- Today's Editor:
- Cleve Moler
- The MathWorks, Inc.
- moler@mathworks.com

- A Meta-question
- Diffusion Tomography
- Three-dimensional Packing Problem
- A Diagonal Matrix Updating Problem
- PDEase Finite Element Software
- Simulation of Devices and Technologies
- Conference on Numerical Methods in Bulgaria
- European Consortium for Mathematics in Industry
- Workshop on Markov Chains
- Workshop on Domain-Based Parallelism and Problem Decomposition
- Postdoctoral Position at U. of Pittsburgh Medical Center
- Postdoctoral Position in Aachen, Germany
- Position at Sandia national Laboratories
- Position at University of New Hampshire
- Contents, Global Optimization
- Contents, Control, Signals, and Systems

-------------------------------------------------------

From: Arne Raeithel <raeithel@rzdspc1.informatik.uni-hamburg.de>

Date: Sun, 6 Feb 1994 19:35:16 +0100 (MET)

**Subject: A Meta-question**

What kind of "digest" is this, I keep asking myself the latter half

of my exposition to >NA Digest< (now over six months). I used to read

"Reader's Digest" back in the fifties; my aunt Lore kept admonishing

me that there is no better way to learn English.

But that publication had questions AND answers, not very convincing ones,

to be sure, but well-written, at least.

In contrast, the na.digest is nothing but a medium to post problems, with

solution attempts going on behind the scenes. Maybe my discipline (psycho-

logy) gravely misleads me in the expectation that it could be otherwise.

Or, I missed a statement of policy by the list-owners saying that

"digest" does not mean to take in nourishing news, rather to ask for them

to be delivered through private two-way channels.

Arne Raeithel

Dept of Psychology

University of Hamburg, Germany.

[Note from Editor: It is certainly true that NA Digest is not the same

kind of publication as Reader's Digest. In the e-mail/network world,

a "digest" is merely an edited collection of contributions obtained from

other sources. In the case of NA Digest, we just collect the items

mailed to the input queue, na.digest@na-net.ornl.gov. We certainly

have no policy against "nourishing" news. -- Cleve]

------------------------------

From: Bill Briggs <wbriggs@copper.Denver.Colorado.edu>

Date: Mon, 7 Feb 94 07:53:46 -0700

**Subject: Diffusion Tomography**

Is anyone familiar with recent work (<2 years) on the diffusion tomography

or infrared imaging problem? Specifically, Grunbaum et.al. have written

on the isotropic problem. Is there any work or efficient algorithms for

the non-isotropic (2-d or 3-d) problem?

Thanks, Bill Briggs

------------------------------

From: Daniel Zwillinger <zwilling@world.std.com>

Date: Tue, 8 Feb 1994 11:24:00 -0500

**Subject: Three-dimensional Packing Problem**

In our work for the Department of Transportation we have been

simulating packed luggage (for the purpose of testing programs that

look at X-ray images for weapons). One step in each simulation is

packing a collection of rectangular parallelepipeds (the objects to be

packed) into another rectangular parallelepiped (the suitcase).

Note that this is not a bin-packing problem, and that each rectangular

parallelepiped can be rotated into any orientation. We believe that

we are aware of the relevant literature, and have found no articles

that directly address this type of three-dimensional packing problem.

Has anyone else considered this problem? We have a working C code

that we would be eager to compare against other codes performing the

same task.

Daniel Zwillinger email: zwilling@world.std.com

63 Greylock Road phone: 617/244-5267

Newton, MA 02160 fax: 617/244-5267

------------------------------

From: Jalel Rejeb <jrejeb@owl.npac.syr.edu>

Date: Wed, 9 Feb 94 16:22:07 EST

**Subject: A Diagonal Matrix Updating Problem**

Consider the following matrix inverse problem:

(I + ACD) X = B

where

A, and C are nonsingular NxN matrices.

D is a diagonal matrix.

B, and X are Nx1 matrices.

And I is the NxN identity matrix.

We need to solve for the unknown vector X.

However, the above matrix equation appears in iterative scheme where at

each new iterative step, only the elements of matrix D are

changed (updated).

Is there a more economical procedure other than taking the inverse

of (I +ACD) at each step of the iteration since only D is changed?

ALL suggestions are appreciated!

Rejeb.

