NA Digest Sunday, February 17, 1991 Volume 91 : Issue 7

Today's Editor: Cleve Moler

Today's Topics:


From: Bob Ward <ward@rcwsun.EPM.ORNL.GOV>
Date: Thu, 14 Feb 91 23:08:46 EST
Subject: 1991 Householder Fellow Named

June M. Donato has been selected as the winner of the 1991 Householder
Fellowship in Scientific Computing at the Oak Ridge National Laboratory
(ORNL). Ms. Donato is currently finishing her doctorate degree in
Applied Mathematics at UCLA working with Prof. Tony Chan. Her research
interests are in the numerical solution of partial differential
equations via iterative techniques and parallel computing.

Ms. Donato will be collaborating with the researchers in ORNL's
Mathematical Sciences Section and with applied computational scientists
in various divisions at ORNL on scientific problems involving high
performance computing. Her primary interest will be on parallel
iterative algorithms for solving large sparse systems resulting from
the discretization of scalar and coupled systems of partial
differential equations in three dimensions. Her fellowship appointment
will begin this summer.

The Householder Fellowship Program is supported by the Applied
Mathematical Sciences Subprogram of the U.S. Department of Energy.


From: Klas Nordberg <>
Date: Wed, 13 Feb 91 18:17:07 +0100
Subject: Two Matrix Questions

Hello !

I have two questions for the na-net concerning matrices.

Question #1

I know that for an anti-symmetric matrix A, exp(A) is always an
orthogonal matrix with determinant = 1. I would like to know if this
statement is reversible, ie is it always possible to write an
orthogonal matrix Q with determinant = 1 as Q = exp(A), where A is an
anti-symmetric matrix.

Question #2

Let the matrices represent linear transformations in an N-dimensional
vector space, where N = 2K. Denote a basis of this vector space with
ai, bi, i=1,2,...,K. (i is used as an index here). Given this basis we
can define K anti-symmetric matrices as follows

Ai = ai bi' - bi ai' i=1,2,...,K

where ' means transpose. All vectors are column vectors.

Let S be an arbitrary symmetric matrix. Then Pi = Ai S - S Ai is a
symmetric matrix for all i=1,2,...,K.

My question is: are the matrices Pi always linear independent. If not,
under what conditions are they linear independent.

I am most interested in the case where S have just a few eigenvectors
with non-zero eigenvalues.

With best regards

Klas Nordberg
Department of Electrical Engineering
Linkoping University



From: Tom Coleman <>
Date: Thu, 14 Feb 91 11:29:36 -0500
Subject: Postdoc Position at Cornell

The Cornell Computational Optimization Project (CCOP) has available a
postdoctoral research position beginning Fall 91.
CCOP consists of about seven faculty,
in both Computer Science and Operations Research at Cornell, as
well as several researchers/postdocs. We are interested in
all areas of COMPUTATIONAL OPTIMIZATION, continuous and discrete.
If you are interested please send your vita (and list at least 3 references) to

Professor T. Coleman
Computer Science
Cornell University
Ithaca, NY 14850.

You can also apply electronically:


Date: Tue, 12 Feb 91 15:52:00 EDT
Subject: Board on Mathematical Sciences

Larry Cox has recently stepped down from the position of staff
director, Board on Mathematical Sciences. An advertisement in
the New York Times listed the following position to be filled:


The National Research Council is seeking a Staff Director
for its Board on Mathematical Sciences. Responsibilities
include directing a professional staff, conducting a diverse
set of studies in the mathematical sciences, and
implementing those studies in concert with university,
governmental, and industrial sectors.

Requires PhD or equivalent in directly relevant field, 7-10
years relevant professional experience, extensive working
familiarity with research in pure and applied mathematics
and statistics, experience with administration and/or study
project management, and excellent management and
communication skills.

Please send a resume, salary requirement, and the names of
three references to Mr. Norman Metzger, NRC/CPSMA, 2101
Constitution Ave. NW, Washington, DC 20418.


From: Susan Goode <>
Date: Wed, 13 Feb 91 12:31:45 CST
Subject: Call for Images


The National Center for Supercomputing Applications (NCSA) is again
collecting data for a compact disk (CD). Copies of this CD will be available
at various conferences in 1991 and through NCSA. The CD will contain public
domain NCSA Scientific Software for the Macintosh, IBM PC, Sun, SGI and
X Window servers. Among these software packages are NCSA Telnet, NCSA
Image, NCSA DataScope, NCSA PalEdit, NCSA GelReader, NCSA Layout, NCSA
Image IP, NCSA PC Show, NCSA ImageTool, NCSA CompositeTool, NCSA X Image,
NCSA X DataSlice, NCSA HDF, etc. In addition to these programs, NCSA will
include approximately 500-600 Mbytes of images and animation sequences
from researchers around the world.

Those of you who submitted images in April for the Apple Science CD Vol. 2 can
expect to see the CD sometime in mid-1991. Although Apple had delayed the
production of the CD to take advantage of various new advances in CD Rom
technology, they intend to have the CD completed for SIGGRAPH '91. This CD,
like NCSA's will be of ISO9660 format, readable by most CD-Rom players.

