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

- Hans Munthe-Kaas Receives Froberg Prize
- Numerical Linear Algebra Preprints Available
- Israel Association for Computational Methods in Mechanics
- Adaptive Grid Generation
- Maximum Likelihood Estimation of Transition Probabilities
- Query on the Square Root Function
- Postdoctoral Position at George Washington University
- Position at Computational Mechanics, Austin, Texas
- Position at University of Jyvaskyla, Finland
- Position at University of Bergen, Norway
- Position at Beam Technologies, Ithaca, NY
- PhD Studentship at Liverpool, UK
- Contents, IMA J. Numerical Analysis
- Contents, Computational and Applied Mathematics

**URL for the World Wide Web:**
http://www.netlib.org/na-net/na_home.html
-------------------------------------------------------

From: Ulla Miekkala <ulla@lammio.hut.fi>

Date: Tue, 11 Jun 96 15:07:00 +0200

**Subject: Hans Munthe-Kaas Receives Froberg Prize**

The Carl-Erik Froberg Prize for young Nordic authors was awarded on

June 6th, 1996, in the 22nd Nordic Congress of Mathematicians held

in Lahti, Finland, to

Hans Munthe-Kaas, Norway

for his excellent article

"Lie-Butcher theory for Runge-Kutta methods".

The Prize, 25000 Dkr, is given in even numbered years to a young

Nordic author of a paper published in BIT Numerical Mathematics.

The Prize has previously been given as follows:

1994 Ulla Miekkala, Finland

1990 Per Christian Hansen, Denmark

1988 Gunilla Kreiss, Sweden.

The prize committee consisted of members of the editorial board of BIT.

Olavi Nevanlinna

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

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

Date: Thu, 6 Jun 1996 19:32:22 -0400

**Subject: Numerical Linear Algebra Preprints Available**

The following papers are available in postscript format from:

http://www4.ncsu.edu/~ipsen/public/info.html

S.C. Eisenstat and I.C.F. Ipsen: Relative Perturbation Results for

Eigenvalues and Eigenvectors of Diagonalisable Matrices

I.C.F. Ipsen: Computing an Eigenvector with Inverse Iteration

J.M. Banoczi, N. Chiu, G.E. Cho, and I.C.F. Ipsen: The Influence of the

Right-Hand Side on the Accuracy of Linear System Solution

-- Ilse

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

From: Isaac Harari <harari@eureka.eng.tau.ac.il>

Date: Mon, 10 Jun 1996 19:32:40 +0300

**Subject: Israel Association for Computational Methods in Mechanics**

The WWW home page of the Israel Association for Computational Methods in

Mechanics (IACMM), an affiliate of the International Association for

Computational Mechanics (IACM), is accessible via URL

http://www.eng.tau.ac.il/~harari/IACMM/iacmm.html

We invite the participation of the computational community within Israel

and abroad.

Isaac Harari

Department of Solid Mechanics, Materials and Structures

Tel Aviv University

69978 Ramat Aviv, ISRAEL

Phone: +972-3-640-9439

Fax: +972-3-640-7617

e-mail: harari@eng.tau.ac.il

WWW: http://www.eng.tau.ac.il/~harari/

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

From: Tom Hoffend <trhoffend@mmm.com>

Date: Tue, 11 Jun 1996 08:11:33 -0500

**Subject: Adaptive Grid Generation**

I am searching for information, in particular major references and/or

review papers and books, concerning method/strategies/analysis of

adaptive grid generation for finite difference methods for systems of

reaction/advection/diffusion equations. I am looking at a class of

problems where very sharp fronts develop.

I am starting with some references from the chemical engineering

literature and would like to find out what is happening in the applied

mathematics community. Thank you.

Tom Hoffend

Thomas R. Hoffend Jr.

3M Company

3M Center Bldg. 201-BN-31

St. Paul, MN 55144-1000

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

From: Rajiv Kamilla <rkamilla@insti.physics.sunysb.edu>

Date: Tue, 11 Jun 1996 16:51:10 -0400 (EDT)

**Subject: Maximum Likelihood Estimation of Transition Probabilities**

MAXIMUM LIKELIHOOD ESTIMATION OF TRANSITION PROBABILITIES

Hello -- Any suggestions or advice with respect to the problem

indicated below would be immensely appreciated.

Thank you very much in advance.

Let us assume that there are N particles which populate

n states (n << N). These n states have different degrees of

stability of occupation and we are interested in estimating the

T_{n x n} matrix where T_{ij} ( i and j run over all indices

1 to n) indicates the transition probability from state i to state j

(viz. T_{ij} == Probability Transition from i --> j )

The (in)stability of occupation of state i (for all i=1,2,3...n)

n

__

S_i = \ (T_{ij}) (j not equal to i)

/_

j=1

Now let's say we have a time series that indicates

the different states occupied by each of the N

particles as a function of time.

