NA Digest Sunday, September 8, 1991 Volume 91 : Issue 36

Today's Editor: Cleve Moler

Today's Topics:

Submissions for NA Digest:

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Information about NA-NET:

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From: Gene Golub <golub@Cholesky.Stanford.EDU>
Date: Mon, 2 Sep 91 18:58:25 PDT
Subject: Can you be "fingered"?

In the last several months, I have noticed that it is not possible to "finger"
persons at some .com organizations, eg. NEC, AT&T, SGI and some educational
institutions, too. It was possible to finger persons at these institutions in
the past. I think this practice of disabling the finger command is very bad in
the modern age of computer communication.

I have read the book, "Cuckoo's Egg" which described how systems can
be broken into via the finger command. But I would hope this glitch in
the unix system could be eliminated by the system staff.

Why is fingering important? I find it useful to find out if someone has read
their mail of late. Than too many of us have information such as our phone
numbers, FAX numbers and mail addresses in our .plan file. So a lot of helpful
and useful information can be obtained by using the finger command.
(Try finger as an example.)

I realize many people are worried about providing such information but
that should be their decision, not the systems administrator. (By the
way, I heard on "All things considered" today that 30% of the
Libertarian Party are "computer people".)

So if you feel similar to me, please complain to your systems person or
whomever has made this decision. It helps us all.



From: Philip Sharp <>
Date: Wed, 4 Sep 1991 18:31:36 -0400
Subject: Retarded Differential Equations

I am collecting practical examples of retarded differential equations. If
you have examples, I would appreciate a reference to or description of
them. I am particularly interested in examples with multiple lags or that
have at least five equations.

I plan to make the collection publicly available.

Thank you.

Philip Sharp
Department of Mathematics and Statistics
Queen's University
Kingston, K7L 3N6

Tel: (613) 545 2391
Fax: (613) 545 2964


From: Fred Kus <FRED@SSCvax.CIS.McMaster.CA>
Date: Thu, 5 Sep 1991 13:05:00 -0400
Subject: Hyperbolic PDEs


Does anyone have, or know where I could get, any public domain
software for hyperbolic PDEs in 1, 2 or 3 space dimensions. I
an particularly interested in codes for advective-diffusion


Fred W. Kus INTERNET: fred@SSCvax.CIS.McMaster.CA
Computing & Information BITNET: fred@MCMASTER.BITNET
Services PHONE: (416) 525-9140 ext.4160
Mcmaster University FAX (416) 528-3773
Hamilton, Canada L8S 4K1


From: F. W. Olver <>
Date: Thu, 5 Sep 91 14:07:32 EDT
Subject: SLI vs Floating-point

Daniel Lozier, Peter Turner & I appreciate David Goldberg's reference to
Jim Demmel's critical article in the Proceedings of the Eighth Symposium
on Computer Arithmetic, 1987. This article is in fact mentioned in the
second reference that we supplied in our original letter to the Digest,
and also in more recent papers, for example, SIAM J. Numer. Anal.,v.27,
pp.1295-1304,1990. The arguments advanced by Demmel concerning precision
in the SLI system resemble those that were made by fixed-point advocates
at the time the floating-point system was under consideration. By
analogy, we may expect that the final resolution of these arguments awaits
the construction and extensive use of SLI hardware, followed by the
further development of error analyses that apply directly to the SLI

Frank Olver


From: Stanley Osher <>
Date: Tue, 3 Sep 91 08:07:09 -0700
Subject: Position Available in Santa Monica

Small, rapidly growing image processing company in Santa Monica,
Ca. seeks Phd. or Master's level people. Should be an excellent
programmer with a strong background in numerical analysis, scientific
computing, partial differential equations and image processing. Please
fax your resume to 213-396-5208, or mail it to 2800-28th St, suite 101,
Santa Monica, Ca. 90405

Stan Osher


From: M Berzins <>
Date: Thu, 5 Sep 91 12:23:03 BST
Subject: Position Available at Leeds

Vacant Position in Parallel Scientific Computation.

