E-LETTER on Systems, Control, and Signal Processing ISSUE No. 41, 7 May 1991 Editors: Bradley W. Dickinson bradley@princeton.edu or bradley@pucc.bitnet Eduardo D. Sontag sontag@hilbert.rutgers.edu or sontag@pisces.bitnet Welcome. We remind you that items for posting can be emailed to either of the editors. PLEASE SEND CONTRIBUTIONS, since the eletter can only be useful if everyone participates. A REQUEST: It would be useful if articles are already sent in the format that we use, starting with a "Contributed by:..." and a title centered in the next line. In addition, please provide a 60-character title for the Contents. Thanks! NOTE: if you are using an editor to read this mailing and if at any point you wish to skip to the next article, you can accomplish this by searching for the string: *.** Contents Changes to mailing list Personals: People on the move People going up Awards and Recognitions IEEE Control Systems Society News: Chapter Activities CSS Technology Award, Call for nominations SIAM Activity Group in Control and Systems Theory: SIAM Conf on Control & Applics, Minneapolis, Sept 16-18, 1992 Request for suggestions Journals: Table of Contents, CSSP 10,3 Table of Contents, IEEE-IT July 1991 Table of Contents, LAA 152 LAA: Special Issues in Progress Conferences: SIAM Conf Applied Linear Algebra, Minneapolis, Sept 11-14, 1991 (See above for '92 Control Conference) IFAC Wrkshp. on Sys.Structure & Control, Prague, Sept. 3-5,1992 Call for Papers for the 1992 IEEE Symposium on CACSD Diff Games and Robust Control, May 17 - 18, 1991, Santa Barbara Books Published: Principles of Power Electronics, Kassakian/Schlecht/Verghese Adaptive Optimal Control, Bitmead/Gevers/Wertz Continuous System Modeling, Cellier Faculty Positions Available: Search for Chair, Dept. of Systems Sci and Mathematics, Wash U Interdisciplinary Engineering Prog., Australian National Univ. Image sequence processing, Bilkent Univ., Ankara, Turkey Reports available: Minimum Stability Degree of Parameter-dependent Linear Systems Misc: Standards for Control CAD Software Graduate Programs in Control Systems at Imperial College *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by the Editors: Changes/Additions to mailing list. Changes and Updates: ------------------- shuli@jhuvms.hcf.jhu.edu (Shuli C. Shwartz, Johns Hopkins Univ.) shynk@ece.ucsb.edu (John J. Shynk, Univ. of California, Santa Barbara) abed@src.umd.edu (Eyad Abed, Univ. of Maryland, College Park) cullumj@watson.ibm.com (Jane Cullum, IBM T.J.Watson Res.Ctr, Yorktown Hgts.,NY) gconte@anvax2.cineca.it (G. [Pino] Conte, Ancona, Italy) laffer@gemini.mth.pdx.edu (Gerardo Lafferriere, Portland State Univ., OR) prince@mashie.ece.jhu.edu (Jerry Prince, Johns Hopkins Univ.) fapglass@cugsbvm.columbia.edu (Paul Glasserman, Columbia Univ. Sch.of Business) neuhoff@eecs.umich.edu (Dave Neuhoff, Univ. of Michigan, Ann Arbor) janeye@cc.umontreal.ca (Jane (Juan Juan) Ye, Univ. of Montreal, PQ, Canada) dcm@bhpmrl.oz.au (Duncan McFarlane, BHP Melbourne Research Labs, Australia) R0814@CSUOHIO.BITNET (Zhiqiang Gao, Cleveland State Univ.) luh@farside.ese.uconn.edu (Peter B. Luh, Univ. of Connecticut, Storrs) hatke@ll.mit.edu (Gary Hatke, MIT Lincoln Labs, Lexington, MA) keller@ll.mit.edu (Kathy Keller, MIT Lincoln Labs, Lexington, MA) drepperge@EAGLE.AAMRL.WPAFB.AF.MIL (Daniel Repperger, Wright Patterson AFB, OH) Additions: --------- hms@cec1.wustl.edu (Heinz Schattler, Washington Univ., St. Louis) eefacev@prism.gatech.edu (Erik Verriest, Georgia Inst. of Technology, Atlanta) yuanyin@utdallas.edu (Yuanyin Wu, Univ. of Texas, Dallas) matthews@isi.ethz.ch (Michael B. Matthews, ETH Zurich, Switzerland) roger@isy.liu.se (Roger Germundsson, Linkoping Univ., Sweden) krister@isy.liu.se (Krister Forsman, Linkoping Univ.,Sweden) zafiriou@src.umd.edu (Evanghelos Zafiriou, Univ. of Maryland, College Park) ap1asiz@primea.sheffield.ac.uk (Alan Zinober, Univ. of Sheffield, UK) raoul@ifr.ethz.ch (Raoul Herzog, ETH Zurich, Switzerland) ENSUNDARA@NTIVAX.BITNET (N.Sundararajan, Nanyang Tech. Univ., Singapore) EJLWANG@NTIVAX.BITNET (Jianliang Wang, Nanyang Tech. Univ., Singapore) joshi@scb3.larc.nasa.gov (Suresh M. Joshi, NASA Langley Research Ctr., VA) onural@trbilun.bitnet (Levent Onural, Bilkent University, Ankara, Turkey) JHDCI@UNO.EDU (Jack DeGolyer, Univ. of New Orleans) pet101@ukcc.uky.edu (Jamer Tittle, Univ. of Kentucky, Lexington) dadong@ecn.purdue.edu (Dong Da, Purdue Univ., W. Lafayette, IN) marc@cs.kuleuven.ac.be (Marc Van Barel, Katholieke Univ. Leuven, Belgium) grino@ic.upc.es (Robert Grino, Inst. de Cibernetica, Barcelona, Spain) arikan@sdr.slb.com (Orhan Arikan, Schlumberger-Doll Research, Ridgefield CT) guos@eecae.ee.msu.edu (Shixiong Guo, Michigan State Univ. E. Lansing) howard@cs.stanford.edu (Howard Wong-Toi, Stanford Univ.) danai@umaecs.bitnet (Kourosh Danai, Univ. of Massachusetts, Amherst) leandros@cspl.src.umd.edu (Leandros Tassiulas, Univ. of Maryland, College Park) *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by the Editors -- PERSONALS ********** PEOPLE ON THE MOVE ************ (1) Dr. James Wei, currently Professor and former Head of Chemical Engineering at MIT will join the faculty and assume the position of Dean of the School of Engineering and Applied Science at Princeton University in time for the 1991-92 academic year. Many E-Letter readers will know his work dealing with Lie algebraic analysis of solutions of linear differential equations (particularly the "Wei-Norman product formula") which has been widely cited in the systems literature. (2) Dr. N. Sundararajan has recently moved from India to Singapore where he has been appointed to a faculty position in the School of Electrical and Electronic Engg., Nanyang Technological University. Tel: 660-5027. email: ENSUNDARA@NTIVAX.BITNET ********** AWARDS AND RECOGNITION ************ (1) Two recent announcements of honors for Roger Brocket have been made. Roger will receive the 1991 IEEE Control Systems Heritage Award. He has also been elected to membership in the National Academy of Engineering. (2) Gene Golub will be awarded an honorary degree from the Univ. of Illinois at Urbana-Champaign during the May 1991 Commencement. (3) David D. Yao, Professor of Industrial Engineering and Operations Research at Columbia University, has been awarded a Guggenheim Fellowship for a project, ``Studies on the Algebraic Structure of Discrete Event Systems''. ******* CHANGES OF ADDRESS, PHONE, ETC ******* (1) Telephone for Luciano Pandolfi: Old Number 556 7516; New Number 564 7516 (New FAX number: OLD FAX NUMBER 556 7599; NEW FAX NUMBER 564 7516) ******* send