NA Digest Sunday, November 20, 1994 Volume 94 : Issue 47

Today's Editor:
Cleve Moler
The MathWorks, Inc.

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From: Jens Lorenz <>
Date: Mon, 14 Nov 94 13:33:29 +0100
Subject: Magic Hexagon

The following magical hexagon out of the first
19 integers has sum 38 in each horizontal
and diagonal.

10 12 16

13 4 2 19

15 8 5 7 3

14 6 1 17

9 11 18

I have this from my Highschool teacher, who says it
is due to a railroad engineer of the Old Wild West.

I wonder if someone has seen this before, knows about
its origin, or generalizations (except magic squares).
Please let me know.

Jens Lorenz
Numerische Mathematik
RWTH Aachen
Templergraben 55


From: Cees deValk <>
Date: Wed, 16 Nov 94 15:47:10 +0100
Subject: Least Squares Problems with Identical Hessians

Dear reader, my problem is to approximate the minimizers of m least-squares
problems of the form

Find vectors x(1),..., x(m) in R^k, each minimizing

|| y - F x(i) ||^2 + c(i)^T x(i) i= 1,..., m

with given vector (of observables) y and large sparse matrix (numerical
model) F, and given vectors c(1),..., c(m). The dimension k is large. The
number m of least-squares problems is much smaller, but still I wouldn't
like to carry out m minimizations since the m problems have a common Hessian.
Do you know if a method or strategy exists to exploit this common structure?

It may be relevant that I do not intend to find very accurate
approximations to the m minimizers (that would be too expensive), but the
accuracies should be of the same order of magnitude. Therefore, I was
thinking of somehow minimizing the m functionals simultaneously rather
than sequentially.

Cees de Valk
The Netherlands


From: Roland Sweet <>
Date: Mon, 14 Nov 1994 12:48:47 -0700
Subject: New Mosaic site at University of Colorado at Denver

Dear Colleagues,

The Mathematics Department at the University of Colorado at Denver
has recently created a Mosaic site. Information is available there
about our graduate programs in applied mathematics (M.S. and Ph.D.).
We will be adding more information later. Please feel welcome to take
advantage of this information and to recommend it to interested students.
To make a connection to our site use URL


From: Anke Haenler <>
Date: Tue, 15 Nov 94 10:52:01 +0100
Subject: Contact in Great Britain Wanted

Dear Colleagues,

I would appreciate any suggestions for further cooperation:

My name is Anke Haenler and I have been working in Fraunhofer
Institute of Computer Graphics in Rostock for one and a half year.
I'm involved in a group, that deals with visualisation in the field
of marine biology.

We have got experiences in the following fields:
* programming in UNIX, C, X11, Motiv and Macro Languages (PV-WAVE),
* visualisation of marine and cartographic data,
* Geographical Information Systems related to the exploration of the sea,
* writing studies about application of Geographic Information systems.
* Computer Graphics,

Furthermore we have knowledge in the field of
* databases and
* how to solve nonlinear systems of differencial equations.

We have a www-server in our institute, there you can receive
more detailled information about our institute. The address is

We are looking for contact with nonprofite research institutes in Britain
with the aim of a mutual project.
It would be fine (but no assumption), if we could find a partner, who works
in a theoretical field, e.g.
* theoretical ecology,
* modelling and simulation of marine ecosystems,
* theoretical epidemiology,
* modelling and simulation of growth and/or diffusion events of
interacting particles,
* reaction diffusion mechanism.

In addition it would be of interest, if we could find a partner in this context,
who has got a lot of data to analyse.

I am grateful for any suggestions.

Anke Haenler
FhG/IGD 0381.4024.120(Telefon)
18059 Rostock


From: Bette Byrne <>
Date: Wed, 16 Nov 1994 09:59:49
Subject: Bill Morton CFD Prize


In order to mark the contributions of Professor Bill Morton in the field of
computational fluid dynamics it has been decided to offer a prize, to be
known as ``The Bill Morton CFD Prize'' for a paper on CFD by a young research
worker, at the forthcoming Conference on Numerical Methods for Fluid Dynamics
to be held at Oxford in April 1995. The Prize paper, which should be suitable
for a 30 minute talk and which will be presented by the author at a special
session of the Conference, will be chosen from two sources, (a) eligible
contributed papers submitted for the Conference by the deadline of 9th December,
1994, and (b) a special submission of papers for the Prize alone, for which the
deadline is extended to 16th January, 1995. The winner will be notified by
31st January, 1995.

