Faculty Research & Interests

Fall 1998

Department of Computer Science

Iowa State University

226 Atanasoff Hall

Ames IA 50011

515-294-4377

Department of Computer Science

Computing activities began at Iowa State in the late 1930's when John Vincent Atanasoff, a professor of physics and mathematics, built a computer on campus that is now recognized as the first electronic digital computer.

The Department of Computer Science was established as a formal discipline in 1969, offering from the outset the B.S., M.S. and Ph.D. degrees. The department now has approximately 2,500 alumni.

At present, there are 18 tenured and tenure-track faculty, four adjunct faculty, four instructors, and one industrial affiliate. Support staff includes an administrative specialist, three departmental secretaries, two undergraduate advisors, and two software analysts. Enrolled are approximately 600 undergraduate majors, 75 Master's students and 13 Ph.D. students. Each year, most of the graduate students are supported by either a teaching assistant position in the department or by research assistant positions in the department and other university laboratories.

The atmosphere of the department is such that research, interaction with students, and teaching are all considered to be important activities. Development and continued maintenance of active research programs involving graduate students and faculty are basic objectives. New research programs receive substantial departmental support. Research interests cover a broad spectrum of areas and, in addition, there exist close ties with faculty in several other departments and centers.

In support of its research and instruction, the department owns and operates a LAN consisting of numerous HP workstations and terminals. The computers run under variants of the UNIX operating system and networking is made uniform through the TCP/IP protocol and the Network File System standard. Other LANs, consisting of more than 60 HP Vectra PCs running under Windows ’95 and Windows NT, are bridged to the main LAN and provides additional instructional support. Connected to a campus-wide fiber optics network, departmental facilities have access to high-speed global Internet communication.

Additional university facilities include the Scalable Computing Laboratory, which has several parallel computers including both SIMD and MIMD machines, and the Computation Center which supports a university-wide Athena-like network of file servers, workstations, and PCs.

More information about the department and a more complete description of faculty research can be retrieved through the World Wide Web at http://www.cs.iastate.edu.

Department of Computer Science

Iowa State University

B.A. 1974, Mathematics, Drake University

M.S. 1976, Computer Science, The Ohio State University

Ph.D. 1979, Computer Science, The Ohio State University

Software Engineering (Specification Languages, CASE Tools), Natural Language Text Analysis.

Dr. Baker's recent work in Software Engineering is focused on formal specification languages. He has developed a model-based, formal specification language for C++ classes - SPECS++. This is a typical model-based specification language in that class values are modeled as discrete mathematical structures and operations are specified using precondition and post condition first order assertions. SPECS++ handles inheritance, templates and objects. He has also, along with Dr. Leavens, developed a similar model-based specification language for Java called JML (Java Modeling Language). JML retains the expression syntax of Java and includes expressively convenient features like specification examples and redundant assertions.

A compiler for an executable subset of SPECS-C++ has been implemented. This subset is based on "constructive assertions," which are just those assertions which can be executed using the constraint resolution technique developed for this purpose. Thus, while SPECS-C++ retains the precision and level of abstraction achieved by other model-based specification languages, it has the added advantage of yielding an executable prototype directly from a class specification. SPECS++ is intended as a practical tool usable by professional software developers to specify and prototype C++ classes.

Dr. Baker is also developing a graphics-based language for specifying concurrent and distributed systems. Computer-Aided Software Engineering (CASE) tools that can be used for specifications are typically graphics oriented, but do not support rigorous definitions of software functionality. The system under development supports formal specification of software functionality, and like SPECS++, is executable. In fact, the "messages" in this graphics-based system can be modeled using SPECS++. Dr. Baker has designed several enhancements to commercially available CASE tools based on his results in abstract model formal specifications. The basic results from this line of research are now being applied to the specification of large computer networks and the automated generation of simulations of these networks.

Dr. Baker’s research in Natural Language Text Analysis has led to software systems that support the analysis of verbatim responses to open-ended questions (as might be used in population survey research). These systems allow for the efficient identification, coding and recognition of the significant concepts in verbatim responses. His recent results support the identification of relations between concepts, and can be used as the basis of natural language database systems with natural language interfaces to large volumes of natural language text.

"Preliminary Design of JML: A Behavioral Interface Specification Language for Java", Baker, A.L., Leavens, G.T., & Ruby, C., Iowa State University Department of Computer Science Technical Report #TR98-06, June 1998.

"Programming as Writing: Why Programs Need to be Carefully Read", Baker, A.L., Leavens, G.T., LaValle, S.M., & Prabhu, G. Submitted to Mathematics and Computer Education.

"Executing Formal Specifications with Constraint Programming," Wahls, T., Leavens, G.T., & Baker, A.L., submitted.

"Enhancing the Pre- and Postcondition Technique for More Expressive Specifications", Baker, A.L., & Leavens, G.T. Iowa State University Department of Computer Science Technical Report #TR97-19, September 1997.

"Testing SPECS-C++: A First Step in Validating Distributed Systems Specification," Baker, A.L., & Gurski, M. Proceedings of the ISMM International Conference on Intelligent Information Management Systems, Washington, D.C., June 1997, pp. 105-108.

"Modelling and Simulating Computer Networks Using Formalized Data flow Diagrams," Baker, A.L., & Haverdink, M. IASTED International Conference on Modelling and Simulation, May 1997.

"Formalized Data Flow Diagrams and Their Relation to Other Computational Models", Baker, A.L., Iowa State University Department of Computer Science Technical Report #TR96-23, April 1997.

"Synthesizing Structured Analysis and Object-Based Formal Specifications," Baker, A.L., & Coleman, D.L. (1997). Annals of Software Engineering, 3: 221-254.

"Content Analysis and Natural Language Data Base Systems," Baker, A.L., (1997). Invited chapter in Text Analysis for the Social Sciences: Methods for Drawing Statistical Inferences from Texts and Transcripts, C. Roberts ed., Lawrence Ehrlbaum and Associates.

"Timed Data Flow Diagrams," Baker, A.L., & Symanzik, J., Iowa State University Department of Computer Science Technical Report #TR96-23.

"Formal Semantics for Structured Analysis Style Data Flow Diagram Specification Languages," Baker, A.L., Leavens, G.T., & Wahls, G., Iowa State University Department of Computer Science Technical Report #TR96-16.

B.S. 1969, Physics, University of Florida

M.S. 1976, Computer Science, Iowa State University

Ph.D. 1979, Computer Science, Iowa State University

Instructional use of computers, programming languages, object-oriented programming.

Current research involves the development of instructional applications for the Internet. Projects include Java Instructional simulations in meterology and mathematics and the ClassNet system which is a database system for the management of Web-based instructional classes.

"ClassNet: Managing the Virtual Classroom" Boysen, P., & Van Gorp, M., (1997). International Journal of Educational Telecommunications, 3(2/3):279-292.

"Reducing Object Storage Requirements in a Multi-user Environment," Boysen, P., & Shah, P., Software-Practice and Experience, 23(3):255-241, March 1993.

"Using Simulations to Fill Instructional Gaps," Boysen, P., & Thomas, R. EDU, 40:8-11, Winter 1986.

"A Taxonomy for the Instructional Use of Computers," Boysen, P., & Thomas, R., AEDS Monitor, 22(11):12, May/June 1984.

"An Evaluation of the Instructional Effectiveness of a Computer Lesson in Biomechanics," Boysen, P., & Francis, P. (1982). Research Quarterly for Exercise and Sport, 53(3):232-235.

