IPNet Digest Volume 1, Number 01 January 19, 1994 Today's Editor: Patricia K. Lamm Michigan State University Today's Topics: IPNet Membership An Ill-Conditioned Circuits Problem GAMM-SIAM Conference on Inverse Problems Conference on Dynamic System Identification & Inverse Problems Inverse Problems in Engineering Seminar Table of Contents: LINEAR ALGEBRA AND ITS APPLICATIONS Submissions for IPNet Digest: Mail to ipnet-digest@math.msu.edu Information about IPNet: Mail to ipnet-request@math.msu.edu ------------------------------ From: ipnet-digest@math.msu.edu Subject: IPNet Membership Date: Wed, 19 Jan 1994 In the first 2 weeks of its existence, the IPNet has subscribed around 150 members. To obtain a list of current subscribers and their e-mail addresses, send a message to 'ipnet-request@math.msu.edu' with the following in the body of the message: who The subject line of the message is ignored. All submissions to the IPNet Digest are encouraged. Send news items via e-mail to 'ipnet-digest@math.msu.edu' for consideration in the next issue. ------------------------------ From: wiedmann@ihf.uni-stuttgart.de (Frank Wiedmann) Subject: An Ill-Conditioned Circuits Problem Date: Tue, 11 Jan 1994 I am an EE student presently working on my final project. The problem I have to solve is to calculate the currents in an electric circuit from the electro-magnetic fields measured above the circuit. The way I am dealing with this at the moment is the following: The circuit is modeled as a rectangular wire grid with constant currents assumed in each section of the grid. The fields above the grid caused by these currents are then calculated yielding a matrix mapping the currents in the different sections of the grid to the fields at the various points above the grid. Then the (generalized) inverse of this matrix is calculated using singular value decomposition (SVD) giving a matrix that maps the measured fields to the currents. Due to the comparatively bad condition of the matrix and to errors in the measured data, regularization has to be used. Presently this is being done by setting the lower singular values to zero when calculating the generalized inverse until the result "looks good" (at the moment I have very little information on the amount of error in the measured data). The results I am getting this way look acceptable from a qualitative point of view, if they are really good quantitatively has not been checked yet. I would like to hear comments (alternative/superior methods, problems that might occur, etc.) from others that have already dealt with this kind of problem, as I think that it should be a fairly common one. I am also interested in good books on the subject (SVD, generalized inverse, regularization, etc.). Thank you very much for your time, Frank Wiedmann E-Mail: wiedmann@ihf.uni-stuttgart.de ------------------------------ From: "PROF.HEINZ W. ENGL" Subject: GAMM-SIAM Conference on Inverse Problems Date: Tue, 11 Jan 1994 GAMM-SIAM Conference on "Inverse Problems in Diffusion Processes" St.Wolfgang, Austria June 27 - July 1, 1994 First Announcement This conference is the first one in a series of conferences on different application fields of inverse problems. The organizing committee for this series consists of David Colton (Newark, DE, USA), Heinz W. Engl (Linz, Austria), Alfred Louis (Saarbr|cken, Germany), and William Rundell (College Station, TX, USA). In addition, there is an advisory committee consisting of M.Bertero, G.Chavent, M.Cheney, R.Ewing, A.Friedman, R.Kre_, K.Kunisch, P.Sabatier, and W.Symes. The first conference is organized locally by Heinz W. Engl and focusses on inverse problems as they appear in the mathematical formulation of diffusion processes, both transient (parabolic pde's) and steady-state (elliptic pde's). This includes parameter identification problems and problems involving side conditions that render them ill-posed. Besides questions of uniqueness and stability, numerical algorithms and applications in science and technology are of special interest. The following invited speakers have so far confirmed their presence at least tentatively: A.Bakushinskii, J.Beck, G.Crosta, L.Elden, A.Friedman, Hong-Ming Yin, V.Isakov, K.Kunisch, A.Lorenzi, B.Lowe, D.Ross, T.Seidman, D.Tataru, G.Vainikko, S.Vessella, and K.Zeman. In addition to invited talks, there will also be the possibility of some contributed talks of 30 minutes (including discussion) fitting into the scope of the meeting. Participants who wish to give a talk should indicate below and include an abstract. Since we want to avoid parallel sessions, we also encourage participation at this conference just by being there and taking part in the discussions! The meeting will be held in a conference center on Lake