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Tamer Başar

Year: 
2006
Citation: 
For fundamental developments in and applications of dynamic games, multiple-person decision making, large scale systems analysis, and robust control

Tamer Başar is with the University of Illinois at Urbana-Champaign (UIUC), where he holds the positions of the Fredric G. and Elizabeth H. Nearing Endowed Professor of Electrical and Computer Engineering, Center for Advanced Study Professor, and Research Professor at the Coordinated Science Laboratory. He was born in Istanbul, Turkey, in 1946, and received B.S.E.E. degree from Robert College, Istanbul, in 1969, and M.S., M.Phil, and Ph.D. degrees from Yale University, in 1970, 1971 and 1972, respectively. He joined UIUC in 1981, after holding positions at Harvard University and Marmara Research Institute (Gebze, Turkey). He has published extensively in systems, control, communications, and dynamic games, with over 400 publications, including two books (with several editions)--one on dynamic noncooperative game theory (with G.J. Olsder), and the other one on H∞-optimal control (with P. Bernhard). He has made fundamental contributions to a diverse set of topics, including decision making under uncertainty; information structures, stochastic teams, and differential games; large scale systems; hierarchical and decentralized control; worst-case identification, estimation, and control; H∞-optimal control for linear and nonlinear systems; robust adaptive control and filtering; distributed computation; and routing, congestion control, and pricing in networks. His current research interests are in modeling and control of communication networks; control over heterogeneous networks; usage-constrained sensing, estimation and control; network economics; mobile and distributed computing; security and trustworthiness in computer networks; and risk-sensitive estimation and control. He has served in various capacities for several professional organizations, including IEEE, Control Systems Society (CSS), AACC, the International Federation of Automatic Control (IFAC), and the International Society of Dynamic Games (ISDG). He is currently the Editor-in-Chief of Automatica, Editor of the Birkhauser Series on Systems & Control: Foundations & Applications, Editor of the Annals of ISDG, and member of editorial and advisory boards of several international journals in control, wireless networks, and applied mathematics. He has received several awards and recognitions over the years, among which are the Medal of Science of Turkey (1993); Distinguished Member Award (1993), Axelby Outstanding Paper Award (1995) and Bode Lecture Prize (2004) of CSS; Millennium Medal of IEEE (2000); Tau Beta Pi Drucker Eminent Faculty Award of UIUC (2004); and the Outstanding Service Award (2005) and the Giorgio Quazza Medal (2005) of IFAC. He is a member of the National Academy of Engineering, a member of the European Academy of Sciences, a Fellow of IEEE, a Fellow of IFAC, a past president of CSS, and the founding president of ISDG.

Text of Acceptance Speech: 

June 15, 2006. Minneapolis, MN

I am honored to receive this most prestigious award and recognition by the American Automatic Control Council, named after Richard Ernest Bellman (the creator of "dynamic programming")---who has shaped our field and influenced through his creative ideas and voluminous multifaceted work the research of tens of thousands, not only in control, but also in several other fields and disciplines. In my own research, which has encompassed control, games, and decisions, I have naturally also been influenced by the work of Bellman (on dynamic programming), as well as of Rufus Isaacs (the creator of differential games) whose tenure at RAND Corporation (Santa Monica, California) partially overlapped with that of Bellman in the 1950s. I want to use the few minutes I have here to say a few words on those early days of control and game theory research (just a brief historical perspective), and Bellman's role in that development.