"Them Bones: The Use of Computer-Assisted Instructional Techniques in the Teaching of Human Anatomy," Boysen, P., Francis, P., Ciskey, M., & Seastrand, P. The Computing Teacher, 9(3):11-16, November 1981.

"Measuring Computer Program Comprehension," Boysen, P., & Keller, R. ACM SIGCSE Bulletin, 12:92-102, February 1980.

"A Cost-Effective Method for the Reduction and Analysis of Film Data Using the PLATO System" Boysen, P., & Francis, P. (1978). Journal of Biomechanics, 11:343-345.

"Interactive Computer Graphics in the Study of Human Body Planar Motion Under Free Fall Conditions," Boysen, P., Francis, P., & Thomas, R. (1997). Journal of Biomechanics, 10:783-788.

B.S. 1984, Computer Science and Mathematics, Massachusetts Institute of Technology

M.S. 1987, Computer Science, University of Washington, Seattle

Ph.D. 1990, Computer Science, University of Washington, Seattle

Theory of Distributed Computing, Parallel Algorithms and Complexity Theory.

The Power of Inexact Timing Information in Distributed Systems

Dr. Chaudhuri’s research in distributed computing has focused on understanding the power of asynchronous distributed systems subject to various kinds of failures. A persistent question has been to determine the problems that are solvable in the presence of uncertainty due to processor asynchrony and failures. She used combinatorial techniques to prove that certain problems are impossible to solve in these systems. The current focus of her research has shifted to the study of systems that are semi-synchronous, i.e., that have partial but inexact information about timing. These systems are much more realistic and deserve further study. Dr. Chaudhuri intends to use similar combinatorial techniques with the goal of obtaining time and space complexity characterizations for problems in semi-synchronous systems analogous to the fault-resiliency characterization obtained for problems in asynchronous systems.

The main goal in this research is to understand the power of making inexact timing assumptions in solving the canonical problems in distributed computing. Dr. Chaudhuri will be studying some of the same questions that have been previously studied, but in the context of certain timing assumptions. One goal of the research would be to develop general techniques which permit simulation of arbitrary synchronous (possibly round-based) fault-tolerant algorithms for various problems in the model with timing uncertainty. At a more abstract level, Dr. Chaudhuri would like to develop novel techniques for exploiting timing assumptions in both algorithm design and in obtaining lower bounds and impossibility results. A second goal would be to develop a complexity hierarchy of shared objects in a timing-based distributed system. The ultimate objective would be to understand in a formal sense the advantage that can be gained by considering timing-based models for distributed computing over asynchronous models, and the disadvantage they represent in relation to fully synchronous models.

"Wait-Free Implementations in Message Passing Systems." Chaudhuri, S., Herlihy, M., & Tuttle, M. (1998). To appear in Theoretical Computer Science.

"Shared Memory Consistency Conditions for Non-Sequential Execution: Definitions and Programming Strategies," Chaudhuri, S., Attiya, H., Friedman, R., & Welch, J.L. To appear in SIAM Journal on Computing, 27(1), February 1998.

"One-Write Algorithms for Multi-Valued Regular and Atomic Registers," Chaudhuri, S., Kosa, M., & Welch, J.L. (1998). To appear in Acta Informatica.

"Understanding the Set Consensus Partial order Using the Borowsky-Gafni Simulation," Chaudhuri, S., & Reiners, P. Proceedings of the Tenth International Workshop on Distributed Algorithms, 1996. Lecture notes in Computer Science 1151, Springer-Verlag, pp. 362-379.

"Using Adaptive Timeouts to Achieve At-Most-Once Message Delivery," Chaudhuri, S., Coan, B., & Welch, J. Distributed Computing, 9(3):109-117, September 1995.

"Bounds on the Costs of Multi-Valued Register Implementations," Chaudhuri, S., & Welch, J. SIAM Journal on Computing, 23(2):335-354, April 1994.

"A Tight Lower Bound for Set Agreement," Chaudhuri, S., Herlihy, M., Lynch, N., & Tuttle, M. Proceedings of the 34^th Annual IEEE Symposium on Foundations of Computer Science, November 1993, pp. 206-215.

"More Choices Allow More Faults: Set Consensus Problems in Totally Asynchronous Systems," Chaudhuri, S. Information and Computation, 105(1):132-158, July 1993.

"Safety and Liveness of Context-Free Languages," Chaudhuri, S., & Ladner, R.E. Information Processing Letters, 37(10):13-20, January 1991.

"Graph Bisection Algorithms With Good Average Case Behavior," Chaudhuri, S., Bui, T., Leighton, T., & Sipser, M. (1987). Combinatorica, 7(2):171-191.

B.S. 1980, Electrical & Computer Engineering, National University of Mexico, Mexico City

M.S. 1983, Electrical & Computer Engineering, University of California, Davis

Ph.D. 1986, Computer Science, University of California, Davis

Design and analysis of algorithms, combinatorial optimization, graph algorithms, computational geometry, computational biology.

Dr. Fernandez-Baca conducts research in the design and analysis of combinatorial algorithms. One of his main areas of activity is parametric optimization, where his goal is to design efficient algorithms to analyze the sensitivity of the optimum solution to changes in the input data. Computational biology is another field to which Dr. Fernandez-Baca has devoted his attention; in particular he has studied some of the combinatorial problems arising in the reconstruction of evolutionary trees for sets of species. Some of this work has been applied to the study of the evolution of human languages. Dr. Fernandez-Baca is also investigating geometric problems arising in robotics and manufacturing.

"Optimal Parametric Search in Graphs of Bounded Tree-width," Fernandez.-Baca, D., & Slutzki, G. (1997). Journal of Algorithms, 22:212-240.

"Using Sparsification for Parametric Minimum Spanning Tree Problems," Fernandez-Baca, D., Slutzki, G., & Eppstein, D. (1996). Proceedings of the 5^th Scandinavian Workshop on Algorithm Theory, pp. 194-160, Springer-Verlag Lecture Notes in Computer Science, 1097.

"Weighted Multidimensional Search and its Application to Convex Optimization," Fernandez-Baca, D., & Agarwala, R. (1996). SIAM Journal on Computing, 25:83-99.

"Simple Algorithms for Perfect Phylogeny and Triangulating Colored Graphs," Fernandez-Baca, D., & Agarwala, R. International Journal of Foundations of Computer Science (invited paper to special issue on Computational Biology), 7(1):11-21, March 1996.

"A Polynomial-Time Algorithm for Near-Perfect Phylogeny," Fernandez-Baca, D., & Lagergren, J. (1996). Proceedings of the 23^rd International Colloquium on Automata, Languages, and Programming, pp 670-680, Springer-Verlag Lecture Notes in Computer Science.

"Linear-time Algorithms for Parametric Minimum Spanning Tree Problems on Planar Graphs," Fernandez.-Baca, D., and Slutzki, G. In Proceedings of the Latin American Conference on Theoretical Informatics, pp. 257-271, LNCS 911, Springer-Verlag, 1995. To appear in Theoretical Computer Science.

"Fast Algorithms for Computing Evolutionary Trees," Fernandez-Baca, Agarwala, R., & Slutzki, G. (1995). Journal of Computational Biology, 2(3):397-408.

"A Polynomial-Time Algorithm for the Perfect Phylogeny Problem when the Number of Character States is Fixed," Fernandez-Baca, D., & Agarwala, R. (1994). SIAM J. Computing, 23:1216-1224.

