NA Digest Saturday, August 16, 2003 Volume 03 : Issue 33

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

Submissions for NA Digest:

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Information via e-mail about NA-NET: Mail to


From: Arnold Neumaier <>
Date: Mon, 11 Aug 2003 10:41:46 +0200
Subject: Re: Permanents in O(n^3)

On 08 Aug 2003, I asked in NA-net:

Is there an algorithm for calculating the permanent
of an n x n matrix in O(n^3) operations?

The answer is probably: No.
Computing the permanent of a (0,1)-matrix in exact arithmetic is equivalent
to counting the number of perfect matchings in an associated graph, which
is a #NP-complete problem. Thus (unless P=NP), it is unlikely that a
polynomial algorithm exists.

A more informative summary of the answers I got (from Brian Borchers,
David Bindel, Vladik Kreinovich, Jonathan Lee, and Gaston Gonnet) is
posted on
[~ is a tilde].

Arnold Neumaier


From: Siegfried Rump <>
Date: Fri, 15 Aug 2003 00:37:11 +0200 (CEST)
Subject: A Historical Question II

In May this year I asked for originals of an envelope from Yorktown Heights
with an imprint "2^19937-1 is a prime" and an envelope from Urbana with a
postmark "Four colors suffice".

Fortunately I received both, from Urbana just this week from Bhama Srinivasan.
I want to use photos of the envelopes (and and express my thanks) in an article
about computer-assisted proofs, but unfortunately I lost the name and address
of the friendly colleague who sent me an original envelope from Yorktown.
Could you please send me a mail (and please accept my apologies for

Best wishes

Siegfried M. Rump
Inst. f. Computer Science III
Technical University Hamburg-Harburg
Schwarzenbergstr. 95
21071 Hamburg


From: Mimi Celis <>
Date: Mon, 11 Aug 2003 09:49:41 -0700
Subject: Positive Part of a Matrix

We have an application that has a 6x6 symmetric matrix, with positive
and negative eigenvalues. The app needs to get just the positive part
of this matrix, i.e, formally compute the eigenvalues and vectors,
zero the negative eigenvalues and reconstruct the matrix. Since there
are billions of these to do, we are looking for a very efficient way of
doing this. Are such efficient algorithms available?

-- Mimi


From: Rob Knapp <>
Date: Tue, 12 Aug 2003 11:24:33 -0400
Subject: Mathematica 5

Newly Released Mathematica 5 Outperforms Dedicated Numerical Systems

Wolfram Research has recently released Mathematica 5--the new
high-performance version of its award-winning technical computing software.
Key new technologies enable Mathematica 5 to outperform dedicated numerical
systems in raw computational speed, while introducing a host of innovative

"In some cases, Mathematica 5 is 1000 times faster than previous versions
and surpasses the speed of dedicated numerical systems too," says Tom
Wickham-Jones, Director of Strategic Kernel Development for Wolfram
Research. "Yet to achieve this, we've compromised none of the accuracy or
expert nature of Mathematica. To the contrary, we've enhanced them while at
the same time adding even more capabilities."

Mathematica 5 introduces extensive new functionality, much of which is based
on algorithms that are exclusive to Mathematica 5. Other algorithms provide
functionality that was up to now only available in custom packages costing
tens of thousands of dollars. "The most impressive achievement is the
quantity of original research that went into this version--over 100 new
algorithms for symbolic and numeric computation have been implemented by
in-house developers," says Roger Germundsson, Director of R&D for Wolfram

A key objective in developing Mathematica 5 was to integrate algorithmic
advances and data structures into the language in a natural way. For
example, "When we starting using sparse matrices for improving scalability
in solving partial differential equations and large scale optimization
problems we made the considerable extra effort needed to incorporate them
fully into Mathematica," says Robert Knapp, manager of the numerical
computation development group. "With the full integration of the sparse
array technology in Mathematica 5, we have extended the flexibility and
usefulness of sparse data structures."

