From nacomb@surfer.EPM.ORNL.GOV Sun Feb 9 19:25:35 1992 Return-Path: Received: from surfer.EPM.ORNL.GOV by CS.UTK.EDU with SMTP (5.61++/2.7s-UTK) id AA22407; Sun, 9 Feb 92 19:25:28 -0500 Received: by surfer.EPM.ORNL.GOV (5.61/1.34) id AA07943; Sun, 9 Feb 92 19:25:12 -0500 Date: Sun, 9 Feb 92 19:25:12 -0500 From: nacomb@surfer.EPM.ORNL.GOV (NA-NET) Message-Id: <9202100025.AA07943@surfer.EPM.ORNL.GOV> Subject: NA Digest, V. 92, # 6 Apparently-To: dongarra@cs.utk.edu Status: R NA Digest Sunday, February 9, 1992 Volume 92 : Issue 6 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: Happy New Year Past Issues of the NA-Net Digest. Is the CPC Program Library Online? Don't Supresss the Wiggles SIAM Conference on Control and Its Applications Refereeing NSF Grand Challenge Application Groups IFIP WG2.5 Position Paper on LCAS Permian Basin Supercomputing Conference 1992 IMA Workshop on Linear Algebra for Control Theory Scientific Computing Workshop for Faculty Scientific Computing Workshop for Students Announcement for SIAM Texas--Oklahoma Meeting Team Leader position at CERFACS Position at University of Dortmund Position at National Central University of Taiwan Report on Extrapolation and Rational Approximation meeting 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: Gene Golub Date: Tue, 4 Feb 92 22:42:29 CST Subject: Happy New Year We wish all our Chinese and Asian coleagues a very happy and healthy Year of the Monkey. Jack, Gene, Cleve and Bill -- the NA-net Gang of Four ------------------------------ From: Bill Rosener Date: Mon, 3 Feb 92 13:37:44 -0500 Subject: Past Issues of the NA-Net Digest. Past issues of the NA-NET Digest can be obtained through netlib. For help on using netlib, send mail to: netlib@ornl.gov Have the first line of your mail message be "send index" To obtain the NA-NET Digest index send the following message mail netlib@ornl.gov Subject: send index from na-digest If you know the year and issue you are looking for, then send a message similar to the one below. The following message would return issue number 4 from the year 1992. mail netlib@ornl.gov Subject: send v92n04 from na-digest -- Bill Rosener ------------------------------ From: Jim Kirkpatrick Date: Mon, 3 Feb 1992 14:18 MST Subject: Is the CPC Program Library Online? I recently obtained copies of some articles on random number generators, published in Computer Physics Communications. Apparently, source code for examples are available from the "CPC Program Library," Queen's University in Belfast. Does anybody know if this library can be accessed via FTP or some other form of on-line service? In a few cases, the examples were not published in the article, so I can't even type them in! Sounds like a worthy adjunct to Netlib. Jim Kirkpatrick jimkirk@corral.uwyo.edu ------------------------------ From: Zahari Zlatev Date: Mon, 3 Feb 92 13:12:46 EST Subject: Don't Supresss the Wiggles Two weeks ago I sent a message to NA.DIGEST in which I asked a question about an old paper. I got more than 75 answers. I should like to thank everybody who answered or tried to answer my question. Quite a few people wanted to know more about the paper. There are two papers: one in proceedings and the other in Computers and Fluids. The full reference to the journal paper is: P. M. Gresho and R. L. Lee, "Don't surpress the wiggles -- they're telling you something", Computers and Fluids 9(1981), 223-253. Many people think it is worthwhile (re)reading this paper. I should add here that I do not know the authors and have not been asked to advertize for the paper. Best regards, Zahari Zlatev ------------------------------ From: Tina Flores Date: Fri, 07 Feb 92 15:47:15 EST Subject: SIAM Conference on Control and Its Applications SIAM Conference on Control and Its Applications September 17-19, 1992, Minneapolis, Minnesota The deadline to submit contributed abstracts has been extended to FEBRUARY 21, 1992. Submit now your 100-word abstract and title either by FAX to 215-386-7999, or by E-mail to meetings@siam.org To help in formatting your submission by electronic mail, plain TeX or LaTeX macros are available upon request. Call 215-382-9800 or send your request by e-mail to meetings@siam.org We look forward to your participation. The Conference Organizing Committee ------------------------------ From: Alan Karp Date: Mon, 3 Feb 92 10:17:57 PST Subject: Refereeing I have been following the discussion about refereeing in the NA digest with some interest. Like most of us, I write only fair, perfectly correct referee reports and receive biased, error plagued reviews of my work. I have no solution for the problem of people who refuse to referee papers or are always late with their reviews. However, I believe there is something we can do about poor reviews. Poor reviews fall into two categories, those that are cursory and those that are erroneous. The latter category includes both those that miss the point of the paper or some key point in it and those that are used as a forum for the reviewer