Subject: NA Digest, V. 92, # 11 NA Digest Sunday, March 15, 1992 Volume 92 : Issue 11 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: Change of Address for Cleve Moler New Address for Siamak Hassanzadeh Address Change for C. A. de Moura Bracewell on the Hartley Transform Errata for Strikwerda's Textbook Conference on Applications of Dynamical Systems Short Course on Numerical Optimization and Software Scalable High Performance Computing Conference IMA Workshop on Linear Algebra for Signal Processing Visiting Positions at RIACS Contents: Linear Algebra and its Applications Submissions for NA Digest: Mail to na.digest@na-net.ornl.gov. Information about NA-NET: Mail to na.help@na-net.ornl.gov. ------------------------------------------------------- From: Cleve Moler Date: Sun Mar 15 06:21:03 PST 1992 Subject: Change of Address for Cleve Moler For the past two and a half years, I've been commuting between my home in California and the MathWorks main office outside Boston. This week, I cut 2700 miles off that commute by moving to Massachusetts. So, my business mailing address is now: Cleve Moler The MathWorks, Inc. 24 Prime Park Way Natick, MA 01760 The telephone number for the MathWorks switchboard is: 508-653-1415. (That's 508-65-pi). You can reach my office phone directly by dialing 508-653-2452 and then keying in extension 325. My e-mail address remains moler@mathworks.com. Our family's new home is in Sherborn, which is just south of Natick and Framingham and a few miles west of Wellesey. The mailing address is: 62 Russett Hill Road, Sherborn, MA 01770. If you're in the Boston area, and would like to visit the MathWorks, let me know -- we'd be happy to see you. -- Cleve ------------------------------ From: Siamak Hassanzadeh Date: Mon, 9 Mar 92 10:04:04-1795 Subject: New Address for Siamak Hassanzadeh Effective immediately my address is Siamak Hassanzadeh Fujitsu America, Inc. 3055 Orchard Dr. San Jose, CA 95134-2022 Phone: 408-456-7308 email: siamak@fai.com I will be working in the Computational Research Division of Fujitsu. I look forward to continuing interaction with computational community. ------------------------------ From: Carlos de Moura Date: Thu, 12 Mar 92 16:49:17 GMT Subject: Address Change for C. A. de Moura For March to August 1992 I will be working with the Group de Calcul Parallele Laboratoire de Physique Corpusculaire College de France 11, Place M. Berthelot 75231 Paris 05 Cedex FRANCE email: demoura@cdfvax.in2p3.fr Best Regards Carlos A de Moura ------------------------------ From: Gene Golub Date: Thu, 12 Mar 92 10:59:08 GMT Subject: Bracewell on the Hartley Transform The Hartley Transform R.N. Bracewell (Stanford EE370 Seminar for March 12, 1992) Spectral analysis is usually done with the aid of the Fourier transform, which is based on ideas inherited from the time of Fourier and makes full use of the mathematical theory of complex analysis which, to a large extent, developed in the last century in response to the need to resolve tricky problems of integration and convergence thrown up by exploration of Fourier's theorem. As students, we become familiar with the algebraic manipulation of complex quantities and equations such as V=ZI become second nature to us; it is true that when we come to evaluate ZI four multiplies are involved. In the days of slide rules this factor four was very noticeable and although it is less noticeable today, still, somewhere deep inside your calculator, four multiplies are performed whenever two complex numbers are multiplied together. When numerical Fourier analysis is performed complex operations are required because the Fourier spectrum of a real waveform is necessarily complex. Conversely, when we invert the Fourier transform we must have an algorithm that accepts complex input. Thus, in the first case (real data) a lot of unnecessary operations are carried out on an imaginary part that is zero-valued, while in the second case (complex input) a lot of output values are computed which are zero (or should be, to the limits of machine precision). These elementary observations tell us that there should be a way of performing spectral analysis of real data that avoids the wastefulness of a transform that must be prepared for complex input, whereas most of the time either our data are real, or our output is real. This transform is the Hartley transform; it represents a waveform with N sample values by N transform values which are real (see "Assessing the Hartley