TY - JOUR T1 - TIGRFAMs and Genome Properties in 2013. JF - Nucleic Acids Res Y1 - 2013 A1 - Haft, Daniel H A1 - Jeremy D Selengut A1 - Richter, Roland A A1 - Harkins, Derek A1 - Basu, Malay K A1 - Beck, Erin KW - Databases, Protein KW - Genome, Archaeal KW - Genome, Bacterial KW - Genomics KW - Internet KW - Markov chains KW - Molecular Sequence Annotation KW - Proteins KW - sequence alignment AB -

TIGRFAMs, available online at http://www.jcvi.org/tigrfams is a database of protein family definitions. Each entry features a seed alignment of trusted representative sequences, a hidden Markov model (HMM) built from that alignment, cutoff scores that let automated annotation pipelines decide which proteins are members, and annotations for transfer onto member proteins. Most TIGRFAMs models are designated equivalog, meaning they assign a specific name to proteins conserved in function from a common ancestral sequence. Models describing more functionally heterogeneous families are designated subfamily or domain, and assign less specific but more widely applicable annotations. The Genome Properties database, available at http://www.jcvi.org/genome-properties, specifies how computed evidence, including TIGRFAMs HMM results, should be used to judge whether an enzymatic pathway, a protein complex or another type of molecular subsystem is encoded in a genome. TIGRFAMs and Genome Properties content are developed in concert because subsystems reconstruction for large numbers of genomes guides selection of seed alignment sequences and cutoff values during protein family construction. Both databases specialize heavily in bacterial and archaeal subsystems. At present, 4284 models appear in TIGRFAMs, while 628 systems are described by Genome Properties. Content derives both from subsystem discovery work and from biocuration of the scientific literature.

VL - 41 CP - Database issue M3 - 10.1093/nar/gks1234 ER - TY - CONF T1 - Networking lessons: From computers to water T2 - 2012 Fourth International Conference on Communication Systems and Networks (COMSNETS) Y1 - 2012 A1 - Narayanan,I. A1 - Sarangan,V. A1 - Vasan, A. A1 - Srinivasan, Aravind A1 - Sivasubramaniam,A. KW - Biological cells KW - computer networking KW - Computer networks KW - COMPUTERS KW - energy footprint KW - Genetic algorithms KW - green nonIT domains KW - infrastructure enhancement problem KW - Internet KW - network theory (graphs) KW - networking lessons KW - planning KW - pricing KW - water distribution networks KW - water supply KW - water utility network AB - As an instance of using IT to green non-IT domains, we consider the question whether lessons from computer networking can be applied in water distribution networks to improve their energy footprint and/or efficiency. Our contributions in this work are: (i) we identify several areas where principles from computer networking can be used to better water distribution; (ii) we focus on a specific infrastructure enhancement problem caused by increasing demands on a water utility network and present solutions (similar to those used in computer networks) that optimize both operational expenditure and total cost of ownership. We validate our solutions through simulations and compare their efficacy against techniques that are traditionally used in enhancing water networks. Our results show that lessons from computer networks can help in enhancing water networks. JA - 2012 Fourth International Conference on Communication Systems and Networks (COMSNETS) PB - IEEE SN - 978-1-4673-0296-8 M3 - 10.1109/COMSNETS.2012.6151373 ER - TY - CONF T1 - You'Re Capped: Understanding the Effects of Bandwidth Caps on Broadband Use in the Home T2 - SIGCHI '12 Y1 - 2012 A1 - Marshini Chetty A1 - Banks, Richard A1 - Brush, A.J. A1 - Donner, Jonathan A1 - Grinter, Rebecca KW - Bandwidth KW - bandwidth cap KW - data cap KW - Internet KW - metered use KW - pricing KW - usage-based billing KW - usage-based pricing AB - Bandwidth caps, a limit on the amount of data users can upload and download in a month, are common globally for both home and mobile Internet access. With caps, each bit of data consumed comes at a cost against a monthly quota or a running tab. Yet, relatively little work has considered the implications of this usage-based pricing model on the user experience. In this paper, we present results from a qualitative study of households living with bandwidth caps. Our findings suggest home users grapple with three uncertainties regarding their bandwidth usage: invisible balances, mysterious processes, and multiple users. We discuss how these uncertainties impact their usage and describe the potential for better tools to help monitor and manage data caps. We conclude that as a community we need to cater for users under Internet cost constraints. JA - SIGCHI '12 T3 - CHI '12 PB - ACM SN - 978-1-4503-1015-4 UR - http://doi.acm.org/10.1145/2207676.2208714 ER - TY - CONF T1 - Comparing Social Tags to Microblogs T2 - Privacy, security, risk and trust (passat), 2011 IEEE third international conference on and 2011 IEEE third international conference on social computing (socialcom) Y1 - 2011 A1 - Lai,V. A1 - Rajashekar,C. A1 - Rand, William KW - (online); KW - album;online KW - commerce;information KW - correlation KW - document KW - frequency-inverse KW - frequency;electronic KW - Internet KW - measure;social KW - measures;similarity KW - media;rank KW - networking KW - retrieval;microblog;music KW - retrieval;music;social KW - social KW - tags;term KW - usage;Twitter;e-commerce;information AB - As Internet usage and e-commerce grow, online social media serve as popular outlets for consumers to express sentiments about products. On Amazon, users can tag an album with a keyword, while tweets on Twitter represent a more natural conversation. The differing natures of these media make them difficult to compare. This project collects and analyzes social media data for newly released music albums and develops new methods of comparing a product's social tags to its microblogging data. It explores information retrieval and rank correlation measures as similarity measures, as well as term frequency-inverse document frequency (tf-idf) processing. We conclude that with sufficient Twitter activity about an album, social tags do represent the most frequent conversations occurring on Twitter. These results imply that managers can collect and analyze tags and use them as a proxy for most common consumer feedback from microblogging, which is more difficult to collect. JA - Privacy, security, risk and trust (passat), 2011 IEEE third international conference on and 2011 IEEE third international conference on social computing (socialcom) M3 - 10.1109/PASSAT/SocialCom.2011.52 ER - TY - CONF T1 - Decentralized, accurate, and low-cost network bandwidth prediction T2 - 2011 Proceedings IEEE INFOCOM Y1 - 2011 A1 - Sukhyun Song A1 - Keleher,P. A1 - Bhattacharjee, Bobby A1 - Sussman, Alan KW - accuracy KW - approximate tree metric space KW - Bandwidth KW - bandwidth allocation KW - bandwidth measurement KW - decentralized low cost system KW - distributed tree KW - end-to-end prediction KW - Extraterrestrial measurements KW - Internet KW - low-cost network bandwidth prediction KW - Measurement uncertainty KW - pairwise bandwidth KW - Peer to peer computing KW - Prediction algorithms KW - trees (mathematics) AB - The distributed nature of modern computing makes end-to-end prediction of network bandwidth increasingly important. Our work is inspired by prior work that treats the Internet and bandwidth as an approximate tree metric space. This paper presents a decentralized, accurate, and low cost system that predicts pairwise bandwidth between hosts. We describe an algorithm to construct a distributed tree that embeds bandwidth measurements. The correctness of the algorithm is provable when driven by precise measurements. We then describe three novel heuristics that achieve high accuracy for predicting bandwidth even with imprecise input data. Simulation experiments with a real-world dataset confirm that our approach shows high accuracy with low cost. JA - 2011 Proceedings IEEE INFOCOM PB - IEEE SN - 978-1-4244-9919-9 M3 - 10.1109/INFCOM.2011.5935251 ER - TY - JOUR T1 - Developing a Single Model and Test Prioritization Strategies for Event-Driven Software JF - Software Engineering, IEEE Transactions on Y1 - 2011 A1 - Bryce,R.C. A1 - Sampath,S. A1 - Memon, Atif M. KW - EDS KW - event-driven software KW - graphical user interface KW - Graphical user interfaces KW - GUI testing KW - Internet KW - program testing KW - service-oriented architecture KW - test prioritization strategy KW - Web application testing AB - Event-Driven Software (EDS) can change state based on incoming events; common examples are GUI and Web applications. These EDSs pose a challenge to testing because there are a large number of possible