to insult the authors. Cursory reviews are a problem because they let poor papers get published. The more poor papers that appear in the journals, the more readers rely on the reputation of the authors to decide what to read. This problem makes it hard for people not in the "club" to get their work read. Erroneous reviews of both kinds are a problem because they make it hard for good work to get published and clog the system with resubmissions, secondary reviews, and acrimonious correspondence. I believe that both sets of problems are caused by anonymous refereeing. (I have read all the letters touting the advantages of anonymity in Physics Today and disagree with them.) For the past 10 years I have been signing all my reviews. Revealing my identity to the authors has had two effects. I am very careful about making negative comments and pointing out errors, and I no longer find myself making off-hand remarks that might be taken as insulting. (I discovered this fact when rereading some anonymous reviews I had done years ago.) Does signing my name inhibit me? You bet it does. If I am not sure something is wrong, I either check carefully or ask a carefully worded question. I probably give more attention to criticisms in reviews than I do to the facts in my own work. (Someone will referee my papers and check them for me.) What about a graduate student or assistant professor reviewing the work of a famous person? Can we expect errors to be pointed out? Of course we can if the errors are obvious. If there is only a difference of opinion, the senior person's view will carry more weight, as it would in any forum. What about reprisals? I reject your paper so you refuse to talk to me and instruct all your staff to reject my papers. First of all, if reviews are signed, you are less likely to review my work unfairly. Secondly, if I sign my name to a negative review, I am sure to have my facts straight even if we disagree about them. With our current system, I have heard of reprisals against innocent parties. ("It must have been Dokes who reviewed this paper. I'll get even with him some day.") Signing my name also gives me the luxury of contacting the authors directly if I have a question. Often, misunderstandings can be resolved in a few minutes instead of months of letter writing through an intermediary. Will doing away with anonymous reviewing lead to overly kind reviews? It may, but I have a solution to that problem and that of cursory reviews; attach the reviewers name to the paper! The reviewer will be forced to share the embarassment if any obvious errors appear in print. On the plus side, the reviewer will be given credit in print for the work done. (A list of referees for the year doesn't do it.) Often, there are honest differences of opinion. I have seen publications that follow a controversial paper with a statement from the referee and a rebuttal by the author. This discussion is the most enlightening part of these papers. I heartily recommend that all journals adopt this practice. By the way, I have only had two papers rejected for publication out of some 40 or so submitted. One was fully justified (I had made a critical error); the other was not (I will submit the paper elsewhere). ------------------------------ From: Mel Ciment Date: Mon, 3 Feb 1992 17:29:18 -0500 Subject: NSF Grand Challenge Application Groups ******** ABSTRACT OF ANNOUNCEMENT NSF 92-7 ****************** NATIONAL SCIENCE FOUNDATION OPPORTUNITIES IN HIGH PERFORMANCE COMPUTING AND COMMUNICATIONS a component of the U.S. High Performance Computing and Communications Program Fiscal Year 1992 Grand Challenge Applications Groups The National Science Foundation (NSF) announces opportunities for group oriented research for Fiscal Year 1992 in connection with the U.S. High Performance Computing and Communications (HPCC) Program. Six to eight proposals are expected to receive funding as Grand Challenge Application Groups as a result of the opportunities described in this initial announcement. Activities supported under this announcement are expected to achieve significant progress on Grand Challenge Applications - fundamental problems in science and engineering, with broad economic and scientific impact, whose solution could be advanced by applying high performance computing techniques and resources. This HPCC activity will provide funding for multidisciplinary groups of scientists, engineers, and mathematicians to apply emerging high performance computing and communications systems to advance the solution of diverse science and engineering problems. The emphasis will be on support for groups requiring HPCC capabilities, where such focused, cross disciplinary support is generally unavailable or difficult to obtain. Any area of science and engineering supported by NSF is eligible for funding under this solicitation. Grand Challenge Applications Groups are expected to employ testbed systems exploiting new and emerging computer and communications architectures, to prepare the