PLAN: a packet language for active networks - Hicks, Michael W.; Kakkar,Pankaj; Moore,Jonathan T.; Gunter,Carl A.; Nettles,Scott (SIGPLAN Not., 1998)
PLAN (Packet Language for Active Networks) is a new language for programs that form the packets of a programmable network. These programs replace the packet headers (which can be viewed as very rudimentary programs) used in current networks. As such, PLAN programs are lightweight and of restricted functionality. These limitations are mitigated by allowing PLAN code to call node-resident service routines written in other, more powerful languages. This two-level architecture, in which PLAN serves as a scripting or 'glue' language for more general services, is the primary contribution of this paper. We have successfully applied the PLAN programming environment to implement an IP-free internetwork.PLAN is based on the simply typed lambda calculus and provides a restricted set of primitives and datatypes. PLAN defines a special construct called a chunk used to describe the remote execution of PLAN programs on other nodes. Primitive operations on chunks are used to provide basic data transport in the network and to support layering of protocols. Remote execution can make debugging difficult, so PLAN provides strong static guarantees to the programmer, such as type safety. A more novel property aimed at protecting network availability is a guarantee that PLAN programs use a bounded amount of network resources.

The PLAN system for building Active Networks - Hicks, Michael W.; Kakkar,P.; Moore,J. T; Gunter,C. A; Alexander,D. S; Nettles,S. (University of Pennsylvania (February 27, 1998), 1998)

Spreading depression in focal ischemia: A computational study - Revett,K.; Ruppin,E.; Goodall,S.; Reggia, James A. (Journal of Cerebral Blood Flow & Metabolism, 1998)

The SwitchWare active network architecture - Alexander,D. S; Arbaugh, William A.; Hicks, Michael W.; Kakkar,P.; Keromytis,A. D; Moore,J. T; Gunter,C. A; Nettles,S. M; Smith,J. M (IEEE Network, 1998)
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
Keywords: active extensions; active packets; Authentication; Computer languages; Computer networks; cryptography; cryptography-based authentication; high-integrity base; integrity checking; IP networks; LAN interconnection; mobile programs; network operating systems; packet switching; programmable network infrastructure; programming languages; Protocols; Safety; safety requirements; scalability; secure active router infrastructure; Security; security requirements; services; strong type checking; Switches; SwitchWare active network architecture; telecommunication network routing; Tin; usability; verification techniques

The switchware active network implementation - Alexander,D. S; Hicks, Michael W.; Kakkar,P.; Keromytis,A. D; Shaw,M.; Moore,J. T; Gunter,C. A; Jim,T.; Nettles,S. M; Smith,J. M (The ML Workshop, International Conference on Functional Programming (ICFP), 1998)

A Thematic Hierarchy for Efficient Generation from Lexical-Conceptual Structure - Dorr, Bonnie J; Habash,Nizar; Traum,David (Machine Translation and the Information SoupMachine Translation and the Information Soup, 1998)
This paper describes an implemented algorithm for syntactic realization of a target-language sentence from an interlingual representation called Lexical Conceptual Structure (LCS). We provide a mapping between LCS thematic roles and Abstract Meaning Representation (AMR) relations; these relations serve as input to an off-the-shelf generator (Nitrogen). There are two contributions of this work: (1) the development of a thematic hierarchy that provides ordering information for realization of arguments in their surface positions; (2) the provision of a diagnostic tool for detecting inconsistencies in an existing online LCS-based lexicon that allows us to enhance principles for thematic-role assignment.

Three-Dimensional Hydrodynamic Modeling of MOSFET Devices - Kerr,Daniel C.; Goldsman,Neil; Mayergoyz, Issak D (VLSI Design, 1998)
The hydrodynamic (HD) model of semiconductor devices is solved numerically inthree-dimensions (3-D) for the MOSFET device. The numerical instabilities of the HD model are analyzed to develop a stable discretization. The formulation is stabilized by using a new, higher-order discretization for the relaxation-time approximation (RTA) term of the energy-balance (EB) equation. The developed formulation is used to model the MOSFET.

Trends in the Early Careers of Life Scientists - Tilghman,S; Astin,HS; Brinkley,W; Chilton,MD; Cummings, Michael P.; Ehrenberg,RG; Fox,MF; Glenn,K; Green,PJ; Hans,S; Kelman,A; LaPidus,J; et al. (National Academy Press, 1998)

Trends in the early careers of life scientists - Preface and executive summary - Tilghman,S; Astin,HS; Brinkley,W; Chilton,MD; Cummings, Michael P.; Ehrenberg,RG; Fox,MF; Glenn,K; Green,PJ; Hans,S; Kelman,A; LaPidus,J; et al. (Mol Biol Cell, 1998)

Updating Discourse Context with Active Logic - Gurney,John; Purang,Khemdut; Perlis, Don (Instititue for Advanced Computer Studies, Univ of Maryland, College Park, 1998)
In this paper we present our implementation of a system of active logicthat processes natural language discourses. We focus on problems that involve presupposition and the associated well-known problems of the projection of presupposition. We discuss Heim's largely successful theory of presupposition and point out certain limitations. We then use these observations to build our discourse processor based on active logic. Our main contributions are the handling of problems that go beyond the scope of Heim's theory , especially discourses the involve cancellation of presupposition. Ongoing work suggests that conversational implicature and the cancellation of implicature can also be treated by our methods. Key words: presupposition, discourse, con text, accommodation, active logic, implicature. (Also cross-referenced as UMIACS-TR-96-62)
Keywords: Technical Report

Utility elicitation as a classification problem - Chajewska,Urszula; Getoor, Lise; Norman,Joseph; Shahar,Yuval (Proceedings of the Fourteenth conference on Uncertainty in artificial intelligence, 1998)
We investigate the application of classification techniques to utility elicitation. In a decision problem, two sets of parameters must generally be elicited: the probabilities and the utilities. While the prior and conditional probabilities in the model do not change from user to user, the utility models do. Thus it is necessary to elicit a utility model separately for each new user. Elicitation is long and tedious, particularly if the outcome space is large and not decomposable. There are two common approaches to utility function elicitation. The first is to base the determination of the user's utility function solely on elicitation of qualitative preferences. The second makes assumptions about the form and decomposability of the utility function. Here we take a different approach: we attempt to identify the new user's utility function based on classification relative to a database of previously collected utility functions. We do this by identifying clusters of utility functions that minimize an appropriate distance measure. Having identified the clusters, we develop a classification scheme that requires many fewer and simpler assessments than full utility elicitation and is more robust than utility elicitation based solely on preferences. We have tested our algorithm on a small database of utility functions in a prenatal diagnosis domain and the results are quite promising.

Wrapper generation for Web accessible data sources - Gruser,J.; Raschid, Louiqa; Vidal,M. E; Bright,L. (3rd IFCIS International Conference on Cooperative Information Systems, 1998. Proceedings, 1998)
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.
Keywords: application program interfaces; data mining; Databases; Educational institutions; Electrical capacitance tomography; HTML; HTML documents; Internet; Query processing; Read only memory; Search engines; Specification languages; Uniform resource locators; World Wide Web; wrapper generation toolkit; WWW

2-D MOSFET modeling including surface effects and impact ionization by self-consistent solution of the Boltzmann, Poisson, and hole-continuity equations - Liang,Wenchao; Goldsman,N.; Mayergoyz, Issak D; Oldiges,P.J. (Electron Devices, IEEE Transactions on, 1997)
We present a new two-dimensional (2-D) MOSFET simulation method achieved by directly solving the Boltzmann transport equation for electrons, the hole-current continuity equation, and the Poisson equation self-consistently. The spherical harmonic method is used for the solution of the Boltzmann equation. The solution directly gives the electron distribution function, electrostatic potential, and the hole concentration for the entire 2-D MOSFET. Average quantities such as electron concentration and electron temperature are obtained directly from the integration of the distribution function. The collision integral is formulated to arbitrarily high spherical harmonic order, and new collision terms are included that incorporate effects of surface scattering and electron-hole pair recombination/generation. I-V characteristics, which agree with experiment, are calculated directly from the distribution function for an LDD submicron MOSFET. Electron-hole pair generation due to impact ionization is also included by direct application of the collision integral. The calculations are efficient enough for day-to-day engineering design on workstation-type computers
Keywords: 2D; characteristics; LDD; concentration; electron; concentration; hole-continuity; density; electron-hole; density; impact; device; distribution; effects; surface; equation; collision; equation; I-V; equation; MOSFET; electron; equations; impact; equations; semiconductor; function; electron; generation; electron-hole; harmonic; integral; electron; ionisation; integral; ionization; self-consistent; method; Boltzmann; method; surface; modeling; Boltzmann; models; surface; MOSFET; MOSFET; Poisson; pair; potential; hole; recombination; electrostatic; recombination; hole; scattering; scattering; two-dimensional; simulation; solution; spherical; submicron; temperature; electron-hole; transport

Automated manufacturability analysis: A survey - Gupta, Satyandra K.; Regli,William C.; Das,Diganta; Nau, Dana S. (Research in Engineering Design, 1997)
In the market-place of the 21st century, there is no place for traditional ‘over-the-wall’ communications between design and manufacturing. In order to ‘design it right the very first time’, designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems are emerging as one such tool — enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them.
Keywords: engineering

Better approximation guarantees for job-shop scheduling - Goldberg,Leslie Ann; Paterson,Mike; Srinivasan, Aravind; Sweedyk,Elizabeth (Proceedings of the eighth annual ACM-SIAM symposium on Discrete algorithms, 1997)

A computational model of acute focal cortical lesions - Goodall,S.; Reggia, James A.; Chen,Y.; Ruppin,E.; Whitney,C. (Stroke, 1997)

Effective redundant constraints for online scheduling - Getoor, Lise; Ottosson,G.; Fromherz,M.; Carlson,B. (PROCEEDINGS OF THE NATIONAL CONFERENCE ON ARTIFICIAL IN℡LIGENCE, 1997)
The use of heuristics as a means to improve constraint solverperformance has been researched widely. However, most work has been on problem-independent heuristics (e.g., vari- able and value ordering), and has focused on offline prob- lems (e.g., one-shot constraint satisfaction). In this paper, we present an online scheduling problem for which we are developing a real-time scheduling algorithm. While we can and do use generic heuristics in the scheduler, here we fo- cus on the use of domain-specific redundant constraints to ef- fectively approximate optimal offline solutions. We present a taxonomy of redundant domain constraints, and examine their impact on the effectiveness of the scheduler. We also describe several techniques for generating redundant con- straints, which can be applied to a large class of job shop scheduling problems.

