From na-net@na-net.stanford.edu Sun Jul 9 17:08:54 1989 Received: from beauty.stanford.edu by antares.mcs.anl.gov (4.0/SMI-DDN) id AA27083; Sun, 9 Jul 89 17:07:02 CDT Received: from patience.stanford.edu by beauty.stanford.edu (4.0/inc-1.5) id AA22395; Sun, 9 Jul 89 15:12:49 PDT Received: from bravery.stanford.edu by patience.stanford.edu (4.0/inc-1.5) id AA15872; Sun, 9 Jul 89 15:10:12 PDT Received: by bravery.stanford.edu (4.0/inc-1.5) id AA12749; Sun, 9 Jul 89 15:09:59 PDT Date: Sun, 9 Jul 89 15:09:59 PDT From: na-net@na-net.stanford.edu Message-Id: <8907092209.AA12749@bravery.stanford.edu> Return-Path: Subject: NA-NET distribution message Errors-To: nanet@na-net.stanford.edu Maint-Path: maintainer@na-net.stanford.edu To: na-net@na-net.stanford.edu Reply-To: na-net@na-net.stanford.edu Comment: requests, comments or problems to nanet@na-net.stanford.edu Comment: submissions to na@na-net.stanford.edu Comment: alternate address: na%na-net@score.stanford.edu Status: R NA Digest Sunday, July 9, 1989 Volume 89 : Issue 26 Today's Editor: Cleve Moler Today's Topics: SIAM Conference on Geometric Design Argonne Summer Institute in Parallel Processing NAG's Multigrid Routine max x'Ax+b'x Colloquium on Applications of Mathematics in Hamburg Updates to NA-NET Mailing List New Position for Dongarra Fellowship at John von Neumann Supercomputer Center NAG Optimization with Discontinuous Derivatives Scaling of Condition Number with Resolution Professorship in Norway Address Change for Arnold Neumaier ------------------------------------------------------- From: Michelle Jones Date: Mon, 26 Jun 89 14:42 EDT Subject: SIAM Conference on Geometric Design TO: NA NET FROM: Michelle Jones, Marketing Manager, SIAM SUBJECT: Announcement -- SIAM Conference on Geometric Design DATE: November 6-10, 1989 TITLE: SIAM Conference on Geometric Design ORGANIZER: Robert E. Barnhill Arizona State University PLACE: Sheraton Mission Palms Hotel Tempe, Arizona TOPICS: Teleological modeling, computer graphics, parametric curves and surfaces in CAGD, images of matrices, domain processing and manipulation, surface fitting and other related subjects. INVITED SPEAKERS: Alan Barr, California Institute of Technology, Teleological modeling: A New Approach for Representing Objects Philip J. Davis, Brown University, The Decline and Renaissanc of Geometry Rida Farouki, IBM, Numerical Stability of Geometric Algorithms and Representations David Gossard, Massachusetts Institute of Technology, Geometry in Conceptual Design Gerald Farin, Arizona State University, NURBS: Theoretical and Practical Issues John Gregory, Brunel University, Parametric Curves and Surfaces in Computer-Aided Geometric Design Cleve Moler, Ardent Computer Corporation, Images of Matrices -- Mathematical Visualization John Rice, Purdue University, Using Domain Processing for Solid Modeling Tom Sederberg, Brigham Young University, Algorithms for Computing Intersections of Parametric Surface Peter Wilson, Rensselaer Design Research Center, Geometric Aspects of PDEs Mike Wozny, Rensselaer Polytechnic Institute, Visualization? Or Merely Geometry and Computer Graphics. CONTACT: SIAM Conference Coordinator 117 S. 17th Street, 14th Floor Philadelphia, PA 19103-5052 USA 215-564-2929 (FAX) 215-564-4174 E-Mail: siam@wharton.upenn.edu ------------------------------ From: Jack Dongarra Date: Fri, 30 Jun 89 10:31:20 CDT Subject: Argonne Summer Institute in Parallel Processing SUMMER INSTITUTE IN PARALLEL COMPUTING A Two-Week Institute at the Advanced Computing Research Facility Mathematics and Computer Science Division Argonne National Laboratory September 5-15, 1989 Summer Institute Faculty Computer Facilities Don Austin, DOE ALLIANT FX/8 (8 processors) Mani Chandy, CALTECH AMT DAP (1024 processors) Tom DeFanti, U. OF ILLINOIS, CHICAGO ARDENT Titan (4 processors) David Gelernter, YALE UNIVERSITY BBN Butterfly GP1000 (96 processors) John Gurd, UNIV. OF MANCHESTER, U.K. BBN Butterfly II (45 processors) Ken Kennedy, RICE UNIVERSITY ENCORE MULTIMAX (20 processors) Alex Nicholau, U.. OF CALIF.,IRVINE INTEL iPSC HYPERCUBE (32 processors) Burton Smith, TERA COMPUTER INTEL iPSC HYPERCUBE (16 processors, Guy Steele, THINKING MACHINES with vector capability) ARGONNE STAFF SEQUENT BALANCE (24 processors) STELLAR GS1000 THINKING MACHINES CM-2 (16,384 processors) Eligibility and Selection Criteria: Institute limited to 25 graduate students and postdoctoral researchers. Preference given to those likely to