The intention is to encourage a young research worker in CFD and for this
reason the authors should be under the age of 31 on 6th April, 1995. Each
candidate should include a statement of his/her age on 6th April, 1995 and
should indicate that he/she would be available to present his/her paper at
the Conference.

Papers for the Conference and/or the Prize should be submitted to:

Mrs B Byrne
Oxford University Computing Laboratory
Wolfson Building, Parks Road
Oxford OX1 3QD

Tel: 0865 273883
Fax: 0865 273839


From: Gil Strang <>
Date: Fri, 18 Nov 94 17:54:28 EST
Subject: Workshop on Wavelets and Filter Banks

Workshop on Wavelets and Filter Banks
January 13-16
San Jose State University
San Jose, California

The goal of the Workshop is to present the basic ideas in design and
application of filters and wavelets, and also to keep up with the rapid
development of these subjects. It will be a very active four days!
We study in particular the approximation and compression of
signals and images.

The Workshop is organized by Gilbert Strang and Truong Nguyen, and
the notes are a preliminary form of a book to appear in summer 1995.
For a complete announcement of the Workshop please send an email note
to .


From: Francois E. Cellier <>
Date: Sun, 13 Nov 1994 7:45:18 -0700 (MST)
Subject: Conference on Bond Graph Modeling and Simulation


Part of the 1995 Western Multiconference on Computer Simulation
Sponsored by the SCS
January 16-18, 1995
Tropicana, Las Vegas, Nevada, USA

Softcopies of the Final Program of this event can be requested from:

Francois E. Cellier
Dept. of Electr. and Computer Engr.
University of Arizona
Tucson, Ariz. 85721

Phone: (602) 621-6192
FAX: (602) 621-8076
EMail: Cellier@ECE.Arizona.Edu


From: Panos Pardalos <>
Date: Mon, 14 Nov 1994 16:04:53 -0500
Subject: Conference on Global Optimization



APRIL 28-30, 1995

The Second International Conference on Global Optimization will take
place April 28-30, 1995 at Princeton University.

Conference Goals:
Bring together the most active researchers in global optimization.
Exchange ideas across discipline boundaries of applied mathematics,
computer science, engineering, computational chemistry and biology.
Present new computational methods and applications of global optimization.

Main Conference Themes:
New advances in deterministic and stochastic methods for global
optimization. Distributed computing methods in global optimization.
Applications of global optimization in engineering, computer science,
environmental studies, computational chemistry and biology.

Deadline for Contributions:
January 10, 1995: Submission of manuscripts (4 copies) to one of the
organizers.Early submissions are encouraged. Decisions on selection
will be promptly communicated to the authors by e-mail or FAX.

Submitted manuscripts will be regularly refereed and all accepted
manuscripts will be published in one volume by "Kluwer Academic Publishers"
in the new book series "Nonconvex Optimization and Its Applications".
A collection of manuscripts will be published in a special issue of the
"Journal of Global Optimization". The manuscripts should use the style
files which are available through the Internet by ftp as follows:

ftp <enter>
name: anonymous <enter>
password: (your e-mail address) <enter>
cd Kluwer/styles/books (or journals) <enter>

Conference Format:
All presentations are invited and each talk will be of 25 minute duration.

Pre-registration is required (by March 15, 1995) to attend the conference.
A registration fee of $250 per participant will cover conference expenses.

The conference is organized in cooperation with the SIAM Activity Group
on Optimization.

Additional information can be obtained from the conference organizers:

Professor C.A. Floudas
Department of Chemical Engineering
Princeton University
Princeton, NJ 08544-5263
Tel.: (609) 258-4595
Fax : (609) 258-0211

Professor P.M. Pardalos
Center for Aplied Optimization and
Department of Industrial and Systems Engineering
University of Florida
Gainesville, FL 32611
Tel : (904) 392-9011
Fax : (904) 392-3537
e-mail :


From: Center for Applied Optimization <>
Date: Tue, 15 Nov 1994 14:29:52 -0500
Subject: Conference on Network Optimization Problems

FEBRUARY 12-14, 1996


Bill Hager Don Hearn Panos Pardalos

The conference will bring together researchers working on many
different aspects of network optimization: algorithms, applications,
and software. The conference topics include diverse applications
in fields such as engineering, computer science, operations research,
transportation, telecommunications, manufacturing, and airline scheduling.
Since researchers in network optimization come from many different areas,
the conference will provide a unique opportunity for cross-disciplinary
exchange of recent research advances as well as a foundation for joint
research cooperation and a stimulation for future research.

