**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 <SIAM@wharton.upenn.edu>

Date: Mon, 26 Jun 89 14:42 EDT

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 <dongarra@antares.mcs.anl.gov>

Date: Fri, 30 Jun 89 10:31:20 CDT

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 <proskuro%castor.usc.edu@usc.edu>

Date: Fri, 30 Jun 1989 12:25:37 PDT

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 <conroy@super.org>

Date: 30 Jun 89 22:43:19 GMT

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 <fischer@na-net.stanford.edu>

Date: Wed, 5 Jul 89 12:23:16 PDT

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 <kent@na-net.stanford.edu>

Date: Thu, 6 Jul 89 09:22:26 PDT

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 <dongarra@antares.mcs.anl.gov>

Date: Thu, 6 Jul 89 17:25:21 CDT

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 <hilde@na-net.stanford.edu>

Date: Thu, 6 Jul 89 16:32:39 PDT

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 <SVEN%vax.num-alg-grp.co.uk@nsfnet-relay.ac.uk>

Date: Fri, 7 Jul 89 15:00 GMT

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 <romeo!hsg@cs.duke.edu>

Date: 7 Jul 89 18:46:25 GMT

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 <petter@eik.II.UIB.NO>

Date: Sat, 8 Jul 89 17:47:05 +0200

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 <neumaier@math.wisc.edu>

Date: Sat, 8 Jul 89 16:23:40 cdt

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

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