- Today's Editor:
- Tamara G. Kolda
- Sandia National Labs
- tgkolda@sandia.gov

- Morally triangular matrices
- Robust Mathematical Modeling Program, Invitation to Institutions
- MIMS Workshop on Large Graphs and Networks, Sep 2007
- Numerics in Finance, Nov 2007
- Fields Institute Events, 2007-2010
- Copper Mountain Conference on Iterative Methods, Apr 2008
- Workshop on biological networks, Oct 2007
- Full professor position in Optimization at TU Delft
- Tenure track positions in applied math at Clarkson University
- Postdoctoral researcher - reservoir modeling and simulation
- Postdoctoral Research Fellowship at Birmingham (UK)
- Contents, Special Issue, Int J of Computer Mathematics, Vol 84 Issue 8 2007
- Contents, Journal of Scientific Computing
- Contents, ACM Transactions on Mathematical Software
- Subscribe, unsubscribe, change address, or for na-digest archives:
- http://www.netlib.org/na-net

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

From: Tim Davis <davis@cise.ufl.edu>

Date: Fri, 31 Aug 2007 09:53:28 -0400

**Subject: Morally triangular matrices**

Cleve Moler defines a matrix A as "morally triangular" if

there exists a permutation P such that P*A is lower triangular.

In contrast, John Gilbert defines a matrix A as "psychologically

triangular" if there exist permutations P and Q such that P*A*Q

is lower (or upper) triangular. Morally triangular matrices

arise in MATLAB when you do [L,U]=lu(A); in this case, the partial

pivoting is captured in L, which is morally triangular. The right

factor, U, is simply triangular. Backslash then detects whether

or not L is morally triangular when computing x=L\b, finds the

permutation, and does the forward solve.

Thus, in MATLAB:

A = sprand (100,100,0.1) ;

b = rand (100,1) ;

[L,U] = lu (A) ;

spparms ('spumoni',2) ; % turn on sparse diagnostics

x = L\b ;

you get the following output:

sp\: bandwidth = 93+1+89.

sp\: is A diagonal? no.

sp\: is band density (0.34) > bandden (0.50) to try banded solver? no.

sp\: is A triangular? no.

sp\: is A morally triangular? yes.

sp\: permute and solve.

I have a hard time keeping track of the difference between

moral triangularity and psychological triangularity, and I suspect

others who read this digest do too. Thus, in honor of Cleve and

John, I wrote a helpful tool for remembering the difference:

Tweedle Tril and Tweedle Triu, by T.D.

I'm Tweedle Tril, he's Tweedle Triu,

We're the factors of sparse LU.

My brother: right and triangle;

Me? Triangularly moral.

I like my pivots small and sweet,

but the little pivots try me.

I watch my cholesterol and yet,

my chol ist err'd all high, I bet.

My brother likes his pivots large;

to which he's absolutely partial,

they say it keeps condition low,

but to him they just give fill-in.

The pivots to which he's partial

keep my condition suitable.

My doctors math all want to show

condition number very low.

We're quite complete, as you can tell;

no preconditions, none at all.

Factor fine with no conditions,

yet we love those graph partitions.

And when at last we come to rest

and find solutions you can test,

Take norm resid and see it's best,

and note how low is our condest.

I don't think morally triangular matrices are related to the

definition of "horror matrices", but in case they do, you can

find the definition at

http://www.cise.ufl.edu/~davis/Horror_matrices.html#horror .

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

From: "Bernard Beauzamy" <Bernard.Beauzamy@scmsa.com>

Date: Tue, 28 Aug 2007 15:08:53 +0200

**Subject: Robust Mathematical Modeling Program, Invitation to Institutions**

Dear Colleagues,

We are presently developing a research program called "Robust Mathematical

Modeling"; it started 3 years ago and includes several institutions, both in

the US and in Europe (companies and academia). The general objective of the

program is to develop tools which can handle the uncertainties occurring in

real life problems : on the data, on the laws, on the objectives. Please see

http://www.scmsa.com/robust.htm for a general description of the program.

This program is open : any institution can freely participate. We would like

more institutions (public or private, companies or academic) to join the

program. The benefits would be :

- each institution organizes regularly a local colloquium, in which are

presented the users' needs : so, having more colloquia, we would have more

experiences to share ;

- contributing to the list of tools which are already present on the web

site ;

- criticizing the existing tools. The web site appears as some kind of open

publication, in which participants can freely add comments to the available

papers.

- participating to the PhD program which is associated with the RMM program

: students should travel to several countries and get various experiences.

Interested people should send an email to

Bernard.Beauzamy@scmsa.com

Best regards,

Bernard Beauzamy

University Professor (ret.)

