NA Digest Sunday, February 6, 1994 Volume 94 : Issue 6

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

Submissions for NA Digest:

Mail to

Information about NA-NET:

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From: Mustapha Bouhtou <>
Date: Mon, 31 Jan 94 13:51:00 +0100
Subject: Interior Methods for Electrical Problems

Can anyone give me some references on the applications of
the recent interior point methods in the electrical area.

Please send to
Thanks in advance.
Mustapha Bouhtou
Electricite de France


From: Jan Chleboun <utam@cspgas11.bitnet>
Date: Tue, 01 Feb 94 19:33:25 EDT
Subject: Query about Interpolation of Scattered Data

Dear Members of Na-net,
My colleague is interested in computer programs (source code preferred)
and/or papers related to *local* interpolation of a bivariate function f(x,y)
given by a set of scattered data points {[x_i,y_i,z_i]: i=1,...,N}.

Any hints and suggestions are very welcome. Many thanks in advance.

Please send your responses to Mr. Jaroslav Valach
Inst. of Theor. and Appl. Mech.
Pod vodarenskou vezi 4
182 00 Prague 8
Czech Republic


From: Yuefan Deng <>
Date: Mon, 31 Jan 94 09:08:19 EST
Subject: Fast Parallel Matrix Multiplication

This mail is a response to the request for fast matrix multiplication
techniques. A paper we have recently finished seems
relevant to mention here (title and abstract are included.)
Please let me know if more information is needed.
A copy of the source code will be provided upon request.

TITLE: A Massively Parallel Method for Matrix Multiplication
Based on Strassen's Method

ABSTRACT: We present the first parallel method
for matrix multiplication on distributed-memory architectures
based on Strassen's method. Our tests, performed on an Intel Paragon,
show that our method is systematically faster
than all existing parallel methods.
The larger the matrices are, the greater is the improvement
of our method. For matrices of order $M= 5000$, our
method is about five times faster than the Ring method coupled with the
traditional method for matrix multiplication,
a typical method on distributed-memory machines.
Also, we have noticed nearly perfect speedup when the processor number is
divisible by $7$. When the processor number is not
divisible by $7$, we have also achieved a reasonable speedup.

C.-C. Chou,
Yuefan Deng {To whom correspondence should be sent), and
Y. Wang
Center for Scientific Computing
The University at Stony Brook
Stony Brook, NY 11794-3600

PS: This paper was submitted to
``SIAM Journal on Scientific Computing'' on Nov. 21, 1993.


From: Rosie Renaut <>
Date: Wed, 2 Feb 94 14:37:29 MST
Subject: Products of Fourier Transforms

I have received the following question from a graduate student in engineering.
Can anyone be of help. Please respond directly to Tim Haynes

I am interested in computing Convolution Sums using two-
dimensional FFT's and for up to quartic nonlinearities:

N/2-1 K/2-1
------ ------
u1(i,j)= \ \ u1hat(k,n)exp(i k x(i))exp(i n y(j))
/ /
------ ------
n=-N/2 k=-K/2

N/2-1 K/2-1
------ ------
u2(i,j)= \ \ u2hat(k,n)exp(i k x(i))exp(i n y(j))
/ /
------ ------
n=-N/2 k=-K/2

.....similar definitions for u3(i,j) and u4(i,j). Here
u1(i,j) is the physical quantity on the (x,y) grid and
u1hat(k,n) are the corresponding Fourier coefficients. I want
to compute the Fourier coefficients of the nonlinear term
V(i,j)=u1(i,j)*u2(i,j)*u3(i,j)*u4(i,j) given
u1hat(k,n)...u4hat(k,n). This is typically done by (1)
performing inverse FFT on the u1hat....u4hat to get u1...u4
in phyiscal space, (2) multiplying u1...u4 in physical space
to get V, (3) computing Vhat by forward FFT on V(i,j). This
method produces aliasing errors, which could be removed by
"padding" or "phase-shifting". "padding" and "phase-shifting"
require significantly more computations to remove the
aliasing errors. Is there a cheaper way to remove these
aliasing errors? I compute these nonlinear terms at each step
of an evolution problem, using 2nd-order backward
differencing for the time-like variable.


From: Allison Bogardo <>
Date: Wed, 02 Feb 94 16:30:56 EST
Subject: SIAM Student Paper Prizes

The annual SIAM Student Paper Prizes will be awarded during the 1994 SIAM
Annual Meeting.

