Haiping Xu , Ph.D.

Computer and Information Science Department
University of Massachusetts Dartmouth

Mailing Address:
285 Old Westport Rd., North Dartmouth, MA 02747

Office: 508-910-6427 Fax: 508-999-9144
Email: hxu@umassd.edu

EDUCATION

Ph.D. in Computer Science, University of Illinois at Chicago, May 2003
Dissertation: A Model-Based Approach for Development of Multi-Agent Software Systems
Cumulative GPA: 5.0/5.0. (Ph.D. Thesis)

M.S. in Computer Science, Wright State University, Ohio, June 1998
Project: Task Partitioning and Allocation on Supercomputers and Network of Workstations
Cumulative GPA: 3.9/4.0.

M.S. in Computer Engineering, Zhejiang University, China, March 1992
Thesis: Development of Intelligent Chinese Tutoring System
Cumulative GPA: 3.7/4.0.

B.S. in Electrical Engineering, Zhejiang University, China, July 1989
Thesis: Computer-Aided Design of Quadratic Regulator
Cumulative GPA: 3.8/4.0.

WORK EXPERIENCE

September 2003 - Present
Associate Professor, Computer and Information Science Department, University of Massachusetts Dartmouth
Researched on distributed software engineering, model-based software development, including formal specification, design analysis, and model checking.

September 2004 - Present
Co-Director, Concurrent Software Engineering Laboratory, University of Massachusetts Dartmouth

August 1998 - May 2003
Research Assistant, Concurrent Software Systems Laboratory, University of Illinois at Chicago
Researched on distributed software engineering, model-based software development, including formal specification, design analysis, and model checking.

September 1996 - June 1998
Research Assistant, Parallel Computing Laboratory, Wright State University
Developed task partitioning and allocation software packages on supercomputers and network of workstations.

May 1996 - August 1996
Research Scholar, Intelligent Systems Laboratory, Nanyang Technological University (Singapore)
Researched on intelligent multimedia tutoring systems for software engineering education.

August 1995 - May 1996
Software Engineer, Hewlett-Packard Company (China)
Worked with a team that provided end-to-end network and software solutions for China Construction Bank.

March 1992 - July 1995
Software Engineer, Shen-Yan Systems Technology Inc. (China)
Developed various management information systems using C/C++, Informix, and Oracle.

PROJECTS

Click Here for a List of My Recent Funding and Grant Activities

CS Web Editor (2002)
An Interface for updating the content of Computer Science Department web pages at the University of Illinois at Chicago. Developed using HTML, JavaScript, PHP, and MySQL on Apache web server.

ADK 1.0¹ (Agent Development Kit) (2001)
A full class library that supports development of application-specific agents, such as selling and buying agents in electronic commerce. Developed using Java and Sun Jini.

Chat Room Application (2000)
A comprehensive chat room application that can be run as a console program, a Win32 application, or an applet in most web browsers. Developed using Visual C++, Java, Servlet, JavaServer Pages (JSP), and Java Applets.

Java Compiler (1999)
Lexical analyzer, parser, and converter of Java code into assembly code. Written in Java.

PWD (Profile driven Weighted Decomposition) (1998)
A software package that facilitates task partitioning and allocation on network of workstations. Developed using C++ and LAM/MPI.

AgentDtk (Agent-based Design tool kit) (1998)
A mobile agent system that provides an interface for computer-aided design and remote information retrieval. Written in Tcl/Tk.

MediaBoard (1997)
A whiteboard application for Internet meeting. It provides a shared drawing board and facilitates message exchanging among users. Developed using C++, Java, and CORBA.

IMTS (Intelligent Multimedia Tutoring System) (1996)
A tutoring system for laboratory support in software engineering education. Developed using C++ and Motif.

BDMIS (Beijing Dannong Management Information System) (1995)
A comprehensive management information system, including inventory, payroll and personnel, for Beijing Dannong Company. Developed using C++ and Oracle.