"Parametric Problems on Graphs of Bounded Tree-width," Fernandez.-Baca, D., & Slutzki, G. (1994). Journal of Algorithms, 16:408-430.

"Solving Parametric Problems on Trees," Fernandez.-Baca, D., & Slutzki, G. (1989). Journal of Algorithms, 10:381-402.

B.S. (Hons), 1969, Mathematics, Birla Inst. of Tech. & Science

M.Sc. 1970, Mathematics, Birla Inst. of Tech. & Science

Ph.D. 1977, Mathematics, University of Illinois

M.S. 1980, Computer Science, Ohio State University

Temporal, spatial, belief, security, statistical and incomplete data; database models, type hierarchy, languages, user interfaces, optimization, implementation and access methods; pattern matching in spatio-temporal data.

The term dimensional data covers databases for data over a dimensional space such as time, space and user beliefs. A uniform approach for dimensional data assures upward compatibility. Thus when one migrates from lower forms of dimensional data to higher forms, e.g. ordinary data to spatio-temporal data, the existing application software would not need to be redeveloped. Such a framework necessitates careful study of pragmatic issues such as database optimization.

"A Pattern Matching Language for Spatio-Temporal Databases," Gadia, S., & Cheng, T. (1994). Proceedings of the Third International Conference on Information and Knowledge Management, pp. 288-295.

"Object Identity and Dimension Alignment in Parametric Databases," Gadia, S., Cheng, T. & Nair, S. (1993). Proceedings of the Second International Conference on Information and Knowledge Management, pp. 615-624.

"Relational Database Systems With Zero Information-Loss," Gadia, S., & Bhargava, G. (1993). IEEE Transactions on Knowledge and Data Engineering, 5:76-87.

"Incomplete Information in Relational Temporal Databases," Gadia, S., Nair, S., & Poon, Y. (1992). Proceedings of the 18th International Conference on Very Large Databases, pp. 395-406.

"Algebraic Optimization in a Relational Model for Temporal Databases," Gadia, S., & Nair, S. (1992). Proceedings of the First International Conference on Information and Knowledge Management, pp 169-176.

"A Generalized Model for a Relational Temporal Database," Gadia, S., & Yeung, C. (1988). ACM SIGMOD Conference on Management of Data, pp. 251-259.

"A Homogeneous Relational Model and Query Languages for Temporal Databases," Gadia, S. (1988). ACM Transactions on Database Systems, 14:418-448.

"A Query Language for a Homogeneous Temporal Database," Gadia, S., & Vaishnav, J. (1985). Proc. Fourth Annual ACM SIGACT-SIGMOD Symposium on Principles of Database Systems, pp 51-56.

B.S. 1971, Mathematics, Carnegie Mellon University

Ph.D. 1977, Computer Science, Carnegie Mellon University

Numerical Analysis, Parallel Computation, Computer Architecture (technology-oriented algorithm design and analysis). Programming and debugging support tools for distributed memory systems, performance evaluation and analysis.

"A Communication Library Using Active Messages to Improve Performance of PVM," Subramaniam, K.R., Kothari, S.C., & Heller, D. (1996). Journal of Parallel and Distributed Computing, 39:146-152.

"Issues of Running Code on Very Large Parallel Processing Systems," Heller, D. (1996). Debugging and Performance Tuning for Parallel Computer Systems, M.L. Simmons et al., eds., IEEE Computer Society.

"Gordon Bell Prize Lectures 1993," Heller, D. Proc. Supercomputing '93, pp. 514-515. Summary articles in IEEE Computer, Jan. 1994, pp. 69-75, and Jan. 1995, pp. 68-74.

"Ten Steps for Managing Parallel Computing Projects," Heller, D. IEEE Parallel and Distributed Technology, Spring 1994, pp. 6-8.

"Performance Measurements of the nCUBE/ten Multiprocessor," Heller, D. Shell Development Co., Houston, December 1988.

"Partitioning Big Matrices for Small Systolic Arrays," Heller, D. (1985). VLSI and Modern Signal Processing" S.Y. Kung et al., eds., Prentice-Hall, pp. 185-199.

"Mathematical Hardware - Design Issues and Responsibilities," Heller, D. (1985). Algorithmically Specialized Parallel Computers, L. Snyder et al., eds., Academic Press, pp. 233-241.

"Systolic Networks for Orthogonal Decompositions," Heller, D., & Ipsen, I.C.F., (1983). SIAM J. Sci. Stat. Computing, 4:261-269.

"Minimal Parallelism for Associative Computations Under Time Constraints," Heller, D. (1979). Computing, 22:101-118.

"A Survey of Parallel Algorithms in Numerical Linear Algebra," Heller, D. (1978). SIAM Review, 20:740-777.

B.E. 1982, Electronics Engineering, Bangalore University, India.

M.S. 1984, Electrical and Computer Engineering, Drexel University

M.S. 1989, Computer Science, University of Wisconsin at Madison

Ph.D. 1990, Computer Science and Cognitive Science, University of Wisconsin at Madison

www: http://www.cs.iastate.edu/~honavar/honavar.html

Artificial Intelligence; Artificial Neural Networks; Autonomous Robots; Automata Induction; Biological Computation; Bioinformatics and Computational Biology; Cognitive Science; Complex Adaptive Systems; Computational Learning Theory; Computational Neuroscience; Data Mining and Knowledge Discovery; Decision Support Systems; Distributed Knowledge Networks; Distributed Databases, Mediators, and Data Warehouses; Evolutionary Computation; Intelligent Agents, Mobile Agents,and Multi-Agent Systems; Intelligent Design and Manufacturing Systems; Internet-Based Information Systems; Knowledge Representation, Automated Inference, and Knowledge-Based Systems; Machine Learning; Machine Perception; Parallel and Distributed Artificial Intelligence.

Examples of current projects in Honavar's laboratory on Intelligent Agents, Mobile Agents, and Multi-Agent Systems include Distributed Knowledge Networks for information retrieval, extraction, and organization; and data-driven knowledge discovery and theory refinement using heterogeneous, distributed knowledge and data sources with emphasis on Bioinformatics and Situation Assessment and Decision Support applications. In related work, topics in mobile agents, inter-agent negotiation protocols, rapid design and prototyping of intelligent agents, distributed problem solving, and coordination and control structures for multi-agent systems are being investigated.

Current research in Honavar's lab in machine learning emphasizes the design, analysis, and implementation of algorithms for automata induction, neural networks for pattern recognition, feature subset selection, incremental data driven theory refinement, spatial and temporal knowledge acquisition, and multi-task learning with emphasis on applications in bioinformatics, large scale data mining and knowledge discovery from structured, semi-structured, and unstructured data and knowledge sources, domain-specific automated program synthesis, decision support, customizable digital information assistants, diagnosis, intrusion detection, power system security assessment, and related areas.

Current research in Computational Neuroscience is focused on algorithmic models of memory and learning with emphasis on acquisition and use of spatial maps. Current research in Computational Biology emphasizes tools for gene discovery, protein structure prediction with emphasis on plant genomics.

Honavar's research has been partially supported by grants from the National Science Foundation, the John Deere Foundation, IBM, Carver Foundation, ISU Council on International Relations, and the ISU graduate college.

"Intelligent Diagnosis Systems," Balakrishnan, K., & Honavar, V. (1998). Journal of Intelligent Systems. In press.

"Spatial Learning and Localization in Animals: A Computational Model and its Implications for Mobile Robots," Balakrishnan, K., Bousquet, O. & Honavar, V. (1998). Adaptive Behavior. In press.

