbiol. Y1 - 2006 A1 - Alam,Munirul A1 - Hasan,Nur A. A1 - Sadique,Abdus A1 - Bhuiyan,N. A. A1 - Ahmed,Kabir U. A1 - Nusrin,Suraia A1 - Nair,G. Balakrish A1 - Siddique,A. K. A1 - Sack,R. Bradley A1 - Sack,David A. A1 - Huq,Anwar A1 - Rita R Colwell AB - Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae. VL - 72 SN - 0099-2240, 1098-5336 UR - http://aem.asm.org/content/72/6/4096 CP - 6 M3 - 10.1128/AEM.00066-06 ER - TY - CONF T1 - A sensory grammar for inferring behaviors in sensor networks T2 - Proceedings of the 5th international conference on Information processing in sensor networks Y1 - 2006 A1 - Lymberopoulos, Dimitrios A1 - Ogale, Abhijit S. A1 - Savvides, Andreas A1 - Aloimonos, J. KW - algorithms KW - behavior identification KW - human activity KW - human factors KW - pcfg KW - real-time and embedded systems KW - sensor grammars KW - sensor networks AB - The ability of a sensor network to parse out observable activities into a set of distinguishable actions is a powerful feature that can potentially enable many applications of sensor networks to everyday life situations. In this paper we introduce a framework that uses a hierarchy of Probabilistic Context Free Grammars (PCFGs) to perform such parsing. The power of the framework comes from the hierarchical organization of grammars that allows the use of simple local sensor measurements for reasoning about more macroscopic behaviors. Our presentation describes how to use a set of phonemes to construct grammars and how to achieve distributed operation using a messaging model. The proposed framework is flexible. It can be mapped to a network hierarchy or can be applied sequentially and across the network to infer behaviors as they unfold in space and time. We demonstrate this functionality by inferring simple motion patterns using a sequence of simple direction vectors obtained from our camera sensor network testbed. JA - Proceedings of the 5th international conference on Information processing in sensor networks T3 - IPSN '06 PB - ACM CY - Nashville, Tennessee, USA SN - 1-59593-334-4 M3 - 10.1145/1127777.1127817 ER - TY - CONF T1 - A Sensory-Motor Language for Human Activity Understanding T2 - 2006 6th IEEE-RAS International Conference on Humanoid Robots Y1 - 2006 A1 - Guerra-Filho,G. A1 - Aloimonos, J. KW - Actuators KW - associative learning KW - atomic segments KW - computational linguistics KW - Computer science KW - Computer vision KW - Educational institutions KW - grammars KW - human activity language KW - human activity understanding KW - human movement syntax KW - Humanoid robots KW - HUMANS KW - joint angles KW - kinetemes KW - kinetological system KW - Laboratories KW - learning (artificial intelligence) KW - List key index terms here KW - Morphology KW - motor information KW - No mare than 5 KW - parallel learning KW - Reproducibility of results KW - Robot kinematics KW - Robot programming KW - robot vision KW - sensory-motor language KW - sequential language learning KW - symbolic nonarbitrary representation KW - visual information AB - We have empirically discovered that the space of human actions has a linguistic framework. This is a sensory-motor space consisting of the evolution of the joint angles of the human body in movement. The space of human activity has its own phonemes, morphemes, and sentences. We present a human activity language (HAL) for symbolic non-arbitrary representation of visual and motor information. In phonology, we define atomic segments (kinetemes) that are used to compose human activity. We introduce the concept of a kinetological system and propose five basic properties for such a system: compactness, view-invariance, reproducibility, selectivity, and reconstructivity. In morphology, we extend sequential language learning to incorporate associative learning with our parallel learning approach. Parallel learning is effective in identifying the kinetemes and active joints in a particular action. In syntax, we suggest four lexical categories for our human activity language (noun, verb, adjective, and adverb). These categories are combined into sentences through syntax for human movement JA - 2006 6th IEEE-RAS International Conference on Humanoid Robots PB - IEEE SN - 1-4244-0200-X M3 - 10.1109/ICHR.2006.321365 ER - TY - JOUR T1 - Session 8A-Combinatorial Optimization and Quantum Computing-Lower Bounds on the Deterministic and Quantum Communication Complexities of Hamming-Distance Problems JF - Lecture Notes in Computer Science Y1 - 2006 A1 - Ambainis,A. A1 - Gasarch,W. A1 - Srinivasan, Aravind A1 - Utis,A. VL - 4288 ER - TY - CONF T1 - A structural approach to latency prediction T2 - Proceedings of the 6th ACM SIGCOMM conference on Internet measurement Y1 - 2006 A1 - Madhyastha,Harsha V. A1 - Anderson,Thomas A1 - Krishnamurthy,Arvind A1 - Spring, Neil A1 - Venkataramani,Arun KW - internet topology KW - latency prediction KW - route measurements AB - Several models have been recently proposed for predicting the latency of end to end Internet paths. These models treat the Internet as a black-box, ignoring its internal structure. While these models are simple, they can often fail systematically; for example, the most widely used models use metric embeddings that predict no benefit to detour routes even though half of all Internet routes can benefit from detours.In this paper, we adopt a structural approach that predicts path latency based on measurements of the Internet's routing topology, PoP connectivity, and routing policy. We find that our approach outperforms Vivaldi, the most widely used black-box model. Furthermore, unlike metric embeddings, our approach successfully predicts 65% of detour routes in the Internet. The number of measurements used in our approach is comparable with that required by black box techniques, but using traceroutes instead of pings. JA - Proceedings of the 6th ACM SIGCOMM conference on Internet measurement T3 - IMC '06 PB - ACM CY - New York, NY, USA SN - 1-59593-561-4 UR - http://doi.acm.org/10.1145/1177080.1177092 M3 - 10.1145/1177080.1177092 ER - TY - PAT T1 - System and method for locating a closest server in response to a client ... Y1 - 2006 A1 - Andrews,Matthew A1 - Hofmann,Markus A1 - Shepherd,Bruce A1 - Srinivasan, Aravind A1 - Winkler,Peter A1 - Zane,Francis ED - Lucent Technologies Inc. AB - A scalable system and method for locating a closest server in response to a client request via an interactive distribution network, such as the Internet, are provided. A closest content server is defined as having the least round trip time for responding to a client request. The system including a plurality of content servers; and a local server in communication with a plurality of clients, the local server acting as a proxy for communicating client requests from clients to a redirection server. Client network distance and load information is periodically collected at each content server in the network from clients communicating with each of the respective content servers. The redirection server periodically aggregates the network distance and load information from each content server to create client clusters from both current and previously aggregated network distance and load information. Each client cluster represents a division or partition of the total IP address space. Each... VL - 09/726,192 UR - http://www.google.com/patents?id=cE54AAAAEBAJ CP - 7020698 ER - TY - CONF T1 - Towards a sensorimotor WordNet SM: Closing the semantic gap T2 - Proc. of the International WordNet Conference (GWC) Y1 - 2006 A1 - Guerra-Filho,G. A1 - Aloimonos, J. JA - Proc. of the International WordNet Conference (GWC) ER - TY - JOUR T1 - Toxigenic Vibrio Cholerae in the Aquatic Environment of Mathbaria, Bangladesh JF - Applied and Environmental MicrobiologyAppl. Environ. Microbiol. Y1 - 2006 A1 - Alam,Munirul A1 - Sultana,Marzia A1 - Nair,G. Balakrish A1 - Sack,R. Bradley A1 - Sack,David A. A1 - Siddique,A. K. A1 - Ali,Afsar A1 - Huq,Anwar A1 - Rita R Colwell AB - Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods. Biweekly environmental surveillance for V. cholerae was carried out in Mathbaria, an area of cholera endemicity adjacent to the Bay of Bengal, with the focus on V. cholerae O1 and O139 Bengal. A total of 297 samples of water, phytoplankton, and zooplankton were collected between March and December 2004, yielding eight V. cholerae O1 and four O139 Bengal isolates. A combination of culture methods, multiplex-PCR, and direct fluorescent antibody (DFA) counting revealed the Mathbaria aquatic environment to be a reservoir for V. cholerae O1 and O139 Bengal. DFA results showed significant clumping of the bacteria during the interepidemic period for cholera, and the fluorescent micrographs revealed large numbers of V. cholerae O1 in thin films of exopolysaccharides (biofilm). A similar clumping of V. cholerae O1 was also observed in samples collected from Matlab, Bangladesh, where cholera also is endemic. Thus, the results of the study provided in situ evidence for V. cholerae O1 and O139 in the aquatic environment, predominantly as viable but nonculturable cells and culturable cells in biofilm consortia. The biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of cholera in Bangladesh. VL - 72 SN - 0099-2240, 1098-5336 UR - http://aem.asm.org/content/72/4/2849 CP - 4 M3 - 10.1128/AEM.72.4.2849-2855.2006 ER - TY - CONF T1 - Tracking Articulating Objects from Ground Vehicles using Mixtures of Mixtures T2 - Intelligent Robots and Systems, 2006 IEEE/RSJ International Conference on Y1 - 2006 A1 - Abd-Almageed, Wael A1 - Hussein,M. A1 - Davis, Larry S. KW - articulating KW - filter;unmanned KW - ground KW - information;mixtures KW - mixtures;particle KW - objects KW - of KW - operated KW - tracking;egomotion KW - vehicle;remotely KW - vehicles;robot KW - vision; AB - An algorithm for tracking articulating objects from moving camera platforms is presented. Mixtures of mixtures are used to model the appearance of the object and the background. The state of the object is tracked using a particle filter. Egomotion information are estimated and used to set the state variance of the particle filter. Results of tracking human objects from an unmanned ground vehicle are used to evaluate the tracking algorithm JA - Intelligent Robots and Systems, 2006 IEEE/RSJ International Conference on M3 - 10.1109/IROS.2006.281881 ER - TY - JOUR T1 - Understanding visuo‐motor primitives for motion synthesis and analysis JF - Computer Animation and Virtual Worlds Y1 - 2006 A1 - Guerra‐Filho,Gutemberg A1 - Aloimonos, J. KW - compression KW - motion synthesis KW - visuo‐motor primitives AB - The problem addressed in this paper concerns the representation of human movement in terms of atomic visuo-motor primitives considering both generation and perception of movement. We introduce the concept of kinetology, the phonology of human movement, and five principles on which such a system should be based: compactness, view-invariance, reproducibility, selectivity, and reconstructivity. We propose visuo-motor primitives and demonstrate their kinetological properties. Further evaluation is accomplished with experiments on compression and decompression. Our long-term goal is to demonstrate that action has a space characterized by a visuo-motor language. Copyright © 2006 John Wiley & Sons, Ltd. VL - 17 SN - 1546-427X UR - http://onlinelibrary.wiley.com/doi/10.1002/cav.124/abstract CP - 3‐4 M3 - 10.1002/cav.124 ER - TY - CHAP T1 - What Is the Range of Surface Reconstructions from a Gradient Field? T2 - Computer Vision – ECCV 2006Computer Vision – ECCV 2006 Y1 - 2006 A1 - Agrawal,Amit A1 - Raskar,Ramesh A1 - Chellapa, Rama ED - Leonardis,Aleš ED - Bischof,Horst ED - Pinz,Axel AB - We propose a generalized equation to represent a continuum of surface reconstruction solutions of a given non-integrable gradient field. We show that common approaches such as Poisson solver and Frankot-Chellappa algorithm are special cases of this generalized equation. For a N × N pixel grid, the subspace of all integrable gradient fields is of dimension N 2 – 1. Our framework can be applied to derive a range of meaningful surface reconstructions from this high dimensional space. The key observation is that the range of solutions is related to the degree of anisotropy in applying weights to the gradients in the integration process. While common approaches use isotropic weights, we show that by using a progression of spatially varying anisotropic weights, we can achieve significant improvement in reconstructions. We propose (a) α-surfaces using binary weights, where the parameter α allows trade off between smoothness and robustness, (b) M-estimators and edge preserving regularization using continuous weights and (c) Diffusion using affine transformation of gradients. We provide results on photometric stereo, compare with previous approaches and show that anisotropic treatment discounts noise while recovering salient features in reconstructions. JA - Computer Vision – ECCV 2006Computer Vision – ECCV 2006 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3951 SN - 978-3-540-33832-1 UR - http://dx.doi.org/10.1007/11744023_45 ER - TY - JOUR T1 - Wireless Network Security and Interworking JF - Proceedings of the IEEE Y1 - 2006 A1 - Shin,M. A1 - Ma,J. A1 - Mishra,A. A1 - Arbaugh, William A. KW - 3G mobile communication KW - 3G systems KW - Authentication KW - Bandwidth KW - Communication system security KW - computer network security KW - computer security KW - Data security KW - internetworking KW - Land mobile radio cellular systems KW - Paper technology KW - security architectures KW - security of data KW - telecommunication security KW - wireless communication KW - wireless communications KW - Wireless LAN KW - wireless network security KW - Wireless networks KW - wireless technologies KW - WLAN systems AB - A variety of wireless technologies have been standardized and commercialized, but no single technology is considered the best because of different coverage and bandwidth limitations. Thus, interworking between heterogeneous wireless networks is extremely important for ubiquitous and high-performance wireless communications. Security in interworking is a major challenge due to the vastly different security architectures used within each network. The goal of this paper is twofold. First, we provide a comprehensive discussion of security problems and current technologies in 3G and WLAN systems. Second, we provide introductory discussions about the security problems in interworking, the state-of-the-art solutions, and open problems. VL - 94 SN - 0018-9219 CP - 2 M3 - 10.1109/JPROC.2005.862322 ER - TY - CHAP T1 - 3D Facial Pose Tracking in Uncalibrated Videos T2 - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence Y1 - 2005 A1 - Aggarwal,Gaurav A1 - Veeraraghavan,Ashok A1 - Chellapa, Rama ED - Pal,Sankar ED - Bandyopadhyay,Sanghamitra ED - Biswas,Sambhunath AB - This paper presents a method to recover the 3D configuration of a face in each frame of a video. The 3D configuration consists of the 3 translational parameters and the 3 orientation parameters which correspond to the yaw, pitch and roll of the face, which is important for applications like face modeling, recognition, expression analysis, etc. The approach combines the structural advantages of geometric modeling with the statistical advantages of a particle-filter based inference. The face is modeled as the curved surface of a cylinder which is free to translate and rotate arbitrarily. The geometric modeling takes care of pose and self-occlusion while the statistical modeling handles moderate occlusion and illumination variations. Experimental results on multiple datasets are provided to show the efficacy of the approach. The insensitivity of our approach to calibration parameters (focal length) is also shown. JA - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3776 SN - 978-3-540-30506-4 UR - http://dx.doi.org/10.1007/11590316_81 ER - TY - CONF T1 - An algebraic approach to surface reconstruction from gradient fields T2 - Computer Vision, 2005. ICCV 2005. Tenth IEEE International Conference on Y1 - 2005 A1 - Agrawal,A. A1 - Chellapa, Rama A1 - Raskar, R. KW - algebra; KW - algebraic KW - approach; KW - Computer KW - confinement; KW - discrete KW - domain KW - error KW - field; KW - from KW - gradient KW - graph KW - image KW - integrability; KW - linear KW - local KW - methods; KW - photometric KW - reconstruction; KW - shading; KW - SHAPE KW - stereo; KW - surface KW - system; KW - theory; KW - vision; AB - Several important problems in computer vision such as shape from shading (SFS) and photometric stereo (PS) require reconstructing a surface from an estimated gradient field, which is usually non-integrable, i.e. have non-zero curl. We propose a purely algebraic approach to enforce integrability in discrete domain. We first show that enforcing integrability can be formulated as solving a single linear system Ax =b over the image. In general, this system is under-determined. We show conditions under which the system can be solved and a method to get to those conditions based on graph theory. The proposed approach is non-iterative, has the important property of local error confinement and can be applied to several problems. Results on SFS and PS demonstrate the applicability of our method. JA - Computer Vision, 2005. ICCV 2005. Tenth IEEE International Conference on VL - 1 M3 - 10.1109/ICCV.2005.31 ER - TY - CONF T1 - Alignment link projection using transformation-based learning T2 - Proceedings of the conference on Human Language Technology and Empirical Methods in Natural Language Processing Y1 - 2005 A1 - Ayan,Necip Fazil A1 - Dorr, Bonnie J A1 - Monz,Christof AB - We present a new word-alignment approach that learns errors made by existing word alignment systems and corrects them. By adapting transformation-based learning to the problem of word alignment, we project new alignment links from already existing links, using features such as POS tags. We show that our alignment link projection approach yields a significantly lower alignment error rate than that of the best performing alignment system (22.6% relative reduction on English-Spanish data and 23.2% relative reduction on English-Chinese data). JA - Proceedings of the conference on Human Language Technology and Empirical Methods in Natural Language Processing T3 - HLT '05 PB - Association for Computational Linguistics CY - Stroudsburg, PA, USA UR - http://dx.doi.org/10.3115/1220575.1220599 M3 - 10.3115/1220575.1220599 ER - TY - JOUR T1 - Applications of SHOP and SHOP2 JF - Intelligent Systems, IEEE Y1 - 2005 A1 - Nau, Dana S. A1 - Au,T.-C. A1 - Ilghami,O. A1 - Kuter,U. A1 - Wu,D. A1 - Yaman,F. A1 - Munoz-Avila,H. A1 - Murdock,J. W. KW - automated planning KW - hierarchical task network planning KW - ordered task decomposition KW - planning (artificial intelligence) KW - problem solving KW - search-control strategy KW - simple hierarchical ordered planner KW - trees (mathematics) KW - uncertainty handling AB - We design the simple hierarchical ordered planner (SHOP) and its successor, SHOP2, with two goals in mind: to investigate research issues in automated planning and to provide some simple, practical planning tools. SHOP and SHOP2 are based on a planning formalism called hierarchical task network planning. SHOP and SHOP2 use a search-control strategy called ordered task decomposition, which breaks tasks into subtasks and generates the plan's actions in the same order that the plan executor executes them. So, throughout the planning process, the planner can tell what the state of the world at each step of the plan. VL - 20 SN - 1541-1672 CP - 2 M3 - 10.1109/MIS.2005.20 ER - TY - CONF T1 - An architectural level design methodology for embedded face detection T2 - Proceedings of the 3rd IEEE/ACM/IFIP international conference on Hardware/software codesign and system synthesis Y1 - 2005 A1 - Kianzad,V. A1 - Saha,S. A1 - Schlessman,J. A1 - Aggarwal,G. A1 - Bhattacharyya, Shuvra S. A1 - Wolf,W. A1 - Chellapa, Rama KW - design space exploration KW - Face detection KW - platforms KW - reconfigurable KW - system-level models AB - Face detection and recognition research has attracted great attention in recent years. Automatic face detection has great potential in a large array of application areas, including banking and security system access control, video surveillance, and multimedia information retrieval. In this paper, we discuss an architectural level design methodology for implementation of an embedded face detection system on a reconfigurable system on chip. We present models for performance estimation and validate these models with experimental values obtained from implementing our system on an FPGA platform. This modeling approach is shown to be efficient, accurate, and intuitive for designers to work with. Using this approach, we present several design options that trade-off various architectural features. JA - Proceedings of the 3rd IEEE/ACM/IFIP international conference on Hardware/software codesign and system synthesis T3 - CODES+ISSS '05 PB - ACM CY - New York, NY, USA SN - 1-59593-161-9 UR - http://doi.acm.org/10.1145/1084834.1084872 M3 - 10.1145/1084834.1084872 ER - TY - JOUR T1 - Chromatic Induction and Perspective Distortion JF - Journal of VisionJ Vis Y1 - 2005 A1 - Aloimonos, J. A1 - Fermüller, Cornelia AB - A pattern presented by Robertson (1996), consisting of yellow and blue square waves with red squares superimposed on either the blue or yellow bands give rise to assimilation effects similar as in the White illusion. The red squares on the yellow bands appear more blue, and the red squares on the blue bands appear more yellow. Varying the position and orientation of the pattern in space changes the effect. For example, slanting the pattern or increasing the distance to the pattern in space increases the effect. But rotating the pattern by 90 degrees and slanting it, nearly eliminates the effect. These changes in color appearance can be explained as the result of averaging in receptive field of extended size.Due to perspective distortion, the area of the pattern in space mapping to an image patch changes with the position and orientation of the pattern. A computational simulation, implementing the distortion from 3D space to image space, followed by a color segmentation (k-means clustering) gave the same color distortion and segmentation as perceived. Thus the effect seems to be simple an artifact of sampling which causes averaging or smoothing with some filters. We propose the hypothesis that chromatic induction, which takes the two forms of chromatic contrast and assimilation, results, because the system samples with large fields and following in the segmentation stage attempts to compensate for the averaging effects in neighboring regions VL - 5 SN - , 1534-7362 UR - http://www.journalofvision.org/content/5/8/1026 CP - 8 M3 - 10.1167/5.8.1026 ER - TY - JOUR T1 - Comparative Genomics of Trypanosomatid Parasitic Protozoa JF - Science Y1 - 2005 A1 - El‐Sayed, Najib M. A1 - Myler,Peter J. A1 - Blandin,Gaëlle A1 - Berriman,Matthew A1 - Crabtree,Jonathan A1 - Aggarwal,Gautam A1 - Caler,Elisabet A1 - Renauld,Hubert A1 - Worthey,Elizabeth A. A1 - Hertz-Fowler,Christiane A1 - Ghedin,Elodie A1 - Peacock,Christopher A1 - Bartholomeu,Daniella C. A1 - Haas,Brian J. A1 - Tran,Anh-Nhi A1 - Wortman,Jennifer R. A1 - Alsmark,U. Cecilia M. A1 - Angiuoli,Samuel A1 - Anupama,Atashi A1 - Badger,Jonathan A1 - Bringaud,Frederic A1 - Cadag,Eithon A1 - Carlton,Jane M. A1 - Cerqueira,Gustavo C. A1 - Creasy,Todd A1 - Delcher,Arthur L. A1 - Djikeng,Appolinaire A1 - Embley,T. Martin A1 - Hauser,Christopher A1 - Ivens,Alasdair C. A1 - Kummerfeld,Sarah K. A1 - Pereira-Leal,Jose B. A1 - Nilsson,Daniel A1 - Peterson,Jeremy A1 - Salzberg,Steven L. A1 - Shallom,Joshua A1 - Silva,Joana C. A1 - Sundaram,Jaideep A1 - Westenberger,Scott A1 - White,Owen A1 - Melville,Sara E. A1 - Donelson,John E. A1 - Andersson,Björn A1 - Stuart,Kenneth D. A1 - Hall,Neil AB - A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that—along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions—have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont. VL - 309 UR - http://www.sciencemag.org/content/309/5733/404.abstract CP - 5733 M3 - 10.1126/science.1112181 ER - TY - CONF T1 - Comparing the Performance of High-Level Middleware Systems in Shared and Distributed Memory Parallel Environments T2 - Parallel and Distributed Processing Symposium, 2005. Proceedings. 19th IEEE International Y1 - 2005 A1 - Kim,Jik-Soo A1 - Andrade,H. A1 - Sussman, Alan KW - Application software KW - Computer science KW - Computer vision KW - Data analysis KW - Distributed computing KW - distributed computing environment KW - distributed memory parallel environment KW - distributed shared memory systems KW - Educational institutions KW - high-level middleware system KW - I/O-intensive data analysis application KW - Libraries KW - Middleware KW - parallel computing environment KW - parallel library support KW - parallel memories KW - programming language KW - programming languages KW - Runtime environment KW - shared memory parallel environment KW - Writing AB - The utilization of toolkits for writing parallel and/or distributed applications has been shown to greatly enhance developer's productivity. Such an approach hides many of the complexities associated with writing these applications, rather than relying solely on programming language aids and parallel library support, such as MPI or PVM. In this work, we evaluate three different middleware systems that have been used to implement a computation and I/O-intensive data analysis application from the domain of computer vision. This study shows the benefits and overheads associated with each of the middleware systems, in different homogeneous computational environments and with different workloads. Our results lead the way toward being able to make better decisions for tuning the application environment, for selecting the appropriate middleware, and also for designing more powerful middleware systems to efficiently build and run highly complex applications in both parallel and distributed computing environments. JA - Parallel and Distributed Processing Symposium, 2005. Proceedings. 19th IEEE International PB - IEEE SN - 0-7695-2312-9 M3 - 10.1109/IPDPS.2005.144 ER - TY - JOUR T1 - Critical Factors Influencing the Occurrence of Vibrio Cholerae in the Environment of Bangladesh JF - Applied and Environmental MicrobiologyAppl. Environ. Microbiol. Y1 - 2005 A1 - Huq,Anwar A1 - Sack,R. Bradley A1 - Nizam,Azhar A1 - Longini,Ira M. A1 - Nair,G. Balakrish A1 - Ali,Afsar A1 - Morris,J. Glenn A1 - Khan,M. N. Huda A1 - Siddique,A. Kasem A1 - Yunus,Mohammed A1 - Albert,M. John A1 - Sack,David A. A1 - Rita R Colwell AB - The occurrence of outbreaks of cholera in Africa in 1970 and in Latin America in 1991, mainly in coastal communities, and the appearance of the new serotype Vibrio cholerae O139 in India and subsequently in Bangladesh have stimulated efforts to understand environmental factors influencing the growth and geographic distribution of epidemic Vibrio cholerae serotypes. Because of the severity of recent epidemics, cholera is now being considered by some infectious disease investigators as a “reemerging” disease, prompting new work on the ecology of vibrios. Epidemiological and ecological surveillance for cholera has been under way in four rural, geographically separated locations in Bangladesh for the past 4 years, during which both clinical and environmental samples were collected at biweekly intervals. The clinical epidemiology portion of the research has been published (Sack et al., J. Infect. Dis. 187:96-101, 2003). The results of environmental sampling and analysis of the environmental and clinical data have revealed significant correlations of water temperature, water depth, rainfall, conductivity, and copepod counts with the occurrence of cholera toxin-producing bacteria (presumably V. cholerae). The lag periods between increases or decreases in units of factors, such as temperature and salinity, and occurrence of cholera correlate with biological parameters, e.g., plankton population blooms. The new information on the ecology of V. cholerae is proving useful in developing environmental models for the prediction of cholera epidemics. VL - 71 SN - 0099-2240, 1098-5336 UR - http://aem.asm.org/content/71/8/4645 CP - 8 M3 - 10.1128/AEM.71.8.4645-4654.2005 ER - TY - CHAP T1 - Detecting Independent 3D Movement T2 - Handbook of Geometric ComputingHandbook of Geometric Computing Y1 - 2005 A1 - Corrochano,Eduardo Bayro A1 - Ogale, Abhijit S. A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Handbook of Geometric ComputingHandbook of Geometric Computing PB - Springer Berlin Heidelberg SN - 978-3-540-28247-1 UR - http://dx.doi.org/10.1007/3-540-28247-5_12 ER - TY - CONF T1 - Discovering a language for human activity T2 - Proceedings of the AAAI 2005 Fall Symposium on Anticipatory Cognitive Embodied Systems, Washington, DC Y1 - 2005 A1 - Guerra-Filho,G. A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Proceedings of the AAAI 2005 Fall Symposium on Anticipatory Cognitive Embodied Systems, Washington, DC ER - TY - CONF T1 - Efficient query processing on spatial networks T2 - Proceedings of the 13th annual ACM international workshop on Geographic information systems Y1 - 2005 A1 - Sankaranarayanan,Jagan A1 - Alborzi,Houman A1 - Samet, Hanan KW - location-based services KW - path coherence KW - Query processing KW - SILC framework KW - Spatial databases KW - spatial networks AB - A framework for determining the shortest path and the distance between every pair of vertices on a spatial network is presented. The framework, termed SILC, uses path coherence between the shortest path and the spatial positions of vertices on the spatial network, thereby, resulting in an encoding that is compact in representation and fast in path and distance retrievals. Using this framework, a wide variety of spatial queries such as incremental nearest neighbor searches and spatial distance joins can be shown to work on datasets of locations residing on a spatial network of sufficiently large size. The suggested framework is suitable for both main memory and disk-resident datasets. JA - Proceedings of the 13th annual ACM international workshop on Geographic information systems T3 - GIS '05 PB - ACM CY - New York, NY, USA SN - 1-59593-146-5 UR - http://doi.acm.org/10.1145/1097064.1097093 M3 - 10.1145/1097064.1097093 ER - TY - JOUR T1 - Efficient strategies for channel management in wireless lans JF - UMD, CS Tech. Rep. CS-TR Y1 - 2005 A1 - Mishra,A. A1 - Brik,V. A1 - Banerjee,S. A1 - Srinivasan, Aravind A1 - Arbaugh, William A. AB - We define efficient algorithms for channel management (channelassignment and load balancing among APs) in 802.11-based WLANs that lead to better usage of the wireless spectrum. These algorithms (called CFAssign) are based on a “conflict-free set coloring” for- mulation that jointly perform load balancing along with channel assignment. Such a formulation has a number of advantages. First, it explicitly captures interference effects at clients. Next, it intrinsi- cally exposes opportunities for better channel re-use. Finally, algo- rithms based on this formulation do not depend on specific physical RF models and hence can be applied efficiently to a wide-range of in-building as well as outdoor scenarios. We have performed extensive packet-level simulations and mea- surements on a deployed wireless testbed of 70 APs to validate the performance of our proposed algorithms. We show that in ad- dition to single network scenarios, CFAssign algorithms are well suited for channel assignment in scenarios where multiple wireless networks share the same physical space and contend for the same frequency spectrum. Our results over a wide range of scenarios indicate that CFAssign reduces the interference at clients by about 50-70% in comparison to current best-known techniques. VL - 4729 ER - TY - CONF T1 - Ego-Motion Estimation and 3D Model Refinement in Scenes with Varying Illumination T2 - Application of Computer Vision, 2005. WACV/MOTIONS '05 Volume 1. Seventh IEEE Workshops on Y1 - 2005 A1 - Agrawal,Amit K A1 - Chellapa, Rama AB - We present an iterative algorithm for robustly estimating the ego-motion and refining and updating a coarse depth map using surface parallax and a generalized dynamic image (GDI) model. Given a coarse depth map acquired by a range-finder or extracted from a Digital Elevation Map (DEM), we first estimate the ego-motion by combining a global ego-motion constraint and a local GDI model. Using the estimated camera motion and the available depth estimate, motion of the 3D points is compensated. We utilize the fact that the resulting surface parallax field is an epipolar field and constrain its direction using the previous motion estimates. We then estimate the magnitude of the parallax field and the GDI model parameters locally and use them to refine the depth map estimates. We use a tensor based approach to formulate the depth refinement procedure as an eigen-value problem and obtain confidence measures for determining the accuracy of the estimated depth values. These confidence measures are used to remove regions with potentially incorrect depth estimates for robustly estimating ego-motion in the next iteration. Experimental results using both synthetic and real data are presented. Comparisons with results obtained using a brightness constancy (BC) model show that the proposed algorithm works significantly better when time-varying illumination changes are present in the scene. JA - Application of Computer Vision, 2005. WACV/MOTIONS '05 Volume 1. Seventh IEEE Workshops on VL - 2 M3 - 10.1109/ACVMOT.2005.45 ER - TY - JOUR T1 - EvoSTOC Contributions JF - Applications of evolutionary computing: EvoWorkshops 2005, EvoBIO, EvoCOMNET, EvoHOT, EvoIASP, EvoMUSART, and EvoSTOC Y1 - 2005 A1 - Merkle,D. A1 - Middendorf,M. A1 - Scheidler,A. A1 - Avigad,G. A1 - Moshaiov,A. A1 - Brauner,N. A1 - Parsopoulos,K.E. A1 - Vrahatis,M.N. A1 - Rand, William A1 - Riolo,R ER - TY - CONF T1 - Exploiting partially overlapping channels in wireless networks: Turning a peril into an advantage T2 - Proceedings of the 5th ACM SIGCOMM conference on Internet Measurement Y1 - 2005 A1 - Mishra,A. A1 - Rozner,E. A1 - Banerjee,S. A1 - Arbaugh, William A. JA - Proceedings of the 5th ACM SIGCOMM conference on Internet Measurement ER - TY - CONF T1 - Face recognition in the presence of multiple illumination sources T2 - Computer Vision, 2005. ICCV 2005. Tenth IEEE International Conference on Y1 - 2005 A1 - Aggarwal,G. A1 - Chellapa, Rama KW - approach;estimation KW - illumination KW - Lambert KW - law;analysis-by-synthesis KW - nonlinearity;multiple KW - process;face KW - recognition;hard KW - recognition;light KW - source;face KW - sources; AB - Most existing face recognition algorithms work well for controlled images but are quite susceptible to changes in illumination and pose. This has led to the rise of analysis-by-synthesis approaches due to their inherent potential to handle these external factors. Though these approaches work quite well, most of them assume that the face is illuminated by a single light source which is usually not true in realistic conditions. In this paper, we propose an algorithm to recognize faces illuminated by arbitrarily placed, multiple light sources. The algorithm does not need to know the number of light sources and works extremely well even while recognizing faces illuminated by different number of light sources. Results using this algorithm are reported on multiple-illumination datasets generated from PIE by T. Sim, et al. (2003) and Yale Face Database B by W. Zhao, et al. (2003). We also highlight the importance of the hard non-linearity in the Lambert's law which is often ignored, probably to linearize the estimation process JA - Computer Vision, 2005. ICCV 2005. Tenth IEEE International Conference on VL - 2 M3 - 10.1109/ICCV.2005.92 ER - TY - CHAP T1 - Fault-Tolerant Middleware and the Magical 1% T2 - Middleware 2005 Y1 - 2005 A1 - Tudor Dumitras A1 - Narasimhan, Priya ED - Alonso, Gustavo KW - Computer Communication Networks KW - Information Systems Applications (incl.Internet) KW - Operating systems KW - Programming Languages, Compilers, Interpreters KW - Programming Techniques KW - software engineering AB - Through an extensive experimental analysis of over 900 possible configurations of a fault-tolerant middleware system, we present empirical evidence that the unpredictability inherent in such systems arises from merely 1% of the remote invocations. The occurrence of very high latencies cannot be regulated through parameters such as the number of clients, the replication style and degree or the request rates. However, by selectively filtering out a “magical 1%” of the raw observations of various metrics, we show that performance, in terms of measured end-to-end latency and throughput, can be bounded, easy to understand and control. This simple statistical technique enables us to guarantee, with some level of confidence, bounds for percentile-based quality of service (QoS) metrics, which dramatically increase our ability to tune and control a middleware system in a predictable manner. JA - Middleware 2005 T3 - Lecture Notes in Computer Science PB - Springer Berlin Heidelberg SN - 978-3-540-30323-7, 978-3-540-32269-6 UR - http://link.springer.com/chapter/10.1007/11587552_24 ER - TY - CHAP T1 - Fusing Depth and Video Using Rao-Blackwellized Particle Filter T2 - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence Y1 - 2005 A1 - Agrawal,Amit A1 - Chellapa, Rama ED - Pal,Sankar ED - Bandyopadhyay,Sanghamitra ED - Biswas,Sambhunath AB - We address the problem of fusing sparse and noisy depth data obtained from a range finder with features obtained from intensity images to estimate ego-motion and refine 3D structure of a scene using a Rao-Blackwellized particle filter. For scenes with low depth variability, the algorithm shows an alternate way of performing Structure from Motion (SfM) starting with a flat depth map. Instead of using 3D depths, we formulate the problem using 2D image domain parallax and show that conditioned on non-linear motion parameters, the parallax magnitude with respect to the projection of the vanishing point forms a linear subsystem independent of camera motion and their distributions can be analytically integrated. Thus, the structure is obtained by estimating parallax with respect to the given depths using a Kalman filter and only the ego-motion is estimated using a particle filter. Hence, the required number of particles becomes independent of the number of feature points which is an improvement over previous algorithms. Experimental results on both synthetic and real data show the effectiveness of our approach. JA - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3776 SN - 978-3-540-30506-4 UR - http://dx.doi.org/10.1007/11590316_82 ER - TY - JOUR T1 - Generating and Querying Semantic Web Environments for Photo Libraries (2005) JF - Institute for Systems Research Technical Reports Y1 - 2005 A1 - Axelrod,Adam A1 - Golbeck,Jennifer A1 - Shneiderman, Ben KW - Technical Report AB - Online photo libraries require a method to efficiently search a collection of photographs, and retrieve photos with similar attributes. Our motivation was to incorporate an existing collection of over 250 photographs of over 200 faculty members and events spanning 7 decades into a library called CS PhotoHistory that is available in hypertext and on the Semantic Web. In this paper, we identify challenges related to making this repository available on the Semantic Web, including issues of automation, modeling, and expressivity. Using CS PhotoHistory as a case study, we describe the process of creating an ontology and a querying interface for interacting with a digital photo library on the Semantic Web. UR - http://drum.lib.umd.edu/handle/1903/6538 ER - TY - CONF T1 - Generating testable hypotheses from tacit knowledge for high productivity computing T2 - Proceedings of the second international workshop on Software engineering for high performance computing system applications Y1 - 2005 A1 - Asgari, Sima A1 - Hochstein, Lorin A1 - Basili, Victor R. A1 - Zelkowitz, Marvin V A1 - Hollingsworth, Jeffrey K A1 - Carver, Jeff A1 - Shull, Forrest KW - folklore elicitation KW - high productivity development time experimental studies KW - hypothesis generation KW - tacit knowledge solicitation KW - testable hypotheses AB - In this research, we are developing our understanding of how the high performance computing community develops effective parallel implementations of programs by collecting the folklore within the community. We use this folklore as the basis for a series of experiments, which we expect, will validate or negate these assumptions. JA - Proceedings of the second international workshop on Software engineering for high performance computing system applications T3 - SE-HPCS '05 PB - ACM CY - New York, NY, USA SN - 1-59593-117-1 UR - http://doi.acm.org/10.1145/1145319.1145325 M3 - 10.1145/1145319.1145325 ER - TY - JOUR T1 - The genome of the protist parasite Entamoeba histolytica JF - Nature Y1 - 2005 A1 - Loftus,B. A1 - Anderson,I. A1 - Davies,R. A1 - Alsmark,U. C.M A1 - Samuelson,J. A1 - Amedeo,P. A1 - Roncaglia,P. A1 - Berriman,M. A1 - Hirt,R. P A1 - Mann,B. J A1 - others VL - 433 CP - 7028 ER - TY - JOUR T1 - The genome sequence of Trypanosoma cruzi, etiologic agent of Chagas disease JF - Science Y1 - 2005 A1 - El-Sayed, N.M. A1 - Myler,P. J A1 - Bartholomeu,D. C A1 - Nilsson,D. A1 - Aggarwal,G. A1 - Tran,A. N A1 - Ghedin,E. A1 - Worthey,E. A A1 - Delcher,A. L A1 - Blandin,G. A1 - others VL - 309 CP - 5733 ER - TY - JOUR T1 - The Genome Sequence of Trypanosoma Cruzi, Etiologic Agent of Chagas Disease JF - ScienceScience Y1 - 2005 A1 - El‐Sayed, Najib M. A1 - Myler,Peter J. A1 - Bartholomeu,Daniella C. A1 - Nilsson,Daniel A1 - Aggarwal,Gautam A1 - Tran,Anh-Nhi A1 - Ghedin,Elodie A1 - Worthey,Elizabeth A. A1 - Delcher,Arthur L. A1 - Blandin,Gaëlle A1 - Westenberger,Scott J. A1 - Caler,Elisabet A1 - Cerqueira,Gustavo C. A1 - Branche,Carole A1 - Haas,Brian A1 - Anupama,Atashi A1 - Arner,Erik A1 - Åslund,Lena A1 - Attipoe,Philip A1 - Bontempi,Esteban A1 - Bringaud,Frédéric A1 - Burton,Peter A1 - Cadag,Eithon A1 - Campbell,David A. A1 - Carrington,Mark A1 - Crabtree,Jonathan A1 - Darban,Hamid A1 - da Silveira,Jose Franco A1 - de Jong,Pieter A1 - Edwards,Kimberly A1 - Englund,Paul T. A1 - Fazelina,Gholam A1 - Feldblyum,Tamara A1 - Ferella,Marcela A1 - Frasch,Alberto Carlos A1 - Gull,Keith A1 - Horn,David A1 - Hou,Lihua A1 - Huang,Yiting A1 - Kindlund,Ellen A1 - Klingbeil,Michele A1 - Kluge,Sindy A1 - Koo,Hean A1 - Lacerda,Daniela A1 - Levin,Mariano J. A1 - Lorenzi,Hernan A1 - Louie,Tin A1 - Machado,Carlos Renato A1 - McCulloch,Richard A1 - McKenna,Alan A1 - Mizuno,Yumi A1 - Mottram,Jeremy C. A1 - Nelson,Siri A1 - Ochaya,Stephen A1 - Osoegawa,Kazutoyo A1 - Pai,Grace A1 - Parsons,Marilyn A1 - Pentony,Martin A1 - Pettersson,Ulf A1 - Pop, Mihai A1 - Ramirez,Jose Luis A1 - Rinta,Joel A1 - Robertson,Laura A1 - Salzberg,Steven L. A1 - Sanchez,Daniel O. A1 - Seyler,Amber A1 - Sharma,Reuben A1 - Shetty,Jyoti A1 - Simpson,Anjana J. A1 - Sisk,Ellen A1 - Tammi,Martti T. A1 - Tarleton,Rick A1 - Teixeira,Santuza A1 - Van Aken,Susan A1 - Vogt,Christy A1 - Ward,Pauline N. A1 - Wickstead,Bill A1 - Wortman,Jennifer A1 - White,Owen A1 - Fraser,Claire M. A1 - Stuart,Kenneth D. A1 - Andersson,Björn AB - Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention. VL - 309 SN - 0036-8075, 1095-9203 UR - http://www.sciencemag.org/content/309/5733/409 CP - 5733 M3 - 10.1126/science.1112631 ER - TY - JOUR T1 - The Genome Sequence of Trypanosoma cruzi, Etiologic Agent of Chagas Disease JF - Science Y1 - 2005 A1 - El‐Sayed, Najib M. A1 - Myler,Peter J. A1 - Bartholomeu,Daniella C. A1 - Nilsson,Daniel A1 - Aggarwal,Gautam A1 - Tran,Anh-Nhi A1 - Ghedin,Elodie A1 - Worthey,Elizabeth A. A1 - Delcher,Arthur L. A1 - Blandin,Gaëlle A1 - Westenberger,Scott J. A1 - Caler,Elisabet A1 - Cerqueira,Gustavo C. A1 - Branche,Carole A1 - Haas,Brian A1 - Anupama,Atashi A1 - Arner,Erik A1 - Åslund,Lena A1 - Attipoe,Philip A1 - Bontempi,Esteban A1 - Bringaud,Frédéric A1 - Burton,Peter A1 - Cadag,Eithon A1 - Campbell,David A. A1 - Carrington,Mark A1 - Crabtree,Jonathan A1 - Darban,Hamid A1 - da Silveira,Jose Franco A1 - de Jong,Pieter A1 - Edwards,Kimberly A1 - Englund,Paul T. A1 - Fazelina,Gholam A1 - Feldblyum,Tamara A1 - Ferella,Marcela A1 - Frasch,Alberto Carlos A1 - Gull,Keith A1 - Horn,David A1 - Hou,Lihua A1 - Huang,Yiting A1 - Kindlund,Ellen A1 - Klingbeil,Michele A1 - Kluge,Sindy A1 - Koo,Hean A1 - Lacerda,Daniela A1 - Levin,Mariano J. A1 - Lorenzi,Hernan A1 - Louie,Tin A1 - Machado,Carlos Renato A1 - McCulloch,Richard A1 - McKenna,Alan A1 - Mizuno,Yumi A1 - Mottram,Jeremy C. A1 - Nelson,Siri A1 - Ochaya,Stephen A1 - Osoegawa,Kazutoyo A1 - Pai,Grace A1 - Parsons,Marilyn A1 - Pentony,Martin A1 - Pettersson,Ulf A1 - Pop, Mihai A1 - Ramirez,Jose Luis A1 - Rinta,Joel A1 - Robertson,Laura A1 - Salzberg,Steven L. A1 - Sanchez,Daniel O. A1 - Seyler,Amber A1 - Sharma,Reuben A1 - Shetty,Jyoti A1 - Simpson,Anjana J. A1 - Sisk,Ellen A1 - Tammi,Martti T. A1 - Tarleton,Rick A1 - Teixeira,Santuza A1 - Van Aken,Susan A1 - Vogt,Christy A1 - Ward,Pauline N. A1 - Wickstead,Bill A1 - Wortman,Jennifer A1 - White,Owen A1 - Fraser,Claire M. A1 - Stuart,Kenneth D. A1 - Andersson,Björn AB - Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention. VL - 309 UR - http://www.sciencemag.org/content/309/5733/409.abstract CP - 5733 M3 - 10.1126/science.1112631 ER - TY - CONF T1 - Identifying and segmenting human-motion for mobile robot navigation using alignment errors T2 - 12th International Conference on Advanced Robotics, 2005. ICAR '05. Proceedings Y1 - 2005 A1 - Abd-Almageed, Wael A1 - Burns,B. J A1 - Davis, Larry S. KW - Computer errors KW - Educational institutions KW - Frequency estimation KW - human-motion identification KW - human-motion segmentation KW - HUMANS KW - Image motion analysis KW - Image segmentation KW - mobile robot navigation KW - Mobile robots KW - Motion estimation KW - Navigation KW - Object detection KW - robot vision KW - SHAPE AB - This paper presents a new human-motion identification and segmentation algorithm, for mobile robot platforms. The algorithm is based on computing the alignment error between pairs of object images acquired from a moving platform. Pairs of images generating relatively small alignment errors are used to estimate the fundamental frequency of the object's motion. A decision criterion is then used to test the significance of the estimated frequency and to classify the object's motion. To verify the validity of the proposed approach, experimental results are shown on different classes of objects JA - 12th International Conference on Advanced Robotics, 2005. ICAR '05. Proceedings PB - IEEE SN - 0-7803-9178-0 M3 - 10.1109/ICAR.2005.1507441 ER - TY - CHAP T1 - Image Sequence Stabilization, Mosaicking, and Superresolution T2 - Handbook of Image and Video Processing (Second Edition)Handbook of Image and Video Processing (Second Edition) Y1 - 2005 A1 - Chellapa, Rama A1 - Srinivasan, S. A1 - Aggarwal,G. A1 - Veeraraghavan,A. ED - Al Bovik AB - A sequence of temporal images gathered from a single sensor adds a whole new dimension to two-dimensional (2D) image data. Availability of an image sequence permits the measurement of quantities such as subpixel intensities, camera motion and depth, and detection and tracking of moving objects. In turn, the processing of image sequences necessitates the development of sophisticated techniques to extract this information. With the recent availability of powerful yet inexpensive computers, data storage systems, and image acquisition devices, image sequence analysis has transitioned from an esoteric research domain to a practical area with significant commercial interest. JA - Handbook of Image and Video Processing (Second Edition)Handbook of Image and Video Processing (Second Edition) PB - Academic Press CY - Burlington SN - 978-0-12-119792-6 UR - http://www.sciencedirect.com/science/article/pii/B9780121197926500826 ER - TY - CHAP T1 - Information Visualization and the Challenge of Universal Usability T2 - Exploring GeovisualizationExploring Geovisualization Y1 - 2005 A1 - Plaisant, Catherine ED - Jason Dykes ED - Alan M. MacEachren and Menno-Jan KraakA2 - Jason Dykes,Alan M. MacEachren ED - Menno-Jan Kraak AB - Information Visualization aims to provide compact graphical presentations and user interfaces for interactively manipulating large numbers of items. We present a simple “data by tasks taxonomy” then discuss the challenges of providing universal usability, with example applications using geo-referenced data. Information Visualization has been shown to be a powerful visual thinking or decision tool but it is becoming important for services to reach and empower every citizen. Technological advances are needed to deal with user diversity (age, language, disabilities, etc.) but also with the variety of technology used (screen size, network speed, etc.) and the gaps in user's knowledge (general knowledge, knowledge of the application domain, of the interface syntax or semantic). We present examples that illustrate how those challenges can be addressed. JA - Exploring GeovisualizationExploring Geovisualization PB - Elsevier CY - Oxford SN - 978-0-08-044531-1 UR - http://www.sciencedirect.com/science/article/pii/B9780080445311504218 ER - TY - JOUR T1 - Interactive pattern search in time series JF - Proceedings of SPIE Y1 - 2005 A1 - Buono,Paolo A1 - Aris,Aleks A1 - Plaisant, Catherine A1 - Khella,Amir A1 - Shneiderman, Ben AB - The need for pattern discovery in long time series data led researchers to develop algorithms for similarity search. Most of the literature about time series focuses on algorithms that index time series and bring the data into the main storage, thus providing fast information retrieval on large time series. This paper reviews the state of the art in visualizing time series, and focuses on techniques that enable users to visually and interactively query time series. Then, it presents TimeSearcher 2, a tool that enables users to explore multidimensional data using synchronized tables and graphs with overview+detail, filter the time series data to reduce the scope of the search, select an existing pattern to find similar occurrences, and interactively adjust similarity parameters to narrow the result set. This tool is an extension of previous work, TimeSearcher 1, which uses graphical timeboxes to interactively query time series data. VL - 5669 SN - 0277786X UR - http://spiedigitallibrary.org/proceedings/resource/2/psisdg/5669/1/175_1?isAuthorized=no CP - 1 M3 - doi:10.1117/12.587537 ER - TY - RPRT T1 - Interactive Pattern Search in Time Series (2004) Y1 - 2005 A1 - Buono,Paolo A1 - Aris,Aleks A1 - Plaisant, Catherine A1 - Khella,Amir A1 - Shneiderman, Ben KW - Technical Report AB - The need for pattern discovery in long time series data led researchers to develop algorithms for similarity search. Most of the literature about time series focuses on algorithms that index time series and bring the data into the main storage, thus providing fast information retrieval on large time series. This paper reviews the state of the art in visualizing time series, and focuses on techniques that enable users to interactively query time series. Then it presents TimeSearcher 2, a tool that enables users to explore multidimensional data using coordinated tables and graphs with overview+detail, filter the time series data to reduce the scope of the search, select an existing pattern to find similar occurrences, and interactively adjust similarity parameters to narrow the result set. This tool is an extension of previous work, TimeSearcher 1, which uses graphical timeboxes to interactively query time series data. JA - Institute for Systems Research Technical Reports UR - http://drum.lib.umd.edu/handle/1903/6519 ER - TY - CONF T1 - The Java memory model T2 - Proceedings of the 32nd ACM SIGPLAN-SIGACT symposium on Principles of programming languages Y1 - 2005 A1 - Manson,Jeremy A1 - Pugh, William A1 - Adve,Sarita V. KW - concurrency KW - java KW - memory model KW - Multithreading AB - This paper describes the new Java memory model, which has been revised as part of Java 5.0. The model specifies the legal behaviors for a multithreaded program; it defines the semantics of multithreaded Java programs and partially determines legal implementations of Java virtual machines and compilers.The new Java model provides a simple interface for correctly synchronized programs -- it guarantees sequential consistency to data-race-free programs. Its novel contribution is requiring that the behavior of incorrectly synchronized programs be bounded by a well defined notion of causality. The causality requirement is strong enough to respect the safety and security properties of Java and weak enough to allow standard compiler and hardware optimizations. To our knowledge, other models are either too weak because they do not provide for sufficient safety/security, or are too strong because they rely on a strong notion of data and control dependences that precludes some standard compiler transformations.Although the majority of what is currently done in compilers is legal, the new model introduces significant differences, and clearly defines the boundaries of legal transformations. For example, the commonly accepted definition for control dependence is incorrect for Java, and transformations based on it may be invalid.In addition to providing the official memory model for Java, we believe the model described here could prove to be a useful basis for other programming languages that currently lack well-defined models, such as C++ and C#. JA - Proceedings of the 32nd ACM SIGPLAN-SIGACT symposium on Principles of programming languages T3 - POPL '05 PB - ACM CY - New York, NY, USA SN - 1-58113-830-X UR - http://doi.acm.org/10.1145/1040305.1040336 M3 - 10.1145/1040305.1040336 ER - TY - CONF T1 - Learning approximate preconditions for methods in hierarchical plans Y1 - 2005 A1 - Ilghami,Okhtay A1 - Muñoz-Avila,Héctor A1 - Nau, Dana S. A1 - Aha,David W. AB - A significant challenge in developing planning systems for practical applications is the difficulty of acquiring the domain knowledge needed by such systems. One method for acquiring this knowledge is to learn it from plan traces, but this method typically requires a huge number of plan traces to converge. In this paper, we show that the problem with slow convergence can be circumvented by having the learner generate solution plans even before the planning domain is completely learned. Our empirical results show that these improvements reduce the size of the training set that is needed to find correct answers to a large percentage of planning problems in the test set. T3 - ICML '05 PB - ACM CY - New York, NY, USA SN - 1-59593-180-5 UR - http://doi.acm.org/10.1145/1102351.1102394 M3 - 10.1145/1102351.1102394 ER - TY - CONF T1 - A learning automata based power management for ad-hoc networks T2 - 2005 IEEE International Conference on Systems, Man and Cybernetics Y1 - 2005 A1 - El-Osery,A. I A1 - Baird,D. A1 - Abd-Almageed, Wael KW - ad hoc networks KW - ad-hoc networks KW - Computer network management KW - Computer networks KW - Energy management KW - Engineering management KW - learning automata KW - network metrics KW - network simulator KW - packet retransmissions KW - power control KW - power system management KW - power transmission control KW - stochastic learning automata KW - stochastic learning automta KW - Stochastic processes KW - system bandwidth KW - Technology management KW - Throughput KW - transmission power control KW - transmission power level KW - transmission power management AB - Power management is a very important aspect of ad-hoc networks. It directly impacts the network throughput among other network metrics. On the other hand, transmission power management may result in disconnected networks and increased level of collisions. In this paper, we introduce a transmission power control based on stochastic learning automata (SLA) to modify the transmission power. Based on the level of successful transmissions and the level of packet retransmissions, the SLA will modify the transmission power level either by increasing it or decreasing it. The probabilistic nature of SLA makes it a useful choice for ad-hoc networks. Using the network simulator NS, we show that using SLA for transmission power will result in an increased system bandwidth and a decrease in the collision levels. JA - 2005 IEEE International Conference on Systems, Man and Cybernetics PB - IEEE VL - 4 SN - 0-7803-9298-1 M3 - 10.1109/ICSMC.2005.1571701 ER - TY - JOUR T1 - Learning preconditions for planning from plan traces and HTN structure JF - Computational Intelligence Y1 - 2005 A1 - Ilghami,Okhtay A1 - Nau, Dana S. A1 - Muñoz-Avila,Héctor A1 - Aha,David W. KW - candidate elimination KW - HTN planning KW - learning KW - version spaces AB - A great challenge in developing planning systems for practical applications is the difficulty of acquiring the domain information needed to guide such systems. This paper describes a way to learn some of that knowledge. More specifically, the following points are discussed. (1) We introduce a theoretical basis for formally defining algorithms that learn preconditions for Hierarchical Task Network (HTN) methods. (2) We describe Candidate Elimination Method Learner (CaMeL), a supervised, eager, and incremental learning process for preconditions of HTN methods. We state and prove theorems about CaMeL's soundness, completeness, and convergence properties. (3) We present empirical results about CaMeL's convergence under various conditions. Among other things, CaMeL converges the fastest on the preconditions of the HTN methods that are needed the most often. Thus CaMeL's output can be useful even before it has fully converged. VL - 21 SN - 1467-8640 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8640.2005.00279.x/abstract CP - 4 M3 - 10.1111/j.1467-8640.2005.00279.x ER - TY - JOUR T1 - Logic, self-awareness and self-improvement: The metacognitive loop and the problem of brittleness JF - Journal of Logic and Computation Y1 - 2005 A1 - Anderson,M. L A1 - Perlis, Don VL - 15 CP - 1 ER - TY - JOUR T1 - Matching shape sequences in video with applications in human movement analysis JF - Pattern Analysis and Machine Intelligence, IEEE Transactions on Y1 - 2005 A1 - A,Veeraraghavan A1 - Roy-Chowdhury, A.K. A1 - Chellapa, Rama KW - Automated;Photography;Reproducibility of Results;Sensitivity and Specificity;Subtraction Technique;Video Recording; KW - autoregressive moving average model;deforming shapes;dynamic time-warping;feature extraction;gait-based human recognition;human movement analysis;matching shape sequences;video;autoregressive moving average processes;feature extraction;image matching;imag KW - Biological;Models KW - Computer-Assisted;Imaging KW - Statistical;Movement;Pattern Recognition KW - Three-Dimensional;Leg;Models AB - We present an approach for comparing two sequences of deforming shapes using both parametric models and nonparametric methods. In our approach, Kendall's definition of shape is used for feature extraction. Since the shape feature rests on a non-Euclidean manifold, we propose parametric models like the autoregressive model and autoregressive moving average model on the tangent space and demonstrate the ability of these models to capture the nature of shape deformations using experiments on gait-based human recognition. The nonparametric model is based on dynamic time-warping. We suggest a modification of the dynamic time-warping algorithm to include the nature of the non-Euclidean space in which the shape deformations take place. We also show the efficacy of this algorithm by its application to gait-based human recognition. We exploit the shape deformations of a person's silhouette as a discriminating feature and provide recognition results using the nonparametric model. Our analysis leads to some interesting observations on the role of shape and kinematics in automated gait-based person authentication. VL - 27 SN - 0162-8828 CP - 12 M3 - 10.1109/TPAMI.2005.246 ER - TY - CONF T1 - Measuring productivity on high performance computers T2 - 11th IEEE International Symposium on Software Metric Y1 - 2005 A1 - Zelkowitz, Marvin V A1 - Basili, Victor R. A1 - Asgari, S. A1 - Hochstein, L. A1 - Hollingsworth, Jeffrey K A1 - Nakamura, T. AB - In the high performance computing domain, the speed ofexecution of a program has typically been the primary performance metric. But productivity is also of concern to high performance computing developers. In this paper we will discuss the problems of defining and measuring productivity for these machines and we develop a model of productivity that includes both a performance component and a component that measures the development time of the program. We ran several experiments using students in high performance courses at several universities, and we report on those results with respect to our model of productivity. JA - 11th IEEE International Symposium on Software Metric ER - TY - CONF T1 - Metacognition for dropping and reconsidering intentions T2 - AAAI Spring Symposium on Metacognition in Computation Y1 - 2005 A1 - Josyula,D. P A1 - Anderson,M. L A1 - Perlis, Don JA - AAAI Spring Symposium on Metacognition in Computation ER - TY - PAT T1 - Method and system for providing physical security in an area of interest Y1 - 2005 A1 - Agrawala, Ashok K. A1 - Youssef,Moustafa Amin A1 - Shahamat,Layla AB - A system for detecting the presence of an intruder in a protected area utilizes a received signal strength indicator (RSSI) value of signals broadcast from transmitting stations deployed in the protected area. The system includes monitoring points for receiving broadcast signals, measuring the RSSI values of the received signals, and transmitting the measured RSSI values to a security system server. The security system server analyzes the RSSI values, and initiates security measures when the physical security of the protected area is violated which is detected when the measured RSSI values deviate from a predetermined strength of the broadcast signals. The security system also has the ability to track objects in the protected area and keep track of their movement in real time and report such movement. The system may be based on a Wi-Fi infrastructure in the protected area. VL - 10/916,545 UR - http://www.google.com/patents?id=VIaWAAAAEBAJ ER - TY - JOUR T1 - Motion segmentation using occlusions JF - IEEE Transactions on Pattern Analysis and Machine Intelligence Y1 - 2005 A1 - Ogale, A. S A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion estimation KW - algorithms KW - Artificial intelligence KW - CAMERAS KW - Computer vision KW - Filling KW - hidden feature removal KW - Image Enhancement KW - Image Interpretation, Computer-Assisted KW - image motion KW - Image motion analysis KW - Image segmentation KW - Layout KW - MOTION KW - Motion detection KW - Motion estimation KW - motion segmentation KW - Movement KW - Object detection KW - occlusion KW - occlusions KW - optical flow KW - ordinal depth KW - Pattern Recognition, Automated KW - Photography KW - Reproducibility of results KW - segmentation KW - Semiconductor device modeling KW - Sensitivity and Specificity KW - video analysis. KW - Video Recording AB - We examine the key role of occlusions in finding independently moving objects instantaneously in a video obtained by a moving camera with a restricted field of view. In this problem, the image motion is caused by the combined effect of camera motion (egomotion), structure (depth), and the independent motion of scene entities. For a camera with a restricted field of view undergoing a small motion between frames, there exists, in general, a set of 3D camera motions compatible with the observed flow field even if only a small amount of noise is present, leading to ambiguous 3D motion estimates. If separable sets of solutions exist, motion-based clustering can detect one category of moving objects. Even if a single inseparable set of solutions is found, we show that occlusion information can be used to find ordinal depth, which is critical in identifying a new class of moving objects. In order to find ordinal depth, occlusions must not only be known, but they must also be filled (grouped) with optical flow from neighboring regions. We present a novel algorithm for filling occlusions and deducing ordinal depth under general circumstances. Finally, we describe another category of moving objects which is detected using cardinal comparisons between structure from motion and structure estimates from another source (e.g., stereo). VL - 27 SN - 0162-8828 CP - 6 M3 - 10.1109/TPAMI.2005.123 ER - TY - CHAP T1 - Moving Object Detection and Compression in IR Sequences T2 - Computer Vision Beyond the Visible SpectrumComputer Vision Beyond the Visible Spectrum Y1 - 2005 A1 - Vaswani,Namrata A1 - Agrawal,Amit A1 - Qinfen Zheng A1 - Chellapa, Rama ED - Bhanu,Bir ED - Pavlidis,Ioannis AB - We consider the problem of remote surveillance using infrared (IR) sensors. The aim is to use IR image sequences to detect moving objects (humans or vehicles), and to transmit a few “best-view images” of every new object that is detected. Since the available bandwidth is usually low, if the object chip is big, it needs to be compressed before being transmitted. Due to low computational power of computing devices attached to the sensor, the algorithms should be computationally simple. We present two approaches for object detection — one which specifically solves the more difficult long-range object detection problem, and the other for objects at short range. For objects at short range, we also present techniques for selecting a single best-view object chip and computationally simple techniques for compressing it to very low bit rates due to the channel bandwidth constraint. A fast image chip compression scheme implemented in the wavelet domain by combining a non-iterative zerotree coding method with 2D-DPCM for both low-and high-frequency subbands is presented. Comparisons with some existing schemes are also included. The object detection and compression algorithms have been implemented in C/C++ and their performance has been evaluated using the Hitachi’s SH4 platform with software simulation. JA - Computer Vision Beyond the Visible SpectrumComputer Vision Beyond the Visible Spectrum T3 - Advances in Pattern Recognition PB - Springer London SN - 978-1-84628-065-8 UR - http://dx.doi.org/10.1007/1-84628-065-6_5 ER - TY - CONF T1 - Moving Object Segmentation and Dynamic Scene Reconstruction Using Two Frames T2 - Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on Y1 - 2005 A1 - Agrawala, Ashok K. A1 - Chellapa, Rama KW - 3D KW - analysis; KW - constraints; KW - dynamic KW - ego-motion KW - estimation; KW - flow KW - image KW - images; KW - independent KW - INTENSITY KW - least KW - mean KW - median KW - method; KW - methods; KW - model; KW - MOTION KW - motion; KW - moving KW - object KW - of KW - parallax KW - parallax; KW - parametric KW - processing; KW - reconstruction; KW - scene KW - segmentation; KW - signal KW - squares KW - squares; KW - static KW - structure; KW - subspace KW - surface KW - translational KW - two-frame KW - unconstrained KW - video JA - Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on VL - 2 M3 - 10.1109/ICASSP.2005.1415502 ER - TY - CONF T1 - NeurAlign: combining word alignments using neural networks T2 - Proceedings of the conference on Human Language Technology and Empirical Methods in Natural Language Processing Y1 - 2005 A1 - Ayan,Necip Fazil A1 - Dorr, Bonnie J A1 - Monz,Christof AB - This paper presents a novel approach to combining different word alignments. We view word alignment as a pattern classification problem, where alignment combination is treated as a classifier ensemble, and alignment links are adorned with linguistic features. A neural network model is used to learn word alignments from the individual alignment systems. We show that our alignment combination approach yields a significant 20--34% relative error reduction over the best-known alignment combination technique on English-Spanish and English-Chinese data. JA - Proceedings of the conference on Human Language Technology and Empirical Methods in Natural Language Processing T3 - HLT '05 PB - Association for Computational Linguistics CY - Stroudsburg, PA, USA UR - http://dx.doi.org/10.3115/1220575.1220584 M3 - 10.3115/1220575.1220584 ER - TY - CHAP T1 - Pattern Recognition in Video T2 - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence Y1 - 2005 A1 - Chellapa, Rama A1 - Veeraraghavan,Ashok A1 - Aggarwal,Gaurav ED - Pal,Sankar ED - Bandyopadhyay,Sanghamitra ED - Biswas,Sambhunath AB - Images constitute data that live in a very high dimensional space, typically of the order of hundred thousand dimensions. Drawing inferences from correlated data of such high dimensions often becomes intractable. Therefore traditionally several of these problems like face recognition, object recognition, scene understanding etc. have been approached using techniques in pattern recognition. Such methods in conjunction with methods for dimensionality reduction have been highly popular and successful in tackling several image processing tasks. Of late, the advent of cheap, high quality video cameras has generated new interests in extending still image-based recognition methodologies to video sequences. The added temporal dimension in these videos makes problems like face and gait-based human recognition, event detection, activity recognition addressable. Our research has focussed on solving several of these problems through a pattern recognition approach. Of course, in video streams patterns refer to both patterns in the spatial structure of image intensities around interest points and temporal patterns that arise either due to camera motion or object motion. In this paper, we discuss the applications of pattern recognition in video to problems like face and gait-based human recognition, behavior classification, activity recognition and activity based person identification. JA - Pattern Recognition and Machine IntelligencePattern Recognition and Machine Intelligence T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3776 SN - 978-3-540-30506-4 UR - http://dx.doi.org/10.1007/11590316_2 ER - TY - CONF T1 - Pedestrian classification from moving platforms using cyclic motion pattern T2 - Image Processing, 2005. ICIP 2005. IEEE International Conference on Y1 - 2005 A1 - Yang Ran A1 - Qinfen Zheng A1 - Weiss, I. A1 - Davis, Larry S. A1 - Abd-Almageed, Wael A1 - Liang Zhao KW - analysis; KW - angle; KW - body KW - classification; KW - compact KW - cyclic KW - DETECTION KW - detection; KW - digital KW - Feedback KW - Gait KW - human KW - image KW - information; KW - locked KW - loop KW - loop; KW - loops; KW - module; KW - MOTION KW - object KW - oscillations; KW - pattern; KW - pedestrian KW - phase KW - Pixel KW - principle KW - representation; KW - sequence; KW - sequences; KW - SHAPE KW - system; AB - This paper describes an efficient pedestrian detection system for videos acquired from moving platforms. Given a detected and tracked object as a sequence of images within a bounding box, we describe the periodic signature of its motion pattern using a twin-pendulum model. Then a principle gait angle is extracted in every frame providing gait phase information. By estimating the periodicity from the phase data using a digital phase locked loop (dPLL), we quantify the cyclic pattern of the object, which helps us to continuously classify it as a pedestrian. Past approaches have used shape detectors applied to a single image or classifiers based on human body pixel oscillations, but ours is the first to integrate a global cyclic motion model and periodicity analysis. Novel contributions of this paper include: i) development of a compact shape representation of cyclic motion as a signature for a pedestrian, ii) estimation of gait period via a feedback loop module, and iii) implementation of a fast online pedestrian classification system which operates on videos acquired from moving platforms. JA - Image Processing, 2005. ICIP 2005. IEEE International Conference on VL - 2 M3 - 10.1109/ICIP.2005.1530190 ER - TY - CONF T1 - Pedestrian classification from moving platforms using cyclic motion pattern T2 - IEEE International Conference on Image Processing, 2005. ICIP 2005 Y1 - 2005 A1 - Yang Ran A1 - Qinfen Zheng A1 - Weiss, I. A1 - Davis, Larry S. A1 - Abd-Almageed, Wael A1 - Liang Zhao KW - compact shape representation KW - cyclic motion pattern KW - data mining KW - Detectors KW - digital phase locked loop KW - digital phase locked loops KW - feedback loop module KW - gait analysis KW - gait phase information KW - human body pixel oscillations KW - HUMANS KW - image classification KW - Image motion analysis KW - image representation KW - image sequence KW - Image sequences KW - Motion detection KW - Object detection KW - pedestrian classification KW - pedestrian detection system KW - Phase estimation KW - Phase locked loops KW - principle gait angle KW - SHAPE KW - tracking KW - Videos AB - This paper describes an efficient pedestrian detection system for videos acquired from moving platforms. Given a detected and tracked object as a sequence of images within a bounding box, we describe the periodic signature of its motion pattern using a twin-pendulum model. Then a principle gait angle is extracted in every frame providing gait phase information. By estimating the periodicity from the phase data using a digital phase locked loop (dPLL), we quantify the cyclic pattern of the object, which helps us to continuously classify it as a pedestrian. Past approaches have used shape detectors applied to a single image or classifiers based on human body pixel oscillations, but ours is the first to integrate a global cyclic motion model and periodicity analysis. Novel contributions of this paper include: i) development of a compact shape representation of cyclic motion as a signature for a pedestrian, ii) estimation of gait period via a feedback loop module, and iii) implementation of a fast online pedestrian classification system which operates on videos acquired from moving platforms. JA - IEEE International Conference on Image Processing, 2005. ICIP 2005 PB - IEEE VL - 2 SN - 0-7803-9134-9 M3 - 10.1109/ICIP.2005.1530190 ER - TY - CONF T1 - Query planning for the grid: adapting to dynamic resource availability T2 - Cluster Computing and the Grid, IEEE International Symposium on Y1 - 2005 A1 - Zhang,K. A1 - Andrade,H. A1 - Raschid, Louiqa A1 - Sussman, Alan AB - The availability of massive datasets, comprising sensor measurements or the results of scientific simulations, has had a significant impact on the methodology of scientific reasoning. Scientists require storage, bandwidth and computational capacity to query and analyze these datasets, to understand physical phenomena or to test hypotheses. This paper addresses the challenge of identifying and selecting resources to develop an evaluation plan for large scale data analysis queries when data processing capabilities and datasets are dispersed across nodes in one or more computing and storage clusters. We show that generating an optimal plan is hard and we propose heuristic techniques to find a good choice of resources. We also consider heuristics to cope with dynamic resource availability; in this situation we have stale information about reusable cached results (datasets) and the load on various nodes. JA - Cluster Computing and the Grid, IEEE International Symposium on PB - IEEE Computer Society CY - Los Alamitos, CA, USA VL - 2 SN - 0-7803-9074-1 M3 - http://doi.ieeecomputersociety.org/10.1109/CCGRID.2005.1558638 ER - TY - CONF T1 - On the reasoning of real-world agents: Toward a semantics for active logic T2 - 7-th Annual Symposium on the Logical Formalization of Commonsense Reasoning Y1 - 2005 A1 - Anderson,M. L A1 - Gomaa,W. A1 - Grant,J. A1 - Perlis, Don JA - 7-th Annual Symposium on the Logical Formalization of Commonsense Reasoning ER - TY - CHAP T1 - Representing Unevenly-Spaced Time Series Data for Visualization and Interactive Exploration T2 - Human-Computer Interaction - INTERACT 2005Human-Computer Interaction - INTERACT 2005 Y1 - 2005 A1 - Aris,Aleks A1 - Shneiderman, Ben A1 - Plaisant, Catherine A1 - Shmueli,Galit A1 - Jank,Wolfgang ED - Costabile,Maria ED - Paternò,Fabio AB - Visualizing time series is useful to support discovery of relations and patterns in financial, genomic, medical and other applications. Often, measurements are equally spaced over time. We discuss the challenges of unevenly-spaced time series and present fourrepresentationmethods: sampled events, aggregated sampled events, event index and interleaved event index. We developed these methods while studying eBay auction data with TimeSearcher. We describe the advantages, disadvantages, choices for algorithms and parameters, and compare the different methods for different tasks. Interaction issues such as screen resolution, response time for dynamic queries, and learnability are governed by these decisions. JA - Human-Computer Interaction - INTERACT 2005Human-Computer Interaction - INTERACT 2005 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3585 SN - 978-3-540-28943-2 UR - http://dx.doi.org/10.1007/11555261_66 ER - TY - JOUR T1 - Representing Unevenly-Spaced Time Series Data for Visualization and Interactive Exploration (2005) JF - Institute for Systems Research Technical Reports Y1 - 2005 A1 - Aris,Aleks A1 - Shneiderman, Ben A1 - Plaisant, Catherine A1 - Shmueli,Galit A1 - Jank,Wolfgang KW - Technical Report AB - Visualizing time series data is useful to support discovery of relations and patterns in financial, genomic, medical and other applications. In most time series, measurements are equally spaced over time. This paper discusses the challenges for unevenly-spaced time series data and presents four methods to represent them: sampled events, aggregated sampled events, event index and interleaved event index. We developed these methods while studying eBay auction data with TimeSearcher. We describe the advantages, disadvantages, choices for algorithms and parameters, and compare the different methods. Since each method has its advantages, this paper provides guidance for choosing the right combination of methods, algorithms, and parameters to solve a given problem for unevenly-spaced time series. Interaction issues such as screen resolution, response time for dynamic queries, and meaning of the visual display are governed by these decisions. UR - http://drum.lib.umd.edu/handle/1903/6537 ER - TY - CONF T1 - Robust Contrast Invariant Stereo Correspondence T2 - Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 2005. ICRA 2005 Y1 - 2005 A1 - Ogale, A. S A1 - Aloimonos, J. KW - Apertures KW - Calibration KW - CAMERAS KW - Computer science KW - contrast invariance KW - diffusion KW - Educational institutions KW - Frequency KW - gabor KW - Hardware KW - occlusions KW - Robot vision systems KW - Robotics and automation KW - Robustness KW - stereo AB - A stereo pair of cameras attached to a robot will inevitably yield images with different contrast. Even if we assume that the camera hardware is identical, due to slightly different points of view, the amount of light entering the two cameras is also different, causing dynamically adjusted internal parameters such as aperture, exposure and gain to be different. Due to the difficulty of obtaining and maintaining precise intensity or color calibration between the two cameras, contrast invariance becomes an extremely desirable property of stereo correspondence algorithms. The problem of achieving point correspondence between a stereo pair of images is often addressed by using the intensity or color differences as a local matching metric, which is sensitive to contrast changes. We present an algorithm for contrast invariant stereo matching which relies on multiple spatial frequency channels for local matching. A fast global framework uses the local matching to compute the correspondences and find the occlusions. We demonstrate that the use of multiple frequency channels allows the algorithm to yield good results even in the presence of significant amounts of noise. JA - Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 2005. ICRA 2005 PB - IEEE SN - 0-7803-8914-X M3 - 10.1109/ROBOT.2005.1570218 ER - TY - JOUR T1 - Robust routing in malicious environment for ad hoc networks JF - Information Security Practice and Experience Y1 - 2005 A1 - Yu,Z. A1 - Seng,C. Y A1 - Jiang,T. A1 - Wu,X. A1 - Arbaugh, William A. ER - TY - JOUR T1 - ROMER: resilient opportunistic mesh routing for wireless mesh networks JF - Proc. of IEEE WiMesh Y1 - 2005 A1 - Yuan,Y. A1 - Yang,H. A1 - Wong,S. H.Y A1 - Lu,S. A1 - Arbaugh, William A. VL - 166 ER - TY - JOUR T1 - The roots of self-awareness JF - Phenomenology and the Cognitive Sciences Y1 - 2005 A1 - Anderson,M. L A1 - Perlis, Don VL - 4 CP - 3 ER - TY - JOUR T1 - Shape and the stereo correspondence problem JF - International Journal of Computer Vision Y1 - 2005 A1 - Ogale, A. S A1 - Aloimonos, J. VL - 65 CP - 3 ER - TY - CONF T1 - Space-time tradeoffs for approximate spherical range counting T2 - Proceedings of the sixteenth annual ACM-SIAM symposium on Discrete algorithms Y1 - 2005 A1 - Arya,Sunil A1 - Malamatos,Theocharis A1 - Mount, Dave AB - We present space-time tradeoffs for approximate spherical range counting queries. Given a set S of n data points in Rd along with a positive approximation factor ε, the goal is to preprocess the points so that, given any Euclidean ball B, we can return the number of points of any subset of S that contains all the points within a (1 - ε)-factor contraction of B, but contains no points that lie outside a (1 + ε)-factor expansion of B.In many applications of range searching it is desirable to offer a tradeoff between space and query time. We present here the first such tradeoffs for approximate range counting queries. Given 0 < ε ≤ 1/2 and a parameter γ, where 2 ≤ γ ≤ 1/ε, we show how to construct a data structure of space O(nγd log (1/ε)) that allows us to answer ε-approximate spherical range counting queries in time O(log(nγ) + 1/(εγd-1). The data structure can be built in time O(nγd log (n/ε)) log (1/ε)). Here n, ε, and γ are asymptotic quantities, and the dimension d is assumed to be a fixed constant.At one extreme (low space), this yields a data structure of space O(n log (1/e)) that can answer approximate range queries in time O(logn + 1/(ed-1) which, up to a factor of O(n log (1/e) in space, matches the best known result for approximate spherical range counting queries. At the other extreme (high space), it yields a data structure of space O((n/ed) log(1/ε)) that can answer queries in time O(logn + 1/ε). This is the fastest known query time for this problem.We also show how to adapt these data structures to the problem of computing an ε-approximation to the kth nearest neighbor, where k is any integer from 1 to n given at query time. The space bounds are identical to the range searching results, and the query time is larger only by a factor of O(1/(εγ)).Our approach is broadly based on methods developed for approximate Voronoi diagrams (AVDs), but it involves a number of significant extensions from the context of nearest neighbor searching to range searching. These include generalizing AVD node-separation properties from leaves to internal nodes of the tree and constructing efficient generator sets through a radial decomposition of space. We have also developed new arguments to analyze the time and space requirements in this more general setting. JA - Proceedings of the sixteenth annual ACM-SIAM symposium on Discrete algorithms T3 - SODA '05 PB - Society for Industrial and Applied Mathematics CY - Philadelphia, PA, USA SN - 0-89871-585-7 UR - http://dl.acm.org/citation.cfm?id=1070432.1070505 ER - TY - JOUR T1 - Structural Determinants for Selective Recognition of a Lys48-Linked Polyubiquitin Chain by a UBA Domain JF - Molecular Cell Y1 - 2005 A1 - Varadan,Ranjani A1 - Assfalg,Michael A1 - Raasi,Shahri A1 - Pickart,Cecile A1 - Fushman, David AB - SummaryAlthough functional diversity in polyubiquitin chain signaling has been ascribed to the ability of differently linked chains to bind in a distinctive manner to effector proteins, structural models of such interactions have been lacking. Here, we use NMR to unveil the structural basis of selective recognition of Lys48-linked di- and tetraubiquitin chains by the UBA2 domain of hHR23A. Although the interaction of UBA2 with Lys48-linked diubiquitin involves the same hydrophobic surface on each ubiquitin unit as that utilized in monoubiquitin:UBA complexes, our results show how the “closed” conformation of Lys48-linked diubiquitin is crucial for high-affinity binding. Moreover, recognition of Lys48-linked diubiquitin involves a unique epitope on UBA, which allows the formation of a sandwich-like diubiqutin:UBA complex. Studies of the UBA-tetraubiquitin interaction suggest that this mode of UBA binding to diubiquitin is relevant for longer chains. VL - 18 SN - 1097-2765 UR - http://www.sciencedirect.com/science/article/pii/S1097276505013195 CP - 6 M3 - 10.1016/j.molcel.2005.05.013 ER - TY - CONF T1 - Toward resilient security in wireless sensor networks T2 - Proceedings of the 6th ACM international symposium on Mobile ad hoc networking and computing Y1 - 2005 A1 - Yang,H. A1 - Ye,F. A1 - Yuan,Y. A1 - Lu,S. A1 - Arbaugh, William A. JA - Proceedings of the 6th ACM international symposium on Mobile ad hoc networking and computing ER - TY - CONF T1 - Turning information visualization innovations into commercial products: lessons to guide the next success T2 - IEEE Symposium on Information Visualization, 2005. INFOVIS 2005 Y1 - 2005 A1 - Shneiderman, Ben A1 - Rao,R. A1 - Andrews,K. A1 - Ahlberg,C. A1 - Brodbeck,D. A1 - Jewitt,T. A1 - Mackinlay,J. KW - Books KW - commercial development KW - commercial product KW - Computer interfaces KW - Computer science KW - data visualisation KW - Data visualization KW - Educational institutions KW - exploratory data analysis KW - information visualization innovation KW - information visualization tool KW - innovation management KW - Laboratories KW - Management training KW - new technology emergence KW - Technological innovation KW - technology transfer KW - Turning KW - User interfaces AB - As information visualization matures as an academic research field, commercial spinoffs are proliferating, but success stories are harder to find. This is the normal process of emergence for new technologies, but the panel organizers believe that there are certain strategies that facilitate success. To teach these lessons, we have invited several key figures who are seeking to commercialize information visualization tools. The panelists make short presentations, engage in a moderated discussion, and respond to audience questions. JA - IEEE Symposium on Information Visualization, 2005. INFOVIS 2005 PB - IEEE SN - 0-7803-9464-X M3 - 10.1109/INFVIS.2005.1532153 ER - TY - CONF T1 - UMD Experiments with FRGC Data T2 - Computer Vision and Pattern Recognition - Workshops, 2005. CVPR Workshops. IEEE Computer Society Conference on Y1 - 2005 A1 - Aggarwal,G. A1 - Biswas,S. A1 - Chellapa, Rama AB - Although significant work has been done in the field of face recognition, the performance of state-of-the art face recognition algorithms is not good enough to be effective in operational systems. Though most algorithms work well for controlled images, they are quite susceptible to changes in illumination and pose. Face Recognition Grand Challenge (FRGC) is an effort to examine such issues to suitably guide future research in the area. This paper describes the efforts made at UMD in this direction. We present our results on several experiments suggested in FRGC. We believe that though pattern classification techniques play an extremely significant role in automatic face recognition under controlled conditions, physical modeling is required to generalize across varying situations. Accordingly, we describe a generative approach to recognize faces across varying illumination. Unlike most current methods, our method does not ignore shadows. Instead we use them to our benefit by modeling attached shadows in our formulation. JA - Computer Vision and Pattern Recognition - Workshops, 2005. CVPR Workshops. IEEE Computer Society Conference on M3 - 10.1109/CVPR.2005.586 ER - TY - CHAP T1 - Using NMR Spectroscopy to Monitor Ubiquitin Chain Conformation and Interactions with Ubiquitin‐Binding Domains T2 - Ubiquitin and Protein Degradation, Part B Y1 - 2005 A1 - Varadan,Ranjani A1 - Assfalg,Michael A1 - Fushman, David ED - Deshaies,Raymond J. AB - Polyubiquitin (polyUb) chains function as signaling molecules that mediate a diverse set of cellular events. The outcome of polyubiquitination depends on the specific linkage between Ub moieties in the chain, and differently linked chains function as distinct intracellular signals. Although an increasing number of Ub‐binding proteins that transmit the regulatory information conferred by (poly)ubiquitination have been identified, the molecular mechanisms of linkage‐specific signaling and recognition still remain to be understood. Knowledge of the chain structure is expected to provide insights into the basis of diversity in polyUb signaling. Here we describe several NMR approaches aimed at determining the physiological conformation of polyUb and characterization of the chains' interactions with ubiquitin‐binding proteins. JA - Ubiquitin and Protein Degradation, Part B PB - Academic Press VL - Volume 399 SN - 0076-6879 UR - http://www.sciencedirect.com/science/article/pii/S0076687905990125 ER - TY - CHAP T1 - Web Service Composition with Volatile Information T2 - The Semantic Web – ISWC 2005 Y1 - 2005 A1 - Au,Tsz-Chiu A1 - Kuter,Ugur A1 - Nau, Dana S. ED - Gil,Yolanda ED - Motta,Enrico ED - Benjamins,V. ED - Musen,Mark KW - Computer science AB - In many Web service composition problems, information may be needed from Web services during the composition process. Existing research on Web service composition (WSC) procedures has generally assumed that this information will not change. We describe two ways to take such WSC procedures and systematically modify them to deal with volatile information. The black-box approach requires no knowledge of the WSC procedure’s internals: it places a wrapper around the WSC procedure to deal with volatile information. The gray-box approach requires partial information of those internals, in order to insert coding to perform certain bookkeeping operations. We show theoretically that both approaches work correctly. We present experimental results showing that the WSC procedures produced by the gray-box approach can run much faster than the ones produced by the black-box approach. JA - The Semantic Web – ISWC 2005 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3729 SN - 978-3-540-29754-3 UR - http://www.springerlink.com/content/y105x8464k54l760/abstract/ ER - TY - JOUR T1 - Weighted coloring based channel assignment for WLANs JF - ACM SIGMOBILE Mobile Computing and Communications Review Y1 - 2005 A1 - Mishra,A. A1 - Banerjee,S. A1 - Arbaugh, William A. VL - 9 CP - 3 ER - TY - CONF T1 - 3D model refinement using surface-parallax T2 - Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04). IEEE International Conference on Y1 - 2004 A1 - Agrawala, Ashok K. A1 - Chellapa, Rama KW - 3D KW - adaptive KW - arbitrary KW - camera KW - coarse KW - compensation; KW - Computer KW - DEM; KW - depth KW - digital KW - ELEVATION KW - environments; KW - epipolar KW - estimation; KW - field; KW - image KW - incomplete KW - INTENSITY KW - map; KW - model KW - MOTION KW - parallax; KW - plane-parallax KW - reconstruction; KW - recovery; KW - refinement; KW - sequence; KW - sequences; KW - surface KW - surfaces; KW - urban KW - vision; KW - windowing; AB - We present an approach to update and refine coarse 3D models of urban environments from a sequence of intensity images using surface parallax. This generalizes the plane-parallax recovery methods to surface-parallax using arbitrary surfaces. A coarse and potentially incomplete depth map of the scene obtained from a digital elevation map (DEM) is used as a reference surface which is refined and updated using this approach. The reference depth map is used to estimate the camera motion and the motion of the 3D points on the reference surface is compensated. The resulting parallax, which is an epipolar field, is estimated using an adaptive windowing technique and used to obtain the refined depth map. JA - Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04). IEEE International Conference on VL - 3 M3 - 10.1109/ICASSP.2004.1326537 ER - TY - CONF T1 - Achieving packet-level quality of service through scheduling in multirate WLANs T2 - Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th Y1 - 2004 A1 - Yuan Yuan A1 - Daqing Gu A1 - Arbaugh, William A. A1 - Jinyun Zhang KW - Analytical models KW - channel conditions KW - channel errors KW - channel temporal fair share KW - compensation KW - Computer science KW - Delay KW - error-prone flow compensation KW - IEEE 802.11a/b/g physical layer KW - multirate wireless fair scheduling KW - multirate WLAN KW - packet radio networks KW - packet-level quality of service KW - Physical layer KW - Processor scheduling KW - QoS KW - quality of service KW - radio access networks KW - Scheduling algorithm KW - Throughput KW - throughput fairness KW - USA Councils KW - Wireless LAN KW - wireless packet scheduling KW - WMFS AB - Wireless packet scheduling has been a popular paradigm to achieve packet-level QoS in terms of fairness and throughput in the presence of channel errors. However, the current design does not anticipate the multi-rate capability offered by the IEEE 802.11a/b/g physical layer, thus suffering significant performance degradation in 802.11 WLANs. In this paper, we propose multirate wireless fair scheduling (WMFS). In MWFS, each flow is granted a temporal fair share of the channel, in contrast to the throughput fair share adopted by existing algorithms. Therefore, each flow receives services in proportion to its perceived transmission rate, and high-rate flows are able to opportunistically exploit their good channel conditions and receive more services. MWFS also renovates the compensation model in order to allow for error-prone flows to catch up, thus ensuring fairness for all flows over error-prone channels. We demonstrate the effectiveness of MWFS through both simulations and analysis. Especially, WMFS achieves system throughput 159% of state-of-the-art scheduling algorithms in simulated scenarios. JA - Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th PB - IEEE VL - 4 SN - 0-7803-8521-7 M3 - 10.1109/VETECF.2004.1400554 ER - TY - JOUR T1 - Active deformable models using density estimation JF - International Journal of Image and Graphics Y1 - 2004 A1 - Abd-Almageed, Wael A1 - Smith,C.E. VL - 4 CP - 3 ER - TY - CONF T1 - Active logic for more effective human-computer interaction and other commonsense applications T2 - Proceedings of the Workshop Empirically Successful First-Order Reasoning, International Joint Conference on Automated Reasoning Y1 - 2004 A1 - Anderson,M. L A1 - Josyula,D. A1 - Perlis, Don A1 - Purang,K. JA - Proceedings of the Workshop Empirically Successful First-Order Reasoning, International Joint Conference on Automated Reasoning ER - TY - JOUR T1 - The Argus eye, a new tool for robotics JF - IEEE Robotics and Automation Magazine Y1 - 2004 A1 - Baker, P. A1 - Ogale, A. S A1 - Fermüller, Cornelia A1 - Aloimonos, J. VL - 11 CP - 4 ER - TY - CONF T1 - Challenges in Measuring HPCS Learner Productivity in an Age of Ubiquitous Computing: The HPCS Program T2 - In Proceedings of ICSE Workshop on High Productivity Computing. May 2004 Y1 - 2004 A1 - Asgari, S. A1 - Basili, Victor R. A1 - Carver, J. A1 - Hochstein, L. A1 - Hollingsworth, Jeffrey K A1 - Zelkowitz, Marvin V JA - In Proceedings of ICSE Workshop on High Productivity Computing. May 2004 ER - TY - CONF T1 - A comparison of bug finding tools for Java T2 - Software Reliability Engineering, 2004. ISSRE 2004. 15th International Symposium on Y1 - 2004 A1 - Rutar,N. A1 - Almazan,C.B. A1 - Foster, Jeffrey S. JA - Software Reliability Engineering, 2004. ISSRE 2004. 15th International Symposium on ER - TY - CONF T1 - Compound eye sensor for 3D ego motion estimation T2 - 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2004. (IROS 2004). Proceedings Y1 - 2004 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Brajovic,V. KW - 3D camera motion estimation KW - CAMERAS KW - compound eye vision sensor KW - Computer vision KW - Equations KW - Eyes KW - Geometry KW - Image sensors KW - Insects KW - linear equations KW - Motion estimation KW - robot vision KW - Robustness KW - sampling geometry KW - Sampling methods KW - Sensor phenomena and characterization AB - We describe a compound eye vision sensor for 3D ego motion computation. Inspired by eyes of insects, we show that the compound eye sampling geometry is optimal for 3D camera motion estimation. This optimality allows us to estimate the 3D camera motion in a scene-independent and robust manner by utilizing linear equations. The mathematical model of the new sensor can be implemented in analog networks resulting in a compact computational sensor for instantaneous 3D ego motion measurements in full six degrees of freedom. JA - 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2004. (IROS 2004). Proceedings PB - IEEE VL - 4 SN - 0-7803-8463-6 M3 - 10.1109/IROS.2004.1389992 ER - TY - CONF T1 - Copilot - a coprocessor-based kernel runtime integrity monitor T2 - Proceedings of the 13th conference on USENIX Security Symposium - Volume 13 Y1 - 2004 A1 - Petroni,Jr. A1 - Fraser,Timothy A1 - Molina,Jesus A1 - Arbaugh, William A. KW - design KW - management KW - MONITORS KW - Security KW - security and protection AB - Copilot is a coprocessor-based kernel integrity monitor for commodity systems. Copilot is designed to detect malicious modifications to a host's kernel and has correctly detected the presence of 12 real-world rootkits, each within 30 seconds of their installation with less than a 1% penalty to the host's performance. Copilot requires no modifications to the protected host's software and can be expected to operate correctly even when the host kernel is thoroughly compromised - an advantage over traditional monitors designed to run on the host itself. JA - Proceedings of the 13th conference on USENIX Security Symposium - Volume 13 T3 - SSYM'04 PB - USENIX Association CY - San Diego, CA UR - http://portal.acm.org/citation.cfm?id=1251375.1251388 ER - TY - CONF T1 - Divergence Unraveling for Word Alignment... T2 - Natural Language Engineering Y1 - 2004 A1 - Dorr, Bonnie J A1 - Ayan,N.F. A1 - Habash,N. AB - We describe the use of parallel text for divergence unraveling in word-level alignment. DUSTer (Divergence Unraveling for Statistical Translation) is a system that combines linguistic and statistical knowledge to resolve structural di#erences between languages, i.e., translation divergences, during the process of alignment. Our immediate goal is to induce word-level alignments that are more accurate than those produced by an existing state-ofthe -art statistical system. The long-term goal is to improve the output quality of statistical machine translation and lexical acquisition systems by using DUSTer as one possible input to a framework that accommodates multiple alignments. We show that a systematic characterization of alignment errors made by a statistical system validates the use of linguistically-motivated universal rules for identifying and handling divergences. These rules relate one or more linguistically-motivated categories associated with the (English) input words to those of another language (foreign language); the resulting match sets are used to infer corrected alignments. Using a human-aligned corpus as our gold standard, we demonstrate an improvement in alignments over an existing state-of-the-art alignment algorithm. JA - Natural Language Engineering ER - TY - CONF T1 - Domain-independent reason-enhanced controller for task-oriented systems-DIRECTOR T2 - PROCEEDINGS OF THE NATIONAL CONFERENCE ON ARTIFICIAL IN℡LIGENCE Y1 - 2004 A1 - Josyula,D. P A1 - Anderson,M. L A1 - Perlis, Don JA - PROCEEDINGS OF THE NATIONAL CONFERENCE ON ARTIFICIAL IN℡LIGENCE ER - TY - JOUR T1 - Efficient Execution of Multi-Query Data Analysis Batches Using Compiler Optimization Strategies JF - Languages and Compilers for Parallel Computing Y1 - 2004 A1 - Andrade,H. A1 - Aryangat,S. A1 - Kurc, T. A1 - Saltz, J. A1 - Sussman, Alan AB - This work investigates the leverage that can be obtained from compiler optimization techniques for efficient execution of multi-query workloads in data analysis applications. Our approach is to address multi-query optimization at the algorithmic level, by transforming a declarative specification of scientific data analysis queries into a high-level imperative program that can be made more efficient by applying compiler optimization techniques. These techniques – including loop fusion, common subexpression elimination and dead code elimination – are employed to allow data and computation reuse across queries. We describe a preliminary experimental analysis on a real remote sensing application that analyzes very large quantities of satellite data. The results show our techniques achieve sizable reductions in the amount of computation and I/O necessary for executing query batches and in average execution times for the individual queries in a given batch. M3 - 10.1007/978-3-540-24644-2_33 ER - TY - CONF T1 - Empirical-based estimation of the effect on software dependability of a technique for architecture conformance verification T2 - Proceedings of the ICSE 2004 Workshop on Architecting Dependable Systems, Edinburgh, UK Y1 - 2004 A1 - Asgari, S. A1 - Basili, Victor R. A1 - Costa,P. A1 - Donzelli,P. A1 - Hochstein, L. A1 - Lindvall,M. A1 - Rus,I. A1 - Shull, F. A1 - Tvedt,R. A1 - Zelkowitz, Marvin V AB - The High Dependability Computing Program (HDCP)project is a NASA initiative for increasing dependability of software-based systems. It researches achieving high dependability by introducing new technologies. We focus on the evaluation of the effectiveness of technologies with respect to dependability. We employ empirical evaluation methods along with evaluation testbeds. In this paper, our technology evaluation approach is described. A testbed representative of air traffic control applications is used. An experiment to evaluate a technology to for identification of architectural violations is presented. JA - Proceedings of the ICSE 2004 Workshop on Architecting Dependable Systems, Edinburgh, UK ER - TY - CONF T1 - Ferret: a host vulnerability checking tool Y1 - 2004 A1 - Sharma,Anil A1 - Martin,J.R. A1 - Anand,N. A1 - Cukier, Michel A1 - Sanders,W. H. KW - Ferret software tool KW - host vulnerability checking tool KW - open-source software KW - Perl KW - plug-in module KW - program verification KW - security auditing tool KW - security evaluation KW - security of data KW - software tools AB - Evaluation of computing system security requires knowledge of the vulnerabilities present in the system and of potential attacks against the system. Vulnerabilities can be classified based on their location as application vulnerabilities, network vulnerabilities, or host vulnerabilities. We describe Ferret, a new software tool for checking host vulnerabilities. Ferret helps system administrators by quickly finding vulnerabilities that are present on a host. It is designed and implemented in a modular way: a different plug-in module is used for each vulnerability checked, and each possible output format is specified by a plug-in module. As a result, Ferret is extensible, and can easily be kept up-to-date through addition of checks for new vulnerabilities as they are discovered; the modular approach also makes it easy to provide specific configurations of Ferret tailored to specific operating systems or use environments. Ferret is a freely available open-source software implemented in Perl. M3 - 10.1109/PRDC.2004.1276595 ER - TY - JOUR T1 - A hierarchy of cameras for 3D photography JF - Computer Vision and Image Understanding Y1 - 2004 A1 - Neumann, Jan A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - Camera design KW - Multi-view geometry KW - Polydioptric cameras KW - Spatio-temporal image analysis KW - structure from motion AB - The view-independent visualization of 3D scenes is most often based on rendering accurate 3D models or utilizes image-based rendering techniques. To compute the 3D structure of a scene from a moving vision sensor or to use image-based rendering approaches, we need to be able to estimate the motion of the sensor from the recorded image information with high accuracy, a problem that has been well-studied. In this work, we investigate the relationship between camera design and our ability to perform accurate 3D photography, by examining the influence of camera design on the estimation of the motion and structure of a scene from video data. By relating the differential structure of the time varying plenoptic function to different known and new camera designs, we can establish a hierarchy of cameras based upon the stability and complexity of the computations necessary to estimate structure and motion. At the low end of this hierarchy is the standard planar pinhole camera for which the structure from motion problem is non-linear and ill-posed. At the high end is a camera, which we call the full field of view polydioptric camera, for which the motion estimation problem can be solved independently of the depth of the scene which leads to fast and robust algorithms for 3D Photography. In between are multiple view cameras with a large field of view which we have built, as well as omni-directional sensors. VL - 96 SN - 1077-3142 UR - http://www.sciencedirect.com/science/article/pii/S1077314204000505 CP - 3 M3 - 10.1016/j.cviu.2004.03.013 ER - TY - CONF T1 - High-performance MAC for high-capacity wireless LANs T2 - 13th International Conference on Computer Communications and Networks, 2004. ICCCN 2004. Proceedings Y1 - 2004 A1 - Yuan Yuan A1 - Daqing Gu A1 - Arbaugh, William A. A1 - Jinyun Zhang KW - 35 Mbit/s KW - access protocols KW - Aggregates KW - Bandwidth KW - batch transmission KW - Computer science KW - Educational institutions KW - high-capacity wireless LAN KW - high-performance MAC KW - Laboratories KW - Local area networks KW - Media Access Protocol KW - opportunistic selection KW - Physical layer KW - probability KW - Throughput KW - Wireless LAN AB - The next-generation wireless technologies, e.g., 802.11n and 802.15.3a, offer a physical-layer speed at least an-order-of-magnitude higher than the current standards. However, direct application of current MACs leads to high protocol overhead and significant throughput degradation. In this paper, we propose ADCA, a high-performance MAC that works with high-capacity physical layer. ADCA exploits two ideas of adaptive batch transmission and opportunistic selection of high-rate hosts to simultaneously reduce the overhead and improve the aggregate throughput. It opportunistically favors high-rate hosts by providing higher access probability and more access time, while ensuring each low-rate host certain minimum amount of channel access time. Simulations show that the ADCA design increases the throughput by 112% and reduces the average delay by 55% compared with the legacy DCF. It delivers more than 100 Mbps MAC-layer throughput as compared with 35 Mbps offered by the legacy MAC JA - 13th International Conference on Computer Communications and Networks, 2004. ICCCN 2004. Proceedings PB - IEEE SN - 0-7803-8814-3 M3 - 10.1109/ICCCN.2004.1401615 ER - TY - CONF T1 - The influence of shape on image correspondence T2 - 2nd International Symposium on 3D Data Processing, Visualization and Transmission, 2004. 