Iowa State University

Iowa State UniversityIowa State University

College of Liberal Arts and Sciences

Department of Computer Science


With strong research programs in most computer science related subject areas, the Department of Computer Science at Iowa State University fosters an environment where faculty and graduate students routinely collaborate on research projects that cut across the many areas. The department also nurtures interdisciplinary work with research units and professional colleagues both within and outside the university - to advance the state of the art in the theoretical foundations as well as applications of computer science, while also contributing to advances in other disciplines (e.g. biological sciences, engineering). Computer Science faculty have received numerous research grants from the National Science Foundation, National Institutes of Health, Department of Defense, other federal and state funding agencies, as well as several industrial organizations. The department has recently cultivated one Presidential Young Investigator and five Career Award recipients. Some of the faculty members serve as Editor-in-Chief or a member on Editorial Boards of leading journals. Many regularly chair or serve on the Program Committees of top national and international research conferences. Dynamic faculty, state-of-the-art research laboratories, a well-funded research program, opportunities provided by the Center for Computational Intelligence, Learning, and Discovery; Center for Bioinformatics and Biological Statistics; Department of Energy Ames Laboratory; and Virtual Reality Applications Center provide a stimulating academic environment for leading-edge research in several areas. This document summarizes the current research interests of our faculty. Additional information can be found on our research page.

PAVAN ADURI, Assistant Professor of Computer Science

Ph.D. 2001, Computer Science, University at Buffalo, Buffalo

Major Interests:

Computational Complexity: Average-case complexity, Connections between average-case complexity and worst-case complexity, Properties of complete languages.

Current Research:

A major goal of Dr. Aduri's research is to understand the structure and complexity of the class NP. Dr. Aduri's current research is focused on the following themes:

  • Relations between average-case complexity and worst-case complexity: Some problems such as Permanent have the fascinating property that if they are easy on average, then they are easy in worst-case. Thus, the worst-case hardness of Permanent is the same as its average-case hardness. Can we show similar results for problems in NP, say Satisfiability or Hamiltonian Cycle?
  • Properties of NP-complete sets: What makes a set complete? Can we identify the properties responsible for completeness? How hard/easy are complete sets? How much information/redundancy is their in complete sets?

Representative Publications:

Hitchcock, J. and Pavan, A. (2006). Comparing reductions to complete sets. 33rd International Colloquium on Automata, Languages and Programming, LNCS 4051:465-476.

Glasser, C., Pavan, A., Selman, A. and Zhang, L. (2006). Redundancy in complete sets. 23rd International Symposium on Theoretical Aspects of Computer Science, LNCS 3884:444-454.

Glasser, C., Pavan, A., Selman, A.,and Sengupta, S. (2007). Properties of NP-complete sets. SIAM Journal on Computing, In press.

Hitchcock, J., Pavan, A., Vinodchandran, N. V. (2004). Partial bi-immunity and NP-completeness. Proceedings of the 19th IEEE Conference on Computational Complexity, 198-203.

 


SAMIK BASU, Assistant Professor of Computer Science

Ph.D. 2003, Computer Science, State University of New York at Stony Brook

Major Interests:

Formal methods, specification and verification of systems, model checking.

Current Research:

The main thrust of Dr. Basu's research is to develop techniques for the verification of infinite-state systems (protocols, embedded systems, source-code) and to ensure the safety and reliability of software systems. Two major activities of his research include (a) developing efficient techniques to detect system flaws and (b) enhancing debugging capabilities by building effective justification of the cause of these flaws. Dr. Basu is also involved in projects on supervisory control, protocol conversion, open system verification and service composition where the primary objective is to generate controllers or converters or choreographers that can force the systems to behave in a desirable fashion. In addition, Dr. Basu actively participates in projects involving the application of formal techniques for developing intrusion detection and response systems.

Representative Publications:

Basu, S and Ramakrishnan, C.R. (2006). Compositional Analysis for Verification of Parameterized Systems. Journal of Theoretical Computer Science (TCS).

Yang, P., Basu, S. and Ramakrishnan, C.R.. Parameterized Verification of Pi-Calculus Systems. International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS).

Basu, S., Roop, P.S.and Sinha, R. (2006) Local Module Checking for CTL specifications. Formal Foundations of Embedded Software and Component-Based Software Architectures (FESCA). Best Paper Award.

Basu, S. and Kumar, R. (2006) Quotient-based Control Synthesis for Non-Deterministic Plants with Mu-Calculus Specifications.IEEE Conference on Decision and Control (CDC).

Kumar, R., Zhou, C., and Basu, S. (2006) Finite Bisimulation ofReactive Untimed Infinite State Systems Modeled as Automata with Variables. American Control Conference (ACC).

Pathak, J., Basu, S., Lutz, R. and Honavar, V.(2006). Selecting and Composing Web Services through Iterative Reformulation of Functional Specifications . Proceedings of the IEEE International Conference on Tools with Artificial Intelligence (ICTAI 2006), Washington, DC, IEEE. (Best Paper Award).

Pathak, J., Basu, S., and Honavar, V.Modeling Web Services by Iterative Reformulation of Functional and Non-Functional Requirements.4th International Conference on Service Oriented Computing (ICSOC 2006).

Pathak, J., Basu, S., Lutz, R. and Honavar, V. (2006). Parallel Web Service Composition in MoSCOE: A Choreography-based Approach.4th IEEE European Conference on Web Services (ECOWS 2006).

Stakhanova, N., Basu, S., Lutz, R. and Wong, J. (2006).Automated Caching of Behavioral Patterns for Efficient Run-time Monitoring. IEEE International Symposium on Dependable, Autonomic and Secure Computing (DASC 2006).



YING CAI, Assistant Professor of Computer Science

Ph.D. 2002, Computer Science, University of Central Florida

Major Interests:

Mobile Computing and Networking, Peer-to-Peer Systems, Multimedia Communications.

Current Research:

Dr. Cai is investigating a new type of computing called geotasking.A geotasking system is formed by a set of position-aware mobile hosts that communicate with each other through wireless networks. Geotasking treats the geographic environment as its storage disk; as mobile hosts move, they load and execute the programs implanted in their surroundings.The research aims at addressing various aspects of geotasking, including execution triggers, dynamic binding, and concurrent execution of geotasks with memory mapping.In addition to geotasking, Dr. Cai is developing a new-generation peer-to-peer framework for large-scale and cost-effective distributions of video data, either prerecorded or live, over the Internet. The research in this area is to investigate a suite of innovative solutions for topology-aware video storage, streaming and downloading, and service scheduling.

Representative Publications:

Cai, Y. and Zhou, J. (2007). An Overlay Subscription Network for Live Internet TV Broadcast. IEEE Transactions on Knowledge and Data Engineering. In press.

Cai, Y., Natarajan, A., and Wong, J. (2007). On Scheduling of Peer-to-Peer Video Services. IEEE Journal on Selected Areas in Communications, Peer-to-Peer Communications and Applications In press.

Cai, Y., Chen, Z., and Tavanapong, W. (2007). Caching Collaboration and Cache Allocation in Peer-to-Peer Video Systems . Journal of Multimedia Tools and Applications. In press.

Cai, Y., Hua, K. A., Cao, G., and Xu, T. (2006).Real-Time Processing of Range-Monitoring Queries in Heterogeneous Mobile Databases.IEEE Transactions on Mobile Computing. Vol. 5. No. 7. pp. 931-942, 2006.

Cai, Y., and Hua, K. A.Sharing Multicast Videos Using Patching Streams. Journal of Multimedia Tools and Applications. Vol.21, No.2, pp. 125-146, 2003.

 


CARL K. CHANG, Professor and Chair of Computer Science

Ph.D. 1982, Computer Science, Northwestern University, Evanston, Illinois

Major Interests:

Requirements Engineering, Software Architecture, Services Computing, Collaboration Technology, Project Management.

Current Research:

Dr. Chang's research in software engineering includes two major activities: software architecture based requirements engineering and project management with genetic algorithms. His research in net-centric computing currently focuses on rule-mitigated collaboration technology to support formal electronic meetings. His interests in services computing include dynamic composition and QoS issues of web services, requirements analysis and decomposition of service-oriented architecture with aspects, and service pricing strategies.

Representative Publications:

Xia, J., Chang, C. K., Wise, J. and Ge, Y. (2006). An Empirical Performance Study on PSIM. The Computer Journal, Oxford University Press. Vol. 49. No. 5. pp. 509-526.

Zhang, J., Chang, C., Hung, P., and Zhang, L.-J. Phased Transformation toward Services-Oriented Architecture. Accepted by IEEE Transactions on Systems, Man, and Cybernetics, Part A.

Kim, T. and Chang, C. (2006) An Aspect-Oriented Approach to Resource Composition in Petri net-based Software Architectural Models. 30th Annual International Computer Software and Applications Conference (COMPSAC 2006), Chicago. pp. 87-94.

Xia, J., Ge, Y., and Chang, C. (2005). An Empirical Performance Study for Validating a Performance Analysis Approach: PSIM. Proc. of 29th Annual International Computer Software and Applications Conference (COMPSAC 2005), July 26-28, 2005, Edinburgh, Scotland, UK, pp. 307-312. Best Paper.

Kim, T. and Chang, C. Service-Oriented Design with Aspects (SODA). (2005). IEEE Int'l Conf. Services Computing (SCC 2005), Orlando, FL. pp. 319-324.

Cleland-Huang, J., Chang, C.and Christensen, M (2003). Event-Based Traceability for Managing Evolutionary Change. IEEE Transactions in Software Engineering. Vol. 29. No. 9. pp. 796 - 810.

Cleland-Huang, J., Chang, C. K. and Wise, J. (2003). Automating performance-related impact analysis through event based traceability. Requirements Engineering Journal, Springer-Verlag. Vol. 8. No. 3. pp. 171 - 182.

Cai, L., Chang, C., and Cleland-Huang, J. Supporting Agent-based Distributed Software Development through Modeling and Simulation. Prof. of 2003 IEEE Workshop on Future Trends of Distributed Computing Systems, San Juan, Puerto Rico. pp. 56-62, 2003.

Cleland-Huang, J., Chang, C.K., Sethi, G., Javvaji, K., Hu, H., andXia, J. (2002). Automating speculative queries through event-based requirements traceability. Proceedings IEEE Joint Int'l Conf. Requirements Engineering (RE'02), Essen, Germany. pp. 289-296. Best Research Paper.

Chang, C., Cleland-Huang, J., Hua, S. and Combelles, A. (2001). On Function-Class Decomposition. IEEE Computer, Dec. 2001, pp. 87-93.

Chang, C., Zhang, T. and Christensen, M. (2001). Genetic Algorithms for Project Management. Annals of Software Engineering, Kluwer Academic Publishers, 11:107-139, Nov. 2001.

Chang, C. and Shih, C-C. (1999). A Circular Skip-Cluster Scheme to Support Video-on-Demand Services. ACM Multimedia Systems, Springer-Verlag, 7(2):107-118.

 


SOMA CHAUDHURI, Associate Professor of Computer Science

Ph.D. 1990, Computer Science & Engineering, University of Washington

Research Interests:

Theory of distributed computing: distributed algorithms in shared memory and message passing models of computation; distributed data structures; algorithms, lower bounds and impossibility results for asynchronous and partially synchronous systems; fault-tolerance. Mobile Computing: theoretical models, lower bounds and algorithms for computing in ad hoc networks. Security Protocols: Distributed Consensus-based algorithms in security. Software Obfuscation and Watermarking. Secret Sharing, Security Policies.