COMPUTER SKILLS

Languages: C/C++, Java, Tcl/Tk, Perl, PHP, Smalltalk, FORTRAN, LISP, UML
Network and Internet Technology: TCP/IP, Client-Server architecture, CORBA,
SOAP, Jini, RMI, HTML/DHTML, XML, CGI scripts, Java Servlets, JSP, Microsoft .NET
Databases: Oracle (Developer/2000), MySQL, Informix, SQL Server, MS Access,
JDBC, ODBC
Operating Systems: Windows 98/2000/XP, UNIX (Solaris, Digital Unix, HP-UX), Linux

Fei Dong, Sol M. Shatz, Haiping Xu, and Dibyen Majumdar, "Price Comparison: A Reliable Approach to Identifying Shill Bidding in Online Auctions?," Electronic Commerce Research and Applications (ECRA), Vol. 11, No. 2, March-April 2012, pp. 171-179. (PDF File ~360K)

Ryan Robidoux, Haiping Xu, Liudong Xing, and MengChu Zhou, "Automated Modeling of Dynamic Reliability Block Diagrams Using Colored Petri Nets," IEEE Transactions on Systems, Man, and Cybernetics, Part A: Systems and Humans (SMC-A), Vol. 40, No. 2, March 2010, pp. 337-351. (PDF File ~932K)

Fei Dong, Sol M. Shatz, and Haiping Xu, "Reasoning Under Uncertainty for Shill Detection in Online Auctions Using Dempster-Shafer Theory," International Journal of Software Engineering and Knowledge Engineering (IJSEKE), Vol. 20, No. 7, November 2010, pp. 943-973. (PDF File ~463K)

Haiping Xu, Mihir Ayachit, and Abhinay Reddyreddy, "Formal Modeling and Analysis of XML Firewall for Service-Oriented Systems," International Journal of Security and Networks (IJSN), Vol. 3, No. 3, 2008, pp. 147-160. (PDF File ~1.9M)

Haiping Xu, Liudong Xing, and Ryan Robidoux, "DRBD: Dynamic Reliability Block Diagrams for System Reliability Modeling," International Journal of Computers and Applications (IJCA), Vol. 31, No. 2, 2009, pp. 132-141. (PDF File ~945K)

Fei Dong, Sol M. Shatz, and Haiping Xu, "Combating Online In-Auction Fraud: Clues, Techniques and Challenges," Computer Science Review (CSR), Vol. 3, No. 4, November 2009, pp. 245-258. (PDF File ~1.8M)

Zhenhua Yu,Yuanli Cai, and Haiping Xu, "Petri Nets Semantics of π-calculus," Frontiers of Electrical and Electronic Engineering in China (FEEEC) , September 2008, Vol. 3, No. 3, pp. 290-294 . (PDF File ~282K)

Haiping Xu and Yi-Tsung Cheng, "Model Checking Bidding Behaviors in Internet Concurrent Auctions," International Journal of Computer Systems Science & Engineering (IJCSSE), July 2007, Vol. 22, No. 4, pp. 179-191. (PDF File ~1.2M)

Zhenhua Yu,Yuanli Cai, and Haiping Xu, "Modeling and Analyzing Multi-Agent Systems Based on π-net," Systems Engineering - Theory & Practice (SETP), July 2007, Vol. 27, No. 7, pp. 77-84 (in Chinese). (PDF File ~630K)

Zhenhua Yu,Yuanli Cai, and Haiping Xu, "On Petri Nets Semantics for π-calculus,"Journal of Control and Decision (JCD), August 2007, Vol. 22, No. 8, pp. 864-868 (in Chinese). (PDF File ~430K)

Haiping Xu, Xiaoqin Zhang, and Rinkesh J. Patel, "Developing Role-Based Open Multi-Agent Software Systems," International Journal of Computational Intelligence Theory and Practice (IJCITP), June 2007, Vol. 2, No. 1, pp. 39-56. (PDF File ~845K)

Xiaoqin Zhang, Haiping Xu, and Bhavesh Shrestha, "An Integrated Role-Based Approach for Modeling, Designing and Implementing Multi-Agent Systems," Journal of the Brazilian Computer Society (JBCS), Special Issue on Software Engineering for Multi-Agent Systems, July 2007, Vol. 13, No. 1, pp. 45-60. (PDF File ~976K)