3DPVT 2004. Proceedings Y1 - 2004 A1 - Ogale, A. S A1 - Aloimonos, J. KW - Automation KW - CAMERAS KW - Computational modeling KW - first order approximation KW - Geometrical optics KW - hidden feature removal KW - image sampling KW - Image segmentation KW - Layout KW - occlusion detection KW - piecewise continuous function KW - Pixel KW - SHAPE KW - Simulated annealing KW - stereo image processing KW - surface fitting AB - We examine the implications of shape on the process of finding dense correspondence and half-occlusions for a stereo pair of images. The desired property of the depth map is that it should be a piecewise continuous function which is consistent with the images and which has the minimum number of discontinuities. To zeroeth order, piecewise continuity becomes piecewise constancy. Using this approximation, we first discuss an approach for dealing with such a fronto-parallel shapeless world, and the problems involved therein. We then introduce horizontal and vertical slant to create a first order approximation to piecewise continuity. We highlight the fact that a horizontally slanted surface (ie. having depth variation in the direction of the separation of the two cameras) appears horizontally stretched in one image as compared to the other image. Thus, while corresponding two images, N pixels on a scanline in one image may correspond to a different number of pixels M in the other image, which has consequences with regard to sampling and occlusion detection. We also discuss the asymmetry between vertical and horizontal slant, and the central role of nonhorizontal edges in the context of vertical slant. Using experiments, we discuss cases where existing algorithms fail, and how the incorporation of new constraints provides correct results. JA - 2nd International Symposium on 3D Data Processing, Visualization and Transmission, 2004. 3DPVT 2004. Proceedings PB - IEEE SN - 0-7695-2223-8 M3 - 10.1109/TDPVT.2004.1335418 ER - TY - PAT T1 - Method of designing signaling networks for internet telephony Y1 - 2004 A1 - Aravamudan,Murali A1 - Kumaran,Krishnan A1 - Ramakrishnan,Kajamalai Gopalaswamy A1 - Srinivasan, Aravind ED - Lucent Technologies Inc. AB - A method is disclosed for designing a signaling network of call coordinators (CCs) for internet telephony. The new method can be used to design a CC network of arbitrary size that satisfies, with high probability, limitations on the maximum number of sockets per CC and on the maximum number of hops between an arbitrary pair of switches in the network. According to the disclosed method, the network of CCs is treated initially as a collection of isolated points, one point for each CC. Then, links are added between pairs of CCs, excluding pairs lying within the same switch. The links are added randomly, but with a particular probability p, which may be different for different pairs. Thus, whether a given link is added depends, in effect, upon the outcome of a loaded coin toss in which the probability of a positive outcome is p. VL - : 09/517,658 UR - http://www.google.com/patents?id=VTsSAAAAEBAJ CP - 6687363 ER - TY - CHAP T1 - Multi-align: Combining Linguistic and Statistical Techniques to Improve Alignments for Adaptable MT T2 - Machine Translation: From Real Users to ResearchMachine Translation: From Real Users to Research Y1 - 2004 A1 - Ayan,Necip A1 - Dorr, Bonnie J A1 - Habash,Nizar ED - Frederking,Robert ED - Taylor,Kathryn AB - An adaptable statistical or hybrid MT system relies heavily on the quality of word-level alignments of real-world data. Statistical alignment approaches provide a reasonable initial estimate for word alignment. However, they cannot handle certain types of linguistic phenomena such as long-distance dependencies and structural differences between languages. We address this issue in Multi-Align, a new framework for incremental testing of different alignment algorithms and their combinations. Our design allows users to tune their systems to the properties of a particular genre/domain while still benefiting from general linguistic knowledge associated with a language pair. We demonstrate that a combination of statistical and linguistically-informed alignments can resolve translation divergences during the alignment process. JA - Machine Translation: From Real Users to ResearchMachine Translation: From Real Users to Research T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 3265 SN - 978-3-540-23300-8 UR - http://dx.doi.org/10.1007/978-3-540-30194-3_3 ER - TY - CHAP T1 - Plan Databases: Model and Algebra T2 - Foundations of Information and Knowledge Systems Y1 - 2004 A1 - Yaman,Fusun A1 - Adali,Sibel A1 - Nau, Dana S. A1 - Sapino,Maria A1 - Subrahmanian,V. ED - Seipel,Dietmar ED - Turull-Torres,José KW - Computer science AB - Despite the fact that thousands of applications manipulate plans, there has been no work to date on managing large databases of plans. In this paper, we first propose a formal model of plan databases. We describe important notions of consistency and coherence for such databases. We then propose a set of operators similar to the relational algebra to query such databases of plans. JA - Foundations of Information and Knowledge Systems T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2942 SN - 978-3-540-20965-2 UR - http://www.springerlink.com/content/yqhlqtu4te18q2e1/abstract/ ER - TY - CONF T1 - The priority curve algorithm for video summarization T2 - Proceedings of the 2nd ACM international workshop on Multimedia databases Y1 - 2004 A1 - Fayzullin,M. A1 - V.S. Subrahmanian A1 - Albanese, M. A1 - Picariello, A. KW - probabilistic KW - Summarization KW - system KW - video AB - In this paper, we introduce the concept of a priority curve associated with a video. We then provide an algorithm that can use the priority curve to create a summary (of a desired length) of any video. The summary thus created exhibits nice continuity properties and also avoids repetition. We have implemented the priority curve algorithm (PCA) and compared it with other summarization algorithms in the literature. We show that PCA is faster than existing algorithms and also produces better quality summaries. The quality of summaries was evaluated by a group of 200 students in Naples, Italy, who watched soccer videos. We also briefly describe a soccer video summarization system we have built on using the PCA architecture and various (classical) image processing algorithms. JA - Proceedings of the 2nd ACM international workshop on Multimedia databases T3 - MMDB '04 PB - ACM CY - New York, NY, USA SN - 1-58113-975-6 UR - http://doi.acm.org/10.1145/1032604.1032611 M3 - 10.1145/1032604.1032611 ER - TY - JOUR T1 - Proactive key distribution using neighbor graphs JF - IEEE Wireless Communications Y1 - 2004 A1 - Mishra,A. A1 - Min Ho Shin A1 - Petroni,N. L. A1 - Clancy,T. C A1 - Arbaugh, William A. KW - access points KW - Authentication KW - authentication time KW - Base stations KW - Communication system security KW - Delay KW - graph theory KW - GSM KW - IEEE 802.11 handoff KW - Land mobile radio cellular systems KW - Message authentication KW - mobile radio KW - Multiaccess communication KW - neighbor graph KW - Network topology KW - Roaming KW - telecommunication security KW - Telephone sets KW - user mobility KW - Wi-Fi networks KW - wireless data networks KW - Wireless LAN KW - Wireless networks AB - User mobility in wireless data networks is increasing because of technological advances, and the desire for voice and multimedia applications. These applications, however, require that handoffs between base stations (or access points) be fast to maintain the quality of the connections. In this article we introduce a novel data structure, the neighbor graph, that dynamically captures the mobility topology of a wireless network. We show how neighbor graphs can be utilized to obtain a 99 percent reduction in the authentication time of an IEEE 802.11 handoff (full EAP-TLS) by proactively distributing necessary key material one hop ahead of the mobile user. We also present a reactive method for fast authentication that requires only firmware changes to access points and hence can easily be deployed on existing wireless networks. VL - 11 SN - 1536-1284 CP - 1 M3 - 10.1109/MWC.2004.1269714 ER - TY - JOUR T1 - Robotics & Automation Magazine Vol. 11 JF - IEEE Robotics & Automation Magazine Y1 - 2004 A1 - Aliaga, D.G. A1 - Allen,PK A1 - Archibald,JK A1 - Argyros,AA A1 - Arkin,RC A1 - Baker,C. A1 - Baker, P. A1 - Beard,RW A1 - Bicchi,A. A1 - Birgmajer,B. A1 - others ER - TY - CONF T1 - Robust ego-motion estimation and 3D model refinement using depth based parallax model T2 - Image Processing, 2004. ICIP '04. 2004 International Conference on Y1 - 2004 A1 - Agrawala, Ashok K. A1 - Chellapa, Rama KW - 3D KW - algorithm; KW - analysis; KW - and KW - based KW - camera; KW - coarse KW - compensation; KW - DEM; KW - depth KW - digital KW - ego-motion KW - eigen-value KW - eigenfunctions; KW - eigenvalues KW - ELEVATION KW - epipolar KW - estimation; KW - extraction; KW - feature KW - field; KW - iteration KW - iterative KW - map; KW - method; KW - methods; KW - model KW - model; KW - MOTION KW - parallax KW - partial KW - range-finding; KW - refinement; KW - refining; KW - surface AB - We present an iterative algorithm for robustly estimating the ego-motion and refining and updating a coarse, noisy and partial depth map using a depth based parallax model and brightness derivatives extracted from an image pair. Given a coarse, noisy and partial depth map acquired by a range-finder or obtained from a Digital Elevation Map (DFM), we first estimate the ego-motion by combining a global ego-motion constraint and a local brightness constancy constraint. Using the estimated camera motion and the available depth map estimate, motion of the 3D points is compensated. We utilize the fact that the resulting surface parallax field is an epipolar field and knowing its direction from the previous motion estimates, estimate its magnitude and use it to refine the depth map estimate. Instead of assuming a smooth parallax field or locally smooth depth models, we locally model the parallax magnitude using the depth map, formulate the problem as a generalized eigen-value analysis and obtain better results. In addition, confidence measures for depth estimates are provided which can be used to remove regions with potentially incorrect (and outliers in) depth estimates for robustly estimating ego-motion in the next iteration. Results on both synthetic and real examples are presented. JA - Image Processing, 2004. ICIP '04. 2004 International Conference on VL - 4 M3 - 10.1109/ICIP.2004.1421606 ER - TY - JOUR T1 - Security issues in IEEE 802.11 wireless local area networks: a survey JF - Wireless Communications and Mobile Computing Y1 - 2004 A1 - Mishra,A. A1 - Petroni Jr,N. L A1 - Arbaugh, William A. A1 - Fraser,T. VL - 4 CP - 8 ER - TY - JOUR T1 - Solution Conformation of Lys63-linked Di-ubiquitin Chain Provides Clues to Functional Diversity of Polyubiquitin Signaling JF - Journal of Biological ChemistryJ. Biol. Chem. Y1 - 2004 A1 - Varadan,Ranjani A1 - Assfalg,Michael A1 - Haririnia,Aydin A1 - Raasi,Shahri A1 - Pickart,Cecile A1 - Fushman, David AB - Diverse cellular events are regulated by post-translational modification of substrate proteins via covalent attachment of one or a chain of ubiquitin molecules. The outcome of (poly)ubiquitination depends upon the specific lysine residues involved in the formation of polyubiquitin chains. Lys48-linked chains act as a universal signal for proteasomal degradation, whereas Lys63-linked chains act as a specific signal in several non-degradative processes. Although it has been anticipated that functional diversity between alternatively linked polyubiquitin chains relies on linkage-dependent differences in chain conformation/topology, direct structural evidence in support of this model has been lacking. Here we use NMR methods to determine the structure of a Lys63-linked di-ubiquitin chain. The structure is characterized by an extended conformation, with no direct contact between the hydrophobic residues Leu8, Ile44, and Val70 on the ubiquitin units. This structure contrasts with the closed conformation observed for Lys48-linked di-ubiquitin wherein these residues form the interdomain interface (Cook, W. J., Jeffrey, L. C., Carson, M., Zhijian, C., and Pickart, C. M. (1992) J. Biol. Chem. 267, 16467-16471; Varadan, R., Walker, O., Pickart, C., and Fushman, D. (2002) J. Mol. Biol. 324, 637-647). Consistent with the open conformation of the Lys63-linked di-ubiquitin, our binding studies show that both ubiquitin domains in this chain can bind a ubiquitin-associated domain from HHR23A independently and in a mode similar to that for mono-ubiquitin. In contrast, Lys48-linked di-ubiquitin binds in a different, higher affinity mode that has yet to be determined. This is the first experimental evidence that alternatively linked polyubiquitin chains adopt distinct conformations. VL - 279 SN - 0021-9258, 1083-351X UR - http://www.jbc.org/content/279/8/7055 CP - 8 M3 - 10.1074/jbc.M309184200 ER - TY - CONF T1 - Stereo Correspondence with Slanted Surfaces: Critical Implications of Horizontal Slant T2 - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on Y1 - 2004 A1 - Ogale, Abhijit S. A1 - Aloimonos, J. AB - We examine the stereo correspondence problem in the presence of slanted scene surfaces. In particular, we highlight a previously overlooked geometric fact: a horizontally slanted surface (i.e. having depth variation in the direction of the separation of the two cameras) will appear horizontally stretched in one image as compared to the other image. Thus, while corresponding two images, N pixels on a scanline in one image may correspond to a different number of pixels M in the other image. This leads to three important modifications to existing stereo algorithms: (a) due to unequal sampling, intensity matching metrics such as the popular Birchfield-Tomasi procedure must be modified, (b) unequal numbers of pixels in the two images must be allowed to correspond to each other, and (c) the uniqueness constraint, which is often used for detecting occlusions, must be changed to a 3D uniqueness constraint. This paper discusses these new constraints and provides a simple scanline based matching algorithm for illustration. We experimentally demonstrate test cases where existing algorithms fail, and how the incorporation of these new constraints provides correct results. Experimental comparisons of the scanline based algorithm with standard data sets are also provided. JA - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on PB - IEEE Computer Society CY - Los Alamitos, CA, USA VL - 1 M3 - http://doi.ieeecomputersociety.org/10.1109/CVPR.2004.241 ER - TY - JOUR T1 - Structure from motion of parallel lines JF - Computer Vision-ECCV 2004 Y1 - 2004 A1 - Baker, P. A1 - Aloimonos, J. ER - TY - CONF T1 - Studying code development for high performance computing: the HPCS program T2 - First International Workshop On Software Engineering for High Performance Computing System Applications Y1 - 2004 A1 - Carver, J. A1 - Asgari, S. A1 - Basili, Victor R. A1 - Hochstein, L. A1 - Hollingsworth, Jeffrey K A1 - Shull, F. A1 - Zelkowitz, Marvin V JA - First International Workshop On Software Engineering for High Performance Computing System Applications ER - TY - CONF T1 - A system identification approach for video-based face recognition T2 - Pattern Recognition, 2004. ICPR 2004. Proceedings of the 17th International Conference on Y1 - 2004 A1 - Aggarwal,G. A1 - Chowdhury, A.K.R. A1 - Chellapa, Rama KW - and KW - autoregressive KW - average KW - dynamical KW - Face KW - gallery KW - identification; KW - image KW - linear KW - model; KW - moving KW - processes; KW - processing; KW - recognition; KW - sequences; KW - signal KW - system KW - system; KW - video KW - video-based AB - The paper poses video-to-video face recognition as a dynamical system identification and classification problem. We model a moving face as a linear dynamical system whose appearance changes with pose. An autoregressive and moving average (ARMA) model is used to represent such a system. The choice of ARMA model is based on its ability to take care of the change in appearance while modeling the dynamics of pose, expression etc. Recognition is performed using the concept of sub space angles to compute distances between probe and gallery video sequences. The results obtained are very promising given the extent of pose, expression and illumination variation in the video data used for experiments. JA - Pattern Recognition, 2004. ICPR 2004. Proceedings of the 17th International Conference on VL - 4 M3 - 10.1109/ICPR.2004.1333732 ER - TY - CONF T1 - Time and space optimization for processing groups of multi-dimensional scientific queries T2 - Proceedings of the 18th annual international conference on Supercomputing Y1 - 2004 A1 - Aryangat,Suresh A1 - Andrade,Henrique A1 - Sussman, Alan KW - multi-query optimization KW - Scientific databases AB - Data analysis applications in areas as diverse as remote sensing and telepathology require operating on and processing very large datasets. For such applications to execute efficiently, careful attention must be paid to the storage, retrieval, and manipulation of the datasets. This paper addresses the optimizations performed by a high performance database system that processes groups of data analysis requests for these applications, which we call queries. The system performs end-to-end processing of the requests, formulated as PostgreSQL declarative queries. The queries are converted into imperative descriptions, multiple imperative descriptions are merged into a single execution plan, the plan is optimized to decrease execution time via common compiler optimization techniques, and, finally, the plan is optimized to decrease memory consumption. The last two steps are experimentally shown to effectively reduc the amount of time required while conserving memory space as a group of queries is processed by the database. JA - Proceedings of the 18th annual international conference on Supercomputing T3 - ICS '04 PB - ACM CY - New York, NY, USA SN - 1-58113-839-3 UR - http://doi.acm.org/10.1145/1006209.1006224 M3 - 10.1145/1006209.1006224 ER - TY - CONF T1 - Utilizing volatile external information during planning T2 - Proceedings of the European Conference on Artificial Intelligence (ECAI) Y1 - 2004 A1 - Au,T. C A1 - Nau, Dana S. A1 - V.S. Subrahmanian JA - Proceedings of the European Conference on Artificial Intelligence (ECAI) ER - TY - JOUR T1 - Viable but Nonculturable Vibrio Cholerae O1 in the Aquatic Environment of Argentina JF - Applied and Environmental MicrobiologyAppl. Environ. Microbiol. Y1 - 2004 A1 - Binsztein,Norma A1 - Costagliola,Marcela C. A1 - Pichel,Mariana A1 - Jurquiza,Verónica A1 - Ramírez,Fernando C. A1 - Akselman,Rut A1 - Vacchino,Marta A1 - Huq,Anwarul A1 - Rita R Colwell AB - In Argentina, as in other countries of Latin America, cholera has occurred in an epidemic pattern. Vibrio cholerae O1 is native to the aquatic environment, and it occurs in both culturable and viable but nonculturable (VNC) forms, the latter during interepidemic periods. This is the first report of the presence of VNC V. cholerae O1 in the estuarine and marine waters of the Río de la Plata and the Argentine shelf of the Atlantic Ocean, respectively. Employing immunofluorescence and PCR methods, we were able to detect reservoirs of V. cholerae O1 carrying the virulence-associated genes ctxA and tcpA. The VNC forms of V. cholerae O1 were identified in samples of water, phytoplankton, and zooplankton; the latter organisms were mainly the copepods Acartia tonsa, Diaptomus sp., Paracalanus crassirostris, and Paracalanus parvus. We found that under favorable conditions, the VNC form of V. cholerae can revert to the pathogenic, transmissible state. We concluded that V. cholerae O1 is a resident of Argentinean waters, as has been shown to be the case in other geographic regions of the world. VL - 70 SN - 0099-2240, 1098-5336 UR - http://aem.asm.org/content/70/12/7481 CP - 12 M3 - 10.1128/AEM.70.12.7481-7486.2004 ER - TY - CONF T1 - Window-based, discontinuity preserving stereo T2 - Computer Vision and Pattern Recognition, 2004. CVPR 2004. Proceedings of the 2004 IEEE Computer Society Conference on Y1 - 2004 A1 - Agrawal,M. A1 - Davis, Larry S. KW - algorithm; KW - approach; KW - based KW - cuts; KW - dense KW - discontinuity KW - global KW - graph KW - image KW - local KW - MATCHING KW - matching; KW - minimisation; KW - optimization; KW - Pixel KW - preserving KW - processing; KW - stereo KW - theory; KW - window AB - Traditionally, the problem of stereo matching has been addressed either by a local window-based approach or a dense pixel-based approach using global optimization. In this paper we present an algorithm which combines window-based local matching into a global optimization framework. Our local matching algorithm assumes that local windows can have at most two disparities. Under this assumption, the local matching can be performed very efficiently using graph cuts. The global matching is formulated as minimization of an energy term that takes into account the matching constraints induced by the local stereo algorithm. Fast, approximate minimization of this energy is achieved through graph cuts. The key feature of our algorithm is that it preserves discontinuities both during the local as well as global matching phase. JA - Computer Vision and Pattern Recognition, 2004. CVPR 2004. Proceedings of the 2004 IEEE Computer Society Conference on VL - 1 M3 - 10.1109/CVPR.2004.1315015 ER - TY - JOUR T1 - 2003 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics October 19-22, 2003, New Paltz. NY JF - 2003 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics: October 19-22, 2003, Mohonk Mountain House, New Paltz, NY, USA Y1 - 2003 A1 - Adams,N. A1 - EssI,G. A1 - Makino,S. A1 - Martens,A.A.C.F.W.L. A1 - Algazi,R. A1 - Fellers,M. A1 - Martin,R. A1 - Avendano,C. A1 - Fielder,L. A1 - Mellody,M. A1 - others ER - TY - JOUR T1 - A 4-Year Study of the Epidemiology of Vibrio Cholerae in Four Rural Areas of Bangladesh JF - Journal of Infectious DiseasesJ Infect Dis. Y1 - 2003 A1 - Sack,R. Bradley A1 - Siddique,A. Kasem A1 - Longini,Ira M. A1 - Nizam,Azhar A1 - Yunus,Md A1 - M. Sirajul Islam A1 - Morris,Jr A1 - Ali,Afsar A1 - Huq,Anwar A1 - Nair,G. Balakrish A1 - Qadri,Firdausi A1 - Faruque,Shah M. A1 - Sack,David A. A1 - Rita R Colwell AB - How Vibrio cholerae spreads around the world and what determines its seasonal peaks in endemic areas are not known. These features of cholera have been hypothesized to be primarily the result of environmental factors associated with aquatic habitats that can now be identified. Since 1997, fortnightly surveillance in 4 widely separated geographic locations in Bangladesh has been performed to identify patients with cholera and to collect environmental data. A total of 5670 patients (53% <5 years of age) have been studied; 14.3% had cholera (10.4% due to V. cholerae O1 El Tor, 3.8% due to O139). Both serogroups were found in all locations; outbreaks were seasonal and often occurred simultaneously. Water-use patterns showed that bathing and washing clothes in tube-well water was significantly protective in two of the sites. These data will be correlated with environmental factors, to develop a model for prediction of cholera outbreaks VL - 187 SN - 0022-1899, 1537-6613 UR - http://jid.oxfordjournals.org/content/187/1/96 CP - 1 M3 - 10.1086/345865 ER - TY - JOUR T1 - An Analysis of the Layer 2 Handoff costs in Wireless Local Area Networks JF - ACM Computer Communications Review Y1 - 2003 A1 - Mishra,A. A1 - Shin,M. H. A1 - Arbaugh, William A. VL - 33 CP - 2 ER - TY - CHAP T1 - Approximation Algorithms for Channel Allocation Problems in Broadcast Networks T2 - Approximation, Randomization, and Combinatorial Optimization: Algorithms and Techniques Y1 - 2003 A1 - Gandhi,Rajiv A1 - Khuller, Samir A1 - Srinivasan, Aravind A1 - Wang,Nan ED - Arora,Sanjeev ED - Jansen,Klaus ED - Rolim,José ED - Sahai,Amit AB - We study two packing problems that arise in the area of dissemination-based information systems; a second theme is the study of distributed approximation algorithms. The problems considered have the property that the space occupied by a collection of objects together could be significantly less than the sum of the sizes of the individual objects. In the Channel Allocation Problem , there are users who request subsets of items. There are a fixed number of channels that can carry an arbitrary amount of information. Each user must get all of the requested items from one channel, i.e., all the data items of each request must be broadcast on some channel. The load on any channel is the number of items that are broadcast on that channel; the objective is to minimize the maximum load on any channel. We present approximation algorithms for this problem and also show that the problem is MAX-SNP hard. The second problem is the Edge Partitioning Problem addressed by Goldschmidt, Hochbaum, Levin, and Olinick ( Networks, 41:13-23, 2003 ). Each channel here can deliver information to at most k users, and we aim to minimize the total load on all channels. We present an O ( n⅓ )–approximation algorithm and also show that the algorithm can be made fully distributed with the same approximation guarantee; we also generalize to the case of hypergraphs. JA - Approximation, Randomization, and Combinatorial Optimization: Algorithms and Techniques T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2764 SN - 978-3-540-40770-6 UR - http://dx.doi.org/10.1007/978-3-540-45198-3_5 ER - TY - CONF T1 - Bootstrapping security associations for routing in mobile ad-hoc networks T2 - IEEE Global Telecommunications Conference, 2003. GLOBECOM '03 Y1 - 2003 A1 - Bobba,R. B A1 - Eschenauer,L. A1 - Gligor,V. A1 - Arbaugh, William A. KW - ad hoc networks KW - bootstrapping security association KW - Cryptographic protocols KW - dynamic source routing protocol KW - Fabrics KW - Intelligent networks KW - IP address KW - IP key KW - IP networks KW - Message authentication KW - mobile ad-hoc network KW - mobile radio KW - Protection KW - Public key KW - public key cryptography KW - routing layer security reliability KW - routing protocols KW - secure routing KW - Security KW - security service KW - statistically unique cryptographically verification KW - telecommunication security AB - To date, most solutions proposed for secure routing in mobile ad-hoc networks (MANETs), assume that secure associations between pairs of nodes can be established on-line; e.g., by a trusted third party, by distributed trust establishment. However, establishing such security associations, with or without trusted third parties, requires reliance on routing layer security. In this paper, we eliminate this apparent cyclic dependency between security services and secure routing in MANETs and show how to bootstrap security for the routing layer. We use the notion of statistically unique and cryptographically verifiable (SUCV) identifiers to implement a secure binding between IP addresses and keys that is independent of any trusted security service. We illustrate our solution with the dynamic source routing (DSR) protocol and compare it with other solutions for secure routing. JA - IEEE Global Telecommunications Conference, 2003. GLOBECOM '03 PB - IEEE VL - 3 SN - 0-7803-7974-8 M3 - 10.1109/GLOCOM.2003.1258490 ER - TY - CONF T1 - Camera calibration using spheres: a semi-definite programming approach T2 - Computer Vision, 2003. Proceedings. Ninth IEEE International Conference on Y1 - 2003 A1 - Agrawal,M. A1 - Davis, Larry S. KW - 3D KW - algorithms;calibration;cameras;computer KW - approach;sphere KW - calibration;camera KW - contours;semidefinite KW - extraction; KW - field;ellipse;intrinsic KW - location;spheres;vision KW - networks;common KW - parameters;occluding KW - Programming KW - target;camera KW - view KW - vision;feature AB - Vision algorithms utilizing camera networks with a common field of view are becoming increasingly feasible and important. Calibration of such camera networks is a challenging and cumbersome task. The current approaches for calibration using planes or a known 3D target may not be feasible as these objects may not be simultaneously visible in all the cameras. In this paper, we present a new algorithm to calibrate cameras using occluding contours of spheres. In general, an occluding contour of a sphere projects to an ellipse in the image. Our algorithm uses the projection of the occluding contours of three spheres and solves for the intrinsic parameters and the locations of the spheres. The problem is formulated in the dual space and the parameters are solved for optimally and efficiently using semidefinite programming. The technique is flexible, accurate and easy to use. In addition, since the contour of a sphere is simultaneously visible in all the cameras, our approach can greatly simplify calibration of multiple cameras with a common field of view. Experimental results from computer simulated data and real world data, both for a single camera and multiple cameras, are presented. JA - Computer Vision, 2003. Proceedings. Ninth IEEE International Conference on M3 - 10.1109/ICCV.2003.1238428 ER - TY - CONF T1 - Checking and inferring local non-aliasing T2 - ACM SIGPLAN Notices Y1 - 2003 A1 - Aiken,A. A1 - Foster, Jeffrey S. A1 - Kodumal,J. A1 - Terauchi,T. JA - ACM SIGPLAN Notices VL - 38 ER - TY - JOUR T1 - Complete camera calibration using spheres: Dual space approach JF - IEEE Y1 - 2003 A1 - Agrawal,M. A1 - Davis, Larry S. AB - Camera calibration is a fundamental problem in computer vision and photogrammetry. We present a new algorithmto calibrate cameras using spheres. In general, an occluding contour of a sphere projects to an ellipse in the image. Our algorithm uses the projection of the occluding contours of three spheres and solves for the intrinsic parameters and the locations of the spheres. The problem is formulated in the dual space and the parameters are solved for optimally and efficiently using semi-definite programming. The technique is flexible, accurate and easy to use. In addition, it can be used to simultaneously calibrate multiple cameras with a common field of view. Experimen- tal results from computer simulated data and real world data, both for a single camera and multiple cameras, are presented. VL - 206 ER - TY - JOUR T1 - Computational video JF - The Visual Computer Y1 - 2003 A1 - Aloimonos, J. VL - 19 CP - 6 ER - TY - JOUR T1 - The dangers of mitigating security design flaws: a wireless case study JF - IEEE Security & Privacy Y1 - 2003 A1 - Petroni,N. L. A1 - Arbaugh, William A. KW - Communication system security KW - computer security KW - cryptography KW - design flaw mitigation KW - Dictionaries KW - legacy equipment KW - privacy KW - Protection KW - Protocols KW - security design flaws KW - security of data KW - synchronous active attack KW - telecommunication security KW - Telecommunication traffic KW - wired equivalent privacy protocol KW - Wireless LAN KW - wireless local area networks KW - Wireless networks AB - Mitigating design flaws often provides the only means to protect legacy equipment, particularly in wireless local area networks. A synchronous active attack against the wired equivalent privacy protocol demonstrates how mitigating one flaw or attack can facilitate another. VL - 1 SN - 1540-7993 CP - 1 M3 - 10.1109/MSECP.2003.1176993 ER - TY - RPRT T1 - Domain Tuning of Bilingual Lexicons for MT Y1 - 2003 A1 - Ayan,Necip F A1 - Dorr, Bonnie J A1 - Kolak,Okan KW - *DICTIONARIES KW - *FOREIGN LANGUAGES KW - accuracy KW - BILINGUAL LEXICONS KW - DOCUMENTS KW - linguistics KW - Vocabulary AB - Our overall objective is to translate a domain-specific document in a foreign language (in this case, Chinese) to English. Using automatically induced domain-specific, comparable documents and language-independent clustering, we apply domain-tuning techniques to a bilingual lexicon for downstream translation of the input document to English. We will describe our domain-tuning technique and demonstrate its effectiveness by comparing our results to manually constructed domain-specific vocabulary. Our coverage/accuracy experiments indicate that domain-tuned lexicons achieve 88/% precision and 66/% recall. We also ran a Bleu experiment to compare our domain-tuned version to its un-tuned counterpart in an IR Ni-style NIT system. Our domain-tuned lexicons brought about an improvement in the Blen scores: 9.4/% higher than a system trained on a uniformly- weighted dictionary and 275/% higher than a system trained on no dictionary at all. PB - Instititue for Advanced Computer Studies, Univ of Maryland, College Park UR - http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA455197 ER - TY - CONF T1 - Energy-efficient broadcast and multicast trees for reliable wireless communication T2 - Wireless Communications and Networking, 2003. WCNC 2003. 2003 IEEE Y1 - 2003 A1 - Banerjee,S. A1 - Misra,A. A1 - Yeo,Jihwang A1 - Agrawala, Ashok K. KW - broadcast KW - channels;multicast KW - communication;broadcast KW - communication;network KW - data KW - delivery KW - energy-efficient KW - layer;multicast KW - network KW - networks;network KW - networks;telecommunication KW - paths;multicast KW - rates;link KW - reliability; KW - topologies;wireless KW - topology;radio KW - trees;error KW - trees;multihop KW - wireless AB - We define energy-efficient broadband and multicast schemes for reliable communication in multi-hop wireless networks. Unlike previous techniques, the choice of neighbors in the broadband and multicast trees in these schemes, are based not only on the link distance, but also on the error rates associated with the link. Our schemes can be implemented using both positive and negative acknowledgement based reliable broadcast techniques in the link layer. Through simulations, we show that our scheme achieves up to 45% improvement over previous schemes on realistic 100-node network topologies. A positive acknowledgment based implementation is preferred. Our simulations show that the additional benefits of a positive acknowledgement based implementation is marginal (1-2%). Therefore a negative acknowledgement based implementation of our schemes is equally applicable in constructing energy-efficient reliable and multicast data delivery paths. JA - Wireless Communications and Networking, 2003. WCNC 2003. 2003 IEEE VL - 1 M3 - 10.1109/WCNC.2003.1200429 ER - TY - JOUR T1 - Evaluation Techniques Applied to Domain Tuning of MT Lexicons JF - Proceedings of the Workshop “Towards Systematizing MT Evaluation Y1 - 2003 A1 - Ayan,N.F. A1 - Dorr, Bonnie J A1 - Kolak,O. AB - We describe a set of evaluation techniques applied to domain tuning of bilingual lexicons for machine translation.Our overall objective is to translate a domain-specific document in a foreign language (in this case, Chinese) to En- glish. First, we perform an intrinsic evaluation of the effectiveness of our domain-tuning techniques by comparing our domain-tuned lexicon to a manually constructed domain-specific bilingual termlist. Our results indicate that we achieve 66% recall and 95% precision with respect to a human-derived gold standard. Next, an extrinsic evaluation demonstrates that our domain-tuned lexicon improves the Bleu scores 50% over a statistical system—with a smaller improvement when the system is trained on a uniformly-weighted dictionary. VL - 27 ER - TY - CONF T1 - Exploiting Functional Decomposition for Efficient Parallel Processing of Multiple Data Analysis Queries T2 - Parallel and Distributed Processing Symposium, International Y1 - 2003 A1 - Andrade,Henrique A1 - Kurc,Tahsin A1 - Sussman, Alan A1 - Saltz,Joel AB - Reuse is a powerful method for increasing system performance. In this paper, we examine functional decomposition for improving data and computation reuse and, therefore, overall query execution performance in the context of data analysis applications. Additionally, we look at the performance effects of using various projection primitives that make it possible to transform intermediate results generated by a query so that they can be reused by a new query. A satellite data analysis application is used to experimentally show the performance benefits achieved using functional decomposition and projection primitives. JA - Parallel and Distributed Processing Symposium, International PB - IEEE Computer Society CY - Los Alamitos, CA, USA M3 - http://doi.ieeecomputersociety.org/10.1109/IPDPS.2003.1213184 ER - TY - CONF T1 - Eye design in the plenoptic space of light rays T2 - Ninth IEEE International Conference on Computer Vision, 2003. Proceedings Y1 - 2003 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D ego-motion estimation KW - Assembly KW - B-splines KW - Camera design KW - CAMERAS KW - captured image KW - compound eyes KW - Computer vision KW - data mining KW - eye KW - eye-carrying organism KW - Eyes KW - filter optimization KW - image representation KW - image resolution KW - Information geometry KW - Laboratories KW - light field reconstruction KW - light gathering power KW - light rays KW - mixed spherical-Cartesian coordinate system KW - Motion estimation KW - natural evolution process KW - natural eye designs KW - natural image statistics KW - optical nanotechnology KW - Optical signal processing KW - optimal eye design mathematical criteria KW - Organisms KW - plenoptic image formation KW - plenoptic space KW - plenoptic video geometry KW - sampling operators KW - sensory ecology KW - Signal design KW - Signal processing KW - signal processing framework KW - signal processing tool KW - square-summable sequences KW - visual acuity AB - Natural eye designs are optimized with regard to the tasks the eye-carrying organism has to perform for survival. This optimization has been performed by the process of natural evolution over many millions of years. Every eye captures a subset of the space of light rays. The information contained in this subset and the accuracy to which the eye can extract the necessary information determines an upper limit on how well an organism can perform a given task. In this work we propose a new methodology for camera design. By interpreting eyes as sample patterns in light ray space we can phrase the problem of eye design in a signal processing framework. This allows us to develop mathematical criteria for optimal eye design, which in turn enables us to build the best eye for a given task without the trial and error phase of natural evolution. The principle is evaluated on the task of 3D ego-motion estimation. JA - Ninth IEEE International Conference on Computer Vision, 2003. Proceedings PB - IEEE SN - 0-7695-1950-4 M3 - 10.1109/ICCV.2003.1238623 ER - TY - CONF T1 - Interpolation over light fields with applications in computer graphics T2 - Proceedings of the Fifth Workshop on Algorithm Engineering and Experiments Y1 - 2003 A1 - Atalay,F. B A1 - Mount, Dave JA - Proceedings of the Fifth Workshop on Algorithm Engineering and Experiments ER - TY - CONF T1 - Kernel snakes: non-parametric active contour models T2 - IEEE International Conference on Systems, Man and Cybernetics, 2003 Y1 - 2003 A1 - Abd-Almageed, Wael A1 - Smith,C.E. A1 - Ramadan,S. KW - Active contours KW - Artificial intelligence KW - Bayes methods KW - Bayesian decision theory KW - Bayesian methods KW - decision theory KW - Deformable models KW - Image edge detection KW - Image segmentation KW - Intelligent robots KW - Kernel KW - kernel snakes KW - Laboratories KW - multicolored target tracking KW - nonparametric active contour models KW - nonparametric generalized formulation KW - nonparametric model KW - nonparametric statistics KW - nonparametric techniques KW - real time performance KW - Robot vision systems KW - statistical pressure snakes KW - target tracking AB - In this paper, a new non-parametric generalized formulation to statistical pressure snakes is presented. We discuss the shortcomings of the traditional pressure snakes. We then introduce a new generic pressure model that alleviates these shortcomings, based on the Bayesian decision theory. Non-parametric techniques are used to obtain the statistical models that drive the snake. We discuss the advantages of using the proposed non-parametric model compared to other parametric techniques. Multi-colored-target tracking is used to demonstrate the performance of the proposed approach. Experimental results show enhanced, real-time performance. JA - IEEE International Conference on Systems, Man and Cybernetics, 2003 PB - IEEE VL - 1 SN - 0-7803-7952-7 M3 - 10.1109/ICSMC.2003.1243822 ER - TY - JOUR T1 - Matrix Algorithms, Volume II: Eigensystems JF - Applied Mechanics Reviews Y1 - 2003 A1 - Stewart, G.W. A1 - Author A1 - Mahajan,A. A1 - Reviewer KW - algorithm theory KW - Eigenvalues and eigenfunctions KW - linear algebra KW - matrix algebra KW - reviews VL - 56 UR - http://link.aip.org/link/?AMR/56/B2/1 CP - 1 M3 - 10.1115/1.1523352 ER - TY - JOUR T1 - Measuring the effects of internet path faults on reactive routing JF - SIGMETRICS Perform. Eval. Rev. Y1 - 2003 A1 - Feamster, Nick A1 - Andersen,David G. A1 - Balakrishnan,Hari A1 - Kaashoek,M. Frans AB - Empirical evidence suggests that reactive routing systems improve resilience to Internet path failures. They detect and route around faulty paths based on measurements of path performance. This paper seeks to understand why and under what circumstances these techniques are effective.To do so, this paper correlates end-to-end active probing experiments, loss-triggered traceroutes of Internet paths, and BGP routing messages. These correlations shed light on three questions about Internet path failures: (1) Where do failures appear? (2) How long do they last? (3) How do they correlate with BGP routing instability?Data collected over 13 months from an Internet testbed of 31 topologically diverse hosts suggests that most path failures last less than fifteen minutes. Failures that appear in the network core correlate better with BGP instability than failures that appear close to end hosts. On average, most failures precede BGP messages by about four minutes, but there is often increased BGP traffic both before and after failures. Our findings suggest that reactive routing is most effective between hosts that have multiple connections to the Internet. The data set also suggests that passive observations of BGP routing messages could be used to predict about 20% of impending failures, allowing re-routing systems to react more quickly to failures. VL - 31 SN - 0163-5999 UR - http://doi.acm.org/10.1145/885651.781043 CP - 1 M3 - 10.1145/885651.781043 ER - TY - CONF T1 - New eyes for robotics T2 - 2003 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2003. (IROS 2003). Proceedings Y1 - 2003 A1 - Baker, P. A1 - Ogale, A. S A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion estimation KW - Argus eye KW - array signal processing KW - Birds KW - Calibration KW - CAMERAS KW - Control systems KW - Eyes KW - geometric configuration KW - imaging KW - imaging system KW - Layout KW - Motion estimation KW - multiple stereo configurations KW - Robot kinematics KW - robot vision KW - Robot vision systems KW - ROBOTICS KW - Robotics and automation KW - SHAPE KW - shape models AB - This paper describes an imaging system that has been designed to facilitate robotic tasks of motion. The system consists of a number of cameras in a network arranged so that they sample different parts of the visual sphere. This geometric configuration has provable advantages compared to small field of view cameras for the estimation of the system's own motion and consequently the estimation of shape models from the individual cameras. The reason is that inherent ambiguities of confusion between translation and rotation disappear. Pairs of cameras may also be arranged in multiple stereo configurations which provide additional advantages for segmentation. Algorithms for the calibration of the system and the 3D motion estimation are provided. JA - 2003 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2003. (IROS 2003). Proceedings PB - IEEE VL - 1 SN - 0-7803-7860-1 M3 - 10.1109/IROS.2003.1250761 ER - TY - CONF T1 - Non-parametric expectation maximization: a learning automata approach T2 - IEEE International Conference on Systems, Man and Cybernetics, 2003 Y1 - 2003 A1 - Abd-Almageed, Wael A1 - El-Osery,A. A1 - Smith,C.E. KW - Automatic speech recognition KW - bivariate simulation data KW - Computational modeling KW - Computer vision KW - Density functional theory KW - expectation maximization technique KW - learning automata KW - mixture parameters estimation KW - nonparametric expectation maximization KW - nonparametric statistics KW - optimisation KW - parameter estimation KW - Parzen Window KW - PDF KW - probability KW - probability density function KW - Speech processing KW - Speech recognition KW - stochastic learning automata KW - Stochastic processes KW - stochastic technique AB - The famous expectation maximization technique suffers two major drawbacks. First, the number of components has to be specified apriori. Also, the expectation maximization is sensitive to initialization. In this paper, we present a new stochastic technique for estimating the mixture parameters. Parzen Window is used to estimate a discrete estimate of the PDF of the given data. Stochastic learning automata is then used to select the mixture parameters that minimize the distance between the discrete estimate of the PDF and the estimate of the expectation maximization. The validity of the proposed approach is verified using bivariate simulation data. JA - IEEE International Conference on Systems, Man and Cybernetics, 2003 PB - IEEE VL - 3 SN - 0-7803-7952-7 M3 - 10.1109/ICSMC.2003.1244347 ER - TY - CONF T1 - On-line computation of two types of structural relations in Japanese Y1 - 2003 A1 - Aoshima,S. A1 - Phillips,C. A1 - Weinberg, Amy ER - TY - JOUR T1 - Overlaying graph links on treemaps JF - IEEE Symposium on Information Visualization Conference Compendium (demonstration) Y1 - 2003 A1 - Fekete,J. D A1 - Wang,D. A1 - Dang,N. A1 - Aris,A. A1 - Plaisant, Catherine AB - Every graph can be decomposed into a tree structure plus a set ofremaining edges. We describe a visualization technique that displays the tree structure as a Treemap and the remaining edges as curved links overlaid on the Treemap. Link curves are designed to show where the link starts and where it ends without requiring an explicit arrow that would clutter the already dense visualization. This technique is effective for visualizing structures where the underlying tree has some meaning, such as Web sites or XML documents with cross-references. Graphic attributes of the links – such as color or thickness – can be used to represent attributes of the edges. Users can choose to see all links at once or only the links to and from the node or branch under the cursor. ER - TY - CONF T1 - Polydioptric camera design and 3D motion estimation T2 - 2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2003. Proceedings Y1 - 2003 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion estimation KW - Algorithm design and analysis KW - Application software KW - CAMERAS KW - Computer vision KW - Eyes KW - field-of-view camera KW - Image motion analysis KW - image sampling KW - image sensor KW - Image sensors KW - Layout KW - light ray KW - Motion estimation KW - multiperspective camera KW - optimal camera KW - optimal image formation KW - optimal sampling pattern KW - pinhole principle KW - polydioptric camera design KW - ray space KW - scene independent estimation KW - space structure analysis KW - stereo image processing KW - visual information processing AB - Most cameras used in computer vision applications are still based on the pinhole principle inspired by our own eyes. It has been found though that this is not necessarily the optimal image formation principle for processing visual information using a machine. We describe how to find the optimal camera for 3D motion estimation by analyzing the structure of the space formed by the light rays passing through a volume of space. Every camera corresponds to a sampling pattern in light ray space, thus the question of camera design can be rephrased as finding the optimal sampling pattern with regard to a given task. This framework suggests that large field-of-view multi-perspective (polydioptric) cameras are the optimal image sensors for 3D motion estimation. We conclude by proposing design principles for polydioptric cameras and describe an algorithm for such a camera that estimates its 3D motion in a scene independent and robust manner. JA - 2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2003. Proceedings PB - IEEE VL - 2 SN - 0-7695-1900-8 M3 - 10.1109/CVPR.2003.1211483 ER - TY - JOUR T1 - Quantifying the causes of path inflation JF - Topology Y1 - 2003 A1 - Spring, Neil A1 - Mahajan,R. A1 - Anderson,T. VL - 100 ER - TY - JOUR T1 - Random doping-induced fluctuations of subthreshold characteristics in MOSFET devices JF - Solid-State Electronics Y1 - 2003 A1 - Andrei,Petru A1 - Mayergoyz, Issak D KW - Fluctuations KW - Mismatch KW - MOSFET KW - Sensitivity analysis KW - Statistics KW - Submicron devices AB - The random doping-induced fluctuations of subthreshold characteristics in MOSFET devices are analyzed. A technique for the computations of sensitivity coefficients and variances of subthreshold parameters is presented and applied to the computation of fluctuations of subthreshold current and gate-voltage swing. This technique is based on the linearization of transport equations with respect to the fluctuating quantities. It is computationally much more efficient than purely “statistical” methods (Monte-Carlo methods) that are based on the simulations of a large number of devices with different doping realizations. The numerical implementation of this technique is discussed and numerous computational results are presented. VL - 47 SN - 0038-1101 UR - http://www.sciencedirect.com/science/article/pii/S0038110103002363 CP - 11 M3 - 10.1016/S0038-1101(03)00236-3 ER - TY - JOUR T1 - Rapid porting of DUSTer to Hindi JF - ACM Transactions on Asian Language Information Processing (TALIP) Y1 - 2003 A1 - Dorr, Bonnie J A1 - Ayan,Necip Fazil A1 - Habash,Nizar A1 - Madnani,Nitin A1 - Hwa,Rebecca KW - Divergences KW - Machine translation AB - The frequent occurrence of divergences—structural differences between languages---presents a great challenge for statistical word-level alignment and machine translation. This paper describes the adaptation of DUSTer, a divergence unraveling package, to Hindi during the DARPA TIDES-2003 Surprise Language Exercise. We show that it is possible to port DUSTer to Hindi in under 3 days. VL - 2 SN - 1530-0226 UR - http://doi.acm.org/10.1145/974740.974744 CP - 2 M3 - 10.1145/974740.974744 ER - TY - BOOK T1 - Real 802.11 Security: Wi-Fi Protected Access and 802.11 i, 480 pages Y1 - 2003 A1 - Edney,J. A1 - Arbaugh, William A. PB - Addison Wesley ER - TY - JOUR T1 - Reduction of Cholera in Bangladeshi Villages by Simple Filtration JF - Proceedings of the National Academy of SciencesPNAS Y1 - 2003 A1 - Rita R Colwell A1 - Huq,Anwar A1 - M. Sirajul Islam A1 - K. M. A. Aziz A1 - Yunus,M. A1 - N. Huda Khan A1 - A. Mahmud A1 - Sack,R. Bradley A1 - Nair,G. B. A1 - J. Chakraborty A1 - Sack,David A. A1 - E. Russek-Cohen AB - Based on results of ecological studies demonstrating that Vibrio cholerae, the etiological agent of epidemic cholera, is commensal to zooplankton, notably copepods, a simple filtration procedure was developed whereby zooplankton, most phytoplankton, and particulates >20 μm were removed from water before use. Effective deployment of this filtration procedure, from September 1999 through July 2002 in 65 villages of rural Bangladesh, of which the total population for the entire study comprised ≈133,000 individuals, yielded a 48% reduction in cholera (P < 0.005) compared with the control. VL - 100 SN - 0027-8424, 1091-6490 UR - http://www.pnas.org/content/100/3/1051 CP - 3 M3 - 10.1073/pnas.0237386100 ER - TY - CONF T1 - Scriptroute: A public Internet measurement facility T2 - Proceedings of the 4th conference on USENIX Symposium on Internet Technologies and Systems-Volume 4 Y1 - 2003 A1 - Spring, Neil A1 - Wetherall,D. A1 - Anderson,T. JA - Proceedings of the 4th conference on USENIX Symposium on Internet Technologies and Systems-Volume 4 ER - TY - CONF T1 - A secure service discovery protocol for MANET T2 - 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003 Y1 - 2003 A1 - Yuan Yuan A1 - Arbaugh, William A. KW - ad hoc networks KW - centralized administration KW - Computer architecture KW - Computer science KW - dynamic service discovery infrastructure KW - Educational institutions KW - MANET KW - Manuals KW - mobile ad hoc network KW - Mobile ad hoc networks KW - Mobile computing KW - mobile radio KW - noninfrastructure network KW - Pervasive computing KW - Protocols KW - routing protocols KW - secure service discovery protocol KW - Security KW - service discovery techniques KW - service discovery technologies KW - telecommunication computing KW - telecommunication services KW - XML AB - Service discovery technologies are exploited to enable services to advertise their existence in a dynamic way, and can be discovered, configured and used by other devices with minimum manual efforts. It plays an essential role in future network scenarios especially with development of mobile ad hoc network (MANET) and emergence of pervasive computing. Because MANET allows these devices to communicate dynamically without fixed infrastructure and centralized administration, it gives rise to the challenges of the service discovery techniques. In this paper, we present a dynamic service discovery infrastructure that uses XML to describe services and match using the semantic content of service descriptions for MANET. We believe that the architecture we have designed is a necessary component of service discovery in non-infrastructure network by further exploring the secure and performance issues of this infrastructure. JA - 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003 PB - IEEE VL - 1 SN - 0-7803-7822-9 M3 - 10.1109/PIMRC.2003.1264322 ER - TY - JOUR T1 - SHOP2: An HTN planning system JF - J. Artif. Intell. Res. (JAIR) Y1 - 2003 A1 - Nau, Dana S. A1 - Au,T. C A1 - Ilghami,O. A1 - Kuter,U. A1 - Murdock,J. W. A1 - Wu,D. A1 - Yaman,F. AB - The SHOP2 planning system received one of the awards for distinguished performance in the 2002 International Planning Competition. This paper describes the features of SHOP2 which enabled it to excel in the competition, especially those aspects of SHOP2 that deal with temporal and metric planning domains. VL - 20 UR - https://www.aaai.org/Papers/JAIR/Vol20/JAIR-2013.pdf ER - TY - BOOK T1 - Special section on perceptual organization in computer vision Y1 - 2003 A1 - Jacobs, David W. A1 - Lindenbaum,M. A1 - August,J. A1 - Zucker,SW A1 - Ben-Shahar,O. A1 - Zucker,SW A1 - Tuytelaars,T. A1 - Turina,A. A1 - Van Gool,L. A1 - Mahamud,S. PB - IEEE Computer Society ER - TY - CONF T1 - Toward secure key distribution in truly ad-hoc networks T2 - Applications and the Internet Workshops, 2003. Proceedings. 