event sequences that users can invoke through a user interface. While valuable contributions have been made for testing these two subclasses of EDS, such efforts have been disjoint. This work provides the first single model that is generic enough to study GUI and Web applications together. In this paper, we use the model to define generic prioritization criteria that are applicable to both GUI and Web applications. Our ultimate goal is to evolve the model and use it to develop a unified theory of how all EDS should be tested. An empirical study reveals that the GUI and Web-based applications, when recast using the new model, show similar behavior. For example, a criterion that gives priority to all pairs of event interactions did well for GUI and Web applications; another criterion that gives priority to the smallest number of parameter value settings did poorly for both. These results reinforce our belief that these two subclasses of applications should be modeled and studied together. VL - 37 SN - 0098-5589 CP - 1 M3 - 10.1109/TSE.2010.12 ER - TY - CONF T1 - Predicting Trust and Distrust in Social Networks T2 - Privacy, Security, Risk and Trust (PASSAT), 2011 IEEE Third International Conference on and 2011 IEEE Third International Confernece on Social Computing (SocialCom) Y1 - 2011 A1 - DuBois,T. A1 - Golbeck,J. A1 - Srinivasan, Aravind KW - distrust prediction KW - Electronic publishing KW - Encyclopedias KW - graph theory KW - inference algorithm KW - Inference algorithms KW - inference mechanisms KW - Internet KW - negative trust KW - online social networks KW - positive trust KW - Prediction algorithms KW - probability KW - random graphs KW - security of data KW - social media KW - social networking (online) KW - spring-embedding algorithm KW - Training KW - trust inference KW - trust probabilistic interpretation KW - user behavior KW - user satisfaction KW - user-generated content KW - user-generated interactions AB - As user-generated content and interactions have overtaken the web as the default mode of use, questions of whom and what to trust have become increasingly important. Fortunately, online social networks and social media have made it easy for users to indicate whom they trust and whom they do not. However, this does not solve the problem since each user is only likely to know a tiny fraction of other users, we must have methods for inferring trust - and distrust - between users who do not know one another. In this paper, we present a new method for computing both trust and distrust (i.e., positive and negative trust). We do this by combining an inference algorithm that relies on a probabilistic interpretation of trust based on random graphs with a modified spring-embedding algorithm. Our algorithm correctly classifies hidden trust edges as positive or negative with high accuracy. These results are useful in a wide range of social web applications where trust is important to user behavior and satisfaction. JA - Privacy, Security, Risk and Trust (PASSAT), 2011 IEEE Third International Conference on and 2011 IEEE Third International Confernece on Social Computing (SocialCom) PB - IEEE SN - 978-1-4577-1931-8 M3 - 10.1109/PASSAT/SocialCom.2011.56 ER - TY - CONF T1 - Joint analysis of network incidents and intradomain routing changes T2 - Network and Service Management (CNSM), 2010 International Conference on Y1 - 2010 A1 - Medem,A. A1 - Teixeira,R. A1 - Feamster, Nick A1 - Meulle,M. KW - correlation method KW - Internet KW - Internet2 backbone network KW - intradomain routing instability KW - network maintenance KW - network routing joint analysis KW - telecommunication network routing KW - Virtual private networks KW - VPN provider AB - This paper studies how intradomain routing instability relates to events in network trouble tickets for two networks: a VPN provider and the Internet2 backbone network. Our goal in performing this joint analysis of routing and trouble tickets is to better understand the likely underlying causes of intradomain routing instability. We develop a method to correlate trouble tickets with instability events and find that, although unplanned events last longer than scheduled maintenance, there is no single underlying cause for most instability, and that these causes differ across networks. In comparison to a similar study from Labovitz et al. from ten years ago, we find that, while certain causes of instability such as maintenance and circuit problems remain significant, power issues have become much less prevalent, and software-related problems have become more common. JA - Network and Service Management (CNSM), 2010 International Conference on M3 - 10.1109/CNSM.2010.5691306 ER - TY - JOUR T1 - Video Précis: Highlighting Diverse Aspects of Videos JF - IEEE Transactions on Multimedia Y1 - 2010 A1 - Shroff, N. A1 - Turaga,P. A1 - Chellapa, Rama KW - $K$-means KW - CAMERAS KW - combinatorial mathematics KW - combinatorial optimization KW - Cost function KW - data compression KW - Exemplar selection KW - Image segmentation KW - Internet KW - Iron KW - Length measurement KW - multimedia systems KW - Ncut KW - optimisation KW - Optimization methods KW - original video KW - Permission KW - shot segmentation KW - Surveillance KW - user specified summary length KW - video précis KW - Video sharing KW - video signal processing KW - Video summarization AB - Summarizing long unconstrained videos is gaining importance in surveillance, web-based video browsing, and video-archival applications. Summarizing a video requires one to identify key aspects that contain the essence of the video. In this paper, we propose an approach that optimizes two criteria that a video summary should embody. The first criterion, “coverage,” requires that the summary be able to represent the original video well. The second criterion, “diversity,” requires that the elements of the summary be as distinct from each other as possible. Given a user-specified summary length, we propose a cost function to measure the quality of a summary. The problem of generating a précis is then reduced to a combinatorial optimization problem of minimizing the proposed cost function. We propose an efficient method to solve the optimization problem. We demonstrate through experiments (on KTH data, unconstrained skating video, a surveillance video, and a YouTube home video) that optimizing the proposed criterion results in meaningful video summaries over a wide range of scenarios. Summaries thus generated are then evaluated using both quantitative measures and user studies. VL - 12 SN - 1520-9210 CP - 8 M3 - 10.1109/TMM.2010.2058795 ER - TY - CONF T1 - ApproxRank: Estimating Rank for a Subgraph T2 - IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 Y1 - 2009 A1 - Yao Wu A1 - Raschid, Louiqa KW - Application software KW - ApproxRank KW - Computer applications KW - Crawlers KW - customized semantic query answering KW - Data engineering KW - Educational institutions KW - Explosions KW - focused crawlers KW - global Web graph KW - graph theory KW - IdealRank algorithm KW - Internet KW - localized search engines KW - PageRank-style KW - personalized search KW - Query processing KW - Runtime KW - Search engines KW - Stochastic processes KW - Web pages AB - Customized semantic query answering, personalized search, focused crawlers and localized search engines frequently focus on ranking the pages contained within a subgraph of the global Web graph. The challenge for these applications is to compute PageRank-style scores efficiently on the subgraph, i.e., the ranking must reflect the global link structure of the Web graph but it must do so without paying the high overhead associated with a global computation. We propose a framework of an exact solution and an approximate solution for computing ranking on a subgraph. The IdealRank algorithm is an exact solution with the assumption that the scores of external pages are known. We prove that the IdealRank scores for pages in the subgraph converge. Since the PageRank-style scores of external pages may not typically be available, we propose the ApproxRank algorithm to estimate scores for the subgraph. Both IdealRank and ApproxRank represent the set of external pages with an external node L1 and extend the subgraph with links to L1. They also modify the PageRank-style transition matrix with respect to L1. We analyze the L1 distance between IdealRank scores and ApproxRank scores of the subgraph and show that it is within a constant factor of the L1 distance of the external pages (e.g., the true PageRank scores and uniform scores assumed by ApproxRank). We compare ApproxRank and a stochastic complementation approach (SC), a current best solution for this problem, on different types of subgraphs. ApproxRank has similar or superior performance to SC and typically improves on the runtime performance of SC by an order of magnitude or