Advances in data structures, computer technology, and development of new
algorithms have made it possible to solve classes of network optimization
problems that were recently intractable. For example, recent advances have
been made in techniques for solving problems related to airline scheduling,
satellite communication and transportation, and VLSI chip design.
Computational algorithms for the solution of network optimization problems
are of great practical significance.

The conference will be held at the Center of Applied Optimization,
University of Florida, Gainesville, Florida.
All presentations are invited. A collection of refereed papers will be
published in book form by Kluwer
Academic Publishers. Details will be available at a later time.

For further details, please contact one of the conference organizers.


From: Jean Marie Chesneaux <>
Date: Wed, 16 Nov 94 10:40:20 GMT
Subject: Conference on Real Numbers and Computers


- Location and date:

Ecole des Mines de Saint-Etienne,
Saint-Etienne, FRANCE
April 4-5-6 4-5-6 Avril 1995

sponsored by:

- Ecole des Mines de Saint-Etienne
- Centre National de la Recherche Scientifique
- Ministere de l'Enseignement Superieur et de la Recherche
- Laboratoire de l'Informatique du Parallelisme, Ecole Normale Superieure de

Deadline for submission of manuscripts

December 20 1994

You can send 4 copies of a printed version of a full paper (not an abstract) to:

Jean-Michel Muller
Laboratoire LIP,
Ecole Normale Superieure de Lyon,
46 Allee d'Italie,
69364 LYON Cedex 07, FRANCE
(Phone +33 72 72 82 29 Fax +33 72 72 80 80)

Or a PostScript or LaTeX version of your full paper to:
(subject: RealNumbers)

Electronic submissions are encouraged, but please make sure that your PostScript files can be printed.

Languages: English/Francais

As a courtesy to non-French speaking attendees, we ask French speaking
people to have at least either their talk or their transparencies in English.

The proceedings will be distributed on the conference site

Topics (including, not restricted to)

- Algorithms and architectures for <<serial>> and <<on line>> arithmetics.
- Relations between numbers theory, automata theory and computer arithmetic.
- Number systems
- Floating point arithmetic
- Calculability
- Symbolic manipulation of numbers
- Algorithms for <<exact>> computing
- Multi-precision, interval arithmetic
- Accuracy problems in various different fields
(geometry, physics,...), and proposed solutions.

Efficient handling of real numbers in a computer is not yet solved in a
satisfying way. The "floating point" formats most often used in scientific
computing usually give sufficient results, but some reliability problems
can occur. Program portability problems could imply some rewriting
costs: some programs which work well with a machine, could become
unreliable with another one. Users (from computer algebra, algorithmic
geometry, ...) may need results far more accurate (even "exact") than the
ones obtained with usual number systems. Many members of the scientific
community are concerned by this problem, they could share their knowledge
and come up with new solutions. But they do not have the opportunity to meet,
they do not belong to the same scientific fields (computer science, number
theory, numerical analysis, computer algebra...) and they have a different
vocabulary. The aim is to put them together during this meeting (the
"rule of the game" should be that everybody should speak a common language),
in order to establish some collaborations.

-- Local committee

- Jean-Claude Bajard, Laboratoire LIM, Universit'e de Provence
- Hamid Bessalah, (Centre de d'eveloppement des technologies avanc'ees,
Alger, Algerie)
- Marc Daumas, Laboratoire LIP, ENS Lyon
- Xavier Merrheim, Laboratoire LIP, ENS Lyon
- Dominique Michelucci,Ecole des Mines de Saint-Etienne
- Anne Mignotte, Laboratoire LIP, ENS Lyon
- Jean-Michel Moreau, Ecole des Mines de Saint-Etienne
- Jean-Michel Muller, CNRS, Laboratoire LIP, ENS de Lyon

Program committee

- J.P. Allouche (LMD, Universit'e de Marseille)
- J.C. Bajard (LIM, Universit'e de Provence)
- J.C. Berg`es (CNES, Toulouse)
- H. Bessalah (Centre de d'eveloppement des technologies avanc'ees, Alger)
- J.M. Chesneaux (Laboratoire Masi, Paris)
- C. Frougny (Laboratoire LITP, Paris)
- M. Margenstern (Univ. Paris XI)
- D. Michelucci (Ecole des Mines de Saint-Etienne)
- J.M. Moreau (Ecole des Mines de Saint-Etienne)
- J.M. Muller (CNRS, Laboratoire LIP, Lyon)
- J.P. R'eveilles (Universit'e de Strasbourg)
- J.L. Roch (Laboratoire LMC, Grenoble)
- J. Vuillemin (INRIA)

If you plan to attend the meeting, please immediately send an e-mail or a
letter to Jean-Michel Muller (at the address given above), this will help
to have an estimation of the number of attendees.