"A Computational Model of Rodent Spatial Learning and Some Behavioral Experiments," Balakrishnan, K., Bhatt, R., & Honavar, V. (1998). In: Proceedings of the Twentieth Annual Meeting of the Cognitive Science Society. Madison, WI.

"A Neural Architecture for Syntax Analysis," Chen, C.-H., & Honavar, V. (1998). IEEE Transactions on Neural Networks. In press.

"Neural Architecture for Information Retrieval and Query Processing," Chen, C-H., & Honavar, V. (1998) Invited Chapter in: Handbook of Natural Language Processing. Dale, Moisl and Somers (Ed). New York: Marcel Dekker. In press.

"Distributed Knowledge Networks: Design, Implementation, and Applications," Honavar, V., Miller, L., & Wong, J. (1998). In Proceedings of the IEEE Information Technology Conference. In press.

"Intelligent Agents," Honavar, V. (1998). Invited chapter in Encyclopedia of Information Technology. Williams, J.G. and Sochats, K. (ed). New York: Marcel Dekker. To appear.

"Inductive Learning: Principles and Applications," Honavar, V. (1998).. Invited chapter in Intelligent Data Analysis in Science. Cartwright, H. (Ed). New York: Oxford University Press. To appear. 1998.

"Machine Learning," Honavar, V. (1998). Invited article in Wiley Encyclopedia of Electrical and Electronic Engineering. Webster, J. (Ed). New York: Wiley. In press.

"Constructive Theory Refinement in Knowledge based Neural Networks," Parekh, R., & Honavar, V. (1998). Proceedings of the International Joint Conference on Neural Networks. Anchorage, Alaska.

"Automata Induction, Grammar Inference, and Language Acquisition," Parekh, R. & Honavar, V. (1998). Invited chapter in Handbook of Natural Language Processing, Dale, Moisl and Somers (Ed). New York: Marcel Dekker. In press.

Feature Subset Selection Using a Genetic Algorithm. Yang, J. & Honavar, V. (1998). IEEE Intelligent Systems. 13:44-49.

"DistAl: An Inter-Pattern Distance Based Constructive Neural Network Learning Algorithm," Yang, J. & Honavar, V. (1998). Intelligent Data Analysis. In press.

"Mobile Intelligent Agents for Document Classification and Retrieval: A Machine Learning Approach." Yang, J., Pai, P., Honavar, V., & Miller, L. (1998). In Proceedings of the European Symposium on Cybernetics and Systems Research..

"Learning DFA from Simple Examples." Parekh, R.G. & Honavar, V. (1997). Proceedings of the International Workshop on Algorithmic Learning Theory. (ALT 97). Sendai, Japan.

"Analysis of Utility-Theoretic Heuristics for Intelligent Adaptive Network Routing," Mikler, A., Honavar, V., & Wong, J., (1996). Proceedings of the Thirteenth National Conference on Artificial Intelligence (AAAI-96). San Diego: AAAI Press. 1:96-101 (1996).

B.S. 1970, Mathematics, Poona University, India

M.S. 1972, Mathematics, Poona University, India

Ph.D. 1977, Mathematics, Purdue University

Parallel and Distributed Processing, Computer Architecture, Performance of Computer Systems, Inverse problems.

The objective of the research is to advance software technology for parallel and distributed computing. Dr. Kothari is currently working on two projects: 1) Parallelization Agent, 2) BATRUN Distributed Processing System. Paralleli-zation agent is a system for automatic conversion from serial to parallel code using a structured parallelization process based on class-specific abstractions of underlying numerical methods. BATRUN is a distributed processing system running on Unix and Windows NT platforms. The activities include development in this area of the new techniques for semi-automatic generation of parallel codes, modeling and designing of software systems for parallel and distributed environments, and development of prototype systems. The experimental work is carried out on a variety of computing platforms including several parallel machines and a cluster of workstations.

His other area of interest is neural networks, MARS (Multivariate Adaptive Regression Splines), and other techniques for solving inverse problems in signal processing applications.

"Parallelization Agent: A New Approach for Parallelizing Legacy Codes," Kothari, S.C. 8^th SIAM Conference on Parallel Processing, March 1997.

"Parallel Implementation of Hydrostatic MM5," Kothari, S.C. 8^th SIAM Conference on Parallel Processing, March 1997.

"A Communication Library Using Active Messages to Improve Performance of PVM." Kothari, S.C. Journal of Parallel and Distributed Computing, 39:146-152, December 1996.

"Batrun: Utilizing Idle Workstations for Large-Scale Computing," Kothari, S.C. IEEE Parallel and Distributed Technology, Summer 1996, 4-2:41-49.

"Adaptation of the Relaxation Method for Learning in Bidirectional Associative Memory," Kothari, S.C. (1994). IEEE Transactions on Neural Networks, 5-4.

"Neural Networks for Pattern Recognition," Kothari, S.C. Advances in Computers, 37:119-165, May 1993.

"Optimal Parallelization of Sorting Networks," Kothari, S.C. (1990). Theoretical Computer Science Journal, 76:331-341.

"Optimal Design of Systolic Architecture," Kothari, S.C. (1989). Proceedings of International Conference on Parallel and Distributed Processing, pp. 247-256.

B.S. 1990, Computer Engineering, University of Illinois at Urbana-Champaign

M.S. 1993, Electrical Engineering, University of Illinois at Urbana-Champaign

Ph.D. 1995, Electrical Engineering, University of Illinois at Urbana-Champaign

Robotics, computer vision, artificial intelligence, geometric motion planning, visibility analysis, stochastic analysis, dynamics, applied optimal control, dynamic game theory, practical modeling and computational issues in applications such as mobile robotics, graphical animation, and pharmaceutical drug design.

These are exciting times as computer science and related engineering areas are rapidly advancing, leading to many new modeling challenges, paradigms for analysis, and opportunities to make contributions in emerging applications. Dr. LaValle’s current interests lie in the algorithmic, modeling, and analysis issues involved at the intersections of geometric reasoning, modern planning/control, and uncertainty, and his background is built on combinations of subjects from computer science (e.g., algorithms, computational geometry), electrical engineering (e.g., control, image processing), and applied math (e.g., probability, analysis, topology).

Most of the research of Dr. LaValle’s group is conducted in the Algorithmic Robotics and Motion Strategy Lab, which contains several PC-based workstations and a Nomad XR4000 mobile robot base. This state-of-the-art robotics platform (only 20 currently exist in the world) enables the group to perform a wide array of experiments due to its powerful features, such as a color PCI vision system, radio Ethernet, on-board Pentium II running Linux, and a holonomic drive mechanism. Their current mobile robotics interests include target location and tracking, mobile manipulation, and network-based tele-embodiment.

Dr. LaValle also works on the design and implementation of several types of algorithms that can be used in geometry-oriented applications such as robotics, virtual prototyping, computer graphics, and rational drug design. He is particularly interested in computing collision-free trajectories and feedback motion strategies for problems that involve nonholonomic constraints, dynamics, visibility-analysis, sensing uncertainty, or closed kinematic chains.

Some of his work is conducted in collaboration with researchers at Stanford University and Rice University.

"Numerical Computation of Optimal Navigation Functions on a Simplicial Complex," LaValle, S.L. To appear in Algorithmic Foundations of Robotics III, Proc. 3rd Int'l Workshop on the Algorithmic Foundations of Robotics. A. K. Peters, Boston, MA.