better. We demonstrate that ApproxRank provides a good approximation to PageRank for a variety of subgraphs. JA - IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 PB - IEEE SN - 978-1-4244-3422-0 M3 - 10.1109/ICDE.2009.108 ER - TY - CONF T1 - First Steps to Netviz Nirvana: Evaluating Social Network Analysis with NodeXL T2 - International Conference on Computational Science and Engineering, 2009. CSE '09 Y1 - 2009 A1 - Bonsignore,E. M A1 - Dunne,C. A1 - Rotman,D. A1 - Smith,M. A1 - Capone,T. A1 - Hansen,D. L A1 - Shneiderman, Ben KW - Computer science KW - computer science education KW - data visualisation KW - Data visualization KW - Educational institutions KW - graph drawing KW - graph layout algorithm KW - Information services KW - Information Visualization KW - Internet KW - Libraries KW - Microsoft Excel open-source template KW - MILC KW - multi-dimensional in-depth long-term case studies KW - Netviz Nirvana KW - NodeXL KW - Open source software KW - Programming profession KW - SNA KW - social network analysis KW - Social network services KW - social networking (online) KW - spreadsheet programs KW - structural relationship KW - teaching KW - visual analytics KW - visualization tool KW - Web sites AB - Social Network Analysis (SNA) has evolved as a popular, standard method for modeling meaningful, often hidden structural relationships in communities. Existing SNA tools often involve extensive pre-processing or intensive programming skills that can challenge practitioners and students alike. NodeXL, an open-source template for Microsoft Excel, integrates a library of common network metrics and graph layout algorithms within the familiar spreadsheet format, offering a potentially low-barrier-to-entry framework for teaching and learning SNA. We present the preliminary findings of 2 user studies of 21 graduate students who engaged in SNA using NodeXL. The majority of students, while information professionals, had little technical background or experience with SNA techniques. Six of the participants had more technical backgrounds and were chosen specifically for their experience with graph drawing and information visualization. Our primary objectives were (1) to evaluate NodeXL as an SNA tool for a broad base of users and (2) to explore methods for teaching SNA. Our complementary dual case-study format demonstrates the usability of NodeXL for a diverse set of users, and significantly, the power of a tightly integrated metrics/visualization tool to spark insight and facilitate sense-making for students of SNA. JA - International Conference on Computational Science and Engineering, 2009. CSE '09 PB - IEEE VL - 4 SN - 978-1-4244-5334-4 M3 - 10.1109/CSE.2009.120 ER - TY - CONF T1 - Web Monitoring 2.0: Crossing Streams to Satisfy Complex Data Needs T2 - IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 Y1 - 2009 A1 - Roitman,H. A1 - Gal,A. A1 - Raschid, Louiqa KW - Bandwidth KW - complex client information need KW - Data Delivery KW - Data engineering KW - database management systems KW - Educational institutions KW - Internet KW - Mashups KW - mashups generation KW - Monitoring KW - multiple information source KW - offline algorithmic solution KW - Portals KW - PROBES KW - Profiles KW - Query processing KW - scalability KW - scheduling KW - volatile information stream KW - Web 2.0 KW - Web Monitoring AB - Web monitoring 2.0 supports the complex information needs of clients who probe multiple information sources and generate mashups by integrating across these volatile streams. A proxy that aims at satisfying multiple customized client profiles will face a scalability challenge in trying to maximize the number of clients served while at the same time fully satisfying complex client needs. In this paper, we introduce an abstraction of complex execution intervals, a combination of time intervals and information streams, to capture complex client needs. Given some budgetary constraints (e.g., bandwidth), we present offline algorithmic solutions for the problem of maximizing completeness of capturing complex profiles. JA - IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 PB - IEEE SN - 978-1-4244-3422-0 M3 - 10.1109/ICDE.2009.204 ER - TY - CONF T1 - Bilateral symmetry of object silhouettes under perspective projection T2 - 19th International Conference on Pattern Recognition, 2008. ICPR 2008 Y1 - 2008 A1 - Bitsakos,K. A1 - Yi,H. A1 - Yi,L. A1 - Fermüller, Cornelia KW - Automation KW - bilateral symmetry KW - Computer vision KW - Frequency KW - Image analysis KW - Image coding KW - Image reconstruction KW - Internet KW - Internet images KW - Object detection KW - object silhouettes KW - perspective distortion KW - perspective projection KW - SHAPE KW - symmetric objects AB - Symmetry is an important property of objects and is exhibited in different forms e.g., bilateral, rotational, etc. This paper presents an algorithm for computing the bilateral symmetry of silhouettes of shallow objects under perspective distortion, exploiting the invariance of the cross ratio to projective transformations. The basic idea is to use the cross ratio to compute a number of midpoints of cross sections and then fit a straight line through them. The goodness-of-fit determines the likelihood of the line to be the axis of symmetry. We analytically estimate the midpointpsilas location as a function of the vanishing point for a given object silhouette. Hence finding the symmetry axis amounts to a 2D search in the space of vanishing points. We present experiments on two datasets as well as Internet images of symmetric objects that validate our approach. JA - 19th International Conference on Pattern Recognition, 2008. ICPR 2008 PB - IEEE SN - 978-1-4244-2174-9 M3 - 10.1109/ICPR.2008.4761501 ER - TY - CONF T1 - On the Comparison of Network Attack Datasets: An Empirical Analysis Y1 - 2008 A1 - Berthier,R. A1 - Korman,D. A1 - Michel Cukier A1 - Hiltunen,M. A1 - Vesonder,G. A1 - Sheleheda,D. KW - ATLAS KW - distributed network telescope KW - Internet KW - intrusion detection systems KW - network attack datasets KW - network malicious activity KW - network security operators KW - security of data AB - Network malicious activity can be collected and reported by various sources using different attack detection solutions. The granularity of these solutions provides either very detailed information (intrusion detection systems, honeypots) or high-level trends (CAIDA, SANS). The problem for network security operators is often to select the sources of information to better protect their network. How much information from these sources is redundant and how much is unique? The goal of this paper is to show empirically that while some global attack events can be correlated across various sensors, the majority of incoming malicious activity has local specificities. This study presents a comparative analysis of four different attack datasets offering three different levels of granularity: 1) two high interaction honeynets deployed at two different locations (i.e., a corporate and an academic environment); 2) ATLAS which is a distributed network telescope from Arbor; and 3) Internet Protecttrade which is a global alerting service from AT amp;T. M3 - 10.1109/HASE.2008.50 ER - TY - CONF T1 - On the Use of Security Metrics Based on Intrusion Prevention System Event Data: An Empirical Analysis Y1 - 2008 A1 - Chrun,D. A1 - Michel Cukier A1 - Sneeringer,G. KW - empirical analysis KW - Internet KW - Internet attack group KW - intrusion prevention system event data KW - network traffic monitoring KW - organization security metrics KW - security of data AB - With the increasing number of attacks on the Internet, a primary concern for organizations is the protection of their network. To do so, organizations install security devices such as intrusion prevention systems to monitor network traffic. However, data that are collected by these devices are often imperfect. The contribution of this paper is to try to define some practical metrics based on imperfect data collected by an intrusion prevention system. Since attacks greatly differ, we propose to group the attacks into several attack type groups. We then define a set of metrics for each attack type group. We introduce an approach that consists in analyzing the evolution of these metrics per attack type group by focusing on outliers in order to give an insight into an organizationpsilas security. The method is assessed for an organization of about 40,000 computers. The results were encouraging: outliers could be related to security issues that, in some cases, had not been previously flagged. M3 - 10.1109/HASE.2008.52 ER - TY - JOUR T1 - Browsing large online data tables using generalized query previews JF - Information Systems Y1 - 2007 A1 - Tanin,Egemen A1 - Shneiderman, Ben A1 - Xie,Hairuo KW - Information Visualization KW - Internet KW - Online querying