Subject: NA Digest, V. 92, # 46 NA Digest Sunday, December 6, 1992 Volume 92 : Issue 46 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: A Proposal for a Fast QR Algorithm Medical Imaging Algorithms (Tomography) Workstations for a Blind Numerical Analyst Leslie Fox Prize Maple V Release 2 Postdocs at Cornell New Positions at University of South Florida Chaotic Numerics Conference Computational Techniques Conference Bristol-Bath Numerical Analysis Day IMACS Conference on Expert Systems for Numerical Computing Workshop on Network Optimization Numerical Analysis with Automatic Result Verification IMACS Annals of Computing and Applied Mathematics 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: Francois Robert Date: Mon, 30 Nov 1992 16:36:28 +0100 Subject: A Proposal for a Fast QR Algorithm My 92-93 students had a "brillant" idea for the QR algorithm for eigenvalues of a matrix A: Instead of iterating the standard (QR factorization, followed by a RQ computation) they suggest: * Square A p times: you get A to the power k= 2**p * Then, factorize into QR * then, compute A(k+1) = Qtransposed*A*Q This procedure saves much computational time. However there is a problem with the squaring. It is quite possible to normalize (just as for the power method) This normalization does not change Q Finally my students tested the following procedure: 1) Perform the process with p=4. You get A(16) 2) Iterate the whole process with A(16): Then you can follow the evolution. On examples with n = 10, they saved half the computational time or more. The shift process remains unchanged. Did you hear somewhere of this quite natural method? Thanks for your help, "THE CAL'MAT' (calcul matriciel) GROUP" (Lionel CHAILAN, Emmanuel FOLLET et al., driven by, Francois ROBERT robert@imag.imag.fr F. ROBERT frobert@alize.imag.fr ENSIMAG, BP 53X F-38041 Grenoble Cedex frobert@imag.imag.fr Tel. (33) 76 51 47 15 ------------------------------ From: Rosie Renaut Date: Mon, 30 Nov 1992 11:51:42 -0700 Subject: Medical Imaging Algorithms (Tomography) We are looking for recent algorithms for the solution of the following problem: Given two images f(x,y,z), g(x,y,z) of the same object it is known that one can be obtained from the other by rotation and translation. Suppose that there exist angles (ax,ay,az) and displacements (dx,dy,dz) and a scalar s such that f is obtained from g by the rotations, displacements and scalar multiplying factor. What is the most effective way to find these 7 parameters? Comments on parallel implementations for the solution of this problem also useful Thanks Replies to: qhe@enuxmp1.eas.asu.edu (Qing He) ------------------------------ From: Wojciech Owczarz Date: Thu, 3 Dec 92 11:37:45 CET Subject: Workstations for a Blind Numerical Analyst I am implementing the numerical analysis software. I am blind and work with several mainframe systems by using my PC with vista-card plus sound. I want to use a workstation, therefore I am looking for a contact with another blind numerical analyst who has experience with X-windows on a workstation, ideally working with the implemen- tation of packages for numerical computation. Wojciech Owczarz The Danish Computer Center for Research and Education (UNI-C) DTH, Bldg. 305 DK-2800 Lyngby, Denmark Email: wojciech.owczarz@uni-c.dk Tel: +45 42 88 39 99 + (after the tone) 2406 Fax: +45 45 93 02 20 ------------------------------ From: Nancy Nichols Date: 3rd December 1992 18:46:28 GMT Subject: Leslie Fox Prize LESLIE FOX PRIZE SIXTH PRIZE COMPETITION AND HONORARY SYMPOSIUM This year the Leslie Fox Prize Competition meeting is to be held in conjunction with a special symposium to honour the memory of Leslie Fox and to celebrate his many important contributions to numerical analysis and the numerical analysis community. The combined Leslie Fox Prize Meeting and Honorary Sympos- ium are to be held in Oxford on the 24th and 25th June, 1993. At this time, entires for the Fox Prize Competition are being invited. Further information concerning the full two-day meeting will be published at a later date. Entries for the Sixth Leslie Fox Prize Competition are now being accepted. Any person who is less that 31 years old on January 1, 1993, and has not already won a first prize is eligible. Each entry should consist of three copies of a paper, describing some of the candidate's research, that is suitable for a 40 minute lecture at a numerical analysis symposium. Whether or not the work has been published or accepted for publication is irrelevant, but no person may submit more that one paper. Unsuccessful candidates from previous competitions are encouraged to enter. The entries will be considered by an Adjudicating Committee. The Committee for the Sixth Prize Competition