If you are a student or know of a student who would like to take part in the
competition, here are the details:

The authors of the three best papers in applied and computational mathematics
written by students and submitted to SIAM will be invited to attend the 1994
annual meeting in San Diego, July 25-29. Each winner must present his/her
paper at the meeting and will receive a $750 cash award as well as gratis
registration for the meeting. Winners will be awarded calligraphed
certificates at a special prize ceremony at the meeting. Papers must be
singly authored and not previously published or submitted for publication to
be eligible for consideration. To qualify, authors must be students in good
standing who have not received their PhDs at the time of submission.

In submitting their work for publication, authors are asked to consider SIAM

Submissions must be received by SIAM on or before March 15, 1994.

Submissions, which must be in English, can be sent by regular mail or fax.
Each submission must include (1) an extended abstract NOT LONGER THAN 5 PAGES
(including bibliography); (2) the complete paper, which will be used solely
for clarification of any questions; (3) a statement by the student's faculty
advisor that the paper has been prepared by the author indicated and that the
author is a student in good standing; (4) a letter by the student's faculty
advisor describing and evaluating the paper's contribution; and (5) a short
biography of the student.

Submissions will be judged on originality, significance, and quality of

The winners will be notified by June 1, 1994.

If you have any questions, please contact:

Allison Bogardo
3600 University City Science Center
Philadelphia, PA 19104-2688
Telephone: (215) 382-9800
E-mail to
Fax to (215) 386-7999


From: Stanly Steinberg <>
Date: Thu, 3 Feb 94 09:47:32 MST
Subject: New Book on Grid Generation

Now available:
Fundamentals of Grid Generation
Patrick M. Knupp
Ecodynamics Research Associates
Stanly Steinberg
University of New Mexico

The book begins with a discussion of the well-known grid generation
methods for logically-rectangular grids, along with a description of
how to use the generated grids to solve steady-state (elliptic) partial
differential equations. The remainder of the book is devoted to a
discussion of variational grid generation techniques. The known
practical algorithms are described in detail, and in addition,
the reader is also brought up to date on the current research frontiers.
A large number of example grids are given and the book comes with a
floppy disk that contains program for generating grids and solving
partial differential equations.

The book is suitable as a text for a advanced undergraduate or graduate text.

CRC Press, Inc.
2000 Corporate Blvd., N.W.
Boca Raton, FL 33431 USA
ISBN: 0-8493-8987-9


From: Mary E. Brewster <>
Date: Mon, 31 Jan 1994 11:59:46 +1700
Subject: Workshop on Mathematic Problems in Industry

presented by
The Program in Applied Mathematics of the University of Colorado at Boulder
The Mathematics Department of Colorado State University
The Mathematics Department of the University of Colorado at Denver

In order to help meet the need for greater interaction between researchers
in industry and applied mathematicians from the academic community, a
workshop will be held in Boulder, Colorado during the week of May 16-20,
1994. The workshop is modelled upon successful programs which have been
held for many years at Oxford and RPI.

Applications are invited from individuals in industry and other research
establishments who would like to propose scientific problems for discussion
at the workshop. The problem may be at any stage of mathematical
formulation ranging between the two extremes: a problem which is yet to be
modelled, and one which has been completely reduced to a problem in
analysis and/or computation.

Academic participants in the workshop will include faculty and students
from Colorado Univerisities as well as representatives from other
institutions. A written report of the workshop results will be prepared by
the participants for the use of the industrial representative.

A fee of $1,000 will be charged to each industry participant bringing a
problem to the workshop. Industry representatives who do not bring a
problem, but do participate in the workshop will be charged a $250
registration fee. There is no registration fee for academic participants.

To facilitate planning for the workshop, we request that a brief one-page
description of each proposed problem be submitted by March 1, 1994 to one
of the members of the organizing committee.

Organizing Committee

Professor Mary Brewster (303) 492-0593 or
Professor Steve McCormick (303) 492-0662 or stevem@boulder.Colorado.EDU
Program in Applied Mathematics, University of Colorado at Boulder,
CB 526, University of Colorado, Boulder CO 80309-0526,
(303) 492-4668, FAX (303) 492-4066

Professor Jay Bourland jayb@MATH.ColoState.EDU
Department of Mathematics, Colorado State University, Fort Collins, CO 80523
(303) 491-6327, FAX (303) 491-2161

Professor Bill Briggs (303) 556-4809 or wbriggs@copper.Denver.Colorado.EDU
Department of Mathematics, University of Colorado at Denver, Denver, CO