Transform," IEEE Trans ASSP, vol. 38, 2174-2176, Dec 1990 and references provided). Of course the Hartley transform graph is not the same as the Fourier transform graph, which means that some of our intuition is lost. On the other hand when we graph Fourier transforms we do not always plot both the real and imaginary parts, which are not particularly clear to grasp and which in fact change drastically for the same waveform if one only changes the choice of origin of time. Usually we graph the power spectrum, which is real and does not call on us to visualize the full complex transform. The Hartley power spectrum is the same as the Fourier power spectrum; likewise the Hartley phase is the same as the Fourier phase (with a 45 degree shift). Also it is easy to learn how to see the real and imaginary parts of the Fourier transform, given the Hartley transform, if you really want them. In summary, it seems that we will continue to retain the advantage that we get from fluency in complex algebra by using Fourier transforms in theoretical work but that when we talk to computers which prefer real numbers we will shift to the Hartley transform. By computing with real numbers we gain a factor of two in speed in the inner loops of the algorithms. This can be very important in new programming; however, if you have canned code that runs it is usually not advised to tamper with it. Interesting questions have been raised about the physical significance of the Hartley transform relative to the Fourier transform. After all, Lord Kelvin told us that "Fourier's theorem is not only one of the most beautiful results of modern analysis, but it may be said to furnish an indispensable instrument in the treatment of nearly every recondite question in modern physics." If you have the opportunity to think about the Hartley transform in advance you might like to consider whether the Fourier transform is more fundamental physically. ------------------------------ From: John Strikwerda Date: Fri, 13 Mar 92 13:53:31 -0600 Subject: Errata for Strikwerda's Textbook I have made an errata list for my textbook available by anonymous ftp. The text is: Finite Difference Schemes and Partial Differential Equations published by Wadsworth & Brooks/Cole. The errata are on the file pub/strik.errata.dvi on the computer lemon.cs.wisc.edu John Strikwerda strik@cs.wisc.edu ------------------------------ From: Tina Flores Date: Tue, 10 Mar 92 16:55:51 EST Subject: Conference on Applications of Dynamical Systems SIAM Conference on Applications of Dynamical Systems, October 15-19, 1992, Salt Lake City, UT The organizers for the conference are pleased to inform you that the DEADLINE for submitting contributed abstracts has been EXTENDED to MARCH 20, 1992. For those of you who have not yet submitted your 100-word abstract, send it NOW -- by e-mail to: meetings@siam.org by fax to: 215-386-7999 or call the SIAM office at 215-382-9800 if you have any questions. SIAM encourages electronic submission of abstracts. To help in formatting your submission, plain TeX or LaTeX macros are available upon request. ------------------------------ From: Tina Flores Date: Thu, 12 Mar 92 09:52:09 EST Subject: Short Course on Numerical Optimization and Software SIAM WORKSHOP ON NUMERICAL OPTIMIZATION AND SOFTWARE Date: Sunday, May 10, 1992 Location: Hyatt Regency Hotel, Chicago, Illinois Lecturers and organizers: Jorge J. More' Stephen J. Wright Both lecturers are with the Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois The course will cover four main problem areas. These are nonlinear equations and nonlinear least squares, unconstrained optimization, constrained optimization, and global optimization. Registration Fees: SIAM Non- Member Member Student Advance $120 $135 $55 On-Site 135 155 75 Preprints, coffee and lunch are included in the registration fees. Attendees are advised to preregister for the short course. On-site registration cannot be guaranteed. Preprints of the lecture materials will be distributed upon check-in at the SIAM registration desk. The short course will precede the Fourth SIAM Conference on Optimization which will be held on Monday through Wednesday, May 11-13, 1992, Hyatt Regency Hotel, Chicago, Illinois. Deadline for Advance Registration: May 4, 1992 Register NOW! By phone: 215-382-9800. By FAX: 215-386-7999. by E-mail: meetings@siam.org ------------------------------ From: Joel Saltz Date: Wed, 11 Mar 92 17:16:50 -0500 Subject: Scalable High Performance Computing