"Visibility-Based Pursuit-Evasion in a Polygonal Environment," LaValle, S., Guibas, L.J., Latombe, D.J., Lin, D., & Motwani, R., International Journal of Computational Geometry and Applications.

"An Objective-Based Framework for Motion Planning under Sensing and Control Uncertainties," LaValle, S., & Hutchinson, S. A. International Journal of Robotics Research, 17(1):19-42, January 1998.

"Motion Strategies for Maintaining Visibility of a Moving Target." LaValle, S., Gonzalez-Banos, H.H., Becker, C., & Latombe, J.C., in Proc. 1997 IEEE International Conference on Robotics and Automation.

"Robot Motion Planning: A Game-Theoretic Framework," LaValle, S. (1997). Algorithms for Robotic Motion and Manipulation, J.P. Laumond and M. Overmars, Eds., A.K. Peters, Boston, MA.

"On Motion Planning in Changing, Partially-Predictable Environments," LaValle, S., & Sharma, R., International Journal of Robotics Research, 16(6), 775-805, December 1997.

"Optimal Motion Planning of Multiple Robots Having Independent Goals." LaValle, S., & Hutchinson, S. A., to appear in IEEE Trans. on Robotics and Automation.

"Methods for Numerical Integration of High-Dimensional Probability Densities with Application to Statistical Image Models," LaValle, S., Moroney, K.J., & Hutchinson, S.A., IEEE Transactions on Image Processing, 6(12), 1659-1672, December 1997

"Optimizing Robot Motion Strategies for Assembly with Stochastic Models of the Assembly Process," LaValle, S., Sharma, R., & Hutchinson, S.A., in IEEE Trans. on Robotics and Automation, Special issue on Assembly and Task Planning for Manufacturing, 12(2), 160-174, April 1996.

"A Framework for Constructing Probability Distributions on the Space of Segmentations," LaValle, S., & Hutchinson, S.A., in Computer Vision and Image Understanding, 61(2), 203-230, March 1995.

B.S. 1978, Computer & Communication Sciences, The University of Michigan

M.S. 1980, Computer Science, The University of Southern California

Ph.D. 1989, Computer Science, Massachusetts Institute of Technology

Programming and specification language design and semantics, formal methods (program specification and verification), object-oriented programming, functional programming, type theory, programming methodology, distributed programming languages.

The long term goal of my research is to understand better how to solve programming problems: how to specify such problems, methods for thinking about such problems, notations for expressing solutions, and ways to check that the solutions are correct. In pursuing this goal, I have worked in two main areas: formal methods and programming languages.

Formal Methods: My work in formal methods has been focused on ways to specify and verify object-oriented (OO) software components. This specification work involves the design and formal description of a behavioral interface specification language for C++ programs, called Larch/C++. >From this work a key problem has emerged: how to make specification languages that are expressive enough for documenting existing code in ways that people will find helpful for reuse. We have made some progress with Larch/C++ towards solving this problem, but there is a lot of information that it cannot (yet) record. Examples include information about performance constraints, and details needed for deriving subclasses by inheritance. Our current work on a Java specification language, funded by Rockwell and the National Science Foundation (NSF) tries to address some of these issues. This recent work is joint with Professor Al Baker.

An advantage of OO languages, such as C++ and Java, is that their message passing mechanism allows one to easily extend programs by adding new types whose objects behave like the objects of existing types; the existing types are supertypes of the new types which are called subtypes. A long term research interest has been to understand how to reason about programs that use subtyping and message passing. A criteria for judging specification and verification methods is that they should be modular in the sense that when subtypes are added to a program, unchanged modules would not have to be respecified or reverified. Modular reasoning is guaranteed by the technique of supertype abstraction. In this technique, one specifies and verifies code in terms of the static types of expressions written in a program (as usual), uses a type checker to ensure that the static types are supertypes of the run-time types, and then must prove that subtypes obey the specifications of their supertypes.

Krishna Kishore Dhara, a recently graduated Ph.D. student, has extended the formal theory of behavioral subtyping to types whose instances have time-varying state. Professor Don Pigozzi (of the Mathematics Department at ISU) and I have found an exact algebraic characterization of behavioral subtyping for immutable types. Our joint research on the above topics has been funded by the National Science Foundation (NSF). A former Ph.D. student, Yoonsik Cheon, has also designed a specification language Larch/Smalltalk and its informal semantics to explore some of these ideas. I have also been working with Professor Al Baker and a former Ph.D. student, Tim Wahls, on executable specifications and improving syntax and semantics of data-flow diagrams.

The potential impact of the work in formal methods is possibly great; it might lead to the engineering of software, instead of hacking. It also seems necessary for high quality software components and reuse. But more realistically, I view my research as trying to formally understand what one needs to think about when documenting and reasoning about a program or program component. This can be of great value for teaching and for the construction of tools, even if people do not use the formalism directly or on a daily basis.

Programming Language Design and Semantics: The other main aspect of my work in the last few years has been on the design and semantics of object-oriented languages with generic functions. Such languages are known as multimethod programming languages, because method calls can dispatch a message send on all arguments, unlike a single-dispatching OO language, such as Smalltalk, C++, or Java. Multimethod languages are interesting because they can more easily express solutions to certain problems in OO programming (binary methods).

My work on multimethod languages is joint with Craig Chambers of the University of Washington, his student Todd D. Millstein as well as Sevtap Karakoy, Jianbing Chen, and Professors Al Baker and Don Pigozzi of ISU. It focuses on the semantics and type systems for variants of the Cecil language. To date we have published papers about an algorithm for type checking such languages with very expressive features (orthogonal inheritance and subtyping). One big unsolved problem we are working on is to get a language with both a (sound) static type system and a sensible module system. We have designed a langauge allows one to program abstract data types in two styles, one of which is easier to extend (as in standard OO languages) and the other of which is easier to reason about. Programmers can use both styles in the same program. The potential impact might be large if this leads to more flexible ways of supporting abstract data types in programming languages, as they are at the heart of modular, reusable coding practices. A recent NSF is starting to fund research on formal methods for such languages.

Details are available through my selection of representative publications below and through my other WWW pages.

"The Behavior-Realization Adjunction and Generalized Homomorphic Relations." Leavens, G.T., & Pigozzi, D. (1997). Theoretical Computer Science, 177:183-216.

"An Overview of Larch/C++: Behavioral Specifications for C++ Modules." Leavens, G.T. In Haim Kilov and William Harvey (editors), Specification of Behavioral Semantics in Object-Oriented Information Modeling (Kluwer Academic Publishers, 1996), Chapter 8, pp. 121-142. An extended and up-to-date version is Department of Computer Science, Iowa State University, TR #96-01d, February 1996, revised March, April 1996, January, July 1997.

"Forcing Behavioral Subtyping Through Specification Inheritance." Dhara, K.K., & Leavens, G.T. In Proceedings 18th International Conference on Software Engineering, Berlin, Germany, pages 258-267. IEEE, 1996. An extended and slightly revised version is Department of Computer Science, Iowa State University, TR #95-20c, August 1995, revised August and December 1995, March 1997.

Specification and Verification of Object-Oriented Programs Using Supertype Abstraction. Leavens, G.T., & Weihl, W.E. Acta Informatica, 32(8):705-778, November 1995.

"On Binary Methods." Kim B. Bruce, Luca Cardelli, Giuseppe Castagna, The Hopkins Objects Group, Leavens, G.T., & Pierce, T. (1995). Theory and Practice of Object Systems 1(3):221-242.