What are the relevant parameters one should calculate

(with the associated likelihood indicators) that would

provide an unbiased estimate of the T_{ij} (i,j=1,2,...n)?

Can any Maximum Likelihood analysis be associated in the

estimation of T_{ij} ?

The time series is finite and large N or large time

approximations are not immediately obvious or valid.

The T_{ij} would need to be associated with a confidence

margin.

Can a optimal time of transition t_{ij} be associate

with the tranisition T_{ij} ?

Rajiv Krushna Kamilla email address: rkamilla@insti.physics.sunysb.edu

Physics Dept. Phone: (516) 632-8172(work)

SUNY@Stonybrook (516) 331-3978(home)

NY-11794-3800 WWW:http://insti.physics.sunysb.edu/~rkamilla/

USA

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

From: Frank D Uhlig <uhligfd@mail.auburn.edu>

Date: Thu, 13 Jun 1996 09:13:59 -0500 (CDT)

**Subject: Query on the Square Root Function**

Query on the SQUARE ROOT FUNCTION:

How many multiplications/divisions does evaluating one real (or complex)

square root sqrt(a) take ?

How is it done at the state of the art level?

There are several Newton iteration algorithms available.

The quadratically convergent one takes 2 mult/divides and converges in 5

to 13 iterations for 0 <= |a| <= 2 with my initial 'dumb guess' of x_0 = a.

The cubically convergent one takes 5 mult/divides, converging in 3 to 7

iterations with the same dumb start x_0 = a.

quadratic Newton iteration for x = sqrt(a):

x_{n+1} = (x_n + a/x_n)/2

cubic Newton iteration:

x_{n+1} = (x_n*(x_n^2 + 3*a)/(3*x_n^2 + a)

Am I correct to give a square root the mult/divide equivalent of around

18 'old' flops?

Am I correct to give the quadratic one the nod? (about twice as slow, on

average, but 2.5 times cheaper in each step.)

I realize that the initial guess x_0 is a flop saver; how can one

judiciously guess?

Can one use a hybrid method: start with quadratic Newton, followed by

a cubic final afterburner?

What about square roots of complex numbers? I noted similar convergence

of the same iterations above over the complexes. Any better schemes there?

Initial guesses?

Incidentally, MATLAB seems to use the quadratic method; my iterative

results in quadratic mode seem to agree more closely with the MATLAB

square root function than with those from the cubic method.

Thanks to all that can help me with this; it must be old hat for someone

out there, but not for me ...

Frank Uhlig

uhligfd@mail.auburn.edu

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

From: Cathrine Mavriplis <mavripli@seas.gwu.edu>

Date: Fri, 7 Jun 1996 15:33:36 -0400 (EDT)

**Subject: Postdoctoral Position at George Washington University**

POSTDOCTORAL POSITION AVAILABLE 7/1/96

Center for Combustion and the Environment

The George Washington University

Washington DC

The newly-formed Center for Combustion and the Environment at the

George Washington University has an opening for a Postodoctoral

Research Associate in the area of simulation of combustion

processes. The immediate objective is for the candidate to perform

spectral element simulations of time-varying laminar diffusion flames

to investigate the effect of vortex-chemistry interaction on pollutant

production. The ideal candidate would have significant experience in

developing computational fluid dynamic algorithms and have some

knowledge of combustion, including familiarity with the CHEMKIN

computational package. This position requires a Ph.D. in Engineering

or the Sciences. The candidate will also be expected to act as a

liaison between the computational research group of the center housed

in Mechanical Engineering and the experimental research group of the

center housed in Chemistry. Additional experience in parallel

programming would be considered an asset.

Interested persons should send their resume to:

Prof. C. Mavriplis

CMEE T713

801 22nd ST NW

George Washington University

Washington DC 20052

or by fax to:

(202) 994-0238

or by email to:

mavripli@seas.gwu.edu

GW is an Equal Opportunity Employer

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

From: Olivier Hardy <olivier@comco.com>

Date: Mon, 10 Jun 1996 09:15:22 -0500

**Subject: Position at Computational Mechanics, Austin, Texas**

Computational Mechanics Co., Inc. (COMCO), is a small high-tech

engineering consulting and software development company based in

Austin, Texas. COMCO specializes in application of adaptive finite

element methods in many areas of computational mechanics including

fluid and solid mechanics.