Current Research:

Dr. Chaudhuri's research in the theory of distributed computing systems includes algorithm design and analysis, and lower bounds and impossibility results for a variety of problems, including consensus, set consensus and resource allocation. She is particularly interested in studying the complexities that arise due to the presence of uncertainty caused by asynchrony and failures in distributed systems. Her research focused on understanding the differences in computational power between a variety of timing models, ranging from synchronous to asynchronous models of distributed computation. Dr. Chaudhuri has also done research on consistency conditions for distributed shared memory. The problem here is to define consistency conditions that are weak enough that they are easy to support by the underlying architecture but still strong enough to allow correctness of concurrent programs. Dr. Chaudhuri is also interested in algorithms and lower bounds for distributed data structures.

Dr. Chaudhuri has interests in the area of mobile, ad hoc and wireless networks. Such networks are unpredictable due to frequent link failures when nodes drift apart and link formations when nodes drift closer to each other. Existing distributed algorithms that rely on static communication links cannot run in such networks. Instead, efficient algorithms would have to be designed that adjust to the mobility of the network.

Another of Dr Chaudhuri's research interests lies in Security in Distributed Systems. Software protection ensures the digital rights of the software vendors. Specific technologies to support software protection are software obfuscation, anti-tamper, and watermarking. Obfuscation makes it hard for a hacker to learn anything more about the program than he needs to be able to use the program; specifically it makes it hard to reverse-engineer the high level program from the machine level code and observation of its black-box behavior. There has been theoretical work that has formalized the notion of obfuscation and shown that there exist functions that cannot be obfuscated. Dr. Chaudhuri  is interested in developing new definitions for obfuscation that are more useful in practice, and come up with existence and impossibility results. 

Some distributed problems dealing with asynchronous communication arise within the context of large scale embedded system designs. Those issues are also being explored.

Representative Publications:

Ge, J., Chaudhuri, S. & Tyagi, A.(2005). "Control-Flow Based Obfuscation." Proceedings of the Fifth ACM Workshop on Digital Rights Management.

Chaudhuri, S.,Herlihy, M., Lynch, N. & Tuttle, M. (2000). "Tight Bounds for k-Set Agreement."  Journal of the ACM, 47 (5): 912--943, November 2000.

Chaudhuri, S.,Kosa, M. & Welch, J. (2000). "One-Write Algorithms for Multi-Valued Regular and Atomic Registers,"  Acta Informatica, 37 (3): 61-192.

Chaudhuri, S.,Herlihy, M. & Tuttle, M. (1999) "Wait-Free Implementations in Message Passing Systems."  Theoretical Computer Science, 220 (1): 211-245, June 1999.

Chaudhuri, S., Attiya, H., Friedman, R. &Welch, W. (1998). "Shared Memory Consistency Conditions for Non-Sequential Execution: Definitions and Programming Strategies,"  SIAM Journal on Computing, 27 (1): 65-89, February 1998.

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

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

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

Chaudhuri, S., Gawlick, R. & Lynch, N. (1993). "Designing Algorithms for Distributed Systems with Partially Synchronized Clocks," Proceedings of the Twelfth Annual ACM Symposium on Principles of Distributed Computing, August 1993.

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

 


HUI-HSIEN CHOU, Associate Professor of Computer Science & Genetics, Development & Cell Biology

Ph.D., 1996, Computer Science, University of Maryland at College Park

Major Interests:

Bioinformatics and computational biology; cellular automata and artificial life; and programming methods and compiling.

Current Research:

Dr. Chou's research centers around two complementary areas: computational biology and artificial life. In computational biology he studies how to best analyze the vast amount of biological data generated by high-throughput genomics and transcriptomics studies. These studies allow us to gather explosively more biological data, but only computers can efficiently analyze the resulted huge quantity of data. Previously Dr. Chou has designed DNA sequence quality assurance and microarray design software. He is currently developing an integrated approach of biological data analysis that combines sequence, structure, microarray and pathway data to better assist biologists to gain novel biological insights. He has also created an automatic Perl programming tool, which can automatically generates working Perl programs for biologists who may not know how to program in Perl directly.

Dr. Chou's work on artificial life has focused on the use of cellular automata to model self-replication. Dr. Chou has developed the Trend cellular automata programming language for programming cellular automata models.

Representative Publications:

Scott Emrich, Li Li, Tsui-Jung Wen, Marna Yandeau-Nelson, Yan Fu, Ling Guo, Hui-Hsien Chou, Srinivas Aluru, Daniel Ashlock, and Patrick Schnable. Nearly identical paralogs (NIPs): implications for maize (Zea mays L.) genome evolution. Genetics, 175(1):429?39, Jan. 2007

Maher, P., Chou, H-H., Hahn, E., Wen, T-J. and Schnable, P. (2006). GRAMA: Genetic mapping analysis of temperature gradient capillary electrophoresis (TGCE) Data. Theoretical and Applied Genetics, 113(1):156-162, June 2006.

Chou, H-H. (2005). Computational Design of Whole Genome Microarrays. In Srinivas Aluru, editor, Handbook of Computational Molecular Biology. ISBN 1584884061. CRC Press, Boca Raton, FL, 2005.

Chou, H-H. (2005). Vect: an automatic visual Perl programming tool for nonprogrammers. BioTechniques, 38:615-621, April 2005.

Li, S. and Chou, H-H. (2005). UBViz: Explore Biochemical Pathways in 3-D Space. BioTechniques, 38:540-542, April 2005.

Chou, H-H., Hsia, A-P., Mooney, D. and Schnable. P., (2004).Picky: Oligo Microarray Design for Large Genomes. Bioinformatics, 20:2893-2902, Nov. 2004.

Li, S. and Chou, H-H. (2004).Lucy2: an interactive DNA sequence quality trimming and vector removal tool. Bioinformatics, 20:2865-2866, Nov. 2004.

Huang, X., Ye, L.,Chou, H-H., Yang, I-H. and Chao, K-M. (2004). Efficient Combination of Multiple Word Models for Improved Sequence Comparison. Bioinformatics, 20:2529-2533, Nov. 2004.

Chou, H-H., Huang, W., and Reggia, J. (2002). The Trend Cellular Automata Programming Environment. Simulation, 78:59−75, Feb. 2002.

Chou, H-H., and Holmes, M. (2001). DNA Sequence Quality Trimming and Vector Removal. Bioinformatics, 17:1093−1104, Dec. 2001.

Myers, E., Sutton, G., Delcher, A., Dew, I., Fasulo, D., Flanigan, M., Kravitz, S., Mobarry, C.,Reinert, K., Remington, K., Anson, E., Bolanos, R.,Chou, H-H., Jordan, C., Halpern, A., Lonardi,S., Beasley, E., Brandon, R., Chen, L., Dunn, P., Lai, Z., Liang, Y., Nusskern, D., Zhan, M.,Zhang, Q., Zheng, X., Rubin, G., Adams, M., and Venter, J. C. (2000). A Whole-Genome Assembly of Drosophila. Science, 287:2196−2204, March 24, 2000.

 


OLIVER EULENSTEIN, Associate Professor of Computer Science

Ph.D. 1998, Computer Science, University at Bonn, Germany

Major Interests:

Algorithms, Computational Complexity, Bioinformatics and Computational Biology.

Current Research:

Dr. Eulenstein's research area is in computational biology, that is, the development of computational methods and algorithms for molecular biology. In particular, his research is aimed at supporting evolutionary biologists with powerful computational tools in their efforts to construct the Tree of Life. This tree connects all life on earth through a complex tree-like structure of evolutionary relationships. Connecting the estimated 4 trillion species (from which only about 1.75 million are recorded), the Tree of Life is of enormous size. However, a description of this tree will provide biologists with a predictive power similar to the one that chemists have from the Periodic Table of Elements. Thus, knowing the Tree of Life, or large parts of it, would result in an enormous benefit to science and society. Unfortunately, only very small parts of the Tree of Life could be constructed so far. Evolutionary biologists are faced with the problem assembling the Tree of Life from the phylogenetic information of over 1.75 million recorded species. In analogy, this task is similar to the task of assembling a complex alien starship from its pieces without having any documentation. However, advances in the development of powerful algorithms will allow evolutionary biologists to assemble large parts of the Tree of Life within the next two decades. As part of an interdisciplinary research team, it is Dr. Eulenstein's research mission to meld the power of algorithm theory with the biologists' expert-knowledge into applications that will allow constructing large parts of the Tree of Life.

Representative Publications:

Bansal, M., Burleigh, G., Eulenstein, O., and Wehe, A.."Heuristics for the Gene-duplication Problem: An Omega(n)Speed-up for the Local Search" (accepted), RECOMB 07

Chen, D.,Burleigh, J.G., Eulenstein, O.and Fernández-Baca, D. (2006). Improved heurisitcs for minimum-flip supertree construction; evolutionary bioinfor-matics. Evolutionary Bioinformatics, (accepted).

Chen, D., Eulenstein, O., Fernández-Baca, D., and Sanderson M. J. (2006). Minimum-flip supertrees. IEEE Transactions on Computational Biology and Bioinformatics, 3(2):165-173.

Wilkinson, M., Cotton, J. A., Creevey, C., Eulenstein, O., Harris, S. R., Lapointe, F., Levasseur,C., Mcinerney, J. O., Pisani, D. and Thorley J. L. (2005). The shape of supertrees to come: Tree shape related properties of fourteen supertree methods. Systematic Biology, 54(3):419-431.

Yan, C., Burleigh, J. G., and Eulenstein O. (2005). Identifying optimal incomplete phylogenetic data sets from sequence databases. Molecular Phylogenetics and Evolution, 35:528-535.

Chen, D., Eulenstein, O. and Fernández-Baca, D. (2004). Rainbow: A tool-box for phylogenetic supertree construction and analysis. Bioinformatics,20(16):2872-2873.

Eulenstein, O.,Chen, D., Burleigh, J. G., Fernández-Baca, D. and Sanderson M. J. (2004). Performance of flip-supertree construction. Systematic Biology, 53(2):1-10.

Eulenstein, O. and Vingron, M. (1998). On the equivalence of two tree mapping measures. Discrete Applied Mathematics, 88:103-128.

Eulenstein, O., Mirkin, B.and Vingron, M. (1998). Duplication based measures of difference between gene- and species trees. Journal of Computational Biology, 5:135-148.

Chang, W. and Eulenstein, O. (2006). Reconciling trees with apparent polytomies; computing and combinatorics. In D. Z. Chen and D. T. Lee, editors, 2th Annual International Conference. Lecture Notes in Computer Science, number 4112 in LNCS, pages 235-244. Springer.

 


DAVID Fernández-Baca, Professor of Computer Science

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

Major Interests:

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

Current Research:

Dr. Fernández-Baca's two main areas of research are sensitivity analysis of optimization problems and the construction of evolutionary (phylogenetic) trees.The goal of the first of these fields is to determine how the optimum solutions to optimization problems are affected by changes in the input data. Dr. Fernández-Baca's work has led to sensitivity analysis algorithms for specific problems, such as computing minimum spanning trees, as well as general-purpose techniques that apply to a variety of problems.He also studies how statistical models of biological sequence comparison are affected by changes in assumptions about evolutionary distance.

