IPNet Digest Volume 9, Number 04 April 30, 2002 Today's Editor: Patricia K. Lamm Michigan State University Today's Topics: Special Semester on Inverse Problems Int'l Symposium on Inverse Problems in Engineering Mechanics SIAM Conference on Optimization SIAM 50th Anniversary and 2002 Annual Meeting Table of Contents: Inverse Problems in Engineering Table of Contents: Linear Algebra and Its Applications Submissions for IPNet Digest: Mail to ipnet-digest@math.msu.edu Information about IPNet: http://www.mth.msu.edu/ipnet Mail to ipnet-request@math.msu.edu ----------------------------- From: "Prof. Heinz W. Engl" Subject: First Announcement of a Special Semester on Inverse Problems Date: Sat, 20 Apr 2002 First Announcement of a Special Semester on Inverse Problems: Computational Methods and Emerging Applications (September 8 - December 13 , 2003) at IPAM, UCLA, Los Angeles Inverse problems are problems where causes for a desired or an observed effect are to be determined. They have, nearly always driven by applications, been studied for nearly a century now. An important key feature, both theoretically and numerically, of inverse problems is their ill-posedness, i.e., they do not fulfill Hadamard´s classical requirements of existence, uniqueness and stability, under data perturbations, of a solution: Solutions of an inverse problem might not exist for all data (e.g., a consistent temperature history exists only for a very smooth final temperature in the model of the classical heat equation), it might not be unique (which raises the practically relevant question of identifiability, i.e., the question if the data contain enough information to determine the desired quantity), and it might be unstable with respect to data perturbations. The last aspect is of course especially important, since in real-world problems, measurements always contain noise (another source of noise being errors in numerical procedures), and approximation methods for solving inverse problems which are as insensitive to noise as possible have to be constructed, so-called regularization methods. In the last twenty years, the field of inverse problems has undergone rapid development: The enormous increase in computing power and the development of powerful numerical methods made it possible to simulate real-world direct problems of growing complexity. Since in many applications in science and engineering, the inverse question of determining causes for desired or observed effects is really the final question, this lead to a growing appetite in applications for posing and solving inverse problems, which in turn stimulated mathematical research e.g., on uniqueness questions and on developing stable and efficient numerical methods (regularization methods) for solving inverse problems. This began mainly for linear problems, but more recently it has also been done for nonlinear problems. The Special Semester at IPAM will focus on new challenges that have appeared recently in the field of inverse problems: 1.) New application fields: - Imaging Science including Image Processing, Computer Graphics and Computer Vision. Many imaging problems are by their nature inverse problems, which suggests the use of regularization methods for their solution. On the other hand, specific methods developed in imaging like bounded-variation-regularization and diffusion filtering are being applied to other inverse problems. From the applications side e.g. in medical imaging, new techniques are emerging like elastographics and optical tomography, which in turn pose new mathematical and computational questions. - Inverse problems in life sciences: Life sciences are a real growth field for mathematical modeling. An important step in modeling is to determine parameters from measurements. In life sciences, this usually leads to large-scale inverse problems, e.g., the simultaneous determination of hundreds of rate constants in very large reaction diffusion systems. Other, already a bit more classical, inverse problems in life sciences include inverse folding problems. Since many mathematical models in the life sciences are just now being developed, this will be the right time to bring experts in life sciences who develop such models and experts on inverse problems together in a kind of exploratory workshop. - Inverse problems in industry: Knowledge about mathematical and numerical methods for inverse problems has diffused faster into the scientific community than into industry. On the other hand, many mathematical problems of interest to industry are in essence inverse problems. At the IPAM Special Semester, such problems will be studied and worked on in a "study group" format. - Inverse problems in physical sciences: Many measurements in the physical sciences are indirect, thus their interpretation is an inverse problem whose ill-posedness is not always appropriately addressed. An example are deconvolution problems for ground based telescopes; deconvolution also appears in many other applications like in spectroscopy or in the interpretation of time-resolved fluorescence data with a variety of applications in medicine and biology. Also, modelling of epitaxial growth or other growth processes involves various inverse problems like the determination of growth rates from measured data or shape optimization problems; a methodological link to inverse problems is the use of level set methods. 