From: David Halstead <>
Date: Wed, 2 Feb 94 09:58:28 -0600
Subject: SuperComputing '94


Sponsored by IEEE Computer Society and ACM SIGARCH

Supercomputing '94, the next conference in the series on high performance
computing and communications, will take place November 14-18, 1994, at the
Washington D.C. Convention Center. In addition to serving its traditional
purpose of advancing the science and application of supercomputing technology,
this conference will focus on research and education in computational science
and engineering. Particular emphasis will be given to applications in biology
and medicine, design and manufacturing, and environmental issues. The
educational activities at Supercomputing '94 will span the spectrum from K-12
through graduate school. All contributions to the conference will be evaluated
both on the basis of their technical merit and on the degree to which they
support the Supercomputing '94 purposes.


April 4, 1994: Papers
Proposals for Roundtables
Proposals for Tutorials
Proposals for Panel Sessions
August 1, 1994: Camera-ready final copy of Technical Papers
Proposals for Posters
Proposals for Research Exhibits

Further information and instructions for submitting technical papers,
education papers, roundtables, tutorials, research exhibits, posters,
and panels can be found in the full text of the Call for Participation,
available via anonymous ftp from

For more information about Supercomputing '94 you may also contact:

Supercomputing '94
Sherman Place
125 South 3rd
Ames, Iowa 50010-6793
Phone: 800-854-1677 or 515-294-0673
Fax: 515-294-0888


From: Anders Forsgren <>
Date: Wed, 2 Feb 94 21:52:27 +0100
Subject: 5th Stockholm Optimization Days


We welcome theoretical, computational and applied papers for the 5th
Stockholm Optimization Days, a two-day conference on optimization, to
be held at KTH (Royal Institute of Technology) in Stockholm, Sweden,
June 27-28, 1994. We plan to have sessions on crew and vehicle
scheduling, dual optimization methods and nonlinear programming among
other areas.

Invited speakers include:
T. Coleman, Cornell University, Ithaca, NY, USA
J. Desroisiers, HEC, Montreal, Canada
D. M. Gay, AT&T, Murray Hill, NJ, USA
P. E. Gill, UC San Diego, CA, USA
J.-L. Goffin, McGill University, Montreal, Canada
N. I. M. Gould, Rutherford Appleton Lab., Chilton, UK
D. Hearn, U. Florida, Gainesville, FL, USA
K. C. Kiwiel, Systems Research Institute, Warsaw, Poland
R. Mifflin, Washington State University, Pullman, WA, USA
W. Murray, Stanford University, CA, USA
M. L. Overton, Courant Institute, NY, USA
M. J. D. Powell, Cambridge University, UK
A. Ruszczynski, IIASA, Laxenburg, Austria
A. Sartenaer, FUNDP, Namur, Belgium
R. B. Schnabel, University of Colorado, Boulder, CO, USA
H. D. Sherali, Virginia Tech., Blacksburg, VA, USA
Ph. Toint, FUNDP, Namur, Belgium

Abstracts (maximum 200 words) should be sent by May 1 (preferably by
e-mail) to
or by mail to
Optimization Days
Division of Optimization and Systems Theory
S-100 44 Stockholm
Fax: +46 8 - 22 53 20.

Further information can be obtained from the same addresses.

The conference is financially supported by the Goran Gustafsson
Foundation and the Swedish National Board for Industrial and Technical
Development (NUTEK). Organizers are Ulf Brannlund, Anders Forsgren
(head), Per Olov Lindberg and Krister Svanberg from the Division of
Optimization and Systems Theory, Department of Mathematics, Royal
Institute of Technology (KTH).


From: Petr Prikryl <>
Date: Thu, 03 Feb 94 12:32:38 MET
Subject: Numerical Modelling in Continuum Mechanics

Theory, Algorithms, Applications
The Second Summer Conference

PRAGUE, CZECH REPUBLIC, August 22 - 25, 1994
Charles University in Prague

Chairmen: M. Feistauer, Charles University Prague
K. Kozel, Technical University Prague
R. Rannacher, University Heidelberg

Invited Plenary Speakers:
I. Babuska (USA), E. Dick (Belgium), R. Ewing (USA), R. Hoppe (FRG),
G.C. Hsiao (USA), W. Jaeger (FRG), C. Johnson (Sweden), R. Jeltsch
(Schwitzerland), U. Maas (FRG), M. Marion (France), J. Pitkaranta
(Finland), V. Rivkind (Russia), E. Suli (Great Britain), G. Warnecke
(FRG), M. Wheeler (USA), G. Wittum (FRG)


