Former group member (MS, 1992; Ph.D., 1996).

### Publications with the Performability Engineering Research Group

Performability Modeling with *UltraSAN*.

J. Couvillion, R. Freire, R. Johnson, W. D. Obal II, M. A. Qureshi, M. Rai, W. H. Sanders, and J. E. Tvedt. (91C01)*IEEE Software*, vol. 8, no. 5, Sept. 1991, pp. 69-80. [IEEE Xplore entry]*Overview paper on *UltraSAN. *Provides a basic introduction to the package.*

Performability Modeling with *UltraSAN*.

J. Couvillion, R. Freire, R. Johnson, W. D. Obal II, M. A. Qureshi, M. Rai, W. H. Sanders, and J. E. Tvedt. (91C02, available in hard copy)*Proceedings of the 4th International Workshop on Petri Nets and Performance Models*, Melbourne, Australia, December 2-5, 1991, pp. 290-299. [IEEE Xplore entry]*Conference version of above paper.*

Reward Model Solution Methods with Impulse and Rate Rewards: An Algorithm and Numerical Results.

M. A. Qureshi. (92Q01)

Master’s Thesis, University of Arizona, 1992.

Reward Model Solution Methods with Impulse and Rate Rewards: An Algorithm and Numerical Results.

W. H. Sanders and M. A. Qureshi.*2nd ORSA Telecommunications Conference*, Boca Raton, FL, Mar. 1992.

Reward Model Solution Methods with Impulse and Rate Rewards: An Algorithm and Numerical Results.

M. A. Qureshi and W. H. Sanders. (94QUR01)*Performance Evaluation*, vol. 20, 1994, pp. 413-436.*Presents a method to compute performability distribution of reward models with impulse and rate rewards. *[published version and erratum from Elsevier]

The Effect of Workload on the Performance and Availability of Voting Algorithms.

M. A. Qureshi and W. H. Sanders. (95QUR01)*Proceedings of the International Workshop on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS ’95)*, Durham, NC, January 18-20, 1995, pp. 217-224. [IEEE Xplore entry]*Modeling study of voting algorithms.*

*UltraSAN* Version 3: Architecture, Features, and Implementation.

W. H. Sanders, W. D. Obal II, M. A. Qureshi, and F. K. Widjanarko. (95S02)*Proceedings of the AIAA Computing in Aerospace 10 Conference*, San Antonio, TX, March 28-30, 1995, pp. 327-338.*Discussion of the features and architecture of *UltraSAN *Version 3.0, with an example.*

*UltraSAN* Version 3 Overview.

D. D. Deavours, W. D. Obal II, M. A. Qureshi, W. H. Sanders, and A. P. A. van Moorsel. (95DEA01)*Proceedings of the Sixth International Workshop on Petri Nets and Performance Models*, Durham, NC, October 3-6, 1995, pp. 216-217. [IEEE Xplore entry]*A two-page overview of *UltraSAN *Version 3.0*.

Algorithms for the Generation of State-Level Representations of Stochastic Activity Networks with General Reward Structures.

M. A. Qureshi, W. H. Sanders, A. P. A. van Moorsel, and R. German. (95Q02)*Proceedings of the Sixth International Workshop on Petri Nets and Performance Models*, Durham, NC, October 3-6, 1995, pp. 180-190. [IEEE Xplore entry]*This paper discusses the generation of the stochastic process underlying a SAN, including the algorithm for the well-specified check. Furthermore, a general reward structure is introduced that can represent all reward variables defined on the marking behavior of a SAN.*

The *UltraSAN* Modeling Environment.

W. H. Sanders, W. D. Obal II, M. A. Qureshi, and F. K. Widjanarko. (95S01)*Performance Evaluation*, vol. 24, no. 1, October-November 1995, pp. 89-115.*Overview of *UltraSAN *Version 3.0*.

The Effect of Workload on the Performance and Availability of Voting Algorithms.

M. A. Qureshi and W. H. Sanders. (95QUR03)*Microelectronics and Reliability*, Special Issue on Performance Modeling and Reliability Analysis, June 1996, vol. 36, no. 6, pp. 757-774.

Expected Impulse Rewards in Markov Regenerative Stochastic Petri Nets.

R. German, A. P. A. van Moorsel, M. A. Qureshi, and W. H. Sanders. (95GER01)*Application and Theory of Petri Nets, Proceedings of the 17th International Conference*, Osaka, Japan, June 24-28, 1996, pp. 172-191 (ed. J. Billington and W. Reisig), *Lecture Notes in Computer Science*, Vol. 1091, Springer-Verlag, 1996.*Computes reward measures for Petri nets with general distributions. Furthermore, the method of supplementary variables is enhanced to derive transient solutions of models with general distributions.*

A New Methodology for Calculating Distributions of Reward Accumulated During a Finite Interval.

M. A. Qureshi and W. H. Sanders. (95QUR04)*Proceedings of the 26th International Symposium on Fault-Tolerant Computing*, Sendai, Japan, June 1996, pp. 116-125. [IEEE Xplore entry]*This paper presents a new method to compute the distribution of reward accumulated during a finite interval in a Markov reward model. It does this by computing probabilities of particular paths in a uniformized version of the process, and computing the conditional distribution of reward accumulated, given a path.*

Algorithms for the Generation of State-Level Representations of Stochastic Activity Networks with General Reward Structures.

M. A. Qureshi, W. H. Sanders, A. P. A. van Moorsel, and R. German. (95QUR05)*IEEE Transactions on Software Engineering*, vol. 22, no. 9, September 1996, pp. 603-614. [IEEE Xplore entry]*Same description as for conference version, above.*

Overview of *UltraSAN*.

W. D. Obal II, M. A. Qureshi, D. D. Deavours, and W. H. Sanders. (96OBA01)*Proc. IEEE Int. Performance and Dependability Symposium*, Urbana, IL, Sept. 4-6, 1996. [IEEE Xplore entry]

Construction and Solution of Markov Reward Models.

M. A. Qureshi. (96QUR02)

Doctoral Dissertation, University of Arizona, 1996.

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