Interpreting presuppositions using active logic: From contexts to utterances - Gurney,J.; Perlis, Don; Purang,K. (Computational Intelligence, 1997)

Local correspondence for detecting random forgeries - Guo,J. K; David Doermann; Rosenfeld, A. (Document Analysis and Recognition, 1997., Proceedings of the Fourth International Conference on, 1997)
Progress on the problem of signature verification has advanced more rapidly in online applications than offline applications, in part because information which can easily be recorded in online environments, such as pen position and velocity, is lost in static offline data. In offline applications, valuable information which can be used to discriminate between genuine and forged signatures is embedded at the stroke level. We present an approach to segmenting strokes into stylistically meaningful segments and establish a local correspondence between a questioned signature and a reference signature to enable the analysis and comparison of stroke features. Questioned signatures which do not conform to the reference signature are identified as random forgeries. Most simple forgeries can also be identified, as they do not conform to the reference signature's invariant properties such as connections between letters. Since we have access to both local and global information, our approach also shows promise for extension to the identification of skilled forgeries
Keywords: applications; online; applications; questioned; correspondence; offline; detection; reference; extraction; handwriting; features; stroke; forged; forgeries; random; forgeries; stroke; Forgery; level; stroke; meaningful; processing; properties; local; recognition; image; segmentation; stylistically; segmentation; word; segments; feature; signature; random; signature; signature; signatures; invariant; verification; skilled

MDL: a language and compiler for dynamic program instrumentation - Hollingsworth, Jeffrey K; Niam, O.; Miller, B. P; Zhichen Xu; Goncalves,M. J.R; Ling Zheng (, 1997 International Conference on Parallel Architectures and Compilation Techniques., 1997. Proceedings, 1997)
We use a form of dynamic code generation, called dynamic instrumentation, to collect data about the execution of an application program. Dynamic instrumentation allows us to instrument running programs to collect performance and other types of information. The instrumentation code is generated incrementally and can be inserted and removed at any time. Our instrumentation currently runs on the SPARC, PA-RISC, Power 2, Alpha, and x86 architectures. Specification of what data to collect are written in a specialized language called the Metric Description Language, that is part of the Paradyn Parallel Performance Tools. This language allows platform independent descriptions of how to collect performance data. It also provides a concise way to specify, how to constrain performance data to particular resources such as modules, procedures, nodes, files, or message channels (or combinations of these resources). We also describe the details of how we weave instrumentation into a running program
Keywords: Alpha architecture; application program; application program interfaces; Application software; compiler generators; Computer science; dynamic code generation; Dynamic compiler; dynamic program instrumentation; Educational institutions; files; instrumentation code; Instruments; MDL; measurement; message channels; Message passing; Metric Description Language; modules; nodes; Operating systems; optimising compilers; PA-RISC; Paradyn Parallel Performance Tools; Parallel architectures; parallel programming; performance data; platform independent descriptions; Power 2 architecture; Power generation; procedures; program debugging; Program processors; running programs; Runtime; software metrics; SPARC; Specification languages; x86 architecture

Mechanism design for intellectual property rights protection - Giridharan,P. S.; Srinivasan, Aravind (Proceedings of the eighteenth international conference on Information systems, 1997)

Regularization by Truncated Total Least Squares - Fierro,R. D.; Golub, G. H; Hansen,P. C.; O'Leary, Dianne P. (SIAM Journal on Scientific Computing, 1997)
The total least squares (TLS) method is a successful method for noise reduction in linear least squares problems in a number of applications. The TLS method is suited to problems in which both the coefficient matrix and the right-hand side are not precisely known. This paper focuses on the use of TLS for solving problems with very ill-conditioned coefficient matrices whose singular values decay gradually (so-called discrete ill-posed problems), where some regularization is necessary to stabilize the computed solution. We filter the solution by truncating the small singular values of the TLS matrix. We express our results in terms of the singular value decomposition (SVD) of the coefficient matrix rather than the augmented matrix. This leads to insight into the filtering properties of the truncated TLS method as compared to regularized least squares solutions. In addition, we propose and test an iterative algorithm based on Lanczos bidiagonalization for computing truncated TLS solutions.
Keywords: bidiagonalization; discrete ill-posed problems; regularization; total least squares

Semantic query optimization for object databases - Grant,J.; Gryz,J.; Minker, Jack; Raschid, Louiqa (Data Engineering, 1997. Proceedings. 13th International Conference on, 1997)
Presents a technique for semantic query optimization (SQO) for object databases. We use the ODMG-93 (Object Data Management Group) standard ODL (Object Database Language) and OQL (Object Query Language) languages. The ODL object schema and the OQL object query are translated into a DATALOG representation. Semantic knowledge about the object model and the particular application is expressed as integrity constraints. This is an extension of the ODMG-93 standard. SQO is performed in the DATALOG representation, and an equivalent logic query and (subsequently) an equivalent OQL object query are obtained. SQO is based on the residue technique of Chakravarthy et al. (1990). We show that our technique generalizes previous research on SQO for object databases. It can be applied to queries with structure constructors and method application. It utilizes integrity constraints about keys, methods and knowledge of access support relations, to produce equivalent queries, which may have more efficient evaluation plans
Keywords: application; object; constraints; keys; method; constructors; DATALOG; data; databases; object-oriented; databases; query; Datalog; Evaluation; integrity; data; languages; query; Logic; object; optimization; structure; plans; residue; processing; software; query; query; access; query; integrity; relations; equivalent; representation; ODL; schema; ODMG-93; standard; OQL; standards; structures; object-oriented; Support; technique; semantic

Semantic query optimization for object databases - Grant,J.; Gryz,J.; Minker, Jack; Raschid, Louiqa (Data Engineering, 1997. Proceedings. 13th International Conference on, 1997)

Symbolic model checking of infinite state systems using Presburger arithmetic - Bultan,T.; Gerber,R.; Pugh, William (Computer Aided Verification, 1997)

Towards multiprocessor feature recognition - Regli,William C.; Gupta, Satyandra K.; Nau, Dana S. (Computer-Aided Design, 1997)
The availability of low-cost computational power is enabling the development of increasingly sophisticated cad software. Automation of design and manufacturing activities poses many difficult computational problems—significant among them is how to develop interactive systems that enable designers to explore and experiment with alternative ideas. As more downstream manufacturing activities are considered during the design phase, computational costs become problematic. Creating working software-based solutions requires a sophisticated allocation of computational resources in order to perform realistic design analyses and generate feedback. This paper presents our initial efforts to employ multiprocessor algorithms to recognize machining features from solid models of parts with large numbers of features and many geometric and topological entities. Our goal is to outline how improvements in computation time can be obtained by migrating existing software tools to multiprocessor architectures. An implementation of our approach is discussed.
Keywords: Distributed computing; feature recognition; feature-based modelling; multiprocessor solid modelling

Using manufacturing planning to generate manufacturability feedback - Gupta,S.K. (Journal of Mechanical Design, 1997)

A zooming web browser - Bederson, Benjamin B.; Hollan,J.D.; Stewart,J.; Rogers,D.; Druin, Allison; Vick,D.; Ring,L.; Grose,E.; Forsythe,C. (Human Factors in Web Development, 1997)

Disjunctive deductive databases: Semantics, updates and architecture - Fernandez,J. A.; Gryz,J.; Minker, Jack (Proceedings of the 4th Bar-Ilan Symposium on Foundations of AI, 1996)
The basic assumption in relational and deductive databases is that there are no gaps in our knowledge. That is, the database cannot store data that contain null values or data that is indefinite. In practical situations knowledge is not precise, and there are gaps in our knowledge. These gaps may be due to null values in the data, may arise when we combine several databases that lead to inconsistent theories, or may occur because information is indefinite in nature, such as in military or medical applications. In this paper we describe semantics for disjunctive deductive databases that extend the work in deductive databases, solve the view update problem, and permit indefinite data to be represented efficiently. Hierarchic, stratified, and normal stable models of disjunctive databases are described. An architecture is proposed for a disjunctive deductive database system and a class of theories for which the architecture will be effective is discussed.

Efficient distribution analysis via graph contraction - Sheffler,T.; Schreiber,R.; Pugh, William; Gilbert,J.; Chatterjee,S. (Languages and Compilers for Parallel Computing, 1996)

The empirical investigation of Perspective-Based Reading - Basili, Victor R.; Green,Scott; Laitenberger,Oliver; Lanubile,Filippo; Shull, Forrest; Sørumgård,Sivert; Zelkowitz, Marvin V (Empirical Software Engineering, 1996)
We consider reading techniques a fundamental means of achieving high quality software. Due to the lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with a family of reading techniques known as Perspective-Based Reading (PBR), and its application to requirements documents. The goal of PBR is to provide operational scenarios where members of a review team read a document from a particular perspective, e.g., tester, developer, user. Our assumption is that the combination of different perspectives provides better coverage of the document, i.e., uncovers a wider range of defects, than the same number of readers using their usual technique.
Keywords: Computer; Science

Generating redesign suggestions to reduce setup cost: a step towards automated redesign - Das,Diganta; Gupta, Satyandra K.; Nau, Dana S. (Computer-Aided Design, 1996)
All mechanical designs pass through a series of formal and informal redesign steps, involving the analysis of functionality, manufacturability, cost and other life-cycle factors. The speed and efficacy of these steps has a major influence on the lead time of the product from conceptualization to launching. In this paper we propose a methodology for automatically generating redesign suggestions for reducing setup costs for machined parts.Given an interpretation of the design as a collection of machinable features, our approach is to generate alternate machining features by making geometric changes to the original features, and add them to the feature set of the original part to create an extended feature set. The designer may provide restrictions on the design indicating the type and extent of modifications allowed on certain faces and volumes, in which case all redesign suggestions generated by our approach honour those restrictions. By taking combinations of features from the extended feature set generated above, we can generate modified versions of the original design that still satisfy the designer's intent. By considering precedence constraints, we can estimate the setup time that will be required for each design. Any modified design whose setup time is less than that of the original design can be presented to the designer as a possible way to modify the original design.