groundwork for the HPCC goal of sustained teraflop computing on important application problems by the mid 1990's. Projects funded through this effort will focus on the fusion of disciplinary research with emerging high performance computing environments and architectures, within the framework of the HPCC program goals. It is anticipated that projects will include aspects of design of models, algorithms and software to fully realize the potential of parallel, distributed and heterogeneous computing systems on Grand Challenge Application problems. Awards are planned to be in the range of $300,000 to $800,000 per year for a period of three to five years, but there are no firm restrictions on size or duration. The number and size of awards will be based on the quality and potential impact of the proposals reviewed, and the availability of funds. Proposers interested in submitting a proposal must submit a letter of intent to NSF by March 9, 1992. The dealine for submission of proposals is April 30, 1992. To receive the full announcement, NSF 92-7, address requests to hpccgrps@nsf.gov, or utilize the NSF electronic dissemination Science and Technology Information System, STIS. ------------------------------ From: Lloyd Fosdick Date: Tue, 4 Feb 1992 21:53:03 -0700 Subject: IFIP WG2.5 Position Paper on LCAS The following position paper has been sent to the X3 Secretariat of the International Standards Organization (ISO) by Working Group 2.5 of the International Federation of Information Processing Societies (IFIP). John Reid is the principal author. Comments on Version 3.1 of Draft ISO/IEC 10967:1991 Language Compatible Arithmetic by Members of IFIP Working Group 2.5 (Numerical Software) 31 Jan 1992 An extremely encouraging development of the past several years for those concerned with constructing portable numerical software has been the increasingly widespread use of hardware that conforms to the IEEE standard for binary floating-point arithmetic (ISO/IEC 559:1989 and ANSI/IEEE 754-1985). This was designed with great care and has many features that assist the construction of software that is robust and executes rapidly. The proposed new standard specifies many desirable features for a floating-point type in a loose enough manner to encompass most of today's important hardware, though not Cray computers. Thus its adoption would put some pressure upon Cray Research to offer an alternative, but the pressure is there anyway since the workstation is becoming more and more the preferred mode of access and it is clearly desirable to be able to run small test cases on the workstation and see the same results for these cases on the supercomputer. The authors clearly have a problem in deciding how loose the requirements should be, but it is really very hard to understand why they regard as acceptable the VAX D-format with its very restricted range (about 10^(-38) to 10^(+38)) for its precision (about 17 decimals) and the IBM double precision format whose range (about 10^(-76) to 10^(+76)) is little better. The case that we wish to make is that the requirements should be very tight. The effect of a loose requirement is that software written to be robust in execution on all present and future machines that conform to a loose standard will be very verbose and probably slow in execution. An example is provided by Kahan (1991, Fig. 3). More likely is that programmers will not bother to add all these extra tests and the code will fail unexpectedly when moved to different hardware. An example of this is provided by Tydeman (1991), who considers the computation x / sqrt(x^2 + y^2) which might reasonably be expected never to yield a value greater than one. Such a tight specification is already provided by the IEEE standard for binary floating-point arithmetic, or the IEEE radix-independent standard for floating-point arithmetic (IEEE 854-1987), which has the great merit of permitting radix 10. Our suggestion is that any new standard be firmly rooted on these standards. A further very serious defect of the proposed new standard lies in its treatment of exceptions, for which 'notification' is required. Notification may consist either of alteration of the control flow of the program (the authors say this is their preferred choice) or the output of a message in a 'hard-to-ignore' manner. Alteration of the control flow is becoming an increasingly unrealistic choice on today's hardware - the run-time penalty on vector or parallel hardware may be prohibitive. The alternative of millions of lines of output messages is even more unacceptable. What is needed is a mechanism that records the event without interupting the execution flow. Corrective action can then be taken when it is needed, perhaps by repeating the calculation with a different algorithm or in a higher precision, without penalizing the normal case. An excellent foundation has been provided for such an approach in the IEEE standards, which reinforces the value of basing any new standard on these standards. Overall, one