us more information for the gossip column!!! ******* *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by D.W. Repperger, Chairman, Chapter Activities (please note my new email address:) drepperge@EAGLE.AAMRL.WPAFB.AF.MIL "Chapter Activities Around The World" * *** ** ** *CSS* ** IEEE ** *** ** Control Systems ** ** Society ** ** Chapter Activities ** ** Around The ** ** World ** ** ** * (1) Contributed by Caio Ferreira, Rockford, Illinois: Dr. Bernard Friedland gave a Distinguished Lecturer presentation on April 25, 1991. (2) Contributed by Luis Ferrans, Huntsville, Alabama: (a)On March 15th, 1991, Jack Furbush of McDonnell Douglas Space Systems Company presented a talk, "Development of An Engineering Visualization System Using Quadric Surface". (b) On April 19, 1919, Dr. Haik Biglari of Sverdrup Technology presented a seminar on, "Application Generator" at BDM International, Huntsville. (3) Contributed by Soh Cheong Boon, Singapore Section: The IEEE Singapore Section of the IEEE Control Systems Society will help sponsor an International Conference on Intelligent Control & Instrumentation (ICICI,92) on 18-21 February, 1992 at the Hotel Hilton, Singapore. Please contact Professor C. C. Hang, 200 Jalan Sultan, # 11-03 Textile Center, Singapore 0719 for further information. (4) Interested in starting a new CSS local chapter??? This is relatively easy to do. You can form a new local chapter, revive a former chapter, or form a CSS chapter in conjunction with another society. Please contact drepperge@EAGLE.AAMRL.WPAFB.AF.MIL for the form and details. It is not difficult to do anywhere in the world. (5) The IEEE Control Systems Society sponsors a Distinguished Lecturer's Program which pays 50% of travel expenses ($700 max within a continent and $1400 max across two continents). This program can be used internationally and it covers a wide variety of topics. Please contact drepperge@EAGLE.AAMRL.WPAFB.AF.MIL for either: (1) A short (1.2 page) brochure of all 10 speakers and topics, or: (2)The complete brochure (8.4 pages) with all abstracts. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Juergen Ackermann, DLR, 8031 Oberpfaffenhofen, Germany April 26, 1991 Call for nominations CSS Technology Award For the third time the IEEE Control Systems Society announces the Control Systems Technology Award, to be given to an individual or team for outstanding contributions to control systems technology, either in design and implementation or in project management. The award consists of $ 1,000 and a plaque. Nominations are now invited for this award. While no special nomination format is required, the nomination letter should indicate clearly the nature and impact of the contribution, and should also provide documentation (patents, publication lists, reports, etc.) supporting the nomination. Up to three letters from individuals other than the nominator who are familiar with the contribution may be included. All submissions must be received no later then JUNE 30, 1991 by the Chairman of the Technology Award Committee: Juergen E. Ackermann DLR-FF-DF 8031 Oberpfaffenhofen Germany Fax 49-8153-281134 The selection committee reflects a variety of control technology and applications areas: E. Bristol, Foxboro E.O. King, ALCOA W.F. Powers, Ford J.L. Melsa, Tellabs A. Spang, General Electric The award is an important initiative by the Society to recognize practitioners and developers of significant control technology. You are strongly urged to take part in this endeavor by identifying highly qualified nominees. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: KGRASSE@nsfuvax.math.uoknor.edu (Kevin A. Grasse) PRELIMINARY ANNOUNCEMENT SIAM CONFERENCE ON CONTROL AND ITS APPLICATIONS September 16-18, 1992 Radisson Hotel Metrodome Minneapolis, Minnesota, USA SCOPE AND AIMS OF THE CONFERENCE The SIAM Activity Group on Control and Systems Theory is pleased to announce a conference on control theory and its applications, to be held in Minneapolis, Minnesota, USA, on September 16-18, 1992. Minneapolis is the location of the Institute for Mathematics and Applications (IMA), which will be conducting a special year in Control Theory and Its Applications during the 1992-1993 academic year. The conference will cover a broad range of topics that are of current interest in control theory and will bring together researchers in control theory and its applications from academe, industry, and the government. The conference will include plenary and simultaneous one-hour lectures, minisymposia, and sessions for contributed papers. ORGANIZING COMMITTEE K. A. Grasse (Chair), A. Manitius (co-Chair), E. D. Sontag (co-Chair), Y. Arkun, H. T. Banks, L. D. Berkovitz, S. L. Campbell, M. H. A. Davis, A. Friedman, J. W. Helton, H. Hermes, G. Leugering, S. I. Marcus, E. Polak, J. Willems CALL FOR MINISYMPOSIUM ORGANIZERS Anyone interested in organizing a minisymposium for this conference should contact K. A. Grasse by electronic mail at kgrasse@nsfuvax.math.uoknor.edu or by ordinary mail at the following address: Professor Kevin A. Grasse Department of Mathematics University of Oklahoma Norman, OK 73019 USA CALL FOR CONTRIBUTED PAPERS A formal call for contributed papers will be made at a later date in this newsletter, the SIAM NEWS, and other places. All members of the SIAG in Control and Systems Theory are strongly encouraged to contact the conference organizer with their suggestions regarding the conference. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Eduardo Sontag, sontag@control.rutgers.edu The above conference announcement is the major activity planned by the SIAG for the next two years. However, other, more specialized conferences, may be desirable. Please send your ideas for any other SIAG activities! --E.D. Sontag, SIAG Program Director *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: zeman@sbee.sunysb.edu (A.H.Zemanian) TABLE OF CONTENTS CIRCUITS, SYSTEMS, AND SIGNAL PROCESSING Vol. 10, No. 3, 1991. On Reduced Polynomial-Based Split Algorithms, Hari Krishna Comparative Performance Study of Element-Space and Beam-Space MUSIC Estimators, Petre Stoica and Arye Nehorai The Classification Properties of the Pecstrum and its Use for Pattern Identification, V.Anastassapoulos and A.N.Venetsanopoulos Direction-of-Arrival Estimation in Applications with Multipath and Few Snapshots, Arye Nehorai, David Starer, and Petre Stoica On the Existence and Uniqueness Theory for Nonlinear Differential-Algebraic Equations, Sebastian Reich Robust Stability and Sensitivity of Input-Output Systems over Extended Spaces. Part I: Robust Stability, Vaclav Dolezal *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Costas N. Georghiades, Publications Editor. IEEE Transactions on Information Theory Contents of the July 1991 issue AUTHOR(S) TITLE REGULAR PAPERS T. Kasami On Multi-Level Block Modulation Codes T. Takata T. Fujiwara and S. Lin Z. Zhang Limiting Efficiencies of Burst Correcting Array Codes C.T. Retter Orthogonality of Binary Codes Derived from Reed-Solomon Codes A. Orlitsky Worst-Case Interactive Communication II: Two Messages are Not Optimal M.K. Varanasi Optimally Near-Far Resistant Multiuser Detection and B. Aazhangin Differentially Coherent Synchronous Channels S. Mallat Zero-Crossings of a Wavelet Transform A.R. Barron Minimum Complexity Density Estimation and T.M. Cover A.H. Tewfik Internal Models and Recursive Estimation for 2-D B.C. Levy Isotropic Random Fields and A.S. Willsky N. Merhav A Bayesian Approach for Classification of Markov and J. Ziv Sources N. Moayeri Theory of Lattice-Based Fine-Coarse Vector and D.L. Neuhoff Quantization I.H. Witten The Zero Frequency Problem: Estimating the and T.C. Bell Probabilities of Novel Events in Adaptive Text Compression R.M. Capocelli New Bounds on the Redundancy of Huffman Codes and A. De Santis E. Masry Multivariate Probability Density Deconvolution for Stationary Random Processes S.D. Blostein Quickest Detection of a Time-Varying Change in Distribution G. Di Blasio Modified Q-Functions and Their Use in Detection and A. Neri Analysis R. Ahlswede Reusable Memories in the Light of the Old Varying and G. Simonyi and a New Outputwise Varying Channel Theory CORRESPONDENCE ITEMS F. Kanaya On the Practical Implication of Mutual and K. Nakagawa Information for Statistical Decision-Making J. Ramanathan On the Wavelet Transform of Fractional and O. Zeitouni Brownian Motion Y. Baram Encoding Unique Global Minima in Nested Neural Networks B. Apolloni Learning by Parallel Boltzmann Machines and D. de Falco G. Gabor On the Gaarder-Slepian Tracking System G. Szekeres Conjecture and Z. Gyorfi T. Koski On Quantizer Distortion and the Upper Bound for and L. Persson Exponential Entropy E. Masry Flicker Noise and the Estimation of the Allan Variance S.J. Yakowitz Some Contributions to a Frequency Location Method due to He and Kedem R. Johannesson Strengthening Simmons' Bound on Impersonation and A. Sgarro X. Zhang Two-Dimensional Harmonic Retrieval and Its Time-Domain Analysis Technique J.T. Barnett Zero-Crossing Rates of Functions of Gaussian and B. Kedem Processes J. Snyders Reduced Lists of Error Patterns for Maximum Likelihood Soft Decoding S. Sakata Decoding Binary 2D Cyclic Codes by the 2D Berlekamp-Massey Algorithm I.S. Honkala On (k,t)-Subnormal Covering Codes W.C. Huffman On Extremal Self-dual Quaternary Codes of Lengths 18 to 28, II G. Seroussi A Systolic Reed-Solomon Encoder A. Lempel Explicit Formulas for Self-Complementary and G. Seroussi Normal Bases in Certain Finite Fields R.A. Brualdi Weight Enumerators of Self-Dual Codes and V.S. Pless N. Nakatsu Bounds on the Redundancy of Binary Alphabetic Codes A.J. van Zanten Index System and Separability of Constant Weight Gray Codes *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Hans Schneider LAA CONTENTS, Volume 152, July 1, 1991 (Interior Point Methods for Linear Programming) Special Editors: David M. Gay, Masakazu Kojima, and Richard Tapia Preface 1 Yinyu Ye (Iowa City, Iowa) and Panos M. Pardalos (University Park, Pennsylvania) A Class of Linear Complementarity Problems Solvable in Polynomial Time 3 Robert M. Freund (Cambridge, Massachusetts) Theoretical Efficiency of a Shifted-Barrier-Function Algorithm for Linear Programming 19 D. den Hertog, C. Roos, and T. Terlaky (Delft, The Netherlands) A Potential-Reduction Variant of Renegar's Short-Step Path-Following Method for Linear Programming 43 Panos M. Pardalos (University Park, Pennsylvania), Yinyu Ye (Iowa City, Iowa), and Chi-Geun Han (University Park, Pennsylvania) Algorithms for the Solution of Quadratic Knapsack Problems 69 Michael J. Todd (Ithaca, New York) The Affine-Scaling Direction for Linear Programming Is a Limit of Projective-Scaling Directions 93 Robert J. Vanderbei (Murray Hill, New Jersey) Splitting Dense Columns in Sparse Linear Systems 107 K. Kim and J. L. Nazareth (Pullman, Washington) The Decomposition Principle and Algorithms for Linear Programming 119 Masakazu Kojima (Tokyo, Japan) and Nimrod Megiddo (Tel Aviv, Israel) The Relation Between the Path of Centers and Smale's Regularization of the Linear Programming Problem 135 Kathryn Turner (Logan, Utah) Computing Projections for the Karmarkar Algorithm 141 Shinji Mizuno (Tokyo, Japan) O(nrL)-Iteration and O(n3L)-Operation Potential Reduction Algorithms for Linear Programming 155 K. O. Kortanek, Florian Potra, and Yinyu Ye (Iowa City, Iowa) On Some Efficient Interior Point Methods for Nonlinear Convex Programming 169 Irvin J. Lustig (Princeton, New Jersey), Roy E. Marsten (Atlanta, Georgia), and David F. Shanno (New Brunswick, New Jersey) Computational Experience With a Primal-Dual Interior Point Method for Linear Programming 191 Kurt M. Anstreicher (New Haven, Connecticut) On Monotonicity in the Scaled Potential Algorithm for Linear Programming 223 Sanjay Mehrotra (Evanston, Illinois) On Finding a Vertex Solution Using Interior Point Methods 233 Stefano Herzel, Maria Cristina Recchioni, and Francesco Zirilli (Roma, Italy) A Quadratically Convergent Method for Linear Programming 255 David M. Gay (Murray Hill, New Jersey) Massive Memory Buys Little Speed for Complete, In-Core Sparse Cholesky Factorizations on Some Scalar Computers 291 Paul D. Domich (Boulder, Colorado), Paul T. Boggs (Gaithersburg, Maryland), Janet E. Rogers (Boulder, Colorado), and Christoph Witzgall (Gaithersburg, Maryland) Optimizing Over Three-Dimensional Subspaces in an Interior-Point Method for Linear Programming 315 R. A. Tapia (Houston, Texas) and Yin Zhang (Catonsville, Maryland) An Optimal-Basis Identification Technique for Interior-Point Linear Programming Algorithms 343 Author Index 365 ******************************************************************** Special Issues in Progress 1. Iterations in Linear Algebra and Its Applications (Dedicated to G. H. Golub, R. S. Varga, and D. M. Young); special editors are O. Axelsson, J. de Pillis, M. Neumann, W. Niethammer, and R. J. Plemmons. To appear as Volumes 154/155, August/September 1991. 2. Algebraic Linear Algebra; special editors are Robert M. Guralnick, William H. Gustafson, and Lawrence S. Levy. To appear as Volume 157, October 15, 1991. 