Principal Organizer, International Workshop Series on Advanced Topics in Risk and Reliability Analysis.

Technical Program Chairman, International Conference on Probabilistic Safety Assessment and Management, PSAM-4, New York, Sept. 1998.

Co-organizer, International Workshop on Reliability Growth Modeling, Maryland, October 26-28, 1994.

Co-organizer, International Workshop on Human Reliability, Stockholm, Sweden, August 22-25, 1994.

Co-organizer, International Workshop on Model Uncertainty, Annapolis, MD, Oct 19-21, 1993.

Co-organizer, NATO Advanced Research Workshop, Reliability of Dynamic Systems, Turkey, August 1993.

Chairman, 4th International Computer Security Risk Modeling Workshop, University of Maryland, College Park, August 6-8 1991.

Technical Area Coordinator, International Conference on Probabilistic Safety Assessment and Management, PSAM-III, Crete, Greece. June 1996.

Member, Technical Program Committee, International Conference on Probabilistic Safety Assessment and Management, PSAM -I, Beverly Hills, Ca, Feb. 3-7 1991.

Member, Organizing and Technical Program Committees, International Conference on Probabilistic Safety Assessment and Management, PSAM -II, San Diego, March 1994.

Member, Technical Program Committee, and National Organizing Committee, First International Symposium on Uncertainty Modeling and Analysis, University of Maryland, College Park, Dec. 3-5, 1990.

Member, Technical Program Committee, International Conference on Probabilistic Safety Assessment, PSA'95, Korea 1995.

Member, Technical Program Committee, International Conference, International Conference on Probabilistic Safety Assessment, PSA'96, Park City, Utah, 1996.

Member, Technical Program Committee, International Topical Meeting on Computer-Based Human Support Systems: Technology, Methods, and Future, Philadelphia, June 1995.

Co-organizer, Simulation Multi-Conference of the Society for Computer Simulation, Virginia, March 1993.

Member, Technical Program Committee, Joint Conference of the International Symposium on Uncertainty Modeling & Analysis (ISUMA), and the North American Fuzzy Information Processing Society (NAFIPS), College Park, Maryland, 1995.