Jalel Rejeb

Northeast Parallel Architectures Center

------------------------------

From: Richard Petti <petti@NEWTON.Macsyma.COM>

Date: Wed, 9 Feb 1994 13:36-0500

**Subject: PDEase Finite Element Software**

MACSYMA INC. SHIPS PDEase FINITE ELEMENT SOFTWARE

Macsyma Inc. is now shipping the first of a new class of software products

for finite element analysis. The new product, PDEase/2 for PC DOS, offers

flexibility, simplicity of input, a lot of automated numerical expertise,

graphics, and a low price.

User-Defined Equations

The user can specify the equations which PDEase solves. The package can solve

a wide range of static and time-dependent systems which combine models of

solid mechanics, heat transfer, reaction/diffusion, fluid mechanics, and

electro/magnetostatics. The program comes with over 50 demonstration problems

covering these disciplines. The current version solves mixed elliptic /

parabolic systems and some hyperbolic systems in 2 1/2 dimensions (meaning

that a third dimension can be present, but the field variables cannot depend

on the third dimension).

Automated Expertise

Users need not specify grid information. The software automatically generates

the finite element grid, refines the model to fit error tolerances (default

tolerances or those set by the user), chooses the appropriate nonlinear

equation solvers to balance solution speed with stability, and adaptively

selects time steps in time-dependent problems. While many options can be

selected by users, the package goes to great lengths to adapt to problems

without human guidance.

Graphics

PDEase creates 2D and 3D graphics under DOS. You can optionally create 3D

graphics under Windows using Macsyma's plot file format and the Macsyma

Graphics Viewer.

Works with Macsyma for Symbolic-Numerical Analysis

PDEase can be used in conjunction with Macsyma, the general-purpose

symbolic-numerical mathematics package. Macsyma can generate and simplify

complicated systems of symbolic equations in any smooth coordinate system.

PDEase can read equations generated by Macsyma. Macsyma Inc. is building into

Macsyma the ability to generate entire batch input files for PDEase.

Price

PDEase is priced under $500 in the U.S. and Canada. Academic and quantity

discounts are available.

System Requirements

PDEase runs on personal computers with 386/387 or greater processors running

DOS, with 4 megabytes of RAM.

A version of PDEase for SPARC workstations running SunOS will ship in March.

For more information contact:

Macsyma Inc.

20 Academy Street

Arlington, MA 02174

tel: 617-646-4550

fax: 627-646-3161

email: info-macsyma@macsyma.com

PDEase is a trademark of SPDE, Inc.

Macsyma is a registered trademark of Macsyma Inc.

------------------------------

From: Grigorii V. Gadiyak <gadiyak@ict.nsk.su>

Date: Mon, 7 Feb 1994 10:33:41 +0700

**Subject: Simulation of Devices and Technologies**

INSTITUTE OF COMPUTATIONAL TECHNOLOGIES

RUSSIAN ACADEMY OF SCIENCES

INSTITUTE OF PHYSICS AND POWER ENGINEERING

INSTITUTE OF NUCLEAR POWER ENGINEERING

FITEMA

THE THIRD INTERNATIONAL SEMINAR ON SIMULATION OF DEVICES AND

TECHNOLOGIES

OBNINSK, RUSSIA

JULY 5-7, 1994

GENERAL TOPICS

- Simulation of semiconductor devices

- Simulation of processes in thin insulator films in strong electric

- Simulation of technologies

- Simulation of Carbon Clusters

- Numerical methods for simulation in micro electronics

REPRESENTATION

We suppose that 60-80 scientists will take part in the Seminar

and 5-10 invited lectures will given.

SPONSORS

Institute of Computational Technologies of Siberian Branch of

the Russian Academy of Sciences

Institute of Physics and Power Engineering

Institute of Mathematical Modeling of Russian Academy of

Sciences

Institute of Nuclear Power Engineering

Phytema

The second Announcement will provide you with a more detailed

information. Please let us know also your telex and the phone number

and e-mail in your letter. We would be very grateful if you inform us

about your decision concerning the participation in the Seminar at

your earliest convenience.

All the correspondence should be sent to the V.P.Ginkin.