Zhenhua Yu,Yuanli Cai, and Haiping Xu, "On Modeling Approach for Dynamic Software Architecture," Journal of Xi'an Jiaotong University (JXJU), February 2007, Vol. 41, No. 2, pp. 167-171 (in Chinese). (PDF File ~770K)

Haiping Xu, Zhiguo Zhang, and Sol M. Shatz, "A Security Based Model for Mobile Agent Software Systems," International Journal of Software Engineering and Knowledge Engineering (IJSEKE), August 2005, Vol. 15, No. 4, pp. 719-746. (PDF File ~663K)

Haiping Xu and Sol M. Shatz, "ADK: An Agent Development Kit Based on a Formal Model for Multi-Agent Systems," Journal of Automated Software Engineering (AUSE), Vol. 10, No. 4, October 2003, pp. 337-365. (PDF File ~700K)

Haiping Xu and Sol M. Shatz, "A Framework for Model-Based Design of Agent-Oriented Software²," IEEE Transactions on Software Engineering (IEEE TSE), January 2003, Vol. 29, No. 1, pp. 15-30. (PDF File ~3.5M)

Ravi K. Gedela, Sol M. Shatz, and Haiping Xu, "Compositional Petri Net Models of Advanced Tasking in Ada-95," Computer Languages, July 1999, Vol.25, No.2, pp.55-87. (download from ScieceDirect) (PDF File ~850K)

Ravi K. Gedela, Sol M. Shatz, and Haiping Xu, "Formal Modeling of Synchronization Methods for Concurrent Objects in Ada 95," ACM SIGAda Ada Letters , 1999, Volume XIX, Issue 3, pp.211-220. Also appears in [GSX99c]

Haiping Xu, Xiaogang Ruan, Zengwu Chen, Shangxu Hu, and Haibo Ren, "ICTS: Hypertext and Multi-Knowledge Source Based Intelligent Chinese Tutoring System," Journal of Chinese Information Processing, 1992, Vol. 6, No. 2, pp.8-16 (in Chinese).

Qiuping Hu, Haiping Xu, Yurun Zhang, and Chunhui Zhou, "Software Design of an Expert Control System in Vacuum Distillation," Control and Instruments in Chemical Industry, 1992, Vol. 19, No. 4, pp.25-29 (in Chinese).

Haiping Xu, "Software Design of Microcomputer Based Electronic Scalers," Process Automation Instrumentation, 1991, Vol. 12, No. 10, pp. 13-16 (in Chinese). (PDF File ~ 4.5M)

Conference Papers

Xiaoqin Zhang and Haiping Xu, "Towards Automated Development of Multi-Agent Systems Using RADE," In Proceedings of the 2006 International Conference on Artificial Intelligence (ICAI'06), June 26-29, 2006, Las Vegas, Nevada, USA.

Yi-Tsung Cheng and Haiping Xu, "A Formal Approach to Detecting Shilling Behaviors in Concurrent Online Auctions," In Proceedings of the 8th International Conference on Enterprise Information Systems (ICEIS 2006), May 23-27, 2006, Paphos, Cyprus. pp. 375-381.

Haiping Xu and Xiaoqin Zhang, "A Methodology for Role-Based Modeling of Open Multi-Agent Software Systems," In Proceedings of the 7th International Conference on Enterprise Information Systems (ICEIS 2005), May 24-28, 2005, Miami, Florida, USA., pp. 246-253. (Presentation)

Haiping Xu and Sol M. Shatz, "A Framework for Modeling Agent-Oriented Software²," In Proceedings of the IEEE 21st International Conference on Distributed Computing Systems (ICDCS-21), April 16-19, 2001, Phoenix, Arizona, USA, pp. 57-64. (Presentation)

Haiping Xu and Sol M. Shatz, "An Agent-Based Petri Net Model with Application to Seller/Buyer Design in Electronic Commerce²," In Proceedings of the IEEE 5th International Symposium on Autonomous Decentralized Systems (ISADS 2001), March 26-28, 2001, Dallas, Texas, USA, pp.11-18. (Presentation)