Chairman and CEO, Societe de Calcul Mathematique S. A.,

111 Faubourg Saint Honore

75008 Paris, France

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

From: Nick Higham <Nick.Higham@manchester.ac.uk>

Date: Thu, 30 Aug 2007 12:23:31 +0100

**Subject: MIMS Workshop on Large Graphs and Networks, Sep 2007**

The Manchester Institute for Mathematical Sciences (MIMS) is hosting a

"Workshop on Large Graphs and Networks: Matrix Algorithms and

Applications" on Tuesday September 11, 2007, 2-4.30pm.

This is an informal afternoon workshop covering new developments in

matrix-based algorithms for large graphs and networks.

The speakers are

Des Higham (University of Strathclyde).

"Spectral Algorithms for Biological Networks"

Ilse Ipsen (North Carolina State University)

"The Mathematics Behind Google's PageRank"

Abstracts and further information are at

http://www.mims.manchester.ac.uk/events/workshops/graphnet07/

---Nick Higham

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

From: Kees Oosterlee <C.W.Oosterlee@math.tudelft.nl>

Date: Tue, 28 Aug 2007 13:02:42 +0200

**Subject: Numerics in Finance, Nov 2007**

Call for Papers and Announcement for a Financial Workshop:

Workshop "Numerics for Finance", at the Commerzbank in Frankfurt am

Main, Germany, November 5th and 6th 2007.

Invited speakers:

Peter Forsyth (Waterloo, Canada),

Mike Giles (Oxford, UK),

Peter Kloeden (Frankfurt, Germany) and

Ludger Overbeck (Giessen, Germany).

In this workshop we will present the latest advancements in numerical

methods for financial applications. Techniques include, but are not

limited to,

-- PDE methods for pricing financial derivatives;

-- Recent development in monte Carlo methods;

-- Numerical techniques in risk management.

Please send your one page abstract before September 15th to

c.w.oosterlee@cwi.nl, or wittum@uni-hd.de Acceptance will be announced

before October 1st 2007.

The workshop fee will be 150 Euro for academic researchers, 300 Euro for

industrial participants.

The Workshop Organizers:

Cornelis Oosterlee (CWI, Amsterdam), Ruediger Seydel (Cologne),

Christoph Wagner (Frankfurt) and Gabriel Wittum (Heidelberg).

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

From: Carl Riehm <criehm@fields.utoronto.ca>

Date: Thu, 30 Aug 2007 09:52:40 -0400

**Subject: Fields Institute Events, 2007-2010**

Regular Seminars of possible interest to NA-net subscribers:

Actuarial Science & Financial Mathematics Group Meetings

http://www.fields.utoronto.ca/programs/cim/07-08/actuarialmath/index.html

Colloquium/Seminar in Applied Mathematics

http://www.fields.utoronto.ca/programs/scientific/07-08/applied_math/index.html

Fields Industrial Optimization Seminar

http://www.fields.utoronto.ca/programs/cim/07-08/optimization_seminar/index.html

PRMIA Risk Management Seminars

http://www.fields.utoronto.ca/programs/cim/07-08/PRMIA/index.html

Seminar Series on Quantitative Finance

http://www.fields.utoronto.ca/programs/cim/financial_math/finance_seminar/07-

08/index.html

Some specific events during the next year:

May 20-23, 2008, Fifth International Workshop on Taylor Model Methods

http://www.fields.utoronto.ca/programs/scientific/07-08/taylor-model/index.html

May 21-23, 2008, Symposium on Dependent Data Structures

http://www.fields.utoronto.ca/programs/scientific/07-08/dependent/index.html

August 11-15, 2008, Fields-MITACS Industrial Problem-Solving Workshop

http://www.fields.utoronto.ca/programs/scientific/08-09/FMIPW/

Future Fields thematic programs are

2007 (Fall) Operator Algebras

2008 (Winter/Spring) New Trends in Harmonic Analysis

2008 (Fall) Arithmetic Geometry, Hyperbolic Geometry and Related Topics

2009 (Winter/Spring) O-Minimal Structures and Real Analytic Geometry

2010 (Winter/Spring) Financial Mathematics

Details of all our programs can be found on our website

http://www.fields.utoronto.ca/

To be informed of upcoming events, please subscribe to our mailing list at

http://www.fields.utoronto.ca/maillist

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

From: Copper Mtn Conference <Copper.Conference@Colorado.EDU>

Date: Thu, 30 Aug 2007 10:40:16 -0600 (MDT)

**Subject: Copper Mountain Conference on Iterative Methods, Apr 2008**

ANNOUNCING:

Tenth Copper Mountain Conference on Iterative

Methods

April 6 - 11, 2008

Copper Mountain, Colorado, USA

ORGANIZED BY:

Front Range Scientific Computations, Inc.