Other features of interest to this group include:

* Record-breaking speed for numerical linear algebra using enhanced LAPACK
with optimized BLAS
* Wide-ranging support for fast sparse matrix operations
* New-generation optimized numerical solvers for ordinary and partial
differential equations
* Major new algorithms for solving equations and inequalities symbolically
over complex numbers, reals, and integers
* High-performance optimization and linear programming including interior
point method
* Extensive support for vector and array functions in numeric solvers
* State-of-the-art solver for recurrence equations
* Fully integrated solver for differential algebraic equations
* Support for 1 + n-dimensional evolution partial differential equations
including arbitrary order finite difference and pseudospectral methods.
* Broader support for domain specifications in symbolic computation
* Optimized versions available for 64-bit hardware and operating systems

In Mathematica 5, technologies such as packed arrays, sparse arrays,
automatic algorithm selection, and symbolic preprocessing have helped to
deliver a unique combination of speed, flexibility, and functionality.

Mathematica 5 is available for Windows, Mac OS X, Linux (x86, Alpha),
Solaris, HP Tru64 Unix, HP-UX, IBM AIX, and compatible systems. More product
details are available at:


From: Roderick Melnik <>
Date: Mon, 11 Aug 2003 13:31:05 +0200
Subject: Workshop in Denmark on Mathematics for Industry

Final Announcement:

The 47th European Study Group with Industry and
The Mathematics for Industry Workshop,
Denmark, August 24--29, 2003

This is the final call and invitation to participate in a premier
problem-solving engineering mathematics conference and its embedded
Mathematics for Industry Workshop.

The 47th ESGI and its embedded Mathematics for Industry Workshop will
take place in Denmark and will be hosted by the University of Southern
Denmark in the picturesque Soenderborg/Graasten area. Five projects will
be presented by some of the leading industrial companies and the event
will feature the Mathematics for Industry workshop with lectures given by

Professor H. Thomas Banks (North Carolina State University),
Professor Martin Brokate (Technical University of Munich),
Professor Mark Cross (University of Greenwich).

The program of the meeting is on-line at the conference site:

We look forward to welcoming you at the meeting
(ESGI47 Secretariat: e-mail: Tel.: +45 6550 1690)


From: Dugald Duncan <>
Date: Wed, 13 Aug 2003 17:58:50 +0100 (BST)
Subject: Scottish Computational Mathematics Symposium

Computational Modelling in Medicine
Wednesday 17 September 2003
Kings Buildings, Mayfield Road, Edinburgh, Scotland

The twelfth annual SCMS forms the first day of the International Centre
for Mathematical Sciences (ICMS) conference on Computational Modelling
in Medicine. The meeting is supported by the UK EPSRC and the London
Mathematical Society, and is open to everyone interested.


M Heil (Manchester, UK)
Computational modelling of pulmonary airway closure and reopening

J Humphrey (Texas A&M, USA)
Modeling biological growth and remodeling in vascular tissue

C Johnson (Utah, USA)
Biomedical computing and visualisation

S Shaw (Brunel, UK)
Adaptive finite elements for model problems in solid
polymer viscoelasticity

P Zunino (Lausanne, Switzerland)
Mathematical modelling of mass transfer in the vascular
system and related clinical applications

Fee: 20GBP (includes lunch) - students can apply for fee to be waived.
To register: fill in the web registration form (deadline 5 September)
Please direct administrative questions to

Penny Davies + David Sloan (Strathclyde), Dugald Duncan (Heriot-Watt).


From: Xiaofan Li <>
Date: Tue, 12 Aug 2003 22:35:40 -0500
Subject: Chair Position at Illinois Institute of Technology


The Department of Applied Mathematics at IIT invites nominations and
applications for the position of Department Chair.

The Department of Applied Mathematics currently consists of 12
tenured/tenure-track faculty with research areas in Applied Analysis,
Computational Mathematics, Discrete Mathematics and Stochastic
Analysis. Because of projected growth, the position provides an excellent
opportunity to shape this small but dynamic department into a leading
applied mathematics department over the next few years. The Department
offers B.S., M.S. and Ph.D. degrees in Applied Mathematics.

Applicants must have established an outstanding research record
in a compatible area, and have demonstrated ability and interest
in teaching. Evidence of leadership skills and prior administrative
experience is desirable. Special attention will be given to applicants
whose research interests are interdisciplinary.