Dr. Fernández-Baca's other area of research aims to develop efficient algorithms for building reliable evolutionary trees for sets of species.He has studied issues surrounding the method of parsimony, which seeks a tree that explains evolution using the fewest number of evolutionary changes. He is also interested in two related problems: reconciling conflicting phylogenetic information -the "supertree" problem - and partitioning phylogenetic information into highly compatible subsets - that is, into clusters that provide similar evolutionary "signal." Additionally, Dr. Fernández-Baca studies problems at the boundary between phylogenetics and sensitivity analysis, such the effect of evolutionary distance on tree construction.

Representative Publications:

D. Fernández-Baca and B. Venkatachalam. Sensitivity Analysis in Combinatorial Optimization. To appear in Handbook of Approximation Algorithms and Metaheuristics (T. Gonzalez, ed.), Chapman and Hall/CRC Press Computer and Information Science Series.

D. Chen, O. Eulenstein, D. Fernández-Baca, and M.J. Sanderson. Minimum flip supertrees: Complexity and algorithms. IEEE Trans. Bioinformatics and Computational Biology, April-June 2006 (Vol. 3, No. 2)   pp. 165-173.

D. Fernández-Baca and B. Venkatachalam. Parametric analysis for ungapped Markov models of evolution. In Proc. Combinatorial Pattern Matching, Springer LNCS, Vol. 3537, pp. 394-405, 2005.

D. Fernández-Baca and B. Venkatachalam. Parametric sequence alignment. In Handbook of Computational Molecular Biology (S. Aluru, ed.), Chapman and Hall/CRC Press Computer and Information Science Series, 2005.

F. Sun, D. Fernández-Baca, and W. Yu. Inverse parametric sequence alignment. Journal of Algorithms, 53(1):36--54 (2004).

D. Chen, O. Eulenstein, and D. Fernández-Baca. Rainbow: A toolbox for phylogenetic supertree construction and analysis. Bioinformatics 20(16):2872-2873 (2004).

D. Fernández-Baca, T. Seppäläinen, and G. Slutzki. Parametric multiple sequence alignment and phylogeny construction. Journal of Discrete Algorithms, 2(2):271-287 (2004), special issue on Combinatorial Pattern Matching, edited by R. Giancarlo and D. Sankoff.

Eulenstein, O., Chen, D., Burleigh J.G., Fernández-Baca, D.and Sanderson. M.J. (2004). Performance of flip supertrees with a heuristic algorithm. Systematic Biology, 53(2):299-308, 2004.

Fernández-Baca, D.and Lagergren, J. (2003). A polynomial-time algorithm for near-perfect phylogeny. SIAM J. Computing, 32(5):1115-1127.

Chen D., Diao L., Eulenstein O.,Fernández-Baca D. and Sanderson M.J. (2003). Flipping: A supertree construction method. In Bioconsensus, M. Janowitz et al. (eds), DIMACS Series in Discrete Mathematics and Theoretical Computer Science, vol. 61, pp. 135-160, American Mathematical Society.

Fernández-Baca, D. (2003). Decomposable multiparameter matroidal knapsack problems. Theoretical Computer Science, 297:183-198.

Fernández-Baca, D., Seppäläinen, T. and Slutzki, G. (2002). Bounds for parametric sequence comparison. Discrete Applied Mathematics, 118:181-198.

Fernández-Baca, D. (2001). The perfect phylogeny problem. In Steiner Trees in Industry, X. Cheng and D.-Z. Du (eds.), pp. 203-234, Kluwer.

Fernández-Baca, D. (2001). On nonlinear parametric search. Algorithmica, 30:1-11.

 


SHASHI K. GADIA, Associate Professor of Computer Science

Ph.D. 1977, Mathematics, University of Illinois

Major Interests:

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

Current Research:

Dr. Gadia's major research interests center around storage and retrieval of parametric data, data with underlying dimensions such as space, time, and beliefs and XML (extendible markup language). Dr. Gadia's research on parametric data has led to the development of ParaSQL, a natural query language for users of parametric data. Hisresearch on XML has led to the development of a novel storage technology CanStoreX.

Representative Publications:

Noh, S-Y. and Gadia, S. (2006). A Comparison of Two Approaches to Utilizing XML in Parametric Databases for Temporal Data. Information and Software Technology, Vol 48, pp807-819.

Noh, S-Y. and Gadia, S. (2005) An XML-based Framework for Temporal Database Implementation. Proc. Twelfth International Symposium on Temporal Representation and Reasoning.

Bertino, E., Cheng, T., Gadia, S. and Guerrini, G. (2001). A linguistic framework for multidimensional data, Proceedings Eighth International Symposium on Temporal Representation and Reasoning.

Merlo, I., Bertino, E., Ferrari, E., Gadia, S. and Guerrini, G. (2000). Querying multiple temporal granularity data. Proceedings Seventh International Workshop on Temporal Representation and Reasoning.

Gadia, S. and Nair, S. (1998). Algebraic identities and query optimization in the parametric model for relational temporal databases. IEEE Transactions on Knowledge and Data Engineering. Vol 10(5), pp 793-807.

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

Gadia, S., Nair, S., & Poon, Y. (1993) "Incomplete Information in Relational Temporal Databases,". Proceedings of the 18th International Conference on Very Large Databases, pp. 395-406.

Gadia, S. and Bhargava, G.The concept of an error in a database: an application of temporal databases. Appeared in Proceedings of INSDOC COMAD90 International Conference on Management of Data, December 1990.

Gadia, S. and Yeung, C-S. (1998). A Generalized Model for a Relational Temporal Database. ACM SIGMOD Conference on Management of Data, pp. 251-259.

Gadia, S. (1998). A Homogeneous Relational Model and Query Languages for Temporal Databases. ACM Transactions on Database Systems, 14:418-448.

 


VASANT HONAVAR, Professor of Computer Science

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

Major Interests:

Artificial Intelligence, Machine Learning, Neural Computation, Probabilistic models, Bioinformatics, Computational Molecular and Systems Biology, Computational Neuroscience, Data Mining, Computational Learning Theory, Information Integration, Ontologies, Knowledge Representation, and Inference, Semantic Web, Service-Oriented Computing, e-Science cyberinfrastructure, Biomedical Informatics, Engineering informatics, Materials Informatics, Security Informatics, Environmental Informatics, Social Informatics

Current Research:

Dr. Honavar's recent research focuses on:

  • Scalable algorithms for learning predictive models (e.g., classifiers) from very large distributed data and multi-relational data
  • Logical and probabilistic approaches to flexible integration of semantically disparate, autonomous information sources, with emphasis on efficient algorithms for answering statistical queries in such settings
  • Learning predictive models from partially specified data
  • Learning predictive models from richly structured data e.g., sequences, directed or undirected, weighted or unweighted, labeled or unlabeled graphs and multi-graphs, and hypergraphs
  • Modular ontology languages including modular description logics (DL), modular RDF, distributed reasoning algorithms, and privacy-preserving inference strategies for selective knowledge sharing in open environments e.g., semantic web
  • Interactive assembly of complex services from autonomous components services from functional and non-functional requirements
  • Machine learning applications in bioinformatics and computational and systems biology including gene and protein annotation, prediction of functionally important sites (e.g., protein-protein, protein-DNA, and protein-RNA interfaces, phosphorylation and glycosylation sites), and construction, analysis, and simulation of biomolecular networks and pathways

Dr. Honavar's research is supported in part by grants from the National Science Foundation, the National Institutes of Health, the United States Department of Agriculture, the United States Department of Energy, and the ISU Center for Computational Intelligence, Learning, and Discovery. Additional information about Dr. Honavar's research can be found at www.cs.iastate.edu/~honavar/aigroup.html

Selected Recent Publications:

Bao, J., Voutsadakis, G., Slutzki, G., and Honavar, V. On the Decidability of Role Mappings between Modular Ontologies. In: Proceedings of the 23nd Conference on Artificial Intelligence (AAAI-2008), Chicago, USA, AAAI, In press.

El-Manzalawy, Y., Dobbs, D., and Honavar, V. (2008) Predicting linear B-cell epitopes using string kernels. Journal of Molecular Recognition, DOI:10.1002/jmr.893

Hecker, L., Alcon, T., Honavar, V., and Greenlee, H. Analysis and Interpretation of Large-Scale Gene Expression Data Sets Using a Seed Network. Journal of Bioinformatics and Biology Insights. Vol. 2. pp. 91-102, 2008.

Honavar, V. and Caragea, D. (2008). Towards a Semantics-Enabled Infrastructure for Knowledge Acquisition from Distributed Data. In: Next Generation Data Mining. Kargupta, H. et al. (ed). CRC Press. In press.

Pathak, J., Basu, S., and Honavar, V. (2008). Composing Web Services through Automatic Reformulation of Service Specifications. IEEE International Conference on Services Computing, IEEE. Vol. In press.

Andorf, C., Dobbs, D. and Honavar, V. (2007). Exploring Inconsistencies in Genome Wide Protein Function Annotations: A Machine Learning Approach. BMC Bioinformatics 8:284 doi:10.1186/1471-2105-8-284

Bao, J., Slutzki, G., and Honavar, V. (2007). A Semantic Importing Approach to Knowledge Reuse from Multiple Ontologies.. In: Proceedings of the 22nd Conference on Artificial Intelligence (AAAI-2007). Vancouver, Canada. pp. 1304-1309. AAAI Press.

Bao, J., Slutzki, G., and Honavar, V. (2007). Privacy-Preserving Reasoning on the Semantic Web. IEEE/WIC/ACM Conference on Web Intelligence. IEEE. pp. 791-797

Caragea, C., Sinapov, J., Silvescu, A., Dobbs, D. And Honavar, V. (2007). Glycosylation Site Prediction Using Ensembles of Support Vector Machine Classifiers. BMC Bioinformatics. doi:10.1186/1471-2105-8-438.

Yan, C., Dobbs, D., Jernigan, R., and Honavar, V. (2007). Characterization of Protein-Protein Interfaces. The Protein journal. doi:10.1007/s10930-007-9108-x

Kang, D-K., Silvescu, A. and Honavar, V. (2006) RNBL-MN: A Recursive Naive Bayes Learner for Sequence Classification. Proceedings of the Tenth Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD 2006). Lecture Notes in Computer Science., Berlin: Springer-Verlag. pp. 45-54, 2006.

Silvescu, A. and Honavar, V. (2006) Independence, Decomposability and functions which take values into an Abelian Group. Proceedings of the Ninth International Symposium on Artificial Intelligence and Mathematics, 2006.

Terribilini, M., Lee, J.H., Yan, C., Jernigan, R., Honavar, V., and Dobbs, D. (2006). Computational Prediction of Protein-RNA Interfaces. RNA Journal.. Vol. 12. No. 1450. pp. 1462, 2006.

Yan, C., Terribilini, M.,Wu, F., Jernigan, R.L., Dobbs, D. and Honavar, V. (2006). Identifying amino acid residues involved in protein-DNA interactions from sequence. BMC Bioinformatics. Vol. 7. pp. 262-, 2006.

Zhang, J., Silvescu, A., Kang, D-K., and Honavar, V. (2006). Learning Compact and Accurate Naive Bayes Classifiers from Attribute Value Taxonomies and Partially Specified Data. Knowledge and Information Systems. Vol. 9. No. 2. pp. 157-179, 2006.