Postdoctoral Resaerch Fellow in
Parallel Computing (Domain Decomposition).

A two year post available in the School of
Computer Studies Leeds University U.K. to
work on domain decomposition techniques
for the solution of time-dependent p.d.e.s.

The post is available now, standard UK academic
salary applies, informal enquiries
to Dr Martin Berzins, Computer Studies,
Leeds University, LEEDS LS@ 9JT, U.K.


From: John N. Shadid <>
Date: Thu, 5 Sep 91 08:33:58 MDT
Subject: Research Fellowships at Sandia, Albuquerque

Sandia National Laboratories invites applications and nominations of
outstanding engineers and scientists for its 1992 Research Fellowships
in the Computational Sciences.

The Sandia Research fellowships will provide an exceptional opportunity
for engineers and scientists performing leading-edge research in the
computational sciences. This year the fellowships will be awarded in the
field of computational fluid dynamics (CFD). Areas of interest include;
large-scale simulation of incompressible fluid flow, computation of complex
chemically reacting flow systems and numerical simulation of oceanic and
atmospheric flows as applied to global climate modeling. In addition to the
fellowships, several post-docs will also be offered.

Sandia's Mathematics and Computational Science Department maintains strong
programs in CFD, computational physics and engineering, analytical and
computational mathematics, advanced computational approaches for parallel
computers and scientific visualization. Sandia provides a unique parallel
computing environment, including a 1024-processor nCUBE 3200 hypercube, a
1024-processor nCUBE 6400 hypercube, a Connection Machine CM-2X, a 64
processor Intel iPSC 860, and several large Cray supercomputers. The
successful candidate must be a U.S. citizen, must have an earned doctorate
in the sciences, and should have made a strong contribution in CFD or
related fields.

The fellowship appointment is for a period of one year, and may be renewed
for a second year. It includes a highly competitive salary, moving expenses,
and a generous professional travel allowance. Applications from qualified
candidates, or nominations for the fellowships, should be addressed to
Sudip Dosanjh, Supervisor Parallel Computational Science Division 1421,
Sandia National Laboratories, PO Box 5800, Albuquerque, NM 87185.
Applications should include a resume, a statement of research goals, and
the names of three references. The closing date for applications is
November 30, 1991. The positions will commence during 1992.

John Shadid
Sandia Nat. Labs.
Albuquerque, NM 87185
(505) 844 - 5621


From: Daniel Szyld <>
Date: Sun, 01 Sep 91 10:29:56 IST
Subject: AMS Session on Numerical Linear Algebra

There will be a Special Session on Numerical Linear Algebra at
the American Mathematical Society (AMS) meeting 868, in Philadelphia,
October 12-13, 1991. Listed below are the speakers and the title
of their presentations. Abstracts of these talks will appear in the
Abstracts of the AMS before the conference. Further information,
including hotel information and travel directions can be found in the
Notices of the AMS. You can also contact the session organizer:
Daniel B Szyld, Department of Mathematics, Temple University 038-16,
Philadelphia, PA 19122-2585, e-mail :

Jesse L. Barlow Error Analysis of Update Methods for the Symmetric
Eigenvalue Problem
Ralph Byers Numerical Computation of an Analytic Singular
Value Decomposition of a Matrix Valued Function
Howard Elman Parallel Implementation of the hp-version of the
Finite Element Method on a Shared-Memory Architecture
Anne Greenbaum Laplace's Equation and the Dirichlet-Neumann Map
in Multiply Connected Domains
Linda Kaufman Modifying the Shougen-Shuqin algorithm for the banded
Symmetric Generalized Matrix Eigenvalue Problem
Ivo Marek Convergent Iterative Methods to Find Stationary
Distribution of Markov Processes
Carl D Meyer Errors in Aggregadtion/disaggregation for Markov Chains
Michael Neumann Asynchronous parallel iterations for nonlinear systems
Michael Overton On the Convex Hull of Projection Matrices
Ricardo Pantazis Parallel Solution of Generalized Band Symmetric
Eigenvalue Problems by Sectioning
Mordukh Primak A projection cutting plane algorithm for convex
programming problems
Lothar Reichel A new implementation of the GMRES method
G.W. Stewart Updatable, Rank-Revealing Decompositions
William Stewart SOR for Markov Chains Problems
Gilbert Strang Joint Stability of Two Matrices and their Joint
Spectral Radius
L. N. Trefethen Eigenvalues and pseudo-eigenvalues of nonsymmetric
random matrices
Olof B. Widlund Some Recent Results on Schwarz Type Domain
Decomposition Algorithms


