NA Digest Sunday, September 25, 1988 Volume 88 : Issue 38

Today's Editor: Cleve Moler

Today's Topics:


From: Apostolos Gerasoulis <>
Date: Sun, 18 Sep 88 13:35:45 EDT
Subject: Fourth Parallel Circus


RUTGERS University, New Brunswick, New Jersey, December 2-3, 1988

THEME: Parallel Numerical Algorithms, Programming Tools and Applications.

OBJECTIVE: The meeting is an informal gathering of researchers
interested in parallel processing. The intention is to discuss recent
results in the area and exchange ideas for future work. The atmosphere
is completely casual and the speakers are chosen at the beginning of
the circus. To encourage easy discussion, there are no formal
proceedings. We hope that about 50 persons will be in attendance and
there are no parallel sessions.

HISTORY: It has been customary for the circus to be held twice a year
during Friday and Saturday. The first Parallel Circus was held in May
1987 at Yale (Chaired by Prof. M. Schultz), the second at Cornell in
November 1987, (chaired by Prof. Van Loan), and the third at IBM
Kingston (organized by V. Sonnad and chaired by Prof. G. Golub and M.

PLACE: The Fourth Parallel Circus is organized by Rutgers University
and will be held at the Hyatt Regency Hotel at New Brunswick, New
Jersey (chaired by G. Golub and A. Gerasoulis). New Brunswick is
located between New York (35 miles southwest) and Philadelphia and is
easily accessible via plane (Newark airport), train and automobile.

CONTACTS: If you wish to attend please contact Prof. Apostolos
Gerasoulis or Ms. Priscilla Rasmussen as soon as possible. PHONE:
(201)-932-2725/2768, E-MAIL:,, ADDRESS: Department of Computer Science,
Rutgers University, New Brunswick, NJ 08903. If you wish to present
your work at the meeting include the title of your talk in your

DEADLINES: The reservation cut off date for the conference rate at the
Hyatt is 11/10/88.


From: Rolf Jeltsch <JELTSCH%DACTH51.BITNET@Forsythe.Stanford.EDU>
Date: Mon, 19 Sep 88 10:51:21 CET
Subject: Factoring Polynomials

A collegue of mine, Prof. Plesken has asked me whether numerical
analysts know the following algorithm to compute
factors of polynomials. I would like to present this
question to the NA community. If you see resemblence to known
algorithms or even have a reference please let me know or wirte
directly to my collegue: His e-mail address is
Here comes the description of the algorithm.
Assumption: x is an indeterminate and f(x)=x~n+a_(n-1)x~(n-1)+...+a_0
in R[x] is a real polynomial.
Aim: Find a factorization f(x) = g(x)h(x).
Framework: R[x]/f(x) denotes the ring of polynomials modulo f(x), whose
elements are represented by the polynomials p(x) of degree less than n.
The relation x~n=-(a_0+...+a_(n-1)x~(n-1)) is used to find this normal
form e(p(x)) for p(x) in R[x] of degree greater or equal to n. Note,
multiplication by x is represented by the companion matrix A of f(x)
with respect to the basis 1,x,...,x~(n-1) of R[x]/f(x) and multiplication
by p(x) by p(A)=:mat(p(x)).
Algorithm:Choose a_0=p(x) in R[x]/f(x) with norm 1(= det(p(A))). Define
a_(i+1):=a_i~2 ( multiplication in R[x]/f(x)). For moderately large n
mat(a_n) will have k>0 eigenvalues close to zero and n-k>0 eigenvalues
very big.(We neglect the case where p(A) has eigenvalues of absolute
value 1.) Let z:=a_n. Test when z,xz,x~2z,... becomes (approximately)
linearly dependent in R[x]/f(x) for the first time and obtain a relation
x~kz=c_0z+c_1xz+...+c_(k-1)x~(k-1)z. Then g(x)=x~k-c_(k-1)x~(k-1)-...-c_0
in R[x] is a polynomial dividing f(x). Varying the degree of accuracy
one might find different k's and divisors g(x) also with varying degree
of accuracy from the same element z.
--Rolf Jeltsch


From: UNCJWT%UNC.BITNET@Forsythe.Stanford.EDU
Date: Mon, 19 Sep 88 16:40 EST
Subject: Position in North Carolina



The Department of Mathematics at the University of North Carolina
invites applications for a senior level tenured appointment in the
general area of applied and/or computational mathematics. Rank and
salary depend on qualifications; demonstrated excellence in research
and teaching are required. Applications will be accepted until the
position is filled; however, applications received by January 15,1989
are assured of full consideration. Inquiries should be directed to:
Search Committee, % Pat Levin, Mathematics Department, CB# 3250,
UNC at Chapel Hill, Chapel Hill, NC 27599. EO/AA employer. Women
and minorities are encouraged to apply.


