After my graduation I wanted to do a Ph.D. in Mathematics, but my father convinced me to stick to Computer Science (sound advice in hindsight!). So I started graduate school at the Computer Science Department at Stanford University , and worked in the Theory Division with Professor Vaughan Pratt. I worked on algebraic models for concurrent computation, in the style of Petri Nets, CCS and Event Structures, and eventually came up with my model called Chu Spaces. Chu Spaces, or gates, can be used to model network behavior, and subsume the behaviors describable by Petri Nets, CCS and CSP. They are simple and asynchronous, and possess an elegant process algebra and a formal verification system based on linear logic. They also provide a translation between imperative and declarative programs.
In spring 1993 Prof. Pratt recommended me to Vijay Saraswat at Xerox PARC, and I worked here for the summer, laying the foundations of integrating Concurrent Constraint Languages with Reactive Systems. I graduated from Stanford in 1994, and joined PARC to work on a NASA project for modeling electromechanical systems. In September 1997 I moved to the NASA Ames Research Center, to work at the Autonomous Systems Group on using hybrid modeling and analysis for building model-based autonomous systems.
In January 2000 I joined Stratify Inc. (then PurpleYogi Inc.) as a member of the research staff. I worked on a variety of topics there, including document classification, document analysis, and multilingual classification, among others. In March 2003, I joined Google Inc., and have been working on Search Quality. I also continue to work on the modeling and analysis of probabilistic and hybrid systems.