IIT is a private, Ph.D.-granting, research and teaching university
offering degree programs in engineering, science, computer science,
applied mathematics, architecture, business, law, psychology, mathematics
and science education, and design. Current undergraduate and graduate
enrollment is 6,200. IIT is located in the heart of the vibrant city
of Chicago, Illinois. Further information about IIT and the Department
of Applied Mathematics can be found at

An application letter, a curriculum vita and the names of at least three
references should be sent to:

Professor Norman G. Lederman, Chair Applied Mathematics Search Committee
Department of Applied Mathematics 10 W. 32nd Street, Room 208 Illinois
Institute of Technology Chicago, IL 60616 Phone: (312) 567-3658 FAX:
(312) 567-3659 Email:

The search committee will begin reviewing applications on November 1,

Illinois Institute of Technology is an Affirmative Action/Equal
Opportunity employer.


From: Sivaguru Sritharan <>
Date: Fri, 15 Aug 2003 14:08:29 -0600
Subject: Faculty Position at University of Wyoming

University of Wyoming
Department of Mathematics

Tenure Track Position in Information Theory

Applications are invited for a tenure-track position starting August =
2004. The minimum qualifications are an earned Ph.D., significant =
record of accomplishments in research, and evidence of a strong =
commitment to teaching. Candidates with research emphasis in =
Computational Combinatorics, Computational Geometry/Algebraic Geometry, =
or Computational Number Theory with expertise in Information Theoretic =
applications including Coding Theory, Cryptology is preferred. The =
position requires the ability and interest to supervise masters and =
doctoral students, to collaborate with colleagues in the math department =
and faculty in related disciplines, and to develop a competitive, =
externally funded, research program. Review of completed applications =
will begin December 15, 2003. A complete application will consist of a =
letter of application, a complete CV, a statement of research interests =
and accomplishments, and a statement of teaching philosophy. Please =
forward applications to: The Information Theory Search Committee, =
Department of Mathematics, University of Wyoming, Laramie, WY =
82071-3036. Please have at least three letters of recommendations, one =
of which should address the candidate's teaching, sent directly to the =
search committee. For further information please refer to: = UW is an EO/AA employer.


From: Reinout Quispel <>
Date: Thu, 14 Aug 2003 10:10:30 +1000
Subject: Postdoctoral Positions at La Trobe University


Two postdoctoral positions in SCIENTIFIC COMPUTATION are available at
La Trobe University (Melbourne, Australia), in the group of Reinout

The projects concern numerical integration, in particular geometric
integration, of (ordinary) differential equations.

The projects are funded by the Australian Research Council.

Candidates should have a PhD in a related field.

The initial appointment(s) will be for one year, with possible
renewal up to a maximum of five years. Interested candidates should
send a CV to the address below, and should also arrange to have three
or more letters of recommendation sent. Please send all
correspondence to:

Reinout Quispel
Department of Mathematics
La Trobe University
Victoria 3086

For more information, please contact the above address.


From: Yousef Saad <>
Date: Thu, 14 Aug 2003 18:30:23 -0500 (CDT)
Subject: Postdoctoral Position at University of Minnesota

Postdoctoral Associate at the Department of Computer Science
and Engineering, University of Minnesota

One or two Postdoctoral Associate positions are available to work on
research projects related to numerical linear algebra methods in
computational materials science. The projects involve high performance
algorithms (e.g., solving very large eigenvalue problems) in the study
of electronic structures of materials.

Applicants must have a good background in numerical linear algebra and
parallel scientific computing. Knowledge of the equations of quantum
mechanics is a plus but it is not required. Familiarity with partial
differential equations, domain decomposition techniques, sparse
matrices, iterative methods for linear systems and/or eigenvalue
problems, is very desirable, as is experience with parallel
programming. A Ph.D. in Computer Science or a field related to
scientific computing is required.

Send application materials, including the names of up to 3 references,
by e-mail to (or e-mail letter of application and
indicate an URL address where to access resume). There is no deadline
for applying - but the selection process will begin one month after
the posting of this announcement and the positions will remain open
until they are filled.