2003 Symposium on Y1 - 2003 A1 - Khalili,A. A1 - Katz, Jonathan A1 - Arbaugh, William A. KW - ad KW - ad-hoc KW - cryptography; KW - distribution; KW - hoc KW - identity-based KW - key KW - mobile KW - network KW - networks; KW - routing; KW - secure KW - security; KW - Telecommunication KW - threshold KW - wireless AB - Ad-hoc networks - and in particular wireless mobile ad-hoc networks $have unique characteristics and constraints that make traditional cryptographic mechanisms and assumptions inappropriate. In particular it may not be warranted to assume pre-existing shared secrets between members of the network or the presence of a common PKI. Thus, the issue of key distribution in ad-hoc networks represents an important problem. Unfortunately, this issue has been largely ignored; as an example, most protocols for secure ad-hoc routing assume that key distribution has already taken place. Traditional key distribution schemes either do not apply in an ad-hoc scenario or are not efficient enough for small, resource-constrained devices. We propose to combine efficient techniques from identity-based (ID-based) and threshold cryptography to provide a mechanism that enables flexible and efficient key distribution while respecting the constraints of ad-hoc networks. We also discuss the available mechanisms and their suitability for the proposed task. JA - Applications and the Internet Workshops, 2003. Proceedings. 2003 Symposium on M3 - 10.1109/SAINTW.2003.1210183 ER - TY - CONF T1 - Towards domain-independent, task-oriented, conversational adequacy T2 - INTERNATIONAL JOINT CONFERENCE ON ARTIFICIAL IN℡LIGENCE Y1 - 2003 A1 - Josyula,D. P A1 - Anderson,M. L A1 - Perlis, Don JA - INTERNATIONAL JOINT CONFERENCE ON ARTIFICIAL IN℡LIGENCE VL - 18 ER - TY - JOUR T1 - Use of the SAND spatial browser for digital government applications JF - Commun. ACM Y1 - 2003 A1 - Samet, Hanan A1 - Alborzi,Houman A1 - Brabec,František A1 - Esperança,Claudio A1 - Hjaltason,Gísli R. A1 - Morgan,Frank A1 - Tanin,Egemen KW - GIS AB - Numerous federal agencies produce official statistics made accessible to ordinary citizens for searching and data retrieval. This is frequently done via the Internet through a Web browser interface. If this data is presented in textual format, it can often be searched and retrieved by such attributes as topic, responsible agency, keywords, or press release. However, if the data is of spatial nature, for example, in the form of a map, then using text-based queries is often too cumbersome for the intended audience. We describe the use of the SAND Spatial Browser to provide more power to users of these databases by enabling them to define and explore the specific spatial region of interest graphically. The SAND Spatial Browser allows users to form either purely spatial or mixed spatial/nonspatial queries intuitively, which can present information to users that might have been missed if only a textual interface was available. VL - 46 SN - 0001-0782 UR - http://doi.acm.org/10.1145/602421.602453 CP - 1 M3 - 10.1145/602421.602453 ER - TY - CONF T1 - User-level internet path diagnosis T2 - ACM SIGOPS Operating Systems Review Y1 - 2003 A1 - Mahajan,R. A1 - Spring, Neil A1 - Wetherall,D. A1 - Anderson,T. JA - ACM SIGOPS Operating Systems Review VL - 37 ER - TY - JOUR T1 - WLAN problems and solutions JF - Communications of the ACM Y1 - 2003 A1 - Housley,R. A1 - Arbaugh, William A. VL - 46 CP - 5 ER - TY - JOUR T1 - AAAI 2002 Workshops JF - AI Magazine Y1 - 2002 A1 - Blake,Brian A1 - Haigh,Karen A1 - Hexmoor,Henry A1 - Falcone,Rino A1 - Soh,Leen-Kiat A1 - Baral,Chitta A1 - McIlraith,Sheila A1 - Gmytrasiewicz,Piotr A1 - Parsons,Simon A1 - Malaka,Rainer A1 - Krueger,Antonio A1 - Bouquet,Paolo A1 - Smart,Bill A1 - Kurumantani,Koichi A1 - Pease,Adam A1 - Brenner,Michael A1 - desJardins, Marie A1 - Junker,Ulrich A1 - Delgrande,Jim A1 - Doyle,Jon A1 - Rossi,Francesca A1 - Schaub,Torsten A1 - Gomes,Carla A1 - Walsh,Toby A1 - Guo,Haipeng A1 - Horvitz,Eric J A1 - Ide,Nancy A1 - Welty,Chris A1 - Anger,Frank D A1 - Guegen,Hans W A1 - Ligozat,Gerald VL - 23 SN - 0738-4602 UR - http://www.aaai.org/ojs/index.php/aimagazine/article/viewArticle/1678 CP - 4 M3 - 10.1609/aimag.v23i4.1678 ER - TY - CONF T1 - Active Proxy-G: Optimizing the query execution process in the Grid T2 - Proceedings of the 2002 ACM/IEEE conference on Supercomputing Y1 - 2002 A1 - Andrade,H. A1 - Kurc, T. A1 - Sussman, Alan A1 - Saltz, J. JA - Proceedings of the 2002 ACM/IEEE conference on Supercomputing ER - TY - JOUR T1 - AD (Attacker Defender) Game JF - Technical Reports from UMIACS, UMIACS-TR-2001-45 Y1 - 2002 A1 - Kochut,Andrzej A1 - Agrawala, Ashok K. A1 - Larsen,Ronald L A1 - A. Udaya Shankar KW - Technical Report AB - Information Dynamics is a framework for agent-based systems that givesa central position to the role of information, time, and the value of information. We illustrate system design in the Information Dynamics Framework by developing an intelligence game called AD involving attackers, defenders and targets operating in some space of locations. The goal of the attackers is to destroy all targets. Target destruction takes place when the number of attackers in the target's neighborhood exceeds the number of defenders in this neighborhood by a value WINNING_DIFFERENCE. The goal of defenders is to prevent attackers from achieving their goal. (Also UMIACS-TR-2001-45) UR - http://drum.lib.umd.edu/handle/1903/1142 ER - TY - JOUR T1 - Algorithmic issues in modeling motion JF - ACM Comput. Surv. Y1 - 2002 A1 - Agarwal,Pankaj K. A1 - Guibas,Leonidas J. A1 - Edelsbrunner,Herbert A1 - Erickson,Jeff A1 - Isard,Michael A1 - Har-Peled,Sariel A1 - Hershberger,John A1 - Jensen,Christian A1 - Kavraki,Lydia A1 - Koehl,Patrice A1 - Lin,Ming A1 - Manocha,Dinesh A1 - Metaxas,Dimitris A1 - Mirtich,Brian A1 - Mount, Dave A1 - Muthukrishnan,S. A1 - Pai,Dinesh A1 - Sacks,Elisha A1 - Snoeyink,Jack A1 - Suri,Subhash A1 - Wolefson,Ouri KW - computational geometry KW - Computer vision KW - mobile networks KW - modeling KW - molecular biology KW - motion modeling KW - physical simulation KW - robotoics KW - spatio-temporal databases AB - This article is a survey of research areas in which motion plays a pivotal role. The aim of the article is to review current approaches to modeling motion together with related data structures and algorithms, and to summarize the challenges that lie ahead in producing a more unified theory of motion representation that would be useful across several disciplines. VL - 34 SN - 0360-0300 UR - http://doi.acm.org/10.1145/592642.592647 CP - 4 M3 - 10.1145/592642.592647 ER - TY - CONF T1 - ALLI: An Information Integration System Based on Active Logic Framework T2 - Proceedings of the Third International Conference on Management Information Systems, Greece Y1 - 2002 A1 - Barfourosh,A. A. A1 - Nezhad,H. R.M A1 - Anderson,M. A1 - Perlis, Don JA - Proceedings of the Third International Conference on Management Information Systems, Greece ER - TY - JOUR T1 - Approximating the head-related transfer function using simple geometric models of the head and torso JF - The Journal of the Acoustical Society of America Y1 - 2002 A1 - Algazi,V. R A1 - Duda,R. O A1 - Duraiswami, Ramani A1 - Gumerov, Nail A. A1 - Tang,Z. VL - 112 ER - TY - CONF T1 - Argument structure saturation in a constraint based model Y1 - 2002 A1 - Drury,J. A1 - Resnik, Philip A1 - Weinberg, Amy A1 - Gennari,S. A1 - Aoshima,S. UR - http://cognet.mit.edu/library/conferences/paper?paper_id=55048 ER - TY - CHAP T1 - An Augmented Visual Query Mechanism for Finding Patterns in Time Series Data T2 - Flexible Query Answering SystemsFlexible Query Answering Systems Y1 - 2002 A1 - Keogh,Eamonn A1 - Hochheiser,Harry A1 - Shneiderman, Ben ED - Carbonell,Jaime ED - Siekmann,Jörg ED - Andreasen,Troels ED - Christiansen,Henning ED - Motro,Amihai ED - Legind Larsen,Henrik AB - Relatively few query tools exist for data exploration and pattern identification in time series data sets. In previous work we introduced Timeboxes . Timeboxes are rectangular, direct-manipulation queries for studying time-series datasets. We demonstrated how Timeboxes can be used to support interactive exploration via dynamic queries, along with overviews of query results and drag-and-drop support for query-by-example. In this paper, we extend our work by introducing Variable Time Timeboxes (VTT). VTTs are a natural generalization of Timeboxes, which permit the specification of queries that allow a degree of uncertainty in the time axis. We carefully motivate the need for these more expressive queries, and demonstrate the utility of our approach on several data sets. JA - Flexible Query Answering SystemsFlexible Query Answering Systems T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2522 SN - 978-3-540-00074-7 UR - http://dx.doi.org/10.1007/3-540-36109-X_19 ER - TY - JOUR T1 - Bias in visual motion processes: A theory predicting illusions JF - Statistical Methods in Video Processing.(in conjunction with European Conference on Computer Vision) Y1 - 2002 A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Malm,H. AB - The first step in the interpretation of video sequences is theestimation of spatio-temporal image representations, that is the image motion or the correspondence of points or lines. Noise in the data, however, causes a serious problem for their estimation; in particular, it causes bias. As a result the location of image points, the orientation of image lines and the length and orientation of image motion vectors are esti- mated erroneously. It is suggested that machine vision sys- tems processing video should include statistical procedures to alleviate the bias. However, complete correction in gen- eral does not appear to be feasible, and this provides an ex- planation for most well-known geometrical optical illusions, such as the café wall, the Zöllner, the Poggendorff illusion and other recently discovered illusions of movement. ER - TY - CONF T1 - On cache replacement policies for servicing mixed data intensive query workloads T2 - Proceedings of the 2nd Workshop on Caching, Coherence, and Consistency, held in conjunction with the 16th ACM International Conference on Supercomputing Y1 - 2002 A1 - Andrade,H. A1 - Kurc, T. A1 - Sussman, Alan A1 - Borovikov,E. A1 - Saltz, J. AB - When data analysis applications are employed in a multi-client environment, a data server must service multiple si- multaneous queries, each of which may employ complex user-defined data structures and operations on the data. It is then necessary to harness inter- and intra-query com- monalities and system resources to improve the performance of the data server. We have developed a framework and customizable middleware to enable reuse of intermediate and final results among queries, through an in-memory ac- tive semantic cache and user-defined transformation func- tions. Since resources such as processing power and mem- ory space are limited on the machine hosting the server, ef- fective scheduling of incoming queries and efficient cache replacement policies are challenging issues that must be ad- dressed. We have worked on the scheduling problem in ear- lier work, and in this paper we describe and evaluate several cache replacement policies. We present experimental eval- uation of the policies on a shared-memory parallel system using two applications from different application domains. JA - Proceedings of the 2nd Workshop on Caching, Coherence, and Consistency, held in conjunction with the 16th ACM International Conference on Supercomputing ER - TY - CONF T1 - CaMeL: Learning method preconditions for HTN planning Y1 - 2002 A1 - Ilghami,O. A1 - Nau, Dana S. A1 - Munoz-Avila,H. A1 - Aha,D. W. AB - A great challenge in using any planning system to solve real-world problems is the difficulty of acquiring the do- main knowledge that the system will need. We present a way to address part of this problem, in the context of Hierarchical Task Network (HTN) planning, by having the planning system incrementally learn conditions for HTN methods under expert supervision. We present a general formal framework for learning HTN methods, and a supervised learning algorithm, named CaMeL, based on this formalism. We present theoretical results about CaMeL’s soundness, completeness, and conver- gence properties. We also report experimental results about its speed of convergence under different condi- tions. The experimental results suggest that CaMeL has the potential to be useful in real-world applications. UR - https://www.aaai.org/Papers/AIPS/2002/AIPS02-014.pdf ER - TY - CONF T1 - Clustering and server selection using passive monitoring T2 - IEEE INFOCOM 2002. Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings Y1 - 2002 A1 - Andrews,M. A1 - Shepherd,B. A1 - Srinivasan, Aravind A1 - Winkler,P. A1 - Zane,F. KW - client assignment KW - client-server systems KW - clustering KW - content servers KW - Delay KW - distributed system KW - Educational institutions KW - Internet KW - IP addresses KW - Monitoring KW - network conditions KW - Network servers KW - Network topology KW - optimal content server KW - passive monitoring KW - server selection KW - Space technology KW - TCPIP KW - Transport protocols KW - Web pages KW - Web server KW - Webmapper AB - We consider the problem of client assignment in a distributed system of content servers. We present a system called Webmapper for clustering IP addresses and assigning each cluster to an optimal content server. The system is passive in that the only information it uses comes from monitoring the TCP connections between the clients and the servers. It is also flexible in that it makes no a priori assumptions about network topology and server placement and it can react quickly to changing network conditions. We present experimental results to evaluate the performance of Webmapper. JA - IEEE INFOCOM 2002. Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings PB - IEEE VL - 3 SN - 0-7803-7476-2 M3 - 10.1109/INFCOM.2002.1019425 ER - TY - CHAP T1 - On the Complexity of Plan Adaptation by Derivational Analogy in a Universal Classical Planning Framework T2 - Advances in Case-Based Reasoning Y1 - 2002 A1 - Au,Tsz-Chiu A1 - Muñoz-Avila,Héctor A1 - Nau, Dana S. ED - Craw,Susan ED - Preece,Alun KW - Computer science AB - In this paper we present an algorithm called DerUCP, which can be regarded as a general model for plan adaptation using Derivational Analogy. Using DerUCP, we show that previous results on the complexity of plan adaptation do not apply to Derivational Analogy. We also show that Derivational Analogy can potentially produce exponential reductions in the size of the search space generated by a planning system. JA - Advances in Case-Based Reasoning T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2416 SN - 978-3-540-44109-0 UR - http://www.springerlink.com/content/db2mr13j90mfrcaw/abstract/ ER - TY - CONF T1 - Contour migration: solving object ambiguity with shape-space visual guidance T2 - IEEE/RSJ International Conference on Intelligent Robots and Systems, 2002 Y1 - 2002 A1 - Abd-Almageed, Wael A1 - Smith,C.E. KW - Artificial intelligence KW - camera motion KW - CAMERAS KW - Computer vision KW - contour migration KW - Databases KW - edge detection KW - Intelligent robots KW - Laboratories KW - Machine vision KW - object ambiguity KW - Object recognition KW - pattern matching KW - Robot vision systems KW - servomechanisms KW - SHAPE KW - shape matching KW - shape-space visual guidance KW - silhouette matching KW - visual servoing AB - A fundamental problem in computer vision is the issue of shape ambiguity. Simply stated, a silhouette cannot uniquely identify an object or an object's classification since many unique objects can present identical occluding contours. This problem has no solution in the general case for a monocular vision system. This paper presents a method for disambiguating objects during silhouette matching using a visual servoing system. This method identifies the camera motion(s) that gives disambiguating views of the objects. These motions are identified through a new technique called contour migration. The occluding contour's shape is used to identify objects or object classes that are potential matches for that shape. A contour migration is then determined that disambiguates the possible matches by purposive viewpoint adjustment. The technique is demonstrated using an example set of objects. JA - IEEE/RSJ International Conference on Intelligent Robots and Systems, 2002 PB - IEEE VL - 1 SN - 0-7803-7398-7 M3 - 10.1109/IRDS.2002.1041410 ER - TY - JOUR T1 - Efficient Data Processing using Cross Layer Hints JF - Technical Reports from UMIACS, UMIACS-TR-2002-59 Y1 - 2002 A1 - Banerjee,Suman A1 - Agrawala, Ashok K. A1 - Kramer,Michael J KW - Technical Report AB - Conventional network stacks define a layered architecture, whereeach layer implements a set of services and exports a well-defined interface to be used by its immediate upper layer. A key design choice of the layered architecture has been to provide isolation between the functional modules of distinct layers. While such an architecture provides an useful abstraction for system development, the strict isolation of this layered architecture limits the flexibility of tailoring the behavior of the lower layers of the stack to the needs of the application. In this paper we define a new architecture, called X-Tags, which allows flexible interaction between layers for cooperative data processing without impacting the isolation property. In this architecture, applications use special tags to provide semantic hints for data processing to lower layers. We motivate the usefulness of this architecture by describing ts applicability to some emerging applications. UMIACS-TR-2002-59 UR - http://drum.lib.umd.edu/handle/1903/1211 ER - TY - CONF T1 - An experimental evaluation of linear and kernel-based methods for face recognition T2 - Applications of Computer Vision, 2002. (WACV 2002). Proceedings. Sixth IEEE Workshop on Y1 - 2002 A1 - Gupta, H. A1 - Agrawala, Ashok K. A1 - Pruthi, T. A1 - Shekhar, C. A1 - Chellapa, Rama KW - analysis; KW - classification; KW - component KW - discriminant KW - Face KW - image KW - Kernel KW - linear KW - Machine; KW - nearest KW - neighbor; KW - principal KW - recognition; KW - Support KW - vector AB - In this paper we present the results of a comparative study of linear and kernel-based methods for face recognition. The methods used for dimensionality reduction are Principal Component Analysis (PCA), Kernel Principal Component Analysis (KPCA), Linear Discriminant Analysis (LDA) and Kernel Discriminant Analysis (KDA). The methods used for classification are Nearest Neighbor (NN) and Support Vector Machine (SVM). In addition, these classification methods are applied on raw images to gauge the performance of these dimensionality reduction techniques. All experiments have been performed on images from UMIST Face Database. JA - Applications of Computer Vision, 2002. (WACV 2002). Proceedings. Sixth IEEE Workshop on M3 - 10.1109/ACV.2002.1182137 ER - TY - CONF T1 - Eye tracking using active deformable models T2 - Proc. of the IIIrd Indian Conference on Computer Vision, Graphics and Image Processing Y1 - 2002 A1 - Ramadan,S. A1 - Abd-Almageed, Wael A1 - Smith,C.E. JA - Proc. of the IIIrd Indian Conference on Computer Vision, Graphics and Image Processing ER - TY - CONF T1 - Eyes form eyes: New cameras for structure from motion T2 - Proceedings Workshop on Omnidirectional Vision (OMNIVIS) Y1 - 2002 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Proceedings Workshop on Omnidirectional Vision (OMNIVIS) ER - TY - CONF T1 - Eyes from eyes: new cameras for structure from motion T2 - Third Workshop on Omnidirectional Vision, 2002. Proceedings Y1 - 2002 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - Algorithm design and analysis KW - Camera design KW - CAMERAS KW - Design automation KW - differential stereo KW - Educational institutions KW - ego-motion estimation KW - Eyes KW - Geometrical optics KW - IMAGE PROCESSING KW - Layout KW - Motion estimation KW - observed scene KW - Optical films KW - polydioptric camera KW - RETINA AB - We investigate the relationship between camera design and the problem of recovering the motion and structure of a scene from video data. The visual information that could possibly be obtained is described by the plenoptic function. A camera can be viewed as a device that captures a subset of this function, that is, it measures some of the light rays in some part of the space. The information contained in the subset determines how difficult it is to solve subsequent interpretation processes. By examining the differential structure of the time varying plenoptic function we relate different known and new camera models to the spatiotemporal structure of the observed scene. This allows us to define a hierarchy of camera designs, where the order is determined by the stability and complexity of the computations necessary to estimate structure and motion. At the low end of this hierarchy is the standard planar pinhole camera for which the structure from motion problem is non-linear and ill-posed. At the high end is a new camera, which we call the full field of view polydioptric camera, for which the problem is linear and stable. In between are multiple-view cameras with large fields of view which we have built, as well as catadioptric panoramic sensors and other omni-directional cameras. We develop design suggestions for the polydioptric camera, and based upon this new design we propose a linear algorithm for ego-motion estimation, which in essence combines differential motion estimation with differential stereo. JA - Third Workshop on Omnidirectional Vision, 2002. Proceedings PB - IEEE SN - 0-7695-1629-7 M3 - 10.1109/OMNVIS.2002.1044486 ER - TY - JOUR T1 - Flow-sensitive type qualifiers JF - ACM SIGPLAN Notices Y1 - 2002 A1 - Foster, Jeffrey S. A1 - Terauchi,T. A1 - Aiken,A. VL - 37 CP - 5 ER - TY - JOUR T1 - Generating A Parsing Lexicon from an LCS-Based Lexicon JF - LREC 2002 Workshop Proceedings: Linguistic Knowledge Acquisition and Representation: Bootstrapping Annotated Language Data Y1 - 2002 A1 - Ayan,N.F. A1 - Dorr, Bonnie J AB - This paper describes a technique for generating parsing lexicons for a principle-based parser (Minipar). Our approach mapslexical entries in a large LCS-based repository of semantically classified verbs to their corresponding syntactic patterns. A by-product of this mapping is a lexicon that is directly usable in the Minipar system. We evaluate the accuracy and coverage of this lexicon using LDOCE syntactic codes as a gold standard. We show that this lexicon is comparable to the hand-generated Minipar lexicon (i.e., similar recall and precision values). In a later experiment, we automate the process of mapping between the LCS-based repository and syntactic patterns. The advantage of automating the process is that the same technique can be applied directly to lexicons we have for other languages, for example, Arabic, Chinese, and Spanish. ER - TY - RPRT T1 - Generating A Parsing Lexicon From Lexical-Conceptual Structure Y1 - 2002 A1 - Ayan,N.F. A1 - Dorr, Bonnie J AB - This paper describes the generation of a lexicon for a principle-based parser (Minipar[5,6]) using descriptions of verbs based on Lexical-Conceptual Structure (LCS [1,2]).1 We aim to determine how much syntactic information we can obtain from a semantic- based lexicon. More specifically, we aim to provide a general approach to projection of syntactic entries from semantic (language-independent) lexicons-and to test the effect of such lexicons on parser performance. Verbs are grouped together into classes-each denoted by an LCS representation adn the thematic grid. These are mapped systemat- ically into syntactic categories associated with entries in the Minipar parser. The main advantage of this LCS-to-syntax projection is language protability: We currently have LCS lexicons for English, Arabic, Spanish, and Chinese; thus, our LCS-projection ap- proach allows us to produce syntactic lexicons for parsing in each of these languages. For comparing the performance of the projection from the LCS to Minpar coes, we also generated the mappings for the codes of Longman's Directionary of Contemporary En- glish (LDOCE [8])-the most comprehensive online dictionary for syntactic categorization. Preliminary experiments indicate that our approach yields a categorization of verbs with 58% precision and 65% recall as measured against LDOCE-with an improved precision of 74% when redundancy is removed. The next section presents a brief description of each code set we use. In Section 3, we explain how we generated Minipar codes from LCS representation. Finally, Section 4, discusses our experiments and results. PB - Instititue for Advanced Computer Studies, Univ of Maryland, College Park ER - TY - JOUR T1 - Genome sequence and comparative analysis of the model rodent malaria parasite Plasmodium yoelii yoelii JF - Nature Y1 - 2002 A1 - Carlton,Jane M. A1 - Angiuoli,Samuel V A1 - Suh,Bernard B. A1 - Kooij,Taco W. A1 - Pertea,Mihaela A1 - Silva,Joana C. A1 - Ermolaeva,Maria D. A1 - Allen,Jonathan E A1 - Jeremy D Selengut A1 - Koo,Hean L. A1 - Peterson,Jeremy D. A1 - Pop, Mihai A1 - Kosack,Daniel S. A1 - Shumway,Martin F. A1 - Bidwell,Shelby L. A1 - Shallom,Shamira J. A1 - Aken,Susan E. van A1 - Riedmuller,Steven B. A1 - Feldblyum,Tamara V. A1 - Cho,Jennifer K. A1 - Quackenbush,John A1 - Sedegah,Martha A1 - Shoaibi,Azadeh A1 - Cummings,Leda M. A1 - Florens,Laurence A1 - Yates,John R. A1 - Raine,J. Dale A1 - Sinden,Robert E. A1 - Harris,Michael A. A1 - Cunningham,Deirdre A. A1 - Preiser,Peter R. A1 - Bergman,Lawrence W. A1 - Vaidya,Akhil B. A1 - Lin,Leo H. van A1 - Janse,Chris J. A1 - Waters,Andrew P. A1 - Smith,Hamilton O. A1 - White,Owen R. A1 - Salzberg,Steven L. A1 - Venter,J. Craig A1 - Fraser,Claire M. A1 - Hoffman,Stephen L. A1 - Gardner,Malcolm J. A1 - Carucci,Daniel J. AB - Species of malaria parasite that infect rodents have long been used as models for malaria disease research. Here we report the whole-genome shotgun sequence of one species, Plasmodium yoelii yoelii, and comparative studies with the genome of the human malaria parasite Plasmodium falciparum clone 3D7. A synteny map of 2,212 P. y. yoelii contiguous DNA sequences (contigs) aligned to 14 P. falciparum chromosomes reveals marked conservation of gene synteny within the body of each chromosome. Of about 5,300 P. falciparum genes, more than 3,300 P. y. yoelii orthologues of predominantly metabolic function were identified. Over 800 copies of a variant antigen gene located in subtelomeric regions were found. This is the first genome sequence of a model eukaryotic parasite, and it provides insight into the use of such systems in the modelling of Plasmodium biology and disease. VL - 419 SN - 0028-0836 UR - http://www.nature.com/nature/journal/v419/n6906/full/nature01099.html CP - 6906 M3 - 10.1038/nature01099 ER - TY - CONF T1 - Hidden Markov models for silhouette classification T2 - Automation Congress, 2002 Proceedings of the 5th Biannual World Y1 - 2002 A1 - Abd-Almageed, Wael A1 - Smith,C. KW - Computer vision KW - Feature extraction KW - Fourier transforms KW - hidden Markov models KW - HMM KW - image classification KW - Neural networks KW - object classification KW - Object recognition KW - parameter estimation KW - pattern recognition KW - Probability distribution KW - Shape measurement KW - silhouette classification KW - Wavelet transforms AB - In this paper, a new technique for object classification from silhouettes is presented. Hidden Markov models are used as a classification mechanism. Through a set of experiments, we show the validity of our approach and show its invariance under severe rotation conditions. Also, a comparison with other techniques that use hidden Markov models for object classification from silhouettes is presented. JA - Automation Congress, 2002 Proceedings of the 5th Biannual World PB - IEEE VL - 13 SN - 1-889335-18-5 M3 - 10.1109/WAC.2002.1049575 ER - TY - JOUR T1 - Identification of non-autonomous non-LTR retrotransposons in the genome of Trypanosoma cruzi JF - Molecular and Biochemical Parasitology Y1 - 2002 A1 - Bringaud,Frédéric A1 - García-Pérez,José Luis A1 - Heras,Sara R. A1 - Ghedin,Elodie A1 - El‐Sayed, Najib M. A1 - Andersson,Björn A1 - Baltz,Théo A1 - Lopez,Manuel C. KW - Ingi KW - L1Tc KW - Non-LTR retrotransposon KW - RIME KW - Trypanosoma brucei KW - Trypanosoma cruzi AB - As observed for most eukaryotic cells, trypanosomatids contains non-LTR retrotransposons randomly inserted in the nuclear genome. Autonomous retroelements which, code for their own transposition, have been characterized in Trypanosoma brucei (ingi) and Trypanosoma cruzi (L1Tc), whereas non-autonomous retroelements have only been characterized in T. brucei (RIME). Here, we have characterized in the genome of Trypanosoma cruzi four complete copies of a non-autonomous non-LTR retrotransposon, called NARTc. This 0.26 kb NARTc element has the characteristics of non-LTR retrotransposons: the presence a poly(dA) tail and of a short flanking duplicated motif. Analysis of the Genome Survey Sequence databases indicated that the Trypanosoma cruzi haploid genome contains about 140 NARTc copies and about twice as many L1Tc copies. Interestingly, the NARTc and L1Tc retroelements share, with the Trypanosoma brucei ingi and RIME retrotransposons, a common sequence (the first 45 bp with 91% identity), whereas the remaining sequences are very divergent. This suggests that these four trypanosome non-LTR retrotransposons were derived from the same common ancester and the sequence of their 5'-extremity may have a functional role. In addition, the genome of Leishmania major contains the same conserved motif present in the trypanosome retroelements, whicle no transposable elements have been detected so far in Leishmania sp. VL - 124 SN - 0166-6851 UR - http://www.sciencedirect.com/science/article/pii/S0166685102001676 CP - 1-2 M3 - 16/S0166-6851(02)00167-6 ER - TY - CONF T1 - Inferring link weights using end-to-end measurements T2 - Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment Y1 - 2002 A1 - Mahajan,Ratul A1 - Spring, Neil A1 - Wetherall,David A1 - Anderson,Tom AB - We describe a novel constraint-based approach to approximate ISP link weights using only end-to-end measurements. Common routing protocols such as OSPF and IS-IS choose least-cost paths using link weights, so inferred weights provide a simple, concise, and useful model of intradomain routing. Our approach extends router-level ISP maps, which include only connectivity, with link weights that are consistent with routing. Our inferred weights agree well with observed routing: while our inferred weights fully characterize the set of shortest paths between 84--99% of the router-pairs, alternative models based on hop count and latency do so for only 47--81% of the pairs. JA - Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment T3 - IMW '02 PB - ACM CY - New York, NY, USA SN - 1-58113-603-X UR - http://doi.acm.org/10.1145/637201.637237 M3 - 10.1145/637201.637237 ER - TY - RPRT T1 - Metareasoning for More Effective Human-Computer Dialogue Y1 - 2002 A1 - Perlis, Don A1 - Anderson,Mike KW - *LEARNING MACHINES KW - COMPUTER LOGIC KW - COMPUTER PROGRAMMING AND SOFTWARE KW - CYBERNETICS KW - MAN COMPUTER INTERFACE KW - METAREASONING KW - NATURAL LANGUAGE. KW - PROCESSING AB - The research project explores specific meta-dialogue behaviors in terms of both how a system could be made to perform them, and to what extent they can increase overall system performance. We focus on two types of meta-dialogue capabilities: ability to detect and recover from anomalous dialogue patterns in simple exchanges, and on-line extensions or changes to working vocabulary. Our main method involves detailed representation of the dialogue context, separating domain, language, and dialogue specific aspects, and significant amounts of meta-reasoning about the system's processing of these representations. An existing logical inference system, ALMA/CARNE, developed as part of a pilot study, is being used in an implementation phase of this work. We are also engaged in a study of existing dialogue corpora to investigate the range and frequency of meta-dialogue expressions in different task domains. PB - University of Maryland, College Park UR - http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA414209 ER - TY - CONF T1 - Mixture models for dynamic statistical pressure snakes T2 - 16th International Conference on Pattern Recognition, 2002. Proceedings Y1 - 2002 A1 - Abd-Almageed, Wael A1 - Smith,C.E. KW - active contour models KW - Active contours KW - Artificial intelligence KW - Bayes methods KW - Bayesian methods KW - Bayesian theory KW - complex colored object KW - Computer vision KW - decision making KW - decision making mechanism KW - dynamic statistical pressure snakes KW - Equations KW - expectation maximization algorithm KW - Gaussian distribution KW - image colour analysis KW - Image edge detection KW - Image segmentation KW - Intelligent robots KW - mixture models KW - mixture of Gaussians KW - mixture pressure model KW - Robot vision systems KW - robust pressure model KW - Robustness KW - segmentation results KW - statistical analysis KW - statistical modeling AB - This paper introduces a new approach to statistical pressure snakes. It uses statistical modeling for both object and background to obtain a more robust pressure model. The Expectation Maximization (EM) algorithm is used to model the data into a Mixture of Gaussians (MoG). Bayesian theory is then employed as a decision making mechanism. Experimental results using the traditional pressure model and the new mixture pressure model demonstrate the effectiveness of the new models. JA - 16th International Conference on Pattern Recognition, 2002. Proceedings PB - IEEE VL - 2 SN - 0-7695-1695-X M3 - 10.1109/ICPR.2002.1048404 ER - TY - CONF T1 - Multiple Query Optimization for Data Analysis Applications on Clusters of SMPs T2 - 2nd IEEE/ACM International Symposium on Cluster Computing and the Grid, 2002 Y1 - 2002 A1 - Andrade,H. A1 - Kurc, T. A1 - Sussman, Alan A1 - Saltz, J. KW - Aggregates KW - Application software KW - Bandwidth KW - Data analysis KW - Data structures KW - Delay KW - Query processing KW - scheduling KW - Subcontracting KW - Switched-mode power supply AB - This paper is concerned with the efficient execution of multiple query workloads on a cluster of SMPs. We target applications that access and manipulate large scientific datasets. Queries in these applications involve user-defined processing operations and distributed data structures to hold intermediate and final results. Our goal is to implement system components to leverage previously computed query results and to effectively utilize processing power and aggregated I/O bandwidth on SMP nodes so that both single queries and multi-query batches can be efficiently executed. JA - 2nd IEEE/ACM International Symposium on Cluster Computing and the Grid, 2002 PB - IEEE SN - 0-7695-1582-7 M3 - 10.1109/CCGRID.2002.1017123 ER - TY - CONF T1 - A non-intrusive Kalman filter-based tracker for pursuit eye movement T2 - American Control Conference, 2002. Proceedings of the 2002 Y1 - 2002 A1 - Abd-Almageed, Wael A1 - Fadali,M. S A1 - Bebis,G. KW - Application software KW - characterization KW - Computer vision KW - Current measurement KW - deterministic component KW - Electric variables measurement KW - eye position estimation KW - eye tracking KW - gaze tracking KW - Human computer interaction KW - Kalman filter KW - Kalman filters KW - Lenses KW - Motion estimation KW - Optical reflection KW - pursuit eye movement KW - pursuit motion KW - random component KW - Skin KW - tracking AB - In this paper, we introduce a new non-intrusive approach to estimating the eye position during pursuit motion of the eye. We introduce a new characterization for the pursuit eye movement. Our characterization is based on the decomposition of the pursuit eye motion into a deterministic component and random component. We use a discrete Kalman filter to estimate the random component and calculate the deterministic component. We add the two components to obtain an estimate of the eye position. Simulation results are provided to illustrate the eye position estimation. JA - American Control Conference, 2002. Proceedings of the 2002 PB - IEEE VL - 2 SN - 0-7803-7298-0 UR - http://ieeexplore.ieee.org/ielx5/7965/22015/01023224.pdf?tp=&arnumber=1023224&isnumber=22015 M3 - 10.1109/ACC.2002.1023224 ER - TY - CONF T1 - Persistent caching in a multiple query optimization framework T2 - Proceedings of the 6th Workshop on Languages, Compilers, and Run-Time Systems for Scalable Computers Y1 - 2002 A1 - Andrade,H. A1 - Kurc, T. A1 - Catalyurek,U. A1 - Sussman, Alan A1 - Saltz, J. AB - This paper focuses on persistent caching in multi-client en-vironments, which aims to improve the performance of a data server by caching on disk query results that can be expensive to produce. We present and evaluate extensions to an existing multi-query optimization framework, called MQO, to incorporate persistent caching capabilities. JA - Proceedings of the 6th Workshop on Languages, Compilers, and Run-Time Systems for Scalable Computers ER - TY - CHAP T1 - Polydioptric Cameras: New Eyes for Structure from Motion T2 - Pattern RecognitionPattern Recognition Y1 - 2002 A1 - Neumann, Jan A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Van Gool,Luc AB - We examine the influence of camera design on the estimation of the motion and structure of a scene from video data. Every camera captures a subset of the light rays passing though some volume in space. By relating the differential structure of the time varying space of light rays to different known and new camera designs, we can establish a hierarchy of cameras. This hierarchy is based upon the stability and complexity of the computations necessary to estimate structure and motion. At the low end of this hierarchy is the standard planar pinhole camera for which the structure from motion problem is non-linear and ill-posed. At the high end is a camera, which we call the full field of view polydioptric camera, for which the problem is linear and stable. We develop design suggestions for the polydioptric camera, and based upon this new design we propose a linear algorithm for structure-from-motion estimation, which combines differential motion estimation with differential stereo. JA - Pattern RecognitionPattern Recognition T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2449 SN - 978-3-540-44209-7 UR - http://dx.doi.org/10.1007/3-540-45783-6_74 ER - TY - JOUR T1 - Polydioptric cameras: New eyes for structure from motion JF - Pattern Recognition Y1 - 2002 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. ER - TY - JOUR T1 - A Probabilistic Clustering-Based Indoor Location Determination System JF - Technical Reports from UMIACS, UMIACS-TR-2002-30 Y1 - 2002 A1 - Youssef,Moustafa A A1 - Agrawala, Ashok K. A1 - A. Udaya Shankar A1 - Noh,Sam H KW - Technical Report AB - We present an indoor location determination system based on signalstrength probability distributions for tackling the noisy wireless channel and clustering to reduce computation requirements. We provide two implementation techniques, namely, Joint Clustering and Incremental Triangulation and describe their tradeoffs in terms of location determination accuracy and computation requirement. Both techniques have been incorporated in two implemented context-aware systems: User Positioning System and the Rover System, both running on Compaq iPAQ Pocket PC's with Familiar distribution of Linux for PDA's. The results obtained show that both techniques give the user location with over 90% accuracy to within 7 feet with very low computation requirements, hence enabling a set of context-aware applications. Also UMIACS-TR-2002-30 UR - http://drum.lib.umd.edu/handle/1903/1192 ER - TY - JOUR T1 - Processing large-scale multi-dimensional data in parallel and distributed environments JF - Parallel Computing Y1 - 2002 A1 - Beynon,Michael A1 - Chang,Chialin A1 - Catalyurek,Umit A1 - Kurc,Tahsin A1 - Sussman, Alan A1 - Andrade,Henrique A1 - Ferreira,Renato A1 - Saltz,Joel KW - Data-intensive applications KW - Distributed computing KW - Multi-dimensional datasets KW - PARALLEL PROCESSING KW - Runtime systems AB - Analysis of data is an important step in understanding and solving a scientific problem. Analysis involves extracting the data of interest from all the available raw data in a dataset and processing it into a data product. However, in many areas of science and engineering, a scientist's ability to analyze information is increasingly becoming hindered by dataset sizes. The vast amount of data in scientific datasets makes it a difficult task to efficiently access the data of interest, and manage potentially heterogeneous system resources to process the data. Subsetting and aggregation are common operations executed in a wide range of data-intensive applications. We argue that common runtime and programming support can be developed for applications that query and manipulate large datasets. This paper presents a compendium of frameworks and methods we have developed to support efficient execution of subsetting and aggregation operations in applications that query and manipulate large, multi-dimensional datasets in parallel and distributed computing environments. VL - 28 SN - 0167-8191 UR - http://www.sciencedirect.com/science/article/pii/S0167819102000972 CP - 5 M3 - 10.1016/S0167-8191(02)00097-2 ER - TY - JOUR T1 - Ray interpolants for fast raytracing reflections and refractions JF - Journal of WSCG (Proc. International Conf. in Central Europe on Comp. Graph., Visualization and Comp. Vision) Y1 - 2002 A1 - Atalay,F. B A1 - Mount, Dave AB - To render an object by ray tracing, one or more rays are shot from the viewpoint through every pixel ofthe image plane. For reflective and refractive objects, especially for multiple levels of reflections and/or refractions, this requires many expensive intersection calculations. This paper presents a new method for accelerating ray-tracing of reflective and refractive objects by substituting accurate-but-slow intersection calculations with approximate-but-fast interpolation computations. Our approach is based on modeling the reflective/refractive object as a function that maps input rays entering the object to output rays exiting the object. We are interested in computing the output ray without actually tracing the input ray through the object. This is achieved by adaptively sampling rays from multiple viewpoints in various directions, as a preprocessing phase, and then interpolating the collection of nearby samples to compute an approximate output ray for any input ray. In most cases, object boundaries and other discontinuities are handled by ap- plying various heuristics. In cases where we cannot find sufficient evidence to interpolate, we perform ray tracing as a last resort. We provide performance studies to demonstrate the efficiency of this method. VL - 10 CP - 3 ER - TY - JOUR T1 - Rover: scalable location-aware computing JF - Computer Y1 - 2002 A1 - Banerjee,S. A1 - Agarwal,S. A1 - Kamel,K. A1 - Kochut, A. A1 - Kommareddy,C. A1 - Nadeem,T. A1 - Thakkar,P. A1 - Trinh,Bao A1 - Youssef,A. A1 - Youssef, M. A1 - Larsen,R.L. A1 - Udaya Shankar,A. A1 - Agrawala, Ashok K. KW - amusement KW - application-specific KW - architecture; KW - automation; KW - business KW - business; KW - computing; KW - data KW - entertainment; KW - handheld KW - humanities; KW - integration KW - LAN; KW - location-aware KW - malls; KW - mobile KW - museums; KW - office KW - parks; KW - processing; KW - resource KW - Rover; KW - scalability; KW - scalable KW - scheduling; KW - shopping KW - software KW - system KW - theme KW - units; KW - user; KW - wireless AB - All the components necessary for realizing location-aware computing are available in the marketplace today. What has hindered the widespread deployment of location-based systems is the lack of an integration architecture that scales with user populations. The authors have completed the initial implementation of Rover, a system designed to achieve this sort of integration and to automatically tailor information and services to a mobile user's location. Their studies have validated Rover's underlying software architecture, which achieves system scalability through high-resolution, application-specific resource scheduling at the servers and network. The authors believe that this technology will greatly enhance the user experience in many places, including museums, amusement and theme parks, shopping malls, game fields, offices, and business centers. They designed the system specifically to scale to large user populations and expect its benefits to increase with them. VL - 35 SN - 0018-9162 CP - 10 M3 - 10.1109/MC.2002.1039517 ER - TY - CONF T1 - Scheduling multiple data visualization query workloads on a shared memory machine T2 - Parallel and Distributed Processing Symposium., Proceedings International, IPDPS 2002, Abstracts and CD-ROM Y1 - 2002 A1 - Andrade,H. A1 - Kurc, T. A1 - Sussman, Alan A1 - Saltz, J. KW - Atomic force microscopy KW - Biomedical informatics KW - Computer science KW - Data analysis KW - data visualisation KW - Data visualization KW - datasets KW - deductive databases KW - digitized microscopy image browsing KW - directed graph KW - directed graphs KW - dynamic query scheduling model KW - Educational institutions KW - high workloads KW - image database KW - limited resources KW - multiple data visualization query workloads KW - multiple query optimization KW - performance KW - priority queue KW - Processor scheduling KW - Query processing KW - query ranking KW - Relational databases KW - scheduling KW - shared memory machine KW - shared memory systems KW - Virtual Microscope KW - visual databases AB - Query scheduling plays an important role when systems are faced with limited resources and high workloads. It becomes even more relevant for servers applying multiple query optimization techniques to batches of queries, in which portions of datasets as well as intermediate results are maintained in memory to speed up query evaluation. We present a dynamic query scheduling model based on a priority queue implementation using a directed graph and a strategy for ranking queries. We examine the relative performance of several ranking strategies on a shared-memory machine using two different versions of an application, called the Virtual Microscope, for browsing digitized microscopy images JA - Parallel and Distributed Processing Symposium., Proceedings International, IPDPS 2002, Abstracts and CD-ROM PB - IEEE SN - 0-7695-1573-8 M3 - 10.1109/IPDPS.2002.1015482 ER - TY - CONF T1 - Space-efficient approximate Voronoi diagrams T2 - Proceedings of the thiry-fourth annual ACM symposium on Theory of computing Y1 - 2002 A1 - Arya,Sunil A1 - Malamatos,Theocharis A1 - Mount, Dave AB - (MATH) Given a set $S$ of $n$ points in $\IR^d$, a {\em $(t,\epsilon)$-approximate Voronoi diagram (AVD)} is a partition of space into constant complexity cells, where each cell $c$ is associated with $t$ representative points of $S$, such that for any point in $c$, one of the associated representatives approximates the nearest neighbor to within a factor of $(1+\epsilon)$. Like the Voronoi diagram, this structure defines a spatial subdivision. It also has the desirable properties of being easy to construct and providing a simple and practical data structure for answering approximate nearest neighbor queries. The goal is to minimize the number and complexity of the cells in the AVD.