has the feeling that the proposed standard seeks to make the best of a bad situation (except that Cray arithmentic is regarded as beyond the pale). In fact, the situation has been improving steadily over the last few years as more and more computers with IEEE arithmetic come into use. The IEEE standard simplifies the problem of comparing and analyzing the results of computations. Computations performed on different machines can be compared and interpreted more easily, numerical software can be expected to produce consistent results on different systems, and so forth. The proposed new standard represents a turn away from a strict arithmetic standard, making such comparisons and interpretations far more difficult, and is thus detrimental to progress in scientific computation. References: Kahan, W. [1991]. Analysis and refutation of the LCAS. ACM SIGNUM Newsletter, 26, 2-15. Tydeman, F. [1991]. Comments on LCAS draft 3.1. Presented to X3T2 in July 1991. ------------------------------ From: Marcin Paprzycki Date: Tue, 4 Feb 1992 9:12:54 GMT-0600 Subject: Permian Basin Supercomputing Conference 1992 PERMIAN BASIN SUPERCOMPUTING CONFERENCE 1992 March 13-15 The University of Texas of the Permian Basin Odessa, Texas Invited Speakers Friday, March 13 I. Gladwell, Comparing Direct and Iterative Methods for Boundary Problems C. Bischof, LAPACK: Portable Linear Algebra Software Saturday, March 14 D.R. Kincaid, The ITPACK and NSPCG Software Packages R. Plemmons, Large-Scale Bock Toeplitz Least Squares Computations B.N. Datta, Large-Scale And Parallel Matrix Computations In Linear Control Sunday, March 15 Robert A. van de Geijn, Scalable Dense Linear Algebra Libraries D.C. Sorensen, An Implicitly Restarted Arnoldi Method Marcin Paprzycki, Conference Chairman Department of Mathematics and Computer Science University of Texas of the Permian Basin Odessa, TX 79762 Phone: (915) 367-2244 ------------------------------ From: Paul Van Dooren Date: Wed, 5 Feb 92 08:53:26 CST Subject: IMA Workshop on Linear Algebra for Control Theory IMA WORKSHOP on LINEAR ALGEBRA FOR CONTROL THEORY June 1--5 Minneapolis, Minnesota The Institute for Mathematics and its Applications will sponsor a workshop on linear algebra for control theory. This workshop is being held in the context of the Applied Linear Algebra Year. The number of talks has been limited in order to leave plenty of free time for informal discussions. In addition facilities will be made available for informal sessions in the late afternoons or evenings. Talks are grouped according to the following themes, with 4 or 5 speakers officially scheduled per theme : NUMERICAL LINEAR ALGEBRA FOR CONTROL (organized by A. Bunse-Gerstner and V. Mehrmann) A. Bunse-Gerstner, R. Byers, A. Laub, P. Van Dooren H-INFINITY CONTROL (organized by A. Ran) J. Ball, E. Jonckheere, D. Limebeer, H. Trentelman, M. Verma CANONICAL FORMS AND INVARIANTS (organized by D. Hinrichsen) T. Antoulas, P. Fuhrmann, U. Helmke, R. Ober, Praetzel-Wolters RING-THEORETIC METHODS IN LINEAR CONTROL (organized by E. Sontag and B. Wyman) J. Brewer, D. Cobb, G. Conte, E. Kamen MATRIX THEORY IN CONTROL (organized by L. Rodman) I. Gohberg, L. Lerer, V. Mehrmann, I. Zaballa Questions about the workshop can be directed to Paul Van Dooren, University of Illinois, Urbana, IL 61801 (vdooren@uicsl.csl.uiuc.edu). For details about local arrangements, please contact Willard Miller, IMA, University of Minnesota, Minneapolis, MN 55455 (miller@ima.umn.edu). ------------------------------ From: Lloyd Fosdick Date: Thu, 6 Feb 1992 09:55:07 -0700 Subject: Scientific Computing Workshop for Faculty Summer Workshop for Faculty High-Performance Scientific Computing University of Colorado, June 8 - 19, 1992 This residential workshop is designed for college faculty members interested in teaching scientific computing to undergraduate students. Its objectives are to present an early draft of course material we have developed to potential instructors, to critique it, and to discuss ways of incorporating it into a college curriculum. This material was developed for an undergraduate course in "High-Performance Scientific Computing" under a grant from the National Science Foundation. Students in our course learn to use high-performance workstations and supercomputers through laboratory exercises representative of scientific applications. The exercises include numerical computation, scientific visualization, and performance measurement. Our laboratory is equipped with DEC 5000 and SGI Indigo workstations, and Xterminals; supercomputers are accessed over a network. Approximately 60% of the workshop time will be devoted to laboratory sessions. The remainder will be devoted to tutorials on the course material and to discussions of how to teach this subject to undergraduates, including practical matters of hardware and software requirements, teaching methodology, and breadth and depth of the subject matter. Participants will reside in Kittredge Residence Halls on the campus. Classes