IEEE Computer Society Orlando Chapter

Analysis of continuous dynamical systems using statistical model checking

Dr. P.S. ThiagarajanDepartment of Computer Science

National University of Singapore (NUS)

Where: Engineering-I Conference Room 288, University of Central Florida

When: Wednesday September 25 from 5pm to 6pm

Abstract: Systems with real-valued variables evolving continuously w.r.t. time arise in many settings including cyber-physical systems and biochemical networks. The dynamics of these variables will be typically specified in terms of differential equations. An important verification task is to determine whether the global behavior of the system has the required reachability properties. The number of the real-valued variables can be large and their dynamics can be non-linear. Further, there can be multiple modes of behavior where each mode is governed by a different system of differential equations. Hence such systems can seldom be analyzed effectively let alone efficiently. We advocate statistical model checking as an approximate but scalable analysis technique in these settings. The basic idea is to assume a probability distribution over the initial states of the system. This in turn -under suitable continuity assumptions- induces a distribution over the trajectories originating from the initial states. Hence one can construct a statistical model checking procedure to verify interesting dynamical properties using a simple sequential hypothesis testing method. We demonstrate the applicability of this approach using a number of bio-pathway models.

Brief Bio: P.S. Thiagarajan received his B.Tech (Electrical Engineering) from the Indian Institute of Technology (IIT), Madras (1970) and his Ph.D. in Computer Science from Rice University, Houston, Texas, USA (1973). He has been a Research Associate at Project MAC (the predecessor of the current Laboratory for Computer Science), Massachusetts Institute of Technology (MIT) (1973-1975), a Research Scientist at the Gesellschaft fuer Mathematik und Datenverarbeitung, St. Augustin, Germany (1975-83), a Lektor (Associate Professor) at the Computer Science Department of Aarhus University, Aarhus, Denmark (1983-86), an Associate Professor at The Institute of Mathematical Sciences, Chennai, India (1986-89) and a Professor at the Chennai Mathematical Institute (1989-). He was a visiting professor in the School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, USA during 2000-2001. He is a Fellow of the Indian Academy of Sciences and the Indian National Academy of Sciences. He has served as a member of the editorial boards of the journals Theoretical Computer Science and the International Journal on Foundations of Computing . He served two terms (1997 - 2003) as a member of the Governing Council of the European Association for Theoretical Computer Science (EATCS).