KW - World-wide web AB - Companies, government agencies, and other organizations are making their data available to the world over the Internet. They often use large online relational tables for this purpose. Users query such tables with front-ends that typically use menus or form fillin interfaces, but these interfaces rarely give users information about the contents and distribution of the data. Such a situation leads users to waste time and network/server resources posing queries that have zero- or mega-hit results. Generalized query previews enable efficient browsing of large online data tables by supplying data distribution information to users. The data distribution information provides continuous feedback about the size of the result set as the query is being formed. Our paper presents a new user interface architecture and discusses three controlled experiments (with 12, 16, and 48 participants). Our prototype systems provide flexible user interfaces for research and testing of the ideas. The user studies show that for exploratory querying tasks, generalized query previews can speed user performance for certain user domains and can reduce network/server load. VL - 32 SN - 0306-4379 UR - http://www.sciencedirect.com/science/article/pii/S0306437905001213 CP - 3 M3 - 10.1016/j.is.2005.12.006 ER - TY - CONF T1 - Configuration Reasoning and Ontology For Web T2 - IEEE International Conference on Services Computing, 2007. SCC 2007 Y1 - 2007 A1 - Dana Dachman-Soled A1 - Sreedhar, V.C. KW - Apache server KW - Application software KW - configuration management KW - configuration reasoning KW - configuration space KW - File servers KW - Information security KW - Internet KW - knowledge representation languages KW - logical framework KW - logical reasoning KW - ontologies KW - ontologies (artificial intelligence) KW - Orbital robotics KW - OWL KW - path planning KW - Robot kinematics KW - Runtime environment KW - Taxonomy KW - Web infrastructures management KW - Web ontology language KW - Web server AB - Configuration plays a central role in the deployment and management of Web infrastructures and applications. A configuration often consists of assigning "values" to a pre-defined set of parameters defined in one or more files. Although the task of assigning values to (configuration) parameters looks simple, configuring infrastructures and applications is a very complex process. In this paper we present a framework for defining and analyzing configuration of an Apache server. We define the notion of "configuration space" of an Apache server as a set of possible values that can be assigned to configuration parameters. We then define the notion of an "obstacle" and "forbidden region" in the configuration space that should be avoided. We model configuration space using a logical framework based on OWL (Web ontology language). The obstacles and forbidden regions in the configuration space are modeled as constraints in the logical framework. These obstacles and forbidden regions are essentially "anti-patterns" that a typical installation should avoid. Given an instance of a configuration (that is, a "point" in the configuration space) we then check if the instance is "obstacle free" using logical reasoning. JA - IEEE International Conference on Services Computing, 2007. SCC 2007 ER - TY - JOUR T1 - Implications of Autonomy for the Expressiveness of Policy Routing JF - Networking, IEEE/ACM Transactions on Y1 - 2007 A1 - Feamster, Nick A1 - Johari,R. A1 - Balakrishnan,H. KW - autonomous systems KW - global Internet connectivity KW - interdomain routing system KW - Internet KW - next-hop rankings KW - routing protocol KW - routing protocols KW - routing stability KW - stable path assignment AB - Thousands of competing autonomous systems must cooperate with each other to provide global Internet connectivity. Each autonomous system (AS) encodes various economic, business, and performance decisions in its routing policy. The current interdomain routing system enables each AS to express policy using rankings that determine how each router in the AS chooses among different routes to a destination, and filters that determine which routes are hidden from each neighboring AS. Because the Internet is composed of many independent, competing networks, the interdomain routing system should provide autonomy, allowing network operators to set their rankings independently, and to have no constraints on allowed filters. This paper studies routing protocol stability under these conditions. We first demonstrate that ldquonext-hop rankings,rdquo commonly used in practice, may not ensure routing stability. We then prove that, when providers can set rankings and filters autonomously, guaranteeing that the routing system will converge to a stable path assignment imposes strong restrictions on the rankings ASes are allowed to choose. We discuss the implications of these results for the future of interdomain routing. VL - 15 SN - 1063-6692 CP - 6 M3 - 10.1109/TNET.2007.896531 ER - TY - CONF T1 - Measuring the Contributions of Routing Dynamics to Prolonged End-to-End Internet Path Failures T2 - Global Telecommunications Conference, 2007. GLOBECOM '07. IEEE Y1 - 2007 A1 - Wang,Feng A1 - Feamster, Nick A1 - Gao,Lixin KW - diverse Internet topological testbed KW - Internet KW - prolonged end-to-end Internet path failure KW - routing dynamics KW - telecommunication network reliability KW - telecommunication network routing KW - telecommunication network topology AB - This paper studies the contributions of routing dynamics to the duration of long-lived end-to-end Internet path failures. Studies have shown that end-to-end Internet failures (periods of prolonged packet loss) are widespread. These failures are typically attributed to either congestion or routing dynamics. Unfortunately, the extent to which congestion and routing dynamics contribute to long-lasting path failures, and the effect of routing dynamics on end-to-end performance, are not well understood. This paper uses a joint analysis of active measurements and routing data to characterize end-to-end failures observed over one month on a topologically diverse Internet testbed. We find that routing dynamics coincide with most prolonged end-to-end failures, suggesting that routing dynamics contribute significantly to the duration of these failures. We also find that most long-lived end-to-end path failures that coincide with routing dynamics are caused by BGP convergence or instability. Our results provide new insights into the effects of routing instability on end-to-end Internet path performance. JA - Global Telecommunications Conference, 2007. GLOBECOM '07. IEEE M3 - 10.1109/GLOCOM.2007.357 ER - TY - CONF T1 - Eye of the Beholder: Phone-Based Text-Recognition for the Visually-Impaired T2 - 2006 10th IEEE International Symposium on Wearable Computers Y1 - 2006 A1 - Tudor Dumitras A1 - Lee, M. A1 - Quinones, P. A1 - Smailagic, A. A1 - Siewiorek, Dan A1 - Narasimhan, P. KW - CAMERAS KW - data mining KW - handicapped aids KW - Hardware KW - Image quality KW - Internet KW - Land mobile radio cellular systems KW - Mobile computing KW - mobile handsets KW - mobile text-recognition system KW - Optical character recognition software KW - phone-based text-recognition KW - Product safety KW - Text recognition KW - visually-impaired AB - Blind and visually-impaired people cannot access essential information in the form of written text in our environment (e.g., on restaurant menus, street signs, door labels, product names and instructions, expiration dates). In this paper, we present and evaluate a mobile text-recognition system capable of extracting written information from a wide variety of sources and communicating it on-demand to the user. The user needs no additional hardware except an ordinary, Internet- enabled mobile camera-phone - a device that many visually-impaired individuals already own. This approach fills a gap in assistive technologies for the visually- impaired because it makes users aware of textual information not available to them through any other means. JA - 2006 10th IEEE International Symposium on Wearable Computers ER - TY - CONF T1 - Image Registration and Fusion Studies for the Integration of Multiple Remote Sensing Data T2 - Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on Y1 - 2006 A1 - Le Moigne,J. A1 - Cole-Rhodes,A. A1 - Eastman,R. A1 - Jain,P. A1 - Joshua,A. A1 - Memarsadeghi,N. A1 - Mount, Dave A1 - Netanyahu,N. A1 - Morisette,J. A1 - Uko-Ozoro,E. KW - ALI KW - EO-1 KW - fusion studies KW - geophysical signal processing KW - Hyperion sensors KW - image registration KW - Internet KW - multiple remote sensing data KW - multiple source data KW - Remote sensing KW - Web-based image registration toolbox AB - The future of remote sensing will see the development of spacecraft formations, and with this development