and laboratory sessions will be held in the Engineering Center located nearby. Residence expenses (room and board) will be paid by a grant from the National Science Foundation. Transportation expenses will not be covered. Attendance will be limited to sixteen participants, selected according to these criteria: Statement of interest. This statement describes the applicant's interest in participating in this workshop and relevant academic experience. Satisfaction of prerequisites. The prerequisites are experience with the Unix operating system and C or Fortran, knowledge of undergraduate numerical analysis. Faculty members from four-year colleges are especially encouraged to apply. Inquiries and applications should be sent to: Professor Lloyd Fosdick, Dept. of Computer Science, University of Colorado, Boulder, CO 80309-0430; tel. (303) 492-7507; e-mail lloyd@cs.colorado.edu. APPLICATION DEADLINE MARCH 30 ------------------------------ From: Lloyd Fosdick Date: Thu, 6 Feb 1992 10:01:50 -0700 Subject: Scientific Computing Workshop for Students I would appreciate it if those of you who are in contact with undergraduate students would bring the following announcement to their attention: Summer Workshop for Undergraduates High-Performance Scientific Computing University of Colorado, May 25 - June 5, 1992 This residential workshop is designed for upper division undergraduate students who are interested in learning about the use of supercomputers, high-performance workstations, and visualization in scientific computing. Workshop participants will use a Connection Machine (CM 2), a Cray Y-MP, DEC 5000 and SGI Indigo workstations, AVS and IDL (scientific visualization tools) for solving problems in molecular dynamics, wave motion, and visualization of data. Participants will reside in Kittredge Residence Halls on the University campus. Classes and laboratory sessions will be held in the Engineering Center located nearby. Residence expenses (room and board) will be paid by a grant from the National Science Foundation. Transportation expenses will not be covered. Attendance at the workshop will be limited to sixteen students. Selection of participants will be based on the following criteria: Statement of interest. This statement describes why the applicant is interested in participating in the workshop, relevant academic experience and interests, and long-range goals. Letter of recommendation by faculty member. This letter should be written by a faculty member who has served as the student's academic advisor or teacher. It should describe the student's strengths, academic performance, and potential for achievement. Satisfaction of prerequisites. The prerequisites are: experience with the Unix operating system, two semesters of calculus, one semester of numerical analysis, two semesters of courses in physical or biological science. Inquiries and applications should be sent to: Professor Lloyd Fosdick, Dept. of Computer Science, University of Colorado, Boulder, CO 80309-0430; tel. (303) 492-7507; e-mail lloyd@cs.colorado.edu. APPLICATION DEADLINE MARCH 30 ------------------------------ From: J. C. Diaz Date: Sat, 8 Feb 1992 20:08:15 -0600 Subject: Announcement for SIAM Texas--Oklahoma Meeting SIAM Texas--Oklahoma Meeting April 3 to 4, 1992 Tulsa, Oklahoma Invited Speakers Dr. A. Yeremin Department of Numerical Mathematics Moscow, Russian Academy of Sciences Dr. L. Kolotilina St. Petersburg Branch of the V.A. Steklov Mathematical Institute Russian Academy of Sciences Dr. M. Minkoff Argonne National Laboratory The SIAM Texas--Oklahoma Section Meeting is to be held in Tulsa, Oklahoma, April 3 and 4, 1992. All talks will be in room M1 of the Keplinger Hall on the campus of the University of Tulsa, (E 5th Str. and S. Harvard Ave). The conference will run from 2:00 PM to 6:00 PM on April 3, and from 8:30 AM to 11:30AM and 1:00PM to 4:00 PM on April 4, 1992. The main theme of the conference will be Scientific Computing but contributed papers in all of areas of mathematical sciences are invited. If you would like to present a talk at the meeting send an abstract by March 15 to the organizers: J.C. Diaz, (diaz@babieco.mcs.utulsa.edu), R. Redner, (redner@tusun2.mcs.utulsa.edu), Department of Mathematical and Computer Sciences, The University of Tulsa, Tulsa, OK 74104-3189. Registration fee is $10 ($5 for students). Advanced registration will continue until March 23, 1992. For more information on travel, accommodations, etc., send e-mail to the same address. Lodging: A block of rooms have been reserved in the Westin Hotel, (3rd Str. and S. Main Ave.). Rates are $59 per night for double occupancy, or single occupancy. To obtain these rates you must make reservations before March 19 by telephoning 1-800-228-3000, and refer to SIAM. ------------------------------ From: Iain Duff Date: Wed, 05 Feb 92 16:30:20 GMT Subject: Team Leader position at CERFACS CALL FOR APPLICATION Position: Team leader of the Post-Processing and Visualisation Team at CERFACS. CERFACS ( Centre