CO-ORGANIZED BY:

The Center for Applied Scientific Computing,

Lawrence Livermore Nat'l Lab

The University of Colorado

The University of Maryland

IN COOPERATION WITH:

The Society for Industrial and Applied

Mathematics

TENTATIVE SPONSORS:

DOE, NSF, IBM, Boeing, LANL, LLNL, Sandia

THEMES:

Stochastic PDEs and Uncertainty

Page Rank and Markov Chains

Inverse Problems and Regularization

Optimization

Systems of PDEs

Hardware Effects / Multicore Architectures

SPECIAL FEATURES:

Student Paper Competition. Travel and lodging

assistance will be awarded to students and

new PhDs judged to have submitted the best

research papers.

Workshops - Informal Topical Discussions

Preliminary Proceedings

CONFERENCE DEADLINES:

Student Papers January 10, 2008

Author Abstracts February 1, 2008

Early Registration March 2, 2008

Guaranteed Lodging March 6, 2008

FOR FURTHER INFORMATION:

Please access our website at:

http://amath.colorado.edu/faculty/copper

- or contact -

Annette Anthony

FRSC

copper@colorado.edu

(303) 554-1232 or (480) 332-2026

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

From: Fatihcan Atay <atay@member.ams.org>

Date: Sun, 2 Sep 2007 13:37:49 +0200

**Subject: Workshop on biological networks, Oct 2007**

Genetic and Biological Networks: Models, Dynamics, and Simulations

A satellite workshop of the ECCS'07: European Conference on

Complex Systems, 1-5 October 2007, Dresden, Germany

Biological systems show emerging functional properties originating from their

many interacting units and their inherent multi-level structure. In recent

years, biologists, physicists, mathematicians, and computer scientists have been

joining efforts in order to understand the different aspects of the collective

phenomena exhibited by aggregates of cells and by regulatory networks. The aim

of this meeting is to bring together experts in such fields to discuss and

explore our understanding of complex biological networks and their applications

in the life sciences. Specific topics include, but are not limited to,

gene-regulatory, molecular, and metabolic networks, bioinformatics, population

dynamics, neural systems, evolutionary dynamics, and mathematical biology.

Interested researchers who wish to contribute a talk are invited to send a title

and abstract to fatay@mis.mpg.de

For further information please visit:

http://personal-homepages.mis.mpg.de/fatay/eccs07

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

From: Kees Roos <c.roos@tudelft.nl>

Date: Mon, 27 Aug 2007 12:41:27 -0400

**Subject: Full professor position in Optimization at TU Delft**

Optimisation is one of the key professorships at Delft Institute of Applied

Mathematics (DIAM), which forms an integral part of the Faculty of

Electrical Engineering, Mathematics and Computer Science (EEMCS). The Chair

lies at the centre of the mathematical research and teaching curriculum for

Applied Mathematics . In addition to research and teaching responsibilities,

the Professor will strengthen the role of the group in the Delft Research

Centre for Computational Science and Engineering and the various BSc and MSc

programmes.

The candidate should be a university graduate with a proven track record in

Optimisation, with specific emphasis on continuous optimisation and on the

algorithmic component of the field: the efficient solution of large-scale

optimisation problems. He/she has a PhD in Mathematics or a related

discipline and has published pioneering articles in top research journals.

Those applying will be enthusiastic team players, willing to make

significant contributions to research and education, with excellent teaching

skills, an inquiring mind, and good managerial abilities. Delft University

of Technology is a bilingual organisation; a good command of English

(written and oral) is essential, while good Dutch is also preferred.

The extent of the position is a maximum of 38 hours per week (1 FTE). The

starting salary for this position is commensurate with experience and

qualifications. The maximum monthly salary is 6,841 to 8,259 per month

gross, based on a full-time appointment. Benefits and other employment

conditions are in accordance with the Collective Labour Agreement for Dutch

Universities.

TU Delft strives to increase the number of women in higher academic

positions; women are thus especially encouraged to apply.

For further details on the position you are welcome to contact Prof. A.W.

Heemink, phone: + 31 (0)15 27 85813, e-mail: A.W.Heemink@tudelft.nl.

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

From: Peter Turner <pturner@clarkson.edu>

Date: Mon, 27 Aug 2007 11:10:09 -0400

**Subject: Tenure track positions in applied math at Clarkson University**

The Division of Mathematics and Computer Science (www.clarkson.edu/mcs)

invites applications for two tenure-track position in applied mathematics

starting in August 2008. One position will be filled at the Associate or

Full Professor level, the other is expected to be filled at the Assistant

Professor level.