Caragea, D., Zhang, J., Bao, J., Pathak, J., and Honavar, V. (2005). Algorithms and Software for Collaborative Discovery from Autonomous, Semantically Heterogeneous, Distributed, Information Sources. Invited paper. In: Proceedings of the Conference on Algorithmic Learning Theory. Lecture Notes in Computer Science. Vol. 3734. Berlin: Springer-Verlag. pp. 13-44.

Yakhnenko, O., Silvescu, A., and Honavar, V. (2005). Discriminatively Trained Markov Model for Sequence Classification. In: Proceedings of the IEEE Conference on Data Mining (ICDM 2005). IEEE Press. pp. 498-505.

R. Polikar, L. Udpa, S. Udpa, and V. Honavar (2004). An Incremental Learning Algorithm with Confidence Estimation for Automated Identification of NDE Signals. IEEE Transactions of Ultrasonics, Ferroelectrics, and Frequency Control. Vol. 51. pp. 990-1001, 2004.

Zhang, J. and Honavar, V. (2003). Learning Decision Tree Classifiers from Attribute-Value Taxonomies and Partially Specified Data. In: Proceedings of the International Conference on Machine Learning. Washington, DC. AAAI Press. pp. 880-887.

Parekh, R. and Honavar, V. (2001). Learning DFA from Simple Examples. Machine Learning. Vol. 44. pp. 9-35.

 


XIAOQIU HUANG, Associate Professor of Computer Science

Ph.D. 1990, Computer Science, Pennsylvania State University

Major Interests:

Bioinformatics and computational biology: design and applications of computational methods for understanding the structure and evolution of genomes.

Current Research:

The long term goal of Dr. Huang's research is to develop computational methods for finding functional elements in genomes. He has worked on two major problems: genome assembly and alignment.

Genome Assembly

Dr. Huang and collaborators at Genome Sequencing Center (GSC) of Washington University in St. Louis have developed a packaged named PCAP for reconstructing long genome sequences from short DNA sequences generated in whole-genome shotgun sequencing projects. The PCAP package has been used at GSC in a number of large-scale genome sequencing projects including the chimpanzee and chicken genome projects. Dr. Huang has also developed a sequence assembly program named CAP3.The CAP3 program has been used in thousands of academic labs for assembly of sequences from gene coding regions of the genome. PCAP and CAP3 are freely available for academic use at http://seq.cs.iastate.edu.

Genome assembly is a challenging computational problem. An input data set from a mammalian genome consists of up to 40 millions of sequences with a total size of 30 GB. A genome assembly program takes several days to produce a draft assembly from the input data set on hundreds of processors. Dr. Huang and collaborators continue to make accuracy and efficiency improvements to the PCAP package and to develop computational methods for sequence data from new genome sequencing technology.

Genome Alignment

Once the DNA sequence of a genome is determined, computational methods are used to find genes and regulatory elements in the genome. A very effective computational method for finding genes and regulatory elements in the genome is to compare the new genome sequence with existing genome sequences from other species, where similar regions between the new genome and existing genomes are located and aligned. The genome alignment method is based on the evolutionary law that genes and regulatory elements in the genomes of related species are much more conserved than the other regions of the genomes.

Dr. Huang and collaborators have designed a number of alignment algorithms and implemented the algorithms in computer programs available to biologists for analysis of DNA and protein sequences. A program named SIM computes a number of optimal local alignments between two sequences in linear space. The SIM program has been used in thousands of academic labs for analysis of protein sequences. A program named GAP3 is based on a dynamic programming algorithm specially designed to handle introns in genomic DNA sequences. Fast comparison programs based on a lookup table or a superword array (an efficient variation of a suffix array) have been developed by Dr. Huang and collaborators.

A package named AAT of alignment and comparison programs has been used for many years at The Institute for Genomic Research for finding genes in a genome. Many of the programs can be used at http://deepc2.psi.iastate.edu/aat/sas.html. Dr. Huang and collaborators continue to design better alignment models and algorithms for producing genome alignments.

See http://www.cs.iastate.edu/~xqhuang for details.

Representative Publications:

Huang, X., Yang, S.-P., Chinwalla, A., Hillier, L., Minx, P., Mardis, E. and Wilson, R.(2006). Application of a Superword Array in Genome Assembly. Nucleic Acids Research, 34:201-205.

Wang, J. and Huang, X.(2005). A Method for Finding Single-Nucleotide Polymorphisms with Allele Frequencies in Sequences of Deep Coverage. BMC Bioinformatics, 6:220.

Ye, L. and Huang, X.(2005). MAP2: Multiple Alignment of Syntenic Genomic Sequences. Nucleic Acids Research, 33:162-170.

Huang, X., Ye, L., Chou, H.-H., Yang, I-H. and Chao, K.-M.(2004). Efficient Combination of Multiple Word Models for Improved Sequence Comparison. Bioinformatics, 20:2529-2533.

Huang, X., Wang, J., Aluru, S., Yang, S.-P. and Hillier, L. (2003). PCAP: A Whole-Genome Assembly Program. Genome Research, 13:2164-2170.

Huang, X. and Chao, K.-M. (2003). A Generalized Global Alignment Algorithm. Bioinformatics, 19:228-233.

Huang, X, and Madan, A. (1999). CAP3: A DNA Sequence Assembly Program. Genome Research, 9:868-877.

Huang, X, Adams, M.D., Zhou, H., and Kerlavage, A.R. (1997). A Tool for Analyzing and Annotating Genomic Sequences. Genomics, 46:37-45.

Huang, X., and Zhang, J. (1996). Methods for Comparing a DNA Sequence with a Protein Sequence. Computer Applications in the Biosciences. 12:497-506.

Huang, X. and Miller, W. (1991) A Time-Efficient, Linear-Space Local Similarity Algorithm. Advances in Applied Mathematics, 12:337-357.

 


YAN-BIN JIA, Associate Professor of Computer Science

Ph.D. 1997, Robotics (and Computer Science), Carnegie Mellon University

Major Interests:

Robotics and artificial intelligence, geometric algorithms for curves and surfaces, tactile shape recognition and reconstruction, sensor implementation, localization and robot sensing, computational geometry and modeling, planning and control for robot dexterity, robot interfaces, optimization, nonlinear control and observation, kinematics and dynamics of manipulation.

Current Research:

Dr. Jia's main research objective is to develop algorithms that would enable arobot to effectively execute real world tasks that involve sensing, localizing, grasping, and manipulating of physical objects. His investigation into robot dexterity has focused on understanding computational and control issues in manipulation tasks. A major of this study is the development of algorithms for dynamic retrieval of geometric information such as shape and pose, and of mechanical information such as motion and force, and the effective use of such information in executing specific tasks.

Dr. Jia has been studying the localization, recognition, and reconstruction of curved shapes using minimum tactile information. This study is aimed at understanding the basic computational principles and limitations of touch sensing. From a more general perspective, he is interested in the design of geometric and control algorithms for dexterous manipulation and strategies for robot sensing that are efficient, reliable, and easily integrable into manipulation operations.

Details of Dr. Jia's research can be found at http://www.cs.iastate.edu/~jia

Representative Publications:

Ibrayev, R.and Jia, Y-B.(2006). Surface recognition by registering data curves from touch.Accepted to the IEEE/RSJ International Conference on Intelligent Robots and Systems, Beijing, PRC, Oct 9-15, 2006.

Jia, Y-B,Mi, L. and Tian, J. (2006). Surface patch reconstruction via curve sampling. In Proceedings of the IEEE International Conference on Robotics and Automation, pp. 1371-1377, Orlando, FL, May 16-18, 2006.

Ibrayev, R.and Jia, Y-B.(2005). Semi-differential invariants for tactile recognition of algebraic curves. International Journal of Robotics Research, vol. 24, no. 11, pp. 951-969.

Jia, Y-B. (2005). Localization of curved parts through continual touch. IEEE Transactions on Robotics, vol. 21, no. 4, pp. 726-733.

Jia, Y-B. (2004). Computation on parametric curves with an application in grasping. International Journal of Robotics Research, vol. 23, no. 7-8, pp. 825-855.

Jia, Y-B. andMi, L. (2004). High precision contour tracking with a joystick sensor. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 804-809, Sendai, Japan, Sep 28 - Oct 2, 2004.

Jia, Y-B. (2003). Contact sensing for parts localization: sensor design and experiments. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 516-522, Las Vegas, NV, Oct 27-31, 2003.

Jia, Y-B. and Erdmann, M. (1999).Pose and Motion from Contact. International Journal of Robotics Research, 18(5):466-490.

Jia, Y-B. and Erdmann, M. (1998).Local Observability of Rolling. In Robotics: The Algorithmic Perspective, P.K. Agarwal et al. (eds.), pp. 251-263, A. K. Peters, Boston.

Jia, Y-B. and Erdmann, M. (1996). Geometric Sensing of Known Planar Shapes. International Journal of Robotics Research, 15(4):365-392.

 


JACK H. LUTZ, Professor of Computer Science

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

Major Interests:

Computational Complexity: structure of complexity classes, resource-bounded measure and dimension, and complexity in analysis. Algorithmic Information and Randomness: computational randomness, constructive dimension, Kolmogorov complexity, prediction, finite-state dimension, and algorithmic fractal geometry. Nanoscale Self-Assembly: information flow, universal computation, zeta-dimension, and randomness in self-assembling fractal structures.

Current Research:

Dr. Lutz is currently focused on computational complexity, algorithmic information theory, and nanoscale self-assembly. In all three of these areas, I collaborate extensively with graduate students, postdoctoral researchers, and faculty, both at ISU and elsewhere.In computational complexity he is investigating the structure of complexity classes (deterministic, non-deterministic, and probabilistic) using resource-bounded measure and dimension, complexity-theoretic generalizations of Lebesgue measure and fractal dimension that he has developed.

Current work focuses on derandomization, weak completeness, circuit-size complexity, strong hypotheses, and the type-2 foundations of resource-bounded measure and dimension.We are also investigating computability and complexity in geometric measure theory, which is the part of mathematical analysis that deals with the fine-scale properties of fractals, particle trajectories, and other dynamical processes in real Euclidean space.

In algorithmic information theory Dr. Lutz is studying randomness,Kolmogorov complexity, and constructive dimension, with applications in algorithmic prediction, geometric measure theory, and games. His research group isalso investigating finite-state dimension, especially in connection with Borel normal numbers and data compression. Their newest research area is nanoscale self-assembly.Here they are investigating the algorithmic self-assembly of fractal structures in the DNA tile assembly model of Seeman, Winfree, and Rothemund.They are especially interested in zeta-dimension, which is the appropriate measure of the fractal dimensions of such structures; bandwidth as a physical complexity measure; the apparent tradeoff between zeta-dimension and efficiency of computation in self-assembly; and randomized self-assembly.

Representative Publications:

Gu, X., Lutz, J. and Mayordomo, E. (2006). "Points on Computable Curves", Proceedings of the the Forty-Seventh Annual IEEE Symposium on Foundations of Computer Science (Berkeley, CA, October 22-24, 2006), IEEE Computer Society Press, pp. 469-474.

Doty, D., Lutz, J., and Nandakumar, S. (2006). "Finite-State Dimension and Real Arithmetic", Proceedings of the Thirty-Third InternationalColloquium on Automata, Languages, and Programming} (Venice, Italy, July 10-14, 2006), Springer-Verlag, pp. 537-547.