Europeen de Recherche et de Formation Avancee en Calcul Scientifique ) is a "Groupement d'Interet Public" which members are: Matra Marconi Space, Aerospatiale, CNRS, INRIA, ONERA, GIE informatique CEA, Meteo France, Institut national polytechnique de Toulouse, Universite Paul Sabatier, Region Midi-Pyrenees, Technopolis-Csata, Centre Commun de Recherche des Communautes Europeennes. CERFACS is located in Toulouse (South of France). CERFACS is a center of excellence whose expertise is the use of high performance computers to solve problems in applied science and in engineering and a focal point in Europe for reasearch and training in these areas. CERFACS is offering expertise in: - Parallel Algorithms - Computational Aerodynamics - Instabilities and Turbulence - Climate Modelling and Global Change Candidates should submit: 1- a detailed C.V. 2- a proposal of scientific program for the Visualization and Post-Processing Team Final application must be received before February, 29th, 1992 at: CERFACS Selection Commitee 42 Avenue Gustave Coriolis 31057 Toulouse Cedex FRANCE e-mail: adm@cerfacs.fr ------------------------------ From: University of Dortmund Date: Thu, 06 Feb 92 15:05:43 SET Subject: Position at University of Dortmund Am Fachbereich Mathematik der Universitaet Dortmund ist voraussichtlich eine UNIVERSITAETSPROFESSUR (C4) fuer GEOMETRIE zum 1. Maerz 1993 wiederzubesetzen. Vorzugsweise ist an einen(e) Vertreter(in) gedacht, der(die) sich in der Forschungsrichtung Diskrete Geometrie oder Computer - Orientierte Geometrie wissenschaftlich besonders ausgewiesen hat. Habilitation fuer das Fach Mathematik oder habilitationsadaequate Leistungen werden vorausgesetzt. Es wird die Beteiligung an der Ausbildung der Studenten der Mathematik und anderer Fachrichtungen erwartet. Im uebrigen richten sich die Einstellungsvoraussetzungen nach Paragraph 49 WissHG des Landes NRW. Schwerbehinderte Bewerber(innen) mit gleicher Eignung werden bevorzugt behandelt. Die Universitaet strebt eine Erhoehung des Anteils von Frauen in Forschung und Lehre an und bittet deshalb Wissenschaftlerinnen nachdruecklich um ihre Bewerbung. Bewerbungen werden mit den ueblichen Unterlagen erbeten bis zum 1. Maerz 1992 an den Dekan des Fachbereichs Mathematik, Universitaet Dortmund, Postfach 50 05 00, 4600 Dortmund 50, Tel. (0231) 755(1)-3050. Bitte benutzen Sie nur den brieflichen Weg fuer Ihre Bewerbung, der Dekan. ------------------------------ From: Wei-Chang Shann Date: Sat, 8 Feb 92 23:18:25 -0500 Subject: Position at National Central University of Taiwan NATIONAL CENTRAL UNIVERSITY, TAIWAN, R.O.C. Department of Mathematics The Department of Mathematics at the National Central University in Taiwan invites applications for tenure track or visiting positions beginning in Fall, 1992. Numerical analysts are specially welcome. Currently we have only two levels of professorship: associated and full. Teaching load is usually 7 hours per week, including 4 hours of calculus. Minimum qualifications are a Ph.D. in Mathematical Sciences, and a strong commitment to teaching and research. The department now has 22 faculty members, around 200 under- graduate and 30 graduate sutdents. We offer B.S., M.S. and Ph.D. degrees in Mathematics. Starting salary for Associated Professors is about NT$850,000 per year for the first two years. The currency exchange rate today is US:NT = 1:24.74. For a middle class citizen like us the tax rate is around 10%. Math Department has a VAX 6510 and a micro VAS 3900, running VMS; and an expanding network of DECstation 5000-series, running Ultrix. IBM PC clones are common here. Every faculty member has one. Virtually all computing facilities in Taiwan are connected by telnet. You have a good chance to find the the exact machine you like. But it may take you some efforts to setup a software working environment. Applications will be evaluated beginning early April. Send vitae, transcripts and three letters of reference to the following address. Since it is not easy to have an interview, a copy of the draft of your Ph.D. thesis and/or other publications will be much helpful. For further information, contact me (Shann) by e-mail: t210001@sparc20.ncu.edu.tw Prof. Hua Yang, Chairman Department of Mathematics National Central University Chung Li, Taiwan R. O. C. email: NCUT010@TWNMOE10.BITNET tel: 011-886-3-426-7209, 011-886-3-425-6704 FAX: 011-886-3-425-7379 ------------------------------ From: George Labahn Date: Fri, 7 Feb 92 13:22:57 -0500 Subject: Report on Extrapolation and Rational Approximation meeting A Report on the International Congress on Extrapolation and Rational Interpolation held on Jan 13-17, 1992 Tenerife, Canary Islands, Spain The International Congress on Extrapolation and Rational Interpolation was held this year on the island of Tenerife in the Canary Islands of Spain. The four day conference was the latest in a series of such congress's, the previous one being in Luminy, France in 1989. The conference was organized by C. Brezinski of