advance parallel computing research. Only one person from the same institution and department accepted. Applications due July 15, 1989, supported by a letter of recommendation. Note: Participants will receive free lodging for September 5-15 and a stipend for meals and incidental expenses. Travel costs will be reimbursed up to $750. For further information, write or call: Teri Huml Mathematics and Computer Science Division Argonne National Laboratory Argonne, Illinois 60439-4844 312-972-7163 huml@mcs.anl.gov The Institute is supported by the National Science Foundation Science and Technology Center for Research on Parallel Computing and by the U.S. Department of Energy ------------------------------ From: Wlodek Proskurowski Date: Fri, 30 Jun 1989 12:25:37 PDT Subject: NAG's Multigrid Routine This spring I gave the following problem as a part of the take home quiz to my graduate class in numerical PDEs: The NAG software package contains a multigrid routine (D03EEF) for solving general 2nd order elliptic PDEs on rectangular regions. It has two options for approximating first derivatives by using a) central, or b) forward differences. The following test example (from p.8 of the Mark 13 Release NAG Manual) was run on the SUN computer in double precision: -Du+100(u_x+u_y)=f in [0,1]^2 with Dirichlet boundary conditions corresponding to the exact solution u=x^2+y^2. Here D denotes the Laplacian, and u_x partial wrt x. The obtained results were: # of levels # of iterations ||erorr||_2 a) b) a) b) 3 33 7 5e-11 4.0e-2 4 14 8 3e-12 1.6e-2 5 9 8 7e-13 3.0e-3 Explain the behavior of the rate of convergence and the error as a function of N=2^(#of levels) in both cases. Why such extreme differences in the results occur (note that the method is implemented correctly and there are no bugs in the program)? Comments and questions to NAG. 1. Only the result for 3 levels is given in the manual. Moreover, given there are actually squares of the 2-norm (additionally, without normalization), so the numbers read: a) 1.7e-19 and b) 1.28e-1. 2. Who cursorily looking at these rusults would want to use the routine: one option is super accurate but extremely expensive, the other fast but gives practically no useful information (compare with the norm of the solution!) 3. I hope you want NAG to be used not only by numerical analysts who have time to invest (or students to do the work) to find out that the routine works well only the test example is ill chosen, especially in the complete absence of proper explanations. ------------------------------ From: John Conroy Date: 30 Jun 89 22:43:19 GMT Subject: max x'Ax+b'x I am interested in solving the following problem: max x'Ax+b'x ||x||2=1 where A is a symmetric n by n matrix and || ||2 is the 2-norm. When b=0, the solution is simply the eigenvector corresponding to the maximal eigenvalue. If the 2-norm is replaced with linear constraints and/or equalities, its a quadratic programming problem. However, as stated above the best I know is to attack it as a non-linear constrained optimization problem, which seems like overkill to me. Any pointers or suggestions? John Conroy Supercomputing Research Center, Lanham, MD ------------------------------ From: Bernd Fischer Date: Wed, 5 Jul 89 12:23:16 PDT Subject: Colloquium on Applications of Mathematics in Hamburg First Announcement International Colloquium on Applications of Mathematics on July 6 and 7, 1990 in Hamburg The Institute of Applied Mathematics of the University of Hamburg will hold an international Colloquium on Applications of Mathematics on the occasion of the 80th birthday of Lothar COLLATZ. Invitations for a main lecture have been accepted by: Ph. Ciarlet (Paris), D. Gaier(Giessen) R. B. Guenther(Corvallis), W. C. Rheinboldt(Pittsburgh). Short lectures (ca. 15 minutes duration) connected with the topic of the Colloquium are welcome from everybody interested, subject to space and time restrictions. Participants from East and Southeast Europe con possibly be given some support for local expenses. Those who may wish to participate in the above mentioned Colloquium and want to receive further information are requested to send a note as soon as possible, but not later than December 15, 1989 to University of Hamburg Institute of Applied Mathematics Bundesstrasse 55 D-2000 Hamburg 13 West Germany ------------------------------ From: Mark Kent Date: Thu, 6 Jul 89 09:22:26 PDT Subject: Updates to NA-NET Mailing List Updates to the