are: Dr Nancy Nichols (Reading, chairman) Professor Charles Elliott (Sussex) and Professor Christopher Baker (Manchester) Particular attention will be given to the originality and quality of each paper and to the suitability of the material for a 40 minute talk to a general audience of numerical analysts. Papers will be selected by the Committee for presentation at the Leslie Fox Prize meeting. Only the papers that are presented at the meeting will be eligible for awards, but, subject to this restriction the Adjudicating Committee may award any number of first and secondary prizes. Entries for the Competition should be received by the chairman by FEBRUARY 1, 1993. Please note that because of the change in dates of the meeting, the entry date has been extended by two months. Each candidate should include a statement of his/her date of birth and should indicate that he/she would be available to present his/her paper at the symposium. A joint paper may be submitted by an individual candidate if accompanied by a statement from the co-authors agreeing to the submission and detailing the candidate's contribution to the paper. Travel funds are not generally provided to assist candidates who attend the symposium. The prizes are derived from a capital fund to which DONATIONS would be gratefully received at any time. It is a registered non-profit fund, so that US citizens can claim tax exemption and UK contributors can covenant the money enabling reclaim of UK tax by the fund. Anyone wishing to contribute to the fund should contact Nancy Nichols at the address below. Alternatively, contributions can be sent to the Institute of Mathematics and its Applications, Southend-on-Sea, UK, which can provide covenant forms. In this year of Leslie's death we are making a special effort to put the Prize Fund on a sound financial footing, to ensure its continuation into the future. We are therefore asking Leslie's friends and colleagues to consider making a special contribution to the Fund in his honour. Leslie's wife Clemency is taking a special interest in the survival of the Prize Fund, and if anyone wishes to make a donation as a memorial, we shall be pleased to notify her that a gift has been made to the Fund. Nancy Nichols Tel. +44-734-318988 Department of Mathematics Fax. +44-734-313423 University of Reading email: n.nichols@reading.ac.uk Box 220 Reading Berks RG6 2AX UK ------------------------------ From: Michael Monagan Date: Mon, 30 Nov 92 12:14:08 +0100 Subject: Maple V Release 2 Announcement of Maple V Release 2 Maple V Release 2 is available for Sun 4/SPARC and DEC Unix systems. We expect to complete ports to other Unix platforms by year end, and availability on other platforms will follow in the new year. Release 2 incorporates a completely new user interface and many new graphical capabilities. The nicest feature of the new interface is the high quality output of formulae in true mathematical notation. The new graphical capabilities include contour plots, implicit plots (2D and 3D), vector plots (2D and 3D), animation (2D and 3D), and basic support for text, polygons, color, lighting, etc. Maple, Maple V Release 2 also includes many new and improved mathematical capabilities. A focus of this version has been given to fixing bugs, fixing design problems, and to improving the numerical capabilities, in particular, complex numeric arithmetic, numerical linear algebra, and numerical solutions to polynomials. A LaTeX document detailing the new facilities and improvements, with examples in Maple V Release 2, can be obtained from the Maple share library using anonymous ftp from neptune.inf.ethz.ch or daisy.uwaterloo.ca. Get the file summary.tex from the directory maple/5.0/tex and the style files. Inquiries about Release 2 should be addressed to Waterloo Maple Software, 160 Columbia Street West, Waterloo, Ontario, Canada, N2L 3L3 Phone: (519) 747-2373 FAX: (519) 747-5284 Email: info@maplesoft.on.ca ------------------------------ From: Tom Coleman Date: Tue, 1 Dec 92 11:26:56 -0500 Subject: Postdocs at Cornell CORNELL THEORY CENTER Postdoctoral Fellowships The Cornell Theory Center invites applications for postdoctoral fellowships in the computational sciences. Fellows will be expected to work with a faculty mentor and applications should designate a prospective mentor, if possible. The Cornell Theory Center contains one of four National Science Foundation Supercomputing facilities. The Center operates several high performance computers, including an IBM ES-9000, an IBM Power Visualization System, a cluster of IBM RS-6000 workstations, and a Kendall Square KSR-1 computer. An Intel iPSC/860 and Thinking Machines Connection Machine CM200 are operated by the Cornell Computer Science Department. The