A high performance image database system for remotely sensed imagery - Shock,C.; Chang,C.; Davis, Larry S.; Goward,S.; Saltz, J.; Sussman, Alan (Euro-Par'96 Parallel Processing, 1996)

Learning activation rules for associative networks - Reggia, James A.; Grundstrom,E.; Berndt,R. S (Neural Networks, 1996., IEEE International Conference on, 1996)

Learning Activation Rules Rather Than Connection Weights - Grundstrom,E. L; Reggia, James A. (International journal of neural systems, 1996)

Model theoretic approach to view updates in deductive databases - Fernandez,J. A.; Grant,J.; Minker, Jack (Journal of Automated Reasoning, 1996)
The view update problem for deductive databases has been defined as the problem of accomplishing the update of an intensional predicate by modifying appropriately the extensional database. A previous paper by Grant, Horty, Lobo, and Minker developed algorithms for the insertion and the deletion of an intensional predicate in certain important classes of stratified disjunctive deductive databases. This paper introduces a model theoretic approach which encompasses a wide class of Herbrand semantics, including the perfect model and stable model semantics, for disjunctive databases including negation. This generalizes the earlier results: now the intensional database may contain disjunctive and denial rules, and the database may be required to satisfy integrity constraints. As in the previous paper, the algorithms are proved to be correct and best according to the criterion of causing minimal change to the database, where the first priority is to minimize deletions.

Semantic query optimization for bottom-up evaluation - Godfrey,P.; Gryz,J.; Minker, Jack (Foundations of Intelligent Systems, 1996)
Semantic query optimization uses semantic knowledge in databases (represented in the form of integrity constraints) to rewrite queries and logic programs to achieve efficient query evaluation. Much work has been done to develop various techniques for optimization. Most of it, however, is applicable to top-down query evaluation strategies. Moreover, little attention has been paid to the cost of the optimization. We address the issue of semantic query optimization for bottom-up query evaluation strategies with an emphasis on overall efficiency. We focus on a single optimization technique, join elimination. We discuss factors that influence the cost of semantic optimization, and present two different abstract algorithms for optimization. The first pre-processes a query statically before it is evaluated; the second combines query evaluation with semantic optimization using heuristics to achieve the largest possible savings.

SEROS – A SELF-ROUTING OPTICAL ATM SWITCH - Guizani,Mohsen; Memon, Atif M. (International Journal of Communication Systems, 1996)
A fault-tolerant high-performance SElf-Routing 2 × 2 Optical ATM Switch (SEROS) is proposed. The switch is designed using all-optical components which allows the exploitation of spatial parallelism. SEROS can be used with any multistage interconnection network such as Omega, Banyan, Shuffle or Benes. For the purpose of this study, SEROS has been incorporated into a generic self-routing multistage interconnection network that uses 2 × 2 switches and is not fault tolerant. Reliability analysis is carried out and the results are compared with two major fault-tolerant networks. They show that without redundant switches, better network survivability is achieved. All the switches in the network are 2 × 2, making it easier to mass produce.
Keywords: 2 × 2 ATM switch; fault-tolerant; MINs; photonic switching network; reliability; self-routing

Space/time trade-offs for associative memory - GROVE,A. J; Jacobs, David W. (Pattern Recognition, 1996., Proceedings of the 13th International Conference on, 1996)
In any storage scheme, there is some trade-off between the space used (size of memory) and access time. However, the nature of this trade-off seems to depend on more than just what is being stored-it also depends the types of queries we consider. We justify this claim by considering a particular memory model and contrast recognition (membership queries) with associative recall. We show that the latter task can require exponentially larger memories even when identical information is stored
Keywords: access; matching; set; memory; associative; nets; pattern; processing; content-addressable; query; memory; recall; membership; scheme; associative; space; set; storage; neural; theory; theory; storage; time; associative

Automated Manufacturability Analysis: A Survey - Das,Diganta; Gupta, Satyandra K.; Regli,W. C.; Nau, Dana S. (Institute for Systems Research, University of Maryland, College Park, 1995)
In the marketplace of the 21st century, there is no place for traditional ``over-the-wall'' communications between design and manufacturing. In order to ``design it right the very first time,'' designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems are emerging as one such tool---enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them. In this paper, we provide a survey of current state of the art in automated manufacturability analysis. We present the historical context in which this area has emerged and outline characteristics to compare and classify various systems. We describe the two dominant approaches to automated manufacturability analysis and overview representative systems based on their application domain. We describe support tools that enhance the effectiveness of manufacturability analysis systems. Finally, we attempt to expose some of the existing research challenges and future directions.
Keywords: manufacturability; Manufacturing; Solid modeling; Systems Integration Methodology

Automated Manufacturability Analysis of Machined Parts - Gupta, Satyandra K. (UNIVERSITY OF MARYLAND, COLLEGE PARK, 1995)
Because of pressing demands to reduce lead time and product cost, increasing research attention is being given to integration of engineering design and manufacturing. In this thesis, a systematic approach has been developed for computer-aided manufacturability analysis of machined parts. This approach can be used during design stages to improve the product quality from the manufacturing point of view. Evaluating the manufacturability of a proposed design involves determining whether or not it is manufacturable with a given set of manufacturing operations - and if so, then finding the associated manufacturing efficiency. In this research, the design is represented as a solid model. The tolerance and surface finish information is represented as attributes of various faces of the solid model. Machining features are used to model the available machining operations Since there can be several different ways to manufacture a proposed design, this requires considering alternative ways to manufacture it, in order to determine which one best meets the design and manufacturing objectives. The approach developed in this thesis is based on the systematic exploration of various machining plans. The first step is to identify all machining features which can potentially be used to machine the given design. Using these features, different machining plans are generated. Each time a new plan generated, it is examined to find whether it can produce the desired design tolerances. If a plan is found to be capable of meeting the tolerance specifications, then its rating is computed. If no machining plan can be found that is capable of producing the design, then the design cannot be machined using the given set of machining operations; otherwise, the manufacturability rating of the design is computed. Since various alternative ways of machining the part are considered in this approach, the conclusions about the manufacturability are more realistic compared to the approach where just one alternative is considered. It is anticipated that this research will help in speeding up the evaluation of new product designs in order to decide how or whether to manufacture them. Such a capability will be useful in responding quickly to changing demands and opportunities in the marketplace.
Keywords: Automation; computer aided manufacturing; computer integrated manufacturing; Feature extraction; flexible manufacturing; manufacturability; Manufacturing; Solid modeling

The COLLAGE/KHOROS link: Planning for image processing tasks - Lansky,A.; Friedman,M.; Getoor, Lise; Schmidler,S.; Short Jr,N. (Integrated Planning Applications, 1995)

Current Trends and Future Challenges in Automated Manufacturability Analysis - Gupta, Satyandra K.; Das,Diganta; Regli,W. C.; Nau, Dana S. (Institute for Systems Research, University of Maryland, College Park, 1995)
In the marketplace of the 21st century, there is no place for traditional communications between design and manufacturing. In order to ``design it right the first time,'' designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems are emerging as one such tool---enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them. In this paper, we survey of current state of the art in automated manufacturability analysis. We describe the two dominant approaches to automated manufacturability analysis and overview representative systems based on their application domain. Finally, we attempt to expose some of the existing research challenges and future directions.
Keywords: computer integrated manufacturing; manufacturability; Manufacturing; Solid modeling; Systems Integration Methodology

Efficient on-the-fly model checking for CTL - Bhat,G.; Cleaveland, Rance; Grumberg,O. (, Tenth Annual IEEE Symposium on Logic in Computer Science, 1995. LICS '95. Proceedings, 1995)
This paper gives an on-the-fly algorithm for determining whether a finite-state system satisfies a formula in the temporal logic CTL. The time complexity of our algorithm matches that of the best existing “global algorithm” for model checking in this logic, and it performs as well as the best known global algorithms for the sublogics CTL and LTL. In contrast with these approaches, however, our routine constructs the state space of the system under consideration in a need-driven fashion and will therefore perform better in practice
Keywords: Algorithm design and analysis; Automata; computational complexity; Computer science; CTL; Encoding; finite automata; finite-state system; global algorithm; Logic; LTL; on-the-fly model checking; Performance analysis; Safety; State-space methods; sublogic; temporal logic; time complexity

Estimation of setup time for machined parts: accounting for work-holding constraints using a vise - Das,D.; Gupta,S.K.; Nau, Dana S. (COMPUTERS IN ENGINEERING, 1995)
For machined parts, setup time is a major component ofthe total time required to manufacture a machined part from a stock. If the number of setups and hence setup time can be reduced, this will not only decrease the manufacturing time, but will also ensure better machining accuracy, require fewer work-holding devices and increase machine usage time. To achieve any improvement in setup time, rst we need to estimate the setup time accurately. In this paper we pro- pose a methodology to estimate the setup time for machin- ing prismatic parts in a three axis vertical machining center. We concurrently consider three major factors for estimating the number of setups, namely|the precedence constraints among machining operations, the feasibility of work holding using vise clamping, and the availability of datum faces for locating the workpiece on the machine table during machin- ing on a 3 axis vertical machining center.

Evaluation and selection of biases in machine learning - Gordon,Diana F.; desJardins, Marie (Machine Learning, 1995)
In this introduction, we define the term bias as it is used in machine learning systems. We motivate the importance of automated methods for evaluating and selecting biases using a framework of bias selection as search in bias and meta-bias spaces. Recent research in the field of machine learning bias is summarized.