Conference SCALABLE HIGH PERFORMANCE COMPUTING CONFERENCE SHPCC '92 Sponsored by IEEE Computer Society April 27-29, 1992 Williamsburg Hilton and National Conference Center Williamsburg, Virginia ADVANCE PROGRAM SUNDAY, April 26, 1992 Tutorials Computational Fluid Dynamics on Parallel Machines - Algorithms and Applications, Ramesh Agarwal, McDonnell Douglas Research Laboratories Using Massively Parallel Supercomputers: An Applications Perspective Horst Simon, Computer Sciences Corporation, NASA Ames Research Center Compilers for Scalable Architectures, Ken Kennedy, Rice University and Joel Saltz, ICASE SUNDAY, 6:00-9:30, Registration and Reception MONDAY Scalability of Data Transport, Harry Jordan, Univ. of Colorado Parallel sessions on: Applications and Performance Parallel sessions on: Applications and Languages Interleaved Mass Storage: Parallel Processing in Secondary and Tertiary Memory, Randy Katz, UC-Berkely Parallel sessions on: Algorithms and Systems Support for Languages Parallel sessions on: Molecular Dynamics and Tools Evening: Technical Vendor Presentations TUESDAY Parallel Methods and Applications for Macromolecular Simulations, Bernard Brooks, National Institutes of Health Parallel sessions on: Molecular Dynamics and Support for Irregular Problems Parallel sessions on: Computational Fluid Dynamics and Systems Issues Computational Aerodynamics with Unstructured Meshes, Dimitri Mavriplis, ICASE Parallel sessions on: Communication and Tools Parallel sessions on: Computational Fluid Dynamics and Compilers Evening: Panel on Educational Issues in Parallel Computing WEDNESDAY Performance Animation, Dennis Gannon, Indiana Univ. Parallel sessions on: Applications and Languages Parallel sessions on: Applications and Performance For a complete elecronic or hard copy of the Advance Program including a hotel reservation card, contact emily@icase.edu. ------------------------------ From: Willard Miller Date: Fri, 13 Mar 92 11:11:14 CST Subject: IMA Workshop on Linear Algebra for Signal Processing IMA Workshop on LINEAR ALGEBRA FOR SIGNAL PROCESSING April 6 -- April 10, 1992 Organizers: A. Bojanczyk and G. Cybenko Signal processing is making increasingly sophisticated use of linear algebra on both theoretical and algorithmic fronts. The purpose of this workshop is to bring signal processing engineers, computer engineers, and applied linear algebraists together for an exchange of problems, theories and techniques. Particular emphasis will be given to exposing broader contexts of the signal processing problems so that the impact of algorithms and hardware will be better understood. The workshop will explore five areas by having a sequence of talks devoted to the underlying signal processing problem, the algorithmic and analytic techniques and, finally, implementation issues for each area. The five areas are: 1) updating SVD and eigendecompositions; 2) adaptive filtering; 3) structured matrix problems; 4) wavelets and multirate signal processing; 5) linear algebra architectures (parallel/vector and other high performance machines/designs). Most of the workshop talks will be held in Conference Hall 3-180 on the entry floor of the Electrical Engineering/Computer Science Building. This building is located on the corner of Washington Avenue and Union Street, a block from the IMA Main Office. The conference hall is on the Ethernet and has a projection system for display of computer output. TENTATIVE SCHEDULE Monday, April 6 Gene Golub, Stanford/IMA The canonical correlations of matrix pairs and their numerical computation Franklin T. Luk, Rensselaer Polytechnic University Adaptive parameter estimation in signal processing J. Cadzow, Vanderbilt University Marc Moonen, Katholieke U. Leuven Systolic algorithms for adaptive signal processing Wenyuan Xu, University of Minnesota New ideas in the design of signal-subspace detectors and estimators Robert J. Plemmons, Wake Forest University/IMA Preconditioned iterative least squares FIR system identification Tuesday, April 7 Gilbert Strang, MIT Wavelet transforms versus Fourier transforms A. H. Tewfik, University of Minnesota Wavelets in signal and image processing Martin Vetterli, Columbia University Wavelets, filter banks, and applications in compression Jo Ward, Murdoch University Stability of DARMA filters on spaces M. Stewart, University of Illinois A general linear algebraic framework for perfect reconstruction filters Lothar Reichel, Kent State University Wednesday, April 8 Simon