A special issue of "Theoretical Computer Science" dealing with the same
topic (Real Numbers and computers) will appear after the conference.
Although separate submissions to the conference or the special issue are
possible, we encourage people to submit a paper to the conference and
then, after having their communication accepted, to submit an improved
version to the special issue.

To get informations on that special issue, please send a letter or an
e-mail to Jean-Michel Muller, at the address given above.


From: Christopher T H Baker <>
Date: Wed, 16 Nov 94 13:18:03 GMT
Subject: Research Fellowships at Manchester University


Research Fellowships/Lectureships within the University were recently
advertised in Nature, the Times Higher Education Supplement, and The
Guardian newspaper. Applications are expected from across the whole
spectrum of pure and applied mathematics (these gained grades 4 & 5
respectively -- out of 5 -- at the last Research Assessment Exercise)
and in particular in the area of computational mathematics. The
emphasis is on proven research potential.

Subject to performance, tenure-track appointments are expected to be
available at the end of a 5 year appointment. Senior appointments are not

Mathematics applicants should write to the Director of Personnel,
Academic Appointments, The University, Manchester M13 9PL England
FAX: +44 (0)161 273 5306 for further details, quoting reference 397/94,
and the actual application itself (also to be sent to the Director of
Personnel) should consist of a statement of interests, CV, and
the names of 3 referees and quote the reference number 397/94 .
The CLOSING date is December 19th 1994.

Please do not E-mail Prof. Baker (who is on research leave!); the
Director of Personnel will be able to send details of the department
and additional queries can be answered by the Head of Department.


From: Ian Gladwell <>
Date: Mon, 14 Nov 1994 16:21:30 -0600
Subject: Positions at Southern Methodist University

Southern Methodist University
Department of Mathematics
Assistant Professorships

The Department of Mathematics at Southern Methodist University invites
applications for two tenure-track assistant professorships with employment
beginning the Fall semester of 1995. All applicants must provide evidence
of outstanding achievement or potential for research in applied
mathematics, numerical analysis or scientific computation, and a strong
commitment to undergraduate and graduate teaching. The standard teaching
load is two courses (six hours) per semester.

The Department of Mathematics has an active doctoral program in applied
mathematics, numerical analysis and scientific computation; research
interests include asymptotic and perturbation methods, bifurcation theory,
dynamical systems, fluid mechanics, mathematical biology, mathematical
software, nonlinear waves, and the numerical analysis of differential
equations. Fourteen of the seventeen faculty are applied or numerical
mathematicians. Senior faculty include W.E. Ferguson (numerical partial
differential equations), I. Gladwell (mathematical software), R. Haberman
(perturbation theory), M. Melander (computational fluid dynamics), and
L.F. Shampine (numerical ordinary differential equations). The Department
of Mathematics at Southern Methodist University has access to distributed
workstations, good Internet connections and a 20 processor Sequent

Applications will be accepted until February 1, 1995, or until the
positions are filled. Send a letter of application and a vita to:
Professor George Reddien, Chairman, Department of Mathematics, Southern
Methodist University, Dallas, Texas 75275-0156. (Tel: (214) 768-2506;
Fax: (214) 768-4138). Applicants should arrange for three letters of
reference to be sent directly to Professor Reddien. His email address

SMU is an equal opportunity/affirmative action/Title IX employer.


From: Elbridge Puckett <>
Date: Tue, 15 Nov 94 01:26:37 PST
Subject: Positons at U. C. Davis


Applications are invited for three anticipated tenure track positions
and several Visiting Research Assistant Professorship (VRAP) positions in
the Department of Mathematics, University of California, Davis, effective
July 1, 1995. These positions are contingent on budgetary approval.

Appointments of the tenure track positions will be made at the Assistant
Professor level commensurate with qualifications. Qualifications include
a Ph.D. degree in mathematical sciences and great promise in research and
teaching. Duties include mathematical research, undergraduate and
graduate teaching, and service. For the tenure track positions, the
Department of Mathematics is recruiting in

1) Computational Mathematics,
2) Analysis/PDEs, and
3) Algebra/Number Theory.

The VRAP positions are renewable for a total of three years with
satisfactory performance in research and teaching. The VRAP applicants
are required to have completed their Ph.D. no earlier than 1991. The
Department of Mathematics is interested in applicants in the following
areas for the VRAP positions:

1) Computational Mathematics,
2) Analysis/PDEs,
3) Algebra/Number Theory,
4) Applied Mathematics,
5) Mathematical Physics, and
6) Geometry/Topology.