will come a number of complex challenges such as maintaining precise relative position and specified attitudes. At the same time, there will be increasing needs to understand planetary system processes and build accurate prediction models. One essential technology to accomplish these goals is the integration of multiple source data. For this integration, image registration and fusion represent the first steps and need to be performed with very high accuracy. In this paper, we describe studies performed in both image registration and fusion, including a modular framework that was built to describe registration algorithms, a Web-based image registration toolbox, and the comparison of several image fusion techniques using data from the EO-1/ALI and Hyperion sensors JA - Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on VL - 5 M3 - 10.1109/ICASSP.2006.1661494 ER - TY - JOUR T1 - In VINI veritas: realistic and controlled network experimentation JF - SIGCOMM Comput. Commun. Rev. Y1 - 2006 A1 - Bavier,Andy A1 - Feamster, Nick A1 - Huang,Mark A1 - Peterson,Larry A1 - Rexford,Jennifer KW - architecture KW - experimentation KW - Internet KW - Routing KW - virtualization AB - This paper describes VINI, a virtual network infrastructure that allows network researchers to evaluate their protocols and services in a realistic environment that also provides a high degree of control over network conditions. VINI allows researchers to deploy and evaluate their ideas with real routing software, traffic loads, and network events. To provide researchers flexibility in designing their experiments, VINI supports simultaneous experiments with arbitrary network topologies on a shared physical infrastructure. This paper tackles the following important design question: What set of concepts and techniques facilitate flexible, realistic, and controlled experimentation (e.g., multiple topologies and the ability to tweak routing algorithms) on a fixed physical infrastructure? We first present VINI's high-level design and the challenges of virtualizing a single network. We then present PL-VINI, an implementation of VINI on PlanetLab, running the "Internet In a Slice". Our evaluation of PL-VINI shows that it provides a realistic and controlled environment for evaluating new protocols and services. VL - 36 SN - 0146-4833 UR - http://doi.acm.org/10.1145/1151659.1159916 CP - 4 M3 - 10.1145/1151659.1159916 ER - TY - JOUR T1 - Resilient multicast using overlays JF - IEEE/ACM Transactions on Networking Y1 - 2006 A1 - Banerjee,S. A1 - Lee,Seungjoon A1 - Bhattacharjee, Bobby A1 - Srinivasan, Aravind KW - application-layer multicast protocols KW - Computer science KW - Data communication KW - Delay KW - Internet KW - Internet-like topologies KW - IP networks KW - loss recovery technique KW - Multicast KW - multicast data recovery scheme KW - Multicast protocols KW - Network topology KW - NETWORKS KW - overlays KW - Performance loss KW - probabilistic forwarding KW - probabilistic resilient multicast KW - Protocols KW - Resilience KW - Streaming media KW - telecommunication network topology KW - Terminology AB - We introduce Probabilistic Resilient Multicast (PRM): a multicast data recovery scheme that improves data delivery ratios while maintaining low end-to-end latencies. PRM has both a proactive and a reactive components; in this paper we describe how PRM can be used to improve the performance of application-layer multicast protocols especially when there are high packet losses and host failures. Through detailed analysis in this paper, we show that this loss recovery technique has efficient scaling properties-the overheads at each overlay node asymptotically decrease to zero with increasing group sizes. As a detailed case study, we show how PRM can be applied to the NICE application-layer multicast protocol. We present detailed simulations of the PRM-enhanced NICE protocol for 10 000 node Internet-like topologies. Simulations show that PRM achieves a high delivery ratio (>97%) with a low latency bound (600 ms) for environments with high end-to-end network losses (1%-5%) and high topology change rates (5 changes per second) while incurring very low overheads (<5%). VL - 14 SN - 1063-6692 CP - 2 M3 - 10.1109/TNET.2006.872579 ER - TY - CONF T1 - Implications of autonomy for the expressiveness of policy routing T2 - Proceedings of the 2005 conference on Applications, technologies, architectures, and protocols for computer communications Y1 - 2005 A1 - Feamster, Nick A1 - Johari,Ramesh A1 - Balakrishnan,Hari KW - autonomy KW - BGP KW - Internet KW - policy KW - protocol KW - Routing KW - Safety KW - stability AB - Thousands of competing autonomous systems must cooperate with each other to provide global Internet connectivity. Each autonomous system (AS) encodes various economic, business, and performance decisions in its routing policy. The current interdomain routing system enables each AS to express policy using rankings that determine how each router inthe AS chooses among different routes to a destination, and filters that determine which routes are hidden from each neighboring AS. Because the Internet is composed of many independent, competing networks, the interdomain routing system should provide autonomy, allowing network operators to set their rankings independently, and to have no constraints on allowed filters. This paper studies routing protocol stability under these conditions. We first demonstrate that certain rankings that are commonly used in practice may not ensure routing stability. We then prove that, when providers can set rankings and filters autonomously, guaranteeing that the routing system will converge to a stable path assignment essentially requires ASes to rank routes based on AS-path lengths. We discuss the implications of these results for the future of interdomain routing. JA - Proceedings of the 2005 conference on Applications, technologies, architectures, and protocols for computer communications T3 - SIGCOMM '05 PB - ACM CY - New York, NY, USA SN - 1-59593-009-4 UR - http://doi.acm.org/10.1145/1080091.1080096 M3 - 10.1145/1080091.1080096 ER - TY - CONF T1 - ASPIRE: automated systematic protocol implementation robustness evaluation T2 - Software Engineering Conference, 2004. Proceedings. 2004 Australian Y1 - 2004 A1 - Vasan,Arunchandar A1 - Memon, Atif M. KW - algorithm KW - ASPIRE KW - automated systematic protocol KW - automated testing KW - fault tolerant computing KW - faulty PDU KW - formal specification KW - HTTP KW - implementation robustness evaluation KW - Internet KW - network protocol KW - protocol data unit KW - protocol specification KW - robustness testing KW - SMTP protocol KW - stateful protocols KW - stateless protocols KW - Transport protocols AB - Network protocol implementations are susceptible to problems caused by their lack of ability to handle invalid inputs. We present ASPIRE: automated systematic protocol implementation robustness evaluation, an automated approach to pro-actively test protocol implementations by observing their responses to faulty protocol data units (PDUs) or messages. In contrast to existing approaches, we sample the faulty PDU space in a systematic manner, thus allowing us to evaluate protocol implementations in the face of a wider variety of faulty PDUs. We use a pruning strategy to reduce, from exponential, the size of the faulty PDU set to polynomial in the number of fields of a PDU. We have implemented the ASPIRE algorithms and evaluated them on implementations of HTTP (Apache, Google Web Server (GWS), and Microsoft IIS) and SMTP (Sendmail and Microsoft Exchange) protocols. Our results show that Apache, GWS, and IIS, although implementing the same protocol specification, behave differently on faulty HTTP PDUs; Sendmail and exchange are different in handling our faulty SMTP PDUs. JA - Software Engineering Conference, 2004. Proceedings. 