We are especially interested in candidates with expertise in computational

areas of applied mathematics, including statistics, or dynamical systems, but

all areas of applied mathematics will be considered. Responsibilities will

include teaching undergraduate and graduate level mathematics courses, and

directing graduate students. For the assistant professor level, minimum

requirements are a Ph.D. in mathematics by the date of appointment,

demonstrated excellence in both research potential and teaching ability, and

fluency in English. In addition, the candidate should be able to interact

with other faculty in the department and the university. For the senior

position, research, including a record of funding, and teaching records

commensurate with such an appointment will be required.

Applications including vita and three reference letters should be submitted

to Prof. P.A. Turner, Department of Mathematics and Computer Science,

Clarkson University, Potsdam, NY 13699-5815. Completed applications will be

reviewed starting immediately. Women and minorities are urged to apply.

Clarkson University is an AA/EOE Employer. (Pos. # 13-07, senior, Pos. # 14-

07, junior)

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

From: AarnesJrg <Jorg.Aarnes@sintef.no>

Date: Thu, 30 Aug 2007 13:45:49 +0200

**Subject: Postdoctoral researcher - reservoir modeling and simulation**

SINTEF ICT

SINTEF ICT is an institute within the SINTEF group with departments in

Trondheim and Oslo. SINTEF ICT undertakes contract research and

development projects for industry and the public sector in the area of

information and communication technology. We collaborate closely with

NTNU and the University of Oslo. SINTEF ICT has approx. 260 employees

and collaborates with a large number of industries and academic

institutions in Norway and abroad.

The Department of Applied Mathematics at SINTEF ICT is expanding due

to an increased project portfolio. Our activities include modelling

and simulation of petroleum reservoirs, optimisation methods for

complex planning and scheduling applications, parallel computing,

visualisation, and geometric modelling. We are currently seeking an

innovative postdoctoral researcher with excellent mathematical and

computational skills wanting to contribute to high-quality research in

a young and creative research group.

The postdoctoral researcher will take part in a research project

funded by the Research Council of Norway, NTNU, and Shell. The project

aims to establish a proof-of-concept in an industrial setting for

multiscale reservoir simulation (see

http://www.math.sintef.no/GeoScale for some of our current

research). Reaching this goal requires a collaborative effort from a

dedicated team of researchers with advanced mathematical and

computational skills.

Qualifications:

· doctoral degree in applied mathematics, scientific computing, or

related subjects.

· solid background in mathematics and numerics, strong publication

record, and extensive experience with implementation of advanced

numerical methods

· good social skills and the ability to work independently as well as

in a team

· professional ambitions and desire to help build a world-class

research team

Prior experience with modelling and simulation of flow in porous

media, reservoir simulation, or geological modelling is an advantage,

but not a requirement.

The postdoctoral researcher is expected to:

· develop, implement, and validate new numerical methods

· contribute with innovative ideas, and help the research group reach

project goals

· publish in high-quality journals and give talks at international

conferences

· initiate and maintain contact with customers and collaborating

research groups

We offer:

· a creative and social work environment

· good opportunities for scientific and career development

· competitive salary and benefits

· group pension plan and insurance

· flexible work hours

Workplace: Oslo, Norway

For further information, please contact Research Director Roger

Bjørgan <mailto:Knut-Andreas.Lie@sintef.no> (tel. +47 22 06 74 83) or

Research Scientist Jørg Aarnes <mailto:Knut-Andreas.Lie@sintef.no>

(tel. +47 22 06 77 95).

A brief and concise application with CV can be delivered online or by

e-mail to Nora.Gibb@sintef.no. Certificates and references to be

delivered only on request.

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

From: Peter Butkovic <peter.butkovic@virgin.net>

Date: Tue, 28 Aug 2007 03:45:25 -0400

**Subject: Postdoctoral Research Fellowship at Birmingham (UK)**

Applications are invited for a post-doctoral research fellow in the School

of Mathematics, University of Birmingham, to work on the EPSRC funded

project Feasibility and reachability in max-linear systems under the

supervision of the Principal Investigator, Dr P Butkovic. It is a condition

of this appointment that it starts on or before 1 March 2008 and its

duration is 33 months. The successful applicant will have completed their

first degree in either mathematics or physics and a PhD, preferably in an

area of mathematics with links to numerical linear algebra and/or discrete

optimisation. Candidates in the final stages of their PhD study will also be

considered. Starting salary is £25,134 pa. Travel allowance for conferences

will be available.