Explicitly Biased Generalization - Gordon,D.; Perlis, Don (Goal-Driven Learning, 1995)

Extracting alternative machining features: An algorithmic approach - Regli,William C.; Gupta, Satyandra K.; Nau, Dana S. (Research in Engineering Design, 1995)
Automated recognition of features from CAD models has been attempted for a wide range of application domains. In this article we address the problem of representing and recognizing a complete class of features in alternative interpretation for a given design.
Keywords: engineering

Interactive feature recognition using multi-processor methods - Regli,W. C.; Gupta,S.K.; Nau, Dana S. (1995)

Land cover dynamics investigation using parallel computers - Liang, S.; Davis, Larry S.; Townshend,J.; Chellapa, Rama; DeFries, R.; Dubayah, R.; Goward,S.; JaJa, Joseph F.; Krishnamachar, S.; Roussopoulos, Nick; Saltz, J.; Samet, Hanan; et al. (Geoscience and Remote Sensing Symposium, 1995. IGARSS '95. 'Quantitative Remote Sensing for Science and Applications', International, 1995)
A comprehensive and highly interdisciplinary research program is being carried out to investigate global land cover dynamics in heterogeneous parallel computing environments. Some of the problems are addressed including atmospheric correction, mixture modeling, image classifications by Markovian random fields and by segmentation, global image/map databases, object oriented parallel programming and parallel/IO. During the initial two years project, significant progress has been made in all of these areas
Keywords: geographic information system; geophysical measurement technique; geophysics computing; image classification; image map database; image segmentation; land cover dynamics; land surface; mixture modeling; object oriented programming; optical imaging; para; GIS; IR imaging; Markovian random fields; atmospheric correction

Localization of Sequences Required for Size-specific Splicing of a SmallDrosophilaIntronin Vitro - Guo,Ming; Mount, Stephen M. (Journal of Molecular Biology, 1995)
Many introns inDrosophilaand other invertebrates are less than 80 nucleotides in length, too small to be recognized by the vertebrate splicing machinery. Comparison of nuclear splicing extracts from human HeLa andDrosophilaKc cells has revealed species-specificity, consistent with the observed size differences. Here we present additional results with the 68 nucleotide fifth intron of theDrosophilamyosin heavy chain gene. As observed with the 74 nucleotide second intron of theDrosophilawhite gene, the wild-type myosin intron is accurately spliced in a homologous extract, and increasing the size by 16 nucleotides both eliminates splicing in theDrosophilaextract and allows accurate splicing in the human extract. In contrast to previous results, however, an upstream cryptic 5′ splice site is activated when the wild-type myosin intron is tested in a human HeLa cell nuclear extract, resulting in the removal of 98 nucleotide intron.The size dependence of splicing inDrosophilaextracts is also intron-specific; we noted that a naturally larger (150 nucleotide) intron from theftzgene is efficiently spliced in Kc cell extracts that do not splice enlarged introns (of 84, 90, 150 or 350 nucleotides) derived from the 74 nucleotidewhiteintron. Here, we have exploited that observation, using a series of hybrid introns to show that a region of 46 nucleotides at the 3′ end of thewhiteintron is sufficient to confer the species-specific size effect. At least two sequence elements within this region, yet distinct from previously described branchpoint and pyrimidine tract signals, are required for efficient splicing of small splicing of small hybrid intronsin vitro.
Keywords: Drosophila; pre-mRNA splicing; intron size; species specificity; in vitrosplicing

Manufacturing feature instances: which ones to recognize? - Gupta, Satyandra K.; Regli,William C.; Nau, Dana S. (ACM, 1995)

Next generation network management technology - Baras,John S; Atallah,George C; Ball,Mike; Goli,Shravan; Karne,Ramesh K; Kelley,Steve; Kumar,Harsha; Plaisant, Catherine; Roussopoulos, Nick; Schneiderman,Ben; Srinivasarao,Mulugu; Stathatos,Kosta; et al. (AIP Conference Proceedings, 1995)
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

Parametric dispatching of hard real-time tasks - Gerber,R.; Pugh, William; Saksena,M. (IEEE Transactions on ComputersIEEE Trans. Comput., 1995)

Polynomial-time algorithm for computing translocation distance between genomes - Hannenhalli, Sridhar (Combinatorial Pattern MatchingCombinatorial Pattern Matching, 1995)
With the advent of large-scale DNA physical mapping and sequencing, studies of genome rearrangements are becoming increasingly important in evolutionary molecular biology. From a computational perspective, study of evolution based on rearrangements leads to rearrangement distance problem, i.e., computing the minimum number of rearrangement events required to transform one genome into another. Different types of rearrangement events give rise to a spectrum of interesting combinatorial problems. The complexity of most of these problems is unknown. Multichromosomal genomes frequently evolve by a rearrangement event called translocation which exchanges genetic material between different chromosomes. In this paper we study the translocation distance problem, modeling evolution of genomes evolving by translocations. Translocation distance problem was recently studied for the first time by Kececioglu and Ravi, who gave a 2-approximation algorithm for computing translocation distance. In this paper we prove a duality theorem leading to a polynomial algorithm for computing translocation distance for the case when the orientation of the genes are known. This leads to an algorithm generating a most parsimonious (shortest) scenario, transforming one genome into another by translocations.

Representing a student’s learning states and transitions - Gurer,D.; desJardins, Marie; Schlager,M. (American Association of Artificial Intelligence Spring Symposium on Representing Mental States and Mechanisms, 1995)
We describe an ongoing project to develop an adaptive training system (ATS) that dynamically models a student’s learning processes and can provide specialized tutoring adapted to a student’s knowledge state and learning style. The student modeling component of the ATS, ML-Modeler, uses machine learning (ML) techniques to emulate the student’s novice-toexpert transition. ML-Modeler infers which learning methods the student has used to reach the current knowledge state by comparing the student’s solution trace to an expert solution and generating plausible hypotheses about what misconceptions and errors the student has made. A case-based approach is used to generate hypotheses through incorrectly applying analogy, overgeneralization, and overspecialization. The student and expert models use a network-based representation that includes abstract concepts and relationships as well as strategies for problem solving. Fuzzy methods are used to represent the uncertainty in the student model. This paper describes the design of the ATS and ML-Modeler, and gives a detailed example of how the system would model and tutor the student in a typical session. The domain we use for this example is high-school level chemistry.

Scope and abstraction: Two criteria for localized planning - Lansky,A. L; Getoor, Lise (INTERNATIONAL JOINT CONFERENCE ON ARTIFICIAL INTELLIGENCE, 1995)
Localization is a general-purpose representational technique for partitioning a problem intosubproblems. A localized problem-solver searches several smaller search spaces, one for each subproblem. Unlike most methods of partitioning, however, localization allows for subprob- lems that overlap i.e. multiple search spaces may be involved in constructing shared pieces of the overall plan. In this paper we focus on two criteria for forming localizations: scope and abstraction. We describe a method for automatically generating such localizations and provide empirical results that contrast their use in an o ce-building construction domain.

Selecting Tense, Aspect, and Connecting Words In Language Generation - Dorr, Bonnie J; Gaasterland,Terry (In Proceedings of IJCAI-95, 1995)
Generating language that reflects the temporal organization of represented knowledge requires a language generation model that integrates contemporary theories of tense and aspect, temporal representations, and methods to plan text. This paper presents a model that produces complex sentences that reflect temporal relations present in underlying temporal concepts. The main result of this work is the successful application of constrained linguistic theories of tense and aspect to a generator which produces meaningful event combinations and selects appropriate connecting words that relate them. 1 Introduction Reasoning about temporal knowledge and formulating answers to questions that involve time necessitate the presentation of temporal information to users. One approach is to incorporate the temporal information directly into natural language paraphrases of the represented knowledge. This requires a method to plan language that contains not only tense selections, but aspect selections...

Systematic approach to analysing the manufacturability of machined parts - Gupta, Satyandra K.; Nau, Dana S. (Computer-Aided Design, 1995)
The ability to quickly introduce new quality products is a decisive factor in capturing market share. Because of pressing demands to reduce leadtimes, analysing the manufacturability of the proposed design has become an important step in the design stage. The paper presents an approach to analysing the manufacturability of machined parts.Evaluating the manufacturability of a proposed design involves determining whether or not it is manufacturable with a given set of manufacturing operations, and, if it is, finding the associated manufacturing efficiency. Since there can be several different ways to manufacture a proposed design, this requires that different ways to manufacture it be considered, in order to determine which one best meets the design and manufacturing objectives. The first step in the approach is to identify all the machining operations which can potentially be used to create the given design. Using these operations, different operation plans are generated for machining the part. Each time a new operation plan is generated, the user examines whether it can produce the desired shape and tolerances, and calculates its manufacturability rating. If no operation plan can be found that is capable of producing the design, then the given design is considered unmachinable; otherwise, the manufacturability rating for the design is the rating of the best operation plan. The authors expect that, by providing feedback about possible problems with the design, the work described in the paper will help in speeding up the evaluation of new product designs so that it can be decided how or whether to manufacture them. Such a capability will be useful in responding quickly to changing demands and opportunities in the marketplace.
Keywords: computer-aided manufacturability analysis; design for manufacturability; feature-based models

AAAI 1994 Spring Symposium Series Reports - Woods,William; Uckun,Sendar; Kohane,Isaac; Bates,Joseph; Hulthage,Ingemar; Gasser,Les; Hanks,Steve; Gini,Maria; Ram,Ashwin; desJardins, Marie; Johnson,Peter; Etzioni,Oren; et al. (AI Magazine, 1994)

An Application of Distributed Solid Modeling: Feature Recognition - Regli,W. C.; Gupta, Satyandra K.; Nau, Dana S. (Institute for Systems Research, University of Maryland, College Park, 1994)
The availability of low-cost computational power is a driving force behind the growing sophistication of CAD software. Tools designed to reduce time-consuming build-test-redesign iterations are essential for increasing engineering quality and productivity. However, automation of the design process poses many difficult computational problems. As more downstream engineering activities are being considered during the design phase, guaranteeing reasonable response times within design systems becomes problematic. Design is an interactive process and speed is a critical factor in systems that enable designers to explore and experiment with alternative ideas during the design phase. Achieving interactivity requires an increasingly sophisticated allocation of computational resources in order to perform realistic design analyses and generate feedback in real time. This paper presents our initial efforts to develop techniques to apply distributed algorithms to the problem of recognizing machining features from solid models. Existing work on recognition of features has focused exclusively on serial computer architectures. Our objective is to show that distributed algorithms can be employed on realistic parts with large numbers of features and many geometric and topological entities to obtain significant improvements in computation time using existing hardware and software tools. Migrating solid modeling applications toward a distributed computing frame-work enables interconnection of many of the autonomous and geographically diverse software tools used in the modern manufacturing enterprise. This has been implemented on a network of SUN workstations using the ACIS solid modeler and the NIH C++ class library; inter-processor communication is handled with TCP/IP- based network communication tools.
Keywords: Distributed computing; feature recognition; feature- based modeling; multiprocessor solid modeling; Systems Integration Methodology

Building MRSEV models for CAM applications - Gupta, Satyandra K.; Kramer,Thomas R.; Nau, Dana S.; Regli,William C.; Zhang,Guangming (Advances in Engineering Software, 1994)
In integrating CAD and CAM applications, one major problem is how to interpret CAD information in a manner that makes sense for CAM. The goal is to develop a general approach that can be used with a variety of CAD and CAM applications for the manufacture of machined parts.In particular, a methodology is presented for taking a CAD model, extracting alternative interpretations of the model as collections of MRSEVs (material removal shape element volumes, a STEP-based library of machining features), and evaluating these interpretations to determine which one is optimal. The evaluation criteria may be defined by the user, in order to select the best interpretation for the particular application at hand.
Keywords: CAD/CAM integration; design critiquing; feature recognition