2004 Australian M3 - 10.1109/ASWEC.2004.1290477 ER - TY - CONF T1 - Automated cluster-based Web service performance tuning T2 - 13th IEEE International Symposium on High performance Distributed Computing, 2004. Proceedings Y1 - 2004 A1 - Chung,I. -H A1 - Hollingsworth, Jeffrey K KW - Active Harmony system KW - automated performance tuning KW - business KW - cluster-based Web service system KW - Clustering algorithms KW - Computer science KW - Educational institutions KW - electronic commerce KW - Internet KW - Middleware KW - performance evaluation KW - scalability KW - Throughput KW - Transaction databases KW - Web server KW - Web services KW - workstation clusters AB - Active harmony provides a way to automate performance tuning. We apply the Active Harmony system to improve the performance of a cluster-based web service system. The performance improvement cannot easily be achieved by tuning individual components for such a system. The experimental results show that there is no single configuration for the system that performs well for all kinds of workloads. By tuning the parameters, Active Harmony helps the system adapt to different workloads and improve the performance up to 16%. For scalability, we demonstrate how to reduce the time when tuning a large system with many tunable parameters. Finally an algorithm is proposed to automatically adjust the structure of cluster-based web systems, and the system throughput is improved up to 70% using this technique. JA - 13th IEEE International Symposium on High performance Distributed Computing, 2004. Proceedings PB - IEEE SN - 0-7695-2175-4 M3 - 10.1109/HPDC.2004.1323484 ER - TY - CONF T1 - Dynamic load balancing across mirrored multimedia servers T2 - 2003 International Conference on Multimedia and Expo, 2003. ICME '03. Proceedings Y1 - 2003 A1 - Matthur,A. A1 - Mundur, Padma KW - client-server systems KW - Delay KW - Internet KW - load balancing protocols KW - Load management KW - media streaming KW - metropolitan area network KW - metropolitan area networks KW - mirrored multimedia servers KW - Multimedia communication KW - multimedia servers KW - network packet loss KW - Network servers KW - packet transmission delay KW - Propagation losses KW - Protocols KW - Streaming media KW - Topology KW - Traffic control KW - Web server AB - The purpose of this paper is to present protocols for efficient load balancing across replicated multimedia servers in a metropolitan area network. Current multimedia infrastructures, even when they use mirrored servers, do not have standardized load balancing schemes. Existing schemes frequently require participation from the clients in balancing the load across the servers efficiently. We propose two protocols in this paper for fair load balancing without any client-side processing being required. Neither protocol requires any change to the network-level infrastructure. Using network packet loss and packet transmission delay as the chief metrics, we show the effectiveness of the protocols through extensive simulations. JA - 2003 International Conference on Multimedia and Expo, 2003. ICME '03. Proceedings PB - IEEE VL - 2 SN - 0-7803-7965-9 M3 - 10.1109/ICME.2003.1221551 ER - TY - JOUR T1 - A secure PLAN JF - IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews Y1 - 2003 A1 - Hicks, Michael W. A1 - Keromytis,A. D A1 - Smith,J. M KW - active networks KW - active-network firewall KW - Authentication KW - Authorization KW - Contracts KW - cryptography KW - Environmental management KW - Extraterrestrial measurements KW - functionally restricted packet language KW - general-purpose service routines KW - Internet KW - latency overhead KW - namespace-based security KW - packet switching KW - PLANet KW - Planets KW - privilege level KW - programmable networks KW - Safety KW - safety risks KW - secure PLAN KW - security of data KW - security risks KW - trust management KW - two-level architecture KW - virtual private network KW - Virtual private networks KW - Web and internet services AB - Active networks, being programmable, promise greater flexibility than current networks. Programmability, however, may introduce safety and security risks. This correspondence describes the design and implementation of a security architecture for the active network PLANet. Security is obtained with a two-level architecture that combines a functionally restricted packet language, PLAN, with an environment of general-purpose service routines governed by trust management. In particular, a technique is used which expands or contracts a packet's service environment based on its level of privilege, termed namespace-based security. The design and implementation of an active-network firewall and virtual private network is used as an application of the security architecture. Measurements of the system show that the addition of the firewall imposes an approximately 34% latency overhead and as little as a 6.7% space overhead to incoming packets. VL - 33 SN - 1094-6977 CP - 3 M3 - 10.1109/TSMCC.2003.817347 ER - TY - CONF T1 - On the use of flow migration for handling short-term overloads T2 - Global Telecommunications Conference, 2003. GLOBECOM '03. IEEE Y1 - 2003 A1 - Kuo,Kuo-Tung A1 - Phuvoravan,S. A1 - Bhattacharjee, Bobby A1 - Jun La,R. A1 - Shayman,M. A1 - Chang,Hyeong Soo KW - computing; KW - CONGESTION KW - congestion; KW - CONTROL KW - control; KW - dynamic KW - end-to-end KW - engineering KW - fast-timescale KW - flow KW - Internet KW - IP KW - label KW - long-term KW - mapping; KW - migration; KW - MPLS KW - multiprotocol KW - network KW - network; KW - networks; KW - of KW - optimal KW - overloads; KW - protocol; KW - QoS; KW - QUALITY KW - quality; KW - routers; KW - routing; KW - service; KW - set-up KW - short-term KW - software KW - software; KW - static KW - switching; KW - Telecommunication KW - telephony; KW - time; KW - transient KW - voice-over-IP; AB - In this work, we investigate flow migration as a mechanism to sustain QoS to network users during short-term overloads in the context of an MPLS IP network. We experiment with three different control techniques: static long-term optimal mapping of flows to LSPs; on-line locally optimal mapping of flows to LSPs at flow set-up time; and dynamic flow migration in response to transient congestion. These techniques are applicable over different timescales, have different run-time overheads, and require different levels of monitoring and control software inside the network. We present results both from detailed simulations and a complete implementation using software IP routers. We use voice-over-IP as our test application, and show that if end-to-end quality is to be maintained during short unpredictable bursts of high load, then a fast-timescale control such as migration is required. JA - Global Telecommunications Conference, 2003. GLOBECOM '03. IEEE VL - 6 M3 - 10.1109/GLOCOM.2003.1258807 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 - CONF T1 - Decoupled query optimization for federated database systems T2 - 18th International Conference on Data Engineering, 2002. Proceedings Y1 - 2002 A1 - Deshpande, Amol A1 - Hellerstein,J. M KW - Algorithm design and analysis KW - Cohera federated database KW - Computer science KW - Corporate acquisitions KW - Cost function KW - Database systems KW - decoupled optimization KW - Design optimization KW - distributed databases KW - federated databases KW - federated relational database systems KW - Internet KW - Query optimization KW - query optimizer KW - Query processing KW - Relational databases KW - Space exploration AB - We study the problem of query optimization in federated relational database systems. The nature of federated databases explicitly decouples many aspects of the optimization process, often making it imperative for the optimizer to consult underlying data sources while doing cost-based optimization. This not only increases the cost of optimization, but also changes the trade-offs involved in the optimization process significantly. The dominant cost in the decoupled optimization process is the "cost of costing" that traditionally has been considered insignificant. The optimizer can only afford a few rounds of messages to the underlying data sources and hence the optimization techniques in this environment must be geared toward gathering all the required cost information with minimal communication. In this paper, we explore the design space for a query optimizer in this environment and demonstrate the need for decoupling various aspects of the optimization process. We present minimum-communication decoupled variants of various query optimization techniques, and discuss tradeoffs in their performance in this scenario. We have implemented these techniques in the Cohera federated database system and our experimental results, somewhat surprisingly, indicate that a simple two-phase optimization scheme performs fairly well as long as the physical database design is known to the optimizer, though more aggressive algorithms are required otherwise JA - 18th International Conference on Data Engineering, 2002. Proceedings PB - IEEE SN - 0-7695-1531-2 M3 - 10.1109/ICDE.2002.994788 ER - TY - JOUR T1 - Embedded grammar tags: advancing natural language interaction on the Web JF - Intelligent Systems, IEEE Y1 - 2002 A1 - Dorai,G. K A1 - Yacoob,Yaser KW - embedded grammar tags KW - grammars KW - information content KW - information resources KW - intelligent agents KW - Internet KW - natural language interaction KW - natural language queries KW - natural languages KW - Search engines KW - semantic Web page representation KW - software agents KW - speech output generation KW - Speech recognition KW - speech recognition engines KW - Web page content AB - Embedded grammar tags (EGTs) reflect Web page content by anticipating queries users might launch to retrieve that content. The