St.Wolfgang in one of the most picturesque parts of the Austrian Alps. Because of space limitations, the meeting will be open to up to 120 participants. Therefore, we suggest early registration! The most convenient airport (and train station) is Salzburg, Austria. Salzburg has good flight connections to major gateway airports in central Europe and good train connections to Munich and Vienna. Since June/July is high tourist season, early flight bookings are advised. However, please do not make a firm booking before you hear from us! Detailed travel information from Salzburg onwards will be sent in a second announcement. Participants should arrive at the conference center on June 26 and leave on July 2. The total price for accommodation and full board for this period is currently 4000 Schilling (minor changes possible; currently, 7.15 Schilling = 1 DM, 11 Schilling = 1 US$). Accommodation for accompanying persons is very limited in the conference center, but double rooms in hotels can be booked if we know early enough (at different prices depending on the category). There will be a conference fee of up to 1400 Schilling. This also includes an excursion on Wednesday afternoon (price for accompanying persons: 250 Schilling). If our funding applications are successful, this conference fee might be substantially smaller. The exact amount will not be known until a few weeks before the meeting. In addition to this possible reduction of the conference fee, financial support for participants other than invited speakers is not available. If you want to participate in this meeting, please ask for the registration form as soon as possible; technically, the registration deadline is January 21, 1994, but registrations which are a little bit late can still be accepted. Contact me either by Fax at +43-732-2468855 or by E-Mail: engl@indmath.uni-linz.ac.at Prof.Dr.Heinz W. Engl ------------------------------ From: beck@egr.msu.edu (Dr. James Beck) Subject: Conference on Dynamic System Identification, Inverse Problems Date: Wed, 19 Jan 94 Second International Conference DYNAMIC SYSTEM IDENTIFICATION and INVERSE PROBLEMS St.Peterburg, Russia 22 - 25 August 1994 Organized by: Moscow Aviation Institute, International Center for Advanced Studies "Cosmos", Scientific Council on Thermal Problem in Technology of Russian Academy of Sciences Objectives: Identification problems of Thermodynamics, Mechanical, Fluid Mechanical, Electrical, and Nuclear System in industry (which are usually of a very complex nature, involving different types of mechanisms, nonlinearities, phase change and other phenomena) is a very important branch of engineering science at present. Following the successful first conference in this series, held in Suzdal, Russia, in 1990, the aim of this second international conference on Dynamic System Identification and Inverse Problems is to discuss the type of inverse problems and optimal experiment design problems which occur in engineering practice. The behaviour of numerical methods in these extreme conditions will be investigated and the methods critically evaluated by comparison with experiments or established benchmarks wherever possible. The conference is of importance to all scientists and engineers who are actively involved in developing an innovative approach as well as in solving industrial problems. Methods of interest include all efficient numerical techniques being applied to cope with a wide variety of identifications problems. The International scientific advisory committee members anticipate that the conference will point out new directions in identification of mathematical models of dynamic processes. Conference Themes: The topics below give a guideline for possible inverse problems contributions. Papers on other related topics will also be accepted if they fall within the objectives of the conference. Heat Conduction Thermal Stability Thermal Radiation Vibration Diffusion-Convection Acoustics Thermal Processes in Porous Media Materials Processing Thermal Processes in Composites Elasticity and Elasto-Plasticity Phase Change Processes Tomography Fire and Combustion Gas-Liquid Flows Nuclear Transport International scientific advisory committee: Chairman: Prof. O.M. Alifanov Moscow Aviation Institute, Russia Prof. J.V. Beck Michigan State University, USA Prof. A.F. Emery University of Washington, USA Prof. J.P. Bardon ISITEM, University of Nantes, France Prof. Y.M. Matseevity Institute for Problems in Machinery, Kharkov, Ukraine Prof. V.A. Morozov Moscow State University, Russia Executive committee: Dr. A.V. Nenarokomov Moscow Aviation Institute Mr. S.A. Budnik ICAS "COSMOS" Dr. N.V. Kerov Moscow Aviation Institute Dr. V.V. Michailov Moscow Aviation Institute Mini-Exhibition There