Calculation of head sensitivity function from 3-D magnetic fields - Burke,E.R.; Gomez,R.D.; Madabhushi,R.; Mayergoyz, Issak D (Magnetics, IEEE Transactions on, 1994)
A head sensitivity function is calculated using 3-D magnetic fields. The 3-D magnetic fields are calculated for recorded tracks with finite widths. The magnetization in the medium is expressed in 2-D Fourier series in the plane of the film and is assumed uniform through the thickness of the film. The reproduce head is idealized. These techniques are applied to data found in the literature for very narrow tracks ( 0.5 mu;m). A surprising amount of the experimental data can be explained by the finite width of the tracks. The fine structure of the measurements can then be isolated and attributed to the particular features of the individual heads
Keywords: 3-D; fields; finite; fields; magnetic; function; magnetization; recorded; head; very; heads; magnetisation; sensitivity; magnetic; narrow; Sensitivity; series; magnetic; tracks; Fourier; tracks; reproduce; widths; head

Calibrating, Counting, Grounding, Grouping - Elgot-drapkin,J.; Gordon,D.; Kraus,S.; Miller,M.; Nirkhe,M.; Perlis, Don (Association for the Advancement of Artificial Intelligence, 1994)

On the convergence of line iterative methods for cyclically reduced non-symmetrizable linear systems - Elman, Howard; Golub, G. H; Starke, G. (Numerische Mathematik, 1994)

Design for manufacture in multi-enterprise partnerships: current status and future directions - Nau, Dana S.; Ball,M. O; Gupta,S.K.; Minis,I. E.; Zhang, G. (1994)
To pursue market and technology opportunities effectively, US commercial and defense industries will be relying increasingly on multi-enterprise partnerships. Horizontal partnering combines the strengths of multiple firms in product design, manufacture, after sales support and customer service, in order to launch superior products in the global market. To support effective partnering, new approaches will be needed for integrating the activities of design, planning, and production. It is important to address both the fundamental modeling of design, process planning, and production planning in ways that account for the capabilities of potential manufacturing partners, and the development of optimization procedures to address the underlying decision problems. This paper elaborates on these issues and discusses approaches for addressing them.

Feature Recognition for Manufacturability Analysis - Regli,W. C.; Gupta, Satyandra K.; Nau, Dana S. (Institute for Systems Research, University of Maryland, College Park, 1994)
While automated recognition of features has been attempted for a wide range of applications, no single existing approach possesses the functionality required to perform manufacturability analysis. In this paper, we present a methodology for taking a CAD model and extracting a set of machinable features suitable for generating all alternative interpretations of the model as collections of MRSEVs (Material Removal Shape Element Volumes, a STEP-based library of machining, features). This set of MRSEVs is to be employed for manufacturability analysis. The algorithm handles a variety of features including those describing holes, pockets, slots, and chamfering and filleting operations. In addition, it considers elementary accessibility constraints for these features and is provably complete over a, significant class of machinable parts the features describe. Further, the approach has low-order polynomial-time worst-case complexity.
Keywords: algorithms; Automation; COMPUTER AIDED DESIGN; computer aided manufacturing; computer integrated manufacturing; Feature extraction; manufacturability; Manufacturing; Solid modeling; Systems Integration

From syntactic encodings to thematic roles: Building lexical entries for interlingual MT - Dorr, Bonnie J; Garman,Joseph; Weinberg, Amy (Machine Translation, 1994)
Our goal is to construct large-scale lexicons for interlingual MT of English, Arabic, Korean, and Spanish. We describe techniques that predict salient linguistic features of a non-English word using the features of its English gloss (i.e., translation) in a bilingual dictionary. While not exact, owing to inexact glosses and language-to-language variations, these techniques can augment an existing dictionary with reasonable accuracy, thus saving significant time. We have conducted two experiments that demonstrate the value of these techniques. The first tested the feasibility of building a database of thematic grids for over 6500 Arabic verbs based on a mapping between English glosses and the syntactic codes in Longman's Dictionary of Contemporary English (LDOCE) (Procter, 1978). We show that it is more efficient and less error-prone to hand-verify the automatically constructed grids than it would be to build the thematic grids by hand from scratch. The second experiment tested the automatic classification of verbs into a richer semantic typology based on (Levin, 1993), from which we can derive a more refined set of thematic grids. In this second experiment, we show that a brute-force, non-robust technique provides 72% accuracy for semantic classification of LDOCE verbs; we then show that it is possible to approach this yield with a more robust technique based on fine-tuned statistical correlations. We further suggest the possibility of raising this yield by taking into account linguistic factors such as polysemy and positive and negative constraints on the syntax-semantics relation. We conclude that, while human intervention will always be necessary for the construction of a semantic classification from LDOCE, such intervention is significantly minimized as more knowledge about the syntax-semantics relation is introduced.
Keywords: humanities; Social Sciences and Law

Inexact and Preconditioned Uzawa Algorithms for Saddle Point Problems - Elman, Howard; Golub, Gene H. (SIAM Journal on Numerical Analysis, 1994)
Variants of the Uzawa algorithm for solving symmetric indefinite linear systems are developed and analyzed. Each step of this algorithm requires the solution of a symmetric positive-definite system of linear equations. It is shown that if this computation is replaced by an approximate solution produced by an arbitrary iterative method, then with relatively modest requirements on the accuracy of the approximate solution, the resulting inexact Uzawa algorithm is convergent, with a convergence rate close to that of the exact algorithm. In addition, it is shown that preconditioning can be used to improve performance. The analysis is illustrated and supplemented using several examples derived from mixed finite element discretization of the Stokes equations.

Integrating DFM with CAD through Design Critiquing - Gupta, Satyandra K.; Regli,William C.; Nau, Dana S. (Concurrent EngineeringConcurrent Engineering, 1994)
The increasing focus on design for manufacturability (DFM) in research in concurrent engineering and engineering design is expanding the scope of traditional design activities in order to identify and eliminate manufacturing problems during the design stage. Manufacturing a product generally involves many different kinds of manufacturing activities, each having different characteristics. A design that is good for one kind of activity may not be good for another; for example, a design that is easy to assemble may not be easy to machine. One obstacle to DFM is the difficulty involved in building a single system that can handle the various manufacturing domains relevant to a design.
Keywords: design critiquing; design for manufacturability; feature-based modeling; manufacturability analysis; multi-agent coordination.

Modeling brain adaptation to focal damage. - Goodall,S.; Reggia, James A.; Cho,S. (Proceedings of the Annual Symposium on Computer Application in Medical Care, 1994)

Next Generation Network Management Technology - Atallah,George C; Ball,Michael O; Baras,John S; Goli,Shravan K; Karne,Ramesh K; Kelley,Stephen; Kumar,Harsha P.; Plaisant, Catherine; Roussopoulos, Nick; Shneiderman, Ben; Srinivasarao,Mulugu; Stathatos,Kostas; et al. (Institute for Systems Research Technical Reports, 1994)
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 The 12th Symposium on Space Nuclear Power and Propulsion/Commercialization, pp. 75-82, Albuquerque, NM, January 8-12, 1995.
Keywords: Constraints for Network Management.; Network Configuration Management; network management; Object Oriented Data Base Model for Network Management; Rules; Systems Integration; Visual Information Management for Network Configuration Management

Optimal parallel approximation for prefix sums and integer sorting - Goodrich,M. T; Matias,Y.; Vishkin, Uzi (Proceedings of the fifth annual ACM-SIAM symposium on Discrete algorithms, 1994)

Regularization by Truncated Total Least Squares - Fierro,Richardo; Golub, Gene H.; Hansen,Per Christian; O'Leary, Dianne P. (Proceedings of the Fifth SIAM Conference on Applied Linear Algebra, 1994)

Software Specification: A Comparison of Formal Methods - Gannon,John D.; Purtilo,James; Zelkowitz, Marvin V (Intellect Books, 1994)
Keywords: Computer software; Computer software/ Specifications; Computers / General; Computers / Programming / General; Formal methods (Computer science); software engineering; specifications

Some Themes in Gene H.Golub's Work on Iterative Methods - O'Leary, Dianne P. (Recent Advances in Iterative MethodsRecent Advances in Iterative Methods, 1994)

A study of affine matching with bounded sensor error - Grimson,W. E.L; Huttenlocher,D. P; Jacobs, David W. (International Journal of Computer Vision, 1994)
Affine transformations of the plane have been used in a number of model-based recognition systems. Because the underlying mathematics are based on exact data, in practice various heuristics are used to adapt the methods to real data where there is positional uncertainty. This paper provides a precise analysis of affine point matching under uncertainty. We obtain an expression for the range of affine-invariant values that are consistent with a given set of four points, where each image point lies in an isin-disc of uncertainty. This range is shown to depend on the actualx-y-positions of the data points. In other words, given uncertainty in the data there are no representations that are invariant with respect to the Cartesian coordinate system of the data. This is problematic for methods, such as geometric hashing, that are based on affine-invariant representations. We also analyze the effect that uncertainty has on the probability that recognition methods using affine transformations will find false positive matches. We find that there is a significant probability of false positives with even moderate levels of sensor error, suggesting the importance of good verification techniques and good grouping techniques.

Visualization in the information highway - Gershon,Nahum; Card,Stuart K.; Roth,Steven F.; Shneiderman, Ben (Proceedings of the conference on Visualization '94, 1994)

Approximate parallel prefix computation and its applications - Goodrich,M. T; Matias,Y.; Vishkin, Uzi (Parallel Processing Symposium, 1993., Proceedings of Seventh International, 1993)

Concurrent evaluation of machinability during product design - Gupta,S.K.; Nau, Dana S.; Zhang, G. (Computer, 1993)
An approach to evaluating the machinability of a part during the design stage, which performs systematic generation and evaluation of machining alternatives, is discussed. The results of the analysis provide feedback to the designer about problems that might arise with the machining and information to the manufacturing engineer about which machining processes and process parameters are most desirable.<<ETX>>
Keywords: concurrent engineering; concurrent evaluation; machinability; machining; manufacturing engineer; product design

Development of machining alternatives, based on MRSEVs - Nau, Dana S.; Gupta,S.K.; Kramer,T. R.; Regli,W. C.; Zhang, G. (Computers in Engineering, 1993)
One missing link between CAD and CAM is the lack ofa systematic methodology for generating and evaluating al- ternative ways to manufacture a proposed design. To ad- dress this problem, we are developing a systematic approach for generating and evaluating alternative ways to manufac- ture machined parts, in order to provide information to the designer about the manufacturability of the proposed de- sign, and information to the process engineer about how best to machine the part. This paper describes our overall approach, and how MRSEVs (Material Removal Shape El- ement Volumes, a STEP library of machining features) can be used to support it.