"Typechecking and Modules for Multimethods," Chambers, C., & Leavens, G.T. ACM Transactions on Programming Languages and Systems, 17(6):805-843, November 1995.

"The Larch/Smalltalk Interface Specification Language." Cheon, Y. & Leavens, G.T. ACM Transactions on Software Engineering and Methodology, 3(3):221-253, July 1994.

"Modular Specification and Verification of Object-Oriented Programs." Leavens G.T., IEEE Software, 8(4):72-80, July 1991.

"Typed Homomorphic Relations Extended with Subtypes." Leavens, G.T., & Pigozzi, D. In Stephen Brookes, editor, Mathematical Foundations of Programming Semantics '91, pages 144-167. Volume 598 of Lecture Notes in Computer Science. Springer-Verlag, 1992.

"Reasoning about Object-Oriented Programs that use Subtypes" (extended abstract). Leavens, G.T., & Weihl, W.E. In OOPSLA ECOOP '90 Proceedings, pp. 212-223 (25:10 of ACM SIGPLAN Notices, October 1990).

B.G.S. 1976, Mathematics, University of Kansas

M.A. 1979, Mathematics, University of Kansas

M.S. 1981, Computer Science, University of Kansas

Ph.D. 1987, Mathematics, California Institute of Technology

Computational complexity, including resource-bounded measure, structure of complexity classes, probabilistic complexity, quantum complexity, uniform versus nonuniform complexity, and the complexity of real-valued functions. Algorithmic randomness, Kolmogorov complexity, and computational depth.

Dr. Lutz does most of his research in two areas: computational complexity theory and algorithmic information theory. In computational complexity, he and his students are investigating the structure of complexity classes (deterministic, nondeterministic, probabilistic, and quantum) using resource-bounded measure, a complexity-theoretic generalization of Lebesgue measure that he has developed. Current work focuses on weak completeness, circuit-size complexity, natural proofs, genericity, interactions between randomization and nondeterminisim, strong hypotheses, real-valued functions, and the foundations of resource-bounded measure. In algorithmic information, he and his students are investigating randomness, resource-bounded randomness, Kolmogorov complexity, algorithmic prediction, feasible martingales, and computational depth.

"The Quantitative Structure of Exponential Time," Hemaspaandra, L.A., Lutz, J.L., & Selman, A.L. (eds.), Complexity Theory Retrospective II, Springer-Verlag, 1997, to appear.

"Completeness and Weak Completeness under Polynomial-Size Circuits," Juedes, D., & Lutz, J. (1996). Information and Computation, 125:13-31.

"The Complexity and Distribution of Hard Problems," Juedes, D., & Lutz, J. (1995). SIAM Journal on Computing 24:279-295.

"Weakly Hard Problems," Lutz, J. (1995). SIAM Journal on Computing, 24:1170-1189.

"Computational Depth and Reducibility," Juedes, D., Lathrop, J., & Lutz, J. (1994). Theoretical Computer Science, 132:37-70.

"Measure, Stochasticity, and the Density of Hard Languages," Lutz, J., & Mayordomo, E. (1994). SIAM Journal on Computing, 23:762-779.

"On Languages with Very High Space-Bounded Kolmogorov Complexity," Book, R., & Lutz, J. (1993). SIAM Journal on Computing, 22:395-402.

"A Pseudorandom Oracle Characterization of BPP," Lutz, J. (1993). SIAM Journal on Computing, 22:1075-1086.

"Almost Everywhere High Nonuniform Complexity," Lutz, J. (1992). Journal of Computer and System Sciences, 44:220-258.

"Category and Measure in Complexity Classes," Lutz, J. (1990). SIAM Journal on Computing, 19:1100-1131.

B.A. 1974, English, University of Kansas

M.A. 1976, Spanish, University of Kansas

Ph.D. 1980, Spanish, University of Kansas

M.S. 1990, Computer Science, Iowa State University

Software safety, fault detection and recovery, requirements engineering, formal methods, software engineering for spacecraft.

Current research involves the integration of software and system safety techniques, the safety analysis of product lines, and the reuse of formally specified and verified models of fault-handling software on spacecraft.

"Failure Modes and Effects Analysis," Lutz, R., & Woodhouse, R. Encyclopedia of Electrical and Electronics Engineering, ed. J. Webster, John Wiley and Sons Publishers, to appear.

"Safety Analysis of Requirements for a Product Family," Lutz, R., Helmer, G., Moseman, M., Statezni, D., & Tockey, S. Proceedings of the Third IEEE International Conference on Requirements Engineering, April 6-19, 1998, Colorado Springs, CO.

"Experiences Using Lightweight Formal Methods for Requirements Modeling," Ampo, Y., Covington, R., Easterbrook, S., Hamilton, D., Kelly, J.,& Lutz, R., IEEE Transactions on Software Engineering, 24(1):4-14, January 1998.

"Reuse of a Formal Model for Requirements Validation," Lutz, R. Proceedings of the Fourth NASA Langley Formal Methods Workshop, 10-12:75-85, September 1997, Hampton, VA.

"Requirements Analysis Using Forward and Backward Search" Lutz, R., & Woodhouse, R. (1997). Annals of Software Engineering, Special Volume on Requirements Engineering, 3:459-475.

"Targeting Safety-Related Errors During Software Requirements Analysis," The Journal of Systems and Software, 34:223-230, September 1996.

"Detecting Unsafe Error Recovery Schedules" Lutz, R., & Wong, J. IEEE Transactions on Software Engineering, 18(8):749-760, August 1992.

B.A. 1967, Mathematics, University of South Dakota

M.A. 1974, Mathematics, University of South Dakota

Ph.D. 1980, Computer Science, Southern Methodist University

Object oriented databases, Organizational decision support systems, Database semantics, Database design, Data warehouses, Computational Biology.

We are currently looking at using our multidatabase views to define an object-oriented data warehouse. We have also been looking at design tools for generating data warehouse designs. We are also concerned with applying database and machine learning techniques to problems in computational biology.

"Data Warehouse Modeler: A Case Tool for Warehouse Design," Miller, L.L., & Nilakanta, S.. (1998). Hawaiian International Conference on Systems Science, pp. 42-48.

"Extending the Object-Relational Interface to Support an Extensible View System for Multidatabase Integration and Interoperation," Miller, L.L., Yen, D., Sirjani, A., & Tenner, J. (1998). International Journal of Computer Systems Science and Engineering.

"A Dynamic Approach for Finding the Join Sequence in a Universal Relation Interface," Miller, L.L., & Owrang, M. M. (1998). To appear in the Journal of Integrated Computer-Aided Engineering, 4:310-318.

"Warehousing Structured and Unstructured Data for Data Mining." Miller, L.L., Honavar, V., & Barta, T. (1997). ASIS ’97, pp. 215-224.

"A Real-time System for High Transaction Loads and Moderate Deadlines." Carr, D., Miller, L.L., & Smay, T. (1997). International Society for Computers and Their Applications 12^th Annual Conference, pp. 134-139.

"The Design and Development of an Organizational Memory System." Miller, L.L., & Nilakanta, S. (1997). Hawaiian International Conference on Systems Science, pp. 360-368.

"A Dynamic Cluster Scheme for Distributed Object Oriented Databases." Lim, J.B., Hurson, A.R., & Miller, L.L. (1997). The Proceedings of the Eleventh International Conference on Mathematical and Computer Modelling and Scientific Computing will appear in a special issue of Mathematical Modelling and Scientific Computing.