Gu, X.and Lutz, J."Dimension Characterizations of Complexity Classes", Computational Complexity, to appear.

Gu, X., Lutz, J. and Moser, P."Dimensions of Copeland-Erdos Sequences", Information and Computation, In press.

Athreya, K., Hitchcock,J., Lutz, J. and Mayordomo, E. "Effective Strong Dimension in Algorithmic Information and Computational Complexity", SIAM Journal on Computing, In press.

Hitchcock, J., Lutz, J. and Terwijn, S. (2007). "The Arithmetical Complexity of Dimension and Randomness", ACM Transactions on Computational Logic, In press.

Hitchcock, J. and Lutz, J. (2006). "Why Computational Complexity Requires Stricter Martingales", Theory of Computing Systems 39, pp. 277-296.

Fortnow, L.and Lutz, J. (2005). "Prediction and Dimension", Journal of Computer and System Sciences 70, pp. 570-589.

Hitchcock, J., Lutz, J. and Mayordomo, E. (2004). "Scaled Dimension andNonuniform Complexity", Journal of Computer and System Sciences 69, pp. 97-122.

Dai, J., Lathrop, J., Lutz, J.and Mayordomo, E. (2004). "Finite-State Dimension", Theoretical Computer Science 310, pp. 1-33.

Lutz, J. (2003)."The Dimensions of Individual Strings and Sequences", Information and Computation 187, pp. 49-79.

Lutz, J. (2003)."Dimension in Complexity Classes", SIAM Journal on Computing 32, pp. 1236-1259.

 


ROBYN LUTZ, Professor of Computer Science

Ph.D. 1980, Spanish, University of Kansas

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

Major Interests:

Safety-critical product lines, requirements engineering, software safety, formal methods for specification and analysis, fault monitoring and recovery, software engineering.

Current Research:

Dr. Lutz's research is in software engineering, the part of computer science that studies how to develop better software systems. Her research contributions have been in two overlapping areas of software engineering:(1) how to build safe systems and (2) how to specify and analyze requirements for those systems.

Safety-critical software is software that can cause, or prevent, a hazardous situation or damage to life, property, or mission. Examples of safety-critical software include the software in medical imaging systems, in autonomous vehicles, and in spacecraft control systems. Dr. Lutz's research in the area of software safety has focused on safety-critical software product lines.A product line is a set of highly similar systems with a few key variations. Some examples of safety-critical software product lines that she has worked with are: flight-instrumentation displays (such as pilots use in the cockpit), interferometers (spaceborne, astronomical telescopes), medical-imaging systems (used by physicians to create computer images of patients' organs), and implantable medical devices (such as pacemakers and defibrillators).Dr. Lutz's key contributions in this area have been to extend software-safety techniques that were traditionally applied only to single systems to handle the new product lines of systems. The purpose of these extensions is to allow safety analyses to become reusable assets within a product line. By expanding software-safety techniques to product lines, and by formalizing the caveats on such reuse, Dr. Lutz and her research group hope to reduce the cost of doing safety analysis on product lines and speed up time-to-market of new products in the line. More importantly for safety-critical product lines, these techniques enhance the thoroughness and rigor of the safety analyses performed.

Dr. Lutz's work on requirements analysis for safety critical systems has focused on methods that enable developers to more accurately describe and rigorously analyze the requirements and design for safety-critical software. Historically, many failures of software have been due to an inadequate understanding of the software requirements by the developers. The specifications of what the software had to do were incomplete or inconsistent in some way that hindered safe, correct software from being built.One of Dr. Lutz's key contributions in this area has been to create formal models for the fault-protection software that detects and isolates system failures, and reconfigures the system to recover from them. More recently, she and collaborators at Jet Propulsion Laboratory and NASA Ames have developed a tool-supported, development approach for diagnosing and responding to contingencies (operational situations with mission risk) in a formal model of an unpiloted aerial vehicle.

A second key contribution has been the development by Dr. Lutz of Bi-Directional Safety Analysis, which systematically combines two distinct analysis methods to search for missing or incomplete requirements in software systems. Many of the results in this area have been applied to NASA spacecraft. With support from the NSF, Dr. Lutz and her students have extended this technique to product lines. She has also investigated a product-line approach to the development of distributed multi-agent systems (such as fleets of autonomous vehicles). Other collaborative applications have been to automatic construction of monitors for intrusion detection and to guiding user goal-refinement when a desired web-service composition fails.

A third key contribution has been to empirically confirm what was long-suspected:that misunderstood requirements and interfaces cause failures during testing and operations. Dr. Lutz and Carmen Mikulsi did this by identifying and describing the patterns of requirements omissions and requirements misunderstandings that escaped testing to manifest themselves during flight. These empirical investigations enabled the pinpointing of some specific, common weaknesses in the software requirements specification process. Dr. Lutz, in collaboration with her students, has developed solutions that target these specific areas. Supported by NSF, Dr. Lutz's research group and Dr. John Knight's research group at the University of Virginia have experimentally applied automated analysis results from software problem reports (generated during testing) to iteratively improve the linguistic domain modeling of requirements specifications.

Additional details of Dr. Lutz's research can be found at www.cs.iastate.edu/~rlutz

Representative Publications:

Lutz, R., Patterson-Hine, A., Nelson, S., Frost, C., Tal, D., and Harris, R."Using Obstacle Analysis to Identify Contingency Requirements on an Unpiloted Aerial Vehicle", Requirements Engineering Journal, to appear.

Lutz, R., Patterson-Hine, A., and Bajwa, A. "Tool-Supported Verification of Contingency Software Design in Evolving, Autonomous Systems", Proc. 7th IEEE International Symposium on Software Reliability Engineering (ISSRE 2006). Nov. 7-10, 2006, Raleigh, NC.

Dehlinger, J. and Lutz, R. (2006). "PLFaultCat:A Product-Line Software Fault Tree Analysis Tool", Automated Software Engineering, 13(1): pp. 169-193.

Dehlinger, J. and Lutz, R. (2005). "A Product-Line Approach to Promote Asset Reuse in Multi-Agent Systems", SELMAS 2005, LNCS vol. 3914, Ed. R. Choren.

Feng, Q. and Lutz, R.. "Bi-Directional Safety Analysis of Product Lines", Journal of Systems and Software, 78(2), Nov. 2005, pp. 111-127.

Padmanabhan, P. and Lutz, R.. "Tool-Supported Verification of Product Line Requirements, Automated Software Engineering, 12(4), Oct., 2005, pp. 447-485.

Schwanke, R. and Lutz, R.. "Experience with Architectural Design of a Modest Product Family," Software Practice and Experience, 34(13), Nov. 2004, pp. 1273-1296.

Lutz, R. and Mikulski, C. "Empirical Analysis of Safety-Critical Anomalies during Operations," IEEE Transactions on Software Engineering," vol. 30, no., 3, March, 2004, pp. 172-180.

Lutz,R. (2000). "Software Engineering for Safety:A Roadmap,'' in The Future of Software Engineering, 2000, ed. A. Finkelstein, ACM,Invited Chapter, pp. 213-224.

Easterbrook, S., Lutz, R., Covington, 'R., Kelly, J.,Ampo, Y. and Hamilton, D. "Experiences Using Lightweight Formal Methods for Requirements Modeling," IEEE Transactions on Software Engineering, Vol. 24, 1, Jan., 1998, pp. 4-14.

Lutz, R. and Wong, J. "Detecting Unsafe Error Recovery Schedules,'' IEEE Transactions on Software Engineering, Vol. 18, 8, Aug., 1992, pp. 749-760.

 


DIMITRIS MARGARITIS, Assistant Professor of Computer Science

Ph.D. 2003, Computer Science, Carnegie Mellon University

Major Interests:

Probabilistic modeling, methods for managing and reasoning with uncertainty/indeterminacy in Artificial Intelligence and other applications, Bayesian networks, Markov networks, data mining, machine learning, cross-disciplinary applications of these in bioinformatics, econometrics, very large databases and other domains.

Current Research:

Dr. Margaritis's current research is on algorithms for learning the structure of Bayesian networks and applying them to real-world application domains where modeling uncertainty might be beneficial.For example, it turns out that approximate query answering in very large databases can be done quickly using a sufficiently complex model of the database---in this case a Bayesian network. He would also like to explore capturing and modeling information about influences by statistical means in bioinformatics domains such as protein structure prediction. Dr. Margaritis's long-term vision is to develop algorithms and representations that help researchers gain insights into their research domains by automatically constructing probabilistic models of them from data.

Representative Publications:

Bromberg, F., Margaritis, D. and Honavar, V. (2006). Efficient Markov Network Structure Discovery from Independence Tests.SIAM International Conference on Data Mining (SDM).

Margaritis, D. (2005). Distribution-Free Learning of Bayesian Network Structure in Continuous Domains.National Conference on Artificial Intelligence (AAAI).

Yaramakala, S. and Margaritis, D. (2005). Speculative Markov Blanket Discovery for Optimal Feature Selection.IEEE International Conference on Data Mining (IEEE ICDM).

Cheng, H., Sen, T. Z. , Kloczkowski, A., Margaritis, D.and Jernigan, R. L.. Prediction of Protein Secondary Structure by Mining Fragments Database, Polymer.in press.

Margaritis, D. and Thrun, S. (2001). A Bayesian Multiresolution Independence Test for Continuous Variable. Uncertainty in Artificial Intelligence (UAI).

Margaritis, D., Faloutsos, C. and Thrun, S. (2001). NetCube: A Scalable Tool for Fast Data Mining and Compression. International Conference on Very Large Databases (VLDB).

Margaritis, D. and Thrun, S. (1999). Bayesian Network Induction via Local Neighborhoods. Neural Information Processing Systems (NIPS).

Moghaddam, D., Biermann, H. and Margaritis, D. (2001). Regions-of-Interest and Spatial Layout for Content-Based Image Retrieval. Journal of Multimedia Tools and Applications, Kluwer Academic Publishers, Vol. 14, No. 3, 2001.

Margaritis, D. and Thrun, S. (1998). Learning to Locate and Object in 3D Space from a Sequence of Camera Images. International Conference in Machine Learning (ICML).

Waldherr, S., Thrun, S.,Romero, R. and Margaritis, D. (1998). Template-Based Recognition of Pose and Motion Gestures on a Mobile Robot. National Conference on Artificial Intelligence (AAAI).

 


LES MILLER, Professor of Computer Science

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

Research Areas

Bioinformatics and Computational Biology, e-Government, Human Computer Interaction, Data Warehouses, Information Integration and Information Retrieval, Database Systems, Information Security, Software Systems

Research Statement

Dr. Miller's current research is focused on interface design issues for handheld computers used in spatial data collection within Bureau of Census's decennial census. Other current work in human computer interaction aims to enhance the use of the Internet by the elderly. His workin computational biology is focused onthe development of graph models for storing and analyzing biological networks.His on knowledge Management looks at the development of distributed knowledge management systems that use business process-based topic maps as knowledge hubs. Work on organizational memory is focused on the capture of organizational semantics and the integration of memory artifacts into the organization's knowledge base.

Selected Publications

Miller, L., Nilakanta, S., Song, Y., Zhu, L. and Hua, M. (2007). Knowledge Management: Using Topic Maps in Organizational Memory. Hawaiian International Conference on System Sciences.pp. 204b-

Miller, L., Ding, J. and Nusser, S. (2007). An Accuracy Model for Relational Databases. Accepted to the ISCA 22nd International Conference on Computers and Their Applications. In press.

