Samuel D. Conte Distinguished Lecture Series


Prof. Pravin Varaiya
University of California, Berkeley

December 4, 4:30PM
MATH 175


We suggest an approach to the design of autonomous systems involving multiple vehicles, sensors, and communications devices that can carry out a variety of missions. The basic hypothesis is that the missions can be constructed by combining a common set of tasks executed by control agents with limited capability.

The agents are organized in a hierarchy. The organization defines authority--upper layer agents assign tasks to lower layers, and capability--upper layer agents realize more abstract functions out of more concrete, lower layer functions. Such organizations are well described as interconnected hybrid systems. SHIFT is a language that supports such descriptions.

The understanding of hierarchical systems involves two semantics. The computational view leads to a `one-world' semantics in which syntactical constructs at higher layers are `compiled' into a single interpretation at the lowest level. However, hierarchical systems are designed and analyzed using a `multi-world' semantics, with a separate interpretation at each layer. A tentative reconciliation of the two views is proposed.

Pravin Varaiya is Nortel Networks Distinguished Professor of Electrical Engineering and Computer Science at the University of California, Berkeley, and Director of Califonia PATH, a multi-university program of research in Intelligent Transportation Systems. From 1975 to 1992 he was Professor of Economics at Berkeley. He has taught at MIT and the Federal University of Rio de Janeiro. He was a member of the technical staff at Bell Laboratories during 1962-63. Dr. Varaiya has held a Guggenheim Fellowship and a Miller Research Professorship. He is a Fellow of IEEE, and a member of the National Academy of Engineering. His areas of research are communication networks, transportation systems, and electric power systems. He has published more than 200 papers in technical journals. He is on the editorial board of Transportation Research Part C,; Discrete Event Dynamical Systems: Theory and Applications; Journal of Economic Dynamics & Control; Birkhauser series on Progress in Systems and Control Theory. The second edition of his book, "High-performance communication networks," with Jean Walrand, is published by Morgan-Kaufmann.

The Network Systems Colloquium is sponsored by the Network Systems Lab at Purdue University. For further information, please contact Kihong Park ( or 765-494-7821).