Haiping Xu and Sol M. Shatz, "Extending G-Nets to Support Inheritance Modeling in Concurrent Object-Oriented Design²," In Proceedings of the IEEE International Conference on Systems, Man, and Cybernetics (SMC 2000), October 8-11, 2000, Nashville, Tennessee, USA, pp. 3128-3133. (Presentation)

Ravi K. Gedela, Sol M. Shatz, and Haiping Xu, "Formal Modeling of Synchronization Methods for Concurrent Objects in Ada 95," In Proceedings of the ACM Annual International Conference on Ada (SIGAda'99), October 17-21, 1999, Redondo Beach, CA, USA, pp. 211-220. (Presentation)

Kai Warendorf, Haiping Xu, and Antoon Verhoeven, "Case-Based Instructional Planning for Learning in a Context," In Proceedings of the Joint 1997 Pacific Asian Conference on Expert Systems and Singapore International Conference on Intelligent Systems (PACES/SPICIS 97), February 24-27, 1997, Singapore, pp. 354-360.

Xiaogang Ruan, Shangxu Hu, Zengwu Chen, and Haiping Xu, "The Presentation and Inference of Chinese Language Knowledge," In Proceedings of the International Conference on "Information & System", A.M.S.E., October 1991, Hangzhou, China.

Haiping Xu, Zengwu Chen, and Shangxu Hu, "Design and Implementation Techniques for an Intelligent Chinese Tutoring System," In Proceedings of the Second National Conference on Computer Application, October 1991, Beijing, China, pp. 988-991 (in Chinese).

Technical Reports

Haiping Xu and Sol M. Shatz, "Model-Based Development of Intelligent Communicating Agents for Multi-Agent Systems," Computer Science Department, The University of Illinois at Chicago, August 2002.

Haiping Xu and Sol M. Shatz, "A Design Model for Intelligent Mobile Agent Software Systems," Computer Science Department, The University of Illinois at Chicago, May 2002.

Haiping Xu, "Formal Methods in Agent-Oriented Software Engineering," Lecture on CS542: Distributed Software Engineering, Computer Science Department, The University of Illinois at Chicago, October 2001. (Presentation)

Haiping Xu, "Mobile Agents," Ph.D. Student Seminar, Computer Science Department, The University of Illinois at Chicago, June 2001. (Presentation)

Haiping Xu and Sol M. Shatz, "Formal Methods in Agent-Oriented Design and Analysis," Proposal for Book Chapters in Intelligent Agent Software Engineering, EECS Department, The University of Illinois at Chicago, March 2001. (Chapter-Proposal.ps.gz)

Haiping Xu, "From Object to Agent: An Approach to Using Formal Methods in Software Design and Analysis," Ph.D. Thesis Proposal, EECS Department, The University of Illinois at Chicago, Feb. 2001. (Thesis-Proposal.ps.gz) (Presentation)

Haiping Xu, "Java Security Model and Bytecode Verification," Technical Report EECS-12-99, EECS Department, The University of Illinois at Chicago, December 1999.

Haiping Xu, "Modeling and Analyzing Search/Insert/Delete Problem by Petri Nets," Technical Report EECS-05-99, EECS Department, The University of Illinois at Chicago, May 1999.

Thesis & Project

Haiping Xu, "A Model-Based Approach for Development of Multi-Agent Software Systems," Ph.D. Thesis, Department of Computer Science, University of Illinois at Chicago, March 2003. Outstanding Ph.D. Thesis Award 2004, Thesis Supervisor: Dr. Sol M. Shatz. (UIC CS News)

Haiping Xu, "Task Partitioning and Allocation on Supercomputers and Network of Workstations," Master's Project, Wright State University, Dayton, OH, USA, May 1998.

Haiping Xu, "Development of Intelligent Chinese Tutoring System," Master's Thesis, Zhejiang University, Hangzhou, China, January 1992.

Haiping Xu, "Computer-Aided Design of Quadratic Regulator," Undergraduate Thesis, Zhejiang University, Hangzhou, China, July 1989.