Nilakanta, S., Miller, L., Song, Y. and Zhu, L. (2007). Supporting Topic Maps in an Organizational Memory Web Server. Information Resources Management Association International Conference.In press.

Helmer, G., Wong, J., Slagell, M., Honavar, V., Miller, L., Wang, Y., Wang, X. and Stakhanova, N. (2007). Software Fault Tree and Colored Petri Net Based Specification, Design and Implementation of Agent-Based Intrusion Detection Systems. To appear in the International Journal of Information and Computer Security.

Wang, Y., Behera, S., Wong, J., Helmer, G., Honavar, V., Miller, L., and Lutz, R. (2006). Towards the automatic generation of mobile agents for distributed intrusion detection systems. Journal of Systems and Software79 (1): 1-14.

Nilakanta, S., Miller, L. and Zhu, D. (2006). Organization Memory Management: Technological and Research Issues. Journal of Database Management. Vol. 17 No. 1 pp. 85-94.

Tsai, H-J., Miller, L., Ming, H. and Nusser, S. (2006). Combining Spatial Data from Multiple Data Sources. ISCA 19th International Conference on Computer Applications in Industry and Engineering. Pages 89-94.

Zhang, J.,Cook, D. and Miller, L. (2005). Limn Matrix: A Tool for Visualizing Large, Distributed, High-Dimension Data Sets. 17th International Conference of Computer Applications in Industry and Engineering. Honolulu, HI. pp. 263-268

Miller, L., Zou, B., Hua, M. and Nusser, S. (2004). Supporting a Virtual Office Environment for Federal Agency Field Operations. The Third International Conference on Politics and Information Systems: Technologies and Applications (PISTA '04). Orlando, FL. Pages 84-88.

 


ANDREW S. MINER, Associate Professor of Computer Science

Ph.D. 2000, Computer Science, College of William and Mary

Major Interests:

Performance and reliability analysis of systems;model checking and formal methods;binary decision diagrams (and variants);analysis algorithms; Petri nets and stochastic modeling; tool development.

Current Research:

Dr. Miner's primary research goal is to develop techniques for analyzingcomplex discrete-event systems (including computer communication networks, multi-threaded software, network protocols, and others). He has worked in the areas of model checking and performance evaluation, and is particularly interested in techniques that are applicable to both of these areas. Dr. Miner also works on developing software tools that incorporate these techniques. See http://www.cs.iastate.edu/~asminer for details.

Model checking is the process of determining if a system, described as a (usually nondeterministic) model, satisfies some properties. These properties are expressed using an appropriate logic, such as the temporal logics LTL or CTL. If the system model describes a finite state machine, then the model checking problem is decidable. In practice, however, the finite state machines can be extremely large. Researchers use a variety of techniques to overcome this; Dr. Miner has focused past efforts on techniques that utilize a data structure called decision diagrams. He has made several contributions in this area developing improved reachability set generation algorithms (a core problem in model checking) for decision diagrams, especially for models of asynchronous systems. Dr. Miner is currently working with Dr. Basu to apply these techniques to multi-threaded software.

If a system is described using a stochastic model, rather than a nondeterministic model, then the model ultimately generates a stochasticprocess. Properties of the system can then either be queried (e.g., "What is the probability that a packet is lost") or expressed using a stochastic logic such as pCTL or CSL (e.g., "The probability of a lost packet is less that 10^-6"). In either case, these properties are determined by analyzing the underlying stochastic process, which is typically a Markov chain. Dr. Miner has contributed to this area by adapting decision diagram algorithms used for model checking for use with Markov chains.

Dr. Miner is a co-designer and developer of the software tool SMART (Stochastic Model-checking Analyzer for Reliability and Timing), which contains implementations of traditional as well as state-of-the-art techniques in model checking and performance evaluation. The tool was designed for instructional, research, and industrial use.

Representative Publications:

Miner, A. Saturation for a general class of models. IEEE Transactions on Software Engineering. In press.

Ciardo, G., Jones, R.,Miner, A. and Siminiceanu, R. (2006). Logical and stochastic modeling with SMART. Performance Evaluation, 63 (6): 578-608.

Miner, A. and Cheng, S. (2004). Improving efficiency of implicit Markov chain state classification. In Proceedings of QEST 2004, pp 262-271.

Miner, A.and Parker, D. (2004). Symbolic representations and analysis of large state spaces. In "Validation of Stochastic Systems" (Springer Verlag, 2004),LNCS 2925, pp 296-338.

Miner, A (2004). Implicit GSPN reachability set generation using decision diagrams. Performance Evaluation, 56 (1-4): 145-165.

Ciardo, G.,Forno, M., Grieco, P. and Miner, A. (2003). Comparing implicit representations of large CTMCs. In Proceedings of NSMC 2003, pp 323-327.

Miner, A., Ciardo, G. and Donatelli, S. (2000).Using the exact state space of a large structured Markov model to compute approximate stationary measures.In Proceedings of ACM SIGMETRICS 2000, pp 207-216.

Ciardo, G. and Miner, A. (1999).A data structure for the efficient Kronecker solution of GSPNs. In Proceedings of PNPM'99, pp 22-3.

Miner, A. and Ciardo, G. (1999). Efficient reachability set generation and storage using decision diagrams. In Proceedings of ICATPN 1999 (LNCS 1639), pp 6-25.

 


GURPUR M. PRABHU, Associate Professor of Computer Science

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

Major Interests:

Parallel processing, information integration and information retrieval, intelligent computing, and other interesting scientific problems.

Current Research:

Dr. Prabhu's work on generating random numbers for parallel computers has led to an efficient parallel random number generator (O (1) parallel time per generation of one number on each processor).

Dr. Prabhu's work, in collaboration with former Ph.D. student Srinivas Aluru, focused on analysis of the fastest known algorithm, namely, Greengard's algorithm, for the N-body problem - the problem of simulating the motion of N particles under the influence of mutual force fields based on an inverse square law. This problem has applications in several domains including radiosity methods in computer graphics, astrophysics, molecular dynamics, fluid dynamics, and numerical complex analysis. Greengard, whose Ph.D. thesis won the ACM distinguished dissertation award in 1987, claimed to compute the pairwise interactions in O(N) time per iteration. Dr. Prabhu and Aluru's analysis of Greengard's algorithm showed that the Greengard's algorithm is not O(N) as claimed.

Dr. Prabhu's work with two doctoral students, Naresh Nayar and Milton Wikstrom focused on the applications of high-performance techniques in the areas of weather modeling and computational chemistry. Another student that Dr. Prabhu mentored, Diane Rover, worked at the Scalable Computing Laboratory and her work on visualization of program performance and the SLALOM benchmark have received national research awards. A recent doctoral student, Rajat Todi, used the HINT benchmark to evaluate file access patterns for realistic I/O workloads in cluster environments. Along with doctoral student Babak Forouraghi, Dr. Prabhu studied the design of learning algorithms for flaw classification of materials used in nondestructive evaluation, drawing on approaches from multiobjective optimization, fuzzy logic, machine learning, and multivariate statistics.

Dr. Prabhu's current interests center around semantic-based search techniques for information retrieval and processing. Dr. Prabhu is also exploring some long-standing open problems in the area of inertial frames and paradoxes in special relativity.

Representative Publications:

Prabhu, G., Aluru, S. and Gustafson, J. (1992). "A random number generator for parallel computers,"Parallel Computing, 18, pp. 839-847.

Prabhu, G., Forouraghi, B. and Schmerr, L. (1994). "Fuzzy multiobjective optimization with multivariate regression trees," Third International Conference on Fuzzy Systems, pp. 1400-1405.

Prabhu, G., Forouraghi, B. and Schmerr, L.(1994). "Induction of multivariate regression trees for design optimization," Twelfth AAAI National Conference on Artificial Intelligence, pp. 607-612.

Prabhu, G., Aluru, S., Gustafson, J.and Sevilgen, F. (1998). "Distribution-independent hierarchical algorithms for the N-body problem," Journal of Supercomputing, 12, pp. 303-323.

Prabhu, G., Wang, H., Takle, E., and Shen, J. M. (2000). "Performance evaluation of climate simulation on a cluster of networked workstations," International Conference on Parallel and Distributed Processing Techniques and Applications, pp. 2007-2013, CSREA Press.

Prabhu, G. and Balakrishnan, P. (2003). "Programmable access to distributed data: Design of Semantic Bridge," 2nd IASTED International Conference on Communications, Internet, and Information Technology, Scottsdale, Arizona, pp. 589-594.

Prabhu, G. and Iyer, C. (2006). "Reversal in time order of interactive events: collision of inclined rods," Eur. J. Phys. 27,pp. 819-824.

Prabhu, G. and Iyer, C.(2006). "Differing perceptions on the landing of the rod into the slot," (with Chandru Iyer), accepted in Am. J. Phys., 74 (11),pp. 998-1001.

Prabhu, G. and Iyer, C. (2007). "Lorentz transformations with arbitrary line of motion," (with Chandru Iyer), accepted in Eur. J. Phys. 28 (2), pp. 183-190, To appear.

 


HRIDESH RAJAN, Assistant Professor of Computer Science

Ph.D. 2005, Computer Science, University of Virginia

Major Interests:

Software engineering, modularity in software design, science of design, component integration, service-oriented architectures, programming language design and implementation, aspect-oriented languages, specification languages, static and dynamic analysis, testing and verification, program comprehension

Current Research:

Dr. Rajan's research on programming language design and implementation has focused on the design and implementation of aspect-oriented programming (AOP) languages. AOP has shown the potential to improve the ability of software architects to devise effective modularizations for complex systems, leading to savings in cost, schedule, and quality. In the Nu project (See http://www.cs.iastate.edu/~nu) Dr. Rajan and his students Robert Dyer and Harish Narayanappa are exploring intermediate language designs and corresponding virtual machine extensions to bring design modularity at the object code level for aspect-oriented languages. The potential impacts of this project include better compatibility with the existing tool chain, better run-time performance, cross AO language compatibility, improved pointcut expressivity, and efficient run-time weaving support. In collaboration with William G. Griswold from University of California, San Diego and Kevin J. Sullivan from University of Virginia, Dr. Rajan developed the notion of crosscut programming interfaces (XPI) to decouple aspects that use aspect-oriented advising from the details of advised code. XPI's provide a better encapsulation for changeable implementation details. The abstract design concerns that were hidden earlier in the program structures and syntactic pointcut elements were revealed in a principled way. In collaboration with Kevin J. Sullian, Dr. Rajan's Eos project (See http://www.cs.iastate.edu/~eos) has advanced aspect-oriented languages by developing the notion of general-purpose aspect instantiation and selective advising for aspects, and a significantly simplifying unification of aspect and object-oriented programming. These advances led to improved modularity of component integration concerns.

Dr. Rajan's work on specification and verification, in collaboration with Ph.D. student Youssef Hanna and his colleague Wensheng Zhang, is focused onspecifying and verifying cryptographic protocols for sensor networks in his Slede project (See http://www.cs.iastate.edu/~slede). Applications of sensor networks are numerous from military to environmental research. By providing mechanisms to find cryptographic errors in the security protocols for sensor networks this research program is improving the reliability of these networks, making a direct impact on all areas where these networks are utilized.