Estimation of Achievable Tolerances - Gupta, Satyandra K.; Nau, Dana S.; Zhang,G. M. (Institute for Systems Research, University of Maryland, College Park, 1993)
This report presents a new and systematic approach to assist decision-making in selecting machining operation plans. We present a methodology to estimate achievable tolerances of operations plan. Given an operation plan, we use variety of empirical and mathematical models to evaluate process capabilities of various machining operations and compute achievable tolerances using tolerance charting techniques.
Keywords: Automation; computer aided manufacturing; Manufacturing; Manufacturing Systems

Evaluating product machinability for concurrent engineering - Nau, Dana S.; Zhang, G.; Gupta,S.K.; Karinthi,R. R. (Concurrent Engineering: Contemporary Issues and Modern Design Tools, 1993)

Generation of alternative feature-based models and precedence orderings for machining applications - Gupta, Satyandra K.; Nau, Dana S. (ACM, 1993)

Interpreting Product Designs for Manufacturability Evaluation - Gupta, Satyandra K.; Nau, Dana S.; Zhang,G. M. (Institute for Systems Research, University of Maryland, College Park, 1993)
The ability to quickly introduce new quality products is a decisive factor in capturing market share. Because of pressing demands to reduce lead time, analyzing the manufacturability of the proposed design has become an important step in the design stage. In this paper we present an approach for evaluating the manufacturability of machined parts. Evaluating manufacturability involves finding a way to manufacture the proposed design, and estimating the associated production cost and quality. However, there often can be several different ways to manufacture a proposed design - so to evaluate the manufacturability of the proposed design, we need to consider different ways to manufacture it, and determine which one best meets the manufacturing objectives. In this paper we describe a methodology for systematically generating and evaluating alternative operation plans. As a first step, we identify all machining operations which can potentially be used to create the given design. Using these operations, we generate different operation plans for machining the part. Each time we generate a new operation plan, we assign it a manufacturability rating. The manufacturability rating for the design is the rating of the best operation plan. We anticipate that by providing feedback about possible problems with the design, this work will be useful in providing a way to speed up the evaluation of new product designs in order to decide how or whether to manufacture them.
Keywords: Automation; computer aided manufacturing; manufacturability; Manufacturing Systems

Performance Enhancements and Parallel Algorithms for Two Multilevel Preconditioners - Elman, Howard; Guo,Xian-Zhong (SIAM Journal on Scientific ComputingSIAM J. Sci. Comput., 1993)

Point probe decision trees for geometric concept classes - Arkin,E.; Goodrich,M.; Mitchell,J.; Mount, Dave; Piatko,C.; Skiena,S. (Algorithms and Data Structures, 1993)
A fundamental problem in model-based computer vision is that of identifying to which of a given set of concept classes of geometric models an observed model belongs. Considering a ldquoproberdquo to be an oracle that tells whether or not the observed model is present at a given point in an image, we study the problem of computing efficient strategies (ldquodecision treesrdquo) for probing an image, with the goal to minimize the number of probes necessary (in the worst case) to determine in which class the observed model belongs. We prove a hardness result and give strategies that obtain decision trees whose height is within a log factor of optimal.These results grew out of discussions that began in a series of workshops on Geometric Probing in Computer Vision, sponsored by the Center for Night Vision and Electro-Optics, Fort Belvoir, Virginia, and monitored by the U.S. Army Research Office. The views, opinions, and/or findings contained in this report are those of the authors and should not be construed as an official Department of the Army position, policy, or decision, unless so designated by other documentation.

Species-specific signals for the splicing of a short Drosophila intron in vitro. - Guo,M.; Lo,P. C.; Mount, Stephen M. (Molecular and Cellular BiologyMol. Cell. Biol., 1993)
The effects of branchpoint sequence, the pyrimidine stretch, and intron size on the splicing efficiency of the Drosophila white gene second intron were examined in nuclear extracts from Drosophila and human cells. This 74-nucleotide intron is typical of many Drosophila introns in that it lacks a significant pyrimidine stretch and is below the minimum size required for splicing in human nuclear extracts. Alteration of sequences of adjacent to the 3' splice site to create a pyrimidine stretch was necessary for splicing in human, but not Drosophila, extracts. Increasing the size of this intron with insertions between the 5' splice site and the branchpoint greatly reduced the efficiency of splicing of introns longer than 79 nucleotides in Drosophila extracts but had an opposite effect in human extracts, in which introns longer than 78 nucleotides were spliced with much greater efficiency. The white-apricot copia insertion is immediately adjacent to the branchpoint normally used in the splicing of this intron, and a copia long terminal repeat insertion prevents splicing in Drosophila, but not human, extracts. However, a consensus branchpoint does not restore the splicing of introns containing the copia long terminal repeat, and alteration of the wild-type branchpoint sequence alone does not eliminate splicing. These results demonstrate species specificity of splicing signals, particularly pyrimidine stretch and size requirements, and raise the possibility that variant mechanisms not found in mammals may operate in the splicing of small introns in Drosophila and possibly other species.

A Systematic Approach for Analyzing the Manufacturability of Machined Parts - Gupta, Satyandra K.; Nau, Dana S. (Institute for Systems Research, University of Maryland, College Park, 1993)
The ability to quickly introduce new quality products is a decisive factor in capturing market share. Because of pressing demands to reduce lead time, analyzing the manufacturability of the proposed design has become an important step in the design stage. This paper presents an approach for analyzing the manufacturability of machined parts. Evaluating the manufacturability of a proposed design involves determining whether or not it is manufacturable with a given set of manufacturing operations - and if so, then finding the associated manufacturing efficiency. Since there can be several different ways to manufacture a proposed design, this requires us to consider different ways to manufacture it, in order to determine which one best meets the design and manufacturing objectives. The first step in our approach is to identify all machining operations which can potentially be used to create the given design. Using these operations, we generate different operation plans for machining the part. Each time we generate a new operation plan, we examine whether it can produce the desired shape and tolerances, and calculate its manufacturability rating. If no operation plan can be found that is capable of producing the design, then the given design is considered unmachinable; otherwise, the manufacturability rating for the design is the rating of the best operation plan. We anticipate that by providing feedback about possible problems with the design, this work will help in speeding up the evaluation of new product designs in order to decide how or whether to manufacture them. Such a capability will be useful in responding quickly to changing demands and opportunities in the marketplace.
Keywords: Automation; computer aided manufacturing; Feature extraction; manufacturability; Systems Integration

Using MRSEVs to develop machining alternatives - Nau, Dana S.; Gupta,S.K.; Kramer,T. R.; Regli,W. C.; Zhang, G. (1993)

On the difficulty of Manhattan channel routing - Greenberg,Ronald; JaJa, Joseph F.; Krishnamurthy,Sridhar (Information Processing Letters, 1992)
We show that channel routing in the Manhattan model remains difficult even when all nets are single-sided. Given a set of n single-sided nets, we consider the problem of determining the minimum number of tracks required to obtain a dogleg-free routing. In addition to showing that the decision version of the problem isNP-complete, we show that there are problems requiring at least d+Ω(n) tracks, where d is the density. This existential lower bound does not follow from any of the known lower bounds in the literature.
Keywords: combinatorial problems; computational complexity; lower bounds; VLSI channel routing

General of Machining Alternatives for Machinability Evaluation - Gupta, Satyandra K.; Nau, Dana S.; Zhang,G. M. (Institute for Systems Research, University of Maryland, College Park, 1992)
This paper presents a new methodology for evaluating the machinability of a machined part during the design stage of the product development cycle, so that problems related to machining can be recognized and corrected while the product is being designed. Our basic approach is to perform a systematic evaluation of machining alternatives throughout each step in the design stage. This involves three basic steps: (1) generate alternative interpretations of the design as different collections of machinable features, (2) generate the various possible sequences of machining operations capable of producing each interpretation, and (3) evaluate each operation sequence, to determine the relevant information on achievable quality and associated costs. The information provided by this analysis can be used not only to give feedback to the designer about problems that might arise with the machining, but also to provide information to the manufacturing engineer about alternative ways in which the part might be machined.
Keywords: Automation; computer aided manufacturing; manufacturability; Manufacturing Systems

Generation and Evaluation of Alternative Operation - Nau, Dana S.; Zhang,G. M.; Gupta, Satyandra K. (Institute for Systems Research, University of Maryland, College Park, 1992)
This paper presents a new and systematic approach to assist decision-making in selecting machining operation sequences. The approach is to produce alternative interpretations of design as different collections of machinable features, use these interpretations to generate alternative machining operation sequences, and evaluate the cost and achievable machining accuracy of each operations sequence. Given the operation sequences and their evaluations, it is then possible to calculate the performance measures of interest, and use these performance measures to select, from among the various alternatives, one or more of them that can best balance the need for a quality product against the need for efficient machining.
Keywords: Automation; computer aided manufacturing; computer integrated manufacturing; Feature extraction; flexible manufacturing; Manufacturing; Manufacturing Systems; Solid modeling

Generation of Machining Alternatives for Machinability Evaluation - Gupta, Satyandra K.; Nau, Dana S.; Zhang,G. M. (Institute for Systems Research, University of Maryland, College Park, 1992)
This paper presents a new methodology for evaluating the machinability of a machined part during the design stage of the product development cycle, so that problems related to machining can be recognized and corrected while the product is being designed. Our basic approach is to perform a systematic evaluation of machining alternatives throughout each step in the design stage. This involves three basic steps: (1) generate alternative interpretations of the design as different collections of machinable features, (2) generate the various possible sequences of machining operations capable of producing each interpretation, and (3) evaluate each operation sequence, to determine the relevant information on achievable quality and associated costs. The information provided by this analysis can be used not only to give feedback to the designer about problems that might arise with the machining, but also to provide information to the manufacturing engineer about alternative ways in which the part might be machined.
Keywords: Automation; computer aided manufacturing; manufacturability; Manufacturing Systems

PARTI primitives for unstructured and block structured problems - Sussman, Alan; Saltz, J.; Das,R.; Gupta,S.; Mavriplis,D.; Ponnusamy,R.; Crowley,K. (Computing Systems in Engineering, 1992)
This paper describes a set of primitives (PARTI) developed to efficiently execute unstructured and block structured problems on distributed memory parallel machines. We present experimental data from a three-dimensional unstructured Euler solver run on the Intel Touchstone Delta to demonstrate the usefulness of our methods.