NA-NET mailing list are as follows. Changes: randolph bank to rbank@ucsd.edu petter bjorstad to petter@eik.ii.uib.no theodorus dekker to dirk@fwi.uva.nl eva edberg to evaedb%folke.se@majestix.ida.liu.se sylvan elhay to elhay@cs.ua.oz.au john gilbert to john@eik.ii.uib.no ivan graham to igg@maths.bath.ac.uk malvin kalos to kalos@tcgould.tn.cornell.edu jerry kautsky to j.kautsky@research.cc.flinders.oz.au richard liu to liu@mssun7.msi.cornell.edu paul muir to muir@husky1.stmarys.ca roy nicolaides to rn0m@andrew.cmu.edu takashi nodera to nodera@math.keio.ac.jp yoshio oyanagi to oyanagi@is.tsukuba.ac.jp louise perkins to perkins@lll-crg.llnl.gov david ryan to dmryan@cs.cornell.edu alastair spence to as@maths.bath.ac.uk grace wahba to wahba@stat.wisc.edu pieter wesseling to piet%dutinfh@uunet.uu.net hongyuan zha to prlb2!kulcs!kulesat!zha@uunet.uu.net New entries: roberto ansaloni acray2%icineca2.bitnet@forsythe.stanford.edu jarle berntsen jarle@eik.ii.uib.no margaret cheney cheneym@turing.cs.rpi.edu shenaz choudhury sc7@vms.cis.pittsburgh.edu brian coomes coomes%csfsa.cs.umn.edu@umn-cs.cs.umn.edu tim davis davis@uicsrd.csrd.uiuc.edu peter derijk actrijp@hutruu0.bitnet@xxx julio dix jd01%swtexas.bitnet@forsythe.stanford.edu david dobson dobson@rice.edu henry ellingworth himen%ecs.oxford.ac.uk raffael eperego perego%icnucevm.bitnet@forsythe.stanford.edu stein eriksen stein@eik.ii.uib.no jesper fabricius unijf%neuvm1.bitnet@forsythe.stanford.edu anders forsgren andersf@math.kth.se marco frontini marfro@ipmma1.polimi.it albert gilg zeus@ztivax.siemens.com linitial ginitial lg04c7%swtexas.bitnet@forsythe.stanford.edu walter hoffman walter@fwi.uva.nl doug james doug@mathel.ncsu.edu tom kirke u15305%uicvm.bitnet@forsythe.stanford.edu jian le jian@eeg.com rob leland leland%na.oxford.ac.uk alain leroux leroux%frbdx11.bitnet@forsythe.stanford.edu fx litt litt%bliulg11.bitnet@forsythe.stanford.edu christian lubich c80427%ainuni01.bitnet@forsythe.stanford.edu herbert muthsam a8131daa%awiuni11.bitnet@forsythe.stanford.edu marcus naraidoo ma_mn@cms.bristol.ac.uk makoto natori natori%gama.is.tsukuba.junet@relay.cc.u-tokyo.ac.jp lois petherick lmp%myrias.uucp@relay.cs.net pia pfluger pia@fwi.uva.nl shirley pomeranz pomeranz@tusun2.knet.utulsa.edu ekkehard sachs tfb403%dkluni01.bitnet@forsythe.stanford.edu antonia vecchio iam@areana.na.cnr.it david watkins watkins%wsumath.bitnet@forsythe.stanford.edu harry yserentant uma005%ddohrz11.bitnet@forsythe.stanford.edu - Mark ------------------------------ From: Jack Dongarra Date: Thu, 6 Jul 89 17:25:21 CDT Subject: New Position for Dongarra After a rewarding 16 year association with Argonne National Laboratory I have accepted a position at the University of Tennessee and Oak Ridge National Laboratory as a professor in the Computer Science Department and a member of the Mathematical Science group at Oak Ridge. I will move from Illinois to Tennessee during the first week of September. I look forward to the challenges and opportunities of this new position as well as my continued involvement with such projects as LAPACK, netlib, the "LINPACK Benchmark" and others from Tennessee. Jack Dongarra ------------------------------ From: Hilde Devoghel Date: Thu, 6 Jul 89 16:32:39 PDT Subject: Fellowship at John von Neumann Supercomputer Center Postdoctoral fellowship for 1989-1990 at John von Neumann National Supercomputer Center, PO Box 3717, Princeton, NJ 08543, in NSF funded project involving special functions of mathematical physics, acceleration techniques for slowly convergent series, numerical quadrature and multivariate interpolation, in a supercomputing environment. Contact: Professor Michael P. Barnett at JvNC, bitnet address MBARNETT@JVNCD. ------------------------------ From: Philip Gill Date: Fri, 7 Jul 89 15:00 GMT Subject: NAG Optimization with Discontinuous Derivatives The last NA-Net distribution contained a message from DeKnuydt and Smolders concerning the use of the Nag library to minimize the function: function_result = - SUM [N(i)/N] * blog [(N(i)/N)] all i with N(i) <> 0 where N(i) = number of occurrences of value i N = total number of occurrences. The Nag routines E04JAF, E04JBF and E04VCF discussed by DeKnuydt and Smolders are designed for smooth nonlinear optimization---i.e., they can be expected to work only when the first and second derivatives of the objective function exist and are continuous. The problem described above does not fall into this category. The