From: Alan J. Laub <>
Date: Wed, 21 Sep 88 14:42:13 PDT
Subject: Riccati Equation Meeting in Italy



sponsored by
C.N.R. -- Consiglio Nazionale delle Ricerche

co-sponsored by
I.F.A.C. -- International Federation of Automatic Control
S.I.A.M. -- Society for Industrial and Applied Mathematics

with the participation of the
I.E.E.E. Control Systems Society

Politecnico di Milano
Dipartimento di Elettronica
Centro di Teoria dei Sistemi C.N.R.


To present a coherent picture of the main results achieved in the
last 30 years on the Riccati Equation. Theory, applications, and
numerical algorithms will be considered with emphasis on its
relevance to optimal control and filtering, Linear-Quadratic-
Gaussian problems, H-infinity optimization, network synthesis,
etc. There will be an opening lecture by R.E. Kalman -- Swiss
Federal Institute of Technology, Zurich, Switzerland and Univer-
sity of Florida, USA, three tutorial lectures (by A.J. Laub --
University of California, Santa Barbara, USA, M.A. Shayman --
University of Maryland, USA, and J.C. Willems -- University of
Groningen, The Netherlands), invited lectures, and contributed
The language of the meeting is English.


S. Bittanti -- Politecnico di Milano, Italy
A.J. Laub -- University of California, Santa Barbara, U.S.A.
J.C. Willems -- Groningen University, The Netherlands
H.H. Wimmer -- Universitat Wurzburg, West Germany


R.R. Bitmead -- Australian National University, Australia
S. Bittanti -- Politecnico di Milano, Italy
R.S. Bucy -- University of Southern California, USA
R. Byers -- University of Kansas, USA
A. Bunse-Gerstner -- Universitat Bielefeld, West Germany
M. Gevers -- Universite Catholique Louvain, Belgium
K. Glover -- Cambridge University, UK
D. Hinrichsen -- Universitat Bremen, West Germany
T. Kailath -- Stanford University, USA
V. Kucera -- Czechoslovak Academy of Science, Czechoslovakia
V. Mehrmann -- Universitat Bielefeld, West Germany
J.B. Moore -- Australian National University, Australia
T. Nishimura -- Institute of Space and Astronautical Science, Japan
L. Rodman -- College of William and Mary, USA
L.M. Silverman -- University of Southern California, USA
J.L. Speyer -- University of Texas at Austin, USA
H.L. Trentelman -- Technische Universiteit Eindhoven, The Netherlands
J.L. Willems -- University of Ghent, Belgium
H.H. Wimmer -- Universitat Wurzburg, West Germany


There is time allotted for high quality contributed papers. Only
papers with original results will be accepted. Prospective au-
thors are invited to submit 5 copies of an extended summary or
draft manuscript in English to the Chairman at the following ad-
Professor S. Bittanti
Dipartimento di Elettronica
Politecnico di Milano
Piazza Leonardo da Vinci 32
20133 Milano
Telefax 2.23993587 Telex 333467 POLIMI-I

The length of the draft should be approximately 5 double-spaced
pages. Authors should also provide a title page, with a 350-word
abstract, 5 keywords, full address, telephone or telefax number,
and e-mail address if available.


November 30, 1988 5 copies of a 5 page extended summary or draft
plus a title page to be mailed to the chairman

February 28, 1989 Acceptance notification for contributed drafts

April 30, 1989 Full manuscript due


The meeting will be held at Villa Gallia, an 18th Century villa
located on the shore of Lake Como in Como, Italy. The historic
town of Como is easily reachable from Milan either by car (motor-
way A9) or train. Frequent trains start from Stazione Ferrovie
Nord in Milan, but there are trains from the Stazione Centrale or
Stazione Porta Garibaldi as well. Alternatively, Como can be
reached from the Zurich airport by train or by car.