Fluid Dynamics
Porous Media Flows
Reactive Flow Problems
Structural Mechanics


The fee is 300 US$, which covers Conference Fee, Welcome Party,
accomodation in double room (4 nights) and meals (4x breakfast
and lunch)
(Possibility to pay a supplement for single room)

Accompanying persons: 150 US$

Information and Contact:
Prof. Dr. M. Feistauer
Faculty of Mathematics and Physics
Charles University Prague
Sokolovska 83
186 00 Praha 8
Czech Republic E-mail:
Fax: +42 2 23 10 464
Phone: +42 2 23 10 464

Kindly inform your colleagues interested in this field


From: Ralph B Kearfott <>
Date: Fri, 4 Feb 1994 09:42:56 -0600
Subject: Interval'94 Conference

Dear colleagues,

We are glad to inform you that preparation of the International
Conference on Interval and Computer-Algebraic Methods in Science and
Engineering - INTERVAL'94 (March 7-10, 1994, St.Petersburg, Russia) is
now in progress. The Organizing Committee has accepted more than 130
abstracts authorized by more than 160 scientists from 25 countries.

The collection of abstracts is already in the printing house, but you
still can submit a late abstract, and your talk can be included in the
program. Please, write to the e-mail address or fax
to the phone number (812) 234-4852 as soon as possible.

If your abstract has been already accepted, but you didn't receive a
formal invitation for a visa, please also write to The Organizing
Committee as soon as possible.

We are looking forward to see you in St.Petersburg!

J. Wolff von Gudenberg,
Co-chairmen of INTERVAL'94


From: Margaret Chapman <>
Date: 4 Feb 94 16:38:45 PST
Subject: Object-Oriented Numerics Conference

April 24-27, 1994
Sunriver, Oregon

This conference provides a forum where computer scientists and
scientific programmers can discuss how to use object-oriented
programming techniques to more effectively write complex scientific
codes. As numerical programs are becoming more and more complicated,
people are looking for ways to manage this complexity. Object-
oriented programming gives you the ability to write code at a higher
level of abstraction, allowing you to reduce the complexity of
numerical programs. Anyone and everyone who is currently working in
object-oriented numerics, or would like to, should not miss this

There will be approximately 38 technical presentations and a poster
session in which workers in the field will present the results of
their latest efforts in object-oriented numerics. Session topics

- Components - Modeling
- Tools/Optimization
- Design/Languages
- Components - Optimization/Linear Algebra
- Parallel - Components, Applications, and Environments

Preliminary Programs available now.

For information and registration contact:
Margaret Chapman
Program Coordinator
Rogue Wave Software
P.O. Box 2328
Corvallis, OR 97339
(503) 754-3010
FAX (503) 757-6650


From: Julie Addy <julie@TC.Cornell.EDU>
Date: Mon, 31 Jan 1994 15:50:30 -0500
Subject: Position at Cornell University

The Cornell University Theory Center invites applications for the position of
Scientific Applications Consultant. The Theory Center is supported by the
National Science Foundation, as well as other federal, state, and private sector
agencies. The Center is dedicated to providing a national focal point for using
high performance computing as a tool to accelerate the solution of scientific,
engineering, and industrial problems, while at the same time advancing the basic
and applied research that underlies that universal tool.

This individual will provide highly specialized and complex consulting and
scientific applications support to the Theory Center's national and
international scientific and research community; provide in-depth consulting
and advice to researchers in enabling scientific applications on parallel
architectures, analyzing program execution, and optimizing performance;
work closely with users in analyzing problems and developing solutions;
and investigate, resolve or refer reported problems.

The successful candidate will have the minimum of a B.S. degree in a scientific
or engineering discipline; Masters or Ph.D. degree, or equivalent combination of
education, research, and experience preferred. Minimum 4-5 years FORTRAN or
C programming experience in a scientific environment, and related experience.
Demonstrated ability to work with researchers using high performance
computing. Scientific applications, parallel programming, and UNIX experience
highly desirable. Excellent interpersonal, communication, and organizational

For consideration, send cover letter and resume to Julia Addy, Dept. NA,
Theory Center, Engineering & Theory Center Building, Cornell University,
Ithaca, NY 14853-3801. AA/EOE


From: Barry Koren <>
Date: Fri, 4 Feb 1994 11:14:34 +0100
Subject: Position at CWI, Amsterdam

At CWI, in the Department of Numerical Mathematics, a vacancy exists for
the position of junior researcher in the field of CFD.