Program Comprehension

Dr. Rajan's work on program comprehension, In collaboration with his Ph.D. Student Juri Memmert, is focused on approaches and tools for automatic or semi-automatic generation of concern models from source code in his Osiris project (See http://www.cs.iastate.edu/~design/osiris/). Concern models are abstract representation of the system that eases better comprehension of large software systems designed to help enhance the comprehensibility of large software systems.

Representative Publications:

Rajan, H., Dyer, R., Hanna, Y. andNarayanappa, H.(2006). Preserving Separation of Concerns through Compilation.Software Engineering Properties of Languages and Aspect Technologies (SPLAT 06), A workshop affiliated with AOSD 2006, Bonn, Germany.

Rajan, H. and Sullivan, K. (2005). Classpects: Unifying Aspect- and Object-Oriented Language Design. In: Proceedings of the 27th International Conference on Software Engineering (ICSE 2005), 15-21 May 2005, St. Louis, Missouri, USA.

Rajan R. and Sullivan, K.(2003). Eos: Instance-Level Aspects for Integrated System Design.In: Proceedings of the 2003 Joint European Software Engineering Conference and ACM SIGSOFT Symposium on the Foundations of Software Engineering (ESEC/FSE 2003), Helsinki, Finland.

Rajan, H. and Sullivan, K.(2005). Aspect Language Features for Concern Coverage Profiling. In: Proceedings of the Fourth International Conference on Aspect-Oriented Software Development (AOSD 2005), 14-18 March, 2005, Chicago, IL, USA.

Griswold, W., Sullivan, K., Song, Y., Shonle, M., Tewari, N., Cai, Y. and Rajan, H. (2006). Modular Software Design with Crosscutting Interfaces. IEEE Software, Special Issue on Aspect-Oriented Programming, Jan/Feb 2006.

Sullivan, K., Griswold, W., Song, Y., Shonle, M., Tewari, N., Cai, Y. and Rajan, H. (2005). Information Hiding Interfaces for Aspect-Oriented Design.In: Proceedings of the Joint 10th European Software Engineering Conference and 13th ACM SIGSOFT Symposium on the Foundations of Software Engineering (ESEC/FSE 2005), 5-9 Sept 2005, Lisbon, Portugal.

 


LU RUAN, Assistant Professor of Computer Science

Ph.D. 2001, Computer Science, University of Minnesota - Twin Cities

Major Interests:

Computer Networks, Optical Networks.

Current Research:

IP over WDM is being envisioned as the architecture for the next generation Internet. In this architecture, high-speed IP routers are interconnected by intelligent optical core networks. Survivability in these networks is essential since the networks carry a high volume of traffic and a single link/node failure will cause tremendous service loss. Dr. Ruan's current research focuses on the design of fast and capacity efficient protection/restoration schemes in both the IP layer and the WDM layer to recover from link/node failures. In addition, she is interested in developing techniques to integrate the recovery schemes in the two layers seamlessly and efficiently.

Representative Publications:

Ruan, L. and F. Tang, F. (2006). Survivable IP Network Realization in IP-over-WDM Networks under Overlay Model. Computer Communications, vol. 29, no 10, pages 1772-1779, June 2006.

Liu, C. and Ruan, L. (2006).p-Cycle Design in Survivable WDM Networks with Shared Risk Link Groups (SRLGs). Photonic Network Communications, vol. 11, no. 3, pages 301-311, May 2006.

Ruan, L., Luo, H., and Liu, C. (2004) A Dynamic Routing Algorithm with Load Balancing Heuristics for Restorable Connections in WDM Networks. IEEE Journal on Selected Areas in Communications, vol.22, no. 9, pages 1823-1829, November 2004.

Liu, C. and Ruan, L. (2006). Dynamic Provisioning of Survivable Services Using Path-Segment Protecting p-Cycles in WDM Networks. In: Proceedings of Int'l Conf. on Computer Communications and Networks, Arlington, Virginia, USA, October 2006. (Best paper candidate.)

Liu, C. and Ruan, L. (2005). Logical Topology Augmentation for Survivable Mapping in IP-over-WDM Networks. In:Proceedings of IEEE Globecom, volume 4, pages 1885 - 1889, St. Louis, MO, USA, November/December 2005.

Liu, Z. and Ruan, L. (2005). Reducing Restoration Blocking in WDM Optical Networks. In: Proceedings of ICCCN 2005, pages 323-330, San Diego, CA, October 2005.

Ruan, L. and Tang, F. (2005). Dynamic Establishment of Restorable Connections using p-Cycle Protection in WDM Networks. In: Proceedings of Broadnets 2005, pages 147-154, Boston, MA, October 2005.

Ruan, L. and Liu, Z. (2005). Upstream Node Initiated Fast Restoration in MPLS Networks. In: Proceedings of IEEE ICC 2005, pages 959-964, Seoul Korea, May 2005.

Liu, C. and Ruan, L. (2004). Finding Good Candidate Cycles for Efficient p-Cycle Network Design. In: Proceedings of the Thirteenth International Conference on Computer Communications and Networks (ICCCN), pages 321-326, Chicago, IL, Oct. 2004.

Ruan, L. and Du, D-Z. (eds.), Optical Networks-Recent Advances, Kluwer Academic Publishers, 2001.

 


GIORA SLUTZKI, Professor of Computer Science

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

Major Interests:

Algorithms and Complexity, Game Theory, Logic, Automata Theory.

Current Research:

Dr. Slutzki is currently working on complexity of some problems in abstract algebra and graph theory. He also works on bioinformatics algorithms, ranking of alternatives,problems in pursuit-evasion in polygons, and algorithmic problems in game theory.

Representative Publications:

Volij, O and Slutzki, G. (2006). Scoring of Web Pages and Tournaments - Axiomatizations. Journal of Social Choice and Welfare, Vol. 26, No. 1, pp.75-92.

Volij, O and Slutzki, G. (2005).Ranking Participants in Generalized Tournaments. International Journal of Game Theory, 33(2)(2005), pp. 255-270.

Slutzki, G., Simov, B. and LaValle, S.(2002). A Complete Pursuit-Evasion Algorithm for Two Pursuers Using Beam Detection. In the proceedings of IEEE International Conference on Robotics and Automation (ICRA '02), May 2002, Washington, DC, USA.

Slutzki, G. and Bergman, C. (2002). Computational Complexity of Some Problems Involving Congruences on Algebras. Theoretical Computer Science, 270, pp. 591-608.

Slutzki, G., Fernandez-Baca, D. and Seppalainen, T.(2002). Lower Bounds for Parametric Sequence Comparison" .Special Issue of Discrete Applied Mathematics (DAM), 118(3), pp. 181-199. Extended Abstract appeared in SPIRE '99.

Slutzki, G. and Bergman, C. Computational Complexity of Generators and Nongenerators in Algebra. To appear in International Journal of Algebra and Computation.

Slutzki, G. Mobasher, B., Pigozzi, D. and Vautsadakis, G. (2000).A Duality Theory for Bilattices. Algebra Universalis, 43, pp. 109-125.

Slutzki, G., Simov, B. and LaValle, S.(2000). An Algorithm for Searching a Polygonal Region with a Flashlight.. 16th ACM Symposium on Computational Geometry (SoCG '00), June 2000, Hong Kong. Proceedings, pp. 260-269. To appear in a Special Issue of the International Journal of Computational Geometry and Applications (IJCGA).

Slutzki, G., Fernandez-Baca, D. and Seppalainen, T.(2000).Parametric multiple sequence alignment and phylogeny construction. 11th Annual Symposium on Combinatorial Pattern Matching (CPM '00), June 2000, Montreal, Canada. Springer Verlag, LNCS 1848, pp. 69-83. To appear in Journal of Discrete Algorithms.

Slutzki, G. and Bergman, C. (2000). Complexity of Some Problems Concerning Varieties and Quasi-Varieties of Algebras. SIAM Journal on Computing, 30 (2), pp. 359-382. Extended Abstract appeared in 16th STACS (1999).

Slutzki, G., Juedes, D. and Bergman, C. (1999).Computational Complexity of Term-Equivalence. International Journal of Algebra and Computation 9 (1), pp. 113-128.

 


GUANG SONG, Assistant Professor of Computer Science

Ph.D. 2003,Computer Science, Texas A&M University

Major Interests:

Bioinformatics and Computational Biology, Robotics, Computational Geometry, Algorithms

Current Research:

Dr. Song's research interests spread over several disciplines: physics, robotics, computer science, and biology. One goal of his research is to gain a deeper understanding of life and its mechanisms, which orchestrate various components to function together, at different levels. His current research focuses on understanding the mechanisms of protein functions, for example, how does the structure of a protein facilitate the realization of its functions? How does the binding a ligand open up an ion channel at a remote site? How does a protein fold? His work thus involves physically and structurally based modelings and simulations.His research interests also include motion planning, robotics, quantum computing, virtual reality, and haptic input.

Representative Publications:

Lei Yang, Guang Song, Alicia Carriquiry and Robert L. Jernigan. Close Correspondence between the Essential Protein Motions from Principal Component analysis of Multiple HIV-1 Protease Structures and Elastic Network Modes. Structure, Cell Press. Vol. 16. No. 2. pp. 321-330, 2008.

Guang Song and Robert L. Jernigan. vGNM: a Better Model for Understanding the Dynamics of Proteins in Crystals. Journal of Molecular Biology. Vol. 369. No.3. pp. 880-93, 2007.

Lei Yang, Guang Song, and Robert L. Jernigan. How Well Can We Understand Large-Scale Protein Motions Using Normal Modes of Elastic Network Models?. Biophysical Journal. Vol. 93. No. 3. pp. 920-9, 2007.

Song, G. and Jernigan, R. (2006). An Enhanced Elastic Network Model to Represent the Motions of Domain-Swapped Proteins. Proteins. Vol. 63. No. 1. pp. 197-209.

Thomas, S., Song. G., and Amato, N. (2005). Protein folding by motion planning. Physical Biology. Vol. 2. No. 4. pp. S148-55.

Song, G.and Klappenecker, A. (2004). Optimal Realizations of Simplified Toffoli Gates. Journal of Quantum Information and Computation. Vol. 4. No. 5. pp. 361-372.

Song. G. and Amato, N.(2004). A Motion Planning Approach to Folding: From Paper Craft to Protein Folding. IEEE Transactions on Robotics and Automation. Vol. 20. No. 1. pp. 60-71.

Amato, N., Dill, K. and Song, G.(2003). Using Motion Planning to Map Protein Folding Landscapes and Analyze Folding Kinetics of Known Native Structures. Journal of Computational Biology. Vol. 10. No. 3-4. pp. 239-256.

Song, G.and Klappenecker, A. (2003). Optimal Realizations of Controlled Unitary Gates. Journal of Quantum Information and Computation. Vol. 3. No. 2. pp. 139-155.

Song. G. and Amato, N.(2001). Using Motion Planning to Study Protein Folding Pathways. the 5th ACM International Conference on Computational Molecular Biology (RECOMB), Montreal, Canada. pp. 287-296.

Bayazit, O. B., Song. G. and Amato, N.(2001). Enhancing Randomized Motion Planners: Exploring with Haptic Hints. Autonomous Robots. Vol. 10. No. 2. pp. 163-174.

 


WALLAPAK TAVANAPONG, Associate Professor of Computer Science

Ph.D. 1999, Computer Science, University of Central Florida

Major Interests:

Content analysis for medical images and videos, multimedia databases, distributed caching systems for multimedia data, multimedia communications and operating systems, peer-to-peer systems, quality of service support, mobile data management.

