Hurwitz Memorial Lecture Series
Hurwitz Lectures 2003 at ETH Zurich
Prof. Graham C. Goodwin
HURWITZ Lecture : Finite Alphabet Control and Estimation 

Abstract: Many design problems that arise in high technology areas are characterized by the fact that the signal values are restricted to belong to a finite number of levels. These questions are sometimes called “finite alphabet” problems. Applications include onoff control, optimal audio quantization, design of finite impulse response filters having quantized coefficients, equalization of digital communication channels subject to intersymbol interference, power electronics including switched mode power supplies and control over networked communication channels. This talk will explain how this diverse class of problems can be formulated as optimization problems having finite alphabet constraints. Methods for solving these problems will be described and it will be shown that a semiclosed form solution exists. Special cases of the result include well known practical algorithms such as optimal noise shaping quantizers in audio signal processing and decision feedback equalizers in digital communication. Associated stability questions will also be addressed and several real world applications will be presented including a “live” demonstration of audio quantization. An interesting observation arising from these applications is that control engineering principles play an exciting role in many diverse areas of modern technology. Ondemand video. http://murray.newcastle.edu.au/users/staff/eegcg/Goodwin.html 
Type of Seminar: Public Seminar 
Speaker: Prof. Graham C. Goodwin Centre for Integrated Dynamics and ControlSchool of Electrical Engineering and Computer ScienceThe University of Newcastle,Callaghan NSW 2308,Australia  
Date/Time: 20031216 / 17:15  
Location: ETH Zentrum, Sternwartstr. 7/ Gloriastr. 35, Building ETF, Aula E1  
Contact Person: Prof. M. Morari  
File Download: Request a copy of this publication. 
HURWITZ Lecture : Constrained Estimation 

Abstract: Classical estimation methods, such as the well known Kalman Filter, deal with unconstrained problems. However, constraints are an integral part of many estimation problems encountered in practice. For example, a well studied problem in digital telecommunications is that of “channel equalization” to compensate intersymbol interference. Here the transmitted signal to be estimated is known to be constrained to a finite set (typically ±1). In this talk we will show how constrained estimation problems of this type can be formulated as receding horizon constrained optimization problems. These problems are similar to the more familiar constrained control problems save that there is an additional degree of freedom in estimation, namely the initial state can also be adjusted. With this caveat, many of the ideas of constrained control can be readily extended to the case of constrained estimation. The talk will illustrate the principles by reference to several practical cases including the problem of channel equalization discussed above. We will conclude the talk by showing that there exists a more technical connection between constrained control and estimation. Indeed, the linear constrained estimation problem turns out to be the formal Lagrangian dual of a particular linear optimal control problem having a special nonquadratic cost. This circle of ideas embellishes known connections between linear quadratic unconstrained control and linear quadratic filtering. Ondemand video http://murray.newcastle.edu.au/users/staff/eegcg/Goodwin.html 
Type of Seminar: Public Seminar 
Speaker: Prof. Graham Goodwin Centre for Integrated Dynamics and ControlSchool of Electrical Engineering and Computer ScienceThe University of Newcastle,Callaghan NSW 2308,Australia  
Date/Time: 20031217 / 17:15  
Location: ETH Zentrum, Gloriastr. 35, Building ETZ E8  
Contact Person: Prof. M. Morari  
File Download: Request a copy of this publication.  
Biographical Sketch: Graham C. Goodwin obtained a B.Sc (Physics), B.E (Electrical Engineering), and Ph.D from the University of New South Wales. From 1970 until 1974 he was a lecturer in the Department of Computing and Control, Imperial College, London. Since 1974 he has been with the Department of Electrical and Computer Engineering, The University of Newcastle, Australia. He is the coauthor of seven monographs, four edited volumes, and several hundred technical papers in the areas of filtering, prediction and control. Graham Goodwin is the recipient of many international prizes including the USA Control Systems Society 1999 Hendrik Bode Lecture Prize, a Best Paper award by IEEE Trans. Automatic Control, and Best Engineering Text Book award from the International Federation of Automatic Control. He is currently Professor of Electrical Engineering and Associate Director of the Centre for Integrated Dynamics and Control at the University of Newcastle, Australia. Graham Goodwin is the recipient of an ARC Federation Fellowship; a Fellow of IEEE; an Honorary Fellow of Institute of Engineers, Australia; a Fellow of the Australian Academy of Science; a Fellow of the Australian Academy of Technology, Science and Engineering; a Member of the International Statistical Institute; and a Fellow of the Royal Society, London. He has just been elected to the Swedish Royal Academy of Science, the institution that selects Nobel Prize winners. 
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