The tenure-track positions are open until filled, but to assure
consideration, applications should be received by December 16, 1994.
The application deadline for the VRAP positions is February 1, 1995.

To initiate the application process, request an application package
by writing an e-mail message to:

Those who do not have access to e-mail can obtain the package by
writing to:

Chair of Search Committee
Department of Mathematics
University of California
Davis, California 95616-8633

The Department of Mathematics at UC Davis is an affirmative action
employer with a strong institutional commitment to the achievement of
diversity among its faculty and staff. In this spirit, we are
particularly interested in receiving applications from women, persons
of color and persons from other underrepresented groups.


From: Alessandro Russo <>
Date: Thu, 17 Nov 1994 13:57:27 +0100
Subject: Positions at the Istituto di Analisi Numerica del CNR, Pavia, Italy

There are 2 positions available at the Istituto di Analisi
Numerica del CNR, Pavia, Italy, as Researcher at the initial level
in the field of Numerical Analysis of PDEs.

Only citizens of the European Community Countries can apply and
a good knowledge of the Italian language is required. (Candidates must
succeed in a written and in an oral examination in Italian).

The research program of the Istituto di Analisi Numerica del CNR of Pavia
includes Finite Element Methods for PDEs, Wavelets, Biomathematics,
Artificial Intelligence and other topics.

The deadline for applications is December 9th, 1994.

For further information please contact

Alessandro Russo
Istituto di Analisi Numerica del CNR
via Abbiategrasso 209
I-27100 Pavia (ITALY)

tel: +39 - 382 - 529 600
fax: +39 - 382 - 529 566



From: SIAM <>
Date: Mon, 14 Nov 94 10:47:35 EST
Subject: Contents, SIAM Matrix Analysis

Table of Contents
SIAM Journal on Matrix Analysis and Applications
April 1995
Volume 16, Number 2


Matrix Powers in Finite Precision Arithmetic
Nicholas J. Higham and Philip A. Knight

The Extended Linear Complementarity Problem
O. L. Mangasarian and J. S. Pang

Maximum Entrophy Elements in the Intersection of an Affine Space
and the Cone of Positive Definite Matrices
Mihaly Bakonyi and Hugo J. Woerdeman

A Finite Procedure for the Tridiagonalization of a General Matrix
A. George, K. Ikramov, A. N. Krivoshapova, and W.-P. Tang

A Look-Ahead Block Schur Algorithm for Toeplitz-like Matrices
Ali H. Sayed and Thomas Kailath

Computing Exact Componentwise Bounds on Solutions of Linear Systems
with Interval Data is NP-Hard
Jiri Rohn and Vladik Kreinovich

Hamilton and Jacobi Meet Again: Quaternions and the Eigenvalue Problem
Niloufer Mackey

On the Index of Block Upper Triangular Matrices
Rafael Bru, Joan Josep Climent, and Michael Neumann

Some Remarks Concerning Iterative Methods for Linear Systems
Fred B. Weissler

A Practical Upper Bound for Departure from Normality
Steven L. Lee

Forward Stability and Transmission of Shifts in the QR Algorithm
David S. Watkins

Linear Operations on Matrices: Preserving Spectrum and Displacement Structure
Kenneth R. Driessel and Wasin So

Rank M Wavelets with N Vanishing Moments
Peter Niels Heller

Analysis of a QR Algorithm for Computing Singular Values
S. Chandrasekaran and I. C. F. Ipsen

Displacement Structures of Covariance Matrices, Lossless Systems,
and Numerical Algorithm Design
Phillip A. Regalia and Francois Desbouvries

Condition Estimation for Matrix Functions via the Schur Decomposition
Roy Mathias

The p-Product and Its Applications in Signal Processing
Huixia Zhu and Gerhard X. Ritter

Oblique Projection Methods for Large Scale Model Reduction
Imad M. Jaimoukha and Ebrahim M. Kasenally

Fast Transform Based Preconditioners for Toeplitz Equations
E. Boman and I. Koltracht

The Euclidian Distance Matrix Completion Problem
Mihaly Bakonyi and Charles R. Johnson

Fast Algorithms for Confluent Vandermonde Linear Systems and
Generalized Trummer's Problem
Hao Lu

Backward Error Analysis for the Constrained and Weighted Linear
Least Squares Problem When Using the Weighted QR Factorization
Marten Gulliksson

Approximations to Solutions to Systems of Linear Inequalities
Osman Guler, Alan J. Hoffman, and Uriel G. Rothblum


End of NA Digest