NCSA is seeking examples of images that you have used in your research.
The deadline is March 15, 1991. We hope to have this CD available in the
second quarter of 1991.


I. TYPE Raster images and/or numerical data to produce raster images.
Please include the numerical data whenever possible.
II. SIZE Any size. Less than (640 x 480) preferred.
III. BITS OF COLOR/GRAYSCALE- 8 bit or 24 bit. 8 bit preferred.
IV. CATEGORIES - Unlimited number of entries in any or all categories

A. Single- stand alone image.
B. Group - set of images that may be related but are not
intended to be animated.
C. Animation - set of images which are intended to be
played in sequence, for example by NCSA Image.

V. CREDIT - For EACH example in EACH category you submit, please
include textfile (MicroSoft Word or ASCII text) with
information outlined below. BE AS CONCISE AS POSSIBLE!

Title: give some SHORT name or title for the image(s)

Description: describe the science and the content of the
image(s). Please include the number of images,
size in pixels (x by y), and the # of bits
color or grayscale. Include the format and the
details of associated palettes.

Generation: list software/hardware used to generate and/or
display the image.

Author(s): list name, address, and E-mail address.
Phone number is optional.

Reference(s): (optional) list references to science involved

Copyright: include a completed, signed copy of the
attached copyright form. NCSA must receive this
form prior to accepting your submissions
for the CD.

If at all possible attach a research article or abstract describing in
detail the research being done or similar completed research. NCSA prefers
disk copies but will also accept hardcopies.

FORMAT - NCSA will try to handle any format, but the following are preferred:

A. NCSA Hierarchical Data Format (HDF) - for images,
palettes and numerical data.
B. Raw raster/raw palette format.
C. Numerical data in ASCII using NCSA DataScope format.

Please include the numerical data whenever possible.

A. Mail MAC disk(s)
B. Mail a UNIX tar formatted 1/4" cartridge or 1/2" reel tape.
PLEASE specify the tar command to create the tape and on
what machine and Operating System.
C. Use anonymous FTP and put them in directory pub or incoming.
NCSA server has IP # You MUST E-mail Susan Goode
(address listed below) when you have done so. NCSA disk space is
D. Send small files in either binhex/SuffIt format or
UNIX compressed/uuencode format via E-mail to Susan
Goode (address listed below).

VIII. CONTACT - All submissions and questions to:

Susan Goode - NCSA Science '91 CD Project
NCSA Software Tools Group
152 Computing Applications Building
605 East Springfield Avenue
Champaign, Illinois 61820
E-MAIL: (Internet)
or sgoode@ncsavms (bitnet)

Thank you,

Susan Goode
CD Project Coordinator


From: Len Colgan <>
Date: Tue, 12 Feb 91 11:25 +1030
Subject: CTAC91, Computational Techniques and Applications

Computational Techniques and Applications Conference

15-17 July, 1991
Adelaide, South Australia

Second Announcement and Final Call for Papers

This biennial conference provides an interactive forum for scientists,
engineers and mathematicians interested in the use and development of
more efficient computational techniques and their application to engineering,
scientific and other problems.
The conference programme will include invited lectures, contributed papers
and poster sessions. The topics of the invited and review lectures are
structured to achieve a balance between computational techniques and
applications and will be presented by distinguished overseas and Australian
research workers. The contributed papers will focus on specific research
topics and will be of a somewhat shorter duration.
The Conference Proceedings will be published in hardback form. Preprints of
all papers will be available to delegates at the conference. All sessions
will be held at The University of Adelaide situated within 5 minutes walk
of the city centre.

Organising Committee
Assoc. Prof. B.J. Noye (Chairman)
University of Adelaide
G.P.O. Box 498
Adelaide, 5001
South Australia
Phone: (08) 228 5075 Fax: (08) 224 0227

B.R. Benjamin (Director)
University of South Australia
The Levels, 5095
South Australia
Phone: (08) 343 3084 Fax: (08) 349 4367

L.H. Colgan (Treasurer)
University of South Australia
The Levels, 5095
South Australia
Phone: (08) 343 3038 Fax: (08) 349 4367
Email: or

Dr. S. Elhay
University of Adelaide

Dr. W. Henderson
University of Adelaide

Dr. J. Kautsky
Flinders University of South Australia

L.M. Sheppard
DSTO Ordnance Systems Division

Call For Papers
Authors are invited to submit original papers on specific research topics
following the guidelines outlined in the preamble. An abstract of not more
than 500 words must be submitted by 27 February 1991. Three copies of each
abstract are required and should be sent to Assoc. Prof. B.J. Noye at the
address given below. Authors of papers accepted for presentation are required
to provide sufficient preprints for all registrants.
Assoc.Prof. B.J. Noye
Department of Applied Mathematics
University of Adelaide
G.P.O. Box 498
Adelaide, 5001
South Australia
Phone: (08) 228 5075
Fax : (08) 224 0227

Registration will take place on the afternoon and evening of 14 July, 1991.
The registralian fee will cover the reception, morning and afternoon teas
and conference dinner. Those who would like to purchase a copy of the published
conference proceedings at discounted price should indicate on the registration
form. The Registration fee is:
$A190 for AMS members
$A125 Students
A discount of $A25 will apply to all registrations paid before 1 June 1991.