"An Extensible View System for Multidatabase Integration and Interoperation," Miller, L.L., & Yen, C. (1995). Integrated Computer-Aided Engineering, 2(2):97-123.

B.A. 1957, Mathematics, Oklahoma State University

M.S. 1959, Mathematics, Oklahoma State University

Ph.D. 1970, Computer Science, Purdue University

Operating systems, parallel processing, distributed processing, computer security.

Current research is focused on the development of a comprehensive model of computer and information systems security.

"An Access Control Language for Object-Oriented Programming Systems," Oldehoeft, A.E., & Mizuno, M. (1990). Journal of Systems and Software, (13):3-12.

"A Survey of Password Mechanisms: Weaknesses and Potential Improvements," Oldehoeft, A.E., & Jobusch, D. Journal of Computers and Security, Part I, November 1989, pp. 589-604, Part II, December 1989, pp. 675-689.

"Information Flow Control in a Distributed Object-Oriented System with Statically Bound State Variables," Oldehoeft, A.E., & Mizuno, M. (1987). Proceedings of the 10th National Computer Security Conference.

"Dataflow Resource Managers and Their Synthesis From Open Path Expressions," Oldehoeft, A.E., & Jennings, S. IEEE Transactions on Software Engineering, SE-10(3): 244-257, May 1984.

"A Software Scheme for User-controlled File Encryption," Oldehoeft, A.E., & McDonald, R. (1984). Computers and Security, (3): 35-41.

"The Use of Combinators in Translating Purely Functional Language to Low-level Dataflow Graphs," Oldehoeft, A.E., & Maurer, P. (1983). Computer Languages, 8(l):27-45.

"An Analysis of Program Execution of a Recursive Stream-Oriented Data Flow Architecture," Oldehoeft, A.E., & Jennings, S.F. (1983). Journal of Systems and Software, (3):147-154.

B.S. 1960, Statistics, Iowa State University

Applied systems technology; computer based information systems; data center management, large data bases, interactive systems; hardware/software and people synergism.

"Iowa State University’s Purchasing System: New Platform Leads to More Services, More Success," Ostendorf, W.O., Moats, L., & Diana, R. Proceedings of the 39th Annual College and University Computer Users Conference, pp. 61-76, Ohio State University, May 1994.

"Electronic Information - Image Processing: A Step Toward an Electronic Information Environment at Iowa State University," Ostendorf, W.O., & Newhouse, L. Proceedings of the 38th Annual College and University Computer Users Conference, May 1993, pp. 377-392.

"Customized Tools, CAAD System (Computer Aided Application Development)," Ostendorf, W.O., & Maly, F. Proceedings of the 1990 CAUSE National Conference, November 1990, pp. 481-485.

B.Tech. 1975, Electrical Engineering, I.I.T., Madras, India

M.Tech. 1978, Computer Science, I.I.T., Kanpur, India

Ph.D. 1983, Computer Science, Washington State University, Pullman

Parallel processing, computer architecture, business process modeling and analysis.

Dr. Prabhu's current research focuses on performance issues of parallel programs and methods for business transformation.

"Enterprise Integration: Art or Science?" Summer Conference of the Society for Enterprise Engineering, June 1995.

"Truly Distribution-Independent Algorithms for the N-Body Problem," Prabhu, G., Aluru, S., & Gustafson, J. Supercomputing ‘94, pp. 420-428.

"A Methodology for Business Transformation," Prabhu, G., Nilakanta, S., & Subramanian, A. (1994). Proceedings of the Third International Conference on Systems Integration, Brazil, pp. 403-411.

"The Use of Microcontrollers in Mechatronics Education," Prabhu, G., & Wright, C. (1994). Proceedings of the Workshop on Mechatronics Education, Stanford, pp. 72-77.

Programming languages: program analysis and optimization, domain-specific language design and implementation. Networks and Distributed Systems: network security, fault management, reliable distributed systems, open-distributed processing. Software Engineering: static debugging, object-oriented design, automated verification/validation.

Distributed systems and networking technologies are bringing about fundamental changes in the way commercial, educational and political activities are conducted. As our lives depend increasingly upon networks and distributed information systems, it is critical to make these systems highly reliable and secure. However, large-scale network failures are on the rise, especially on the Internet. One of the main reasons is that existing approaches for detecting and responding to faults (or coordinated attacks) relies heavily on human intelligence. In addition to being very expensive, manual approaches provide poor responses and moreover, do not scale well. Dr. Sekar’s research is aimed at developing techniques for automating the detection, diagnosis and response to faults or attacks on large-scale networks.

Dr. Sekar is also interested in techniques that can prevent problems from occurring in the first place by employing a combination of high-level languages and advanced software development and quality assurance methodologies and tools. Of specific interest are declarative and object-oriented languages, as well as specification languages and domain-specific languages (DSLs). Such languages enable us to express high-level design abstractions naturally, thereby simplifying the task of initial coding as well as subsequent maintenance of software. His research is focused on the principles, techniques and tools for enabling wide-spread use of such languages, with particular emphasis on program analysis and optimization techniques aimed at efficient implementation of such languages. Complementing the languages, his is interested in advanced techniques for quasi-static debugging, which enlarge the class of software errors that can be caught at compile time or runtime. Finally, improving the quality of software through selective application of formal specification and automated verification techniques, especially in the context of concurrent systems is another of Dr. Sekar’s interests.

"A Specification-Based Approach for Building Survivable Systems," Sekar, R., Cai, Y., & Segal, M., National Information Systems Security Conference, October 1998.

"Improving Determinism in Logic Programs by Exploiting Necessary Conditions," Roychoudhury, A., Ramakrishnan, C.R., Ramakrishnan, I.V., & Sekar, R. IEEE/ACM International Conference on Computer Languages, May 1998.

"On the Power and Limitations of Strictness Analysis," Sekar, R., Mishra, P., & Ramakrishnan, I.V., Journal of the ACM (JACM), 44(3):505-525, May 1997.

EQUALS - "A Fast-Parallel Implementation of a Lazy Language," Kaser, O., Ramakrishnan, C.R., Ramakrishnan, I.V., & Sekar, R. Journal of Functional programming (JFP), 7(2):183-217, March 1997.

"Adaptive Pattern Matching," Sekar, R., Ramesh, R., & Ramakrishnan, I.V., SIAM Journal of Computing, December 1995.

"Fast Strictness Analysis Based on Demand Propagation," Sekar, R., & Ramakrishnan, I.V., ACM Transactions on Programming Languages and Systems (TOPLAS), November 1995.

"A Symbolic Constraint Solving Framework for Analysis of Logic Programs," Ramakrishnan, C.R., Ramakrishnan, I.V., & Sekar, R., ACM Conference on Partial Evaluation and Semantics Based Program Manipulation (PEPM), June 1995.

"Modelling Techniques for Evolving Distributed Applications," Sekar, R., Lin, Y,-J., and Ramakrishnan, C.R., Formal Description Techniques (FORTE), October 1994.

"The Touring Machine System: An Open Distributed Platform for Information Networking Application," B. Coan, G. Gopal, G.Herman, W. Leland, V. Mak, R. Sekar, A Weinrib and S. Wuu, 4^th Telecommunications Information Networking Architecture Workshop (TINA93), September 1993.