3. Proceedings of the Auburn 1990 Matrix Theory Conference; special editors are David Carlson and Frank Uhlig. Submission deadline: August 1, 1990. Details provided with the conference announcement. 4. Proceedings of the Sixth Haifa Conference on Matrix Theory; special editors are A. Berman, M. Goldberg, and D. Hershkowitz. Submission deadline: October 1, 1990. Details provided with the conference announcement. 5. Proceedings of the International Workshop on Linear Models, Experimental Designs and Related Matrix Theory, (August 6-8, 1990, Tampere, Finland); special editors are Jerzy K. Baksalary and George Styan. Submission deadline: October 31, 1990. Details provided with the conference announcement. 6. Proceedings of the Second NIU Conference on Linear Algebra, Numerical Linear Algebra and Applications, (May 3-5, 1991, Northern Illinois University, DeKalb, Illinois); special editors are Biswa Dutta and Robert Plemmons. Submission deadline: July 31, 1991. Details provided with the conference announcement. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: SIAMCONFS@wilma.wharton.upenn.edu Fri Apr 12 15:12:27 1991 SIAM Conference on Applied Linear Algebra September 11-14, 1991, Minneapolis, Minnesota Dear Colleague: Just a friendly reminder...... the deadline for submission of abstracts for presentation at the SIAM Conference on Applied Linear Algebra is April 19. You can submit your abstracts (approximately 100 words in length) by fax to: 215-386-7999 e-mail to: siamconfs@wharton.upenn.edu phone to: 215-382-9800 Include title of presentation, preference (15-minute lecture format, or poster presentation), full name and affiliation (speaker and coauthors), and name of conference. We look forward to your participation. See you in Minneapolis. Richard A. Brualdi Conference Chair *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: flewis@arrirs03.uta.edu (Frank Lewis) Call for papers for the second IFAC Workshop on System Structure and Control, V. Kucera organizer. The workshop will be held in Prague, Sept. 3-5, 1992. The topics include linear systems, nonlinear systems, algebraic and geometric methods, implicit systems, invariants, control, stability, numerical methods, and others. A Call for papers is available from F. Lewis, EE Dept., UTA, Arlington, TX, 76012 or from V. Kucera. The deadline ffor abstracts and special session proposals is 10 Jan. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: John R. James CACSD '92 1992 IEEE Symposium on Computer-Aided Control System Design Crown Sterling Suites Hotel (formerly Embassy Suites Hotel) Napa, California March 17-19, 1992 The 1992 IEEE Symposium on Computer-Aided Control System Design (CACSD) is organized by the Control Systems Society (CSS) Technical Committee on CACSD, and is sponsored by the CSS. The Symposium is a three-day event to be held >from 17 to 19 March, 1992 at the Crown Sterling Suites Hotel (formerly Embassy Suites Hotel) in Napa, California. The General Chairman of the Symposium is John James of the United States Army. The Symposium provides a forum for the presentation and discussion of the multidisciplinary theoretical and implementation issues associated with the life cycle of control software for computer-controlled systems. The central issues in this process continue to be associated with the application of off-line techniques for the analysis and design of controllers. The Symposium will contain presentations of both contributed and invited papers. Both theoretical and applied papers are solicited in the following and related areas: - Computer-Aided Modeling, Analysis and Design Environments, including: Man-machine interface Graphics and animation Numerical methods Artificial Intelligence Symbolic methods Object-oriented methods Expert systems Databases - Mathematical Foundations and Formal Methods - Real-Time Operating Systems - Implementation Issues, including Verification and Validation - Advanced Modeling Concepts - Simulation - Artificial Intelligence, Expert Systems, and Machine Learning - Computer-Assisted Optimization - Benchmarking - Standards, data exchange - Educational aspects - Applications All papers which are accepted for presentation will be published in a Proceedings, which will be available at the Symposium. INSTRUCTIONS TO AUTHORS Prospective authors should submit five (5) copies of the full paper, headed with the paper title, names, affiliations, and complete mailing addresses of all authors, and the statement "CACSD '92". The first-named author will be used for all correspondence unless otherwise stated. Submissions must be made by September 1, 1991 to: CACSD '92 Prof. Grantham Pang Department of Electrical Engineering University of Waterloo Waterloo, Ontario N2L3G1 Canada phone: (519) 885-1211 email: pang@watale.watmath.edu Authors will be notified regarding acceptance of their papers for presentation at the CACSD '92 by December 15, 1991. Authors of accepted papers will be provided publication kits and instructions for preparation of their manuscripts for the Proceedings. Manuscripts are restricted to eight Proceedings pages or less. Excess page charges of $100.00 per page will be assessed. Authors of accepted papers are expected to attend the Symposium to present their work. The registration fee for one author is required when the manuscript is returned on conference mats as a condition of publication. CACSD '92 COMMITTEE GENERAL CHAIRMAN John James (USA) FINANCE CHAIRMAN Harold Javid (USA) LOCAL ARRANGEMENTS CHAIRMAN Charles Herget (USA) PROGRAM CHAIRMAN Grantham Pang (CDN) PROGRAM COMMITTEE James Albus (USA), Ernest Armstrong (USA), Karl Astrom (S), Derek Atherton (GB), Ruzena Bajcsy (USA), John Baras (USA), Keith Belvin (USA), Douglas Birdwell (USA), Stephen Boyd (USA), Zhen-Yu Chen (PRC), Norman Coleman (USA), Ted Davison (CDN), Dean Frederick (USA), Donald Gavel (USA), Brian Glass (USA), Suresh Joshi (USA), Richard Klabunde (USA), Alan Laub (USA), Alexander Levis (USA), Jane Liu (USA), Lennart Ljung (S), Jan Maciejowski (GB), Erik Mettala (USA), Neil Munro (GB), Anil Nerode (USA), John Painter (USA), Magnus Rimvall (USA), Austin Spang (USA), Paul Travers (USA), Zheng-Zhong Wang (PRC), Carla Wong (USA), W. Murry Wonham (CDN), Lotfi Zadeh (USA) phone: (804) 727-3948/3945 AV: 680-3948 FAX: (804) 727-4007 email: jamesj%mon1@leav-emh.army.mil snailmail: HQ TRADOC, ATRM-K (COL James), Ft Monroe, VA 23651 *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Center for Control Engineering and Computation University of California Santa Barbara, CA Workshop on Differential Games and Robust Control May 17 - 18, 1991 May 17, Friday, UCEN Room 1 Short Course on $H_\infty$-Optimal Control and