Sender: Heinz W. Engl <K310773%ALIJKU11@CUNYVM.CUNY.EDU>
Date: Wed, 04 Sep 91 09:37:48 SDT
Subject: Contents: Surveys on Mathematics for Industry

Surveys on Mathematics for Industry, Vol.1 No.2, Contents:

C.Cercignani, Mathematical models in rarefied gas dynamics

D.Hartmann, G.Kern, Wind-induced vibrations on high-voltage overhead lines

Subscription information and inspection copies:
Springer Verlag
POBox 89
A-1201 Vienna, Austria

Substantially reduced personal subscriptions for members of:
- Japanese SIAM
- OeMG

Inquire with your society!

Heinz W. Engl, Linz (Managing Editor)


Date: Wed, 4 Sep 91 09:55:46 -0400
Subject: Symposium in Greece on Method of Lines


First International Symposium
Methods of Lines, Surfaces and Dimensional Reductional
in Computational Mathematics and Mechanics

November 12-16, 1991
University of Athens, Greece.

J.H. Argyris (Germany), I. Babushka (USA), A. Bacopoulos (Greece),
M. Baines (UK), M. Berzins (UK), Ph. Ciarlet (France),
Y.K. Cheung (Hong Kong), C. Dafermos (USA), P. Deuflhard (Germany),
I.St. Doltsinis (Germany), V.A. Dougalis (Greece), I.S. Duff (UK),
I. Farago (Hungary), J.E. Flaherty (USA), D.G. Gordeziani (USSR),
Ya. M. Grigorenko (USSR), P.J. van der Houwen (NL), J.M. Hyman (USA),
C. Johnson (Sweden), I. Kevrekidis (USA), J.L. Lions (France),
G.I. Marchuk (USSR), T. Miyoshi (Japan), G.C. Papanicolaou (USA),
L.R. Petzold (USA), O. Pironneau (France), A. Quarteroni (Italy),
J.I. Ramos (USA), N. Satofuka (Japan), C. Schwab (USA),
R. Temam (France), L. Turchak (USSR), L.R.Volevich (USSR),
L.S. Xanthis (UK).


The symposium will be held in Athens and Ancient Olympia.
It is organised by the University of Athens, Greece, and
the Sir George Cayley Institute - Polytechnic of Central London, England.

The theme of the symposium focuses on various semi-discrete,
semi-analytic or discrete dimensional reduction methodologies,
e.g. methods of lines, finite strips, finite volume, inertial manifolds,
domain decomposition, etc., applied to problems in solid and fluid
mechanics and other fields of science and engineering. These often
imply the formulation of a set of ordinary or partial differential
equations approximating the original systems of governing equations,
which are ultimately solved on serial, vector or parallel computers.

The aims of the symposium are to promote interdisciplinary communication
leading to a better understanding of the underlying links between these
methodologies, to review past and present achievements, to identify
areas for new research with potential impact on future applications,
and to collect this accumulated knowledge in a unique reference volume
(of peer reviewed papers) to be published soon after the symposium.
The lecturers of the symposium are several internationally distinguished
researchers who have accepted invitations to participate and present
their work.

Abstracts outlining original papers are requested from potential
authors who should contact the Scientific Secretariat at the earliest
time. The number of authors and participants is limited,
therefore an early registration is urged to secure a place.

Abstracts are due before 15 September 1991.