(MATH) We assume that the dimension $d$ is fixed. Given a real parameter $\gamma$, where $2 \le \gamma \le 1/\epsilon$, we show that it is possible to construct a $(t,\epsilon)$-AVD consisting of \[O(n \epsilon^{\frac{d-1}{2}} \gamma^{\frac{3(d-1)}{2}} \log \gamma) \] cells for $t = O(1/(\epsilon \gamma)^{(d-1)/2})$. This yields a data structure of $O(n \gamma^{d-1} \log \gamma)$ space (including the space for representatives) that can answer $\epsilon$-NN queries in time $O(\log(n \gamma) + 1/(\epsilon \gamma)^{(d-1)/2})$. (Hidden constants may depend exponentially on $d$, but do not depend on $\epsilon$ or $\gamma$).(MATH) In the case $\gamma = 1/\epsilon$, we show that the additional $\log \gamma$ factor in space can be avoided, and so we have a data structure that answers $\epsilon$-approximate nearest neighbor queries in time $O(\log (n/\epsilon))$ with space $O(n/\epsilon^{d-1})$, improving upon the best known space bounds for this query time. In the case $\gamma = 2$, we have a data structure that can answer approximate nearest neighbor queries in $O(\log n + 1/\epsilon^{(d-1)/2})$ time using optimal $O(n)$ space. This dramatically improves the previous best space bound for this query time by a factor of $O(1/\epsilon^{(d-1)/2})$.(MATH) We also provide lower bounds on the worst-case number of cells assuming that cells are axis-aligned rectangles of bounded aspect ratio. In the important extreme cases $\gamma \in \{2, 1/\epsilon\}$, our lower bounds match our upper bounds asymptotically. For intermediate values of $\gamma$ we show that our upper bounds are within a factor of $O((1/\epsilon)^{(d-1)/2}\log \gamma)$ of the lower bound. JA - Proceedings of the thiry-fourth annual ACM symposium on Theory of computing T3 - STOC '02 PB - ACM CY - New York, NY, USA SN - 1-58113-495-9 UR - http://doi.acm.org/10.1145/509907.510011 M3 - 10.1145/509907.510011 ER - TY - JOUR T1 - Spatio-temporal stereo using multi-resolution subdivision surfaces JF - International Journal of Computer Vision Y1 - 2002 A1 - Neumann, J. A1 - Aloimonos, J. VL - 47 CP - 1 ER - TY - JOUR T1 - Symbol systems JF - Encyclopedia of Cognitive Science Y1 - 2002 A1 - Anderson,M. L A1 - Perlis, Don ER - TY - CONF T1 - Time-situated agency: Active logic and intention formation T2 - in: Workshop on Cognitive Agents, 25th German Conference on Artificial Intelligence Y1 - 2002 A1 - Anderson,M. L A1 - Josyula,D. P A1 - Okamoto,Y. A A1 - Perlis, Don JA - in: Workshop on Cognitive Agents, 25th German Conference on Artificial Intelligence ER - TY - CONF T1 - Topology inference from BGP routing dynamics T2 - Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment Y1 - 2002 A1 - Andersen,David G. A1 - Feamster, Nick A1 - Bauer,Steve A1 - Balakrishnan,Hari AB - This paper describes a method of inferring logical relationships between network prefixes within an Autonomous System (AS) using only passive monitoring of BGP messages. By clustering these prefixes based upon similarities between their update times, we create a hierarchy linking the prefixes within the larger AS. We can frequently identify groups of prefixes routed to the same ISP Point of Presence (POP), despite the lack of identifying information in the BGP messages. Similarly, we observe disparate prefixes under common organizational control, or with long shared network paths. In addition to discovering interesting network characteristics, our passive method facilitates topology discovery by potentially reducing the number of active probes required in traditional traceroute-based Internet mapping mechanisms. JA - Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment T3 - IMW '02 PB - ACM CY - New York, NY, USA SN - 1-58113-603-X UR - http://doi.acm.org/10.1145/637201.637239 M3 - 10.1145/637201.637239 ER - TY - CONF T1 - The use-mention distinction and its importance to HCI T2 - Proceedings of the Sixth Workshop on the Semantics and Pragmatics of Dialog Y1 - 2002 A1 - Anderson,M. L A1 - Okamoto,Y. A1 - Josyula,D. A1 - Perlis, Don JA - Proceedings of the Sixth Workshop on the Semantics and Pragmatics of Dialog ER - TY - JOUR T1 - Using independent auditors as intrusion detection systems JF - Information and Communications Security Y1 - 2002 A1 - Molina,J. A1 - Arbaugh, William A. ER - TY - JOUR T1 - Visual space-time geometry - A tool for perception and the imagination JF - Proceedings of the IEEE Y1 - 2002 A1 - Fermüller, Cornelia A1 - Baker, P. A1 - Aloimonos, J. KW - 3-D motion estimation KW - Buildings KW - Computer vision KW - Geometry KW - Graphics KW - Image sequences KW - Layout KW - Mathematical model KW - mathematical theory KW - model building KW - Motion estimation KW - multiple view geometry KW - multiple views KW - Navigation KW - optical flow KW - optical illusions KW - patch correspondence KW - Rendering (computer graphics) KW - Robotics and automation KW - Solid modeling KW - structure from motion KW - three-dimensional models KW - visual space-time AB - Although the fundamental ideas underlying research efforts in the field of computer vision have not radically changed in the past two decades, there has been a transformation in the way work in this field is conducted. This is primarily due to the emergence of a number of tools, of both a practical and a theoretical nature. One such tool, celebrated throughout the nineties, is the geometry of visual space-time. It is known under a variety of headings, such as multiple view geometry, structure from motion, and model building. It is a mathematical theory relating multiple views (images) of a scene taken at different viewpoints to three-dimensional models of the (possibly dynamic) scene. This mathematical theory gave rise to algorithms that take as input images (or video) and provide as output a model of the scene. Such algorithms are one of the biggest successes of the field and they have many applications in other disciplines, such as graphics (image-based rendering, motion capture) and robotics (navigation). One of the difficulties, however is that the current tools cannot yet be fully automated, and they do not provide very accurate results. More research is required for automation and high precision. During the past few years we have investigated a number of basic questions underlying the structure from motion problem. Our investigations resulted in a small number of principles that characterize the problem. These principles, which give rise to automatic procedures and point to new avenues for studying the next level of the structure from motion problem, are the subject of this paper. VL - 90 SN - 0018-9219 CP - 7 M3 - 10.1109/JPROC.2002.801440 ER - TY - JOUR T1 - Your 802.11 network has no clothes JF - IEEE Communications Magazine Y1 - 2002 A1 - Mishra,A. A1 - Shin,M. A1 - Arbaugh, William A. VL - 9 ER - TY - JOUR T1 - Animated heads: From 3d motion fields to action descriptions JF - Proceedings of the IFIP TC5/WG5 Y1 - 2001 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. VL - 10 ER - TY - JOUR T1 - Automated design of sheet metal punches for bending multiple parts in a single setup JF - Robotics and Computer-Integrated Manufacturing Y1 - 2001 A1 - Alva,Ujval A1 - Gupta, Satyandra K. KW - Praess planning KW - Punch design KW - Sheet metal bending AB - Sheet metal bending is a process in which bends are formed using a combination of a punch and a die. A very large number of mechanical products such as furniture panels, shelves, cabinets, housing for electro-mechanical devices, etc. are created by using the sheet metal bending process. Bending tools need to satisfy the following two criteria: (1) tools should be able to withstand bending forces, and (2) tool shapes should be such that there is no tool-part interference. In this paper, we describe a methodology for automatically designing shapes of bending punches for bending multiple parts in a single setup. We create parametric geometric models of punches. These parametric models describe the family of possible punch shapes. Using the part geometry and parametric punch shape models, we automatically generated constraints on tool parameters that eliminate the possibility of part-tool interference. We use mixed-integer techniques to identify parameters of punch shapes that result in the maximum punch strength. Finally, we perform strength analysis of the designed punch shape using finite element analysis methods, to verify that the designed punch shape is capable of withstanding the bending forces. VL - 17 SN - 0736-5845 UR - http://www.sciencedirect.com/science/article/pii/S0736584500000351 CP - 1–2 M3 - 10.1016/S0736-5845(00)00035-1 ER - TY - BOOK T1 - Becoming a Scholar in the Digital Age Y1 - 2001 A1 - Duderstadt,James A1 - Arms,William A1 - Messina,Paul A1 - Ellisman,Mark A1 - Atkins,Daniel A1 - Fox,Edward A1 - Shneiderman, Ben A1 - Nissenbaum,Helen A1 - Lederberg,Joshua KW - bibtex-import KW - digital-library KW - dlbook PB - National Research Council ER - TY - CONF T1 - Entropy-preserving cuttings and space-efficient planar point location T2 - Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms Y1 - 2001 A1 - Arya,Sunil A1 - Malamatos,Theocharis A1 - Mount, Dave AB - Point location is the problem of preprocessing a planar polygonal subdivision S into a data structure in order to determine efficiently the cell of the subdivision that contains a given query point. Given the probabilities pz that the query point lies within each cell z ∈ S, a natural question is how to design such a structure so as to minimize the expected-case query time. The entropy H of the probability distribution is the dominant term in the lower bound on the expected-case search time. Clearly the number of edges n of the subdivision is a lower bound on the space required. There is no known approach that simultaneously achieves the goals of H + &Ogr;(H) query time and &Ogr;(n) space. In this paper we introduce entropy-preserving cuttings and show how to use them to achieve query time H + &Ogr;(H), using only &Ogr;(n log* n) space. JA - Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms T3 - SODA '01 PB - Society for Industrial and Applied Mathematics CY - Philadelphia, PA, USA SN - 0-89871-490-7 UR - http://dl.acm.org/citation.cfm?id=365411.365456 ER - TY - CONF T1 - Evolving columnar circuitry for lateral cortical inhibition T2 - Neural Networks, 2001. Proceedings. IJCNN'01. International Joint Conference on Y1 - 2001 A1 - Ayers,D. A1 - Reggia, James A. JA - Neural Networks, 2001. Proceedings. IJCNN'01. International Joint Conference on VL - 1 ER - TY - CHAP T1 - Eyes from Eyes T2 - 3D Structure from Images — SMILE 20003D Structure from Images — SMILE 2000 Y1 - 2001 A1 - Baker,Patrick A1 - Pless,Robert A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Pollefeys,Marc ED - Van Gool,Luc ED - Zisserman,Andrew ED - Fitzgibbon,Andrew AB - We describe a family of new imaging systems, called Argus eyes, that consist of common video cameras arranged in some network. The system we built consists of six cameras arranged so that they sample different parts of the visual sphere. This system has the capability of very accurately estimating its own 3D motion and consequently estimating shape models from the individual videos. The reason is that inherent ambiguities of confusion between translation and rotation disappear in this case. We provide an algorithm and several experiments using real outdoor or indoor images demonstrating the superiority of the new sensor with regard to 3D motion estimation. JA - 3D Structure from Images — SMILE 20003D Structure from Images — SMILE 2000 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2018 SN - 978-3-540-41845-0 UR - http://dx.doi.org/10.1007/3-540-45296-6_14 ER - TY - BOOK T1 - Eyes from Eyes: Analysis of Camera Design Using Plenoptic Video Geometry Y1 - 2001 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - University of Maryland (College Park, Md.). Center for Automation Research AB - We investigate the relationship between camera design and the problem of recovering the motion andstructure of a scene from video data. The visual information that could possibly be obtained is described by the plenoptic function. A camera can be viewed as a device that captures a subset of this function, that is, it measures some of the light rays in some part of the space. The information contained in the subset determines how difficult it is to solve subsequent interpretation processes. By examining the differential structure of the time varying plenoptic function we relate different known and new camera models to the spatio-temporal structure of the observed scene. This allows us to define a hierarchy of camera designs, where the order is determined by the stability and complexity of the computations necessary to estimate structure and motion. At the low end of this hierarchy is the standard planar pinhole camera for which the structure from motion problem is non-linear and ill-posed. At the high end is a camera, which we call the full field of view polydioptric camera, for which the problem is linear and stable. In between are multiple-view cameras with large fields of view which we have built, as well as catadioptric panoramic sensors and other omni-directional cameras. We develop design suggestions for the polydioptric camera, and based upon this new design we propose a linear algorithm for ego- motion estimation, which in essence combines differential motion estimation with differential stereo. PB - Computer Vision Laboratory, Center for Automation Research, University of Maryland ER - TY - CHAP T1 - Geometry of Eye Design: Biology and Technology T2 - Multi-Image Analysis Y1 - 2001 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Klette,Reinhard ED - Gimel’farb,Georgy ED - Huang,Thomas AB - Natural or artificial vision systems process the images that they collect with their eyes or cameras in order to derive information for performing tasks related to navigation and recognition. Since the way images are acquired determines how dificult it is to perform a visual task, and since systems have to cope with limited resources, the eyes used by a specific system should be designed to optimize subsequent image processing as it relates to particular tasks. Different ways of sampling light, i.e., different eyes, may be less or more powerful with respect to particular competences. This seems intuitively evident in view of the variety of eye designs in the biological world. It is shown here that a spherical eye (an eye or system of eyes providing panoramic vision) is superior to a camera-type eye (an eye with restricted field of view) as regards the competence of three-dimensional motion estimation. This result is derived from a statistical analysis of all the possible computational models that can be used for estimating 3D motion from an image sequence. The findings explain biological design in a mathematical manner, by showing that systems that fly and thus need good estimates of 3D motion gain advantages from panoramic vision. Also, insights obtained from this study point to new ways of constructing powerful imaging devices that suit particular tasks in robotics, visualization and virtual reality better than conventional cameras, thus leading to a new camera technology. JA - Multi-Image Analysis T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 2032 SN - 978-3-540-42122-1 UR - http://dx.doi.org/10.1007/3-540-45134-X_2 ER - TY - JOUR T1 - Operating Systems JF - Real-Time Systems Y1 - 2001 A1 - Agrawala, Ashok K. ER - TY - CONF T1 - Personal secure booting T2 - Information Security and Privacy Y1 - 2001 A1 - Itoi,N. A1 - Arbaugh, William A. A1 - Pollack,S. A1 - Reeves,D. JA - Information Security and Privacy ER - TY - JOUR T1 - The price of safety in an active network JF - Journal of Communications and Networks Y1 - 2001 A1 - Alexander,D. S A1 - Menage,P. B A1 - Keromytis,A. D A1 - Arbaugh, William A. A1 - Anagnostakis,K. G A1 - Smith,J. M VL - 3 CP - 1 ER - TY - JOUR T1 - Probabilistic temporal databases JF - ACM Transaction on Database Systems Y1 - 2001 A1 - Alex,D. A1 - Robert,R. A1 - V.S. Subrahmanian VL - 26 CP - 1 ER - TY - RPRT T1 - Revolutionary Advances in Ubiquitious, Real-Time Multicomputers and Runtime Environments Y1 - 2001 A1 - Agrawala, Ashok K. AB - This work was a grant to enhance the Maruti operating system in several ways, in order to provide Mississippi State with a platform upon which their work on the Real-Time Message Passing Interface could be developed. Key technical achievements: (1) Developed predictable Myrinet communications for use in a real-time NOW; (2) Developed the MSU-Kernel to provide a POSIX OS for real- time NOWs; (3) Developed and implemented an algorithm for deploying a globally synchronized clock in a real-time NOW; (4) Developed an improved real-time scheduler for the Maruti hard real-time operating system at University of Maryland (UMD); and (5) Introduced a new parametric approach in Maruti for dynamic scheduling at UMD. Details of the results of the work are presented in papers, thesis and project reports. PB - MISSISSIPPI STATE UNIVERSITY VL - A340293 ER - TY - CONF T1 - A simple entropy-based algorithm for planar point location T2 - Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms Y1 - 2001 A1 - Arya,Sunil A1 - Malamatos,Theocharis A1 - Mount, Dave AB - Given a planar polygonal subdivision S, point location involves preprocessing this subdivision into a data structure so that given any query point q, the cell of the subdivision containing q can be determined efficiently. Suppose that for each cell z in the subdivision, the probability pz that a query point lies within this cell is also given. The goal is to design the data structure to minimize the average search time. It has long been known that the entropy H of the probability distribution is the dominant term in the lower bound on the average-case search time. This problem has been considered before, but existing data structures are all quite complicated. In this paper, we show that a very simple modification of a well-known randomized incremental algorithm can be applied to produce a data structure of expected linear size that can answer point location queries in &Ogr;(H) average time. We also present empirical evidence for the practical efficiency of this approach. JA - Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms T3 - SODA '01 PB - Society for Industrial and Applied Mathematics CY - Philadelphia, PA, USA SN - 0-89871-490-7 UR - http://dl.acm.org/citation.cfm?id=365411.365457 ER - TY - CONF T1 - A spherical eye from multiple cameras (makes better models of the world) T2 - Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2001. CVPR 2001 Y1 - 2001 A1 - Baker, P. A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Pless, R. KW - 3D motion estimation KW - Calibration KW - camera network KW - CAMERAS KW - Computer vision KW - egomotion recovery KW - geometric configuration KW - geometric constraint KW - image gradients KW - image sampling KW - imaging system KW - Laboratories KW - Layout KW - Motion estimation KW - multiple cameras KW - Pixel KW - Robot vision systems KW - SHAPE KW - shape models KW - Space technology KW - spherical eye KW - system calibration KW - video KW - video cameras KW - video signal processing KW - visual sphere sampling AB - The paper describes an imaging system that has been designed specifically for the purpose of recovering egomotion and structure from video. The system consists of six cameras in a network arranged so that they sample different parts of the visual sphere. This geometric configuration has provable advantages compared to small field of view cameras for the estimation of the system's own motion and consequently the estimation of shape models from the individual cameras. The reason is that inherent ambiguities of confusion between translation and rotation disappear. We provide algorithms for the calibration of the system and 3D motion estimation. The calibration is based on a new geometric constraint that relates the images of lines parallel in space to the rotation between the cameras. The 3D motion estimation uses a constraint relating structure directly to image gradients. JA - Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2001. CVPR 2001 PB - IEEE VL - 1 SN - 0-7695-1272-0 M3 - 10.1109/CVPR.2001.990525 ER - TY - CHAP T1 - Statistics Explains Geometrical Optical Illusions T2 - Foundations of Image UnderstandingFoundations of Image Understanding Y1 - 2001 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Davis, Larry S. AB - Azriel Rosenfeld has been our mentor for the last decade. In everyday conversation he stressed the importance of intuition, the unreasonable effectiveness of mathematics in understanding the world, and the power of simplicity inherent in deep ideas. Because we mostly worked on 3D vision, he often argued that 2D vision has been, is, and will continue to be a large source of problems. Strangely enough, we arrived at this study, which is our first on 2D vision, through problems we encountered in our work in 3D motion and shape. Azriel Rosenfeld was also one of the first to apply statistics [ 27 , 28 ] to image analysis and understanding, and he always reminded us of the uncertainties involved in visual computations. This paper shows that statistics cannot be ignored, not even in the interpretation of two simple straight intersecting lines. It demonstrates that uncertainty in the visual data causes problems for the early visual processes. Because of noise, the estimation of features, such as lines, intersections of lines, and local image motion, is biased. The inevitability of this bias provides an explanation for many well-known geometrical optical illusions. JA - Foundations of Image UnderstandingFoundations of Image Understanding T3 - The Kluwer International Series in Engineering and Computer Science PB - Springer US VL - 628 SN - 978-1-4615-1529-6 UR - http://dx.doi.org/10.1007/978-1-4615-1529-6_14 ER - TY - JOUR T1 - The Statistics of Optical Flow JF - Computer Vision and Image Understanding Y1 - 2001 A1 - Fermüller, Cornelia A1 - Shulman,David A1 - Aloimonos, J. AB - When processing image sequences some representation of image motion must be derived as a first stage. The most often used representation is the optical flow field, which is a set of velocity measurements of image patterns. It is well known that it is very difficult to estimate accurate optical flow at locations in an image which correspond to scene discontinuities. What is less well known, however, is that even at the locations corresponding to smooth scene surfaces, the optical flow field often cannot be estimated accurately.Noise in the data causes many optical flow estimation techniques to give biased flow estimates. Very often there is consistent bias: the estimate tends to be an underestimate in length and to be in a direction closer to the majority of the gradients in the patch. This paper studies all three major categories of flow estimation methods—gradient-based, energy-based, and correlation methods, and it analyzes different ways of compounding one-dimensional motion estimates (image gradients, spatiotemporal frequency triplets, local correlation estimates) into two-dimensional velocity estimates, including linear and nonlinear methods. Correcting for the bias would require knowledge of the noise parameters. In many situations, however, these are difficult to estimate accurately, as they change with the dynamic imagery in unpredictable and complex ways. Thus, the bias really is a problem inherent to optical flow estimation. We argue that the bias is also integral to the human visual system. It is the cause of the illusory perception of motion in the Ouchi pattern and also explains various psychophysical studies of the perception of moving plaids. VL - 82 SN - 1077-3142 UR - http://www.sciencedirect.com/science/article/pii/S1077314200909007 CP - 1 M3 - 10.1006/cviu.2000.0900 ER - TY - CONF T1 - Towards the ultimate motion capture technology T2 - Deformable avatars: IFIP TC5/WG5. 10 DEFORM'2000 Workshop, November 29-30, 2000, Geneva, Switzerland and AVATARS'2000 Workshop, November 30-December 1, 2000, Lausanne, Switzerland Y1 - 2001 A1 - Stuart, B. A1 - Baker, P. A1 - Aloimonos, J. JA - Deformable avatars: IFIP TC5/WG5. 10 DEFORM'2000 Workshop, November 29-30, 2000, Geneva, Switzerland and AVATARS'2000 Workshop, November 30-December 1, 2000, Lausanne, Switzerland VL - 68 ER - TY - CONF T1 - A trend analysis of exploitations T2 - 2001 IEEE Symposium on Security and Privacy, 2001. S&P 2001. Proceedings Y1 - 2001 A1 - Browne,H. K A1 - Arbaugh, William A. A1 - McHugh,J. A1 - Fithen,W. L KW - Computer science KW - computer security exploits KW - Data analysis KW - data mining KW - Educational institutions KW - exploitations KW - Performance analysis KW - Predictive models KW - Regression analysis KW - Risk management KW - security of data KW - software engineering KW - system intrusions KW - System software KW - trend analysis KW - vulnerabilities KW - vulnerability exploitation AB - We have conducted an empirical study of a number of computer security exploits and determined that the rates at which incidents involving the exploit are reported to CERT can be modeled using a common mathematical framework. Data associated with three significant exploits involving vulnerabilities in phf, imap, and bind can all be modeled using the formula C=I+S×√M where C is the cumulative count of reported incidents, M is the time since the start of the exploit cycle, and I and S are the regression coefficients determined by analysis of the incident report data. Further analysis of two additional exploits involving vulnerabilities in mountd and statd confirm the model. We believe that the models will aid in predicting the severity of subsequent vulnerability exploitations, based on the rate of early incident reports JA - 2001 IEEE Symposium on Security and Privacy, 2001. S&P 2001. Proceedings PB - IEEE SN - 0-7695-1046-9 M3 - 10.1109/SECPRI.2001.924300 ER - TY - CHAP T1 - Analyzing Action Representations T2 - Algebraic Frames for the Perception-Action CycleAlgebraic Frames for the Perception-Action Cycle Y1 - 2000 A1 - Aloimonos, J. A1 - Fermüller, Cornelia ED - Sommer,Gerald ED - Zeevi,Yehoshua AB - We argue that actions represent the basic seed of intelligence underlying perception of the environment, and the representations encoding actions should be the starting point upon which further studies of cognition are built. In this paper we make a first effort in characterizing these action representations. In particular, from the study of simple actions related to 3D rigid motion interpretation, we deduce a number of principles for the possible computations responsible for the interpretation of space-time geometry. Using these principles, we then discuss possible avenues on how to proceed in analyzing the representations of more complex human actions. JA - Algebraic Frames for the Perception-Action CycleAlgebraic Frames for the Perception-Action Cycle T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1888 SN - 978-3-540-41013-3 UR - http://dx.doi.org/10.1007/10722492_1 ER - TY - JOUR T1 - Approximate range searching JF - Computational Geometry Y1 - 2000 A1 - Arya,Sunil A1 - Mount, Dave KW - Approximation algorithms KW - Box-decomposition trees KW - Partition trees KW - Range searching AB - The range searching problem is a fundamental problem in computational geometry, with numerous important applications. Most research has focused on solving this problem exactly, but lower bounds show that if linear space is assumed, the problem cannot be solved in polylogarithmic time, except for the case of orthogonal ranges. In this paper we show that if one is willing to allow approximate ranges, then it is possible to do much better. In particular, given a bounded range Q of diameter w and ε>0, an approximate range query treats the range as a fuzzy object, meaning that points lying within distance εw of the boundary of Q either may or may not be counted. We show that in any fixed dimension d, a set of n points in Rd can be preprocessed in O(n+logn) time and O(n) space, such that approximate queries can be answered in O(logn(1/ε)d) time. The only assumption we make about ranges is that the intersection of a range and a d-dimensional cube can be answered in constant time (depending on dimension). For convex ranges, we tighten this to O(logn+(1/ε)d−1) time. We also present a lower bound for approximate range searching based on partition trees of Ω(logn+(1/ε)d−1), which implies optimality for convex ranges (assuming fixed dimensions). Finally, we give empirical evidence showing that allowing small relative errors can significantly improve query execution times. VL - 17 SN - 0925-7721 UR - http://www.sciencedirect.com/science/article/pii/S0925772100000225 CP - 3–4 M3 - 10.1016/S0925-7721(00)00022-5 ER - TY - CONF T1 - Automated design of sheet metal bending tools Y1 - 2000 A1 - Alva,U. A1 - Gupta,S.K. A1 - Gupta,R. K. AB - Sheet metal bending is a process in which bends are formed using a combination of apunch and a die. Bending tools need to satisfy the following two criteria: (1) tools should be able to withstand bending forces, and (2) tool shapes should be such that there is no tool-part interference. In this paper, we describe a systematic methodology for automatically synthesizing a punch shape that can be used to produce more than one type of part. We create a parametric geometric model of possible punches. This parametric model describes a family of possible punch shapes. Using the geometric models of various given part types and a parametric punch model, we automatically generate constraints on punch parameters that eliminate the possibility of part-tool interference. We use mixed integer programming techniques to solve these constraints and identify parameters of a punch shape that can work for the given set of parts. Finally, we perform strength analysis of the designed punch to verify that the designed punch is capable of withstanding the bending forces. UR - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.34.5031&rep=rep1&type=pdf ER - TY - CONF T1 - Cortical inhibition as explained by the competitive distribution hypothesis T2 - Network models for control and processing Y1 - 2000 A1 - Reggia, James A. A1 - Sutton III,G. G. A1 - Lynne,C. A1 - D'Autrechy,S. C A1 - Armentrout,S. L JA - Network models for control and processing ER - TY - CONF T1 - Designing StoryRooms: interactive storytelling spaces for children T2 - Proceedings of the 3rd conference on Designing interactive systems: processes, practices, methods, and techniques Y1 - 2000 A1 - Alborzi,H. A1 - Druin, Allison A1 - Montemayor,J. A1 - Platner,M. A1 - Porteous,J. A1 - Sherman,L. A1 - Boltman,A. A1 - Taxén,G. A1 - Best,J. A1 - Hammer,J. A1 - others JA - Proceedings of the 3rd conference on Designing interactive systems: processes, practices, methods, and techniques ER - TY - JOUR T1 - Detecting independent motion: The statistics of temporal continuity JF - Pattern Analysis and Machine Intelligence, IEEE Transactions on Y1 - 2000 A1 - Pless, R. A1 - Brodsky, T. A1 - Aloimonos, J. VL - 22 CP - 8 ER - TY - CONF T1 - A dual interpretation of “standard constraints” in parametric scheduling T2 - Formal Techniques in Real-Time and Fault-Tolerant Systems Y1 - 2000 A1 - Subramani,K. A1 - Agrawala, Ashok K. AB - Parametric scheduling in real-time systems, in the presence of linear relative constraints between the start and execution times of tasks, is a well-studied problem. Prior research established the existence of polynomial time algorithms for the case when the constraints are restricted to be standard and the execution time vectors belong to an axis-parallel hyper-rectangle. In this paper we present a polynomial time algorithm for the case when the execution time vectors belong to arbitrary convex domains. Our insights into the problem occur primarily as a result of studying the dual polytope of the constraint system. JA - Formal Techniques in Real-Time and Fault-Tolerant Systems ER - TY - JOUR T1 - Efficient expected-case algorithms for planar point location JF - Algorithm Theory-SWAT 2000 Y1 - 2000 A1 - Arya,S. A1 - Cheng,S. W A1 - Mount, Dave A1 - Ramesh,H. M3 - 10.1007/3-540-44985-X_31 ER - TY - JOUR T1 - Efficiently computing and updating triangle strips for real-time rendering JF - Computer Aided Design Y1 - 2000 A1 - El-Sana,J. A1 - Evans,F. A1 - Kalaiah,A. A1 - Varshney, Amitabh A1 - Skiena,S. A1 - Azanli,E. AB - Triangle strips are a widely used hardware-supported data-structure to compactly represent and efficiently render polygonal meshes. In thispaper we survey the efficient generation of triangle strips as well as their variants. We present efficient algorithms for partitioning polygonal meshes into triangle strips. Triangle strips have traditionally used a buffer size of two vertices. In this paper we also study the impact of larger buffer sizes and various queuing disciplines on the effectiveness of triangle strips. View-dependent simplification has emerged as a powerful tool for graphics acceleration in visualization of complex environments. However, in a view-dependent framework the triangle mesh connectivity changes at every frame making it difficult to use triangle strips. In this paper we present a novel data-structure, Skip Strip, that efficiently maintains triangle strips during such view-dependent changes. A Skip Strip stores the vertex hierarchy nodes in a skip-list-like manner with path compression. We anticipate that Skip Strips will provide a road-map to combine rendering acceleration techniques for static datasets, typical of retained-mode graphics applications, with those for dynamic datasets found in immediate-mode applications. VL - 32 CP - 13 ER - TY - CONF T1 - A first step towards automated detection of buffer overrun vulnerabilities T2 - The 2000 Network and Distributed Systems Security Conference. San Diego, CA Y1 - 2000 A1 - Wagner,D. A1 - Foster, Jeffrey S. A1 - Brewer,E.A. A1 - Aiken,A. JA - The 2000 Network and Distributed Systems Security Conference. San Diego, CA VL - 14 ER - TY - JOUR T1 - The genome sequence of Drosophila melanogaster JF - Science Y1 - 2000 A1 - Adams,M.D. A1 - Celniker,S.E. A1 - Holt,R.A. A1 - Evans,C.A. A1 - Gocayne,J.D. A1 - Amanatides,P.G. A1 - Scherer,S.E. A1 - Li,P.W. A1 - Hoskins,R.A. A1 - Galle,R.F. A1 - others AB - The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the ∼120-megabase euchromatic portion of theDrosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes ∼13,600 genes, somewhat fewer than the smaller Caenorhabditis elegansgenome, but with comparable functional diversity. VL - 287 SN - 0036-8075, 1095-9203 UR - http://www.sciencemag.org/content/287/5461/2185 CP - 5461 M3 - 10.1126/science.287.5461.2185 ER - TY - JOUR T1 - A model for magnetic aftereffect in the presence of time varying demagnetizing fields JF - Magnetics, IEEE Transactions on Y1 - 2000 A1 - Korman,C.E. A1 - Adly,A.A. A1 - Mayergoyz, Issak D A1 - Rugkwamsook,P. KW - aftereffect; KW - aftereffect;magnetization;numerical KW - demagnetizing KW - field;demagnetisation;magnetic KW - model;magnetic KW - Preisach KW - relaxation;time KW - simulation;thermal KW - varying AB - Preisach models driven by stochastic inputs are employed to model magnetic aftereffect in the presence of demagnetizing fields. As a result of thermal relaxation, the magnetization and, consequently, the demagnetizing field vary in time. The new model generalizes earlier work and self-consistently accounts for the effect of time varying demagnetizing fields on the relaxation process. Three practical numerical techniques are proposed to compute the time variation in the magnetic field and the state of the Preisach plane VL - 36 SN - 0018-9464 CP - 5 M3 - 10.1109/20.908729 ER - TY - CONF T1 - Multi-camera networks: eyes from eyes T2 - IEEE Workshop on Omnidirectional Vision, 2000. Proceedings Y1 - 2000 A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Baker, P. A1 - Pless, R. A1 - Neumann, J. A1 - Stuart, B. KW - Biosensors KW - CAMERAS KW - Computer vision KW - Eyes KW - Image sequences KW - intelligent systems KW - Layout KW - Machine vision KW - Robot vision systems KW - Robustness KW - Spatiotemporal phenomena KW - video cameras KW - Virtual reality AB - Autonomous or semi-autonomous intelligent systems, in order to function appropriately, need to create models of their environment, i.e., models of space time. These are descriptions of objects and scenes and descriptions of changes of space over time, that is, events and actions. Despite the large amount of research on this problem, as a community we are still far from developing robust descriptions of a system's spatiotemporal environment using video input (image sequences). Undoubtedly, some progress has been made regarding the understanding of estimating the structure of visual space, but it has not led to solutions to specific applications. There is, however, an alternative approach which is in line with today's “zeitgeist.” The vision of artificial systems can be enhanced by providing them with new eyes. If conventional video cameras are put together in various configurations, new sensors can be constructed that have much more power and the way they “see” the world makes it much easier to solve problems of vision. This research is motivated by examining the wide variety of eye design in the biological world and obtaining inspiration for an ensemble of computational studies that relate how a system sees to what that system does (i.e. relating perception to action). This, coupled with the geometry of multiple views that has flourished in terms of theoretical results in the past few years, points to new ways of constructing powerful imaging devices which suit particular tasks in robotics, visualization, video processing, virtual reality and various computer vision applications, better than conventional cameras. This paper presents a number of new sensors that we built using common video cameras and shows their superiority with regard to developing models of space and motion JA - IEEE Workshop on Omnidirectional Vision, 2000. Proceedings PB - IEEE SN - 0-7695-0704-2 M3 - 10.1109/OMNVIS.2000.853797 ER - TY - CONF T1 - Nearly optimal expected-case planar point location T2 - Foundations of Computer Science, 2000. Proceedings. 41st Annual Symposium on Y1 - 2000 A1 - Arya,S. A1 - Malamatos,T. A1 - Mount, Dave KW - computational geometry KW - convex cells KW - data structure KW - expected search time KW - nearly optimal expected-case planar point location KW - optimal binary search tree KW - planar point location KW - planar polygonal subdivision KW - polygonal cells KW - polygonal subdivision KW - probability KW - search problems KW - search structure KW - subdivision KW - trees (mathematics) AB - We consider the planar point location problem from the perspective of expected search time. We are given a planar polygonal subdivision S and for each polygon of the subdivision the probability that a query point lies within this polygon. The goal is to compute a search structure to determine which cell of the subdivision contains a given query point, so as to minimize the expected search time. This is a generalization of the classical problem of computing an optimal binary search tree for one-dimensional keys. In the one-dimensional case it has long been known that the entropy H of the distribution is the dominant term in the lower bound on the expected-case search time, and further there exist search trees achieving expected search times of at most H+2. Prior to this work, there has been no known structure for planar point location with an expected search time better than 2H, and this result required strong assumptions on the nature of the query point distribution. Here we present a data structure whose expected search time is nearly equal to the entropy lower bound, namely H+o(H). The result holds for any polygonal subdivision in which the number of sides of each of the polygonal cells is bounded, and there are no assumptions on the query distribution within each cell. We extend these results to subdivisions with convex cells, assuming a uniform query distribution within each cell JA - Foundations of Computer Science, 2000. Proceedings. 41st Annual Symposium on M3 - 10.1109/SFCS.2000.892108 ER - TY - JOUR T1 - New eyes for building models from video JF - Computational Geometry Y1 - 2000 A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Brodský,Tomáš KW - model building KW - shape reconstruction KW - structure from motion KW - video analysis AB - Models of real-world objects and actions for use in graphics, virtual and augmented reality and related fields can only be obtained through the use of visual data and particularly video. This paper examines the question of recovering shape models from video information. Given video of an object or a scene captured by a moving camera, a prerequisite for model building is to recover the three-dimensional (3D) motion of the camera which consists of a rotation and a translation at each instant. It is shown here that a spherical eye (an eye or system of eyes providing panoramic vision) is superior to a camera-type eye (an eye with restricted field of view such as a common video camera) as regards the competence of 3D motion estimation. This result is derived from a geometric/statistical analysis of all the possible computational models that can be used for estimating 3D motion from an image sequence. Regardless of the estimation procedure for a camera-type eye, the parameters of the 3D rigid motion (translation and rotation) contain errors satisfying specific geometric constraints. Thus, translation is always confused with rotation, resulting in inaccurate results. This confusion does not happen for the case of panoramic vision. Insights obtained from this study point to new ways of constructing powerful imaging devices that suit particular tasks in visualization and virtual reality better than conventional cameras, thus leading to a new camera technology. Such new eyes are constructed by putting together multiple existing video cameras in specific ways, thus obtaining eyes from eyes. For a new eye of this kind we describe an implementation for deriving models of scenes from video data, while avoiding the correspondence problem in the video sequence. VL - 15 SN - 0925-7721 UR - http://www.sciencedirect.com/science/article/pii/S0925772199000449 CP - 1–3 M3 - 10.1016/S0925-7721(99)00044-9 ER - TY - CHAP T1 - New Eyes for Shape and Motion Estimation T2 - Biologically Motivated Computer VisionBiologically Motivated Computer Vision Y1 - 2000 A1 - Baker,Patrick A1 - Pless,Robert A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Lee,Seong-Whan ED - Bülthoff,Heinrich ED - Poggio,Tomaso AB - Motivated by the full field of view of insect eyes and their fast and accurate estimation of egomotion, we constructed a system of cameras to take advantage of the full field of view (FOV) constraints that insects use. In this paper, we develop a new ego-motion algorithm for a rigidly mounted set of cameras undergoing arbitrary rigid motion. This egomotion algorithm combines the unambiguous components of the motion computed by each separate camera. We prove that the cyclotorsion is resistant to errors and show this empirically. We show how to calibrate the system with two novel algorithms, one using secondary cameras and one using self calibration. Given this system calibration, the new 3D motion algorithm first computes the rotation and then the 3D translation. We apply this algorithm to a camera system constructed with four rigidly mounted synchronized cameras pointing in various directions and present motion estimation results at www.cfar.umd.edu/ pbaker/argus.html. JA - Biologically Motivated Computer VisionBiologically Motivated Computer Vision T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1811 SN - 978-3-540-67560-0 UR - http://dx.doi.org/10.1007/3-540-45482-9_12 ER - TY - CONF T1 - A New Framework for Multi-camera Structure from Motion T2 - Mustererkennung 2000, 22. DAGM-Symposium Y1 - 2000 A1 - Neumann, J. A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Mustererkennung 2000, 22. DAGM-Symposium ER - TY - JOUR T1 - Observability of 3D Motion JF - International Journal of Computer Vision Y1 - 2000 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - This paper examines the inherent difficulties in observing 3D rigid motion from image sequences. It does so without considering a particular estimator. Instead, it presents a statistical analysis of all the possible computational models which can be used for estimating 3D motion from an image sequence. These computational models are classified according to the mathematical constraints that they employ and the characteristics of the imaging sensor (restricted field of view and full field of view). Regarding the mathematical constraints, there exist two principles relating a sequence of images taken by a moving camera. One is the “epipolar constraint,” applied to motion fields, and the other the “positive depth” constraint, applied to normal flow fields. 3D motion estimation amounts to optimizing these constraints over the image. A statistical modeling of these constraints leads to functions which are studied with regard to their topographic structure, specifically as regards the errors in the 3D motion parameters at the places representing the minima of the functions. For conventional video cameras possessing a restricted field of view, the analysis shows that for algorithms in both classes which estimate all motion parameters simultaneously, the obtained solution has an error such that the projections of the translational and rotational errors on the image plane are perpendicular to each other. Furthermore, the estimated projection of the translation on the image lies on a line through the origin and the projection of the real translation. The situation is different for a camera with a full (360 degree) field of view (achieved by a panoramic sensor or by a system of conventional cameras). In this case, at the locations of the minima of the above two functions, either the translational or the rotational error becomes zero, while in the case of a restricted field of view both errors are non-zero. Although some ambiguities still remain in the full field of view case, the implication is that visual navigation tasks, such as visual servoing, involving 3D motion estimation are easier to solve by employing panoramic vision. Also, the analysis makes it possible to compare properties of algorithms that first estimate the translation and on the basis of the translational result estimate the rotation, algorithms that do the opposite, and algorithms that estimate all motion parameters simultaneously, thus providing a sound framework for the observability of 3D motion. Finally, the introduced framework points to new avenues for studying the stability of image-based servoing schemes. VL - 37 SN - 0920-5691 UR - http://dx.doi.org/10.1023/A:1008177429387 CP - 1 ER - TY - CONF T1 - Optimal design of signaling networks for Internet telephony T2 - IEEE INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings Y1 - 2000 A1 - Srinivasan, Aravind A1 - Ramakrishnan,K. G A1 - Kumaran,K. A1 - Aravamudan,M. A1 - Naqvi,S. KW - bandwidth allocation KW - Computational efficiency KW - Computer networks KW - Cost function KW - Demand forecasting KW - demand forecasts KW - graph theory KW - graphical design tool KW - Internet telephony KW - Linear programming KW - Load forecasting KW - Load management KW - Network topology KW - optimal design KW - optimal load balancing KW - optimisation KW - performance KW - quadratic assignment problem KW - random graphs KW - randomised algorithms KW - randomized heuristics KW - Signal design KW - signaling networks KW - Switches KW - telecommunication signalling KW - topology design AB - We present an approach for efficient design of a signaling network for a network of software switches supporting Internet telephony. While one may take an integer programming approach to solve this problem, it quickly becomes intractable even for modest-sized networks. Instead, our topology design uses random graphs that we show to be nearly optimal in cost, highly connected, and computationally efficient even for large networks. We then formulate a quadratic assignment problem (QAP) to map the abstract topology into the physical network to achieve optimal load balancing for given demand forecasts, which we solve using randomized heuristics. Numerical results on several example networks illustrate the performance and computational efficiency of our method. A graphical design tool has been developed based on our algorithms JA - IEEE INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings PB - IEEE VL - 2 SN - 0-7803-5880-5 M3 - 10.1109/INFCOM.2000.832245 ER - TY - JOUR T1 - The Ouchi illusion as an artifact of biased flow estimation JF - Vision Research Y1 - 2000 A1 - Fermüller, Cornelia A1 - Pless,Robert A1 - Aloimonos, J. KW - Bias KW - MOTION KW - optical flow KW - Plaid KW - Statistics AB - A pattern by Ouchi has the surprising property that small motions can cause illusory relative motion between the inset and background regions. The effect can be attained with small retinal motions or a slight jiggling of the paper and is robust over large changes in the patterns, frequencies and boundary shapes. In this paper, we explain that the cause of the illusion lies in the statistical difficulty of integrating local one-dimensional motion signals into two-dimensional image velocity measurements. The estimation of image velocity generally is biased, and for the particular spatial gradient distributions of the Ouchi pattern the bias is highly pronounced, giving rise to a large difference in the velocity estimates in the two regions. The computational model introduced to describe the statistical estimation of image velocity also accounts for the findings of psychophysical studies with variations of the Ouchi pattern and for various findings on the perception of moving plaids. The insight gained from this computational study challenges the current models used to explain biological vision systems and to construct robotic vision systems. Considering the statistical difficulties in image velocity estimation in conjunction with the problem of discontinuity detection in motion fields suggests that theoretically the process of optical flow computations should not be carried out in isolation but in conjunction with the higher level processes of 3D motion estimation, segmentation and shape computation. VL - 40 SN - 0042-6989 UR - http://www.sciencedirect.com/science/article/pii/S0042698999001625 CP - 1 M3 - 10.1016/S0042-6989(99)00162-5 ER - TY - CONF T1 - Polymorphic versus monomorphic points-to analysis T2 - Proceedings of the 7th International Static Analysis Symposium, Lecture Notes in Computer Science. Springer Verlag Y1 - 2000 A1 - Foster, Jeffrey S. A1 - Fahndrich,M. A1 - Aiken,A. JA - Proceedings of the 7th International Static Analysis Symposium, Lecture Notes in Computer Science. Springer Verlag ER - TY - CONF T1 - Receiver based management of low bandwidth access links T2 - IEEE INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings Y1 - 2000 A1 - Spring, Neil A1 - Chesire,M. A1 - Berryman,M. A1 - Sahasranaman,V. A1 - Anderson,T. A1 - Bershad,B. KW - Bandwidth KW - buffer storage KW - bulk-transfer applications KW - complex Web page KW - congestion control policy KW - Delay KW - dynamically loadable Linux kernel module KW - information resources KW - interactive network KW - Internet KW - Kernel KW - link utilization KW - Linux KW - low-bandwidth access links KW - mixed traffic load KW - packet latency KW - queue length KW - queueing theory KW - receive socket buffer sizes KW - receiver-based management KW - response time KW - short flow prioritizing KW - Size control KW - Sockets KW - subscriber loops KW - TCP flow control KW - telecommunication congestion control KW - telecommunication network management KW - Telecommunication traffic KW - Testing KW - Throughput KW - Transport protocols KW - Unix KW - Web pages AB - In this paper, we describe a receiver-based congestion control policy that leverages TCP flow control mechanisms to prioritize mixed traffic loads across access links. We manage queueing at the access link to: (1) improve the response time of interactive network applications; (2) reduce congestion-related packet losses; while (3) maintaining high throughput for bulk-transfer applications. Our policy controls queue length by manipulating receive socket buffer sizes. We have implemented this solution in a dynamically loadable Linux kernel module, and tested it over low-bandwidth links. Our approach yields a 7-fold improvement in packet latency over an unmodified system while maintaining 94% link utilization. In the common case, congestion-related packet losses at the access link can be eliminated. Finally, by prioritizing short flows, we show that our system reduces the time to download a complex Web page during a large background transfer by a factor of two JA - IEEE INFOCOM 2000. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings PB - IEEE VL - 1 SN - 0-7803-5880-5 M3 - 10.1109/INFCOM.2000.832194 ER - TY - JOUR T1 - A Review of Current Routing Protocols for Ad Hoc JF - IEEE Personal Communications Y1 - 2000 A1 - Royer,E.M. A1 - Toh,C.K. A1 - Hicks, Michael W. A1 - Kakkar,P. A1 - Moore,J. T A1 - Hicks, Michael W. A1 - Moore,J. T A1 - Alexander,D. S A1 - Gunter,C. A A1 - Nettles,S. A1 - others VL - 29 ER - TY - CHAP T1 - Scalable Resource Control in Active Networks T2 - Active NetworksActive Networks Y1 - 2000 A1 - Anagnostakis,Kostas A1 - Hicks, Michael W. A1 - Ioannidis,Sotiris A1 - Keromytis,Angelos A1 - Smith,Jonathan ED - Yasuda,Hiroshi AB - The increased complexity of the service model relative to store-and-forward routers has made resource management one of the paramount concerns in active networking research and engineering. In this paper,we address two major challenges in scaling resource management-to-many-node active networks. The first is the use of market mechanisms and trading amongst nodes and programs with varying degrees of competition and cooperation to provide a scalable approach to managing active network resources. The second is the use of a trust-management architecture to ensure that the participants in the resource management marketplace have a policy-driven “rule of law” in which marketplace decisions can be made and relied upon. We have used lottery scheduling and the Keynote trust-management system for our implementation, for which we provide some initial performance indications. JA - Active NetworksActive Networks T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1942 SN - 978-3-540-41179-6 UR - http://dx.doi.org/10.1007/3-540-40057-5_25 ER - TY - JOUR T1 - Secure quality of service handling: SQoSH JF - IEEE Communications Magazine Y1 - 2000 A1 - Alexander,D. S A1 - Arbaugh, William A. A1 - Keromytis,A. D A1 - Muir,S. A1 - Smith,J. M KW - Acceleration KW - Access control KW - active networks KW - ALIEN active loader KW - Clocks KW - Computer network management KW - cryptographic credentials KW - cryptography KW - customized networking services KW - Data security KW - Data structures KW - denial-of-service attacks KW - interfaces KW - Kernel KW - loaded modules KW - network resources KW - network traffic KW - open signaling KW - packet switching KW - Piglet lightweight device kernel KW - programmable network element KW - programmable network infrastructures KW - Programming profession KW - Proposals KW - quality of service KW - remote invocation KW - resource control KW - restricted control of quality of service KW - SANE KW - scheduling KW - scheduling discipline KW - secure active network environment architecture KW - secure quality of service handling KW - security infrastructure KW - security risks KW - SQoSH KW - SwitchWare architecture KW - telecommunication security KW - tuning knobs KW - virtual clock AB - Proposals for programmable network infrastructures, such as active networks and open signaling, provide programmers with access to network resources and data structures. The motivation for providing these interfaces is accelerated introduction of new services, but exposure of the interfaces introduces many new security risks. We describe some of the security issues raised by active networks. We then describe our secure active network environment (SANE) architecture. SANE was designed as a security infrastructure for active networks, and was implemented in the SwitchWare architecture. SANE restricts the actions that loaded modules can perform by restricting the resources that can be named; this is further extended to remote invocation by means of cryptographic credentials. SANE can be extended to support restricted control of quality of service in a programmable network element. The Piglet lightweight device kernel provides a “virtual clock” type of scheduling discipline for network traffic, and exports several tuning knobs with which the clock can be adjusted. The ALIEN active loader provides safe access to these knobs to modules that operate on the network element. Thus, the proposed SQoSH architecture is able to provide safe, secure access to network resources, while allowing these resources to be managed by end users needing customized networking services. A desirable consequence of SQoSH's integration of access control and resource control is that a large class of denial-of-service attacks, unaddressed solely with access control and cryptographic protocols, can now be prevented VL - 38 SN - 0163-6804 CP - 4 M3 - 10.1109/35.833566 ER - TY - CONF T1 - The statistics of optical flow: implications for the process of correspondence in vision T2 - 15th International Conference on Pattern Recognition, 2000. Proceedings Y1 - 2000 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - Bias KW - Computer vision KW - correlation KW - correlation methods KW - energy-based method KW - flow estimation KW - Frequency estimation KW - gradient method KW - gradient methods KW - Image analysis KW - Image motion analysis KW - Image sequences KW - least squares KW - least squares approximations KW - Motion estimation KW - Nonlinear optics KW - Optical feedback KW - optical flow KW - Optical harmonic generation KW - Optical noise KW - Statistics KW - Visual perception AB - This paper studies the three major categories of flow estimation methods: gradient-based, energy-based, and correlation methods; it analyzes different ways of compounding 1D motion estimates (image gradients, spatio-temporal frequency triplets, local correlation estimates) into 2D velocity estimates, including linear and nonlinear methods. Correcting for the bias would require knowledge of the noise parameters. In many situations, however, these are difficult to estimate accurately, as they change with the dynamic imagery in unpredictable and complex ways. Thus, the bias really is a problem inherent to optical flow estimation. We argue that the bias is also integral to the human visual system. It is the cause of the illusory perception of motion in the Ouchi pattern and also explains various psychophysical studies of the perception of moving plaids. Finally, the implication of the analysis is that flow or correspondence can be estimated very accurately only when feedback is utilized JA - 15th International Conference on Pattern Recognition, 2000. Proceedings PB - IEEE VL - 1 SN - 0-7695-0750-6 M3 - 10.1109/ICPR.2000.905288 ER - TY - JOUR T1 - Structure from motion: Beyond the epipolar constraint JF - International Journal of Computer Vision Y1 - 2000 A1 - Brodskỳ, T. A1 - Fermüller, Cornelia A1 - Aloimonos, J. VL - 37 CP - 3 ER - TY - MGZN T1 - Windows of Vulnerability: A Case Study Analysis Y1 - 2000 A1 - Arbaugh, William A. A1 - Fithen,William L. A1 - McHugh,John AB - The authors propose a life-cycle model for system vulnerabilities, applying to three case studies to show how systems remain vulnerable long after security fixes are available. Complex information and communication systems give rise to design, implementation, and management errors, leading to a vulnerability in an information technology product that can allow security policy violations. Using their vulnerability life-cycle model, the authors present a case study analysis of specific computer vulnerabilities. For each case, the authors provide background information about the vulnerability, such as how attackers exploited it and which systems were affected. They tie the case to the life-cycle model by identifying the dates for each state within the model. Finally, they use a histogram of reported intrusions to show the life of the vulnerability and conclude with an analysis specific to the particular vulnerability. JA - Computer VL - 33 SN - 0018-9162 CP - 12 ER - TY - CHAP T1 - Active Perception T2 - Wiley Encyclopedia of Electrical and Electronics EngineeringWiley Encyclopedia of Electrical and Electronics Engineering Y1 - 1999 A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Wiley Encyclopedia of Electrical and Electronics EngineeringWiley Encyclopedia of Electrical and Electronics Engineering PB - John Wiley & Sons, Inc. SN - 9780471346081 UR - http://onlinelibrary.wiley.com/doi/10.1002/047134608X.W5515/abstract?systemMessage=Wiley+Online+Library+will+be+disrupted+17+March+from+10-14+GMT+%2806-10+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage= ER - TY - CONF T1 - Advances in spherical harmonic device modeling: calibration and nanoscale electron dynamics T2 - Simulation of Semiconductor Processes and Devices, 1999. SISPAD '99. 1999 International Conference on Y1 - 1999 A1 - Lin,Chung-Kai A1 - Goldsman,N. A1 - Mayergoyz, Issak D A1 - Aronowitz,S. A1 - Belova,N. KW - Boltzmann KW - characteristics;SHBTE KW - current;surface KW - device KW - dynamics;spherical KW - electron KW - equation;calibration;semiconductor KW - equation;I-V KW - harmonic KW - model;substrate KW - models;surface KW - scattering; KW - scattering;Boltzmann KW - simulation;calibration;nanoscale KW - transport AB - Improvements in the Spherical Harmonic (SH) method for solving Boltzmann Transport Equation (BTE) are presented. The simulation results provide the same physical detail as analytical band Monte Carlo (MC) calculations, and are obtained approximately a thousand times faster. A new physical model for surface scattering has also been developed. As a result, the SHBTE model achieves calibration for a complete process of I-V characteristics and substrate current consistently for the first time JA - Simulation of Semiconductor Processes and Devices, 1999. SISPAD '99. 1999 International Conference on M3 - 10.1109/SISPAD.1999.799287 ER - TY - CONF T1 - Automated punch shape synthesis for sheet metal bending operations Y1 - 1999 A1 - Alva,U. A1 - Gupta,S.K. ER - TY - JOUR T1 - Binary version management for computational grids JF - Parallel processing letters Y1 - 1999 A1 - Hollingsworth, Jeffrey K A1 - Miller, E. L A1 - Akala, K. VL - 9 CP - 2 ER - TY - JOUR T1 - Coverage estimation methods for stratified fault-injection JF - Computers, IEEE Transactions on Y1 - 1999 A1 - Cukier, Michel A1 - Powell,D. A1 - Ariat,J. KW - Bayes methods KW - Bayesian estimations KW - confidence regions KW - coverage estimation methods KW - fault tolerance coverage KW - fault tolerant computing KW - frequentist confidence limits KW - parameter estimation KW - parameters estimation KW - Pearson distribution system KW - statistical processing KW - stratified fault-injection KW - stratified sampling KW - vectorial statistic AB - This paper addresses the problem of estimating fault tolerance coverage through statistical processing of observations collected in fault-injection experiments. In an earlier paper, venous estimators based on simple sampling in the complete fault/activity input space and stratified sampling in a partitioned space were studied; frequentist confidence limits were derived based on a normal approximation. In this paper, the validity of this approximation is analyzed. The theory of confidence regions is introduced to estimate coverage without approximation when stratification is used. Three statistics are considered for defining confidence regions. It is shown that one-a vectorial statistic-is often more conservative than the other two. However, only the vectorial statistic is computationally tractable. We then consider Bayesian estimation methods for stratified sampling. Two methods are presented to obtain an approximation of the posterior distribution of the coverage by calculating its moments. The moments are then used to identify the type of the distribution in the Pearson distribution system, to estimate its parameters, and to obtain the coverage confidence limit. Three hypothetical example systems are used to compare the validity and the conservatism of the frequentist and Bayesian estimations VL - 48 SN - 0018-9340 CP - 7 M3 - 10.1109/12.780878 ER - TY - CONF T1 - Field-to-frame transcoding with spatial and temporal downsampling T2 - Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on Y1 - 1999 A1 - Wee,S.J. A1 - Apostolopoulos,J.G. A1 - Feamster, Nick KW - data compression KW - decoding KW - Encoding KW - field-coded interlaced video KW - field-to-frame transcoding KW - frame-coded progressive video KW - H.263 motion estimation KW - H.263 transcoding KW - high-rate compressed bitstreams KW - lower-rate compressed bitstreams KW - Motion estimation KW - MPEG-1 KW - MPEG-2 KW - MPEG-4 KW - spatial downsampling KW - standards KW - temporal downsampling KW - transcoder KW - video coding KW - video compression standards AB - We present an algorithm for transcoding high-rate compressed bitstreams containing field-coded interlaced video to lower-rate compressed bitstreams containing frame-coded progressive video. We focus on MPEG-2 to H.263 transcoding, however these results can be extended to other lower-rate video compression standards including MPEG-4 simple profile and MPEG-1. A conventional approach to the transcoding problem involves decoding the input bitstream, spatially and temporally downsampling the decoded frames, and re-encoding the result. The proposed transcoder achieves improved performance by exploiting the details of the MPEG-2 and H.263 compression standards when performing interlaced to progressive (or field to frame) conversion with spatial downsampling and frame-rate reduction. The transcoder reduces the MPEG-2 decoding requirements by temporally downsampling the data at the bitstream level and reduces the H.263 encoding requirements by largely bypassing H.263 motion estimation by reusing the motion vectors and coding modes given in the input bitstream. In software implementations, the proposed approach achieved a 5 times; speedup over the conventional approach with only a 0.3 and 0.5 dB loss in PSNR for the Carousel and Bus sequences JA - Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on VL - 4 M3 - 10.1109/ICIP.1999.819593 ER - TY - CONF T1 - Fkpurang, darsana, traum, cfa, perlisg@ cs. umd. edu T2 - In Proceedings of the IJCAI’99 Workshop on Practical Reasoning and Rationality Y1 - 1999 A1 - Edu,C. U A1 - Purang,K. A1 - Purushothaman,D. A1 - Traum,D. A1 - Andersen,C. A1 - Perlis, Don JA - In Proceedings of the IJCAI’99 Workshop on Practical Reasoning and Rationality ER - TY - CONF T1 - Independent motion: the importance of history T2 - Computer Vision and Pattern Recognition, 1999. IEEE Computer Society Conference on. Y1 - 1999 A1 - Pless, R. A1 - Brodsky, T. A1 - Aloimonos, J. KW - aerial visual surveillance KW - background image KW - Fluid flow measurement KW - Frequency measurement KW - History KW - Motion detection KW - Motion estimation KW - Motion measurement KW - Noise measurement KW - Optical computing KW - Optical noise KW - spatiotemporal image intensity gradient measurements KW - Spatiotemporal phenomena KW - Surveillance KW - Video sequences AB - We consider a problem central in aerial visual surveillance applications-detection and tracking of small, independently moving objects in long and noisy video sequences. We directly use spatiotemporal image intensity gradient measurements to compute an exact model of background motion. This allows the creation of accurate mosaics over many frames and the definition of a constraint violation function which acts as an indication of independent motion. A novel temporal integration method maintains confidence measures over long subsequences without computing the optic flow, requiring object models, or using a Kalman filler. The mosaic acts as a stable feature frame, allowing precise localization of the independently moving objects. We present a statistical analysis of the effects of image noise on the constraint violation measure and find a good match between the predicted probability distribution function and the measured sample frequencies in a test sequence JA - Computer Vision and Pattern Recognition, 1999. IEEE Computer Society Conference on. PB - IEEE VL - 2 SN - 0-7695-0149-4 M3 - 10.1109/CVPR.1999.784614 ER - TY - CONF T1 - Mixed initiative dialogue and intelligence via active logic T2 - proceedings of the AAAI99 Workshop on Mixed-Initiative Intelligence Y1 - 1999 A1 - Andersen,C. A1 - Traum,D. A1 - Purang,K. A1 - Purushothaman,D. A1 - Perlis, Don JA - proceedings of the AAAI99 Workshop on Mixed-Initiative Intelligence ER - TY - CONF T1 - Motion Segmentation: A Synergistic Approach T2 - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on Y1 - 1999 A1 - Fermüller, Cornelia A1 - Brodsky, Tomas A1 - Aloimonos, J. KW - epipolar minimization KW - independent motion detection KW - Motion analysis AB - Since estimation of camera motion requires knowledge of independent motion, and moving object detection and localization requires knowledge about the camera motion, the two problems of motion estimation and segmentation need to be solved together in a synergistic manner. This paper provides an approach to treating both these problems simultaneously. The technique introduced here is based on a novel concept, ``scene ruggedness,'' which parameterizes the variation in estimated scene depth with the error in the underlying three-dimensional (3D) motion. The idea is that incorrect 3D motion estimates cause distortions in the estimated depth map, and as a result smooth scene patches are computed as rugged surfaces. The correct 3D motion can be distinguished, as it does not cause any distortion and thus gives rise to the background patches with the least depth variation between depth discontinuities, with the locations corresponding to independent motion being rugged. The algorithm presented employs a binocular observer whose nature is exploited in the extraction of depth discontinuities, a step that facilitates the overall procedure, but the technique can be extended to a monocular observer in a variety of ways. JA - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on PB - IEEE Computer Society CY - Los Alamitos, CA, USA VL - 2 M3 - http://doi.ieeecomputersociety.org/10.1109/CVPR.1999.784633 ER - TY - CONF T1 - PLANet: an active internetwork T2 - IEEE INFOCOM '99. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings Y1 - 1999 A1 - Hicks, Michael W. A1 - Moore,J. T A1 - Alexander,D. S A1 - Gunter,C. A A1 - Nettles,S. M KW - 100 Mbit/s KW - 300 MHz KW - 48 Mbit/s KW - active internetwork KW - active network architecture KW - active network implementation KW - byte-code-interpreted applications KW - Computer architecture KW - Computer languages KW - Computer networks KW - congested conditions KW - dynamic programming KW - dynamic router extensions KW - Ethernet KW - Ethernet networks KW - INFORMATION SCIENCE KW - Internet KW - Internet-like services KW - internetworking KW - IP KW - IP networks KW - link layers KW - Linux user-space applications KW - Local area networks KW - ML dialect KW - Network performance KW - networking operations KW - OCaml KW - Packet Language for Active Networks KW - packet programs KW - packet switching KW - Pentium-II KW - performance KW - performance evaluation KW - PLAN KW - PLANet KW - Planets KW - programmability features KW - programming languages KW - router functionality KW - special purpose programming language KW - Switches KW - telecommunication network routing KW - Transport protocols KW - Web and internet services AB - We present PLANet: an active network architecture and implementation. In addition to a standard suite of Internet-like services, PLANet has two key programmability features: (1) all packets contain programs; and (2) router functionality may be extended dynamically. Packet programs are written in our special purpose programming language PLAN, the Packet Language for Active Networks, while dynamic router extensions are written in OCaml, a dialect of ML. Currently, PLANet routers run as byte-code-interpreted Linux user-space applications, and support Ethernet and IP as link layers. PLANet achieves respectable performance on standard networking operations: on 300 MHz Pentium-II's attached to 100 Mbps Ethernet, PLANet can route 48 Mbps and switch over 5000 packets per second. We demonstrate the utility of PLANet's activeness by showing experimentally how it can nontrivially improve application and aggregate network performance in congested conditions JA - IEEE INFOCOM '99. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings PB - IEEE VL - 3 SN - 0-7803-5417-6 M3 - 10.1109/INFCOM.1999.751668 ER - TY - CONF T1 - Practical reasoning and plan execution with active logic T2 - Proceedings of the IJCAI-99 Workshop on Practical Reasoning and Rationality Y1 - 1999 A1 - Purang,K. A1 - Purushothaman,D. A1 - Traum,D. A1 - Andersen,C. A1 - Perlis, Don JA - Proceedings of the IJCAI-99 Workshop on Practical Reasoning and Rationality ER - TY - JOUR T1 - Reports on the AAAI Fall Symposia JF - AI Magazine Y1 - 1999 A1 - De Giacomo,Giuseppe A1 - desJardins, Marie A1 - Canamero,Dolores A1 - Wasson,Glenn A1 - Littman,Michael A1 - Allwein,Gerard A1 - Marriott,Kim A1 - Meyer,Bernd A1 - Webb,Barbara A1 - Consi,Tom AB - The Association for the Advancement of Artificial Intelligence (AAAI) held its 1998 Fall Symposium Series on 23 to 25 October at the Omni Rosen Hotel in Orlando, Florida. This article contains summaries of seven of the symposia that were conducted: (1) Cognitive Robotics; (2) Distributed, Continual Planning; (3) Emotional and Intelligent: The Tangled Knot of Cognition; (4) Integrated Planning for Autonomous Agent Architectures; (5) Planning with Partially Observable Markov Decision Processes; (6) Reasoning with Visual and Diagrammatic Representations; and (7) Robotics and Biology: Developing Connections. VL - 20 SN - 0738-4602 UR - http://www.aaai.org/ojs/index.php/aimagazine/article/viewArticle/1470 CP - 3 M3 - 10.1609/aimag.v20i3.1470 ER - TY - BOOK T1 - The RNA World Y1 - 1999 A1 - Woodson,Sarah A. A1 - Mount, Stephen M. ED - Gesteland,Raymond F. ED - Cech,Thomas R. ED - Atkins,John F. PB - Cold Spring Harbor Laboratory Press CY - Cold Spring Harbor, New York ER - TY - JOUR T1 - The Role of Children in the Design of New Technology JF - Saatavilla www-muodossa: ftp://ftp. cs. umd. edu/pub/hcil/Reports-Abstracts-Bibliography/99-23html/99-23. pdf (Luettu 17.1. 2007) Y1 - 1999 A1 - Allison,D. ER - TY - CONF T1 - Shape from Video T2 - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on Y1 - 1999 A1 - Brodsky, Tomas A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - epipolar minimization KW - model extraction KW - Motion analysis KW - vision and graphics AB - This paper presents a novel technique for recovering the shape of a static scene from a video sequence due to a rigidly moving camera. The solution procedure consists of two stages. In the first stage, the rigid motion of the camera at each instant in time is recovered. This provides the transformation between successive viewing positions. The solution is achieved through new constraints which relate 3D motion and shape directly to the image derivatives. These constraints allow the combination of the processes of 3D motion estimation and segmentation by exploiting the geometry and statistics inherent in the data. In the second stage the scene surfaces are reconstructed through an optimization procedure which utilizes data from all the frames of a short video sequence. A number of experimental results demonstrate the potential of the approach. JA - Computer Vision and Pattern Recognition, IEEE Computer Society Conference on PB - IEEE Computer Society CY - Los Alamitos, CA, USA VL - 2 M3 - http://doi.ieeecomputersociety.org/10.1109/CVPR.1999.784622 ER - TY - CONF T1 - Skip Strips: maintaining triangle strips for view-dependent rendering T2 - Visualization '99. Proceedings Y1 - 1999 A1 - El-Sana,J. A1 - Azanli,E. A1 - Varshney, Amitabh KW - (computer KW - Acceleration KW - acceleration;graphics KW - applications;path KW - applications;skip-list-like KW - changes;view-dependent KW - compression;rendering KW - connectivity;triangle KW - data KW - datasets;graphics KW - datasets;static KW - environments;data KW - equipment;data KW - graphic KW - Graphics KW - graphics);spatial KW - hardware;hardware-supported KW - hierarchy KW - manner;static KW - mechanism;immediate-mode KW - mesh KW - meshes;triangle KW - nodes;view-dependent KW - rendering;view-dependent KW - simplification;visualization;computer KW - Skip KW - Strips;complex KW - strips;vertex KW - structure;dynamic KW - structures; KW - techniques;retained-mode KW - triangle KW - visualisation;rendering AB - View-dependent simplification has emerged as a powerful tool for graphics acceleration in visualization of complex environments. However, view-dependent simplification techniques have not been able to take full advantage of the underlying graphics hardware. Specifically, triangle strips are a widely used hardware-supported mechanism to compactly represent and efficiently render static triangle meshes. However, in a view-dependent framework, the triangle mesh connectivity changes at every frame, making it difficult to use triangle strips. We present a novel data structure, Skip Strip, that efficiently maintains triangle strips during such view-dependent changes. A Skip Strip stores the vertex hierarchy nodes in a skip-list-like manner with path compression. We anticipate that Skip Strips will provide a road map to combine rendering acceleration techniques for static datasets, typical of retained-mode graphics applications, with those for dynamic datasets found in immediate-mode applications. JA - Visualization '99. Proceedings M3 - 10.1109/VISUAL.1999.809877 ER - TY - CONF T1 - Statistical biases in optic flow T2 - Computer Vision and Pattern Recognition, 1999. IEEE Computer Society Conference on. Y1 - 1999 A1 - Fermüller, Cornelia A1 - Pless, R. A1 - Aloimonos, J. KW - Distributed computing KW - Frequency domain analysis KW - HUMANS KW - image derivatives KW - Image motion analysis KW - Image sequences KW - Least squares methods KW - Motion estimation KW - Optical computing KW - Optical distortion KW - optical flow KW - Optical noise KW - Ouchi illusion KW - perception of motion KW - Psychology KW - Spatiotemporal phenomena KW - statistical analysis KW - systematic bias KW - total least squares AB - The computation of optical flow from image derivatives is biased in regions of non uniform gradient distributions. A least-squares or total least squares approach to computing optic flow from image derivatives even in regions of consistent flow can lead to a systematic bias dependent upon the direction of the optic flow, the distribution of the gradient directions, and the distribution of the image noise. The bias a consistent underestimation of length and a directional error. Similar results hold for various methods of computing optical flow in the spatiotemporal frequency domain. The predicted bias in the optical flow is consistent with psychophysical evidence of human judgment of the velocity of moving plaids, and provides an explanation of the Ouchi illusion. Correction of the bias requires accurate estimates of the noise distribution; the failure of the human visual system to make these corrections illustrates both the difficulty of the task and the feasibility of using this distorted optic flow or undistorted normal flow in tasks requiring higher lever processing JA - Computer Vision and Pattern Recognition, 1999. IEEE Computer Society Conference on. PB - IEEE VL - 1 SN - 0-7695-0149-4 M3 - 10.1109/CVPR.1999.786994 ER - TY - JOUR T1 - Temporal visualization for legal case histories JF - PROCEEDINGS OF THE ANNUAL MEETING-AMERICAN SOCIETY FOR INFORMATION SCIENCE Y1 - 1999 A1 - Harris,C. A1 - Allen,R.B. A1 - Plaisant, Catherine A1 - Shneiderman, Ben AB - This paper discusses visualization of legal information using a tool for temporal information called LifeLines. The direct and indirect histories of cases can become very complex. We explored ways that LifeLines could aid in viewing the links between the original case and the direct and indirect histories. The Apple Computer, Inc. v. Microsoft Corporation and Hewlett Packard Company case is used to illustrate the prototype. For example, if users want to find out how the rulings or statutes changed throughout this case, they could retrieve this information within a single display. Using the timeline, users could also choose at which point in time they would like to begin viewing the case. LifeLines support various views of a case's history. For instance, users can view the trial history of a case, the references involved in a case, and citations made to a case. The paper describes improvements to LifeLines that could help in providing a more useful visualization of case history. VL - 36 ER - TY - CONF T1 - A theory of type qualifiers T2 - ACM SIGPLAN Notices Y1 - 1999 A1 - Foster, Jeffrey S. A1 - Fähndrich,M. A1 - Aiken,A. JA - ACM SIGPLAN Notices VL - 34 ER - TY - JOUR T1 - 3D motion and shape representations in visual servo control JF - The International Journal of Robotics Research Y1 - 1998 A1 - Fermüller, Cornelia A1 - Cheong, L. F A1 - Aloimonos, J. VL - 17 CP - 1 ER - TY - JOUR T1 - Ambiguity in Structure from Motion: Sphere versus Plane JF - International Journal of Computer Vision Y1 - 1998 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - If 3D rigid motion can be correctly estimated from image sequences, the structure of the scene can be correctly derived using the equations for image formation. However, an error in the estimation of 3D motion will result in the computation of a distorted version of the scene structure. Of computational interest are these regions in space where the distortions are such that the depths become negative, because in order for the scene to be visible it has to lie in front of the image, and thus the corresponding depth estimates have to be positive. The stability analysis for the structure from motion problem presented in this paper investigates the optimal relationship between the errors in the estimated translational and rotational parameters of a rigid motion that results in the estimation of a minimum number of negative depth values. The input used is the value of the flow along some direction, which is more general than optic flow or correspondence. For a planar retina it is shown that the optimal configuration is achieved when the projections of the translational and rotational errors on the image plane are perpendicular. Furthermore, the projection of the actual and the estimated translation lie on a line through the center. For a spherical retina, given a rotational error, the optimal translation is the correct one; given a translational error, the optimal rotational negative deptherror depends both in direction and value on the actual and estimated translation as well as the scene in view. The proofs, besides illuminating the confounding of translation and rotation in structure from motion, have an important application to ecological optics. The same analysis provides a computational explanation of why it is easier to estimate self-motion in the case of a spherical retina and why shape can be estimated easily in the case of a planar retina, thus suggesting that nature's design of compound eyes (or panoramic vision) for flying systems and camera-type eyes for primates (and other systems that perform manipulation) is optimal. VL - 28 SN - 0920-5691 UR - http://dx.doi.org/10.1023/A:1008063000586 CP - 2 ER - TY - CONF T1 - Approximation algorithms for multiple-tool miling T2 - Proceedings of the fourteenth annual symposium on Computational geometry Y1 - 1998 A1 - Arya,Sunil A1 - Cheng,Siu-Wing A1 - Mount, Dave JA - Proceedings of the fourteenth annual symposium on Computational geometry T3 - SCG '98 PB - ACM CY - New York, NY, USA SN - 0-89791-973-4 UR - http://doi.acm.org/10.1145/276884.276918 M3 - 10.1145/276884.276918 ER - TY - CONF T1 - Automated recovery in a secure bootstrap process T2 - Proceedings of the Symposium on Network and Distributed Systems Security (NDSS’98) Y1 - 1998 A1 - Arbaugh, William A. A1 - Keromytis,A. D A1 - Farber,D. J A1 - Smith,J. M JA - Proceedings of the Symposium on Network and Distributed Systems Security (NDSS’98) ER - TY - CONF T1 - Benchmarking a network of PCs running parallel applications T2 - Performance, Computing and Communications, 1998. IPCCC '98., IEEE International Y1 - 1998 A1 - Hollingsworth, Jeffrey K A1 - Guven, E. A1 - Akinlar, C. KW - 100 Mbit/s KW - 125 mus KW - Aerodynamics KW - Application software KW - communication micro-benchmarks KW - default mathematical libraries KW - Delay KW - Ethernet KW - Ethernet networks KW - gcc KW - latency KW - lightweight message-passing protocol KW - Linux KW - Local area networks KW - mathematics computing KW - Message passing KW - microcomputer applications KW - Microsoft Windows NT KW - NAS parallel benchmarks KW - network operating systems KW - Numerical simulation KW - parallel applications KW - PARALLEL PROCESSING KW - PC network benchmarking KW - performance comparison KW - performance evaluation KW - Personal communication networks KW - Protocols KW - PVM KW - running time KW - software libraries KW - System software KW - system software configurations KW - TCP/IP KW - TCPIP KW - Transport protocols KW - U-Net active messages KW - Visual C++ AB - Presents a benchmarking study that compares the performance of a network of four PCs connected by a 100 Mbit/s fast Ethernet running three different system software configurations: TCP/IP on Windows NT, TCP/IP on Linux and a lightweight message-passing protocol (U-Net active messages) on Linux. For each configuration, we report results for communication micro-benchmarks and the NAS (Numerical Aerodynamics Simulation) parallel benchmarks. For the NAS benchmarks, the overall running time using Linux TCP/IP was 12-500% less than the Windows NT TCP/IP configuration. Likewise, the Linux U-Net based message-passing protocol outperformed the Linux TCP/IP version by 5-200%+. We also show that, by using Linux U-Net, we are able to achieve 125 μs latency between two processes using PVM. Finally, we report that the default mathematical libraries supplied with NT (for both gcc and Visual C++) are substantially slower than the one supplied with Linux JA - Performance, Computing and Communications, 1998. IPCCC '98., IEEE International PB - IEEE SN - 0-7803-4468-5 M3 - 10.1109/PCCC.1998.659876 ER - TY - CHAP T1 - Beyond the Epipolar Constraint: Integrating 3D Motion and Structure Estimation T2 - 3D Structure from Multiple Images of Large-Scale Environments3D Structure from Multiple Images of Large-Scale Environments Y1 - 1998 A1 - Brodský,Tomáš A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Koch,Reinhard ED - Van Gool,Luc AB - This paper develops a novel solution to the problem of recovering the structure of a scene given an uncalibrated video sequence depicting the scene. The essence of the technique lies in a method for recovering the rigid transformation between the different views in the image sequence. Knowledge of this 3D motion allows for self-calibration and for subsequent recovery of 3D structure. The introduced method breaks away from applying only the traditionally used epipolar constraint and introduces a new constraint based on the interaction between 3D motion and shape. Up to now, structure from motion algorithms proceeded in two well defined steps, where the first and most important step is recovering the rigid transformation between two views, and the subsequent step is using this transformation to compute the structure of the scene in view. Here both aforementioned steps are accomplished in a synergistic manner. Existing approaches to 3D motion estimation are mostly based on the use of optic flow which however poses a problem at the locations of depth discontinuities. If we knew where depth discontinuities were, we could (using a multitude of approaches based on smoothness constraints) estimate accurately flow values for image patches corresponding to smooth scene patches; but to know the discontinuities requires solving the structure from motion problem first. In the past this dilemma has been addressed by improving the estimation of flow through sophisticated optimization techniques, whose performance often depends on the scene in view. In this paper the main idea is based on the interaction between 3D motion and shape which allows us to estimate the 3D motion while at the same time segmenting the scene. If we use a wrong 3D motion estimate to compute depth, then we obtain a distorted version of the depth function. The distortion, however, is such that the worse the motion estimate, the more likely we are to obtain depth estimates that are locally unsmooth, i.e., they vary more than the correct ones. Since local variability of depth is due either to the existence of a discontinuity or to a wrong 3D motion estimate, being able to differentiate between these two cases provides the correct motion, which yields the “smoothest” estimated depth as well as the image locations of scene discontinuities. Although no optic flow values are computed, we show that our algorithm is very much related to minimizing the epipolar constraint when the scene in view is smooth. When however the imaged scene is not smooth, the introduced constraint has in general different properties from the epipolar constraint and we present experimental results with real sequences where it performs better. JA - 3D Structure from Multiple Images of Large-Scale Environments3D Structure from Multiple Images of Large-Scale Environments T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1506 SN - 978-3-540-65310-3 UR - http://dx.doi.org/10.1007/3-540-49437-5_8 ER - TY - JOUR T1 - The design and evaluation of a high-performance earth science database JF - Parallel Computing Y1 - 1998 A1 - Shock,Carter T. A1 - Chang,Chialin A1 - Moon,Bongki A1 - Acharya,Anurag A1 - Davis, Larry S. A1 - Saltz,Joel A1 - Sussman, Alan KW - Communication KW - High-performance I/O KW - load balancing KW - scalability KW - Scientific databases AB - Earth scientists have encountered two major obstacles in their attempts to use remotely sensed imagery to analyze the earth's land cover dynamics. First, the volume of data involved is very large and second, significant preprocessing is needed before the data can be used. This is particularly so for studies that analyze global trends using data sets that cover multiple years. In this paper, we present the design of an earth science database as well as our early experiences with it. The primary design goal of this database is to facilitate efficient access to and preprocessing of large volumes of satellite data. Our initial design assumed that the main bottleneck in the system would be retrieving data from the disks. However, experimental results show that precise identification of all the data values corresponding to a query can take a significant amount of time. The problem is even more pronounced in designing the system to attempt to minimize time spent performing I/O. We therefore discuss a major redesign of the system that includes a reworking of the indexing scheme and a reorganization of the data on disks. Experimental results show that the redesigned system performs significantly better than the original system, providing interactive response times for local queries. VL - 24 SN - 0167-8191 UR - http://www.sciencedirect.com/science/article/pii/S0167819197001178 CP - 1 M3 - 10.1016/S0167-8191(97)00117-8 ER - TY - JOUR T1 - DHCP++: Applying an efficient implementation method for fail-stop cryptographic protocols JF - Proceedings of Global Internet (GlobeCom)’98 Y1 - 1998 A1 - Arbaugh, William A. A1 - Keromytis,A. D A1 - Smith,J. M ER - TY - CONF T1 - Digital dynamic telepathology–the Virtual Microscope. T2 - Proceedings of the AMIA Symposium Y1 - 1998 A1 - Afework,A. A1 - Beynon,M. D A1 - Bustamante,F. A1 - Cho,S. A1 - Demarzo,A. A1 - Ferreira,R. A1 - Miller,R. A1 - Silberman,M. A1 - Saltz, J. A1 - Sussman, Alan A1 - others JA - Proceedings of the AMIA Symposium ER - TY - JOUR T1 - Directions of Motion Fields are Hardly Ever Ambiguous JF - International Journal of Computer Vision Y1 - 1998 A1 - Brodsky, Tomas A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - If instead of the full motion field, we consider only the direction of the motion field due to a rigid motion, what can we say about the three-dimensional motion information contained in it? This paper provides a geometric analysis of this question based solely on the constraint that the depth of the surfaces in view is positive. The motivation behind this analysis is to provide a theoretical foundation for image constraints employing only the sign of flow in various directions and justify their utilization for addressing 3D dynamic vision problems. VL - 26 SN - 0920-5691 UR - http://dx.doi.org/10.1023/A:1007928406666 CP - 1 ER - TY - CHAP T1 - Drawing of Two-Dimensional Irregular Meshes T2 - Graph DrawingGraph Drawing Y1 - 1998 A1 - Aggarwal,Alok A1 - Rao Kosaraju,S. A1 - Pop, Mihai ED - Whitesides,Sue AB - We present a method for transforming two-dimensional irregular meshes into square meshes with only a constant blow up in area. We also explore context invariant transformations of irregular meshes into square meshes and provide a lower bound for the transformation of down-staircases. JA - Graph DrawingGraph Drawing T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1547 SN - 978-3-540-65473-5 UR - http://dx.doi.org/10.1007/3-540-37623-2_1 ER - TY - JOUR T1 - Effects of Errors in the Viewing Geometry on Shape Estimation JF - Computer Vision and Image Understanding Y1 - 1998 A1 - LoongFah Cheong A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - A sequence of images acquired by a moving sensor contains information about the three-dimensional motion of the sensor and the shape of the imaged scene. Interesting research during the past few years has attempted to characterize the errors that arise in computing 3D motion (egomotion estimation) as well as the errors that result in the estimation of the scene's structure (structure from motion). Previous research is characterized by the use of optic flow or correspondence of features in the analysis as well as by the employment of particular algorithms and models of the scene in recovering expressions for the resulting errors. This paper presents a geometric framework that characterizes the relationship between 3D motion and shape in the presence of errors. We examine how the three-dimensional space recovered by a moving monocular observer, whose 3D motion is estimated with some error, is distorted. We characterize the space of distortions by its level sets, that is, we characterize the systematic distortion via a family of iso-distortion surfaces, which describes the locus over which the depths of points in the scene in view are distorted by the same multiplicative factor. The framework introduced in this way has a number of applications: Since the visible surfaces have positive depth (visibility constraint), by analyzing the geometry of the regions where the distortion factor is negative, that is, where the visibility constraint is violated, we make explicit situations which are likely to give rise to ambiguities in motion estimation, independent of the algorithm used. We provide a uniqueness analysis for 3D motion analysis from normal flow. We study the constraints on egomotion, object motion, and depth for an independently moving object to be detectable by a moving observer, and we offer a quantitative account of the precision needed in an inertial sensor for accurate estimation of 3D motion. VL - 71 SN - 1077-3142 UR - http://www.sciencedirect.com/science/article/pii/S1077314297906494 CP - 3 M3 - 10.1006/cviu.1997.0649 ER - TY - JOUR T1 - Effects of Errors in the Viewing Geometry on Shape Estimation* 1,* 2 JF - Computer Vision and Image Understanding Y1 - 1998 A1 - Cheong, L. F A1 - Fermüller, Cornelia A1 - Aloimonos, J. VL - 71 CP - 3 ER - TY - JOUR T1 - Emergent patterns of teaching/learning in electronic classrooms JF - Educational Technology Research and Development Y1 - 1998 A1 - Shneiderman, Ben A1 - Borkowski,Ellen A1 - Alavi,Maryam A1 - Norman,Kent AB - Novel patterns of teaching/learning have emerged from faculty and students who use our three teaching/learning theaters at the University of Maryland, College Park. These fully-equipped electronic classrooms have been used by 74 faculty in 264 semester-long courses since the fall of 1991 with largely enthusiastic reception by both faculty and students. The designers of the teaching/learning theaters sought to provide a technologically rich environment and a support staff so that faculty could concentrate on changing the traditional lecture from its unidirectional information flow to a more collaborative activity. As faculty have evolved their personal styles in using the electronic classrooms, novel patterns of teaching/learning have emerged. In addition to enhanced lectures, we identified three common patterns: (a) active individual learning, (b) small-group collaborative learning, and (c) entire-class collaborative learning. VL - 46 SN - 1042-1629 UR - http://dx.doi.org/10.1007/BF02299671 CP - 4 ER - TY - JOUR T1 - Extension of Spherical Harmonic Method to RF Transient Regime JF - Simulation of semiconductor processes and devices 1998: SISPAD 98 Y1 - 1998 A1 - Lin,C. K. A1 - Goldsman,N. A1 - Chang,C. H. A1 - Mayergoyz, Issak D A1 - Aronowitz,S. A1 - Dong,J. A1 - Belova,N. AB - The space and time dependent electron Boltzmann transport equation (BTE)is solved sclf-consistently with the Poisson and transient hole current-continuity equation. A transient Spherical Harmonic expansion method is used to solve the BTE. By this method we can efficiently solve the BTE in the RF regime to observe how the complete distribution function responds to a rapid transient. Calculations on a BJT, which give the time dependent distribution function over a large energy range 0-3eV, throughout the device, as well as average quantities, require only 40 minutes CPU time on an Alpha workstation. ER - TY - JOUR T1 - Frequentist and Bayesian Coverage Estimations for Stratified Fault-Injection JF - DEPENDABLE COMPUTING AND FAULT TOLERANT SYSTEMS Y1 - 1998 A1 - Cukier, Michel A1 - Arlat,J. A1 - Powell,D. AB - This paper addresses the problem of estimating the coverage of fault tolerancethrough statistical processing of observations collected in fault-injection experiments. In an earlier paper, we have studied various frequentist estimation methods based on simple sampling in the whole fault/activity input space and stratified sampling in a partitioned space. In this paper, Bayesian estimation methods are introduced for stratified sampling. Two methods are presented to obtain an approximation of the posterior distribution of the coverage by calculating its moments. The moments are then used to identify the type of the distribution in the Pearson distribution system, to estimate its parameters and to obtain the coverage confidence limit. Two hypothetical example systems are used to compare the validity and the conservatism of the Bayesian and frequentist estimations. It is shown that one Bayesian estimation method is valid for both examples and that its estimations are much less conservative than the frequentist ones. However, the Bayesian estimations for stratified sampling are still conservative compared to estimations for simple sampling. VL - 11 UR - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.29.6784&rep=rep1&type=pdf ER - TY - JOUR T1 - Genetic nomenclature for Trypanosoma and Leishmania. JF - Molecular and biochemical parasitology Y1 - 1998 A1 - Clayton,C. A1 - Adams,M. A1 - Almeida,R. A1 - Baltz,T. A1 - Barrett,M. A1 - Bastien,P. A1 - Belli,S. A1 - Beverley,S. A1 - Biteau,N. A1 - Blackwell,J. A1 - others VL - 97 CP - 1-2 ER - TY - JOUR T1 - Genetic nomenclature for Trypanosoma and Leishmania. JF - Mol Biochem Parasitol Y1 - 1998 A1 - Clayton, C A1 - Adams, M A1 - Almeida, R A1 - Baltz, T A1 - Barrett, M A1 - Bastien, P A1 - Belli, S A1 - Beverley, S A1 - Biteau, N A1 - Blackwell, J A1 - Blaineau, C A1 - Boshart, M A1 - Bringaud, F A1 - Cross, G A1 - Cruz, A A1 - Degrave, W A1 - Donelson, J A1 - El-Sayed, N A1 - Fu, G A1 - Ersfeld, K A1 - Gibson, W A1 - Gull, K A1 - Ivens, A A1 - Kelly, J A1 - Vanhamme, L KW - Animals KW - Leishmania KW - Terminology as Topic KW - Trypanosoma VL - 97 CP - 1-2 ER - TY - RPRT T1 - On the geometry of visual correspondence Y1 - 1998 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - Image displacement fieldsoptical flow fields, stereo disparity fields, normal flow fieldsdue to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constraine d to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The go al of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views. JA - Technical Reports of the Computer Science Department ER - TY - RPRT T1 - An On-line Variable Length Binary Encoding Y1 - 1998 A1 - Acharya,Tinku A1 - JaJa, Joseph F. KW - Technical Report AB - We present a methodology of an on-line variable-length binaryencoding of a set of integers. The basic principle of this methodology is to maintain the prefix property amongst the codes assigned on-line to a set of integers growing dynamically. The prefix property enables unique decoding of a string of elements from this set. To show the utility of this on-line variable length binary encoding, we apply this methodology to encode the LZW codes. Application of this encoding scheme significantly improves the compression achieved by the standard LZW scheme. This encoding can be applied in other compression schemes to encode the pointers using variable-length binary codes. (Also cross-referenced as UMIACS-TR-95-39) PB - Instititue for Advanced Computer Studies, Univ of Maryland, College Park VL - UMIACS-TR-95-39 UR - http://drum.lib.umd.edu/handle/1903/714 ER - TY - JOUR T1 - An optimal algorithm for approximate nearest neighbor searching fixed dimensions JF - Journal of the ACM (JACM) Y1 - 1998 A1 - Arya,Sunil A1 - Mount, Dave A1 - Netanyahu,Nathan S. A1 - Silverman,Ruth A1 - Wu,Angela Y. KW - Approximation algorithms KW - Box-decomposition trees KW - closet-point queries KW - nearest neighbor searching KW - post-office problem KW - priority search AB - Consider a set of S of n data points in real d-dimensional space, Rd, where distances are measured using any Minkowski metric. In nearest neighbor searching, we preprocess S into a data structure, so that given any query point q ∈ Rd, is the closest point of S to q can be reported quickly. Given any positive real &egr;, data point p is a (1 +&egr;)-approximate nearest neighbor of q if its distance from q is within a factor of (1 + &egr;) of the distance to the true nearest neighbor. We show that it is possible to preprocess a set of n points in Rd in O(dn log n) time and O(dn) space, so that given a query point q ∈ Rd, and &egr; > 0, a (1 + &egr;)-approximate nearest neighbor of q can be computed in O(cd, &egr; log n) time, where cd,&egr;≤d 1 + 6d/e;d is a factor depending only on dimension and &egr;. In general, we show that given an integer k ≥ 1, (1 + &egr;)-approximations to the k nearest neighbors of q can be computed in additional O(kd log n) time. VL - 45 SN - 0004-5411 UR - http://doi.acm.org/10.1145/293347.293348 CP - 6 M3 - 10.1145/293347.293348 ER - TY - CONF T1 - Partial online cycle elimination in inclusion constraint graphs T2 - ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI) Y1 - 1998 A1 - Aiken,A. A1 - Fhndrich,M. A1 - Foster, Jeffrey S. A1 - Su,Z. JA - ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI) ER - TY - CONF T1 - Performance measurement using low perturbation and high precision hardware assists T2 - , The 19th IEEE Real-Time Systems Symposium, 1998. Proceedings Y1 - 1998 A1 - Mink, A. A1 - Salamon, W. A1 - Hollingsworth, Jeffrey K A1 - Arunachalam, R. KW - Clocks KW - Computerized monitoring KW - Counting circuits KW - Debugging KW - Hardware KW - hardware performance monitor KW - high precision hardware assists KW - low perturbation KW - measurement KW - MPI message passing library KW - MultiKron hardware performance monitor KW - MultiKron PCI KW - NIST KW - online performance monitoring tools KW - Paradyn parallel performance measurement tools KW - PCI bus slot KW - performance bug KW - performance evaluation KW - performance measurement KW - program debugging KW - program testing KW - real-time systems KW - Runtime KW - Timing AB - We present the design and implementation of MultiKron PCI, a hardware performance monitor that can be plugged into any computer with a free PCI bus slot. The monitor provides a series of high-resolution timers, and the ability to monitor the utilization of the PCI bus. We also demonstrate how the monitor can be integrated with online performance monitoring tools such as the Paradyn parallel performance measurement tools to improve the overhead of key timer operations by a factor of 25. In addition, we present a series of case studies using the MultiKron hardware performance monitor to measure and tune high-performance parallel completing applications. By using the monitor, we were able to find and correct a performance bug in a popular implementation of the MPI message passing library that caused some communication primitives to run at one half their potential speed JA - , The 19th IEEE Real-Time Systems Symposium, 1998. Proceedings PB - IEEE SN - 0-8186-9212-X M3 - 10.1109/REAL.1998.739771 ER - TY - JOUR T1 - The PLAN system for building Active Networks JF - University of Pennsylvania (February 27, 1998) Y1 - 1998 A1 - Hicks, Michael W. A1 - Kakkar,P. A1 - Moore,J. T A1 - Gunter,C. A A1 - Alexander,D. S A1 - Nettles,S. ER - TY - JOUR T1 - Safety and security of programmable network infrastructures JF - IEEE Communications Magazine Y1 - 1998 A1 - Alexander,S. A1 - Arbaugh, William A. A1 - Keromytis,A. D A1 - Smith,J. M KW - Access control KW - error protection KW - IP networks KW - Multicast protocols KW - network architecture KW - network operating systems KW - network service model KW - operating system KW - Power system dynamics KW - Power system modeling KW - Power system reliability KW - programmable languages KW - programmable network infrastructures KW - programming languages KW - Proposals KW - Protection KW - reliability properties KW - Safety KW - Secure Active Network Environment KW - Security KW - security of data KW - service creation KW - service providers KW - Switches KW - telecommunication computing KW - telecommunication network reliability KW - Web and internet services AB - Safety and security are two reliability properties of a system. A “safe” system provides protection against errors of trusted users, while a “secure” system protects against errors introduced by untrusted users. There is considerable overlap between mechanisms to support each property. Requirements for rapid service creation have stimulated the development of programmable network infrastructures, where end users or service providers can customize the properties of a network infrastructure while it continues to operate. A central concern of potential users of such systems is their reliability and, most specifically, their safety and security. In this article we explain the impact the network service model and architecture have on safety and security, and provide a model with which policies can be translated into restrictions of a general system. We illustrate these ideas with the Secure Active Network Environment (SANE) architecture, which provides a means of controlling access to the functions provided by any programmable infrastructure VL - 36 SN - 0163-6804 CP - 10 M3 - 10.1109/35.722141 ER - TY - JOUR T1 - Salient Frame Detection for Molecular Dynamics Simulations JF - Scientific Visualization: Interactions, Features, Metaphors Y1 - 1998 A1 - Kim,Y. A1 - Patro,R. A1 - Ip,C. Y A1 - O’Leary,D. P A1 - Anishkin,A. A1 - Sukharev,S. A1 - Varshney, Amitabh AB - Saliency-based analysis can be applied to time-varying 3D datasetsfor the purpose of summarization, abstraction, and motion analysis. As the sizes of time-varying datasets continue to grow, it becomes more and more difficult to comprehend vast amounts of data and information in a short period of time. Au- tomatically generated thumbnail images and previewing of time-varying datasets can help viewers explore and understand the datasets significantly faster as well as provide new insights. In this paper, we introduce a novel method for detect- ing salient frames for molecular dynamics simulations. Our method effectively detects crucial transitions in simulated mechanosensitive ion channel (MscS), in agreement with experimental data. VL - 2 ER - TY - JOUR T1 - Scheduling Aperiodic and Sporadic Tasks in Hard Real-Time Systems JF - Technical Reports from UMIACS, UMIACS-TR-97-44 Y1 - 1998 A1 - Choi,Seonho A1 - Agrawala, Ashok K. KW - Technical Report AB - The stringent timing constraints as well as the functional correctnessare essential requirements of hard real-time systems. In such systems, scheduling plays a very important role in satisfying these constraints. The priority based scheduling schemes have been used commonly due to the simplicity of the scheduling algorithm. However, in the presence of task interdependencies and complex timing constraints, such scheduling schemes may not be appropriate due to the lack of an efficient mechanism to schedule them and to carry out the schedulability analysis. In contrast, the time based scheduling scheme may be used to schedule a set of tasks with greater degree of schedulability achieved at a cost of higher complexity of off-line scheduling. One of the drawbacks of currently available scheduling schemes, however, is known to be their inflexibility in dynamic environments where dynamic processes exist, such as aperiodic and sporadic processes. We develop and analyze scheduling schemes which efficiently provide the flexibility required in real-time systems for scheduling processes arriving dynamically. This enables static hard periodic processes and dynamic processes(aperiodic or sporadic) to be jointly scheduled. (Also cross-referenced as UMIACS-TR-97-44) UR - http://drum.lib.umd.edu/handle/1903/900 ER - TY - JOUR T1 - A secure active network environment architecture: realization in SwitchWare JF - IEEE Network Y1 - 1998 A1 - Alexander,D. S A1 - Arbaugh, William A. A1 - Keromytis,A. D A1 - Smith,J. M KW - access protocols KW - AEGIS secure bootstrap architecture KW - architecture KW - Authentication KW - Collaboration KW - Communication switching KW - dynamic integrity checks KW - extended LAN KW - Functional programming KW - implementation KW - integrity KW - Intelligent networks KW - IP networks KW - Local area networks KW - network infrastructure KW - network infrastructures KW - network operating systems KW - network-level solutions KW - node KW - node-to-node authentication KW - packet switching KW - Proposals KW - ramming system KW - SANE KW - secure active network environment architecture KW - security of data KW - Switches KW - SwitchWare KW - trusted state KW - Web and internet services AB - An active network is a network infrastructure which is programmable on a per-user or even per-packet basis. Increasing the flexibility of such network infrastructures invites new security risks. Coping with these security risks represents the most fundamental contribution of active network research. The security concerns can be divided into those which affect the network as a whole and those which affect individual elements. It is clear that the element problems must be solved first, since the integrity of network-level solutions will be based on trust in the network elements. In this article we describe the architecture and implementation of a secure active network environment (SANE), which we believe provides a basis for implementing secure network-level solutions. We guarantee that a node begins operation in a trusted state with the AEGIS secure bootstrap architecture. We guarantee that the system remains in a trusted state by applying dynamic integrity checks in the network element's runtime system, using a novel naming system, and applying node-to-node authentication when needed. The construction of an extended LAN is discussed VL - 12 SN - 0890-8044 CP - 3 M3 - 10.1109/65.690960 ER - TY - JOUR T1 - Security for virtual private intranets JF - Computer Y1 - 1998 A1 - Arbaugh, William A. A1 - Davin,J. R A1 - Farber,D. J A1 - Smith,J. M KW - businesses KW - Clouds KW - Companies KW - core operating system components KW - cryptography KW - Data security KW - employee homes KW - encryption KW - functional roles KW - hard drive KW - Home computing KW - home working KW - integrity checking KW - Internet KW - Local area networks KW - multiple personalities KW - network authentication KW - network environment KW - operating system modifications KW - Operating systems KW - Roads KW - secure identity based lending KW - security management KW - security of data KW - shared applications KW - SIBL KW - single hardware platform KW - smart cards KW - symmetric algorithm KW - system partition KW - telecommuting KW - Teleworking KW - trust relationship KW - trustworthy system KW - virtual private intranets AB - As telecommuting grows, businesses must consider security when extending their network environment to employees' homes. Researchers at the University of Pennsylvania have addressed the problem with smart cards, operating system modifications, and network authentication. We note the distinction between trust and integrity: trust is determined through the verification of components and the dependencies among them, while integrity demonstrates that components haven't been modified. Thus integrity checking in a trustworthy system is about preserving an established trust or trust relationship. Our solution to the challenge of isolating functional roles that may share a single hardware platform is called secure identity based lending (SIBL). SIBL provides multiple personalities by partitioning the hard drive into n+1 partitions, where n is the number of supported personalities. All personalities use the system partition for core operating system components and shared applications. Each of the personalities is also associated with one of the remaining partitions, which are encrypted using a symmetric algorithm VL - 31 SN - 0018-9162 CP - 9 M3 - 10.1109/2.708450 ER - TY - CONF T1 - Self-calibration from image derivatives T2 - Sixth International Conference on Computer Vision, 1998 Y1 - 1998 A1 - Brodsky, T. A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D-rotation KW - active vision KW - Calibration KW - CAMERAS KW - discrete motion KW - Encoding KW - Equations KW - image derivatives KW - image formation KW - image measurements KW - Image motion analysis KW - image motion fields KW - Image reconstruction KW - Image sequences KW - large video databases KW - Layout KW - Levenberg-Marquardt parameter estimation KW - linear pinhole-camera model KW - Motion estimation KW - Motion measurement KW - Optical computing KW - parameter estimation KW - projective transformation KW - rigidly moving camera KW - self-calibration KW - smoothness constraints KW - unknown calibration parameters AB - This study investigates the problem of estimating the calibration parameters from image motion fields induced by a rigidly moving camera with unknown calibration parameters, where the image formation is modeled with a linear pinhole-camera model. The equations obtained show the flow to be clearly separated into a component due to the translation and the calibration parameters and a component due to the rotation and the calibration parameters. A set of parameters encoding the latter component are linearly related to the flow, and from these parameters the calibration can be determined. However, as for discrete motion, in the general case it is not possible, to decouple image measurements from two frames only into their translational and rotational component. Geometrically, the ambiguity takes the form of a part of the rotational component being parallel to the translational component, and thus the scene can be reconstructed only up to a projective transformation. In general, for a full calibration at least four successive image frames are necessary with the 3D-rotation changing between the measurements. The geometric analysis gives rise to a direct self-calibration method that avoids computation of optical flow or point correspondences and uses only normal flow measurements. In this technique the direction of translation is estimated employing in a novel way smoothness constraints. Then the calibration parameters are estimated from the rotational components of several flow fields using Levenberg-Marquardt parameter estimation, iterative in the calibration parameters only. The technique proposed does not require calibration objects in the scene or special camera motions and it also avoids the computation of exact correspondence. This makes it suitable for the calibration of active vision systems which have to acquire knowledge about their intrinsic parameters while they perform other tasks, or as a tool for analyzing image sequences in large video databases JA - Sixth International Conference on Computer Vision, 1998 PB - IEEE SN - 81-7319-221-9 M3 - 10.1109/ICCV.1998.710704 ER - TY - JOUR T1 - Shape from video: Beyond the epipolar constraint JF - Proceedings of the DARPA Image Understanding Workshop Y1 - 1998 A1 - Brodsky, T. A1 - Fermüller, Cornelia A1 - Aloimonos, J. ER - TY - CHAP T1 - Simultaneous estimation of viewing geometry and structure T2 - Computer Vision — ECCV'98Computer Vision — ECCV'98 Y1 - 1998 A1 - Brodský,Tomáš A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Burkhardt,Hans ED - Neumann,Bernd AB - Up to now, structure from motion algorithms proceeded in two well defined steps, where the first and most important step is recovering the rigid transformation between two views, and the subsequent step is using this transformation to compute the structure of the scene in view. This paper introduces a novel approach to structure from motion in which both aforementioned steps are accomplished in a synergistic manner. Existing approaches to 3D motion estimation are mostly based on the use of optic flow which however poses a problem at the locations of depth discontinuities. If we knew where depth discontinuities were, we could (using a multitude of approaches based on smoothness constraints) estimate accurately flow values for image patches corresponding to smooth scene patches; but to know the discontinuities requires solving the structure from motion problem first. In the past this dilemma has been addressed by improving the estimation of flow through sophisticated optimization techniques, whose performance often depends on the scene in view. In this paper we follow a different approach. The main idea is based on the interaction between 3D motion and shape which allows us to estimate the 3D motion while at the same time segmenting the scene. If we use a wrong 3D motion estimate to compute depth, then we obtain a distorted version of the depth function. The distortion, however, is such that the worse the motion estimate, the more likely we are to obtain depth estimates that are locally unsmooth, i.e., they vary more than the correct ones. Since local variability of depth is due either to the existence of a discontinuity or to a wrong 3D motion estimate, being able to differentiate between these two cases provides the correct motion, which yields the “smoothest” estimated depth as well as the image location of scene discontinuities. Although no optic flow values are computed, we show that our algorithm is very much related to minimizing the epipolar constraint and we present a number of experimental results with real image sequences indicating the robustness of the method. JA - Computer Vision — ECCV'98Computer Vision — ECCV'98 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1406 SN - 978-3-540-64569-6 UR - http://dx.doi.org/10.1007/BFb0055677 ER - TY - JOUR T1 - The SwitchWare active network architecture JF - IEEE Network Y1 - 1998 A1 - Alexander,D. S A1 - Arbaugh, William A. A1 - Hicks, Michael W. A1 - Kakkar,P. A1 - Keromytis,A. D A1 - Moore,J. T A1 - Gunter,C. A A1 - Nettles,S. M A1 - Smith,J. M KW - active extensions KW - active packets KW - Authentication KW - Computer languages KW - Computer networks KW - cryptography KW - cryptography-based authentication KW - high-integrity base KW - integrity checking KW - IP networks KW - LAN interconnection KW - mobile programs KW - network operating systems KW - packet switching KW - programmable network infrastructure KW - programming languages KW - Protocols KW - Safety KW - safety requirements KW - scalability KW - secure active router infrastructure KW - Security KW - security requirements KW - services KW - strong type checking KW - Switches KW - SwitchWare active network architecture KW - telecommunication network routing KW - Tin KW - usability KW - verification techniques AB - Active networks must balance the flexibility of a programmable network infrastructure against the safety and security requirements inherent in sharing that infrastructure. Furthermore, this balance must be achieved while maintaining the usability of the network. The SwitchWare active network architecture is a novel approach to achieving this balance using three layers: active packets, which contain mobile programs that replace traditional packets; active extensions, which provide services on the network elements and can be dynamically loaded; and a secure active router infrastructure, which forms a high-integrity base on which the security of the other layers depends. In addition to integrity checking and cryptography-based authentication, security in our architecture depends heavily on verification techniques from programming languages, such as strong type checking VL - 12 SN - 0890-8044 CP - 3 M3 - 10.1109/65.690959 ER - TY - JOUR T1 - The switchware active network implementation JF - The ML Workshop, International Conference on Functional Programming (ICFP) Y1 - 1998 A1 - Alexander,D. S A1 - Hicks, Michael W. A1 - Kakkar,P. A1 - Keromytis,A. D A1 - Shaw,M. A1 - Moore,J. T A1 - Gunter,C. A A1 - Jim,T. A1 - Nettles,S. M A1 - Smith,J. M ER - TY - JOUR T1 - T2 JF - ACM SIGMOD Record Y1 - 1998 A1 - Chang,Chialin A1 - Acharya,Anurag A1 - Sussman, Alan A1 - Saltz,Joel VL - 27 SN - 01635808 UR - http://dl.acm.org/citation.cfm?id=273264 M3 - 10.1145/273244.273264 ER - TY - CONF T1 - Temporally determinate disk access (extended abstract): an experimental approach T2 - Proceedings of the 1998 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems Y1 - 1998 A1 - Aboutabl,Mohamed A1 - Agrawala, Ashok K. A1 - Decotignie,Jean-Dominique JA - Proceedings of the 1998 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems T3 - SIGMETRICS '98/PERFORMANCE '98 PB - ACM CY - New York, NY, USA SN - 0-89791-982-3 UR - http://doi.acm.org/10.1145/277851.277950 M3 - 10.1145/277851.277950 ER - TY - BOOK T1 - Trends in the Early Careers of Life Scientists Y1 - 1998 A1 - Tilghman,S A1 - Astin,HS A1 - Brinkley,W A1 - Chilton,MD A1 - Cummings, Michael P. A1 - Ehrenberg,RG A1 - Fox,MF A1 - Glenn,K A1 - Green,PJ A1 - Hans,S A1 - Kelman,A A1 - LaPidus,J A1 - Levin,B A1 - McIntosh,JR A1 - Riecken,H A1 - Stephen,PE PB - National Academy Press CY - Washington, DC ER - TY - JOUR T1 - Trends in the early careers of life scientists - Preface and executive summary JF - Mol Biol Cell Y1 - 1998 A1 - Tilghman,S A1 - Astin,HS A1 - Brinkley,W A1 - Chilton,MD A1 - Cummings, Michael P. A1 - Ehrenberg,RG A1 - Fox,MF A1 - Glenn,K A1 - Green,PJ A1 - Hans,S A1 - Kelman,A A1 - LaPidus,J A1 - Levin,B A1 - McIntosh,JR A1 - Riecken,H A1 - Stephen,PE VL - 9 CP - 11 ER - TY - JOUR T1 - Uncertainty propagation in model-based recognition JF - International Journal of Computer Vision Y1 - 1998 A1 - Alter,T. D. A1 - Jacobs, David W. AB - Robust recognition systems require a careful understanding of the effects of error in sensed features. In model-based recognition, matches between model features and sensed image features typically are used to compute a model pose and then project the unmatched model features into the image. The error in the image features results in uncertainty in the projected model features. We first show how error propagates when poses are based on three pairs of 3D model and 2D image points. In particular, we show how to simply and efficiently compute the distributed region in the image where an unmatched model point might appear, for both Gaussian and bounded error in the detection of image points, and for both scaled-orthographic and perspective projection models. Next, we provide geometric and experimental analyses to indicate when this linear approximation will succeed and when it will fail. Then, based on the linear approximation, we show how we can utilize Linear Programming to compute bounded propagated error regions for any number of initial matches. Finally, we use these results to extend, from two-dimensional to three-dimensional objects, robust implementations of alignment, interpretation-tree search, and transformation clustering. VL - 27 CP - 2 M3 - 10.1023/A:1007989016491 ER - TY - CHAP T1 - The Video Yardstick T2 - Modelling and Motion Capture Techniques for Virtual EnvironmentsModelling and Motion Capture Techniques for Virtual Environments Y1 - 1998 A1 - Brodský,Tomáš A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Magnenat-Thalmann,Nadia ED - Thalmann,Daniel AB - Given uncalibrated video sequences, how can we recover rich descriptions of the scene content, beyond two-dimensional (2D) measurements such as color/texture or motion fields — descriptions of shape and three-dimensional (3D) motion? This is the well known structure from motion (SFM) problem. Up to now, SFM algorithms proceeded in two well defined steps, where the first and most important step is recovering the rigid transformation between two views, and the subsequent step is using this transformation to compute the structure of the scene in view. This paper introduces a novel approach to structure from motion in which both steps are accomplished in a synergistic manner. It deals with the classical structure from motion problem considering a calibrated camera as well as the extension to an uncalibrated optical device. Existing approaches to estimation of the viewing geometry are mostly based on the use of optic flow, which, however, poses a problem at the locations of depth discontinuities. If we knew where depth discontinuities were, we could (using a multitude of approaches based on smoothness constraints) accurately estimate flow values for image patches corresponding to smooth scene patches; but to know the discontinuities requires solving the structure from motion problem first. In the past this dilemma has been addressed by improving the estimation of flow through sophisticated optimization techniques, whose performance often depends on the scene in view. In this paper we follow a different approach. We directly utilize the image derivatives and employ constraints which involve the 3D motion and shape of the scene, leading to a geometric and statistical estimation problem. The main idea is based on the interaction between 3D motion and shape which allows us to estimate the 3D motion while at the same time segmenting the scene. If we use a wrong 3D motion estimate to compute depth, we obtain a distorted version of the depth function. The distortion, however, is such that the worse the motion estimate, the more likely we are to obtain depth estimates that are locally unsmooth, i.e., they vary more than the correct ones. Since local variability of depth is due either to the existence of a discontinuity or to a wrong 3D motion estimate, being able to differentiate between these two cases provides the correct motion, which yields the “smoothest” estimated depth as well as the image locations of scene discontinuities. We analyze the new constraints introduced by our approach and show their relationship to the minimization of the epipolar constraint, which becomes a special case of our theory. Finally, we present a number of experimental results with real image sequences indicating the robustness of our method and the improvement over traditional methods. The resulting system is a video yardstick that can be applied to any video sequence to recover first the calibration parameters of the camera that captured the video and, subsequently, the structure of the scene. JA - Modelling and Motion Capture Techniques for Virtual EnvironmentsModelling and Motion Capture Techniques for Virtual Environments T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1537 SN - 978-3-540-65353-0 UR - http://dx.doi.org/10.1007/3-540-49384-0_12 ER - TY - JOUR T1 - Viewing personal history records: A comparison of tabular format and graphical presentation using LifeLines JF - Behaviour & Information Technology Y1 - 1998 A1 - Alonso,Diane Lindwarm A1 - Rose,Anne A1 - Plaisant, Catherine A1 - Norman,Kent L AB - Thirty-six participants used a static version of either LifeLines, a graphical interface, or a tabular representation to answer questions about a database of temporal personal history information. Results suggest that overall the LifeLines representation led to much faster response times, primarily for questions which involved interval comparisons and making intercategorical connections. A 'first impression' test showed that LifeLines can reduce some of the biases of the tabular record summary. A post-experimental memory test led to significantly (p< 0.004) higher recall for LifeLines. Finally, simple interaction techniques are proposed to compensate for the problems of the static LifeLines display's ability to deal with precise dates, attribute coding and overlaps.Thirty-six participants used a static version of either LifeLines, a graphical interface, or a tabular representation to answer questions about a database of temporal personal history information. Results suggest that overall the LifeLines representation led to much faster response times, primarily for questions which involved interval comparisons and making intercategorical connections. A 'first impression' test showed that LifeLines can reduce some of the biases of the tabular record summary. A post-experimental memory test led to significantly (p< 0.004) higher recall for LifeLines. Finally, simple interaction techniques are proposed to compensate for the problems of the static LifeLines display's ability to deal with precise dates, attribute coding and overlaps. VL - 17 SN - 0144-929X UR - http://www.tandfonline.com/doi/abs/10.1080/014492998119328 CP - 5 M3 - 10.1080/014492998119328 ER - TY - CHAP T1 - What is computed by structure from motion algorithms? T2 - Computer Vision — ECCV'98 Y1 - 1998 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Burkhardt,Hans ED - Neumann,Bernd AB - In the literature we find two classes of algorithms which, on the basis of two views of a scene, recover the rigid transformation between the views and subsequently the structure of the scene. The first class contains techniques which require knowledge of the correspondence or the motion field between the images and are based on the epipolar constraint. The second class contains so-called direct algorithms which require knowledge about the value of the flow in one direction only and are based on the positive depth constraint. Algorithms in the first class achieve the solution by minimizing a function representing deviation from the epipolar constraint while direct algorithms find the 3D motion that, when used to estimate depth, produces a minimum number of negative depth values. This paper presents a stability analysis of both classes of algorithms. The formulation is such that it allows comparison of the robustness of algorithms in the two classes as well as within each class. Specifically, a general statistical model is employed to express the functions which measure the deviation from the epipolar constraint and the number of negative depth values, and these functions are studied with regard to their topographic structure, specifically as regards the errors in the 3D motion parameters at the places representing the minima of the functions. The analysis shows that for algorithms in both classes which estimate all motion parameters simultaneously, the obtained solution has an error such that the projections of the translational and rotational errors on the image plane are perpendicular to each other. Furthermore, the estimated projection of the translation on the image lies on a line through the origin and the projection of the real translation. JA - Computer Vision — ECCV'98 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1406 SN - 978-3-540-64569-6 UR - http://dx.doi.org/10.1007/BFb0055678 ER - TY - CONF T1 - Which shape from motion? T2 - Sixth International Conference on Computer Vision, 1998 Y1 - 1998 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion estimation KW - affine shape KW - Algorithm design and analysis KW - Computer vision KW - distorted version KW - distortion function KW - human visual space distortion KW - HUMANS KW - Image motion analysis KW - image representation KW - Information analysis KW - Layout KW - Motion analysis KW - Motion estimation KW - motion information KW - Psychology KW - rigid transformation KW - SHAPE KW - shape estimation KW - shape representations KW - State estimation KW - visual space AB - In a practical situation, the rigid transformation relating different views is recovered with errors. In such a case, the recovered depth of the scene contains errors, and consequently a distorted version of visual space is computed. What then are meaningful shape representations that can be computed from the images? The result presented in this paper states that if the rigid transformation between different views is estimated in a way that gives rise to a minimum number of negative depth values, then at the center of the image affine shape can be correctly computed. This result is obtained by exploiting properties of the distortion function. The distortion model turns out to be a very powerful tool in the analysis and design of 3D motion and shape estimation algorithms, and as a byproduct of our analysis we present a computational explanation of psychophysical results demonstrating human visual space distortion from motion information JA - Sixth International Conference on Computer Vision, 1998 PB - IEEE SN - 81-7319-221-9 M3 - 10.1109/ICCV.1998.710792 ER - TY - JOUR T1 - ANN: A library for approximate nearest neighbor searching JF - CGC 2nd Annual Fall Workshop on Computational Geometry Y1 - 1997 A1 - Mount, Dave A1 - Arya,S. ER - TY - CONF T1 - Approximating hyper-rectangles: learning and pseudo-random sets T2 - Proceedings of the twenty-ninth annual ACM symposium on Theory of computing Y1 - 1997 A1 - Auer,Peter A1 - Long,Philip M. A1 - Srinivasan, Aravind KW - approximations of distributions KW - derandomization KW - explicit constructions KW - machine learning KW - multiple-instance learning KW - PAC learning KW - pseudorandomness KW - Ramsey graphs KW - random graphs KW - rectangles KW - sample complexity JA - Proceedings of the twenty-ninth annual ACM symposium on Theory of computing T3 - STOC '97 PB - ACM CY - New York, NY, USA SN - 0-89791-888-6 UR - http://doi.acm.org/10.1145/258533.258611 M3 - 10.1145/258533.258611 ER - TY - CONF T1 - The confounding of translation and rotation in reconstruction from multiple views T2 - , 1997 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 1997. Proceedings Y1 - 1997 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D rigid motion KW - CAMERAS KW - ecological optics KW - Error correction KW - Image motion analysis KW - Image reconstruction KW - Layout KW - Motion analysis KW - Motion estimation KW - multiple views KW - Optical distortion KW - optimal configuration KW - optimal rotational error KW - planar retina KW - RETINA KW - rigid motion KW - ROTATION KW - scene structure KW - shape estimation KW - spherical retina KW - Stability analysis KW - structure-from-motion problem KW - translation AB - If 3D rigid motion is estimated with some error a distorted version of the scene structure will in turn be computed. Of computational interest are these regions in space where the distortions are such that the depths become negative, because in order to be visible the scene has to lie in front of the image. The stability analysis for the structure-from-motion problem presented in this paper investigates the optimal relationship between the errors in the estimated translational and rotational parameters of a rigid motion, that results in the estimation of a minimum number of negative depth values. The input used is the value of the flow along some direction, which is more general than optic flow or correspondence. For a planar retina it is shown that the optimal configuration is achieved when the projections of the translational and rotational errors on the image plane are perpendicular. Furthermore, the projection of the actual and the estimated translation lie on a line passing through the image center. For a spherical retina given a rotational error, the optimal translation is the correct one, while given a translational error. The optimal rotational error is normal to the translational one at an equal distance from the real and estimated translations. The proofs, besides illuminating the confounding of translation and rotation in structure from motion, have an important application to ecological optics, explaining differences of planar and spherical eye or camera designs in motion and shape estimation JA - , 1997 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 1997. Proceedings PB - IEEE SN - 0-8186-7822-4 M3 - 10.1109/CVPR.1997.609328 ER - TY - JOUR T1 - DIRECT MOTION PERCEPTION JF - Visual navigation: from biological systems to unmanned ground vehicles Y1 - 1997 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ER - TY - CONF T1 - The distributed information search component (disco) and the world wide web T2 - Proc. of ACM SIGMOD Conf. on Management of Data Y1 - 1997 A1 - Naacke,H. A1 - Kapitskaia,O. A1 - Tomasic,A. A1 - Bonnet,P. A1 - Raschid, Louiqa A1 - Amouroux,R. JA - Proc. of ACM SIGMOD Conf. on Management of Data ER - TY - JOUR T1 - Editorial: Evaluation and assessment in software engineering JF - Information and Software Technology Y1 - 1997 A1 - Kitchenham,B. A1 - Brereton,P. A1 - Budgen,D. A1 - Linkman,S. A1 - Almstrum,V. L A1 - Pfleeger,S. L A1 - Zelkowitz, Marvin V A1 - Wallace,D. VL - 39 CP - 11 ER - TY - JOUR T1 - Families of Stationary Patterns Producing Illusory Movement: Insights into the Visual System JF - Proceedings of the Royal Society of London. Series B: Biological SciencesProc. R. Soc. Lond. B Y1 - 1997 A1 - Fermüller, Cornelia A1 - Pless,Robert A1 - Aloimonos, J. AB - A computational explanation of the illusory movement experienced upon extended viewing of Enigma, a static figure painted by Leviant, is presented. The explanation relies on a model for the interpretation of three–dimensional motion information contained in retinal motion measurements. This model shows that the Enigma figure is a special case of a larger class of figures exhibiting the same illusory movement and these figures are introduced here. Our explanation suggests that eye movements and/or accommodation changes cause weak retinal motion signals, which are interpreted by higher–level processes in a way that gives rise to these illusions, and proposes a number of new experiments to unravel the functional structure of the motion pathway. VL - 264 SN - 0962-8452, 1471-2954 UR - http://rspb.royalsocietypublishing.org/content/264/1383/795 CP - 1383 M3 - 10.1098/rspb.1997.0112 ER - TY - JOUR T1 - On the Geometry of Visual Correspondence JF - International Journal of Computer Vision Y1 - 1997 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - Image displacement fields—optical flow fields, stereo disparity fields, normal flow fields—due to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constrained to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The goal of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views. VL - 21 SN - 0920-5691 UR - http://dx.doi.org/10.1023/A:1007951901001 CP - 3 ER - TY - CHAP T1 - The geometry of visual space distortion T2 - Algebraic Frames for the Perception-Action CycleAlgebraic Frames for the Perception-Action Cycle Y1 - 1997 A1 - Fermüller, Cornelia A1 - LoongFah Cheong A1 - Aloimonos, J. ED - Sommer,Gerald ED - Koenderink,Jan AB - The encounter of perception and action happens at the intermediate representations of space-time. In many of the computational models employed in the past, it has been assumed that a metric representation of physical space can be derived by visual means. Psychophysical experiments, as well as computational considerations, can convince us that the perception of space and shape has a much more complicated nature, and that only a distorted version of actual, physical space can be computed. This paper develops a computational geometric model that explains why such distortion might take place. The basic idea is that, both in stereo and motion, we perceive the world from multiple views. Given the rigid transformation between the views and the properties of the image correspondence, the depth of the scene can be obtained. Even a slight error in the rigid transformation parameters causes distortion of the computed depth of the scene. The unified framework introduced here describes this distortion in computational terms. We characterize the space of distortions by its level sets, that is, we characterize the systematic distortion via a family of iso-distortion surfaces which describes the locus over which depths are distorted by some multiplicative factor. Clearly, functions of the distorted space exhibiting some sort of invariance, produce desirable representations for biological and artificial systems [13]. Given that humans' estimation of egomotion or estimation of the extrinsic parameters of the stereo apparatus is likely to be imprecise, the framework is used to explain a number of psychophysical experiments on the perception of depth from motion or stereo. JA - Algebraic Frames for the Perception-Action CycleAlgebraic Frames for the Perception-Action Cycle T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1315 SN - 978-3-540-63517-8 UR - http://dx.doi.org/10.1007/BFb0017872 ER - TY - JOUR T1 - Improved parallel approximation of a class of integer programming problems JF - Algorithmica Y1 - 1997 A1 - Alon,N. A1 - Srinivasan, Aravind AB - We present a method to derandomize RNC algorithms, converting them to NC algorithms. Using it, we show how to approximate a class of NP-hard integer programming problems in NC , to within factors better than the current-best NC algorithms (of Berger and Rompel and Motwani et al. ); in some cases, the approximation factors are as good as the best-known sequential algorithms, due to Raghavan. This class includes problems such as global wire-routing in VLSI gate arrays and a generalization of telephone network planning in SONET rings. Also for a subfamily of the “packing” integer programs, we provide the first NC approximation algorithms; this includes problems such as maximum matchings in hypergraphs, and generalizations. The key to the utility of our method is that it involves sums of superpolynomially many terms, which can however be computed in NC ; this superpolynomiality is the bottleneck for some earlier approaches, due to Berger and Rompel and Motwani et al. VL - 17 SN - 0178-4617 UR - http://dx.doi.org/10.1007/BF02523683 CP - 4 ER - TY - JOUR T1 - A Language Identification Application Built on the Java Client/Server Platform JF - From Research to Commercial Applications: Making NLP Work in Practice Y1 - 1997 A1 - Adams,G. A1 - Resnik, Philip ER - TY - JOUR T1 - Local Rules for Protein Folding on a Triangular Lattice and Generalized Hydrophobicity in the HP Model JF - Journal of Computational Biology Y1 - 1997 A1 - Agarwala,Richa A1 - Batzoglou,Serafim A1 - DančíK,Vlado A1 - Decatur,Scott E. A1 - Hannenhalli, Sridhar A1 - Farach,Martin A1 - Muthukrishnan,S. A1 - Skiena,Steven AB - We consider the problem of determining the three-dimensional folding of a protein given its one-dimensional amino acid sequence. We use the HP model for protein folding proposed by Dill (1985), which models protein as a chain of amino acid residues that are either hydrophobic or polar, and hydrophobic interactions are the dominant initial driving force for the protein folding. Hart and Istrail (1996a) gave approximation algorithms for folding proteins on the cubic lattice under the HP model. In this paper, we examine the choice of a lattice by considering its algorithmic and geometric implications and argue that the triangular lattice is a more reasonable choice. We present a set of folding rules for a triangular lattice and analyze the approximation ratio they achieve. In addition, we introduce a generalization of the HP model to account for residues having different levels of hydrophobicity. After describing the biological foundation for this generalization, we show that in the new model we are able to achieve similar constant factor approximation guarantees on the triangular lattice as were achieved in the standard HP model. While the structures derived from our folding rules are probably still far from biological reality, we hope that having a set of folding rules with different properties will yield more interesting folds when combined. VL - 4 SN - 1066-5277, 1557-8666 UR - http://www.liebertonline.com/doi/abs/10.1089/cmb.1997.4.275 CP - 3 M3 - 10.1089/cmb.1997.4.275 ER - TY - JOUR T1 - Optimized software synthesis for synchronous dataflow JF - Proceedings of the ASAP97 Y1 - 1997 A1 - Bhattacharyya, Shuvra S. A1 - America,H. ER - TY - CHAP T1 - Regulation of Cable Television T2 - The Froehlich/Kent Encyclopedia of Telecommunications: Volume 15-Radio Astronomy to Submarine Cable SystemsThe Froehlich/Kent Encyclopedia of Telecommunications: Volume 15-Radio Astronomy to Submarine Cable Systems Y1 - 1997 A1 - Agrawala, Ashok K. A1 - CILINGIROGLU,A. A1 - Lee,S. JA - The Froehlich/Kent Encyclopedia of Telecommunications: Volume 15-Radio Astronomy to Submarine Cable SystemsThe Froehlich/Kent Encyclopedia of Telecommunications: Volume 15-Radio Astronomy to Submarine Cable Systems VL - 15 ER - TY - JOUR T1 - Run-time and compiler support for programming in adaptive parallel environments JF - Scientific Programming Y1 - 1997 A1 - Edjlali,G. A1 - Agrawal,G. A1 - Sussman, Alan A1 - Humphries,J. A1 - Saltz, J. VL - 6 CP - 2 ER - TY - CONF T1 - A secure and reliable bootstrap architecture T2 - , 1997 IEEE Symposium on Security and Privacy, 1997. Proceedings Y1 - 1997 A1 - Arbaugh, William A. A1 - Farber,D. J A1 - Smith,J. M KW - active networks KW - AEGIS architecture KW - bootstrap architecture KW - Computer architecture KW - computer bootstrapping KW - data integrity KW - Distributed computing KW - Hardware KW - hardware validity KW - initialization KW - integrity chain KW - integrity check failures KW - Internet KW - Internet commerce KW - IP networks KW - Laboratories KW - lower-layer integrity KW - Microprogramming KW - Operating systems KW - recovery process KW - reliability KW - robust systems KW - Robustness KW - Security KW - security of data KW - software reliability KW - system integrity guarantees KW - system recovery KW - transitions KW - Virtual machining AB - In a computer system, the integrity of lower layers is typically treated as axiomatic by higher layers. Under the presumption that the hardware comprising the machine (the lowest layer) is valid, the integrity of a layer can be guaranteed if and only if: (1) the integrity of the lower layers is checked and (2) transitions to higher layers occur only after integrity checks on them are complete. The resulting integrity “chain” inductively guarantees system integrity. When these conditions are not met, as they typically are not in the bootstrapping (initialization) of a computer system, no integrity guarantees can be made, yet these guarantees are increasingly important to diverse applications such as Internet commerce, security systems and “active networks”. In this paper, we describe the AEGIS architecture for initializing a computer system. It validates integrity at each layer transition in the bootstrap process. AEGIS also includes a recovery process for integrity check failures, and we show how this results in robust systems JA - , 1997 IEEE Symposium on Security and Privacy, 1997. Proceedings PB - IEEE SN - 0-8186-7828-3 M3 - 10.1109/SECPRI.1997.601317 ER - TY - JOUR T1 - Testing simple polygons JF - Computational Geometry Y1 - 1997 A1 - Arkin,Esther M. A1 - Belleville,Patrice A1 - Mitchell,Joseph S.B. A1 - Mount, Dave A1 - Romanik,Kathleen A1 - Salzberg,Steven A1 - Souvaine,Diane KW - probing KW - Testing KW - Verifying AB - We consider the problem of verifying a simple polygon in the plane using “test points”. A test point is a geometric probe that takes as input a point in Euclidean space, and returns “+” if the point is inside the object being probed or “−” if it is outside. A verification procedure takes as input a description of a target object, including its location and orientation, and it produces a set of test points that are used to verify whether a test object matches the description. We give a procedure for verifying an n-sided, non-degenerate, simple target polygon using 5n test points. This testing strategy works even if the test polygon has n + 1 vertices, and we show a lower bound of 3n + 1 test points for this case. We also give algorithms using O(n) test points for simple polygons that may be degenerate and for test polygons that may have up to n + 2 vertices. All of these algorithms work for polygons with holes. We also discuss extensions of our results to higher dimensions. VL - 8 SN - 0925-7721 UR - http://www.sciencedirect.com/science/article/pii/S0925772196000156 CP - 2 M3 - 10.1016/S0925-7721(96)00015-6 ER - TY - CONF T1 - Titan: a High-Performance Remote-sensing Database T2 - In Proceedings of the 1997 International Conference on Data Engineering Y1 - 1997 A1 - Bongki,C. C A1 - Chang,C. A1 - Moon,B. A1 - Acharya, A. A1 - Shock,C. A1 - Sussman, Alan A1 - Saltz, J. JA - In Proceedings of the 1997 International Conference on Data Engineering ER - TY - CHAP T1 - Toward motion picture grammars T2 - Computer Vision — ACCV'98Computer Vision — ACCV'98 Y1 - 1997 A1 - Bolle,Ruud A1 - Aloimonos, J. A1 - Fermüller, Cornelia ED - Chin,Roland ED - Pong,Ting-Chuen AB - We are interested in processing video data for the purpose of solving a variety of problems in video search, analysis, indexing, browsing and compression. Instead of concentrating on a particular problem, in this paper we present a framework for developing video applications. Our basic thesis is that video data can be represented at a higher level of abstraction as a string generated by a grammar, termed motion picture grammar. The rules of that grammar relate different spatiotemporal representations of the video content and, in particular, representations of action. JA - Computer Vision — ACCV'98Computer Vision — ACCV'98 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1352 SN - 978-3-540-63931-2 UR - http://dx.doi.org/10.1007/3-540-63931-4_228 ER - TY - JOUR T1 - Visual Navigation: Flies, Bees, and UGV's JF - Visual navigation: from biological systems to unmanned ground vehicles Y1 - 1997 A1 - Aloimonos, J. ER - TY - BOOK T1 - Visual navigation: from biological systems to unmanned ground vehicles Y1 - 1997 A1 - Aloimonos, J. PB - Lawrence Erlbaum ER - TY - JOUR T1 - Visual space distortion JF - Biological Cybernetics Y1 - 1997 A1 - Fermüller, Cornelia A1 - LoongFah Cheong A1 - Aloimonos, J. AB - We are surrounded by surfaces that we perceive by visual means. Understanding the basic principles behind this perceptual process is a central theme in visual psychology, psychophysics, and computational vision. In many of the computational models employed in the past, it has been assumed that a metric representation of physical space can be derived by visual means. Psychophysical experiments, as well as computational considerations, can convince us that the perception of space and shape has a much more complicated nature, and that only a distorted version of actual, physical space can be computed. This paper develops a computational geometric model that explains why such distortion might take place. The basic idea is that, both in stereo and motion, we perceive the world from multiple views. Given the rigid transformation between the views and the properties of the image correspondence, the depth of the scene can be obtained. Even a slight error in the rigid transformation parameters causes distortion of the computed depth of the scene. The unified framework introduced here describes this distortion in computational terms. We characterize the space of distortions by its level sets, that is, we characterize the systematic distortion via a family of iso-distortion surfaces which describes the locus over which depths are distorted by some multiplicative factor. Given that humans' estimation of egomotion or estimation of the extrinsic parameters of the stereo apparatus is likely to be imprecise, the framework is used to explain a number of psychophysical experiments on the perception of depth from motion or stereo. VL - 77 SN - 0340-1200 UR - http://dx.doi.org/10.1007/s004220050393 CP - 5 ER - TY - JOUR T1 - Accounting for boundary effects in nearest-neighbor searching JF - Discrete & Computational Geometry Y1 - 1996 A1 - Arya,S. A1 - Mount, Dave A1 - Narayan,O. AB - Given n data points ind-dimensional space, nearest-neighbor searching involves determining the nearest of these data points to a given query point. Most averagecase analyses of nearest-neighbor searching algorithms are made under the simplifying assumption thatd is fixed and thatn is so large relative tod thatboundary effects can be ignored. This means that for any query point the statistical distribution of the data