NAG routine E04CCF, based on the Nelder and Mead polytope method, is intended for problems whose derivatives are discontinuous. Philip Gill Mathematics Department, UCSD. ------------------------------ From: Henry Greenside Date: 7 Jul 89 18:46:25 GMT Subject: Scaling of Condition Number with Resolution Can people suggest any references or proofs about the relationship between the condition number of a matrix obtained by discretizing an elliptic pde and the order of accuracy of the discretization? It seems commonly known that second-order accurate finite difference approximations to elliptic operators, e.g., (d^2 f(x) / Dx^2), lead to matrices with condition numbers that scale as nx^2, i.e., quadratically with the number of uniform mesh points. Similarly, it seems well known that matrices arising from Chebyshev spectral expansions of such operators scale as nx^4, as a fourth power. Have analyses been made about how general this is, e.g., for more general operators: d/dx( a(x) df(x)/dx ) or how boundary conditions affect this scaling? If there is interest, I will summarize replies to the net. ------------------------------ From: Petter Bjorstad Date: Sat, 8 Jul 89 17:47:05 +0200 Subject: Professorship in Norway Professor in Computer Science The Department of Computer Science, University of Bergen requests applications for a tenured position as Full Professor of Computer Science, (Scientific Computing / Optimization) for immediate consideration. The department has 12 full time faculty members (6 full professors and 6 associate positions), 2 adjoint (part-time) professors, 14 research fellowships (Ph.D. students). and 45 Master degree students. The department gives courses for undergraduate as well as graduate studies. There are two main directions of study at the advanced level, {computer science} and {scientific computing, (numerical analysis and optimization)}. This position will have a special responsibility within the "Scientific Computing" direction of study. All faculty members have state of art workstations (SUN-3 or newer), the computing environment is based on an ethernet network directly connected to the international Internet (ARPA-Net). The department has created a laboratory for parallel processing (Alliant FX/8 and Intel Hypercubes) jointly with the CMI research institute, and also a laboratory for AI research. The department moved into a new building (The High-Tech Center of Bergen) in the spring of 1989. Several other computer science related research groups, including IBMs Scientific Center are located in the same building. The Department conducts research in the following areas: In computer science: Analysis of Algorithms, Datacommunication and Coding Theory, Artificial Intelligence, Programming Development (Languages, specifications, verifications and environments). In scientific computing: Numerical Integration, Numerical solution of Partial Differential Equations, Accelleration of Convergence, Discrete and Continuous Optimization. There is a strong focus on the use of parallel computers in all areas of research. The department has both national and international cooperations with research groups at other institutions (In particular in the United States and Europe). Locally, we cooperate with the Christian Michelsen Research Institute and with the IBM Nergen Scientific Center. There are also other groups within the university doing computer science or computer science related work. (Computer Science in Social Sciences, Computer Lingvistics and Computer Psychology) Prospective applicants should be able to teach in the department, and must have an outstanding research record in numerical analysis/optimization. A documented interest in aspects of such research related to parallel computer systems will be especially welcomed. For more information on how to apply, please drop an E-mail note to: petter@eik.ii.uib.no or na.bjorstad@na-net.stanford.edu OR write to: Institutt for Informatikk Thormohlens gate 55 N-5008 BERGEN NORWAY ------------------------------ From: Arnold Neumaier Date: Sat, 8 Jul 89 16:23:40 cdt Subject: Address Change for Arnold Neumaier Next Tuesday I'll return to Germany. My new address is Prof. Dr. Arnold Neumaier Inst. f. Angewandte Mathematik Universitaet Freiburg Hermann-Herder-Str. 10 D-7800 Freiburg West Germany My email address is neum%sun1.ruf.uni-freiburg.dbp.de@relay.cs.net ------------------------------ End of NA Digest ************************** -------