will be a small table-top exhibition of publications, hardware and software relevant to the conference themes. For more information please express your interest on the attached enquiry form. Call for papers Papers are invited on the topics outlined above and other topics which will fit within the general scope of the Conference. Abstracts of no more than 300 words should be submitted to the Conference Secretariat at the above fax, telex or E-mail adresses by February 1, 1994. Abstracts should clearly state the purpose, results and conclusions of the work to be described in the final paper. Time Schedule Return reply form: As soon as possible Submit abstract (300 words): February 1, 1994 Preliminary acceptance: February 1, 1994 Submit final Paper: April 1, 1994 Final acceptance: April 20, 1994 Enquiry Form: Identification of Dynamic Systems and Inverse Problems 22 - 25 August 1994, St.Peterburg, Russia Title......................Initials.............................. Surname.......................................................... Organization..................................................... Address........................................................... Tel.............................................................. Fax.............................................................. EMail............................................................ # I intend to participate in the Conference # I intend to submit a paper to the Conference # An abstract (300 words) is attached # I am interested in the mini-exhibition facilities. I suggest that this announcement may also be sent to: Title and name___________________________________________ Address___________________________________________________________ Please return the completed Enquiry form by Fax, Telex or EMail to: E.V. Filatova, Conference Secretariat Tel.#: 7(095) 158-47-56 Moscow Aviation Institute Fax : 7(095) 229-32-37 Dept. of Space System Engineering Telex: 411746 Sokol SU 4, Volokolamskoe Sh., Email: COSMOS@SOVAMSU.SOVUSA.COM Moscow, 125871, Russia ------------------------------ From: kwoodbur@kepler.me.ua.edu (Keith Woodbury) Subject: Inverse Problems in Engineering Seminar Date: Tue, 18 Jan 94 The Sixth INVERSE PROBLEMS IN ENGINEERING SEMINAR Monday, June 13 - Tuesday, June 14, 1994 and THEORETICAL AND COMPUTATIONAL ASPECTS OF ILL-POSED PROBLEMS WORKSHOP Saturday June 11 - Sunday June 12, 1994 Cincinnati, OH 45221-0025 CALL FOR PAPERS The Sixth Inverse Problems in Engineering Seminar is being organized by the Department of Mathematical Sciences at the University of Cincinnati. This event is the continuation of the informal seminars which were initiated at Michigan State University in 1987. This seminar will be sponsored by the McMicken College of Arts and Sciences, C.P. Taft Memorial Fund, Office of Vice President for Research and University Dean of Advanced Studies, and the Department of Mathematical Sciences at the University of Cincinnati. Papers are solicited from all areas involving inverse methods and their applications. Four broad categories are being used to organize sessions. These categories, with some subtopics delineated, are: 1. Inverse Problems in Heat Transfer * Inverse Heat Conduction * Thermal Property Estimation 2. Mathematical Aspects of and Techniques for Inverse Problems * Inverse Theory and Methods * Stability Considerations 3. Design of Experiments and Applications of Inverse Methods * Optimal Experiment Design * Analysis of Actual Experimental Data 4. Inverse Problems Exclusive of Heat Transfer * Bio-Engineering Inverse Problems * Shape Optimization * Inversion of Inferometric Data * Inverse Scattering and Tomography{space.1} Presentations will be informal twenty minute talks, supported by transparencies or slides, and followed by discussion. If the number of submissions warrants additional program time, a poster session will be included. Please submit a tentative TITLE and an ABSTRACT BY FEBRUARY 15, 1994. The seminar fee is $50. The Theoretical and Computational Aspects of Ill-Posed Problems Workshop is being planned in conjunction with this year's seminar. This workshop is planned primarily for graduate students in Engineering and the Sciences and will consist of three 2 hour presentations followed by open discussions. Talks will cover the mathematics and the numerical implementation of several algorithms including: Tikhonov Method, Iterate Conjugate Method, Future Times Function Specification Method, and the Mollification Method. The Workshop Fee is $25. Send titles and abstracts or other inquiries to either: Chairman: Prof. Diego Murio Phone:(513)556-4088 University of Cincinnati FAX: (513)556-3417 Department of Mathematical Sciences email: diego@dmurio.csm.uc.edu Mail Location 25 