points surrounding it is independent of the location of the query point. However, in many applications of nearest-neighbor searching (such as data compression by vector quantization) this assumption is not met, since the number of data pointsn grows roughly as 2 d .Largely for this reason, the actual performances of many nearest-neighbor algorithms tend to be much better than their theoretical analyses would suggest. We present evidence of why this is the case. We provide an accurate analysis of the number of cells visited in nearest-neighbor searching by the bucketing andk-d tree algorithms. We assumem dpoints uniformly distributed in dimensiond, wherem is a fixed integer ≥2. Further, we assume that distances are measured in theL ∞ metric. Our analysis is tight in the limit asd approaches infinity. Empirical evidence is presented showing that the analysis applies even in low dimensions. VL - 16 CP - 2 M3 - 10.1007/BF02716805 ER - TY - CHAP T1 - Conjugate Gradients and Related KMP Algorithms: The Beginnings T2 - Linear and Nonlinear Conjugate Gradient-Related MethodsLinear and Nonlinear Conjugate Gradient-Related Methods Y1 - 1996 A1 - O'Leary, Dianne P. ED - Adams,Loyce ED - Nazareth,J. L. JA - Linear and Nonlinear Conjugate Gradient-Related MethodsLinear and Nonlinear Conjugate Gradient-Related Methods PB - SIAM CY - Philadelphia ER - TY - CHAP T1 - Directions of motion fields are hardly ever ambiguous T2 - Computer Vision — ECCV '96Computer Vision — ECCV '96 Y1 - 1996 A1 - Brodsky, Tomas A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Buxton,Bernard ED - Cipolla,Roberto AB - Recent literature [7, 10, 11, 9, 13, 17] provides a number of results regarding uniqueness aspects of motion fields and exact image displacements due to 3-D rigid motion. Here instead of the full motion field we consider only the direction of the motion field due to a rigid motion and ask what can we say about the three-dimensional motion information contained in it. This paper provides a geometric analysis of this question based solely on the fact that the depth of the surfaces in view is positive (i.e. that the surface in view is in front of the camera). With this analysis we thus offer a theoretical foundation for image constraints employing only the sign of flow in various directions and provide a solid basis for their utilization in addressing 3D dynamic vision problems. JA - Computer Vision — ECCV '96Computer Vision — ECCV '96 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1065 SN - 978-3-540-61123-3 UR - http://dx.doi.org/10.1007/3-540-61123-1_132 ER - TY - JOUR T1 - Early detection of independent motion from active control of normal image flow patterns JF - Systems, Man, and Cybernetics, Part B: Cybernetics, IEEE Transactions on Y1 - 1996 A1 - Sharma, R. A1 - Aloimonos, J. VL - 26 CP - 1 ER - TY - CONF T1 - Effect of chemical reactions on the decay of isotropic homogeneous turbulence T2 - AIAA Fluid Dynamics Conference Y1 - 1996 A1 - Aguirre,M A1 - Candler,G. V A1 - Martin, M.P AB - Direct numerical simulations, (DNS), are usedto simulate the decay of an isotopic, turbulent, chemically-reacting flow at high temperatures. The independent parameters that govern the physical pro- cess are introduced. The different effects from each of the parameters in the flow are explained by using the results from the DNS. It is found that there is a feedback mechanism between the chemical reactions and the turbulent motion. This feedback is positive for exothermic reactions and negative for endother- mic reactions. JA - AIAA Fluid Dynamics Conference CY - New Orleans, LA VL - 96 ER - TY - RPRT T1 - Estimation of time-dependent coverage Y1 - 1996 A1 - Arlat,D. P. M. C. J. A1 - Crouzet,Y. AB - It is well-known that the dependability that can be achieved by a fault-tolerant systemis particularly sensitive to both the asymptotic value of coverage and to the time distribution of coverage. However, most previous work on coverage evaluation by statistical processing of the results of fault-injection experiments has only been concerned with estimating asymptotic coverage. In this paper, we tackle the problem of estimating the parameters of models that also account for coverage latency. After discussing some data sets resulting from fault-injection experiments on practical systems, we propose a series of coverage latency models that might be considered to account for the observed phenomena in a system dependability evaluation. We consider both exponential and non-exponential models, and assess their pertinence by means of a sensitivity study. We confirm previous results that latency can have an extremely important effect on the achievable dependability. We also show that the shape of the latency distribution has only a minor impact in the practical case of systems with high asymptotic coverage. A simple action model based on an exponential latency distribution is therefore proposed. We show how worst-case confidence limits can be obtained for the parameters of this action model and study the effects of data truncation that are unavoidable in any practical measurements of latency. We conclude by a critical assessment of the proposed estimation technique and a demonstration of its application to practical data sets. PB - LAAS-CNRS: Laboratory for analysis and architecture of systems CY - Toulouse, France VL - 96466 UR - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.48.8253&rep=rep1&type=pdf ER - TY - BOOK T1 - Interaction between 3D Shape and Motion: Theory and Applications Y1 - 1996 A1 - Fermüller, Cornelia A1 - Aloimonos, J. A1 - Cheong,L. AB - Research during the past few years has attempted to characterize the errors that arise in computing 3D motion (egomotion estimation) and in a scene's structure (structure from motion) from a sequence of images acquired by a moving sensor. This paper presents a new geometric framework that characterizes how the three-dimensional space recovered by a moving monocular observer, whose 3D motion is estimated with some error, is distorted. We characterize the space of distortions by its level sets, that is, by a family of iso-distortion surfaces, each of which describes the locus over which the depths of points in the scene are distorted by the same multiplicative factor. By analyzing the geometry of the regions where the distortion factor is negative, that is, where the visibility constraint is violated, we make explicit situations which are likely to give rise to ambiguities in motion estimation. We also apply our approach to a uniqueness analysis for 3D motion analysis from normal flow; we study the constraints on egomotion, object motion and depth for an independently moving object to be detectable by a moving observer; and we offer a quantitative account of the precision needed in an inertial sensor for accurate estimation of 3D motion. PB - Computer Vision Laboratory, University of Maryland ER - TY - RPRT T1 - MARUTI at ARDEC. Y1 - 1996 A1 - Agrawala, Ashok K. A1 - Tripathi,Satish K KW - *OPERATING SYSTEMS(COMPUTERS) KW - Computer architecture KW - COMPUTER PROGRAMMING AND SOFTWARE KW - CONTROL KW - Cooperation KW - DSSA(DOMAIN SPECIFIC SOFTWARE ARCHITECTURE) KW - GUN TURRETS. KW - HIGH FREQUENCY KW - Laboratories KW - REAL TIME KW - ROBOTICS KW - TEST BEDS AB - This is the final report of the effort undertaken at the University of Maryland, sponsored by DARPA under the DSSA (Domain Specific Software Architectures) program. The activities reported here required an active cooperation and collaboration of the US Army ARDEC (Automation and Robotics Laboratory) and the University of Maryland (Computer Science Department). The principal investigators have been developing a hard real time operating system, MARUTI, at the University of Maryland. The goal of this effort was to demonstrate the applicability and usefulness of this operating system for exercising PID control at high frequency on the ATB1000 testbed which has been used to simulate a gun turret. A MARUTI based PID controller which operates at 200 HZ and 400 HZ was successfully implemented to demonstrate this feasibility. PB - University of Maryland, College Park UR - http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA315086 ER - TY - JOUR T1 - An on-line variable-length binary encoding of text JF - Information Sciences Y1 - 1996 A1 - Acharya,Tinku A1 - JaJa, Joseph F. AB - We present a methodology for on-line variable-length binary encoding of a dynamically growing set of integers. Our encoding maintains the prefix property that enables unique decoding of a string of integers from the set. In order to develop the formalism of this on-line binary encoding, we define a unique binary tree data structure called the “phase in binary tree.” To show the utility of this on-line variable-length binary encoding, we apply this methodology to encode the pointers generated by the LZW algorithm. The experimental results obtained illustrate the superior performance of our algorithm compared to the most widely used algorithms. This on-line variable-length binary encoding can be applied in other dictionary-based text compression schemes as well to effectively encode the output pointers to enhance the compression ratio. VL - 94 SN - 0020-0255 UR - http://www.sciencedirect.com/science/article/pii/0020025596000898 CP - 1–4 M3 - 10.1016/0020-0255(96)00089-8 ER - TY - JOUR T1 - Ordinal representations of visual space JF - Proc. Image Understanding Workshop Y1 - 1996 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ER - TY - CONF T1 - Runtime coupling of data-parallel programs T2 - Proceedings of the 10th international conference on Supercomputing Y1 - 1996 A1 - Ranganathan,M. A1 - Acharya, A. A1 - Edjlali,G. A1 - Sussman, Alan A1 - Saltz, J. JA - Proceedings of the 10th international conference on Supercomputing ER - TY - CONF T1 - Simplification envelopes T2 - Proceedings of the 23rd annual conference on Computer graphics and interactive techniques Y1 - 1996 A1 - Cohen,Jonathan A1 - Varshney, Amitabh A1 - Manocha,Dinesh A1 - Turk,Greg A1 - Weber,Hans A1 - Agarwal,Pankaj A1 - Brooks,Frederick A1 - Wright,William KW - geometric modeling KW - hierarchical approximation KW - levels-of-detail generation KW - model simplification KW - offsets KW - shape approximation JA - Proceedings of the 23rd annual conference on Computer graphics and interactive techniques T3 - SIGGRAPH '96 PB - ACM CY - New York, NY, USA SN - 0-89791-746-4 UR - http://doi.acm.org/10.1145/237170.237220 M3 - 10.1145/237170.237220 ER - TY - CHAP T1 - Spatiotemporal representations for visual navigation T2 - Computer Vision — ECCV '96Computer Vision — ECCV '96 Y1 - 1996 A1 - LoongFah Cheong A1 - Fermüller, Cornelia A1 - Aloimonos, J. ED - Buxton,Bernard ED - Cipolla,Roberto AB - The study of visual navigation problems requires the integration of visual processes with motor control. Most essential in approaching this integration is the study of appropriate spatio-temporal representations which the system computes from the imagery and which serve as interfaces to all motor activities. Since representations resulting from exact quantitative reconstruction have turned out to be very hard to obtain, we argue here for the necessity of representations which can be computed easily, reliably and in real time and which recover only the information about the 3D world which is really needed in order to solve the navigational problems at hand. In this paper we introduce a number of such representations capturing aspects of 3D motion and scene structure which are used for the solution of navigational problems implemented in visual servo systems. In particular, the following three problems are addressed: (a) to change the robot's direction of motion towards a fixed direction, (b) to pursue a moving target while keeping a certain distance from the target, and (c) to follow a wall-like perimeter. The importance of the introduced representations lies in the following: – They can be extracted using minimal visual information, in particular the sign of flow measurements or the the first order spatiotemporal derivatives of the image intensity function. In that sense they are direct representations needing no intermediate level of computation such as correspondence. – They are global in the sense that they represent how three-dimensional information is globally encoded in them. Thus, they are robust representations since local errors do not affect them. – Usually, from sequences of images, three-dimensional quantities such as motion and shape are computed and used as input to control processes. The representations discussed here are given directly as input to the control procedures, thus resulting in a real time solution. JA - Computer Vision — ECCV '96Computer Vision — ECCV '96 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1064 SN - 978-3-540-61122-6 UR - http://dx.doi.org/10.1007/BFb0015577 ER - TY - CHAP T1 - On stratified sampling for high coverage estimations T2 - Dependable Computing — EDCC-2 Y1 - 1996 A1 - Powell,David A1 - Cukier, Michel A1 - Arlat,Jean ED - Hlawiczka,Andrzej ED - Silva,João ED - Simoncini,Luca KW - Computer science AB - This paper addresses the problem of estimating the coverage of a fault tolerance mechanism through statistical processing of observations collected in faultinjection experiments. In an earlier paper, several techniques for sampling the fault/activity input space of a fault tolerance mechanism were presented. Various estimators based on simple sampling in the whole space and stratified sampling in a partitioned space were studied; confidence limits were derived based on a normal approximation. In this paper, the validity of this approximation is analyzed, especially for high coverage systems. The theory of confidence regions is then introduced to estimate the coverage without approximation when, for practical reasons, stratification is used. Three statistics are considered for defining confidence regions. It is shown that one of these statistics — a vectorial statistic — is often more conservative than the other two. However, only the vectorial statistic is computationally tractable. The results obtained are compared with those based on approximation by means of three hypothetical example systems. JA - Dependable Computing — EDCC-2 T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1150 SN - 978-3-540-61772-3 UR - http://www.springerlink.com/content/7t2w2u472601h730/abstract/ ER - TY - JOUR T1 - The synthesis of vision and action JF - Exploratory vision: the active eye Y1 - 1996 A1 - Fermüller, Cornelia A1 - Aloimonos, J. ER - TY - CONF T1 - Tuning the performance of I/O-intensive parallel applications T2 - Proceedings of the fourth workshop on I/O in parallel and distributed systems: part of the federated computing research conference Y1 - 1996 A1 - Acharya, A. A1 - Uysal, M. A1 - Bennett, R. A1 - Mendelson, A. A1 - Beynon, M. A1 - Hollingsworth, Jeffrey K A1 - Saltz, J. A1 - Sussman, Alan JA - Proceedings of the fourth workshop on I/O in parallel and distributed systems: part of the federated computing research conference ER - TY - CHAP T1 - Video representations T2 - Recent Developments in Computer Vision Y1 - 1996 A1 - Bolle,Ruud A1 - Aloimonos, J. A1 - Fermüller, Cornelia ED - Li,Stan ED - Mital,Dinesh ED - Teoh,Eam ED - Wang,Han JA - Recent Developments in Computer Vision T3 - Lecture Notes in Computer Science PB - Springer Berlin / Heidelberg VL - 1035 SN - 978-3-540-60793-9 UR - http://dx.doi.org/10.1007/3-540-60793-5_60 ER - TY - CONF T1 - Where is information visualization technology going? T2 - Proceedings of the 9th annual ACM symposium on User interface software and technology Y1 - 1996 A1 - Hascoët-Zizi,Mountaz A1 - Ahlberg,Chris A1 - Korfhage,Robert A1 - Plaisant, Catherine A1 - Chalmers,Matthew A1 - Rao,Ramana JA - Proceedings of the 9th annual ACM symposium on User interface software and technology T3 - UIST '96 PB - ACM CY - New York, NY, USA SN - 0-89791-798-7 UR - http://doi.acm.org/10.1145/237091.237101 M3 - 10.1145/237091.237101 ER - TY - CONF T1 - 3D motion representations in visual servo control T2 - Proceedings of International Symposium on Computer Vision, 1995 Y1 - 1995 A1 - Fermüller, Cornelia A1 - LoongFah Cheong A1 - Aloimonos, J. KW - 3D motion representations KW - autonomous behavior KW - CAMERAS KW - computational effort KW - Computer vision KW - dynamic imagery KW - global spatiotemporal representations KW - image representation KW - Mobile robots KW - motion control KW - Navigation KW - navigational problems KW - Optical computing KW - Robot kinematics KW - Robot sensing systems KW - robot vision KW - Robot vision systems KW - Robotics and automation KW - servomechanisms KW - Servosystems KW - Spatiotemporal phenomena KW - vision-guided robotics KW - visual information KW - visual servo control KW - visual servoing AB - A new approach to visual servoing and vision-guided robotics is introduced. This approach uses visual information for autonomous behavior. It amounts to using robust, global spatiotemporal representations easily extracted from the dynamic imagery. Specifically, the geometrical patterns of normal flows are used as the input to the servo mechanism. It is shown that the positions of these patterns are related to the three dimensional motion parameters. By locating the positions of these patterns, we can solve a variety of navigational problems with little computational effort JA - Proceedings of International Symposium on Computer Vision, 1995 PB - IEEE SN - 0-8186-7190-4 M3 - 10.1109/ISCV.1995.476978 ER - TY - CONF T1 - Approximate range searching T2 - Proceedings of the eleventh annual symposium on Computational geometry Y1 - 1995 A1 - Arya,Sunil A1 - Mount, Dave JA - Proceedings of the eleventh annual symposium on Computational geometry T3 - SCG '95 PB - ACM CY - New York, NY, USA SN - 0-89791-724-3 UR - http://doi.acm.org/10.1145/220279.220298 M3 - 10.1145/220279.220298 ER - TY - BOOK T1 - Artificial Intelligence: Theory and Practice Y1 - 1995 A1 - Dean, Thomas L. A1 - ALLEN, JAMES AUTOR A1 - Aloimonos, J. KW - Computers / Expert Systems KW - Computers / Intelligence (AI) & Semantics AB - This book provides a detailed understanding of the broad issues in artificial intelligence and a useful survey of current AI technology. The author delivers broad coverage of innovative representational techniques, including neural networks, image processing, and probabilistic reasoning, alongside the traditional methods of symbolic reasoning. AI algorithms are described in detailed prose in the text and fully implemented in LISP at the ends of chapters. A stand-alone LISP chapter makes an excellent reference and refresher. Each chapter includes a detailed description of an AI application. PB - Benjamin/Cummings Pub. SN - 9780805325478 ER - TY - JOUR T1 - Automatic generation of multiresolution for polygonal models JF - First Workshop on Simulation and Interaction in Virtual Environments Y1 - 1995 A1 - Varshney, Amitabh A1 - Agarwal,P. A1 - Brooks,F. A1 - Wright,W. A1 - Weber,H. ER - TY - JOUR T1 - cDNA expressed sequence tags of Trypanosoma brucei rhodesiense provide new insights into the biology of the parasite JF - Molecular and Biochemical Parasitology Y1 - 1995 A1 - El‐Sayed, Najib M. A1 - Alarcon,Clara M. A1 - Beck,John C. A1 - Sheffield,Val C. A1 - Donelson,John E. KW - cDNA KW - Expressed sequence tag KW - Trypanosoma brucei rhodesiense AB - A total of 518 expressed sequence tags (ESTs) have been generated from clones randomly selected from a cDNA library and a spliced leader sub-library of a Trypanosoma brucei rhodesiense bloodstream clone. 205 (39%) of the clones were identified based on matches to 113 unique genes in the public databases. Of these, 71 cDNAs display significant similarities to genes in unrelated organisms encoding metabolic enzymes, signal transduction proteins, transcription factors, ribosomal proteins, histones, a proliferation-associated protein and thimet oligopeptidase, among others. 313 of the cDNAs are not related to any other sequences in the databases. These cDNA ESTs provide new avenues of research for exploring both the novel trypanosome-specific genes and the genome organization of this parasite, as well as a resource for identifying trypanosome homologs to genes expressed in other organisms. VL - 73 SN - 0166-6851 UR - http://www.sciencedirect.com/science/article/pii/016668519500098L CP - 1-2 M3 - 16/0166-6851(95)00098-L ER - TY - JOUR T1 - Crystallization and preliminary X-ray investigation of the recombinant Trypanosoma brucei rhodesiense calmodulin JF - Proteins: Structure, Function, and Bioinformatics Y1 - 1995 A1 - El‐Sayed, Najib M. A1 - Patton,C. L A1 - Harkins,P. C A1 - Fox,R. O A1 - Anderson,K. VL - 21 CP - 4 ER - TY - CONF T1 - Data parallel programming in an adaptive environment T2 - Parallel Processing Symposium, 1995. Proceedings., 9th International Y1 - 1995 A1 - Edjlali,G. A1 - Agrawal,G. A1 - Sussman, Alan A1 - Saltz, J. JA - Parallel Processing Symposium, 1995. Proceedings., 9th International ER - TY - JOUR T1 - Direct Perception of Three-Dimensional Motion from Patterns of Visual Motion JF - ScienceScience Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - Measurements of retinal motion along a set of predetermined orientations on the retina of a moving system give rise to global patterns. Because the form and location of these patterns depend purely on three-dimensional (3D) motion, the effects of 3D motion and scene structure on image motion can be globally separated. The patterns are founded on easily derivable image measurements that depend only on the sign of image motion and do not require information about optical flow. The computational theory presented here explains how the self-motion of a system can be estimated by locating these patterns. VL - 270 SN - 0036-8075, 1095-9203 UR - http://www.sciencemag.org/content/270/5244/1973 CP - 5244 M3 - 10.1126/science.270.5244.1973 ER - TY - RPRT T1 - Enhancing LZW Coding Using a Variable-Length Binary Encoding Y1 - 1995 A1 - Acharya,Tinku A1 - JaJa, Joseph F. KW - algorithms KW - data compression KW - Systems Integration Methodology AB - We present here a methodology to enhance the LZW coding for text compression using a variable-length binary encoding scheme. The basic principle of this encoding is based on allocating a set of prefix codes to a set of integers growing dynamically. The prefix property enables unique decoding of a string of elements from this set. We presented the experimental results to show the effectiveness of this variable-length binary encoding scheme. PB - Institute for Systems Research, University of Maryland, College Park VL - ISR-TR-1995-70 UR - http://drum.lib.umd.edu/handle/1903/5654 ER - TY - CONF T1 - Euclidean spanners: short, thin, and lanky T2 - Proceedings of the twenty-seventh annual ACM symposium on Theory of computing Y1 - 1995 A1 - Arya,Sunil A1 - Das,Gautam A1 - Mount, Dave A1 - Salowe,Jeffrey S. A1 - Smid,Michiel JA - Proceedings of the twenty-seventh annual ACM symposium on Theory of computing T3 - STOC '95 PB - ACM CY - New York, NY, USA SN - 0-89791-718-9 UR - http://doi.acm.org/10.1145/225058.225191 M3 - 10.1145/225058.225191 ER - TY - RPRT T1 - Generating levels of detail for large-scale polygonal models Y1 - 1995 A1 - Varshney, Amitabh A1 - Agarwal,P. K A1 - Brooks Jr,F. P A1 - Wright,W. V A1 - Weber,H. AB - We present an e cient algorithm for generating various levels-of-detail approximations for agiven polygonal model. Our algorithm guarantees that all points of an approximation are within a user-speci able distance from the original model and all points of the original model are within a distance from the approximation. Each approximation attempts to minimize the total number of polygons required to satisfy the previous constraint. We show how the problem of generating levels- of-detail approximations reduces to the classic set partition problem. The various approximations are guaranteed to be topologically consistent with the input polygonal model. The approximations can be constrained by the user to preserve any desired edges of the input model. We also propose a method to compute an estimate of the quality of the approximation generated by our algorithm with respect to the optimal approximation satisfying the same constraints. We have implemented our algorithm and have obtained experimental results of multiresolution hierarchy generation on over a thousand polygonal objects from a CAD model of a notional submarine. PB - Department of Computer Science, Duke University, North Carolina VL - CS-1995-20 ER - TY - CONF T1 - Global rigidity constraints in image displacement fields T2 - Proceedings of Fifth International Conference on Computer Vision, 1995 Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion parameters KW - algorithms KW - Automation KW - Computer science KW - Computer vision KW - conic sections KW - curves KW - equal vectors KW - Fluid flow measurement KW - global geometric structure KW - global rigidity constraints KW - image displacement fields KW - Image motion analysis KW - Image segmentation KW - Image sequences KW - imaging surface KW - Laboratories KW - Layout KW - Motion estimation KW - Motion measurement KW - motion vectors KW - multiple views KW - normal flow fields KW - optical flow fields KW - regions KW - rigid motion KW - stereo disparity fields KW - Stereo vision KW - vectors KW - visual information recovery AB - Image displacement fields-optical flow fields, stereo disparity fields, normal flow fields-due to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constrained to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The goal of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views JA - Proceedings of Fifth International Conference on Computer Vision, 1995 PB - IEEE SN - 0-8186-7042-8 M3 - 10.1109/ICCV.1995.466779 ER - TY - CONF T1 - Global rigidity constraints in image displacement fields T2 - , Fifth International Conference on Computer Vision, 1995. Proceedings Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - 3D motion parameters KW - algorithms KW - Automation KW - Computer science KW - Computer vision KW - conic sections KW - curves KW - equal vectors KW - Fluid flow measurement KW - global geometric structure KW - global rigidity constraints KW - image displacement fields KW - Image motion analysis KW - Image segmentation KW - Image sequences KW - imaging surface KW - Laboratories KW - Layout KW - Motion estimation KW - Motion measurement KW - motion vectors KW - multiple views KW - normal flow fields KW - optical flow fields KW - regions KW - rigid motion KW - stereo disparity fields KW - Stereo vision KW - vectors KW - visual information recovery AB - Image displacement fields-optical flow fields, stereo disparity fields, normal flow fields-due to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constrained to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The goal of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views JA - , Fifth International Conference on Computer Vision, 1995. Proceedings PB - IEEE SN - 0-8186-7042-8 M3 - 10.1109/ICCV.1995.466779 ER - TY - CONF T1 - The information in the direction of image flow T2 - , International Symposium on Computer Vision, 1995. Proceedings Y1 - 1995 A1 - Brodsky, T. A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - Automation KW - CAMERAS KW - Computer vision KW - Educational institutions KW - image flow KW - Image motion analysis KW - Image sequences KW - imaging surface KW - Laboratories KW - Layout KW - Motion analysis KW - Motion estimation KW - motion field KW - motion vectors KW - Optical imaging KW - rigid motion KW - rigid motions KW - three-dimensional motion AB - If instead of the full motion field, we consider only the direction of the motion field due to a rigid motion, what can we say about the information regarding the three-dimensional motion? In this paper it is shown that considering as the imaging surface the whole sphere, independently of the scene in view, two different rigid motions cannot give rise to the same directional motion field. If we restrict the image to half of a sphere (or an infinitely large image plane) two different rigid motions with instantaneous translational and rotational velocities (t1, ω1) and (t2, ω2) cannot give rise to the same directional motion field unless the plane through t1 and t2 is perpendicular to the plane through ω1 and ω2 (i.e., (t1×t2)·(ω1 ×ω2)=0). In addition, in order to give a practical significance to these uniqueness results for the case of a limited field of view we also characterize the locations on the image where the motion vectors due to the different motions must have different directions. If (ω1×ω2)·(t1 ×t2)=0 and certain additional constraints are met, then the two rigid motions could produce motion fields with the same direction. For this to happen the depth of each corresponding surface has to be within a certain range, defined by a second and a third order surface JA - , International Symposium on Computer Vision, 1995. Proceedings PB - IEEE SN - 0-8186-7190-4 M3 - 10.1109/ISCV.1995.477071 ER - TY - JOUR T1 - An integrated runtime and compile-time approach for parallelizing structured and block structured applications JF - IEEE Transactions on Parallel and Distributed Systems Y1 - 1995 A1 - Agrawal,G. A1 - Sussman, Alan A1 - Saltz, J. KW - Bandwidth KW - block structured applications KW - block structured codes KW - compile-time approach KW - compiling applications KW - data access patterns KW - Data analysis KW - Delay KW - distributed memory machines KW - distributed memory systems KW - FORTRAN KW - Fortran 90D/HPF compiler KW - High performance computing KW - HPF-like parallel programming languages KW - integrated runtime approach KW - irregularly coupled regular mesh problems KW - multigrid code KW - Navier-Stokes solver template KW - Parallel machines KW - parallel programming KW - Pattern analysis KW - performance evaluation KW - program compilers KW - Program processors KW - Runtime library KW - Uninterruptible power systems AB - In compiling applications for distributed memory machines, runtime analysis is required when data to be communicated cannot be determined at compile-time. One such class of applications requiring runtime analysis is block structured codes. These codes employ multiple structured meshes, which may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). In this paper, we present runtime and compile-time analysis for compiling such applications on distributed memory parallel machines in an efficient and machine-independent fashion. We have designed and implemented a runtime library which supports the runtime analysis required. The library is currently implemented on several different systems. We have also developed compiler analysis for determining data access patterns at compile time and inserting calls to the appropriate runtime routines. Our methods can be used by compilers for HPF-like parallel programming languages in compiling codes in which data distribution, loop bounds and/or strides are unknown at compile-time. To demonstrate the efficacy of our approach, we have implemented our compiler analysis in the Fortran 90D/HPF compiler developed at Syracuse University. We have experimented with a multi-bloc Navier-Stokes solver template and a multigrid code. Our experimental results show that our primitives have low runtime communication overheads and the compiler parallelized codes perform within 20% of the codes parallelized by manually inserting calls to the runtime library VL - 6 SN - 1045-9219 CP - 7 M3 - 10.1109/71.395403 ER - TY - CONF T1 - Iso-distortion contours and egomotion estimation T2 - Proceedings of International Symposium on Computer Vision, 1995 Y1 - 1995 A1 - LoongFah Cheong A1 - Aloimonos, J. KW - Automation KW - Computer vision KW - Degradation KW - depth distortion KW - Educational institutions KW - egomotion estimation KW - Equations KW - erroneous motion estimates KW - Error analysis KW - HUMANS KW - Image sequences KW - iso-distortion contours KW - Laboratories KW - Layout KW - Motion estimation KW - Robustness KW - visibility constraint AB - This paper introduces the framework of iso-distortion contour to deal with the problem of depth distortion due to erroneous motion estimates, and various related aspects such as the effectiveness of the visibility constraint. The framework can also be used to inquire the uniqueness aspect of normal flow. Future work will examine the implications of the iso-distortion contours for the problem of multiple frame integration JA - Proceedings of International Symposium on Computer Vision, 1995 PB - IEEE SN - 0-8186-7190-4 M3 - 10.1109/ISCV.1995.476977 ER - TY - CONF T1 - M.H.M: Euclidean spanners: short, thin, and lanky T2 - In: 27th ACM Symposium on Theory of Computing Y1 - 1995 A1 - Arya,Sunil A1 - Dast,Gautam A1 - Mount, Dave A1 - Salowe,Jeffrey S. A1 - Smid,Michiel AB - Euclidean spanners are important data structures in geometric algorithm design, because they provide a means of approximating the complete Euclidean graph with only O(n) edges, so that the shortest path length between each pair of points is not more than a constant factor longer than the Euclidean distance between the points. In many applications of spanners, it is important that the spanner possess a number of additional properties: low tot al edge weight, bounded degree, and low diameter. Existing research on spanners has considered one property or the other. We show that it is possible to build spanners in optimal O (n log n) time and O(n) space that achieve optimal or near optimal tradeoffs between all combinations of these *Max-Planck-Institut fiir Informatik, D-66123 Saarbrucken, JA - In: 27th ACM Symposium on Theory of Computing PB - ACM press ER - TY - JOUR T1 - Next generation network management technology JF - AIP Conference Proceedings Y1 - 1995 A1 - Baras,John S A1 - Atallah,George C A1 - Ball,Mike A1 - Goli,Shravan A1 - Karne,Ramesh K A1 - Kelley,Steve A1 - Kumar,Harsha A1 - Plaisant, Catherine A1 - Roussopoulos, Nick A1 - Schneiderman,Ben A1 - Srinivasarao,Mulugu A1 - Stathatos,Kosta A1 - Teittinen,Marko A1 - Whitefield,David AB - Today’s telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be ‘‘mixed media’’ (copper, fiber‐optic, radio, and satellite); the subnetworks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be ‘‘multimedia’’ (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g., data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub‐networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object‐oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment. © 1995 American Institute of Physics VL - 325 SN - 0094243X UR - http://proceedings.aip.org/resource/2/apcpcs/325/1/75_1?isAuthorized=no CP - 1 M3 - doi:10.1063/1.47255 ER - TY - JOUR T1 - Qualitative egomotion JF - International Journal of Computer Vision Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. AB - Due to the aperture problem, the only motion measurement in images, whose computation does not require any assumptions about the scene in view, is normal flow—the projection of image motion on the gradient direction. In this paper we show how a monocular observer can estimate its 3D motion relative to the scene by using normal flow measurements in a global and qualitative way. The problem is addressed through a search technique. By checking constraints imposed by 3D motion parameters on the normal flow field, the possible space of solutions is gradually reduced. In the four modules that comprise the solution, constraints of increasing restriction are considered, culminating in testing every single normal flow value for its consistency with a set of motion parameters. The fact that motion is rigid defines geometric relations between certain values of the normal flow field. The selected values form patterns in the image plane that are dependent on only some of the motion parameters. These patterns, which are determined by the signs of the normal flow values, are searched for in order to find the axes of translation and rotation. The third rotational component is computed from normal flow vectors that are only due to rotational motion. Finally, by looking at the complete data set, all solutions that cannot give rise to the given normal flow field are discarded from the solution space. VL - 15 SN - 0920-5691 UR - http://dx.doi.org/10.1007/BF01450848 CP - 1 ER - TY - JOUR T1 - Qualitative vision JF - International Journal of Computer Vision Y1 - 1995 A1 - Aloimonos, J. VL - 14 CP - 2 ER - TY - CONF T1 - Representations for active vision T2 - Proceedings of the 14th international joint conference on Artificial intelligence - Volume 1 Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. JA - Proceedings of the 14th international joint conference on Artificial intelligence - Volume 1 PB - Morgan Kaufmann Publishers Inc. CY - San Francisco, CA, USA SN - 1-55860-363-8, 978-1-558-60363-9 UR - http://dl.acm.org/citation.cfm?id=1625855.1625858 ER - TY - JOUR T1 - Seeing and understanding: representing the visual world JF - ACM Comput. Surv. Y1 - 1995 A1 - Aloimonos, J. A1 - Fermüller, Cornelia A1 - Rosenfeld, A. VL - 27 SN - 0360-0300 UR - http://doi.acm.org/10.1145/212094.212101 CP - 3 M3 - 10.1145/212094.212101 ER - TY - JOUR T1 - Striving for correctness JF - Computers & Security Y1 - 1995 A1 - Abrams,Marshall D. A1 - Zelkowitz, Marvin V KW - Assurance KW - belief KW - correctness KW - Formal Methods KW - MATHEMATICAL MODELS KW - metrics KW - Process models KW - Risk management KW - Security testing KW - Silver bullets KW - simulation KW - Trustworthiness AB - In developing information technology, you want assurance that systems are secure and reliable, but you cannot have assurance or security without correctness. We discuss methods used to achieve correctness, focusing on weaknesses and approaches that management might take to increase belief in correctness. Formal methods, simulation, testing, and process modeling are addressed in detail. Structured programming, life-cycle modeling like the spiral model, use of CASE tools, use of formal methods, object-oriented design, reuse of existing code are also mentioned. Reliance on these methods involves some element of belief since no validated metrics on the effectiveness of these methods exist. Suggestions for using these methods as the basis for managerial decisions conclude the paper. VL - 14 SN - 0167-4048 UR - http://www.sciencedirect.com/science/article/pii/0167404895000224 CP - 8 M3 - 10.1016/0167-4048(95)00022-4 ER - TY - JOUR T1 - Using Treemaps to Visualize the Analytic Hierarchy Process JF - Information Systems ResearchInformation Systems Research Y1 - 1995 A1 - Asahi,Toshiyuki A1 - Turo,David A1 - Shneiderman, Ben KW - AHP KW - analytic hierarchy process KW - decision support KW - treemap KW - User interfaces KW - Visualization AB - Treemaps, a visualization method for large hierarchical data spaces, are used to augment the capabilities of the Analytic Hierarchy Process (AHP) for decision-making. Two direct manipulation tools, presented metaphorically as a “pump” and a “hook,” were developed and applied to the treemap to support AHP sensitivity analysis. Users can change the importance of criteria dynamically on the two-dimensional treemap and immediately see the impact on the outcome of the decision. This fluid process dramatically speeds up exploration and provides a better understanding of the relative impact of the component criteria. A usability study with six subjects using a prototype AHP application showed that treemap representation was acceptable from a visualization and data operation standpoint. VL - 6 SN - 1047-7047, 1526-5536 UR - http://isr.journal.informs.org/content/6/4/357 CP - 4 M3 - 10.1287/isre.6.4.357 ER - TY - JOUR T1 - Vision and action JF - Image and Vision Computing Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. KW - active vision KW - perceptual system design and analysis KW - vision system architecture AB - Our work on active vision has recently focused on the computational modelling of navigational tasks, where our investigations were guided by the idea of approaching vision for behavioural systems in the form of modules that are directly related to perceptual tasks. These studies led us to branch in various directions and inquire into the problems that have to be addressed in order to obtain an overall understanding of perceptual systems. In this paper, we present our views about the architecture of vision systems, about how to tackle the design and analysis of perceptual systems, and promising future research directions. Our suggested approach for understanding behavioural vision to realize the relationships of perception and action builds on two earlier approaches, the Medusa philosophy1 and the Synthetic approach2. The resulting framework calls for synthesizing an artificial vision system by studying vision competences of increasing complexity and, at the same time, pursuing the integration of the perceptual components with action and learning modules. We expect that computer vision research in the future will progress in tight collaboration with many other disciplines that are concerned with empirical approaches to vision, i.e. the understanding of biological vision. Throughout the paper, we describe biological findings that motivate computational arguments which we believe will influence studies of computer vision in the near future. VL - 13 SN - 0262-8856 UR - http://www.sciencedirect.com/science/article/pii/026288569598754H CP - 10 M3 - 10.1016/0262-8856(95)98754-H ER - TY - JOUR T1 - Vision and action* 1 JF - Image and vision computing Y1 - 1995 A1 - Fermüller, Cornelia A1 - Aloimonos, J. VL - 13 CP - 10 ER - TY - JOUR T1 - Vision, Graphic Design, and Visual Display JF - Readings in human-computer interaction: toward the year 2000 Y1 - 1995 A1 - Marcus,A. A1 - Murch,G.M. A1 - Baecker,R. A1 - Small,I. A1 - Mander,R. A1 - Ahlberg,C. A1 - Shneiderman, Ben ER - TY - CONF T1 - Visual decision-making: using treemaps for the analytic hierarchy process T2 - Conference companion on Human factors in computing systems Y1 - 1995 A1 - Asahi,Toshiyuki A1 - Turo,David A1 - Shneiderman, Ben JA - Conference companion on Human factors in computing systems T3 - CHI '95 PB - ACM CY - New York, NY, USA SN - 0-89791-755-3 UR - http://doi.acm.org/10.1145/223355.223747 M3 - 10.1145/223355.223747 ER - TY - JOUR T1 - Windows of opportunity in electronic classrooms JF - Communications of the ACM Y1 - 1995 A1 - Shneiderman, Ben A1 - Alavi,Maryann A1 - Norman,Kent A1 - Borkowski,Ellen Yu AB - Paradigm-shifting landmark buildings are cherished by their occupants and remembered because they reshape our expectations of schools, homes, or offices. Classic examples include Thomas Jefferson's communal design of the “academical village” at the University of Virginia where faculty and students lived close to classrooms, Frank Lloyd Wright's organic harmony with nature in Fallingwater (in western Pennsylvania) where the waterfall sounds and leafy surroundings offered a stress-reducing getaway for an urban executive, or Kevin Roche's open glass-walled Ford Foundation (in New York City) that promoted new team-oriented management strategies. VL - 38 SN - 0001-0782 UR - http://doi.acm.org/10.1145/219717.219725 CP - 11 M3 - 10.1145/219717.219725 ER - TY - CONF T1 - The alphaslider: a compact and rapid selector T2 - Proceedings of the SIGCHI conference on Human factors in computing systems: celebrating interdependence Y1 - 1994 A1 - Ahlberg,Christopher A1 - Shneiderman, Ben KW - Alphaslider KW - dynamic queries KW - menus KW - selection technology KW - widget JA - Proceedings of the SIGCHI conference on Human factors in computing systems: celebrating interdependence T3 - CHI '94 PB - ACM CY - New York, NY, USA SN - 0-89791-650-6 UR - http://doi.acm.org/10.1145/191666.191790 M3 - 10.1145/191666.191790 ER - TY - JOUR T1 - Cortical map reorganization as a competitive process JF - Neural Computation Y1 - 1994 A1 - Sutton III,G. G. A1 - Reggia, James A. A1 - Armentrout,S. L A1 - D'Autrechy,C. L VL - 6 CP - 1 ER - TY - JOUR T1 - Design and implementation of Maruti-II JF - Principles of Real-Time Systems. Prentice Hall Y1 - 1994 A1 - Saksena,M. A1 - da Silva,J. A1 - Agrawala, Ashok K. ER - TY - JOUR T1 - Dynamic algorithms for geometric spanners of small diameter: Randomized solutions JF - Computational Geometry: Theory and Applications Y1 - 1994 A1 - Arya,Sunil A1 - Mount, Dave A1 - Smid,Michiel AB - Let S be a set of n points in IR d and let t ? 1 be a real number. A t-spanner for S is a directed graph having the points of S as its vertices, such that for any pair p and q of points there is a path from p to q of length at most t times the Euclidean distance between p and q. Such a path is called a t-spanner path. The spanner diameter of such a spanner is defined as the smallest integer D such that for any pair p and q of points there is a t-spanner path from p to q containing at most D edges. A randomized algorithm is given for constructing a t-spanner that, with high probability, contains O(n) edges and has spanner diameter O(log n). A data structure of size O(n log d n) is given that maintains this t-spanner in O(log d n log log n) expected amortized time per insertion and deletion, in the model of random updates, as introduced by Mulmuley. Keywords: Computational geometry, proximity problems, skip lists, randomization, dynamic data structures. Preprint submitted to Els... VL - 13 ER - TY - CONF T1 - Efficient runtime support for parallelizing block structured applications T2 - Scalable High-Performance Computing Conference, 1994., Proceedings of the Y1 - 1994 A1 - Agrawal,G. A1 - Sussman, Alan A1 - Saltz, J. KW - application programmers KW - block structured applications KW - distributed memory parallel machines KW - distributed memory systems KW - engineering applications KW - irregularly coupled regular mesh problems KW - machine-independent KW - multiblock KW - multiblock computational fluid dynamics code KW - multiblock template KW - multigrid codes KW - Parallel machines KW - parallel programming KW - Physics computing KW - runtime communication overhead KW - Runtime library KW - runtime support KW - scientific applications KW - software reusability KW - structured meshes AB - Scientific and engineering applications often involve structured meshes. These meshes may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). We describe a runtime library for parallelizing these applications on distributed memory parallel machines in an efficient and machine-independent fashion. This runtime library is implemented on several different systems. This library can be used by application programmers to port applications by hand and can also be used by a compiler to handle communication for these applications. Our experimental results show that our primitives have low runtime communication overheads. We have used this library to port a multiblock template and a multigrid code. Effort is also underway to port a complete multiblock computational fluid dynamics code using our library JA - Scalable High-Performance Computing Conference, 1994., Proceedings of the M3 - 10.1109/SHPCC.1994.296639 ER - TY - JOUR T1 - Error propagation in 3D-from-2D recognition: Scaled-orthographic and perspective projections JF - Proceedings: ARPA Image Understanding Workshop, Monterey, California Y1 - 1994 A1 - Alter,T. D. A1 - Jacobs, David W. AB - Robust recognition systems require a careful under-standing of the e ects of error in sensed features. Error in these image features results in uncertainty in the possible image location of each additional model feature. We present an accurate, analytic ap- proximation for this uncertainty when model poses are based on matching three image and model points. This result applies to objects that are fully three- dimensional, where past results considered only two- dimensional objects. Further, we introduce a lin- ear programming algorithm to compute this uncer- tainty when poses are based on any number of initial matches. ER - TY - CONF T1 - Error propagation in full 3D-from-2D object recognition T2 - Computer Vision and Pattern Recognition, 1994. Proceedings CVPR '94., 1994 IEEE Computer Society Conference on Y1 - 1994 A1 - Alter,T. D. A1 - Jacobs, David W. KW - 3D-from-2D KW - algorithm; KW - error KW - extraction; KW - feature KW - features; KW - handling; KW - image KW - initial KW - linear KW - matches; KW - object KW - Programming KW - programming; KW - propagation; KW - recognition KW - recognition; KW - robust KW - sequences; KW - systems; KW - Uncertainty KW - uncertainty; AB - Robust recognition systems require a careful understanding of the effects of error in sensed features. Error in these image features results in uncertainty in the possible image location of each additional model feature. We present an accurate, analytic approximation for this uncertainty when model poses are based on matching three image and model points. This result applies to objects that are fully three-dimensional, where past results considered only two-dimensional objects. Further, we introduce a linear programming algorithm to compute this uncertainty when poses are based on any number of initial matches JA - Computer Vision and Pattern Recognition, 1994. Proceedings CVPR '94., 1994 IEEE Computer Society Conference on M3 - 10.1109/CVPR.1994.323920 ER - TY - JOUR T1 - Estimating the heading direction using normal flow JF - International Journal of Computer Vision Y1 - 1994 A1 - Aloimonos, J. A1 - Duric, Z. VL - 13 CP - 1 ER - TY - BOOK T1 - Fault tolerant system design Y1 - 1994 A1 - Levi,Shem-Tov A1 - Agrawala, Ashok K. KW - Computers / Intelligence (AI) & Semantics KW - Computers / Programming Languages / General KW - Computers / Software Development & Engineering / Systems Analysis & Design KW - Reference / General KW - Technology & Engineering / Engineering (General) AB - This book presents a comprehensive exploration of the practical issues, tested techniques, and accepted theory for developing fault tolerant systems. It is a ready reference to work already done in the field, with new approaches devised by the authors. PB - McGraw-Hill SN - 9780070375154 ER - TY - JOUR T1 - How normal flow constrains relative depth for an active observer JF - Image and vision computing Y1 - 1994 A1 - Huang, L. A1 - Aloimonos, J. VL - 12 CP - 7 ER - TY - CONF T1 - Integrated approaches for improving the effectiveness of Plan Reuse (A Progress Report) T2 - ARPA/Rome Laboratory knowledge-based planning and scheduling initiative: workshop proceedings: Tuscon, Arizona, February 21-24, 1994 Y1 - 1994 A1 - Kambhampati,S. A1 - Ihrig,L. A1 - Katukam,S. A1 - Chen,J. A1 - Hendler,J. A A1 - Agrawala, Ashok K. JA - ARPA/Rome Laboratory knowledge-based planning and scheduling initiative: workshop proceedings: Tuscon, Arizona, February 21-24, 1994 ER - TY - JOUR T1 - Mission-oriented replication of periodic tasks in real-time distributed systems JF - Computer Science Technical Report Series; Vol. CS-TR-3256 Y1 - 1994 A1 - Cheng,S. T A1 - Hwang,S. I A1 - Agrawala, Ashok K. ER - TY - JOUR T1 - A neural model of cortical map reorganization following a focal lesion JF - Artificial Intelligence in Medicine Y1 - 1994 A1 - Armentrout,S. L A1 - Reggia, James A. A1 - Weinrich,M. VL - 6 CP - 5 ER - TY - RPRT T1 - Next Generation Network Management Technology Y1 - 1994 A1 - Atallah,George C A1 - Ball,Michael O A1 - Baras,John S A1 - Goli,Shravan K A1 - Karne,Ramesh K A1 - Kelley,Stephen A1 - Kumar,Harsha P. A1 - Plaisant, Catherine A1 - Roussopoulos, Nick A1 - Shneiderman, Ben A1 - Srinivasarao,Mulugu A1 - Stathatos,Kostas A1 - Teittinen,Marko A1 - Whitefield,David KW - Constraints for Network Management. KW - Network Configuration Management KW - network management KW - Object Oriented Data Base Model for Network Management KW - Rules KW - Systems Integration KW - Visual Information Management for Network Configuration Management AB - Today's telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be ﲭixed media (copper, fiber- optic, radio, and satellite); the sub networks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be ﲭultimedia (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g. data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object-oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment.- A revised version of this technical report has been published in