grammars provide a unifying component for speech recognition engines, semantic Web page representation, and speech output generation. We propose a new framework that lets intelligent agents discover accurate, concise responses to natural language queries. This framework's backbone consists of embedded grammar tags that capture natural language queries. EGTs reflect information content in Web pages by anticipating the queries that users might launch to retrieve particular content. VL - 17 SN - 1541-1672 CP - 1 M3 - 10.1109/5254.988450 ER - TY - CONF T1 - Experiences with capsule-based active networking T2 - DARPA Active NEtworks Conference and Exposition, 2002. Proceedings Y1 - 2002 A1 - Hicks, Michael W. A1 - Moore,J. T A1 - Wetherall,D. A1 - Nettles,S. KW - active networking KW - ANTS KW - application-specific routing KW - capsule architecture KW - capsule-based systems KW - computer crime KW - Computer network management KW - Computer networks KW - Computer science KW - Contracts KW - Electronic switching systems KW - INFORMATION SCIENCE KW - Internet KW - internetworking KW - network management KW - PLANet KW - Planets KW - programmability KW - programmable packets KW - Programming KW - Security KW - Standards development KW - telecommunication network routing KW - usability AB - Active networking adds programmability to the elements of the network, most aggressively by using programmable packets, or capsules. ANTS [22, 21] and PLANet [10, 8] are the most mature examples of capsule-based systems, both having been publicly available for several years. This paper presents our experience with these systems and the lessons they hold for the future of capsule-based active networking. The paper focuses on four key issues: flexibility, performance, security, and usability. We consider how ANTS and PLANet address these issues, noting that despite substantial surface differences, both systems identify similar key problems and use closely related solutions. Based on our experience with these systems we conclude that capsule-based systems can achieve useful levels of flexibility, performance, and usability. Many aspects of security can also be adequately addressed, but some important problems related to denial of service remain as open problems JA - DARPA Active NEtworks Conference and Exposition, 2002. Proceedings PB - IEEE SN - 0-7695-1564-9 M3 - 10.1109/DANCE.2002.1003481 ER - TY - CONF T1 - P5 : a protocol for scalable anonymous communication T2 - 2002 IEEE Symposium on Security and Privacy, 2002. Proceedings Y1 - 2002 A1 - Sherwood,R. A1 - Bhattacharjee, Bobby A1 - Srinivasan, Aravind KW - Broadcasting KW - communication efficiency KW - Computer science KW - cryptography KW - data privacy KW - Educational institutions KW - Internet KW - large anonymous groups KW - P5 protocol KW - packet-level simulations KW - Particle measurements KW - Peer to peer computing KW - peer-to-peer personal privacy protocol KW - privacy KW - Protocols KW - receiver anonymity KW - scalable anonymous communication KW - security of data KW - sender anonymity KW - sender-receiver anonymity KW - Size measurement KW - telecommunication security AB - We present a protocol for anonymous communication over the Internet. Our protocol, called P5 (peer-to-peer personal privacy protocol) provides sender-, receiver-, and sender-receiver anonymity. P5 is designed to be implemented over current Internet protocols, and does not require any special infrastructure support. A novel feature of P5 is that it allows individual participants to trade-off degree of anonymity for communication efficiency, and hence can be used to scalably implement large anonymous groups. We present a description of P5, an analysis of its anonymity and communication efficiency, and evaluate its performance using detailed packet-level simulations. JA - 2002 IEEE Symposium on Security and Privacy, 2002. Proceedings PB - IEEE SN - 0-7695-1543-6 M3 - 10.1109/SECPRI.2002.1004362 ER - TY - CONF T1 - Remote access to large spatial databases T2 - Proceedings of the 10th ACM international symposium on Advances in geographic information systems Y1 - 2002 A1 - Tanin,Egemen A1 - Brabec,František A1 - Samet, Hanan KW - client/server KW - GIS KW - Internet KW - peer-to-peer AB - Enterprises in the public and private sectors have been making their large spatial data archives available over the Internet. However, interactive work with such large volumes of online spatial data is a challenging task. We propose two efficient approaches to remote access to large spatial data. First, we introduce a client-server architecture where the work is distributed between the server and the individual clients for spatial query evaluation, data visualization, and data management. We enable the minimization of the requirements for system resources on the client side while maximizing system responsiveness as well as the number of connections one server can handle concurrently. Second, for prolonged periods of access to large online data, we introduce APPOINT (an Approach for Peer-to-Peer Offloading the INTernet). This is a centralized peer-to-peer approach that helps Internet users transfer large volumes of online data efficiently. In APPOINT, active clients of the client-server architecture act on the server's behalf and communicate with each other to decrease network latency, improve service bandwidth, and resolve server congestions. JA - Proceedings of the 10th ACM international symposium on Advances in geographic information systems T3 - GIS '02 PB - ACM CY - New York, NY, USA SN - 1-58113-591-2 UR - http://doi.acm.org/10.1145/585147.585150 M3 - 10.1145/585147.585150 ER - TY - JOUR T1 - Scalable secure group communication over IP multicast JF - Selected Areas in Communications, IEEE Journal on Y1 - 2002 A1 - Banerjee,S. A1 - Bhattacharjee, Bobby KW - access KW - algorithm; KW - authentication; KW - Bandwidth KW - communication; KW - CONTROL KW - costs; KW - cryptography; KW - dynamics; KW - group KW - group; KW - Internet KW - Internet-like KW - Internet; KW - IP KW - logarithmic KW - map; KW - membership; KW - message KW - Multicast KW - multicast; KW - network KW - overhead; KW - PROCESSING KW - protocol KW - protocols; KW - rekeying KW - requirements; KW - routers; KW - routing; KW - scalable KW - secure KW - security; KW - server; KW - simulation; KW - storage KW - Telecommunication KW - topologies; KW - Topology KW - topology; KW - transport KW - usage; AB - We introduce and analyze a scalable rekeying scheme for implementing secure group communications Internet protocol multicast. We show that our scheme incurs constant processing, message, and storage overhead for a rekey operation when a single member joins or leaves the group, and logarithmic overhead for bulk simultaneous changes to the group membership. These bounds hold even when group dynamics are not known a priori. Our rekeying algorithm requires a particular clustering of the members of the secure multicast group. We describe a protocol to achieve such clustering and show that it is feasible to efficiently cluster members over realistic Internet-like topologies. We evaluate the overhead of our own rekeying scheme and also of previously published schemes via simulation over an Internet topology map containing over 280 000 routers. Through analysis and detailed simulations, we show that this rekeying scheme performs better than previous schemes for a single change to group membership. Further, for bulk group changes, our algorithm outperforms all previously known schemes by several orders of magnitude in terms of actual bandwidth usage, processing costs, and storage requirements. VL - 20 SN - 0733-8716 CP - 8 M3 - 10.1109/JSAC.2002.803986 ER - TY - CONF T1 - Optimized seamless integration of biomolecular data T2 - Proceedings of the IEEE 2nd International Symposium on Bioinformatics and Bioengineering Conference, 2001 Y1 - 2001 A1 - Eckman,B. A A1 - Lacroix,Z. A1 - Raschid, Louiqa KW - analysis KW - Bioinformatics KW - biology computing KW - cost based knowledge KW - Costs KW - Data analysis KW - data mining KW - data visualisation KW - Data visualization KW - Data warehouses KW - decision support KW - digital library KW - Educational institutions KW - information resources KW - Internet KW - low cost query evaluation plans KW - Mediation KW - meta data KW - metadata KW - molecular biophysics KW - multiple local heterogeneous data sources KW - multiple remote heterogeneous data sources KW - optimized seamless biomolecular data integration KW - scientific discovery KW - scientific information systems KW - semantic knowledge KW - software libraries KW - visual databases KW - Visualization AB - Today, scientific data is inevitably digitized, stored in a variety of heterogeneous formats, and is accessible over the Internet. Scientists need to access an integrated view of multiple remote or local