Cincinnati, OH 45221-0025 Co-Chair: Dr. Keith A. Woodbury Phone: (205) 348-1647 The University of Alabama FAX: (205) 348-6419 Department of Mechanical Engineering email: woodbury@me.ua.edu Box 870276 Tuscaloosa, AL 35487-0276 ------------------------------ From: Richard Brualdi Subject: Table of Contents: LINEAR ALGEBRA AND ITS APPLICATIONS Date: Tue, 11 Jan 1994 LINEAR ALGEBRA AND ITS APPLICATIONS Contents Volumes 197, 198 Proceedings of the Second Conference of the International Linear Algebra Society (Lisbon, 1992) Preface 1 Peter Lancaster (Calgary, Alberta, Canada), Alexander S. Markus (Beer Sheva, Israel), and Qiang Ye (Winnipeg, Manitoba, Canada) Low Rank Perturbations of Strongly Definitizable Transformations and Matrix Polynomials 3 Dragomir Z. Dokovic (Waterloo, Ontario, Canada) and Chi-Kwong Li (Williamsburg, Virginia) Overgroups of Some Classical Linear Groups With Applications to Linear Preserver Problems 31 M. J. C. Gover (Bradford, West Yorkshire, England) The Eigenproblem of a Tridiagonal 2-Toeplitz Matrix 63 Alexander Kovacec and Ana Paula Santana (Coimbra, Portugal) A Combinatorial Theorem on the Cartan Invariants of the Schur Algebra S(B+) 79 B. Beckermann and G. Muhlbach (Hannover, Germany) A General Determinantal Identity of Sylvester Type and Some Applications 93 Tsuyoshi Ando (Sapporo, Japan) and Fumio Hiai (Mito, Ibaraki, Japan) Log Majorization and Complementary Golden-Thompson Type Inequalities 113 M. Gasca and J. M. Pena (Zaragoza, Spain) A Test for Strict Sign-Regularity 133 Russell Merris (Hayward, California) Laplacian Matrices of Graphs: A Survey 143 Maria Antonia Duffner (Lisboa, Portugal) and G. N. de Oliveira (Coimbra, Portugal) Pairs of Matrices Satisfying Certain Polynomial Identities 177 Raphael Loewy and Nizar Radwan (Haifa, Israel) Spaces of Symmetric Matrices of Bounded Rank 189 Kurt J. Reinschke (Dresden, Deutschland) Graph-Theoretic Approach to Symbolic Analysis of Linear Descriptor Systems 217 Rajendra Bhatia (New Delhi, India) Matrix Factorizations and Their Perturbations 245 Joao Filipe Queiro (Coimbra, Portugal) An Inverse Problem for Singular Values and the Jacobian of the Elementary Symmetric Functions 277 Axel Ruhe (Goteborg, Sweden) Rational Krylov Algorithms for Nonsymmetric Eigenvalue Problems. II. Matrix Pairs 283 A. Bjorck (Linkoping, Sweden) Numerics of Gram-Schmidt Orthogonalization 297 Chi-Kwong Li (Williamsburg, Virginia) and Maria Emilia Miranda (Coimbra, Portugal) Antidiagonals of Matrices in a Unitary Similarity Orbit 317 Miroslav Fiedler (Praha, Czech Republic) Elliptic Matrices With Zero Diagonal 337 Eduardo Marques de Sa (Coimbra, Portugal) Faces and Traces of the Unit Ball of a Symmetric Gauge Function 349 R. B. Bapat and A. K. Lal (New Delhi, India) Inequalities for the q-Permanent 397 Natalia Bebiano, Alexander Kovacec, and Joao da Providencia (Coimbra, Portugal) The Validity of the Marcus-de Oliveira Conjecture for the Essentially Hermitian Matrices 411 Eduardo Marques de Sa (Coimbra, Portugal) Exposed Faces and Duality for Symmetric and Unitarily Invariant Norms 429 Eduardo Marques de Sa (Coimbra, Portugal) Faces of the Unit Ball of a Unitarily Invariant Norm 451 M. C. Gouveia (Coimbra, Portugal) Group and Moore-Penrose Invertibility of Bezoutians 495 J. J. McDonald (Madison, Wisconsin) A Product Index Theorem With Applications to Splittings of M-matrices 511 Daniel Alpay (Beer-Sheva, Israel), Joseph A. Ball (Blacksburg, Virginia), Israel Gohberg (Tel-Avev, Israel), and Leiba Rodman (Williamsburg, Virginia) J-Unitary Preserving Automorphisms of Rational Matrix Functions: State Space Theory, Interpolation, and Factorization 531 M. Antonia Duffner (Lisboa, Portugal) Linear Transformations That Preserve Immanants 567 Ma Asuncion Beitia and Ion Zaballa (Vitoria-Gasteiz, Spain) Invariants of the Block Tensor Product 589 Georg Heinig and Frank Hellinger (Leipzig, Germany) Displacement Structure of Pseudoinverses 623 H. Bart (Rotterdam, the Netherlands) and V. E. Tsekanovskii (Buffalo, New York) Complementary Schur Complements 651 Gordon James (London, England) Hecke Algebras and Immanants 659 Thomas J. Laffey and Robert Reams (Dublin, Ireland) Integral Similarity and Commutators of Integral Matrices 671 Jiang Erxiong (Shanghai, China) Bounds for the Smallest Singular Value of a Jordan Block With an Application to Eigenvalue Perturbation 691 Fernando C. Silva (Lisboa, Portugal) On the Number of Invariant Polynomials of Partially Prescribed Matrices 709 Biswa Nath Datta (DeKalb, Illinois) Linear and Numerical Linear Algebra in Control Theory: Some Research Problems 755 J. A. Dias da Silva (Lisboa, Portugal) REPORT: Second Conference of the International Linear Algebra Society (Lisbon, 1992) 793 Author Index 847 ------- end -------