The University of Minnesota is an equal opportunity educator and


From: Osni Marques <>
Date: Fri, 15 Aug 2003 08:19:05 -0700 (PDT)
Subject: Postdoctoral Position at Lawrence Berkeley National Laboratory


The Lawrence Berkeley National Laboratory has multiple postdoctoral
openings in the development of methods for electronic structure calculations
of nanosystems. Positions are available for methodology development for
large nanosystem atomistic calculations; the development of mathematical/
computational methods for large nanosystems and possibly another position
for high level many body electronic methods.

The hired persons will work with Lin-Wang Wang, Andrew Canning and
Osni Marques of the Scientific Computing Group of the Computational
Research Division at LBNL. The positions are funded by different sources
and will involve collaborations with other researchers in these fields,
such as Alex Zunger (NREL), Jack Dongarra, Victor Eijkhout (University
of Tennessee), Steven Louie, Martin Head-Gordon (LBNL, UC Berkeley),
and Juan Meza (LBNL). A Ph.D degree in physics, chemistry, maths or a
related field is required and experience in ab initio electronic structure
calculations is desired. Interest in algorithmic/mathematical development
and ability for scientific code writing is highly desired.

The position is initially for one year with the possibility of renewal
for up to three years. A highly competitive salary will be offered.
Our division is closely affiliated with the National Energy Research
Scientific Computing Center (NERSC) at LBNL which is the largest civilian
research computer center in the United States with a 6656 processor IBM SP
computer. The Scientific Computing Group is a diverse group working on
various aspects of scientific computation. More information about our
research activities can be found at (
Interested persons should send a curriculum vitae to:

Osni Marques
Andrew Canning
Lin-Wang Wang


From: Anne Cathrine Elster <>
Date: Sat, 16 Aug 2003 19:00:14 +0200
Subject: Postdoctoral Position at Norwegian U. of Science and Tech.

Faculty of Information Technology, Mathematics and Electrical Engineering

Post.doc. at Dept. Of Computer and Information Science within
Ultra Computing (High Performance Computing)

This position focuses on addressing some of the computer science related
problems that arise when applications are scaled up to utilize more than
1000 processing units that need to communicate with each other.

E.g. Amdahl's law states that even if only 1% of the code is serial, one
can never get a speed-up over more than 100. To overcome this, serial
portions of the applications need to be minimized through the use of new
methods and/or through overlapping communication and computations.

New applications may also be of interest. For instance, one class of
interesting future application for highly parallel systems are the
Massively Multiplayer Online Games (MMOGs). MMOGs are parallel simulation
environments where the domain is split up among several thousand processors
(typically clusters) which each handle 100 or more users that affect the
distributed domain. These applications will hence need to address many
problems related to very large clusters and distributed systems.

Contact: Associate Professor Anne C. Elster,

The post.doc. fellowship is for two years. A PhD or similar qualification
is required.

The position is remunerated according to wage levels 50 to 70 on the
Norwegian State salary scale, with gross salary from NOK 343.400 to NOK
494.400 a year, of which 2% is deducted for the State Pension scheme.

The successful applicant must agree to the conditions laid down for public

The national labor force must reflect the composition of the population to
the greatest possible extent. It is therefore a major political objective
to achieve a balance of age and gender and to recruit persons with an
immigrant background. Immigrants are encouraged to apply for this post.

NTNU wants to increase the proportion of women in its scientific posts.
Women are encouraged to apply.

The application must contain information about education, examinations and
previous experience. Certified copies of testimonies and documents must be

Three copies of publications and any other work which the applicant wishes
to be taken into account should also be enclosed. Joint works will be
considered. If it is difficult to specify the input of the applicant in a
joint work, a short summary should be attached outlining the applicant's
input. Please list the submitted publications in the application.

Applications are to be sent to the Norwegian University of Science and
Technology, Faculty of Information Technology, Mathematics and Electrical
Engineering (IME), IT-bygget, Sem S=E6lands vei 9, 7491 Trondheim. The
application deadline is August 21, 2003. The file number for the position
( IME315) is to be clearly stated on the application.