TALKS

Haiping Xu, "Towards a Role-Based Agent Development Environment for Open Multi-Agent Software Systems," CIS Seminars, Computer and Information Science Department, University of Massachusetts Dartmouth, October 2005. (Slides ~1.5M) (PDF File ~880K)

Haiping Xu, "A Methodology for Role-Based Modeling of Multi-Agent Software Systems," The 7th International Conference on Enterprise Information Systems (ICEIS 2005), May 24-28, 2005, Miami, Florida, USA. (Slides)

Haiping Xu, "A Security Based Model for Mobile Agent Software Systems," CIS Seminars, Computer and Information Science Department, University of Massachusetts Dartmouth, April 2004. (Slides ~1.4M) (PDF File ~800K)

Haiping Xu, "A Model-Based Approach for Development of Multi-Agent Software Systems," Computer Science Colloquium, Computer Science Department, University of Massachusetts Boston, December 2003. (Slides ~3.2M ) (PDF File ~1.2M)

Haiping Xu, "A Model-Based Approach for Development of Multi-Agent Software Systems," Computer Science Colloquium, School of Electrical Engineering and Computer Science, Oregon State University, May 2003.

Haiping Xu, "A Model-Based Approach for Development of Multi-Agent Software Systems," Computer Science Colloquium, Department of Computer Science, State University of New York, Binghamton, March 2003.

Haiping Xu, "A Model-Based Approach for Development of Multi-Agent Software Systems," Computer Science Colloquium, Department of Computer Science, Iowa State University, March 2003.

Haiping Xu, "An Agent-Based Petri Net Model with Application to Seller/Buyer Design in Electronic Commerce," The Fifth International Symposium on Autonomous Decentralized Systems (ISADS 2001), March 26-28, 2001, Dallas, Texas, USA.

Haiping Xu, "Extending G-Nets to Support Inheritance Modeling in Concurrent Object-Oriented Design," The IEEE International Conference on Systems, Man, and Cybernetics (SMC 2000), October 8-11, 2000, Nashville, Tennessee, USA.

Haiping Xu, "Formal Modeling of Synchronization Methods for Concurrent Objects in Ada 95," The ACM Annual International Conference on Ada (SIGAda'99), October 17-21, 1999, Redondo Beach, CA, USA.

AWARDS AND HONORS

In United States

Marquis Who'sWho in Finance and Business, 37th Edition, 2009-2010.
Marquis Who'sWho in America, 62nd Edition, 2008, and 63rd Edition, 2009.
Who's Who Among America's Teachers, 11th Edition, 2007 (Certificate).
Outstanding PhD Thesis Award, University of Illinois at Chicago, IL, 2004 (Plaque).
University Fellowship, University of Illinois at Chicago, IL, 2001.
IEEE Computer Society Travel Grant, ISADS 2001.
NSF Student Travel Grant, SEPN Workshop 2000.
ACM SIGAda Student Travel Grant, SIGAda 1999.
Dayton Area Graduate Studies Institute (DAGSI) Scholarship, Dayton, OH, 1998.

In China

Outstanding Graduate Student Award, Zhejiang University, China, 1992.
Guang-Hua National Merit Scholarship, Hangzhou, China, 1990.
Graduate School Scholarship, Zhejiang University, Hangzhou, China, 1990.
The "Mixed Class" for talented students, Zhejiang University, Hangzhou, China, 1986.
Zhejiang University Juvenile Class for Gifted Students (aged 15 or below), China, 1985.

EXTRACURRICULAR ACTIVITIES

Senior Member of the IEEE, IEEE Computer Society (Plaque)
Senior Member of the Association of Computing Machinery (ACM)
Referee for the following journals and conferences:
Data & Knowledge Engineering Journal (DKE)
IEEE Trans. on Multimedia (IEEE TMM)
IEEE Trans. on Software Engineering (IEEE TSE)
IEEE Trans. on Parallel and Distributed Systems (IEEE TPDS)
Int'l Journal of Software Engineering & Knowledge Engineering (IJSEKE)
Int'l Conf. on Enterprise Information Systems (ICEIS 2005)
Int'l Conf. on Distributed Computing Systems (ICDCS-21) (ICDCS 2003)
Int'l Conf. on Application and Theory of Petri Nets (ICATPN 2001) (ICATPN 2002)
Int'l Symp. on Software Engineering for Parallel and Distributed Systems (PDSE)
Int'l Workshop on Software Engineering and Petri Nets (SEPN 2000)
Reporter for the Ada's Window on the World (Ada-WOW) on SIGAda'99
Student volunteer for XP/Agile Universe (Extreme Programmig and Agile Methods)
Group Coordinator for UICTennis Club.