Differential Games I Tamer Basar, University of Illinois 9:00 - 9:50: An Introduction to $H_\infty$-Optimal Control Theory, and Relationship with Differential Games 10:00 - 11:00 Discrete-time Problem with State Measurements Sessions 11:15 - 12:00 Branch and Bound Algorithm for Computing the Minimum Stability Degree of Parameter Dependent Linear Systems Stephen Boyd, Stanford University 2:00 - 2:45 Robust Control John C. Doyle, Caltech 3:00 - 3:45 Parametrically Dependent Quadratic Stabilization of Parametrically Dependent Linear Systems Andrew Packard, University of California, Berkeley 4:00 - 4:45 Analysis with Measured Signals Roy Smith, University of California, Santa Barbara May 18, Saturday, UCEN Room 3 Short Course on $H_\infty$-Optimal Control and Differential Games II Tamer Basar, University of Illinois 9:00 - 9:50 Continuous-time Problem with Perfect and Sampled State Measurements 10:00 - 11:00 Minimax Designs under Imperfect State Measurements Sessions: 11:15 - 12:00 Robust Control of Hybrid Continuous/Discrete Time Systems Bassam Bamieh, Rice University 2:00 - 2:45 Optimal Disturbance Rejection Over General Signal Spaces M. Dahleh, University of California, Santa Barbara 3:15 - 3:45 Game-Theoretic Approach to Identification M. A. Dahleh, MIT 4:00 - 4:45 Linear Controller Design via Convex Programming Craig Barratt, Stanford University * Each speaker will lecture for 45 minutes. * For more information contact: Mohammed Dahleh at (805)893-2704, e-mail: dahleh@alpo.ucsb.edu, or Roy Smith at (805)893-2967. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: verghese@lees.mit.edu (George Verghese) ---> NEW TEXTBOOK ON POWER ELECTRONICS <--- Those of you who work on applications of control in power systems of various kinds may find the following book interesting, because of the attention it pays to the dynamics and control of power electronic circuits: Principles of Power Electronics, by John Kassakian, Martin Schlecht, and George Verghese (all at MIT) Addison-Wesley 1991 ISBN 0-201-09689-7 738 pages, 462 figures, hardcover, $64.00 Power electronic circuits use electronic switches, inductors, capacitors, and transformers to perform high-efficiency conversion of electrical energy from the form supplied by a source to the form demanded by a load. These circuits are most commonly found around us in the switching power supplies now routinely used in computers and other comparable electronic equipment, but they are also critically important in various high-power applications (traction, HVDC transmission, etc.). Power electronic circuits are interesting from a control viewpoint for several reasons, but especially because (i) the only available control variables are the time instants at which some of the switches are opened or closed (while the remaining switch transitions are functions of the state), and (ii) the circuit properties of the controlled plant can play a significant role in the analysis and design of a control scheme. This book is intended as a text for use at the senior/ graduate level, as well as by working engineers and researchers in power electronics. It seems to be the first book in power electronics that gives issues of dynamics and control a prominent place. Its 25 chapters are arranged in four parts, and Part II (4 chapters) is devoted to Dynamics and Control. The stages from modeling through control design and implementation are covered in this part, with many power electronic examples worked out to illustrate the principles and demonstrate the mechanics. The modeling and analysis aspects are distilled >from the power electronics research literature. Special attention is given to sampled-data models, as these are well matched to the cyclic fashion in which most power electronic circuits are operated. The control perspective is "neoclassical" --- i.e. classical, but drawing on modern (post-modern?!) perspectives --- and illustrated on continuous-time LTI models obtained by averaging and linearizing nonlinear switched models. The authors would welcome your comments on the book, if you happen to examine it. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Michel Gevers (gevers@auto.ucl.ac.be) Announcing a New Book ADAPTIVE OPTIMAL CONTROL : The Thinking Man's GPC by Robert R. Bitmead, Michel Gevers and Vincent Wertz Publisher : Prentice Hall International ISBN : 0-13-013277-2 Year : 1990 Price : $49.00 in the US, 6 32.95 in Europe Orders : In the US: Simon and Schuster Int. 200 Old Tappan Road New Jersey 07675 Tel: (201) 767-4990 Fax: (201) 767-5625 In Europe: Prentice Hall International 66 Wood Lane End Hemel Hempstead, Herts., HP2 4RG England Tel: (442) 231555 Fax: (442) 55618 -From the introduction- Because Adaptive Control consists of the coupling of a parameter estimator and a control law design schema, it is necessary in analysing the behaviour of an adaptive control scheme that we consider two complementary features; the effect of the identified parameter value upon the controller and hence on the closed loop performance, and the effect of the closed loop control on the parameter estimation. It is this explicit interplay between control law selection and parameter identification that is the focal point of this book and which distinguishes it from previous works, which have tended to concentrate on either the identifer or the control law and have relied to some extent on the insensitivity of one component from the effects of the other. The joint analysis of these separate effects presented here leads us to more specific design guidelines for adaptive control. The message of our work is that by appealing to robust control design theory this interplay above between on-line control design and closed-loop identification can be harnessed in such a way that the combined adaptive control/identification scheme possesses greater robustness margins than the separate designs of control law and identification algorithm would have allowed. In order not to confuse the issues with vague generalities, we carry through our analysis and study of consequences for the specific class of Adaptive (Linear Quadratic) Optimal Control algorithms rather than attempting to encompass all potential schemes at once. Our starting point for development and motivation is a particular member of this family of algorithms, the currently popular Generalized Predictive Control (GPC) method which is a practically engendered methodology based on intuitively appealing design rules which has met with considerable industrial acceptance. We use this procedure as the vehicle for our investigations and to make concrete our specific commentary