2.) Methodological challenges - In recent years, extremely powerful numerical methods have been developed for solving complex direct problems, e.g., multi-field problems in three dimension, both static and dynamic. Such methods include multigrid or, more general, multi-level methods and domain decomposition. When solving inverse problems for such complex problems, new questions arise also for the numerical treatment of the inverse problem, which include the optimal coupling of regularization methods with direct solvers in order to achieve overall optimal performance - A powerful numerical method whose main advantage is that it can easily handle changes in the topology is the level set method. It has recently also been applied to inverse problems. - Over the years, two major approaches have been followed in the inverse problems community: statistical and functional-analysis based approaches. A full understanding of the relations between these approaches is still lacking; this is also important for the issue of "uncertainty". During the proposed Special Semester, special emphasis will be laid on some of these and other emerging challenges, although more classical topics will not be neglected. The Special Semester is intended to bring together scientists and engineers with applied and pure mathematicians interested in inverse problems. The Special Semester will be structured as follows: 1.) Tutorials: In the second (and maybe also third) week of September 2003, a series of tutorials will be held both on methodological and on applications issues of inverse problems. These should also set the stage for research collaborations between mathematicians and applications scientists that should go on throughout the semester, and should prepare the participants for the subsequent events. The final list of topics has not yet been decided, a tentative list is: - methodology: regularization methods for inverse problems inverse spectral problems statistical and wavelet methods for inverse problems level set methods - application fields inverse problems in the physical sciences, grouped according to different application fields inverse problems in imaging science inverse problems in biology inverse scattering and tomography 2.) Study group with industry: This format has probably the longest tradition in Oxford and has been implemented also in other European countries, in Australia, and at RPI. On the first day of such a study group, industrial researchers present problems for which they want a mathematical model, solution, algorithm. In the following days, open discussions in groups, which tend to be quite intensive, should lead to progress. The outcome will generally not be a final solution, but a first mathematical model and a clear plan for further work. Such a study group should focus on problems from West Coast industries (but not exclusively) in order to make a follow-up by inverse problems experts who visit IPAM for the semester possible. Topics where industrial contacts have already been made include inverse problems and optimal design in photonics and inverse problems in finance, especially identification of volatilities and interest rate models. 3.) Workshops: As a central part of the Special Semester, will be several workshops distributed over the whole semester focussing on the emerging challenges mentioned above. The workshops will be organized in two series in such a way that participants who are interested in two related topics can attend two consecutive workshops; the dates of these workshops have not yet been decided. WORKSHOP SERIES 1: Computational Methods - Level Sets - Growth Processes WORKSHOP SERIES 2: Deconvolution and Related Inverse Problems in the Physical Sciences - Emerging Applications of Inverse Problems Techniques to Imaging Science - Inverse Problems in the Life Sciences 4.) Wrap-Up Meeting at Lake Arrowhead: The Special Semester will close with a meeting in mid December at Lake Arrowhead, which will focus on reports of the progress made by senior and junior long-term participants. Although these events form the core of the proposed Special Semester, there will also be ongoing activities throughout the semester by visitors interacting on specific research problems with colleagues at UCLA and neighboring universities and with each other. In due course, a call for applications for long-term participants will be made, but tentative expressions of interest are already welcome now. The Chair of the Program Committee is Prof. Heinz W. Engl (Industrial Mathematics Institute, Johannes Kepler Universität Linz, Austria). He would welcome suggestions concerning topics and participants for the workshops, contacts to industry for study group problems, and expressions of interest for long-term participation at the Special Semester: engl@indmath.uni-linz.ac.at Submitted by: Prof.Dr.Heinz W. Engl E-Mail: engl@indmath.uni-linz.ac.at Institut fuer Industriemathematik secretary: nikolaus@indmath.uni-linz.ac.at Johannes-Kepler-Universitaet Phone:+43-(0)732-2468...,ext.9219 or 8693, Altenbergerstrasse 69 secretary: ext.9220 A-4040 Linz Fax:ext. 8855 Oesterreich / Austria home phone: +43-(0)732-245518 Mobile Phone: +43-(0)664-5209209 Mobile Fax: +43-(0)664-5274338 World Wide Web: http://www.indmath.uni-linz.ac.at/ ----------------------------- From: Masataka Tanaka Subject: Int'l Symposium on Inverse Problems in Engineering Mechanics Date: Thu, 18 Apr 2002 ISIP2003 International Symposium on Inverse Problems in Engineering Mechanics, 18-21 February 2003 Nagano/Japan A first announcement of the above international symposium ISIP2003 is now available, and disclosed at the URL: http://homer.shinshu-u.ac.jp/ISIP2003/ The subject of the Symposium is a wide range of inverse