From: ScienceDirect <>
Date: Tue, 12 Aug 2003 10:15:26 -0400 (EDT)
Subject: Contents, Linear Algebra and Applications

Linear Algebra and its Applications Volume 372, Pages 1-345 (1 October 2003)

On a moment problem for rational matrix-valued functions, Pages 1-31
Bernd Fritzsche, Bernd Kirstein and Andreas Lasarow

Perturbation analysis of the matrix equation , Pages 33-51
Ji-guang Sun

A graph theoretical determination of solvable complete rigid Lie algebras,
Pages 53-66
R. Campoamor-Stursberg

Friedland-Hersonsky problem for matrix algebra, Pages 67-78
Wensheng Cao and Xiantao Wang

A generalization of the bounded real lemma, Pages 79-103
Akos Laszlo

Hermite-Biehler, Routh-Hurwitz, and total positivity, Pages 105-110
Olga Holtz

N-matrix completion problem, Pages 111-125
C. Mendes Araujo, Juan R. Torregrosa and Ana M. Urbano

On meet and join matrices associated with incidence functions, Pages 127-153
Ismo Korkee and Pentti Haukkanen

Invertibility preserving linear maps on -subspace lattice algebras,
Pages 155-166
Pengtong Li, Fangyan Lu and Jipu Ma

On the bicommutant for one type of J-symmetric nilpotent algebras in
Krein spaces, Pages 167-180
Vladimir Strauss

On eigenvalues induced by a cone constraint, Pages 181-206
Alberto Seeger and Mounir Torki

A revisitation of formulae for the Moore-Penrose inverse of modified matrices,
Pages 207-224
Jerzy K. Baksalary, Oskar Maria Baksalary and Gotz Trenkler

A parameterization of positive definite matrices in terms of partial
correlation vines, Pages 225-251
Dorota Kurowicka and Roger Cooke

A characterization of Jordan canonical forms which are similar to eventually
nonnegative matrices with the properties of nonnegative matrices, Pages 253-285
Boris G. Zaslavsky and Judith J. McDonald

Linear operators preserving adjoint matrix between matrix spaces, Pages 287-293
Xiao Min Tang

On Hermitian positive definite solutions of matrix equation X+A*X-2A=I,
Pages 295-304
Yuhai Zhang

Rank restricting functions, Pages 305-323
Aharon Atzmon and Allan Pinkus

A note on companion matrices, Pages 325-331
Miroslav Fiedler

Polygonal chains with minimal energy, Pages 333-344
Juan Rada and Antonio Tineo


From: ScienceDirect <>
Date: Tue, 12 Aug 2003 10:15:26 -0400 (EDT)
Subject: Contents, Nonlinear Analysis: Real World Applications

Nonlinear Analysis: Real World Applications Volume 5, Issue 1,
Pages 1-229 (February 2004)

The MHD equations in the case of low conductivity, Pages 1-32
Liudvikas Stupelis

Nonautonomous SEIRS and Thron models for epidemiology and cell biology,
Pages 33-44
Gerd Herzog and Ray Redheffer

Multiple periodic solutions of delayed predator-prey systems with type IV
functional responses, Pages 45-53
Yuming Chen

A mathematical model for induction hardening including mechanical effects,
Pages 55-90
Dietmar Homberg

Global asymptotic stability of Lotka-Volterra competition systems with
diffusion and time delays, Pages 91-104
C. V. Pao

Pattern formation in the Gray-Scott model, Pages 105-121
Jeff S. McGough and Kyle Riley

Existence and uniqueness results to a phase transition model based on
microscopic accelerations and movements, Pages 123-140
Giovanna Bonfanti, Michel Fremond and Fabio Luterotti

Global stability in chemostat models involving time delays and wall growth,
Pages 141-158
V. Sree Hari Rao and P. Raja Sekhara Rao

On the mushy region arising between two fluids in a porous medium,
Pages 159-182
A. Bonnet and R. Monneau

Periodic solutions for a delayed predator-prey model of prey dispersal in
two-patch environments, Pages 183-206
Rui Xu, M. A. J. Chaplain and F. A. Davidson

Global solutions to a degenerate solutal phase-field model for the
solidification of a binary alloy, Pages 207-217
J. -F. Scheid

Almost necessary and sufficient conditions for survival of species,
Pages 219-229
Shair Ahmad and I. M. Stamova


End of NA Digest