Student Prize
A prize of $A250 will be awarded to the student who is judged to have presented
the best contributed paper.

A two day Workshop will be arranged on 18,19 July, involving practical access
to a CRAY supercomputer. Further details, including costs, are available on

Further information concerning the conference and workshops can be obtained
Len Colgan
School of Mathematics & Computer Studies
University of South Australia
The Levels
South Australia, 5095
Phone: (08) 343 3038 Fax: (08) 349 4367
Email: or


From: Mac Hyman <>
Date: 14 Feb 91 00:08:40 GMT
Subject: Conference on Computational Issues in Nonlinear Science

The 11th Annual International Center for Nonlinear Studies Conference on
Experimental Mathematics: Computational Issues in Nonlinear Science

Will be held at the J. R. Oppenheimer Study Center, Los Alamos, New Mexico
May 20-24, 1991

This conference will focus on computational issues, numerical methods
and mathematical models for reliable, efficient computer simulations of
nonlinear phenomena. There will be survey talks on current research
and applications of numerical methods for solving ordinary and partial
differential equations, including adaptive grid generation, symplectic
difference approximations, methods for multiple time and space scales,
and methods for solving large nonlinear systems. Special talks will
highlight some of the recent advances in simulations and analysis of
chaotic dynamics. There will be talks on the models and capabilities of
the major computer codes for global climate change, turbulence modeling
and large scale simulations of complex fluid flows. Also, speakers will
describe the revolution in scientific computing environments and
visualization techniques.

Speakers and topics include:

Chris Anderson (UCLA) Vortex methods for computational fluid dyanmics
Tom Banks (USC) Parameter estimation
Tony Chan (UCLA) Domain decomposition methods for PDEs
Shi-Yi Chen (LANL) Lattice gas methods for complicated flows
Phil Colella (UCB) Computational fluid dynamics
Ken Eggert (LANL/EES) Lattice gas methods for complicated flows
Bjorn Engquist (UCLA) Numerical methods and homogenization
Joe Flaherty (RPI) Adaptive mesh methods for PDEs
Peter Ford (LANL) Man/Machine interfaces, distributed computer systems
Bill Gear (NEC) Methods with Special Properties
Gary Glatzmaier (LANL) Modeling the global 3D dynamics of the Earth's
atmosphere and interior
Celso Grebogi (U Md) Simulations and analysis of chaotic dynamics
Leslie Greengard (NYU) Fast algorithms for particle simulations
Chuck Hansen (LANL) Visualization of scientific data
Bill Henshaw (IBM) Spectral and vortex methods for calculating fluid flows
Ahied Iserles (Cambridge) Analysis of numerical methods for ODEs
Heinz-Otto Kreiss (UCLA) Multiple time and space scales in PDEs
Peter Lax (NYU) Deterministic analogues of turbulence
Tom Manteuffel (UC Denver) Adaptive acceleration methods for algebraic systems
Bill Newman (UCLA) Scaling laws for failure in self-similar systems
Stan Osher (UCLA) Image enhancement using nonlinear PDEs
Linda Petzold (LLNL) Numerical methods for differential algebraic systems
Jeff Saltzman (LANL) Adaptive mesh methods for PDEs
J. M. Sanz-Serna (U. Valadolid) Numerical methods for differential equations
Gil Strang (MIT) Wavelets and numerical methods
Edriss Titi (Cornell/UC Irvine) Approximations of inertial manifolds
Greter Tryggvason (U. Mich) Dynamics and modeling of interfaces
Burt Wendroff (LANL) Numerical methods for PDEs
Art Winfree (UAz) Pattern formation in biological systems

The refereed proceedings will be published in a special hardbound
special issue of the Physica D Journal. There will be two poster
sessions for the participants to present their research and
computational models. The participants presenting posters may also
submit a paper for publication in the proceedings. If you wish to present
a poster, please send a title and abstract to the address below before
May 1. There will be a few grants (averaging $200 each) to help cover
the expenses of participants presenting posters. These grants are
primarily for students and other young researchers without other
sources of financial support to attend the meeting. If you wish to be
considered for this partial support, please indicate it when you submit
your poster abstract.

Non-US Citizens must supply visa information to the Center for
Nonlinear Studies before March 4th and receive approval from the
Department of Energy before attending the conference. We ask that
these participants reply as soon as possible to receive the necessary forms.

For more information contact Mac Hyman, (505) 667-6294,
or Barbara Rhodes (505) 667-1444,, FAX (505) 665-2659

The 11th Annual International Conference is sponsored by the
U.S. Department of Energy, Applied Mathematical Sciences Program
and the Center for Nonlinear Studies, Los Alamos National Laboratory.


End of NA Digest