Current Research:

Dr. Tavanapong investigates database management systems for videos captured from medical procedures, especially from endoscopic procedures such as colonoscopy, upper endoscopy, just to name a few. Such a system will be useful for improving endoscopic research, training, and education and has a great potential to improve patient care as millions of these procedures are performed yearly in the US alone. The key challenges from computer science perspectives are 1) how to design an algorithm that effectively and efficiently recognizes important contents such as different types of abnormality and instruments used in medical procedures, 2) how to represent and organize these contents such that they are quickly accessible via a keyword query or a query by image or video example, and 3) how to present the contents to users in a user-friendly manner. Several software packages have also been developed and used in a hospital. This research is a joint work with Professor Johnny Wong at Iowa State University, Professor Piet de Groen at Mayo Clinic Rochester, and Professor JungHwan Oh at the University of North Texas.

Dr. Tavanapong's research in multimedia and communications has investigated distributed caching systems for multimedia data, a bi-directional collaborative framework for a content distribution network and a peer-to-peer network to benefit from one another, a peer-to-peer caching technique, a periodic broadcast scheme that offers low response time and is capable of serving a large number of requests, a generic periodic broadcast server capable of implementing many of the existing periodic broadcast schemes in the literature with few changes in coding, Quality of Service (QoS) core-based routing using a set of core nodes to deliver multimedia data from multiple senders to multiple receivers, taking the desired QoS into account, and techniques to detect malicious peer nodes in peer-to-peer streaming. Dr. Tavanapong has published a number of conference and journal publications on these works. Some of these research works have been partially funded by the National Science Foundation.

Representative Publications:

Tran, M. and Tavanapong, W.On the Design, Analysis, and Implementation of a Generalized Periodic Broadcast Server. To appear in IEEE Transactions on Broadcasting.

Sheu, S., Tavanapong, W. and Hua K. A. (2006). A Scalable Cost-effective Video Broadcasting System for On-demand Video Services. Multimedia Tools and Applications, 28(3): 321-345.

Shetty, S., Galdames, P.,Tavanapong, W. and Cai Y.(2006). Detecting Malicious Peers in Overlay Multicast Streaming. To appear in Proc. of IEEE Conf. on Local Area Networks (LCN), Florida.

Cao, Y., Liu, D., Tavanapong, W., Wong, J., Oh, J. and de Groen P. C. (2006). Automatic Classification of Images with Appendiceal Orifice in Colonoscopy Videos. Proc. of IEEE Engineering in Medicine and Biology Conference. New York City, New York.

Tran M. and Tavanapong, W. (2005). Peer-assisted Content Distribution Networks. Proc. of IEEE Conf. on Local Computer Networks (LCN), pages 123-131, Sydney, Australia.

Hwang, S.,Oh, J., Lee, J.,de Groen, P. C., Cao, Y., Tavanapong, W., Liu, D.and. Wong. J.(2005). Automatic Measurement of Quality Metrics for Colonoscopy Videos. Proc. of ACM Multimedia 2005, pages 912-921, Singapore.

Y. Cao, D. Li, W. Tavanapong, J. Wong, J. Oh, and P. C. de Groen. Parsing and Browsing Tools for Colonoscopy Videos. Proc. of ACM Multimedia 2004, pages 844-851, New York, NY, USA.

Tavanapong, W. and Zhou, J. (2004). Shot Clustering Techniques for Story Browsing. IEEE Transactions on Multimedia, 6(4): 517-527.

Cao, Y., Li, D., Tavanapong, W., Wong, J., Oh, J. and de Groen, P. C. (2004). A Visual Model Approach for Parsing Colonoscopy Videos. Proc. of Int'l Conf. on Image and Video Retrieval (LNCS 3115), pages 160-169, Dublin, Ireland.



JIN TIAN, Assistant Professor of Computer Science

Ph.D. 2002, Computer Science, University of California, Los Angeles

Major Interests:

Artificial Intelligence: Bayesian networks, probabilistic reasoning, causal reasoning and learning.

Current Research:

The long term goal of Dr. Tian's research is to provide theoretical foundations that will facilitate building intelligent systems that can learn about and reason with causes and effects. Dr. Tian's recent research is focused on causal reasoning and learning in the framework of causal Bayesian networks. Some topics that Dr. Tian has been working on include: learning causal structures from data, inferring causal effects from a combination of data and qualitative causal assumptions, identifying linear causal relationships in structural equation models.

Representative Publications:

Kang, C. and Tian, J. (2006). Inequality Constraints in Causal Models with Hidden Variables. Conference on Uncertainty in Artificial Intelligence (UAI), Cambridge, Massachusetts, AUAI Press. pp. 233-240.

Tian, J., Kang, C., and Pearl, J. (2006). A Characterization of Interventional Distributions in Semi-Markovian Causal Models. Proceedings of the National Conference on Artificial Intelligence (AAAI), Boston, Massachusetts. AAAI Press, pp. 1239-1244.

Tian, J. (2005). Identifying Direct Causal Effects in Linear Models. the National Conference on Artificial Intelligence (AAAI), Pittsburgh, Pennsylvania, AAAI Press. pp. 346-352.

Tian, J. (2004). Identifying Linear Causal Effects. Proceedings of the National Conference on Artificial Intelligence (AAAI), San Jose, California, AAAI Press. pp. 104-110, 2004.

Tian, J. (2004). Identifying Conditional Causal Effects. Proceedings of the Conference on Uncertainty in Artificial Intelligence (UAI), Banff, Canada. AUAI Press. pp. 561-568.

Tian, J. and Pearl, J.(2002). A general identification condition for causal effects, in Proceedings of the National Conference on Artificial Intelligence (AAAI).

Tian, J. and Pearl, J.(2002)., On the Testable Implications of Causal Models with Hidden Variables, in Proceedings of the Conference on Uncertainty in Artificial Intelligence (UAI).

Tian, J. and Pearl, J.(2001)., Causal Discovery from Changes, in Proceedings of the Conference on Uncertainty in Artificial Intelligence (UAI).

Tian, J. and Pearl, J.(2000)., Probabilities of causation: Bounds and identification, in Annals of Mathematics and Artificial Intelligence 28: 287-313.

Tian, J. (2000). A branch-and-bound algorithm for MDL learning Bayesian networks, in Proceedings of the Conference on Uncertainty in Artificial Intelligence (UAI).

 


JOHNNY S. K. WONG, Professor of Computer Science

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

Research Interests:

Operating Systems, Distributed Systems, Communication Networks, Multimedia and Medical Information Systems, Intelligent Multi-Agents Systems, Data Mining, Intrusion Detection and Response, Wireless Ad-hoc Networks and Peer-to-Peer Systems.

Current Research:

Dr. Wong's current research interests include design and implementation issues in operating systems, distributed systems, multimedia communications and medical information systems. Current activities focus on systems and network security, intrusion detections and response using intelligent mobile agents, endoscopic medical information systems (EMIS).

Representative Publications:

Cai, Y., Natarajan, A.and Wong, J. (2007). On Scheduling of Peer-to-Peer Video Services, IEEE Journal on Selected Areas in Communications, Vol. 25 (1), pp. 140-145.

Zhang, M., Wong, J., Tavanapong, W., Oh, J. and de Groen. P.C. (2006). Design and Analysis of a Media Uploading System. Journal of Multimedia Tools and Applications, Accepted.

Stakhnova, N., Basu, S., Lutz, R. and Wong, J. (2006).Automatic caching of behavioral patterns for efficient run-time monitoring. The 2nd IEEE International Symposium on Dependable, Autonomic and Secure Computing (DASC'06), Indianapolis, USA, IEEE. pp. 333-340.

Hwang, S., Oh, J., Lee, J., Tavanapong, W., de Groen, P.C. and Wong J.Informative Frame Classification for Endoscopy Video Medical Image Analysis. Medical Image Analysis Journal, In press.

Yang, C., Zhou, J., Zhang, W. and Wong, J. (2006). Pairwise Key Establishment for Large-Scale Sensor Networks: from Identifier-based to Location-Based. Infoscale 2006: First International Conference on Scalable Information Systems, Hong Kong, ACM. pp. 1-4.

Stakhanova, N., Basu, S. and Wong, J. (2006). A Taxonomy of Intrusion Response Systems. The International Journal of Information and Computer Security, Inderscience, Accepted.

Babbitt, R., Wong, J., Chang, C. and Mitra, S. (2006). Privacy Management In Smart Homes: Design And Analysis. International Conference on Aging, Disability and Independence, ST. Petersburg, Florida. pp. 255.

Putthividhya, W., Tavanapong W. and Wong J. (2006). Core-based Routing with QoS Support for Distributed Interactive Multimedia Applications. International Journal of Computer Science and Network Security. Vol. 6. No. 1B. pp. 47-57.

Wang, Y., Behera, S., Wong, J., Helmer, G., Honavar, V., Miller, L., Slagell, M. and Lutz, R.(2006). Towards the automatic generation of mobile agents for distributed intrusion detection systems. Journal of Systems & Software, Elsevier. Vol. 79. No. 1. pp. 1-14.

Babbitt, R., Lu, D., Chang. C. and Wong, J. (2005). Requirements Engineering for Smart Homes to Support Successful Aging, Disability and Independence. Annals of The European Academy of Sciences, EAS Publishing House. pp. 107-127.

 


WENSHENG ZHANG, Assistant Professor of Computer Science

Ph.D. 2005, Computer Science, The Pennsylvania State University

Major Interests:

Computer networks, network security, and applied cryptography

Current Research:

Dr. Zhang's current research is to explore the technologies and theories for designing more efficient and secure wireless networks (with a focus on wireless sensor networks). To purse this goal, he is working in three aspects: (1) designing new or improving existing protocols for wireless networks to enable more applications with higher efficiency and reliability; (ii) investigating new cryptographic and non-cryptographic methodologies, and applying them in designing more efficient strategies and protocols to protect wireless networks as well as the applications lying on top of them; (3) identifying the limitations of existing theories and techniques in specifying and verifying wireless network protocols, and developing exploring new approaches.

Representative Publications:

Zhang, W., Cao, G. and La Porta, T. Dynamic Proxy Tree-Based Data dissemination Scheme for Wireless Sensor Networks.ACM/Springer Wireless Networks, to appear.

Zhang, W., Song, H., Zhu, S. and Cao, G. (2005). Least Privilege and Privilege Deprivation: Towards Tolerating Mobile Sink Compromises in Wireless Sensor Networks, ACM International Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC).

Zhang, W. and Cao, G. (2005).Defend Against Cache Consistency Attacks in Wireless Ad Hoc Networks, Annual International Conference on Mobile and Ubiquitous Systems: Networks and Services (Mobiquitous).

Zhang, W. and Cao, G. (2005).Group Rekeying for Filtering False Data in Sensor Networks: A Predistribution and Local Collaboration-Based Approach,IEEE Conference on Communications (INFOCOM).

Wang, G., Cao, G., La Porta, T. and Zhang, W. (2005). Sensor Relocation in Mobile Sensor Networks, IEEE Conference on Communications (INFOCOM).

Zhang, W. and Cao, G. (2004). DCTC: Dynamic Convoy Tree-Based Collaboration for Target Tracking in Sensor Networks,IEEE Transactions on Wireless Communication, Vol. 3, No. 5, pp. 1689-1701.

 

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