Addresses for correspondence:

Bondarenko Sq.1.,Obninsk, Kaluga Region,249020, Russia

Telex: 412509 URAN SU, e-mail: Root@ippe.obninsk.su

or to Prof.G.Gadiyak Ac.Lavrentjev Ave. 6, Novosibirsk, 630090,

Russia

telex 133122 SOVET SU, FAX: 383-2-35-12-42, E-mail Gadiyak@ict.nsk.su

------------------------------

From: Ivan Dimov <NMA94%BGEARN.BITNET@utkvm1.utk.edu>

Date: Mon, 07 Feb 94 17:50:02 BG

**Subject: Conference on Numerical Methods in Bulgaria**

Second Announcement and Call for Papers

3rd International Conference on

Numerical Methods and Applications

NM&A - O(h^3)

August 21-26, 1994, Sofia, Bulgaria

Organizer: Bulgarian Academy of Sciences

Co-organizers: University of Sofia, Technical University - Sofia

The conference aims at providing a forum for presentations and

discussions of recent research in numerical methods and their applications.

Participants from all over the world are expected. The subject of the

conference will range from basic research to applications in physics,

mechanics, engeneering, environmental sciences and other areas, including but

not limited within the following topics:

- Finite Difference and Finite Element Methods

- Boundary Element Method and other Dimension Reduction Methods

- Numerical Methods of Approximation Theory

- Monte Carlo Methods

- Preconditioning Methods

- Parallel Algorithms

- Applications of Numerical Methods

PROGRAM COMMITTEE:

Chairman: Bl. Sendov

A.A. Abramov, O. Axelsson, E. Bontchev, B. Boyanov,

T.F. Chan, I. Dimov, D.J. Evans, M. Kaschiev, R.D. Lazarov, S. Margenov,

G.A. Mikhailov, St. Radev, K.K. Sabelfeld, V. Thomee, M. Vajtersic,

P.S. Vassilevski, L. Xanthis

KEY LECTURERS (having confirmed participation):

A.A. Abramov, O. Axelsson, N.S. Bakhvalov, T.F. Chan, A. Donchev,

D.J. Evans, R. Ewing, R.D. Lazarov, S. McKee, C.A. Micchelli,

G.A. Mikhailov, G.V. Milovanovic, W. Proskurowski, K.K. Sabelfeld,

A.A. Samarskij, M. Sapagovas, O. Spaniol, V. Thomee, R. Vaccaro,

M. Vajtersic, Z. Zlatev, L. Xanthis

CALL FOR PAPERS

The authors should present 3 copies of a camera ready full

length paper (8 pages) by surface mail and the corresponding LaTeX file

by e-mail (or on a diskette) by April 20, 1994.

IMPORTANT DEADLINES:

Submission of registration forms February 20, 1994

Submission of papers April 20, 1994

Preregistration May 31, 1994

The third announcement will provide further information about

accommodation, social events, etc.

ORGANIZING COMMITTEE:

Chairman: I. Dimov

Secretary: A. Karaivanova

T. Dimov, St. Dimova, St. Fidanova, K. Georgiev, R. Georgiev,

T. Gjurov, O. Iliev, N. Kolkovska, S. Margenov, P. Marinov, O. Tonev,

E. Varbanova, L. Zikatanov

The mailing address of the Organizing Committee:

BAS - CICT

Acad. G. Bonchev str., bl. 25A

BG - 1113 Sofia, Bulgagia

e-mail: IVDIMOV@BGEARN.BITNET

fax: (+359 2) 70 72 73

------------------------------

From: Heinz W. Engl <engl@indmath.uni-linz.ac.at>

Date: Tue, 08 Feb 1994 09:57:49 EST

**Subject: European Consortium for Mathematics in Industry**

ECMI 94

The European Consortium for Mathematics in Industry (ECMI)

holds its 8th International Conference at the University of

Kaiserslautern, Germany, between September 6 and 10, 1994

(in cooperation with the German Mathematical Union, DMV).

The objective of the conference is to provide a forum for

the presentation of work on the applications of mathematics

to industrial problems. It will provide a forum for

academics and industrialists to meet and discuss

mathematical problems of mutual interest. It should also

give advanced students a first-hand impression of the

challenges and opportunities for mathematicians in European

industry.

The scientific program will focus mainly on seven topics,

namely mathematical methods in

- aerospace industry

- automotive industry

- chemical industry

- chip production

- construction industry

- finance

- metallurgic processes.