The research subject concerns the development and application of
solution-adaptive, sparse multigrid methods for the 3D, compressible
Navier-Stokes equations. (Sparse grid methods are a new, promising
approach for efficient 3D computations.)
The research tasks are both theoretical (numerical analysis) and
practical (implementation and testing), and are carried out in
the framework of a European Communities R&D program (BRITE-EURAM
Aeronautics Program). The results are directed towards application
in some major European aerospace industries.

The candidate should hold a recent M.S. degree and be familiar with
CFD-research. The research is expected to lead to a Ph.D. degree.

The position holds for four years at a maximum. (No educational or
organizational obligations exist.)

Further information about the position can be obtained from
prof.dr. P.W. Hemker (tel: +31.205924108, e-mail:, or
dr. B. Koren (tel: +31.205924114, e-mail:

Written applications, with resume and marked with "vacancy BRITE",
can be sent to:

Personeelsdienst van de Stichting Mathematisch Centrum
Kruislaan 413
NL-1098 SJ Amsterdam
The Netherlands


From: Qasim M.Sheikh <>
Date: Wed, 2 Feb 94 11:17:59 CST
Subject: Position at Cray Research Inc

The Applications Department of CRI has an open position for a candidate
who has a Ph.d. degree in applied mathematics, computational engineering
or numerical analysis, with 0 to 5 years of practical experience.

This person will work with developers of emerging mathematical
technologies for linear and nonlinear iterative solvers. A major portion of
the job will involve working with a team of scientists that are
responsible for implementation and incorporation of iterative solvers for
linear and nonlinear systems of equations and approximation schemes
for differential and integral equations in applications software.
Additionally, the work will provide support for several of the leading
mathematical libraries vendors.

Preference will be given to persons with working knowledge of high
performance computer architectures, as related to the above activities,
and a understanding of one or more of following applications areas:
computational electro-magnetics, computational fluid dynamics, reservoir
simulation, structural analysis, etc.

Please send resumes by surface mail to:
David Caliga
Tel: 612 683 3682 Fax: 612 683 3699
Manager, Earth & Environmental Sciences Group
Cray Research, Inc
Eagan, MN 55121


From: Eduardo Sontag <>
Date: Mon, 31 Jan 94 09:02:27 EST
Subject: Contents, Control, Signals, and Systems

TABLE OF CONTENTS, Math of Control, Signals, and Systems
Volume 6, Number 1

Svatopluk Poljak and Jiri Rohn,
Checking robust nonsingularity is NP-complete, pp. 1-9.

B.D.O. Anderson and M. Deistler,
Identification of Dynamic Systems from Noisy Data: The Case m = n-1, pp.10-29.

L. Gurvits, L. Rodman, T. Shalom,
Controllability by completions of partial upper triangular matrices, pp. 30-40.

Luiz A.B. San Martin,
Invariant control sets on flag manifolds, pp. 41-61.

A. Le Breton and Dinh Tuan Pham,
Maximum Likelihood Estimation for Continuous Time Autoregressive Model by
Relaxation on Residual Variances Ratio Parameters, pp. 62-75.

Christiaan Heij,
Identification of non-controllable systems from impulse response measurements,
pp. 76-97.


From: Carlos Demoura <demoura@clapas.univ-montp2.f>
Date: Wed, 2 Feb 94 13:52:34 +0100
Subject: Contents, Matem Aplicada e Computacional

Computational and Applied Mathematics
(Matematica Aplicada e Computacional)
Edited by
SBMAC - Brazilian Soc. for Comp. and Appl. Mathematics (Rio)
Birkhauser Verlag (Boston)

Vol.12 N.2 (1993)

J.M. Martinez
On the convergence of the column-updating method
P. Gauzellino & J.E. Santos
Numerical methods for wave propagation in elastic and anelastic media
G. Aimez & P-A. Gremaud
On a penalty method for the Navier-Stokes problem in regions with
moving boundaries.
J.L. Menaldi & D.A. Tarzia
Generalized Lame-Clapeyron solution for a one-phase sourse Stefan problem
L. Nachbin
Suplattices associated with convex sets, convex cones and affine spaces
A.L. Iusem & M. Teboulle
On the convergence rate of entropic proximal optimization methods

Vol.12 N.3 (1993)

