DEPARTMENT COLLOQUIUM

Sridhar Mahadevan

Michigan State University
Computer Science & Engineering

Wednesday, December 20, 2000
Computer Science Building, Room 151
4:00 PM

Faculty Host: Andrew Barto

"Scaling Sequential Decision-Making by Hierarchical Integration of Perception, Action, and Memory"

Autonomous agents, whether biological or synthetic, are faced with a difficult sequential decision-making task: how to act reliably to achieve long-term goals despite significant uncertainty in perception and action?

Using recent developments in the field of machine learning and adaptive control, this talk will describe a general approach that uses hierarchical spatio-temporal abstraction to simplify the problem of deciding how to act. Perception, action, and memory are modeled in a unified way as temporally extended processes, amenable to adaptation and control by agents through a process of interactive learning with their environment. A general statistical framework based on hierarchical Markov models provides a theoretical underpinning for modeling temporally extended processes. This framework also facilitates exploiting task and behavioral hierarchy and modularity. Control is achieved through greedy action selection, based on maximizing values that predict long-term outcomes under uncertainty.

Drawing upon recent work of my research group, we will present several case studies that illustrate the interdisciplinary scope of this approach, ranging from models of visual attention and recognition in humans and gaze control in machines, to multi-agent coordination in manufacturing and scheduling, and spatial navigation in insects and robots.

Sridhar Mahadevan is an Associate Professor in the Department of Computer Science and Engineering at Michigan State University. He has received several awards for his research and teaching, including the NSF CAREER Award, the MSU Withrow Distinguished Scholar Award, and the MSU Teacher Scholar Award. He is currently an Editor of the Machine Learning journal, and on the editorial boards of the Journal of AI Research, and the Journal of Machine Learning Research. He has served on the program committees of AAAI, ICML, IJCAI, IROS, and NIPS conferences. Most recently, he was an Area Chair for ICML 2000 and NIPS 2000. In 1996, he organized the NSF Workshop on Reinforcement Learning, one of four planning workshops for the NSF foundation-wide $100 million Initiative on Knowledge and Distributed Intelligence. With NSF support, he also established the Reinforcement Learning Repository, the world's leading web-accessible resource on this topic featuring contributions from over a hundred scholars from around the world. He is one of the principal founders of the cognitive science program at MSU, involving 50 faculty from twenty departments across five colleges, and an organizer of the annual Distinguished Lecture Series. His research is supported by grants from NSF KDI, DARPA Distributed Robotics and MARS Programs, and MSU Strategic Partnership Funds. He has mentored many students, including Natalia Hernandez-Gardiol (winner of the 2000 CRA award for most outstanding undergraduate CS student). At ICML-99, his paper coauthored with his PhD student Gang Wang, was nominated for the Best Paper Award.

Refreshments at 3:30 PM in the Atrium, outside the presentation room.