The core of each topic is a special session consisting of

one invited lecture and four selected lectures; contributed

talks related to these topics will be placed on the

afternoon following the respective special session.

Contributed papers and minisymposia in other areas of

industrial mathematics are also welcome.

If interested, please request registration material from the

chairman of the organizing committee

Prof.Helmut Neunzert

Fachbereich Mathematik

Universitaet

POBox 3049

D-67653 Kaiserslautern, Germany

Fax:+49-631-2053052,

E-Mail: ecmi94@mathematik.uni-kl.de

The deadline for the submission of abstracts is April 10.

------------------------------

From: Ilse Ipsen <ipsen@tjarko.math.ncsu.edu>

Date: Tue, 8 Feb 94 14:38:42 EST

**Subject: Workshop on Markov Chains**

Preliminary CALL FOR PAPERS

1995 International Workshop on the

NUMERICAL SOLUTION OF MARKOV CHAINS

North Carolina State University

Raleigh, North Carolina, USA.

January 16-18, 1995

The aims of the workshop are twofold. To foster cooperation among

researchers and practitioners working on diverse aspects of the

numerical solution of Markov chains; and to provide an opportunity

for researchers to present their latest results. The collection of

presentations intends to be an authoritative overview of the field,

including its developments, current status and projections for future

directions. With this in mind, the program will consist of both

invited and contributed papers. The workshop proceedings will be

published.

LIST OF TOPICS:

Applications

Matrix Generation Techniques

Computation of Stationary Probability Vectors:

Direct Solution Methods

Iterative Solution Methods

Recursive Solution Methods (Incl. those of Neuts)

Domain Decomposition Methods

Incomplete Factorizations

Computation of Transient Solutions:

Randomization/Uniformization

ODE Solvers

Krylov Subspace Methods

Approximations:

Aggregation/Disaggregation

Very Large State Spaces

Bounds

Sensitivity Analysis

Stochastic Petri Nets

Stochastic Automata Networks

Markov Reward Models

Infinite Markov Chains

Parallel and Distributed Implementations

Software Demonstrations

WORKSHOP ORGANIZATION:

Chairman: William J. Stewart, NCSU

Local Program Ilse Ipsen, NCSU

Committee: Carl Meyer, NCSU

Erol Gelenbe, Duke

Kishor Trivedi, Duke

Sandy Stidham, UNC

Bob Plemmons, WFU

PARTICIPANTS WILL INCLUDE:

G. Fishman U. of North Carolina, USA

G. Golub Stanford University, USA

W.K. Grassmann U. of Saskatchewan, Canada

U. Krieger Deutsche Bundespost Telekom, Germany

G. Latouche U. Libre de Bruxelles, Belgium

D. Mitra AT&T, Bell Labs, USA

R. Muntz UCLA, USA

M.F. Neuts U. of Arizona, USA

B. Plateau IMAG, France

Y. Saad U. of Minnesota, USA

P. Schweitzer U. of Rochester, USA

P. Semal Philips Research Labs, Germany

G.W. Stewart U. of Maryland, USA

W. Whitt AT&T Bell Labs, USA

IMPORTANT DATES:

June 1, 1994 Deadline for Paper Submission

October 1, 1994 Notification of Acceptance

December 1, 1994 Final Version Due

January 16-18, 1995 Workshop

INSTRUCTIONS:

Submit five copies of a full paper to W.J. Stewart by

June 1, 1994. Papers should be no longer than 20 double

spaced typewritten pages, including tables and figures.

All correspondance should be addressed to

William J. Stewart

Department of Computer Science

Box 8206

N. Carolina State University

Raleigh, N.C. 27695-8206, USA

Phone: (919) 515-7824

FAX: (919) 515-7896

------------------------------

From: Michael Olesen <olesen@s1.msi.umn.edu>

Date: Fri, 11 Feb 1994 14:20:02 -0600 (CST)

**Subject: Workshop on Domain-Based Parallelism and Problem Decomposition**

Workshop on Domain-Based Parallelism and Problem Decomposition

Methods in Computational Science and Engineering

Sponsored by University of Minnesota Supercomputer Institute and

Army High Performance Computing Research Center

In cooperation with the SIAM Activity Group on Supercomputing

April 25-26, 1994

On April 25 and 26, 1994, the Supercomputer Institute will host a

Workshop on Domain-Based Parallelism and Problem Decomposition Methods in Computational Science and Engineering, organized in cooperation with the SIAM Activity Group on Supercomputing and the

Army High Performance Computing Research Center. The symposium,

which will be held at the Supercomputer Institute in Minneapolis,

will focus on problem decomposition algorithms in engineering and

physical sciences, and lecturers will take a broad perspective

suitable for an interdisciplinary audience of engineers, physical

scientists, and applied mathematicians.