Reflecting time in generated text: tense, aspect and temporal connecting words - Dorr, Bonnie J; Gaasterland,Terry (University of Maryland at College Park, 1992)

A study of affine matching with bounded sensor error - Grimson,W.; Huttenlocher,D.; Jacobs, David W. (Computer Vision—ECCV'92, 1992)
Affine transformations of the plane have been used by modelbased recognition systems to approximate the effects of perspective projection. Because the underlying mathematics are based on exact data, in practice various heuristics are used to adapt the methods to real data where there is positional uncertainty. This paper provides a precise analysis of affine point matching under uncertainty. We obtain an expression for the range of affine-invariant values consistent with a given set of four points, where each data point lies in an exist-disc. This range is shown to depend on the actual x- y-positions of the data points. Thus given uncertainty in the data, the representation is no longer invariant with respect to the Cartesian coordinate system. This is problematic for methods, such as geometric hashing, that depend on the invariant properties of the representation. We also analyze the effect that uncertainty has on the probability that recognition methods using affine transformations will find false positive matches. We find that such methods will produce false positives with even moderate levels of sensor error.

An algebra and calculus for relational multidatabase systems - Grant,J.; Litwin,W.; Roussopoulos, Nick; Sellis,T. (, First International Workshop on Interoperability in Multidatabase Systems, 1991. IMS '91. Proceedings, 1991)
With the existence of many autonomous databases widely accessible through computer networks, users will require the capability to jointly manipulate data in different databases. A multidatabase system provides such a capability through a multidatabase manipulation language. The authors propose a theoretical foundation for such languages by presenting a multirelational algebra and calculus based on the relational algebra and calculus. The proposal is illustrated by various queries on an example multidatabase
Keywords: Algebra; autonomous databases; Calculus; Computer networks; Computer science; Data models; Data structures; Database systems; database theory; distributed databases; Military computing; multidatabase manipulation language; multidatabase system; multirelational algebra; query languages; relational algebra; Relational databases; Spatial databases; theoretical foundation

An experimental study of criteria for hypothesis plausibility - Tuhrim,S.; Reggia, James A.; Goodall,S. (Journal of Experimental & Theoretical Artificial Intelligence, 1991)

Iterative methods for cyclically reduced non-self-adjoint linear systems II - Elman, Howard; Golub, G. H (Math. Comp, 1991)

Towards a theory of nearly constant time parallel algorithms - Gil,J.; Matias,Y.; Vishkin, Uzi (Foundations of Computer Science, 1991. Proceedings., 32nd Annual Symposium on, 1991)
It is demonstrated that randomization is an extremely powerful tool for designing very fast and efficient parallel algorithms. Specifically, a running time of <e1>O</e1>(lg* <e1>n</e1>) (nearly-constant), with high probability, is achieved using <e1>n</e1>/lg* <e1>n</e1> (optimal speedup) processors for a wide range of fundamental problems. Also given is a constant time algorithm which, using <e1>n</e1> processors, approximates the sum of <e1>n</e1> positive numbers to within an error which is smaller than the sum by an order of magnitude. A variety of known and new techniques are used. New techniques, which are of independent interest, include estimation of the size of a set in constant time for several settings, and ways for deriving superfast optimal algorithms from superfast nonoptimal ones
Keywords: computational complexity; Estimation; nearly constant time parallel algorithms; Parallel algorithms; positive numbers; randomization; running time; superfast optimal algorithms

Investigation of the threshold voltage of MOSFETs with position and potential-dependent interface trap distributions using a fixed-point iteration method - Gaitan,M.; Mayergoyz, Issak D; Korman,C.E. (Electron Devices, IEEE Transactions on, 1990)
Simulation results are presented for a MOSFET with position- and energy- (potential-) dependent interface trap distributions that may be typical for devices subjected to interface-trap-producing processes such as hot-electron degradation. The interface-trap distribution is modeled as a Gaussian peak at a given position along the channel, and the energy dependence is derived from <e1>C</e1>-<e1>V</e1> measurements from an MOS capacitor exposed to ionizing radiation. A novel fixed-point technique is used to solve the two-dimensional boundary-value problem. The technique is shown to be globally convergent for arbitrary distributions of interface traps. A comparison of the convergence properties of the Newton and fixed-point methods is presented, and it is shown that for some important cases the Newton technique fails to converge while the fixed-point technique converges with a geometric convergence rate
Keywords: boundary-value; C-V; carriers; insulated; characteristics; Gaussian; Convergence; convergence; hot-electron; degradation; position; dependence; fixed-point; dependent; device; distribution; potential-dependent; distributions; simulation; threshold; effect; electron; field; gate; interface; iteration; method; fixed-point; methods; hot; methods; semiconductor; models; numerical; of; peak; MOSFET; energy; problem; boundary-value; problems; convergence; rate; global; states; iterative; technique; geometric; transistors; interface; trap; voltage; two-dimensional

Iterative methods for cyclically reduced non-self-adjoint linear systems - Elman, Howard; Golub, G. H (Math. Comp, 1990)

Line iterative methods for cyclically reduced discrete convection-diffusion problems - Elman, Howard; Golub, G. H (University of Maryland, 1990)

3D object recognition via simulated particles diffusion - Yacoob,Yaser; Gold,Y. I (IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 1989. Proceedings CVPR '89, 1989)
A novel approach for 3D object recognition is presented. This approach is model-based, and assumes either 3D or 21/2 D scene acquisition. Transformation detection is accomplished along with an object identification (six degrees of freedom, three rotational and three translational, are assumed). The diffusion-like simulation recently introduced as a means for characterization of shape is used in the extraction of point features. The point features represent regions on the object's surface that are extreme in curvature (i.e. concavities and convexities). Object matching is carried out by examining the correspondence between the object's set of point features and the model's set of point features, using an alignment strategy. Triangles are constructed between all possible triples of object's point features, and then are aligned to candidate corresponding triangles of the model's point features. 21/2 range images are transformed into a volumetric representation through a parallel projection onto the 3-D space. The resultant volume is suitable for processing by the diffusion-like simulation
Keywords: 3D object recognition; alignment strategy; Computational modeling; Computer science; data mining; Gold; Layout; Noise shaping; Object detection; Object recognition; parallel projection; pattern recognition; point features; radio access networks; scene acquisition; shape characterisation; Shape measurement; simulated particles diffusion; transformation detection

A connectionist model for dynamic control - Whitfield,K. C; Goodall,S. M; Reggia, James A. (Telematics and Informatics, 1989)

Domino: A Transportable System for Parallel Processing - O'Leary, Dianne P.; Stewart, G.W.; Geijn,Robert van de (Parallel Processing and Medium-Scale Multiprocessors (Proceedings of a 1986 Conference)Parallel Processing and Medium-Scale Multiprocessors (Proceedings of a 1986 Conference), 1989)

Dynamic bin packing problem - Dikshit,Piyush; Guimaraes,Katia; Ramamurthy,Maya; Agrawala, Ashok K.; Larsen,Ronald L (SIAM Journal on Computing, 1989)
In a previous work we have defined a general architecture model for autonomous systems, which can be mapped easily to describe the functions of any automated system (SDAG-86-01). In this note, we use the model to describe the problem of thermal management in space stations. First we briefly review the architecture, then we present the environment of our application, and finally we detail the specific function for each functional block of the architecture for that environment.

Explicitly biased generalization - Gordon,D.; Perlis, Don (Computational Intelligence, 1989)

Functional and psychosocial effects of multimodality limb-sparing therapy in patients with soft tissue sarcomas - Chang,A. E; Steinberg,S. M; Culnane,M.; Lampert,M. H; Reggia, James A.; Simpson,C. G; Hicks,J. E; White,D. E; Yang,J. J; Glatstein,E. (Journal of Clinical Oncology, 1989)

Gabriel: A design environment for DSP - Lee,E. A; Ho,W. H; Goei,E. E; Bier,J. C; Bhattacharyya, Shuvra S. (Acoustics, Speech and Signal Processing, IEEE Transactions on, 1989)

Hypertext and software engineering - Balzer,R.; Begeman,M.; Garg,P. K.; Schwartz,M.; Shneiderman, Ben (Proceedings of the second annual ACM conference on Hypertext, 1989)
The purpose of this panel is to bring together researchers in software engineering and hypertext and help identify the major issues in the application of hypertext technology and concepts to software engineering and vice versa.

A numerical analysis for the small-signal response of the MOS capacitor - Gaitan,Michael; Mayergoyz, Issak D (Solid-State Electronics, 1989)
Simulation results for the small-signal sinusoidal steady-state response of the MOS capacitor using time perturbation analysis of the basic semiconductor equations are presented. The effects of interface and bulk trap dynamics are included. The model uses Fermi-Dirac statistics and Shockley-Read-Hall recombination to describe the traps. This analysis is an improvement over previous techniques since it can simulate the effect of trap dynamics on the small-signal sinusoidal steady-state response of a semiconductor device with arbitrary geometry, doping and trap distributions.

Some History of the Conjugate Gradient and Lanczos Algorithms: 1948–1976 - Golub, Gene H.; O'Leary, Dianne P. (SIAM Review, 1989)
This paper gives some of the history of the conjugate gradient and Lanczos algorithms and an annotated bibliography for the period 1948-1976
Keywords: Conjugate gradient algorithm; Lanczos algorithm; variable metric algorithms

A general-purpose simulation environment for developing connectionist models - D'Autrechy,C. L; Reggia, James A.; Sutton,G. G; Goodall,S. M (Simulation, 1988)

Partial Revertants of the Transposable Element-Associated Suppressible Allele White-Apricot in Drosophila Melanogaster: Structures and Responsiveness to Genetic Modifiers - Mount, Stephen M.; Green,M. M.; Rubin,G. M. (GeneticsGenetics, 1988)
The eye color phenotype of white-apricot (w(a)), a mutant allele of the white locus caused by the insertion of the transposable element copia into a small intron, is suppressed by the extragenic suppressor suppressor-of-white-apricot (su(w(a))) and enhanced by the extragenic enhancers suppressor-of-forked su(f)) and Enhancer-of-white-apricot (E(w(a))). Derivatives of w(a) have been analyzed molecularly and genetically in order to correlate the structure of these derivatives with their response to modifiers. Derivatives in which the copia element is replaced precisely by a solo long terminal repeat (sLTR) were generated in vitro and returned to the germline by P-element mediated transformation; flies carrying this allele within a P transposon show a nearly wild-type phenotype and no response to either su(f) or su(w(a)). In addition, eleven partial phenotypic revertants of w(a) were analyzed. Of these, one appears to be a duplication of a large region which includes w(a), three are new alleles of su(w(a)), two are sLTR derivatives whose properties confirm results obtained using transformation, and five are secondary insertions into the copia element within w(a). One of these, w(aR84h), differs from w(a) by the insertion of the most 3' 83 nucleotides of the I factor. The five insertion derivatives show a variety of phenotypes and modes of interaction with su((f) and su(w(a)). The eye pigmentation of w(aR84h) is affected by su(f) and E(w(a)), but not su(w(a)). These results demonstrate that copia (as opposed to the interruption of white sequences) is essential for the w(a) phenotype and its response to genetic modifiers, and that there are multiple mechanisms for the alteration of the w(a) phenotype by modifiers.