problems in engineering mechanics: mathematical and computational aspects, parameter or system identification, shape determination, sensitivity analysis, optimization, material property characterization, ultrasonic NDT, other topics related to electromagnetics, elastodynamics, thermal or fluid engineering. Submission of your paper and/or participation in the Symposium will be heartily welcome. The important dates for paper submission are as follows: 1. Deadline for abstract within two pages of A4 sheet: October 15, 2002 2. Notification of acceptance: December 17, 2002 3. Deadline for final camera-ready manuscript of full paper: February 18, 2003 4. Symposium: February 18-21, 2003 All the communications for the Symposium including paper submission and also paper review will be made through the Internet. Symposium Chair: Prof. Masataka Tanaka Department of Mechanical Systems Engineering Shinshu University 4-17-1 Wakasato, Nagano, 380-8553 Japan E-mail: dtanaka@gipwc.shinshu-u.ac.jp ----------------------------- From: ross@siam.org Subject: SIAM Conference on Optimization Date: Mon, 01 Apr 2002 The SIAM Conference on Optimization in Toronto, Canada is almost here! May 20-22, 2002 are the conference dates with Short Courses on May 19 and the Validated Computing Workshop from May 23-25. The Preregistration Deadline date (April 16, 2002) for your hotel and SIAM registration is rapidly approaching! Register NOW with the hotel and benefit from the SIAM room rate of only $146.00 USD! Register NOW with SIAM and save $60.00 USD off of your conference registration! April 16, 2002 is the Deadline and rapidly approaching. Westin Harbour Castle Hotel 1 Harbour Square Toronto, Ontario M5J 1A6, Canada Direct Telephone: 416-869-1600 Fax Reservation: 416-361-7448 Toll Free: 800-WESTIN-1 (US and Canada Only) www.westin.com SIAM Optimization Conference Webpage: http://www.siam.org/meetings/op02/ ----------------------------- From: cyoung@siam.org Sender: cyoung@siam.org To: ipnet Subject: SIAM 50th Anniversary and 2002 Annual Meeting Date: Fri, 19 Apr 2002 SIAM 50th Anniversary and 2002 Annual Meeting Philadelphia Marriott Hotel, Philadelphia, PA July 8-12, 2002 Program Schedule is now available. Please visit: http://www.siam.org/meetings/SIAM50 Hotel reservation and pre-registration deadline: June 6, 2002 For additional information, contact SIAM Conference Department at siam@meetings.org ----------------------------- From: "James Beck" To: ipnet Subject: Table of Contents, Inverse Problems in Engineering Date: Mon, 29 Apr 2002 Inverse Problems in Engineering February 2002 Vol. 10, No. 1 Table of Contents Mobile HVAC System Evaporator Optimization and Cooling Capacity Estimation by Means of Inverse Problem Solution A. V. Moultanovsky Inverse Heat Conduction Problem Approach to Identify the Thermal Characteristics of Super-Hard Synthetic Materials A. V. Moultanovsky and M. Rekada A Modal Approach to Solve Inverse Heat Conduction Problems J.-L. Battaglia Design of Two-Phase Displacement Experiments A. Sylte, E. Ebeltoft, A.-A. Grimstad, R. Kulkarni, J.-E. Nordtvedt, and A. T. Watson Estimation of Thermal Contact Resistance Between the Materials of Double-Layer Sample Using the Laser Flash Method N. D. Milosevic, M. Raynaud, and K. D. Maglic ----------------------------- From: Hans Schneider To: ipnet Subject: LAA contents Date: Sun, 7 Apr 2002 Linear Algebra and its Applications May 2002 Vol. 347, Issues 1-3 Table of Contents Decomposition of matrices into commutators of involutions Baodong Zheng A conjecture on the second largest eigenvalue of a tree with perfect matchings Ji-Ming Guo and Shang-Wang Tan The distance matrix eigensystem of an equally spaced row of points Kenneth W. Holladay Parameter depending state space descriptions of index-2-matrix polynomials Martin Bracke, Sven Feldmann and Dieter Pratzel-Wolters On tangent spaces and external flats to Grassmannians of lines over finite fields Antonio Cossidente and Alessandro Siciliano A characterization of commutators of idempotents Roman Drnovek, Heydar Radjavi and Peter Rosenthal An application of the Grobner basis in computation for the minimal polynomials and inverses of block circulant matrices Shenggui Zhang, Zhaolin Jiang and Sanyang Liu Orthogonality of matrices Chi-Kwong Li and Hans Schneider A sharp upper bound on the largest eigenvalue of the Laplacian matrix of a graph Jin-Long Shu, Yuan Hong and Kai Wen-Ren Signed frames and Hadamard products of Gram matrices Irine Peng and Shayne Waldron An analysis of completely-positive trace-preserving maps on Mary Beth Ruskai, Stanislaw Szarek and Elisabeth Werner On g-inverses of a bordered matrix: revisited Musheng Wei and Wenbin Guo Point equation of the boundary of the numerical range of a matrix polynomial Mao-Ting Chien, Hiroshi Nakazato and Panayiotis Psarrakos Birkhoff's theorem and convex hulls of Coxeter groups Nicholas McCarthy, David Ogilvie, Ilya Spitkovsky and Nahum Zobin Generalizations of the field of values useful in the study of polynomial functions of a matrix Anne Greenbaum Spectral distribution of generalized Kac-Murdock-Szego matrices William F. Trench Automorphisms of tiled orders Jeremy Haefner and Christopher J. Pappacena Multiplicative mappings of operator algebras Fangyan Lu Submitted by: Hans Schneider hans@math.wisc.edu. Department of Mathematics 608-262-1402 (Work) Van Vleck Hall 608-271-7252 (Home) 480 Lincoln Drive 608-263-8891 (Work FAX) University of Wisconsin-Madison No Home FAX at present Madison WI 53706 USA http://www.math.wisc.edu/~hans (URL) ------- end -------