J. Baumeister & E.R.von Stockert
On a integral equation related to an inverse problem in magnetocardiography
J. Douglas Jr. & J. Wang
A new family of mixed finite element spaces over rectangles
J.M. Stern & S.A Vavasis
Active set methods for problems in column block angular form
W.C. Connet, WL Golik & A.L. Schwartz,
A superconvergent scheme on irregular grids for systems of two-point
boundary value problems


From: SIAM <>
Date: Thu, 03 Feb 94 15:36:21 EST
Subject: Contents, SIAM Control and Optimization

SIAM J. Control and Optimization
Volume 32 Number 3 May 1994


On Generalized Second-Order Derivatives and Taylor Expansions in Nonsmooth
W. L. Chan, L. R. Huang, and K. F. Ng

Optimal Control on the L Norm of a Diffusion Process
Guy Barles, Christian Daher, and Marc Romano

On the Game Riccati Equations Arising in H Control Problems
Pascal Gahinet

Adaptive Boundary and Point Control of Linear Stochastic Distributed Parameter
T. E. Duncan, B. Maslowski, and B. Pasik-Duncan

Solution of Some Transportation Problems with Relaxed or Additional Constraints
S. T. Rachev and L. Ruschendorf

The Free Boundary of the Monotone Follower
Maria B. Chiarolla and Ulrich G. Haussmann

Generalized Solutions of the Hamilton-Jacobi Equation of Stochastic Control
Ulrich G. Haussmann

On the Nonlinear Dynamics of Fast Filtering Algorithms
Christopher I. Byrnes, Anders Lindquist, and Yishao Zhou

Controlled Invariance for Singular Distributions
Viswanath Ramakrishna

Differential Games With Information Lags
Xiaojun Qian

A Dissipative Feedback Control Synthesis for Systems Arising in Fluid Dynamics
Kazufumi Ito and Sungkwon Kang

Decentralized Pole Assignment and Product Grassmannians
Xiaochang Wang

The Output-Nulling Space, Projected Dynamics, and System Decomposition for
Linear Time-Varying Singular Systems
William J. Terrell

New Existence Results for Optimal Controls in the Absence of Convexity: The
Importance of Extremality
Erik J. Balder


From: SIAM <>
Date: Thu, 03 Feb 94 15:40:15 EST
Subject: Contents, SIAM Discrete Mathematics

SIAM J. Discrete Mathematics
Volume 7 Number 2 May 1994


Indifference Digraphs: A Generalization of Indifference Graphs and Semiorders
M. Sen and B. K. Sanyal

Some New Bounds on Single-Change Covering Designs
Guo-Hui Zhang

On the Angular Resolution of Planar Graphs
Seth Malitz and Achilleas Papakostas

Planar Separators
Noga Alon, Paul Seymour, and Robin Thomas

A Stochastic Process Interpretation of Partition Identities
G. M. Constantine and T. H. Savits

The Square of a Hamiltonian Cycle
Genghua Fan and Roland Haggkvist

An O(n log n) Algorithm for Bandwidth of Interval Graphs
Alan P. Sprague

The Laplacian Spectrum of a Graph II
Robert Grone and Russell Merris

A 2d - 1 Lower Bound for Two-Layer Knock-Knee Channel Routing
Tom Leighton

The Divisors of x2m + x of Constant Derivatives and Degree 2m-2
Claude Carlet

The k-Edge-Connected Spanning Subgraph Polyhedron
Sunil Chopra

Constructing Small Sample Spaces Satisfying Given Constraints
Daphne Koller and Nimrod Megiddo

The Minimum Satisfiability Problem
Rajeev Kohli, Ramesh Krishnamurti, and Prakash Mirchandani

On Optimal Depth Threshold Circuits for Multiplication and Related Problems
Kai-Yeung Siu and Vwani P. Roychowdhury

On Finding Critical Independent and Vertex Sets
Alexander A. Ageev

Triangulating Vertex-Colored Graphs
F. R. McMorris, Tandy J. Warnow, and Thomas Wimer

Bipartite Subgraphs of Triangle-Free Graphs
Svatopluk Poljak and Zsolt Tuza

Sums of Squares of Edge Lengths and Spacefilling Curve Heuristics for the
Traveling Salesman Problem
Jun Gao and J. Michael Steele

Eulerian Self-Dual Codes
L. Babai, H. Oral, and K. T. Phelps

Clique Graphs of Chordal and Path Graphs
Jayme L. Szwarcfiter and Claudson F. Bornstein


End of NA Digest