Gagan L. Choudhury

Gagan L. Choudhury

Past Awards

1997
Frederick W. Lanchester Prize: Honorable Mention
Citation:

Honorable mention in the 1997 Lanchester Prize competition is awarded to Joseph Abate, Gagan L. Choudhury, Kin K. Leung, David M. Lucantoni and Ward Whitt for a sequence of fifteen papers on numerical techniques for transform inversion, and application of those techniques to various stochastic models. The deep and scholarly work of these authors is concerned with deriving numerical performance estimates from stochastic models of computing and communication systems.

One can often derive mathematical expressions for the transforms of distributions that characterize performance of a stochastic system model, but solutions in the transform domain have long been viewed as unsatisfactory, at least partly because numerical inversion of the transforms was considered impractical. Abate et al have undertaken a sustained effort to show that notion is mistaken, although one must exploit the special character of stochastic system models if numerical inversion is to be rendered feasible. They have taken a general method of transform inversion and shown how it can be specialized and refined to treat several families of models, some of them quite large and complicated, developing routines that are fast and accurate.

Abate and his colleagues also derived a number of new and impressive transform results (that is, formulas for Laplace transforms themselves, as opposed to inversion methods), and they were often able to derive good error bounds for their inversion routines. It is not just one family of models for which fast and accurate numerical methods were developed, but a number of such families — including single-server queues with many input sources, a large class of product-form loss networks, and polling models. Their work won praise from the committee both for its originality and for opening up new domains of application.