heterogeneous data sources. They then integrate the results of complex queries and apply further analysis and visualization to support the task of scientific discovery. Building a digital library for scientific discovery requires accessing and manipulating data extracted from flat files or databases, documents retrieved from the Web, as well as data that is locally materialized in warehouses or is generated by software. We consider several tasks to provide optimized and seamless integration of biomolecular data. Challenges to be addressed include capturing and representing source capabilities; developing a methodology to acquire and represent metadata about source contents and access costs; and decision support to select sources and capabilities using cost based and semantic knowledge, and generating low cost query evaluation plans JA - Proceedings of the IEEE 2nd International Symposium on Bioinformatics and Bioengineering Conference, 2001 PB - IEEE SN - 0-7695-1423-5 M3 - 10.1109/BIBE.2001.974408 ER - TY - CONF T1 - Practical programmable packets T2 - IEEE INFOCOM 2001. Twentieth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings Y1 - 2001 A1 - Moore,J. T A1 - Hicks, Michael W. A1 - Nettles,S. KW - active picket language KW - Application software KW - complier KW - Contracts KW - Data security KW - efficiency KW - Explosives KW - INFORMATION SCIENCE KW - Internet KW - IP KW - IP networks KW - low-level packet language KW - packet switching KW - performance KW - PLAN KW - practical programmable packets KW - program compilers KW - Protection KW - resource control KW - Resource management KW - safe and nimble active packets KW - Safety KW - Security KW - SNAP KW - software IP router KW - Software performance KW - telecommunication security KW - Transport protocols AB - We present SNAP (safe and nimble active packets), a new scheme for programmable (or active) packets centered around a new low-level packet language. Unlike previous active packet approaches, SNAP is practical: namely, adding significant flexibility over IP without compromising safety and security or efficiency. In this paper we show how to compile from the well-known active picket language PLAN to SNAP, showing that SNAP retains PLAN's flexibility; give proof sketches of its novel approach to resource control; and present experimental data showing SNAP attains performance very close to that of a software IP router JA - IEEE INFOCOM 2001. Twentieth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings PB - IEEE VL - 1 SN - 0-7803-7016-3 M3 - 10.1109/INFCOM.2001.916685 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 - Human-centered computing, online communities, and virtual environments JF - IEEE Computer Graphics and Applications Y1 - 1999 A1 - Brown,J. R A1 - van Dam,A. A1 - Earnshaw,R. A1 - Encarnacao,J. A1 - Guedj,R. A1 - Preece,J. A1 - Shneiderman, Ben A1 - Vince,J. KW - Books KW - Collaboration KW - Collaborative work KW - Conferences KW - EC/NSF joint Advanced Research Workshop KW - Feeds KW - Human computer interaction KW - human-centered computing KW - Internet KW - Joining materials KW - Laboratories KW - Online communities KW - Research initiatives KW - USA Councils KW - User interfaces KW - Virtual environment KW - virtual environments KW - Virtual reality AB - This report summarizes results of the first EC/NSF joint Advanced Research Workshop, which identified key research challenges and opportunities in information technology. The group agreed that the first joint research workshop should concentrate on the themes of human-centered computing and VEs. Human-centered computing is perceived as an area of strategic importance because of the move towards greater decentralization and decomposition in the location and provision of computation. The area of VEs is one where increased collaboration should speed progress in solving some of the more intractable problems in building effective applications VL - 19 SN - 0272-1716 CP - 6 M3 - 10.1109/38.799742 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 - Trust me, I'm accountable: trust and accountability online T2 - CHI '99 extended abstracts on Human factors in computing systems Y1 - 1999 A1 - Friedman,Batya A1 - Thomas,John C. A1 - Grudin,Jonathan A1 - Nass,Clifford A1 - Nissenbaum,Helen A1 - Schlager,Mark A1 - Shneiderman, Ben KW - accountability KW - anonymity KW - Communication KW - computers and society KW - ethics KW - Internet KW - media effects KW - privacy KW - Reciprocity KW - repute KW - social actors KW - social capital KW - social impacts KW - trust KW - value-sensitive design KW - wired world KW - WWW AB - We live in an increasingly wired world. According to Robert Putnam, people are spending less time in persistent personal face to face interactions and more time in pursuits such as watching TV and using the Internet. At the same time, independently measured "social capital" -- the extent to which we trust and work for a common good -- is declining. In this panel, we explore: the impacts of electronic media on trust and accountability; whether and how electronic media can be designed and used to increase deserved trust and accountability; the relationship between protecting privacy and increasing the efficacy of communication; and how people's tendency to treat computers as social actors impacts these issues. In brief, how can modern technology enhance humanity's humanity? JA - CHI '99 extended abstracts on Human factors in computing systems T3 - CHI EA '99 PB - ACM CY - New York, NY, USA SN - 1-58113-158-5 UR - http://doi.acm.org/10.1145/632716.632766 M3 - 10.1145/632716.632766 ER - TY - CONF T1 - Distance learning: is it the end of education as most of us know it? T2 - CHI 98 conference summary on Human factors in computing systems Y1 - 1998 A1 - Laurillard,Diana A1 - Preece,Jenny A1 - Shneiderman, Ben A1 - Neal,Lisa A1 - Wærn,Yvonne KW - distance learning KW - education KW - Internet KW - Web JA - CHI 98 conference summary on Human factors in computing systems T3 - CHI '98 PB - ACM CY - New York, NY, USA SN - 1-58113-028-7 UR - http://doi.acm.org/10.1145/286498.286542 M3 - 10.1145/286498.286542 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 - Wrapper generation for Web accessible data sources T2 - 3rd IFCIS International Conference on Cooperative Information Systems, 1998. Proceedings Y1 - 1998 A1 - Gruser,J. A1 - Raschid, Louiqa A1 - Vidal,M. E A1 - Bright,L. KW - application program interfaces KW - data mining KW - Databases KW - Educational institutions KW - Electrical capacitance tomography KW - HTML KW - HTML documents KW - Internet KW - Query processing KW - Read only memory KW - Search engines KW - Specification languages KW - Uniform resource locators KW - World Wide Web KW - wrapper generation toolkit KW - WWW AB - There is an increase in the number of data sources that can be queried across the WWW. Such sources typically support HTML forms-based interfaces and search engines query collections of suitably indexed data. The data is displayed via a browser: One drawback to these sources is that there is no standard programming interface suitable for applications to submit queries. Second, the output (answer to a query) is not well structured. Structured objects have to be extracted from the HTML documents which contain irrelevant data and which may be volatile. Third, domain knowledge about the data source is also embedded in HTML documents and must be extracted. To solve these problems, we present technology to define and (automatically) generate wrappers for Web accessible sources. Our contributions are as follows: (1) Defining a wrapper interface to specify the capability of Web accessible data sources. (2) Developing a wrapper generation toolkit of graphical interfaces and specification languages to specify the capability of sources and the functionality of the wrapper (3) Developing the technology to automatically generate a wrapper appropriate to the Web accessible source, from the specifications. JA - 3rd IFCIS International Conference on Cooperative Information Systems, 1998. Proceedings PB - IEEE SN - 0-8186-8380-5 M3 - 10.1109/COOPIS.1998.706180 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 - CONF T1 - User controlled overviews of an image library: a case study of the visible human T2 - Proceedings of the first ACM international conference on Digital libraries Y1 - 1996 A1 - North,Chris A1 - Shneiderman, Ben A1 - Plaisant, Catherine KW - Browsing KW - digital library KW - image database KW - information exploration KW - Information retrieval KW - Internet KW - medical image KW - remote access KW - user interface KW - Visualization KW - World-wide web JA - Proceedings of the first ACM international conference on Digital libraries T3 - DL '96 PB - ACM CY - New York, NY, USA SN - 0-89791-830-4 UR - http://doi.acm.org/10.1145/226931.226946 M3 - 10.1145/226931.226946 ER -