University of Lille, France and N. Hayek, P. Gonzalez-Vera, F. Perez-Acosta, C. Gonzalez-Concepcion, M. Camacho, J. Betancor and M. Jimenez from the University of La Laguna, Spain. Participants included researchers from around the world - Australia, Belgium, Canada, England, Finland, France, Germany, Israel, Italy, Japan, Norway, Poland, Portugal, Romania, Russia, Scotland, South Africa, Spain, Sweden, Switerland, the Netherlands and the US. The conference was great - good talks, great location and fine treatment for all the participants. The conference was organized into five plenary talks along with approximately 70 short (~30 min.) talks given in two parallel sessions. The conference began bright and early on Monday the 13-th with the first of the plenary talks - this one by Gene Golub entitled 'Generating unknown orthogonal polynomials from known orthogonal polynomials'. His talk (parts of which were based on some recent joint work with Bernd Fischer of Hamburg) centered around some problems in least squares approximation. In particular a description was given of the problem of efficiently generating new orthogonal polynomials from old when additional points are to be included with the previous set of approximation points. The technique used, that of modified moments, was also shown to lead to solutions of other problems, including for example Gaussian quadrature rules for integrals having singularities near the endpoints of the interval of integration. The other plenary talk on the first day was given in the afternoon by Philip Rabinowitz from the Weizmann Institute of Science in Israel. Entitled Extrapolation methods in Numerical Integration, the talk gave a survey of the progress made since 1971 in using various extrapolation methods in solving numerical integration problems. Included were methods dealing with singular integrands and evaluation of highly oscillatory infinite integrals Besides the plenary talks, the highlight of the first days talks came immediately after Gene Golubs talk. Claude Brezinski presented a light talk detailing a little of the history of some of the leaders in the fields of extrapolation and rational approximation . The talk included a mini-album of photos of such past luminaries as Hermite and Pade. Since some of the photos were on the fun side, Brezinski felt compelled to include one or two photos of himself in equally embarrassing poses - including one that probably caught him viewing his first UFO. He also mentioned that, when he first approached the descendants of Pade during the research for his book on Pade, they were most surprised by the interest - they had no idea that their grandfather was anybody famous. Additional plenary talks were given on the Tuesday and Thursday. Martin Gutknecht from ETH in Zurich gave an interesting talk discussing a new Pade algorithm discovered by two Canadians, Stan Cabay and Ron Meleshko. The main feature of their algorithm is that it is the first known fast numerically (weakly) stable Pade algorithm. The algorithm also provides a fast stable algorithm for inverting Hankel and Toeplitz matrices. Gutknecht surveyed the various approaches used in both Pade computation and stable methods for Toeplitz inversion and gave some idea of how Cabay and Meleshko accomplished their results. Finally Gutknecht gave some conjectures and details on how their approach can be used to establish stable algorithms in other related fields such as rational interpolation and alternate Pade algorithms. He also highlighted the relation of their stable algorithm to the non-symmetric Lanczos process. The second plenary talk of this day was a talk by Daniel Bessis from France. Titled the ''Moment Problem Formulation of the Schrodinger Equation'', Bessis showed how to determine in an exact manner the lowest eigenstate of Schrodinger equations. In particular he showed how one can replace the full Schrodinger equation by a moment problem and obtain the desired information about this lowest eigenstate. The talk was well received and generated a number of interesting discussions during the rest of the conference. The next day was an off day for the conference. The organizers were kind enough to provide the conference attendees a bus tour of Teide, the famous volcano of the island. Lots of conversation and scenic sights - the terrain of the island seemed to change every ten kilometers - sometimes looking like the forests of Canada while at other times like a magazine pictorial of New Mexico. The fourth day of the conference featured the final plenary talk of the conference given by Avram Sidi of the Technion in Israel - ''Rational Approximation from power series of vector-valued meromorphic functions and their applications of the matrix eigenvalue problem". The talk developed vector-valued rational approximation procedures for a vector-valued function via applying vector extrapolation methods to the sequence of partial sums of the corresponding Taylor series. The talk included discussions of convergence