"Equational Logic-Programming: Beyond Strong Sequentiality," Sekar, R., & Ramakrishnan, I.V., IEEE Symposium on Logics in Computer Sciences (LICS), June, 1990. Invited from the conference to a special issue of Information and Computation, June 1993.

B.S. 1970, Mathematics & Physics, Hebrew University of Jerusalem, Israel

M.S. 1973, Computer Science, Weizmann Institute of Science, Rehovot, Israel

Ph.D. 1977, Computer Science, Tel-Aviv University, Tel-Aviv, Israel

Combinatorial algorithms, computational complexity, cryptography, formal languages, automata theory, relational data base theory, logic programming.

"Multi-valued Logic Programming Semantics: An Algebraic Approach," Slutzki, G., Mobasher, B., & Pigozzi, D. (1997). Theoretical Computer Science, 171:77-109.

"A Hierarchy of Deterministic Top-down Tree Transformations," Slutzki, G., & Vagvolgyi, S. (1996). Mathematical Systems Theory, 29:169-188.

"Computational Complexity of Term-Equivalence," Slutzki, G., Bergman, C., & Juedes, D.; to appear in the International Journal of Algebra and Computation.

"Using Sparsification for Parametric Minimum Spanning Tree Problems," Slutzki, G., Fernandez-Baca, D., & Eppstein, D. Special SWAT Issue of the Nordic Journal of Computing, 3(4):352-366, Winter 1996. Invited Paper.

B.A. 1962, Mathematics and Physics, Cornell College

Ph.D. 1969, Mathematics, Iowa State University

"Does APL Really Need Run-time Parsing?" Strawn, G.O. (1976). Software Practice and Experience.

Computer Architecture, VLSI: Complexity Theory, Low Energy VLSI Design Synthesis.

"Efficient Parallel Algorithms for Optical Computing with the DFT Primitive'," with J. Reif, in {\it Applied Optics}, 36:29, pp. 7327-9340, Optical Society of America, October 1997.

"Entropic Limitations on Finite State Machine Switching'," Tyagi, A., IEEE Transactions on VLSI Systems, 5:4, pp. 456-464, December 1997.

"Branch Decoupled Architectures," Tyagi, A. Proceedings of Workshop on Interaction Between Compilers and Computer Architectures at IEEE High Performance Computer Architecture Symposium. A summary to appear in IEEE TC on Computer Architecture Newsletter, pp. 13-15, June 1997.

"Statistical Module Level Area and Delay Estimation," VLSI Design, 5:2, pp. 141-153, April 1997, Gordon & Breach Publishers.

"Configurable memory Queues/Computing Units Architecture," Tyagi, A., in Proceedings of Reconfigurable Architectures Workshop at International Parallel Processing Symposium, April 1997.

"Minimizing Interconnect Energy through Integrated Low-Power Placement and Combinational Logic Synthesis," with Tyagi, A., & Holt, G., in Proceedings of ACM International Symposium on Physical Design, ACM Press, April 1997.

"Low-Power FSM Design using Huffman-Style Encoding," Tyagi, A., Surthi, P., & Chao, L.F., in Proceedings of European Design and Test Conference, IEEE Computer Society Press, March 1997.

"Efficient Parallel Algorithms for Optical Computing with the DFT Primitive," Tyagi, A., & J. Reif. (1997). To appear in Applied Optics.

Integrated Area-Power Optimal State Assignment," Tyagi, A., Proceedings of the Synthesis and Simulation Meeting and International Interchange, SASIMI ’96, November 1996.

"Re-Encoding for Low Power State Assignment of FSMs," Tyagi, A., Veeramachanenim, V., and Rajgopal, S. Proceedings of 1995 ACM International Symposium on Low Power Design, April 1995.

"A Reduced Area Scheme for Carry-Select Adders," IEEE Transactions on Computers, October 1993.

"VLSI Design Parsing," Tyagi, A., Proceedings of the IEEE International Conference on Computer-Aided Design, Santa Clara, November 1992.

"Energy Consumption in Multilective and Boundary VLSI Computations," Tyagi, A., IEEE Journal of Solid State Circuits, September 1991.

"An Optical Delay-Line Memory Model with Efficient Algorithms," Tyagi, A., & Reif, J. Proceedings of the ADVANCED RESEARCH in VLSI: International Conference 1991, MIT Press, March 1991.

"Energy Time Trade-offs in VLSI Computations," Tyagi, A., Proceedings of the Ninth Conference on Foundations of Software Technology & Theoretical Computer Science, Lecture Notes in Computer Science 405, Springer-Verlag, December 1989.

"Energy Complexity and Delay Comparison of Dynamic and Static PLA Design Styles,'' Tyagi, A., ADVANCED RESEARCH IN VLSI Proceedings of the 1987 Stanford Conference, MIT Press, March 1987.

B.S. 1977, Mathematics & Computer Science, The University of Hong Kong

M.S. 1982, Mathematics, The University of Sydney, NSW, Australia

Ph.D. 1987, Computer Science, The University of Sydney, NSW, Australia

Distributed Computing Environment (DCE), Distributed Operating Systems, Communication Protocols, Object-Oriented Systems and Databases, Common Object Request Broker Architecture (CORBA), Hypermedia Systems, Multimedia Information Systems, Intelligent Software Agents, Intrusion Detection.

Dr. Wong’s research interests include design and implementation issues in operating systems, distributed systems and multimedia communications. Current activities center around hypermedia, distributed multi-media database systems, and intelligent software agents.

In the area of communications network, several projects are under way, including research on coordinated multimedia communications, distributed computing environment (DCE), and Common Object Request Broker Architecture (CORBA).

The current research project is funded by Engineering Animation, Inc. on distributed database support for image visualization. In order to make a virtual reality application an effective tool, particular attention must be paid to support efficient and effective access to information. Our goal is to advance the level of support beyond the current state of technology. This is to include the perception of the environment and the support of the distributed processing.

"A Framework for a World Wide Web Based Data Mining System," Journal of Network and Computer Applications, to appear.

"A Multimedia Presentation Toolkit for the World Wide Web" Wong,J., Rao, S., & Ramaiah, N., Software: Practice and Experience, 27(4):425-446. April 1997.

"Remote Access to Multimedia Databases: An object-Oriented Approach" Wong, J., & Parthasarathy, D., Software: Practice & Experience, 26(6):677-704, June 1996.

"Design and Implementation of Heterogeneous Distributed Multimedia System using Mosaic GSQL," Wong, J., Magavi, S., & Bodla, P., Software: Practice & Experience, 25(11):1223-1242, November 1995.

"Design and Implementation of National Engineering Education Delivery System (NEEDS)," Wong,J., Schmitz, D., & Nelson, R. Software: Practice & Experience, 24(11):1051-1076, November 1994.

"Remote Database Access in Distributed Computing Environment," Wong, J., Marshall, W., & Goodman, R. Software: Practice & Experience, 24(4):421-434, April 1994.

"Transaction Management in an Object-Oriented Database System," Wong, J., & Shah, P. The Journal of Systems and Software, 24(2):115-124, February 1994.

"Transaction Management In Design Databases," Wong, J., & Kumar, M. The Journal of Systems and Software, 22(1):3-15, July 1993.

"Detecting Unsafe Error Recovery Schedules," Wong, J., & Lutz, R. IEEE Transactions on Software Engineering, August 1992, pp. 749-760.

"An Efficient Process Migration Algorithm in Distributed Systems," Wong, J., & Suen, T. IEEE Transactions on Parallel and Distributed Systems, July 1992, pp. 488-499.