There will be a poster session for contributed papers on Monday,

April 25. The abstract deadline in March 18.

The registration fee is $150 fro registrations received prior to

March and $175 after March 1.

For more information or to obtain a registration form, contact one

of the organizers, David Keyes of Yale University, Youcef Saad or

Donald Truhlar of the University of Minnesota, or contact the

Symposium Administrator, Michael Olesen, Supercomputer Institute,

1200 Washington Avenue South, Minneapolis, MN 55415, phone: (612)

624-1356, fax: (612) 624-8861, e-mail: olesen@msi.umn.edu.

Michael J. Olesen

Research Programs Administrator

University of Minnesota

Supercomputer Institute

1200 Washington Avenue South

Minneapolis, MN 55415

office: (612) 624-1356

fax: (612) 624-8861

email: olesen@msi.umn.edu

------------------------------

From: Omar Ghattas <Omar_Ghattas@ptarmigan.warp.cs.cmu.edu>

Date: Tue, 08 Feb 94 20:08:04 EST

**Subject: Postdoctoral Position at U. of Pittsburgh Medical Center**

The Artificial Heart Program, Department of Surgery, University of

Pittsburgh Medical Center seeks an outstanding individual for a

postdoctoral research position in computational fluid dynamics. You

will join an interdisciplinary team of bioengineers and surgeons from

the Artificial Heart Program, and computational scientists from

Carnegie Mellon University, working on computer-based design of a

new-generation artificial heart.

You should have a PhD in engineering or applied mechanics, a strong

background in fluid mechanics, and significant research experience in

CFD. Experience in turbomachinery, viscous incompressible flows,

non-Newtonian fluids, computational optimization, and high performance

computing is desirable, as is familiarity with commercial CFD codes.

Because of the team nature of the project, excellent communication and

interpersonal skills are essential.

If you wish to be considered for this position, please send your

resume and a letter of interest (postscript and latex accepted, ascii

preferred) to ghattas@cmu.edu as soon as possible.

Omar Ghattas

Computational Mechanics Laboratory

Carnegie Mellon University

ghattas@cmu.edu

------------------------------

From: Lutz H. Tack <KE050TA%DACTH11.BITNET@vm.gmd.de>

Date: Wed, 09 Feb 94 14:51:50 MEZ

**Subject: Postdoctoral Position in Aachen, Germany**

POSTDOC POSITION AT THE TECHNICAL UNIVERSITY OF AACHEN, GERMANY

Fellowship to be performed at the RWTH AACHEN within the

European Union (EU) Program "Human Capital and Mobility"

"Numerical and Physical Study of Material Forming Processes"

EU 1991-1994

Close linking of metal-forming technology with fundamental data in the

fields of physical metallurgy and materials science is of crucial

importance in planning and designing processes. The planned project

essentially establishes links of this kind by combining deformation models

(based on the finite element method, FEM) with material models

(mathematical descriptions of developments in the microstructure) to allow

prediction of the local structure of the product during the forming process,

with subsequent design of a material-optimized process by means of

FEM computations with controlled modification of the decisive parameters.

Candidate Profile:

The applicant should have a background in metallurgy and interest in

constitutive modelling. Good experience in Finite Element Methods for

simulation of bulge-forming operations and good knowledge of FORTRAN

are required.

Funding for this position is provided by a grant from the EU, therefore

the candidate must have EU nationality and must not be German.

Research Period:

Six months

Contact:

Kai Karhausen

ke050ta@vm1.rz.rwth-aachen.de

Phone: +49/241/805916

------------------------------

From: Kent Budge <kgbudge@sandia.gov>

Date: Mon, 7 Feb 94 10:16:34 -0700

**Subject: Position at Sandia national Laboratories**

I am looking for prospective candidates to fill a postdoctoral position

at Sandia National Laboratories, Department 1431 (Computational Physics

Research and Development.) Please let me know of any student of whom

you are aware who might be interested and qualified. Feel free to

forward this message to your colleagues.