COMMITTEE WORK

CS Undergraduate Curriculum and Program Committee, UMD (Fall 2003 ~ Present)
CS Graduate Curriculum and Program Committee, UMD (Fall 2003 ~ Present)
Faculty Senate Committees: Library Committee, UMD (Fall 2004 ~ Present)
Program Committee Member: International Conference on Enterprise
Information Systems (ICEIS 2005), Miami, Florida, USA, May 2005.
Editorial Board, The Open Software Engineering Journal (2008 ~ Present)

Click Here for a Complete List of My Committee Work

Click Here for a Complete List of Graduate Students Supervised

1. Abhinay K. Reddyreddy, Development of State-Based XML Firewall for Service-Oriented Systems, Master's Thesis, Computer and Information Science Department, University of Massachusetts Dartmouth, October 2008.
2. Ryan M. Robidoux, Automated Verification of a Computer System Reliability Model, Master's Thesis, Computer and Information Science Department, University of Massachusetts Dartmouth, July 2007.
3. Rinkesh J. Patel, Real-Time Trust Management in Agent-Based Online Auction Systems, Master's Thesis, Computer and Information Science Department, University of Massachusetts Dartmouth, February 2007.
4. Mihir M. Ayachit, A Petri Net Based XML Firewall Security Model for Web Services Invocation, Master's Thesis, Computer and Information Science Department, University of Massachusetts Dartmouth, July 2006.
5. Yi-Tsung Cheng, A Formal Approach to Detecting Shilling Behaviors in Concurrent Online Auctions, Master's Thesis, Computer and Information Science Department, University of Massachusetts Dartmouth, September 2005.
   
   

1. Ankit Goel, Evaluation of a Bayesian Network with Multi-State Nodes for Shill Verification in Online Auctions, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, August 2008.
2. Christopher K. Bates, Rule-Based Specification of Flexible Bidding Strategies in Agent-Based Online Auctions, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, January 2008.
3. Sravan K. Patti, Implementing Ontology-Based Dynamic Service Discovery in JavaSpaces, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2007.
4. Brinda V. Kommireddi, Developing a Dynamic Virtual Restaurant Using RMI, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, September 2007.
5. Abhinay K. Reddyreddy, Simulation of XML-Based Attacks for Testing the Effectiveness of XML Firewall, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, June 2007.
6. Rinkeshkumar J. Patel, A Trustworthy Agent Based Online Auction System, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2006.
7. Pratik K. Kadakia, Building a Travel Reservation System Using Web Services Composition Language, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2006.
8. Chandana Kancherla, A Service-Oriented Peer-to-Peer System for Resource Sharing, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2005 (Slides).
9. Mihir M. Ayachit, BOS: Book Ordering Section for University Faculty, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2005.
10. Tsung-Ta Tu, Online Trading and Data Mining-Based Marketing of IT Books, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2004 (Slides).
11. Minal G Pimparkar, OSPS: An Office Supplies Purchasing System Using Web Services, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2004.
12. Yi-Tsung Cheng, Information Exchange in a Multi-Agent System for Troubleshooting, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, May 2004.
13. Manuel Jose Valladares Pernas, A Multi-Agent System for Electronic Auctions, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2004 (Slides).
14. Ying-Chang Tseng, Web Based Application: Online Used Bookstore - Model Design and Implementation, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2003.
15. Kuei Chih Hsu, Web Based Application: Online Used Bookstore - View and Controller Design and Implementation, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2003.
16. Ming-Shan Hsu, Performance Comparison of Routing Protocols in Wired/Wireless Network, Master's Project, Computer and Information Science Department, University of Massachusetts Dartmouth, December 2003.