In a Bode Lecture I delivered (at the IEEE Conference on Decision and Control in the Bahamas) in December 2004, I had described how modern control theory was influenced by the research conducted and initiatives taken at the RAND Corporation in the early 1950s. RAND had attracted and housed some of the great minds of the time, among whom was also Richard Bellman, in addition to names like Leonard D. Berkovitz, David Blackwell, George Dantzig, Wendell Fleming, M.R. Hestenes, Rufus Isaacs, Samuel Karlin, John Nash, J.P. LaSalle, and Lloyd Shapley (to list just a few). These individuals, and several others, laid the foundations of decision and game theory, which subsequently fueled the drive for control research. In this unique and highly conducive environment, Bellman started working on multi-stage decision processes, as early as 1949, but more fully after 1952---and it is perhaps a lesser known historical fact that one of the earlier topics Bellman worked on at RAND was ! game theory (both zero- and nonzero-sum games) on which he co-authored research reports with Blackwell and LaSalle. In an informative and entertaining autobiography he wrote 32 years later ("Eye of the Hurricane", World Scientific, Singapore), completed in 1984 shortly before his untimely death (March 19), Bellman describes eloquently the research environment at RAND and the reason for coining the term "dynamic programming".

At the time, the funding for RAND came primarily from the Air Force, and hence it was indirectly under the Secretary of Defense, who was in the early 1950s someone by the name Wilson. According to Bellman, "Wilson had a pathological fear and hatred of the word 'research' and also of anything 'mathematical' ". Hence, it was quite a challenge for Bellman to explain what he was doing and interested in doing in the future (which was research on multi-stage decision processes) in terms which would not offend the sponsor. "Programming" was an OK word; after all Linear Programming had passed the test. He wanted "to get across the idea that what he was doing was dynamic, multi-stage, and time-varying", and therefore picked the term "Dynamic Programming". He thought that "it was a term not even a Congressman could object to". This being the official reason given for his pick of the term, some say (Harold Kushner--recipient of this award two years ago--being one of them, based on a personal conversation with Bellman) that he wanted to upstage Dantzig's Linear Programming by substituting "dynamic" for "linear". Whatever the reasons were, the terminology (and of course also the concept and the technique) was something to stay with us for the next fifty plus years, and undoubtedly for many more decades into the future, as also evidenced by the number of papers at this conference using the conceptual framework of dynamic programming.

Applying dynamic programming to different classes of problems, and arriving at "functional equations of dynamic programming", subsequently led Bellman, as a unifying principle, to the "Principle of Optimality", which Isaacs, also at RAND, and at about the same time, had called "tenet of transition" in the broader context of differential games, capturing strategic dynamic decision making in adversarial environments.

Bellman also recognized early on that a solution to a multi-stage decision problem is not merely a set of functions of time or a set of numbers, but a rule telling the decision maker what to do, that is, a "policy". This led in his thinking, when he started looking into control problems, to the concept of "feedback control", and along with it to the notions of sensitivity and robustness. These developments, along with the more refined notions of information structures (who knows what and when), have been key ingredients in my research for the past thirty plus years.

It is interesting that at RAND at the time (that is in the 1950s), in spite of the anti-research and anti-mathematical attitude that existed in the higher echelons of the government, and the Department of Defense in particular, fundamental research did prosper, perhaps somewhat camouflaged initially, which in turn drove the creation of modern control theory, fueled also by the post-Sputnik anxiety. There is perhaps a message that should be taken from that: "Don't give up doing what you think and believe is right and important, but also be flexible and accommodating in how you promote it".

Before closing, I want to thank all who have been involved in the nomination process and the selection process of the Bellman Control Heritage Award this year. I want to use this occasion also to acknowledge several educational and research institutions which have impacted my life and career.

First, I want to acknowledge the contributions of the educational institutions in my native country, Turkey, in the early years of my upbringing, and the comfortable research environment provided by the Marmara Research Institute I was affiliated with in the mid to late 1970s. Second, I want to acknowledge the love for research and the drive for pushing the frontiers of knowledge I was infected with during my years at Yale and Harvard in the early 1970s. And last, but foremost, I want to acknowledge the perfect academic environment I found and have still been enjoying at the University of Illinois at Urbana-Champaign---wonderful colleagues, stimulating teaching environment at the Department of Electrical and Computer Engineering, and exemplary conducive research environment at the Coordinated Science Laboratory with its top quality graduate students. I also want to recognize all students, post-docs, and colleagues I have had the privilege of having research interactions and collaborations with over the years. I thank them all for the memorable journeys in exploring the frontiers in control science and technology.

Thank you very much.