COMCO has an immediate opening for an application development engineer

in the areas of computational fluid dynamics (CFD) and numerical heat

transfer. The successful candidate must have at least a MS in engineering

with strong background in CFD and heat transfer applications, must have

good knowledge of finite element methods and variational formulations

as applied to CFD and must be proficient in C programming language.

Self motivation, effective communication skill and team work spirit are

also essential.

In addition, multi-disciplinary CFD application experience, familiarity with

finite volume/finite difference techniques, graduate level knowledge of

continuum mechanics and linear algebra, hands-on experience with commercial

CFD and mesh generation codes, and one to two years of relevant industry

experience will be pluses.

Please send resumes to:

Attn: CFD-Resumes

The Computational Mechanics Co., Inc. (COMCO)

7701 N. Lamar, Suite 200

Austin, Tx 78752

Fax: 512 467 1382

Resumes using plain text may also be sent via e-mail to

"cfd-resumes@comco.com". No phone calls please.

Additional information on COMCO may be found on the internet at

"http://www.comco.com".

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

From: Pekka Neittaanmaki <pn@math.jyu.fi>

Date: Tue, 11 Jun 1996 12:58:30 +0300

**Subject: Position at University of Jyvaskyla, Finland**

Professorship in Telecommunication

The University of Jyvaskyla in cooperation with Telecom Finland seeks

Professor position for its new Telecommunications Program (TP) for

teaching, research and development. The successful candidate must

demonstrate a strong commitment to graduate education and research

projects in Master School in Information Technology. Additionally,

he/she is expected to develop a skillful research program in partnership

with Telecom Finland.

Fields of Teaching/Research/Development

The professorship position is eligible in one of the following areas in

telecommunications networks design:

Mathematical Modelling of Communication Systems

Digital and Adaptive Signal Processing

Electronics and Hardware Design of Communication Systems

Network Management and Computer Controlled Interfaces

Database Processing of Automated Exchanges

Intelligent Networks and Mobile Phone Networks

Although applications are welcome from anyone who holds a Ph.D. in

Telecommunication, Computer Science, Electrical Engineering or Computer

Systems Engineering, the Telecommunications Program has a particular

interest in candidates who are qualified in electronics and telecommunication

systems.

The actual staff of the Telecommunications Program is expected to offer

M.S. and PhD degrees in telecommunication systems. More information about

the city, the university and the department can be found in the WWW

pages:

http://www.infoma.jyu.fi

http://www.math.jyu.fi

http://www.jsp.fi/jsp

http://www.jkl.fi

Applicants should submit a detailed resume and the names of at least

three references to: Professor Pekka Neittaanmki, Department of Mathematics,

University of Jyvaskyla, FIN-40351 Jyvaskyla, FINLAND, Tel. (358)-41-602732,

Fax. (358)-41-602731, Email: pn@tarzan.math.jyu.fi

Applications must be received by 14th June, 1996.

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

From: Hans Munthe-Kaas <Hans.Munthe-Kaas@ii.uib.no>

Date: Wed, 12 Jun 1996 10:06:20 +0200

**Subject: Position at University of Bergen, Norway**

RESEARCHER - Object oriented numerics/ seismic modeling

At Department of Informatics, University of Bergen, Norway, a position

as a researcher is available in the period September 1. 1996 to July 1.

1997. There are possibilities for continuation after this date.

The applicants should hold a Ph.D. or master degree, in either

mathematics or computer science.

The person to be employed will work in a project related to seismic

modeling, financed through the norwegian research council and several oil

companies. The goal is to develop integrated tools for geological,

geophysical and seismic modeling, and involves researchers from different

fields and from the industry. The particular task for this position is the

development of code for modeling elastic waves on sequential and parallel

computers. The code is build around the SOPHUS library, which is an object

oriented C++ library for solving general tensor field equations being developed

as a part of this and other projects.

In the evaluation of the applicants, we will emphasize experience in object

oriented program design, and a good background in numerical analysis or other

areas of mathematics.

The salary depends on qualifications and experience. For candidates holding a

master degree it is in the range 206,000 - 280,000 NKr, and for Ph.D. in

the range 269,000 - 312,000 Nkr. (6.6 Nkr ~ 1 US $).

Applicants should send their vitae and references by _email_or_fax_

to the below address _as_soon_as_possible_. Send verified copies in paper

mail. Applications received after June 27. will probably not be considered.

Paper mail:

Associate Professor

Hans Munthe-Kaas

Department of Informatics

University of Bergen

N-5020 Norway

Email: hans@ii.uib.no

Fax: +47 55584199

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

From: Rick Palmer <rick@beamtech.com>

Date: Thu, 13 Jun 1996 16:34:02 -0400

**Subject: Position at Beam Technologies, Ithaca, NY**

Title: Numerical Software Development Specialist.