The successful candidate will share responsibility for the development

of a library of C++ classes useful for a wide variety of numerical

applications, including the solution of partial differential equations,

linear algebra, and visualization. The candidate must have a Ph.D. in

computer science, applied mathematics, or the physical sciences. A

strong background in C++ programming is a must. The candidate must be

comfortable working on parallel computers. The candidate should be

able to work well in a team environment and should be comfortable

interacting with industry partners. Good presentation and technical

writing skills are also important. The candidate must be a U.S.

citizen.

The appointment is for two years.

We wish to fill this position as soon as possible. For more

information, please contact Kent Budge at kgbudge@sandia.gov or by

phone at (505) 844-8244.

------------------------------

From: Kenneth Appel <kia@oregano.unh.edu>

Date: Mon, 7 Feb 94 14:51:16 -0500

**Subject: Position at University of New Hampshire **

The Department of Mathematics of the University of New Hampshire invites

applications for a tenure track (possibly senior) position in applied

mathematics. The Institute for the Study of Earth, Oceans, and Space at

UNH is a source of many interesting problems in applied mathematics and

(funded) collaborative work is possible. It is possible that there will be

a position in pure mathematics if funding becomes available. Strong

commitment to teaching in both undergraduate and graduate courses is

expected. the position(s) will begin in the fall semester of 1994. Review

of applications will begin on April 1, 1994 but applications will be

considered until the positions are filled.

Resume, e-mail address if possible, and three letters of recommendation should

be sent to Kenneth Appel, Chair, Department of Mathematics, University of New

Hampshire, Durham, N.H., 03824 (kia@oregano.unh.edu). The University of New

Hampshire is an EO/AA employer and encourages applications from women and

minority candidates.

------------------------------

From: Pardalos <pardalos@math.ufl.edu>

Date: Wed, 9 Feb 94 14:53:23 EST

**Subject: Contents, Global Optimization**

Table of Contents

JOURNAL OF GLOBAL OPTIMIZATION (Kluwer Academic Publishers)

Vol. 4 No. 1 (1994)

I.M. Bomze and G. Danninger: A finite algorithm for solving general quadratic

problems

F. Schoen: On a new stochastic global optimization algorithm based on censored

observations

W. Baritompa: Accelerations for a variety of global optimization methods

H. Konno, T. Kuno and Y. Yajima: Global minimization of a generalized convex

multiplicative function

J.E. Falk and S.W. Palocsay: Image space analysis of generalized fractional

programs

M.Sniedovich, E. Macalalag and S. Findlay: The simplex method as a global

optimizer: A C-programming perspective

Software Section

Book Review

R. Horst and H. Tuy: Global Optimization - Deterministic Methods (H. Benson)

------------------------------

From: Eduardo Sontag <sontag@control.rutgers.edu>

Date: Mon, 7 Feb 94 09:24:22 EST

**Subject: Contents, Control, Signals, and Systems**

MATH OF CONTROL, SIGNALS, AND SYSTEMS

TABLE OF CONTENTS, Vol. 6, No. 2

Arkadii S. Nemirovskii,

Several NP-hard problems arising in robust stability analysis, pp. 99-105.

J-B. Pomet, R.M. Hirschorn, and W.A. Cebuhar,

Dynamic ouput feedback regulation for a class of nonlinear systems,

pp. 106-124.

Hirosi Sugiyama,

A Sampling Theorem with Equally-Spaced Sampling Points on the Negative Time

Axis, pp. 125-134.

Vincent Blondel and M. Gevers,

The simultaneous stabilizability question of three linear systems is

undecidable, pp. 135-145.

Andrea Baccioti and Paolo Boieri,

Linear stabilizability of planar nonlinear systems, pp. 146-165.

Y. Kannai and G. Weiss,

Approximating signals by fast impulse sampling, pp. 166-179.

Richard Vinter and J. Kotsiopoulus,

Dynamic programming for free time problems with endpoint constraints,

pp. 180-193.

------------------------------

End of NA Digest

**************************

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