Registration close: 15 October 1991

Scientific Secretariat
L S Xanthis (Director)
Sir George Cayley Institute for Computational Mechanics
The Polytechnic of Central London
115 New Cavendish Street London W1M 8JS
Tel: 071-911 5000 Fax: 071-911 5089

Monday, 11 Nov 91
Registration: at 30 Panepistimiou Street, Athens;
Reception: at the courtyard of the Museum of the History of
Athens University in Plaka-Old Athens, beneath the Acropolis hill.
Tuesday-Wednesday-Thursday, 12-13-14 Nov 91
Athens Technical Sessions: Keynote, Invited and Contributed Lectures;
Visits: Poseidon's Temple at sunset and other sites
of archaeological interest.
Friday-Saturday, 15-16 Nov 91
Olympia Cultural Sessions: Transfer to Ancient Olympia
(legendary scene of first Olympic games)
via Delphi (an awesome setting for an oracle);
Lectures embracing the scientific and humanistic cultures
at the Olympic Academy;


From: John R. Gilbert <>
Date: Fri, 6 Sep 1991 09:43:04 PDT
Subject: IMA Sparse Matrix Workshop

Sparse Matrix Computation:
Graph Theory Issues and Algorithms
October 14-18, 1991
Minneapolis, Minnesota


Attempts to solve efficiently very large sparse systems
of equations have spawned a multitude of important and
interesting problems. Some of these problems are numerical,
some are combinatorial, some can be phrased in terms of
questions about graphs, and some are "core computer science"
questions, involving the design and implementation of good
(and sometimes provably optimal) data structures. The purpose
of this workshop is to bring together people who work in
sparse matrix computation with those who conduct research in
applied graph theory and graph algorithms.

The workshop will consist of 14 one-hour invited talks, as
well as less formal problem sessions, working papers, and
software demonstrations. The workshop is open to all
interested participants. There is no registration fee, but
attendees are advised to call the IMA to make arrangements
for lodging as soon as possible. (See "Lodging" below.)

The workshop is sponsored by the Institute for Mathematics
and its Applications at the Univeristy of Minnesota, as
part of its Special Year on Applied Linear Algebra.


Alan George (Waterloo;
John Gilbert (Xerox PARC;
Joseph Liu (York;

Invited Speakers:

Ajit Agrawal (Brown).
Provably good elimination orderings using nested dissection.
Cleve Ashcraft (Boeing).
The aggregate/element model for column-based parallel sparse Cholesky.
Eleanor Chu (Waterloo).
A robust ICCG algorithm for sparse symmetric positive definite systems.
Stan Eisenstat (Yale).
Structural representations of sparse Schur complements.
Steve Kratzer (Supercomputing Research Center).
Massively parallel sparse matrix computation.
Gary Miller (Carnegie-Mellon).
A geometric approach to graph separators with applications to
sparse matrix computation.
Esmond Ng (Oak Ridge).
On symbolic Cholesky factorization.
Barry Peyton (Oak Ridge).
On finding miminum-diameter clique trees.
Paul Plassman (Argonne).
An efficient parallel iterative solver for large sparse linear systems.
Alex Pothen (Penn State).
Predicting the structure of sparse orthogonal factors.
Don Rose (Duke).
Numerical analysis of circuit simulation: The culture of CAzM.
Rob Schreiber (RIACS).
Are sparse matrices poisonous to highly parallel machines?
Pravin Vaidya (Illinois).
Constructing provably good cheap preconditioners for certain symmetric
positive definite matrices.
Steve Vavasis (Cornell).
Nested dissection for sparse nullspace bases.

Schedule of talks (still slightly fluid):

Monday Tuesday Wednesday Thursday Friday
Oct 14 Oct 15 Oct 16 Oct 17 Oct 18

9:15-10:15 am Agrawal Peyton Miller Ng Kratzer
10:30-11:30 am Schreiber Ashcraft Plassman Vavasis Chu
1:30- 2:30 pm Eisenstat Vaidya Pothen Rose
3:00- 5:00 pm ...Demos, working papers, problem sessions...

The workshop will conclude at noon on Friday Oct 18.