Start Date: Immediately, 5/13.

Location: Ithaca, NY.

Employer: BEAM Technologies, Inc.

Responsibilities: Develop components of innovative software tool for

partial differential equation simulation (PDESolve); develop

applications using PDESolve; support PDESolve users developing

applications (both inside and outside of BEAM); Participate in

scientific research projects involving the development of new

PDE-based algorithms and applications.

Qualifications and Experience:

Ph.D. in applied math. or engineering with at least two

years of experience.

Solid background in finite elements as witnessed by writing at least

one complex nonlinear PDE simulation code.

Excellent computer and software development skills.

Excellent numerical analysis skills.

At least two years of experience developing numerical software in C++.

Proven ability to work in a team.

Excellent people, communication, and instructional skills.

Motivation and desire to help users.

Salary and Benefits:

Competitive salary up to $60K commensurate with experience

and qualifications.

Full benefits including 401K plan, health, vacation, etc.

Stock option plan.

Send resume to:

President

c/o PDE search

BEAM Technologies, Inc.

110 N. Cayuga St.

Ithaca, NY 14850

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

From: K. Chen <K.Chen@liverpool.ac.uk>

Date: Wed, 12 Jun 1996 17:05:30 +0100

**Subject: PhD Studentship at Liverpool, UK**

Applied Mathematics Division

Department of Mathematical Sciences

The University Of Liverpool

PhD Studentships in Computational Mathematics

http://www.liv.ac.uk/~cmchenke/positions.html (on-line application)

A Liverpool University Studentship is available for a prospective

PhD student to be supervised by Dr Ke CHEN (with collaborations)

email = k.chen@liv.ac.uk

beginning from October 1996. The PhD would be in the area of numerical

solution of partial differential equations,

investigating adaptive meshing and other related CFD questions.

Applicants should be currently enrolled in, or have completed, the final

year of an undergraduate degree in Mathematics. An MSc would be an

advantage, but is not required. As well as an interest in

Computational Mathematics (Numerical Analysis),

applicants should have a willingness to work on both analysis and

practical problems. Applications include circuit breakers,

semiconductor diffusion or wave scattering.

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

From: I.Duff@letterbox.rl.ac.uk (Iain Duff)

Date: Fri, 7 Jun 96 17:00:16 BST

**Subject: Contents, IMA J. Numerical Analysis**

IMA JOURNAL OF NUMERICAL ANALYSIS --- Volume 16, Number 3.

Meerbergen K. and Roose D

Matrix transformations for computing rightmost eigenvalues of large

sparse non-symmetric eigenvalue problems.

Girault V and Lopez H

Finite-element error estimates for the MAC scheme

Jimack P K

Optimal eigenvalue and asymptotic large-time approximations using the

moving finite-element method.

Milner F A and Park E-J

Mixed finite-element methods for Hamilton-Jacobi-Bellman-type equations.

Al-Zanaidi M, Grossmann, C., and Voller R L

Monotonous enclosures for the Thomas-Fermi equation in the isolated

neutral atom case.

Aston P J and Sittampalam A G

Numerical methods for steady-state mode interactions.

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

From: Carlos A. de Moura <demoura@iprj.uerj.br>

Date: Mon, 10 Jun 96 10:04:37 EST

**Subject: Contents, Computational and Applied Mathematics**

COMPUTATIONAL and APPLIED MATHEMATICS

Ed: Sociedade Brasileira de Matematica Aplicada e Computacional-SBMAC

and Birkhauser Boston

Editors: Jim Douglas Jr.; C.S. Kubrusly; C.A. de Moura

Contents

Mat.Aplic.Comp. \ Comput.Appl.Math. 15(1), 1996

Martel,Y (1-17):

A NONLINEAR AIRY EQUATION

Ben-Yu,G; Xun,L; Vazquez,L (19-36):

A LEGENDRE SPECTRAL METHOD FOR SOLVING

THE NONLINEAR KLEIN-GORDON EQUATION

Banks,SP; Moser,A; McCaffrey,D (37-54):

LIE SERIES AND THE REALIZATION PROBLEM

Cash,JR; Silva,HHM (55-75):

ITERATED DEFERRED CORRECTION FOR LINEAR

TWO-POINT BOUNDARY VALUE PROBLEMS

Thompson,M; Rubio,O (77-94):

THE HAUSDORFF DIMENSION OF FUNCTIONALLY

INVARIANT SETS FOR THE MHD-EQUATIONS

WITH THERMAL DISPERSION

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

End of NA Digest

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