Further particulars can be seen on

http://www.vacancies.bham.ac.uk/vacancies/vacancySearch.htm

Please use reference number S43191.

The closing date for applications is 20 September 2007.

If you wish to apply for this post please use the link "Applying for a job"

in the left column at Further Particulars. Any application should contain

email addresses of referees and should be accompanied by a CV and a list of

publications.

Informal enquiries prior to formal application are encouraged; they may be

made to Dr P Butkovic (P.Butkovic@bham.ac.uk).

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

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

Date: Wed, 29 Aug 2007 09:06:40 +0100 (BST)

**Subject: Contents, Special Issue, Int J of Computer Mathematics, Vol 84 Issue 8 2007 **

Volume 84 Number 8 of IJCM containing a special issue of

"Fast iterative and preconditioning methods for linear and

non-linear systems"

is now available on the T&F web site:

http://www.informaworld.com/smpp/title~content=g781667528~db=all

Block preconditioning for saddle point systems with indefinite (1, 1) block

pp.1117¨C1129, Michele Benzi; Jia Liu

Efficient d-multigrid preconditioners for sparse-grid solution of

high-dimensional partial differential equations

pp.1131¨C1149, H. Bin Zubair; C. C. W. Leentvaar; C. W. Oosterlee

Greedy Tikhonov regularization for large linear ill-posed problems

pp.1151¨C1166, L. Reichel; H. Sadok; A. Shyshkov

Multigrid based preconditioners for the numerical solution of two-dimensional

heterogeneous problems in geophysics

pp.1167¨C1181, I. Duff; S. Gratton; X. Pinel; X. Vasseur

Multilevel algorithm for a Poisson noise removal model with

total-variation regularization

pp.1183-1198, Raymond H. Chan; Ke Chen

Preconditioning and convergence in the right norm

pp.1199-1209, Andy Wathen

A short survey on preconditioning techniques for large-scale dense

complex linear systems in electromagnetics

pp.1211-1223, Yin Wang; Jeonghwa Lee; Jun Zhang

Frobenius norm minimization and probing for preconditioning

pp.1225-1248, T. Huckle; A. Kallischko

A treecode for potentials of the form r-\lambda

pp.1249-1260, Kasthuri Srinivasan; Vivek Sarin

A short note on singular values of optimal and superoptimal

preconditioned matrices

pp.1261-126, Xiao-Qing Jin; Yi-Min Wei

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

From: Chi-Wang Shu <shu@dam.brown.edu>

Date: Mon, 27 Aug 2007 17:17:16 -0400

**Subject: Contents, Journal of Scientific Computing**

Journal of Scientific Computing

http://www.springeronline.com/journal/10915

Volume 32, Number 3, September 2007

Efficient Numerical Solution of the Density Profile Equation

in Hydrodynamics

G. Kitzhofer, O. Koch, P. Lima and E. Weinmuller, pp.411-424.

Complex Valued Spectral Hermite Approximations for the

Actively Mode-Locked Laser

Kelly Black and John B. Geddes, pp.427-448

Practical Implementation of Krylov Subspace Spectral Methods

James V. Lambers, pp.449-476.

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

From: Ron Boisvert <boisvert@nist.gov>

Date: Mon, 27 Aug 2007 11:49:54 -0400

**Subject: Contents, ACM Transactions on Mathematical Software**

Table of Contents

ACM Transactions on Mathematical Software

Volume 33, Issue 4 (August 2007)

For more information, including abstracts and access

to full text, see http://www.acm.org/toms/V33.html.

Article No. 22

TestU01: A C library for empirical testing of random number generators

Pierre L'Ecuyer, Richard Simard

40 pages

Article No. 23

hpGEM---A software framework for discontinuous Galerkin finite element

methods

Lars Pesch, Alexander Bell, Henk Sollie, Vijaya R. Ambati, Onno Bokhove,

Jaap J. W. Van Der Vegt

25 pages

Article No. 24

deal.II---A general-purpose object-oriented finite element library

W. Bangerth, R. Hartmann, G. Kanschat

27 pages

Article No. 25

A parallel symmetric block-tridiagonal divide-and-conquer algorithm

Yihua Bai, Robert C. Ward

23 pages

Article No. 26

Accurate numerical derivatives in MATLAB

L. F. Shampine

17 pages

Article No. 27

Algorithm 869: ODRPACK95: A weighted orthogonal distance regression

code with bound constraints

Jason W. Zwolak, Paul T. Boggs, Layne T. Watson

12 pages

Article No. 28

Remark on Algorithm 644

Masao Kodama

12 pages

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

End of NA Digest

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