Haykin, McMaster University Fast implementation of the RLS algorithm A. Steinhardt, Cornell University Adaptive detection using sensor arrays John Proakis, Northeastern University Blind equalization Thursday, April 9 Pierre Comon, Thomson Sintra, France Looking for fast algorithms solving structured linear systems Tom Kailath Stanford University Israel Koltracht, University of Connecticut Structured condition numbers Georg Heinig, Universitaet Leipzig/IMA Fast algorithms for generalized Cauchy matrices and rational interpolation Gregory Ammar, Northern Illinois University Updating and downdating Szego polynomials Friday, April 10 Robert Schreiber, NASA Ames Research Center/IMA Matrix computation on SIMD data-parallel architectures E. Deprettere INSTITUTE FOR MATHEMATICS AND ITS APPLICATIONS University of Minnesota 514 Vincent Hall 206 Church Street S.E. Minneapolis, Minnesota 55455 FAX (612) 626-7370 telephone (612) 624-6066 ------------------------------ From: Joseph Oliger Date: Fri, 13 Mar 92 14:34:51 PST Subject: Visiting Positions at RIACS RESEARCH INSTITUTE FOR ADVANCED COMPUTER SCIENCE NASA Ames Research Center Moffett Field, CA The Research Institute for Advanced Computer Science (RIACS) at the NASA Ames Research Center, located in the San Francisco Bay Area adjacent to Silicon Valley, is inviting applications for visiting research positions for graduate students for the summer of '92 and for post-doctoral appointments of up to two years begining in the Fall of '92. RIACS carries out a basic research program in the computational sciences to support the needs of NASA Ames scientific missions. Specific areas of interest are: algorithms and software for parallel scientific computation with applications to computational fluid dynamics, adaptive and composite mesh methods for solving partial differential equations, the design and implementation of compilers and tools for parallel computers, and the analysis of high performance networks. The computing environment at NASA Ames Research Center includes a Connection Machine (CM-2), an Intel iPSC/860, a Cray Y-MP and a Cray-2. High performance graphics workstations are also available. Visitors to RIACS are expected to collaborate with NASA Ames scientists. Additional opportunities for collaboration abound with the many local research universities and institutions. Applicants should send resumes and descriptions of research interests with references to: Joseph Oliger, Director RIACS NASA Ames Research Center Mail Stop T041-5 Moffett Field, CA 94035-1000 Applications and inquiries may also be made via e-mail to: oliger@riacs.edu RIACS is an Equal Opportunity Employer. (PLEASE POST) ------------------------------ From: Richard A. Brualdi Date: Tue, 10 Mar 92 16:37:35 CST Subject: Contents: Linear Algebra and its Applications Contents of LAA Volume 167, April 1, 1992 Preface 1 Daniel Hershkowitz (Haifa, Israel) The Height Characteristic of Block Triangular Matrices 3 Naomi Shaked-Monderer and Abraham Berman (Haifa, Israel) More on Extremal Positive Semidefinite Doubly Stochastic Matrices 17 Pal Rozsa (Budapest, Hungary) and Francesco Romani (Pisa, Italy) On Periodic Block-Tridiagonal Matrices 35 S. W. Hadley (Waterloo, Canada), F. Rendl (Graz, Austria), and H. Wolkowicz (Waterloo, Canada) Symmetrization of Nonsymmetric Quadratic Assignment Problems and the Hoffman-Wielandt Inequality 53 Bit-Shun Tam (Tamsui, Taiwan) On the Structure of the Cone of Positive Operators 65 Adi Ben-Israel (New Brunswick, New Jersey) A Volume Associated With mxn Matrices 87 Mark Krupnik (Haifa, Israel) Changing the Spectrum of an Operator by Perturbation 113 Michael Gorodetsky (Haifa, Israel) Inversion of Quasitriangular Block Toeplitz Matrices 119 J. C. Willems (Groningen, The Netherlands) and P. A. Fuhrmann (Beer Sheva, Israel) Stability Theory for High Order Equations 131 Moshe Roitman and Zalman Rubinstein (Haifa, Israel) On Linear Recursions With Nonnegative Coefficients 151 Yoav Yaacoby and Peter R. Cappello (Santa Barbara, California) Decoupling the Dimensions of a System of Affine Recurrence Equations 157 Avram Sidi (Haifa, Israel) Development of Iterative Techniques and Extrapolation Methods for Drazin Inverse Solution of Consistent or Inconsistent Singular Linear Systems 171 Abraham Berman, Moshe Goldberg, and Daniel Hershkowitz (Haifa, Israel) REPORT: Haifa 1990 Conference on Matrix Theory 205 Author Index 273 ------------------------------ End of NA Digest ************************** -------