and results on poles. Generalizations of the work were given that impacted on the finding of largest distinct eigenvalues and eigenvectors of certain matrices. The end of the talk featured a lively discussion between the speaker and Gene Golub - a discussion that continued into the next day at lunch. Finally a special thanks from the speaker was given to Wolfgang Throns daughter, a new MD of approximately 14 days standing, who helped the speaker recover from loosing his voice just 24 hours previously. The rest of the conference was filled by the short talks and lots of social events. Examples included an energetic and easily understood talk by Bernhard Beckermann discussing a crossrule for rational interpolation; a clear presentation by Ana Cristina Matos on some acceleration properties for the vector epsilon algorithm for a pair of families of vector sequences; some interesting results from Peter Graves-Morris on the use of functional Pade approximants for solving integral equations (main memory - doesn't always work well, unfortunately); a talk by Jeanette Van Iseghem on best choice of poles for certain Pade approximants ( main memory - no fun to study this problem - even the easy case is real hard ); a description of a general way to construct lots of Pade-like approximants by Marc Van Barel and Ademar Bultheel; and lots and lots more that should also be mentioned (no ranking is implied above - just some that I remember for one reason or other). Some attendees reminded me of the talk by Jose Javier Martinez, who appears to have a reputation for lots of humour in his talks - enough to worry his supervisor and coauthor about what he would say during his 30 minutes of prime time. Still others mentioned the talks from the large contingent of researchers (+ 1 new medical doctor) that came from Colorado. Of course the conference was much more than just the talks. There was a three hour break every afternoon. This enabled some participants to catch up with their work (well okay I admit I only saw one person do this) - others swam or worked on their tans beside the pool. The participants were treated to wonderful meals every evening. Lots of people continued to compare ideas well into the late evening (I learned that my new Spanish and Portugese friends could give very lucid talks in English, translating very complex ideas from their language into mine. Yet somehow the phrase ''please, its after 2am and I need to get some sleep before tomorrows first talk at 9'' could not be translated into their home languages). North Americans also had to get used to late dining. This was especially evident on the first night - participants boarded a bus for the restaurant at 7pm - only to find that the bus ride was to last two hours. After one hour one was barely able to hear the roar of the bus engine over the stomach rumbling noises coming from the assembled gathering. Lots of participants had chocolate bars or apples at the ready for a 5 pm snack on the next day. The highlight of the social activities occurred on the Thursday evening when the participants were wined and dined at the Casino Taoro. A great meal including lots of little elegant touches - menus specially engraved for the conference, cigars and flowers handed out after the meal, a local folk band invited to entertain at the end of the evening. Memories of the meal included: Claude Brezinski and Michela Redivo Zaglia dancing a wild and impressive flamengo; about half the crowd joining hands into long lines to dancing some sort of a snake-like dance throughout the tables (watching 40 academics dance as one is usually not anyones idea of fun - but this was something truly different); Gene Golub bouncing up and down during another dance; Carsten Carstensen deciding that sipping wine was a good technique for countering any nearby odor of cigarette smoke (which he disliked) - not a good decision considering the cigar giveaway; the folk group loving serenading Ana Cristina Matos with a Portugese love song. Afterwards many of the conference attendees went up to do a little gambling in the casino itself. Memories here include: George Labahn loosing money (it's my memory); Zelia Da Roche winning at the slot machines (main technique - only use one slot machine until one wins big - then move to another one immediately. Made no sense but it did work for her); Marc Van Barel doubling his salary when one of his numbers came in at the roulette wheel; most conference people watching not gambling (these were, after all, smart people). I do not know if the above description sounds appealing or just silly - I do know that for me it was a wonderful conference and I would love to go again for both people reasons and academic reasons. I look forward to attending the next such conference. George Labahn (with help from Gene Golub and Ana Matos) Symbolic Computation Group University of Waterloo, Waterloo, Canada glabahn@daisy.waterloo.edu ------------------------------ End of NA Digest ************************** -------