S. Bittanti -- Politecnico di Milano, Italy
P. Bolzern -- Politecnico di Milano, Italy
P. Colaneri -- Centro di Teoria dei Sistemi C.N.R., Italy
C. De Nicolao -- Centro di Teoria dei Sistemi C.N.R., Italy

In organizing the workshop, the organizers are being assisted by
the Centro di Cultura Scientifica A. Volta, Villa Olmo (Como).
The assistance of the Centro di Teoria dei Sistemi C.N.R., Mi-
lano, and the Dipartimento di Elettronica del Politecnico di Mi-
lano is also gratefully acknowledged.


The Centro di Cultura Scientifica A. Volta will take care of the
local organization, including hotel reservations. An early
reservation is recommended since Como is already crowded with
tourists in June. The address of the Centro is:
Centro di Cultura Scientifica A. Volta
Villa Olmo
Via Cantoni 1
22100 Como

Phone number: 31.552563 or 31.572213
Telex: 380547 CAM CO I


From: Baker Kearfott <>
Date: Thu, 22 Sep 88 09:03:34 CDT
Subject: Nineteenth Annual USL Mathematics Conference

OCTOBER 21 - 23, 1988

This year's weekend conference will be devoted to
analysis (classical, applied, and numerical). We expect to
follow the format of previous years, with colloquium type
talks beginning Friday afternoon and ending early Sunday
afternoon. We will also be inviting everyone to dinner
Friday evening and to the shrimp boil on Saturday evening.

A partial list of speakers is:

John Cannon (Office of Naval Research)
John Dennis (Rice University)
Bill Fitzgibbon (University of Houston)
Robin Forman (Rice University)
Jerry Goldstein (Tulane University)
Hans Kaper (Argonne National Labs.)
Chen-Yuen Lin (Texas A&M University)
Caruth McGehee (Louisiana State University)
Jeff Morgan (Texas A&M University)
John Polking (Rice University)
Gizele Rieder (Louisiana State University)
Ralph Saxton (University of New Orleans)
Phil Smith (IMSL)
Henry Warchall (University of North Texas)
John Wolfson (Tulane University)

You are welcome (RSVP). (However, there is no support other
than for the two dinners.) For information, for comments or
suggestions, or if you wish to make a presentation, please

Baker Kearfott (318) 231-5270 (Office)
(318) 981-9744 (Home) (EMAIL)


Lloyd Roeling (318) 231-6545 (Office)
(318) 988-0148 (Home)

Mathematics Department (318) 231-6702
U. S. L. Box 4-1010
Lafayette, LA 70504


Date: Thu, 22 Sep 88 10:31:47
Subject: Dundee Biennial NA Conference 1989


27-30 June 1989

Principal Speakers include

M J Baines P Deuflhard T Lyche
J H Bramble R Fletcher M J D Powell
K Burrage I Graham A Ruhe
T Coleman C Johnson

A limited number of submitted papers will be presented. Full details
of submission dates, conference fees, etc. will be available towards
the end of 1988 and may be obtained by writing to either
Dr D F Griffiths or Dr G A Watson:
The Organizing Secretaries
Biennial Conference on Numerical Analysis
Department of Mathematics and Computer Science
The University
Dundee, DD1 4HN
Scotland, UK
Tel: 0382 23181 ext 4467/4474



From: Gene Golub <>
Date: Fri, 23 Sep 88 15:50:43 PDT
Subject: Position in OR at Stanford

Department of Operations Research

The Department of Operations Research expects to have a tenure-track
position, possibly joint with the Department of Computer Science,
to be filled by September 1, 1989. We are soliciting applications
from candidates in the areas of combinatorial optimization and numerical
optimization. Candidates must have outstandinng research ability and
potential. They must also be committed to excellence in teaching.

The position requires the individual to teach on both the graduate and
undergraduate levels, to carry out an active research program, and to
provide research supervision for Ph.D. students. Candidates at both
the junior and senior levels will be considered, although we have a
preference for a younger scholar. Stanford is an equal opportunity/
affirmative action employer. Applications from women and minorities
are especially welcome.

Candidates should send a vita, the names of at least four references,
and copies of selected publications (if any) to Prof. Donald L.
Iglehart, Department of Operations Research, Terman Engineering
Center, Stanford University, Stanford, CA 94305-4022. Further
enquiries should be made to Professor Iglehart at 415/723-4094 or


End of NA Digest