My research has been in the area of applied probability models and stochastic processes, with special emphasis on queueing theory, reliability theory, and stochastic scheduling.
One part of my research focuses on polling models in queueing theory. Polling models are used to represent systems of multiple service facilities that are attended by a single server that travels from queue to queue in some prescribed manner. These models have numerous applications (flexible manufacturing, materials handling, machine maintenance and repair, computer networks, traffic control, telephone switching systems, etc.) and, in general, they are very complicated. The aim of my research is to develop methods that simplify the analysis of polling models. The idea behind our methods is to decompose these extremely complicated models into simpler independent subproblems.
Another part of my research is the development of stochastic models of new-product diffusion. Diffusion models provide useful insight into the purchase timing of new products by consumers. The general thrust of this research is to extend the widely-used deterministic Bass model to stochastic settings. Such extensions make possible the development of a rigorous sampling theory, which serves as a proper foundation for empirical research on new-product demands. Improved modeling also allows us to better understand the underlying forces (price and advertising, in particular) that influence the sales trajectory of new products.
Teaching Material Developed
Developed over 200 pages of online course material for OPRE 6201-Introduction to Operations Research (Summer 2000; GMBA Program).
Chairman of Ph.D. Dissertation Committee for Hong Yin at The University of Texas at Dallas, August 2005. Thesis Title: "Optimization Models for Business-Process Outsourcing and for Short-Life-Cycle-Product Planning."
Chairman of Ph.D. Dissertation Committee for Chenping Pai at The University of Texas at Dallas, Spring 1996. Thesis Title: "Sample-Average Analysis of M/G/l- Type Retrial Queueing Systems with Finite Capacity." Placement: US One Communications.
Chairman of Ph.D. Dissertation Committee for Madhusudhan Vudali at The University of Texas at Dallas, December 1996. Thesis Title: "Performance Analysis of Two Classes ofPolling Models." Placement: Decision Focus, Inc.
Chairman of Ph.D. Dissertation Committee for Jingwen Li at The University of Texas at Dallas, December 1989. Thesis Title: "Sample-Average Analyses of Some Generalizations of the MIGII Queue." Placement: National University of Singapore.
Chairman of Ph.D. Dissertation Committee for Peng-Sheng Ku at The University of Texas at Dallas, Spring 1984. Thesis Title: "Optimal Scheduling Policies for Some Stochastic Flowshop, Jobshop, and Openshop Problems." Placement: AT&T Bell Laboratories.
Member of Ph.D. Dissertation Committees at UTD: Shailesh Ashok Shirali (OR), December 1980; Chung-Ting Shueh (OR), December 1981; Fan-Tsong Tseng (OR),December 1983; Santosh R. Kabadi (OR), Fall 1984; Yu-Yang Lin (OR), Fall 1985; Dipak Jain (Marketing), Fall 1986; Jiann-Min Yang (OR), August 1987; Zhongjun Hao (OR), August 1988; S. Lakshmi Narasimhan (OR), August 1988; Sambhavi Lakshminarayan (OR), August 1989; Swaminathan Sridhar (OR), August 1990; Ramaswamy Venkatesh (Computer Science), August 1990; Kala Seal (MIS), August 1990; Joyendu Bhadury (OR), August 1991; Robert E. Best (OR), August 1992; Perinkul R. Narayanan (OR), August 1992; Amit K. Mukhopadhyay (OR), August 1992; Ching-Chin Chern (OR), May 1995; Jennifer Huang (OR), May 1995; Zishun Wang (OR), August 1995; Rajesh Jagannathan (OR), May 1998; John Rudin (OR), May 2001; Xiaohang Yue (OM), August 2002; Amir Parssian (IS), August 2002; Neil Geismar (OM), August 2003; Xianghua Gan (OM), May 2005; Taesun Kim (Marketing), December 2005; Qi Feng (OM), May 2006; Srikant Kuppa (Computer Science), May 2006; Cuneyd C. Kaya (IS), October 2006.
Winner of Halliburton Award for Teaching Excellence at UTD (School of Management), 1990.
Operations Research (undergraduate level, UTD) Production Management (undergraduate level, UTD) Business Statistics (undergraduate level, CSU) Business Mathematics (Master's level, CSU) Introduction to Operations Research (Master's level, UTD) Quantitative Introduction to Risk and Uncertainty in Business (Master's level, UTD) Systems Simulation (Master's level, UTD)
Probability and Stochastic Processes (Ph.D. level, UTD) Stochastic Models in Operations Research (Ph.D. level, UTD) Polling Models Seminar (Ph.D. level, UTD) Queueing Theory (Ph.D. level, UTD) Reliability Theory (Ph.D. level, UTD) Simulation Seminar (Ph.D. level, UTD) Stochastic Dynamic Programming (Ph.D. level, UTD) Stochastic Scheduling Seminar (Ph.D. level, UTD)
Service at UTD Served as Area Coordinator of Operations Research, three terms in the past 26 years.Served on the following university-wide committees: Committee on Qualifications (four two-year terms); Committee on Student Scholarships (two years); Committee on Educational Policy (one term); Faculty Senate (since 2003); the University Research Integrity Committee (since 2001).
Served on numerous School o f Management standing and ad hoc committees.
Reviewed statistics textbook for Prindle, Weber and Schmidt (1979). Served numerous times as referee for:
Advances in Applied Probability Annuals ofOperations Research Army Research Office Asia-Pacific Journal o f Operational Research European Journal ofOperational Research IEEE Transactions on Information Theory lIE Transactions
Journal of Applied Mathematics and Stochastic Analysis Journal o fApplied Probability Journal o fMathematical Analysis and Applications Journal ofScheduling
Mathematics of Operations Research
National Science Foundation Naval Research Logistics (formerly Naval Research Logistics Quarterly) Operations Research Opsearch Optimal Control Applications and Methods Probability in the Engineering and Informational Sciences Queueing Systems, Theory and Applications
Member of INFORMS (Institute for Operations Research and the Management Sciences).
Member of INFORMS Applied Probability Society (APS).