Theory Center is also the parent organization for the Advanced Computing Research Institute, a research group with an emphasis on parallel computation and with close ties to the Computer Science Department. We invite applicants interested in all aspects of computational science and engineering. Applications and supporting letters of reference should be sent to J. Addy, Personnel Manager, Cornell Theory Center, 529 Engineering & Theory Center Bldg., Cornell University, Ithaca, NY 14853-3801 Cornell University is an Equal Opportunity Educator and Employer ------------------------------ From: E. B. Saff Date: Wed, 2 Dec 92 14:40:18 EST Subject: New Positions at University of South Florida THE UNIVERSITY OF SOUTH FLORIDA We invite applications for two tenure-track positions at the Assistant Professor level effective August, 1993, contingent on availability of funds. Applicants must have or expect to have a PhD in mathematics upon assuming the position, and must show evidence of strong research potential. Candidates demonstrating research experience beyond the PhD are particularly encouraged to apply. The duties include research activity and both graduate and undergraduate teaching. We encourage applications from the following fields: Analysis, Discrete Mathematics/ Foundations of Computing, Numerical Analysis, Probability. Applicants must indicate in which of these four fields they wish to be considered, although outstanding candidates in other areas may apply. The University of South Florida is the second largest state university in the Southeast, with more than 34,000 students enrolled. The Mathematics Department offers BA, MA, and PhD degrees. To apply, send a letter of application and a curriculum vitae, and arrange to have at least three letters of recommendation sent to: Kenneth L. Pothoven, Chair, Department of Mathematics, University of South Florida, 4202 E. Fowler Ave., PHY 114, Tampa, FL 33620-5700 (e-mail: mathdept@math.usf.edu, fax: (813) 974-2700). Applications, which may be submitted by e-mail or fax, must be submitted by Feb. 1, 1993. U.S.F. is an Equal Opportunity/Affirmative Action Employer, and follows ADA guidelines. ------------------------------ From: Anthony D Klemm Date: Mon, 30 Nov 92 10:54:14 +1100 Subject: Chaotic Numerics Conference CHAOTIC NUMERICS An International Workshop on the Approximation and Computation of Complicated Dynamical Behaviour 12-16 JULY 1993 DEAKIN UNIVERSITY GEELONG AUSTRALIA Much of what we know about specific dynamical systems is obtained from numerical experiments. Not only can we visualise the dynamics, we can also evaluate key characteristics such as bifurcation parameters, Lyapunov exponents, Hausdorff dimension or entropy. The discretization procedure usually has no significant effect on the results for relatively simple, well-behaved dynamics. On the other hand, acute sensitivity to changes in initial conditions is a hallmark of chaotic behaviour, so how confident can we be that the numerical dynamics reflects that of the original system? Do we always obtain a nearby attractor, homoclinic orbit or inertial manifold? Do numerically calculated trajectories always shadow a true one? In brief, what role does numerical analysis have in the study of dynamical systems? Conversely, can recent advances in dynamical systems theory provide new insights into our understanding of numerical algorithms? The purpose of this workshop is to provide a forum for researchers and practitioners to discuss these fascinating issues at the interface of numerical analysis and dynamical systems theory, and their implications in science and engineering. KEYNOTE SPEAKERS W.J. Beyn University of Bielefeld S.N. Chow Georgia Institute of Technology J. Hale Georgia Institute of Technology J. Lorenz University of New Mexico Each keynote speaker and other invited speakers will present survey and research lectures. Short talks or computing demonstrations from conference participants are invited. A proceedings of selected papers will be published by an international publisher and sent to participants after the workshop, the cost being included in the registration fee. PROGRAM COMMITTEE P.Kloeden (Geelong) K. Palmer (Miami) K. Burrage (Brisbane) A. Pokrovskii (Moscow) For additional registration forms and information please contact one of the organisers: Prof. P.E. Kloeden School of Computing and Mathematics Deakin University Geelong Victoria 3217 Australia Email: kloeden@cm.deakin .edu.au Prof. K.J. Palmer Dept. of Mathematics and Computer Science University of Miami Coral Gables Florida 33124 USA Email kjp@paris.cs.miami.edu Chaotic Numerics is sponsored by the Australian Mathematical Society and Deakin University ------------------------------ From: Anthony D Klemm Date: Mon, 30 Nov 92 10:59:14 +1100 Subject: Computational Techniques Conference THE 6TH BIENNIAL COMPUTATIONAL TECHNIQUES AND APPLICATIONS CONFERENCE AUSTRALIAN NATIONAL UNIVERSITY JULY 5th-9th, 1993 About the Conference CTAC93 is the sixth biennial conference on computational techniques and applications organised by the Computational Mathematics special interest group of the Applied Mathematics Division of the Australian Mathematical Society. The conference, to be held on July 5, 6 and 7, provides an opportunity for the developers and implementors of computational methods to interact with those applying the technology to problems in engineering and science, in particular. The workshops, to be held on July 8 and 9, provide in-depth treatment of important recent developments in particular areas of computational mathematics and computing technology. Venue The conference and workshops will be held in the Faculties area of the Australian National University adjacent to the School of Mathematical Sciences. Close by are the Student Union and the concessions area which provide a range of commercial, eating, entertainment and sporting facilities. The venue is only a few minutes walk from the city centre. Invited Speakers Anthony Cooper (Lausanne): Stability calculations in MHD and Plasmas. Charles Elliott (Sussex): Numerical Analysis of the Phase Field Equations and Phase Boundary Motion. David Green (ANU): Numbers versus rules? Alternative paradigms in biocomputing. Andreas Griewank (Argonne): Challenges in computational differentiation. Steve McCormick (U.C. Denver): Multilevel projection methods. Joe Monaghan (Monash): Particle methods. Workshops The final two days of CTAC93 will be devoted to workshops consisting of groups of related presentations in areas of specific interest. The basic format for each presentation will consist of two lectures. The first will have the character of an area survey and will be followed by a second which will treat some aspect in greater depth. The workshops that have been organised are: `Computational problems in fluids, MHD, and plasmas.' Organiser: Henry Gardner, Theoretical Physics, ANU. `Optimization, complementarity problems, and variational inequalities.' Organisers: David Stewart, School of Mathematical Sciences, ANU, and Robert Womersley, School of Mathematics, UNSW. `Programming distributed memory multiprocessors.' Organisers: David Singleton, Supercomputer Facility, ANU, and Lindsay Hood, TMC. CTAC Lecture Mr. Trevor Robinson, adviser to the Minister for Industry, Technology and Commerce will give an individual view of supercomputer developments and related policy and application questions in science and industry. This keynote address will be held in Bruce Hall on Tuesday evening, July 6, and will include dinner. Guests of participants are welcome to attend, at a cost of $40.00 per guest. This fee for guests should be paid with the registration fee. Conference Information An information file on the Conference, `ctac93.info', is held in the ftp directory pub/CTAC93 on thrain.anu.edu.au and is available for access by anonymous ftp (log in as anonymous and use your email address as password). This is a directory to files containing preliminary information on the programs for the conference and workshops, general information about the conference venue, instructions for preparing abstracts and papers etc. General inquiries may be directed to ctac-reg@thrain.anu.edu.au ------------------------------ From: Andy Wathen Date: Wed, 2 Dec 92 16:31:22 GMT Subject: Bristol-Bath Numerical Analysis Day The next BRISTOL-BATH NUMERICAL ANALYSIS DAY will be held in Lecture Theatre SM2, School of Mathematics, University Walk, Bristol, UK on Wednesday 6th January 1993. All are invited to attend this informal (and free!) set of talks on current research to be given by local speakers: Yves Tourigny, Ivan Graham, Alan Champneys, Alison Ramage, Adrian Hill, Chris Budd and our `guest' speaker, Dr Nick Higham of Manchester University. The talks will start at 10:45 preceded by coffee (from 10:15), and will end at 16:05. For full programme contact: Andy Wathen (+44 0272 303313) (andy.wathen@bristol.ac.uk) ------------------------------ From: Karen Hahn Date: Wed, 2 Dec 92 15:12:49 EST Subject: IMACS Conference on Expert Systems for Numerical Computing 3rd. IMACS INTERNATIONAL CONFERENCE ON EXPERT SYSTEMS FOR NUMERICAL COMPUTING May 17-19, 1993 Purdue University West Lafayette, Indiana, USA Conference Rationale: Many diverse groups have started work on projects to aid in the use of complex software systems, and to guide nonspecialists in the many choices that have to be made when they want to use computers for scientific applications. This international