concerning adaptive control algorithms. GPC is simultaneously the genesis and the butt of our derivations, the departure point and the way station, the focal point and the aberration. In fact, it is our excuse... Condensed Table of contents : 1. The Scene, the Props, the Players Introduction and Purpose A Jaundiced View of Adaptive Control History A Gedankenexample The Audience 2. Generalized Predictive Control The GPC Method of Clarke et al. Optimal Prediction and GPC Solution A Simple GPC Example Closed Loop Formulae GPC Based on a Performance Model 3. Linear Quadratic Gaussian Optimal Control The Linear Quadratic Regulation, Tracking and State Estimation Problem Optimal Filter Design with Disturbance Models LQG Controllers and Closed Loop Control Formulae Examples GPC as LQG 4. Stability and Performance Properties of Receding Horizon LQ Control Monotonicity and Stability of Receding Horizon LQ Control Stabilizing Feedback Strategies Comparative Performance of LQ Schemes Stability Properties of GPC 5. Robust LQG Design - Features for Adaptive Control A First Hint at the Adaptation/Robustness Interplay Robustness of Unity Feedback Systems LQ and KF Robustness - Return Difference Equalities Robustness of LQG Control - Loop Transfer Recovery AN LQG/LTR Example 6. Recursive Least Squares Identification in Adaptive Control Prediction Error Identification Frequency Domain Properties of the Identified Model Interplay between Control and Identification Recursive Identification in Closed Loop - Local and Global Theory 7. A Candidate Robust Adaptive Predictive Controller The Certainty Equivalence Control Law The System Parameter Identifier The Candidate - The Platform Computer Studies and Examples 8. Le Jugement Dernier Adaptation and Stability Robustness, Adaptation and Performance Forethoughts on a Postscript Candidate Alternative Control Laws and Identification Methods Refinements: The Rohrs Examples, Adaptive Control versus Robust Control Coda *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: F.E. Cellier Announcing a systematic, broad-based approach for engineers, scientists, and applied mathematicians - F. E. Cellier, University of Arizona, Tucson, AZ CONTINUOUS SYSTEM MODELING Modeling and simulation have become indispensable design tools since they permit us to predict the behavior of a system before it is actually built. In fact, modeling and simulation are the only techniques available that allow us to analyze arbitrarily nonlinear systems accurately and under varying experimental conditions. Cellier's CONTINUOUS SYSTEM MODELING introduces students to an important subclass of modeling. It deals with the modeling of systems described by a set of ordinary or partial differential equations or difference equations. Simulation will be treated in a later volume. Cellier's aim in this first book is to provide students and teachers with a unified framework for the methodology of modeling nonlinear systems described by differential and difference equations. It introduces many of the major modeling techniques and software tools which support the modeling of any continuous system. The coverage culminates by addressing the modeling of the process of modeling itself, i.e., how can this process be formulated and formalized for implementation by artificial-intelligence methods such as neural networks. Because modeling is used in many branches of the hard and soft sciences, a diversity of terminologies and application-specific jargon has proliferated. This book attempts to unify the entire area by explaining the similarities and dissimilarities between various techniques and by creating a common toolbox using a common terminology. The text has the flavor of the mathematical discipline of dynamical systems and is strongly oriented toward Newtonian physical science with the concepts of mass and energy and the laws of thermodynamics central to the discussion. It provides detailed coverage of modeling techniques such as bond graphs and system dynamics, and various software tools such as DYMOLA and STELLA. Each chapter of this senior and graduate-level text is fully complemented with a summary, references, homework problems, and suggestions for projects and research. Professor Cellier will make available a solutions manual with accompanying brief tutorial on a 5 1/4 in. diskette. CONTENTS: Preface. 1. Introduction, Scope, Definitions. 2. Basic Principles of Continuous System Modeling. 3. Principles of Passive Electrical Circuit Modeling. 4. Principles of Planar Mechanical System Modeling. 5. Hierarchical Modular Modeling of Continuous Systems. 6. Principles of Active Electrical Circuit Modeling. 7. Bond Graph Modeling. 8. Modeling Non-Equilibrium Thermodynamics. 9. Modeling Chemical Reaction Kinetics. 10. Population Dynamics Modeling. 11. System Dynamics. 12. Naive Physics. 13. Inductive Reasoning. 14. Artificial Neural Networks and Genetic Algorithms. 15. Automated Model Synthesis. 1991/755 pp., 288 illus./Hardcover/$69.50 ISBN 0-387-97502-0 CALL TOLL FREE: 1-800-SPRINGE(R) [1-800-777-4643] in NJ, 201-348-4033 [9am to 4:30pm EST] [NY, NJ, MA, and CA residents, please add sales tax. Canadian residents please add 7% GST. Prepayment required from individuals. Please add $2.50 for shipping.] Springer-Verlag New York, Inc. ATTN: Ken Quinn 175 Fifth Ave. New York, NY 10010 *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: delliott@cec2.wustl.edu (Dave Elliott) WASHINGTON UNIVERSITY Washington University seeks qualified candidates for the position of Professor and Chair of the Department of Systems Science and Mathematics, with a desired starting date of July 1, 1992. We are interested in outstanding candidates with a strong research record, with a dedication to excellence in undergraduate and graduate education and with a demonstrated potential for administration and leadership. Washington University has a longstanding commitment to the principle that all candidates should be afforded equal opportunity regardless of age, race, sex or physical disability. Candidates mus send a curriculum vitae and a list of references to: Professor C.I. Byrnes, Search Committee for the Systems Science and Mathematics Chair, Campus Box 1040, Washington University, One Brookings Drive, St. Louis, MO 63130-4899. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by Iven Mareels, Interdisciplinary Engineering Program, Australian National University. FACULTY POSITIONS AT THE AUSTRALIAN NATIONAL UNIVERSITY Senior Lecturer/Lecturer in Mechanical Engineering The Interdisciplinary Engineering Program (IEP) at the Australian National University (ANU) invites applications for a tenurable position at the senior lecturer/lecturer level. Currently there are two vacancies. A PhD in engineering, specialising in robotics and/or manufacturing is essential. The successful candidate is expected to contribute to both the undergraduate teaching and research activities. Strong links exist between the IEP and the Department of Systems Engineering in the Research School of Physical Sciences and Engineering, Institute of Advanced Studies, ANU. Both departments are members of a Corporate Research Centre in Adaptive and Robust Systems. Other partners in this centre are the Defence Science and Technology Organisation, the Commonwealth Scientific and Industrial Research Organisation and Broken Hill Propriety Ltd. The IEP has excellent computing facilities, including access to a Fujitsu parallel supercomputer, two five degrees of freedom robot arms and a CNC machining centre. The IEP is a young, dynamic program in the Australian National University with excellent funding from both university and external sources. Candidates should submit their curriculum vitae, and the names of at least three referees to The Secretary, Australian National University, GPO Box 4, Canberra ACT 2601. Further information can be obtained from Prof. D. Williamson, e-mail darrell@faceng.anu.edu.au. or phone int+61+6+2493378, (06) 249 3378. or Dr. Iven Mareels email iven@faceng.anu.edu.au THE ENGINEERING PROGRAM The Council of the Australian National University (ANU) approved in August 1989 the introduction in 1990 of the new four year undergraduate engineering degree program. This decision represented the next step in the strategic plan for the development of engineering at the ANU. Over the past ten years, four engineering departments involving over twenty-five members of academic staff have been established within the Research School of Physical Sciences and Engineering (RSPhysSE). Furthermore the engineering program is heavily involved with a Corporate Research Centre sponsored by the Commonwealth Government. The other partners are DSTO, CSIRO and BHP. The centre concentrates both applied (short term) and long term research in the area of robust signal processing and control. It facilitates links with industry and non-university based research organisations. The undergraduate engineering program is designed to integrate with the existing strengths in RSPhysSE and the Faculty of Science, and is to be responsive to major new technologies. The program provides an interdisciplinary education in special fields of engineering that are usually the province of either Electrical, Computer or Mechanical engineering, and blends core and elective material to satisfy both breadth and depth requirements. The ANU currently offers ME and PhD research degrees in Engineering. Planned developments within the graduate school may eventually allow ME degrees by course work only. FACILITIES The ANU has a large investment in engineering facilities. The following list is not exhaustive. Hypervelocity aerodynamics and shock wave laboratory; Software engineering laboratories; Workshops; electronic materials laboratories; major system simulation facilities; experimental computer architectures. The ANU also has a long tradition of significant involvement with engineering developments outside the University. Recent examples include: Design and construction of 2.3. m telescope; development of surfactant materials separation technology; optical fibres; robotics software; parallel computers; solar energy; finite element codes for simulation of solidification; contract wind tunnel testing for re-entry vehicles; grants from NASA and ESA for scram-jet and space plant developments; grants from ATERB and OTC for telecommunications research; grants >from Boeing Aircraft company for research into wing flutter suppression; grants from BHP for research into seismic signal processing for mineral exploration; grants from CSR for research into modern control methods for sugar cane mills. COMPUTING FACILITIES The Engineering Program currently operates a network of SUN workstations (UNIX 4.2) dedicated to research activities. The Department also has access to VAX 785s (VMS), FACOM 160, Pyramid (UNIX). VP100 Supercomputer and VAX 8700 operated by the Computer Services Centre. Undergraduate teaching is also supported by SUN workstations. CLOSING DATE : June 15, 1991 SALARY Will be within the range: Lecturer: A$32,197 - A$41,841 Senior Lecturer: A$42,703 - A$49,529. Salary loading may be negotiated. Appointment is on a three year probation period. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: Levent Onural OPEN RESEARCH POSITIONS IN IMAGE SEQUENCE PROCESSING -- Bilkent University (RAs, TAs, PostDocs and Assistant Professors) Our department has just received a grant for a period of four years to investigate new image coding techniques for video image compression and transmission. This includes new digital video transmission techniques as well as low bit rate transmission for videophone. Mobile video communications is also of interest. The research project will be conducted as a part of the well known European Community COST211 project. About 15 European countries are officially participating in COST211. The department is already equipped with many SUN workstations and an SR151 full option image processor. With the funds allocated from the newly acquired grant new SUN workstations and an image sequencer will be purchased and the existing image processing lab will be upgraded. We are looking for graduate students to study both for MS and Ph.D degrees. Those candidates who are already familiar with image sequence processing and coding are encouraged to apply. Teaching assistantships are also available, and joint research-teaching appointments can be made. The language of instruction is English throughout the university. Postdoctoral research positions as well as regular faculty appointments at assistant professor level are possible for Ph.D. holders. The salaries for the positions are competitive and there is a possibility of rent-free on campus housing. Please send resume and names of three references to: Dr. Levent Onural, Electrical and Electronics Engineering Department, Bilkent University, TR-06533 Ankara, Turkey. FAX: +90 4 2664127, email: onural@trbilun.bitnet Applications before June 1, 1991 will receive full consideration. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: V. Balakrishnan (ragu@isl.stanford.edu) Memo and code available: Branch and Bound Algorithm for Computing the Minimum Stability Degree of Parameter-dependent Linear Systems V. Balakrishnan, S. Boyd and S. Balemi Information Systems Lab Dept. of Elec. Engg. Stanford University Stanford CA 94305 We consider linear systems with unspecified parameters that lie between given upper and lower bounds. Except for a few special cases, the computation of many quantities of interest for such systems can be performed only through an exhaustive search in parameter space. We present a general branch and bound algorithm that implements this search in a systematic manner and apply it to computing the minimum stability degree. For hard copies of the memo as well as more detailed information on accessing the code, please send email to ragu@isl.stanford.edu. A postscript file of the memo, source code, some common binaries (sun3, sparc, DEC mips) and a small library of examples are available via anonymous ftp from rascals.stanford.edu (below /pub/msd; a compressed tar file msd_all.tar.z contains everything). The examples directory is writable; we welcome the installation of new problems. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by: J.M.MACIEJOWSKI (jmm@eng.cam.ac.uk) STANDARDS FOR CONTROL CAD SOFTWARE In 1986 IFAC set up the Working Group: `Guidelines for computer-aided control system design (CACSD) software'. Also the IEEE Control Systems Society has a Standing Committee on Standards - which has been interpreted to mean CACSD Standards. I have recently become chairman of both of these bodies, in succession to Magnus Rimvall. I would like to begin my activities by surveying the control community, to see whether there is a perceived need for such standards activity, if so where it should be concentrated, and how best it might be pursued. Feedback can be by: e-mail jmm@eng.cam.ac.uk fax +223 332662 post Dr J.M.Maciejowski Cambridge University Engineering Dept Trumpington Street Cambridge CB2 1PZ England Also, if there is sufficient interest, I propose to organise open meetings at the following two conferences: IFAC CACSD Symposium, Swansea, UK, July 1991. IEEE CDC Conference, Brighton, UK, December 1991. I would appreciate feedback from the whole community, especially those using CACSD software, as well as those writing it. Comments from outside the academic world would be particularly welcome. Here is a brief summary of what has been achieved so far, followed by my thoughts on the future: The IFAC Working Group decided to focus on 3 areas: User interfaces, Data structures, and Algorithms. The User Interfaces sub-group has been the most active. It has produced a 40 page standard for an interactive command language to be used for CACSD. It is based on Matlab, but has also been influenced by other products such as MatrixX and CTRL-C. Following this standard would allow algorithms coded in the command languages of different packages to be exchanged. The standard is nearly ready for release, which will probably be done by announcements in control journals. The Data Structures sub-group took as its initial aim the specification of control-specific data structures (eg state-space model, frequency response etc) and a standard ASCII representation for these. The idea was to allow objects such as plant models or controllers, or results of complete analyses, to be moved easily between various packages. After some initial activity we found that there is an ISO (International Standards Organisation) activity to develop a language for defining that kind of thing. We waited for this activity to stabilise, which now seems to have occurred, but we have not actually done anything more. The Algorithms sub-group has focussed on specifying the numerical algorithms needed for CACSD activity. This sub-group has not been active, but some of its members have been involved with the SLICE/NAG library, and have therefore been working towards the same ends. Are these activities still the right ones to pursue? They were in 1986, but rather a lot has changed in CACSD since then. We have rather better software products now, with PC/Pro-Matlab becoming almost a standard in some parts of the community, and we have had great technological changes in the last few years: workstations with X-windows, for instance, have removed/reduced some of the old incompatibility problems, and perhaps created new ones. In the area of Data Structures (which I know best, since I have been chairman of that sub-group) I think we have concentrated too much on the academic world: exchanging transfer functions is easy, but should we be thinking of moving Plant Instrumentation Diagrams between companies, or other activities at that level? The problem of getting the work done is a real one. The User Interface standard is the result almost entirely of one person's efforts (Magnus Rimvall's), with only a few others providing feedback and comments. In many other `voluntary' standards activities there is a commercial interest, which leads to individuals obtaining funds and time from their employers. This is not so in CACSD, with the result that the standards activity goes to the bottom of (nearly) everyone's priorities. Perhaps we need to pursue the standards activity by means of a number of contracts with commercial companies or government funding agencies. If you have a view on CACSD standards, or would like to be involved, please let me know. Since this announcement is likely to reach academics mostly, please pass it on to your industrial friends. *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** Contributed by David J. N. Limebeer MSc and PhD Courses in Control Systems at Imperial College Imperial College is a major European center for postgraduate studies and research in the control systems field, and has a leading reputation for research in several of the main areas of control systems analysis and design including system identification, adaptive control, multivariable control system design (especially H-infinity control) and process control. It offers a 12 month MSc course based on lectures and project work. It also offers a broad postgraduate research program leading to the PhD. The Control Group in Electrical Engineering has close links with the Department of Chemical Engineering, and this connection supports several industrially based projects in the process control field. Our courses will benefit graduates wishing to acquire the skills in advanced control system design demanded by many hi-tech industries. For further details (and application form), please write to: Dr. R. B. Vinter Department of Electrical Engineering Imperial College London SW7 2BT England *.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.** END OF ELETTER 41, MAY 91