Computer-supported cooperative work (panel): is this REALLY a new field of research? - Greif,Irene; Curtis,Bill; Krasner,Herb; Malone,Thomas W.; Shneiderman, Ben (Proceedings of the SIGCHI/GI conference on Human factors in computing systems and graphics interface, 1987)

Direct manipulation user interfaces for expert systems - Baroff,J.; Simon,R.; Gilman,F.; Shneiderman, Ben (Expert systems: the user interfaceExpert systems: the user interface, 1987)

Mapping a single-assignment language onto the Warp systolic array - Gross,T.; Sussman, Alan (Functional Programming Languages and Computer Architecture, 1987)

An output sensitive algorithm for computing visibility graphs - Ghosh,Subir Kumar; Mount, Dave (Foundations of Computer Science, 1987., 28th Annual Symposium on, 1987)
The visibility graph of a set of nonintersecting polygonal obstacles in the plane is an undirected graph whose vertices are the vertices of the obstacles and whose edges are pairs of vertices (u, v) such that the open line segment between u and v does not intersect any of the obstacles. The visibility graph is an important combinatorial structure in computational geometry and is used in applications such as solving visibility problems and computing shortest paths. An algorithm is presented that computes the visibility graph of s set of obstacles in time O(E + n log n), where E is the number of edges in the visibility graph and n is the total number of vertices in all the obstacles.

TIME PERTURBATION ANALYSIS FOR THE MOS SYSTEM - Gaitan,Michael; Mayergoyz, Issak D (COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 1987)
The development of a numerical implementation of the small signal response of the MOS (Metal-Oxide-Silicon) capacitor using time perturbation analysis is discussed. The effects of nonconstant doping profiles and interface and bulk traps are included. The model uses Fermi-Dirac statistics to describe the occupancy of the interface and bulk traps. The oxide region is considered to have no mobile carriers and any fixed oxide charge distribution is modeled as a charge sheet at the Si-SiO2 interface. This technique can be used to find the small signal response of the device from the static solution.

Two implementation models of abstract data types - Gannon,John D.; Zelkowitz, Marvin V (Computer Languages, 1987)
This paper compares two implementation models for abstract data types: direct and indirect implementations. Direct implementations offer relatively cheap execution and expensive compilation costs while indirect implementations result in relatively expensive implementations and cheap compilation costs. These two models are both accommodated by Ada, and a small experiment compares their costs for a particular data type.
Keywords: abstract data type; ada; run-time implementation

Research in Programming Languages and Software Engineering. - Gannon,John; Basili, Victor R.; Zelkowitz, Marvin V; Yeh,Raymond (Department of Computer Science, University of Maryland, College Park, 1985)
During the past year three research papers were written and two published conference presentations were given. Titles of the published research articles are: A Stochastic Analysis of a Modified Gain Extended Kalman Filter with Applications to Estimation with Bearings only Measurements; The Modified Gain Extended Kalman Kilter and Parameter Identification in Linear Systems and Maximum Information Guidance for Homing Missiles.
Keywords: *BEARINGS; *COMPUTER PROGRAMS; *ESTIMATES; *GUIDANCE; *KALMAN FILTERING; *LINEAR SYSTEMS; *STOCHASTIC PROCESSES; COMPUTER PROGRAMMING AND SOFTWARE; GAIN; identification; measurement; programming languages; STATISTICS AND PROBABILITY; SYSTEMS ENGINEERING.; TARGET DIRECTION, RANGE AND POSITION FINDING

Monitoring an Ada software development - Basili, Victor R.; Chang,Shih; Gannon,John; Katz,Elizabeth; Panlilio-Yap,N. Monina; Ramsey,Connie Loggia; Zelkowitz, Marvin V; Bailey,John; Kruesi,Elizabeth; Sheppard,Sylvia (ACM SIG Ada Letters, 1984)

Software Engineering Practices in the US and Japan - Zelkowitz, Marvin V; Yeh,R. T; Hamlet,R.G.; Gannon,J. D; Basili, Victor R. (Computer, 1984)

Solving NP-hard problems on graphs that are almost trees and an application to facility location problems - Gurevich,Y.; Stockmeyer,L.; Vishkin, Uzi (Journal of the ACM (JACM), 1984)

Evaluating multiple coordinated windows for programming workstations - Shneiderman, Ben; GRANTHAM,C.; Norman,K.; ROGERS,J.; Roussopoulos, Nick (NASA. Goddard Space Flight Center Proc. of the Eighth Ann. Software Eng. Workshop 11 p(SEE N 84-23137 13-61), 1983)
Programmers might benefit from larger screens with multiple windows or multiple screens, especially if convenient coordination among screens are arranged. Uses for multiple coordinated displays in a programmers workstation are explored. Initial efforts focus on the potential applications, a command language for coordinating the displays, and the psychological basis for effective utilization so as to avoid information overload. Subsequent efforts will be devoted to implementing the concepts and performing controlled psychologically oriented experiments to validate the hypotheses.

Small Ribonucleoproteins from Eukaryotes: Structures and Roles in RNA Biogenesis - Steitz,J. A.; Wolin,S. L.; Rinke,J.; Pettersson,I.; Mount, Stephen M.; Lerner,E. A.; Hinterberger,M.; Gottlieb,E. (Cold Spring Harbor Symposia on Quantitative BiologyCold Spring Harb Symp Quant Biol, 1983)
Detailed reviews describing work presented at the annual Cold Spring Harbor Symposia on Quantitative Biology

The Software Industry: A State of the Art Survey - Zelkowitz, Marvin V; Yeh,R.; Hamlet,R.G.; Gannon,J. D; Basili, Victor R. (Foundations of Empirical Software Engineering: The Legacy of Victor R. Basili, 1983)

Isomorphism of graphs with bounded eigenvalue multiplicity - Babai,László; Grigoryev,D. Yu.; Mount, Dave (Proceedings of the fourteenth annual ACM symposium on Theory of computing, 1982)
We investigate the connection between the spectrum of a graph, i.e. the eigenvalues of the adjacency matrix, and the complexity of testing isomorphism. In particular we describe two polynomial time algorithms which test isomorphism of undirected graphs whose eigenvalues have bounded multiplicity. If X and Y are graphs of eigenvalue multiplicity m, then the isomorphism of X and Y can be tested by an O(n4m+c) deterministic and by an O(n2m+c) Las Vegas algorithm, where n is the number of vertices of X and Y.

Structure and function of small ribonucleoproteins from eukaryotic cells - Steitz,J. A.; Berg,C; Gottlieb,E.; Hardin,J A; Hashimoto,C; Hendrick,J P; Hinterberger,M.; Krikeles,M; Lerner,M R; Mount, Stephen M. (Princess Takamatsu symposiaInt. Symp. Princess Takamatsu Cancer Res. Fund, 1982)
Autoantibodies from patients with systemic lupus erythematosus and other related diseases have been used to identify and study small RNA-protein complexes from mammalian cells. Properties of three previously described and several new classes of small ribonucleoproteins (RNPs) are reviewed. The sequence of Drosophila U1 RNA reveals that the region proposed to pair with 5' splice junctions is conserved, while that proposed to interact with 3' junctions diverges; this forces some revision of the model for U1 small nuclear (sn)RNP participation in hnRNA splicing. Further characterization of the Ro and La small RNPs has shown that the Ro small cytoplasmic (sc)RNPs are a subclass of La RNPs. Both tRNA and 5S rRNA precursors are at least transiently associated with the La protein. This raises the possibility that the La protein may be an RNA polymerase III transcription factor.
Keywords: Antigen-Antibody Complex; Autoantibodies; HUMANS; Lupus Erythematosus, Systemic; Nucleoproteins; Ribonucleoproteins; RNA Polymerase III; Transcription, Genetic

Principles of software engineering and design - Zelkowitz, Marvin V; Shaw,A. C; Gannon,J. D (Prentice Hall Professional Technical Reference, 1979)

Numerical Solution of Nonlinear Elliptic Partial Differential Equations by a Generalized Conjugate Gradient Method - Concus,Paul; Golub, Gene H.; O'Leary, Dianne P. (Computing, 1978)
We have studied previously a generalized conjugate gradient method for solving sparse positive-definite systems of linear equations arising from the discretization of elliptic partial-differential boundary-value problems. Here, extensions to the nonlinear case are considered. We split the original discretized operator into the sum of two operators, one of which corresponds to a more easily solvable system of equations, and accelerate the associated iteration based on this splitting by (nonlinear) conjugate gradients. The behavior of the method is illustrated for the minimal surface equation with splittings corresponding to nonlinear SSOR, to approximate factorization of the Jacobian matrix, and to elliptic operators suitable for use with fast direct methods. The results of numerical experiments are given as well for a mildy nonlinear example, for which, in the corresponding linear case, the finite termination property of the conjugate gradient algorithm is crucial.

A Generalized Conjugate Gradient Method for the Numerical Solution of Elliptic Partial Differential Equations - Concus,Paul; Golub, Gene H.; O'Leary, Dianne P. (Sparse Matrix ComputationsSparse Matrix Computations, 1976)
We consider a generalized conjugate gradient method for solvingsparse, symmetric, positive-definite systems of linear equations, principally those arising from the discretization of boundary value problems for elliptic partial differential equations. The method is based on splitting off from the original coefficient matrix a symmetric, positive-definiteonethat corresponds to a more easily solvable system of equations, and then accelerating the associated iteration using conjugate gradients. Optimality and convergence properties are presented, and the relation to other methods is discussed. Several splittings for which the method seems particularly effective are also discussed, and for some, numerical examples are given