conference will bring together active researchers to exchange ides, viewpoints, and techniques. Topics of Interest (include, but are not limited to): * Artificial intelligence and expert systems for numerical computing (e.g. for numerical solution of ordinary or Partial differential equations, integral equations, linear systems...) * Knowledge-based systems for scientific application * Expert systems for mapping applications to parallel architectures and to support parallel processing * Advisory expert systems for general-purpose scientific software libraries * Tools and methods for knowledge acquisition about numerical computing * Problem solving environments for scientific/engineering applications * Natural language for scientific interfaces Submission of Papers: The conference will include invited and contributed papers. Authors should submit three copies of an extended abstract (two or three typewritten pages) by January 15, 1993. Contributors will be notified regarding acceptance by February 28, 1993. Deadline for final manuscripts is June 1, 1993. Abstracts and inquiries should be sent to the conference coordinator: Dr. Elias Houstis Purdue University 1398 Computer Science Building West lafayette, IN 47907, USA Tel: 317-494-6181 Fax: 317-494-0739 e-mail: enh@cs.purdue.edu Organizing Committee: E. Houstis (Purdue); J. R. Rice (Purdue); R. Vichnevetsky (Rutgers) Program Committee: W. Enright (U. of Toronto); E. Gallopoulos (U. of Illinois) I. Gladwell (Southern Methodist U.); E. Kant (Schlumberger Lab); T.S. Papatheodorou (U. of Patras, Greece); R. L. Peskin (Rutgers U.) F. Rechenmann (INRIA, France); S. Steinberg (U. of New Mexico); Y. Umetani (Hitachi Ltd., Japan) ------------------------------ From: Federico Malucelli Date: Fri, 4 Dec 92 18:47:33 MET Subject: Workshop on Network Optimization ANNOUNCEMENT AND CALL FOR PAPERS NETFLOW93 AN INTERNATIONAL WORKSHOP ON NETWORK OPTIMIZATION: THEORY AND PRACTICE October 3-7, 1993 Centro Studi "Cappuccini", Cassa di Risparmio di S. Miniato, San Miniato (PI) Italy. Sponsored by: Mathematical Programming Society Hewlett-Packard Italy Ltd. IBM Italy Ltd. Italian Operations Research Society CNR - Progetto Finalizzato Trasporti Universita' di Pisa This workshop will emphasize recent theoretical and computational advances in the field of network optimization, related continuous and combinatorial optimization problems, implementations and applications. Netflow93 will be organized in sequential sessions of invited and contributed papers with sufficient time for individual discussions among participants. TOPICS: A variety of topics will be accommodated, such as single and multicommodity network flows, matching, network design, scheduling theory and algorithms, computational complexity, graph partitioning algorithms, nonlinear network optimization, combinatorial optimization, large-scale network optimization, fast approximation algorithms, implementations and computational experimentation, as well as significant applications. EXTENDED ABSTRACTS and FULL PAPERS: Contributed papers will be selected by the Program Committee on the basis of Extended Abstracts. Extended abstracts for all talks will be made available to participants during the Workshop. The Netflow93 Proceedings, planned for 1994 as a Mathematical Programming-B journal volume, will contain full papers which will be refereed according to the established policies of the journal. INTERNATIONAL PROGRAM COMMITTEE: G. Gallo, D. Goldfarb, M.D. Grigoriadis, M. Grotschel, L.G. Khachiyan, F.T. Leighton, J.K. Lenstra, T.L. Magnanti, J.B. Orlin, W.R. Pulleyblank, B. Simeone, E. Tardos, R.E. Tarjan, P. Toint. Netflow93 CO-CHAIRMEN: Giorgio Gallo and Mike Grigoriadis. LOCATION: The workshop will be held in the Centro Studi "Cappuccini", a recently restored medieval monastery on the hills of the historic town of San Miniato, located midway between Pisa and Florence, an area rich in cultural sites. DATES: April 15, 1993: All Extended Abstracts received in Italy. May 15, 1993: Notification to authors. August 31, 1993: Revised Extended Abstracts received in Italy. October 3, 1993: Arrival at San Miniato. October 4-6, 1993: Netflow93 Workshop. October 7, 1993: Departure. December 31, 1993: Full papers received by either Co-Chairman of Netflow93 for refereeing and possible publication in Mathematical Programming-B. INFORMATION and CORRESPONDENCE: Please send all inquiries, applications for registration and Extended Abstracts to: Federico Malucelli, Chairman Local Organizing Committee - Netflow93 Dipartimento di Informatica Universita di Pisa Corso Italia 40, 56125 Pisa, Italy. e-mail: maluc@di.unipi.it Phone: +39 -50 510216 Fax: +39 -50 510226 ------------------------------ From: Ralph B Kearfott