Housing for IMA workshops is arranged at the Days Inn Hotel. Anyone interested
in attending the workshop should call the IMA office, 612-624-6066, to request
a reservation at the Days Inn. A special rate of $34.00 plus tax has been
arranged for IMA workshop participants. Please call ASAP to insure that hotel
space is available.


From: Bob Russell <>
Date: 8 Sep 91 0:12 -0700
Subject: Nigeria Meeting

NA-Net members:
The message below from Simeon Fatunla has just reached me.
If there is the possibility that you could come to the
meeting it discusses, or if you simply would like to have
more information about it, I will try to handle your in-
quiries as quickly as possible. Thanks, Bob Russell



JANUARY 27 - 31, 1992

Main Topics:

Ordinary Differential Equations
Partial Differential Equations
Parallel Methods
Interval Arithmetic
Computational Fluids
Non-linear Dynamical Systems and Chaos
Numerical Software
Seismic Analysis
Computational Meterology
Computer Algebra

Preliminary List of Guest Speakers

Jim Verner (Kingston, CANADA)
John Pryce (Swindon, ENGLAND)
Sean Mckee (Glasgow, SCOTLAND)
K Dekker (Amsterdam, HOLLAND)
M N Spijker (Leiden, THE NETHERLANDS)
Emilo Spedicato (Bergamo, ITALY)
Bob Russell (Burnaby, CANADA)
M Nakashim (Kagoshima, JAPAN)
R O'Malley, Jr (Seattle, USA)
M Rump (Hamburg, GERMANY
Victor Pereyra (Los Altos, USA)
Peter Van Der Houwen (Amsterdam, THE NETHERLANDS)
C O A Sowunmi (Ibadan, NIGERIA)
M A Ibiejugba (Ilorin, NIGERIA)
Philip Sharp (Kingston, CANADA)
Peter Onumanyi (Ilorin, NIGERIA)
S Ibiyemi (Ilorin, NIGERIA)
T Tsuboi (Kyoto, JAPAN)
R O Ayeni (Ogbomosho, NIGERIA)
Dan Kannan (Athens, USA)
K Aderogba (Lagos, NIGERIA)
Akin Ojo (Ibadan, NIGERIA)


International Steering Committee:
S O Fatunla (Benin-City, NIGERIA)
Bob Russell (Burnaby, CANADA)
John Pryce (Swindon, UK)

Supporting Institutions:

Federal Ministry of Education; Lagos, NIGERIA
Federal Ministry of Science and Technology, Lagos, (NIGERIA)
National Mathematics Centre, Abuja; NIGERIA
International Centre for Theoretical Physics, Trieste; ITALY
Mathematical Association of Nigeria


The conference language is English. The scientific program will
consist of invited and contributed talks. There will be morning
and afternoon lectures of 60 minutes for invited lectures and 20
minutes for contributed papers.

How to contribute

Potential contributors should submit a one-page abstract
(together with their registration form) to Fatunla, Russell, or
Pryce. The one-page abstract should include the title and (list of)
author(s) in a form suitable for direct inclusion in the book of
abstracts. Please indicate the speaker's name if there are
several authors. If possible; submit abstracts by e-mail to
Professor Bob Russell, Department of Mathematics and Statistics,
Simon Faser University, CANADA; e-mail: or Dr.
John Pryce, Computational and Applied Mathematics Group, Royal
Military College, Shrivenham, Swindon, England e-mail: or by TELEX to Simeon Fatunla at
Deadline for Submission of Abstracts is November 30, 1991.

Book of Abstracts and Proceedings

A collection of all abstracts will be available to attendees at the
conference. There will be a proceeding of the conference. Two
copies of papers typeset with TEX and LATEX and on a diskette
should be made available at Registration.


The conference will be held at the University of Benin Auditorium.
On January 26th, the conference office will open from 4.00 pm.
Lectures will begin at 10.00 on January 27, 1992.

Benin City, NIGERIA Professor Simeon Ola Fatunla
Telex: 41365 UNIBEN NG (Director of Conference)


End of NA Digest