### Today's Editor:

- Cleve Moler
- The MathWorks, Inc.
- moler@mathworks.com

- Change of Address for Cleve Moler
- New Address for Siamak Hassanzadeh
- Address Change for C. A. de Moura
- Bracewell on the Hartley Transform
- Errata for Strikwerda's Textbook
- Conference on Applications of Dynamical Systems
- Short Course on Numerical Optimization and Software
- Scalable High Performance Computing Conference
- IMA Workshop on Linear Algebra for Signal Processing
- Visiting Positions at RIACS
- Contents: Linear Algebra and its Applications

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

From: Cleve Moler <moler@mathworks.com>

Date: Sun Mar 15 06:21:03 PST 1992

**Subject: Change of Address for Cleve Moler**

For the past two and a half years, I've been commuting between my

home in California and the MathWorks main office outside Boston.

This week, I cut 2700 miles off that commute by moving to Massachusetts.

So, my business mailing address is now:

Cleve Moler

The MathWorks, Inc.

24 Prime Park Way

Natick, MA 01760

The telephone number for the MathWorks switchboard is: 508-653-1415.

(That's 508-65-pi). You can reach my office phone directly by

dialing 508-653-2452 and then keying in extension 325.

My e-mail address remains moler@mathworks.com.

Our family's new home is in Sherborn, which is just south of Natick and

Framingham and a few miles west of Wellesey. The mailing address is:

62 Russett Hill Road, Sherborn, MA 01770.

If you're in the Boston area, and would like to visit the MathWorks,

let me know -- we'd be happy to see you.

-- Cleve

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

From: Siamak Hassanzadeh <siamak@fai.fai.com>

Date: Mon, 9 Mar 92 10:04:04-1795

**Subject: New Address for Siamak Hassanzadeh**

Effective immediately my address is

Siamak Hassanzadeh

Fujitsu America, Inc.

3055 Orchard Dr.

San Jose, CA 95134-2022

Phone: 408-456-7308

email: siamak@fai.com

I will be working in the Computational Research Division of Fujitsu.

I look forward to continuing interaction with computational community.

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

From: Carlos de Moura <demoura@menusin.inria.fr>

Date: Thu, 12 Mar 92 16:49:17 GMT

**Subject: Address Change for C. A. de Moura**

For March to August 1992 I will be working with the

Group de Calcul Parallele

Laboratoire de Physique Corpusculaire

College de France

11, Place M. Berthelot

75231 Paris 05 Cedex

FRANCE

email: demoura@cdfvax.in2p3.fr

Best Regards

Carlos A de Moura

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

From: Gene Golub <golub@esat.kuleuven.ac.be>

Date: Thu, 12 Mar 92 10:59:08 GMT

**Subject: Bracewell on the Hartley Transform**

The Hartley Transform

R.N. Bracewell

(Stanford EE370 Seminar for March 12, 1992)

Spectral analysis is usually done with the aid of the Fourier transform, which

is based on ideas inherited from the time of Fourier and makes full use of the

mathematical theory of complex analysis which, to a large extent, developed in

the last century in response to the need to resolve tricky problems of

integration and convergence thrown up by exploration of Fourier's theorem. As

students, we become familiar with the algebraic manipulation of complex

quantities and equations such as V=ZI become second nature to us; it is true

that when we come to evaluate ZI four multiplies are involved. In the days of

slide rules this factor four was very noticeable and although it is less

noticeable today, still, somewhere deep inside your calculator, four

multiplies are performed whenever two complex numbers are multiplied together.

When numerical Fourier analysis is performed complex operations are required

because the Fourier spectrum of a real waveform is necessarily complex.

Conversely, when we invert the Fourier transform we must have an algorithm

that accepts complex input. Thus, in the first case (real data) a lot of

unnecessary operations are carried out on an imaginary part that is

zero-valued, while in the second case (complex input) a lot of output values

are computed which are zero (or should be, to the limits of machine

precision). These elementary observations tell us that there should be a way

of performing spectral analysis of real data that avoids the wastefulness of a

transform that must be prepared for complex input, whereas most of the time

either our data are real, or our output is real.

This transform is the Hartley transform; it represents a waveform with

N sample values by N transform values which are real (see "Assessing the

Hartley Transform," IEEE Trans ASSP, vol. 38, 2174-2176, Dec 1990 and

references provided). Of course the Hartley transform graph is not the same

as the Fourier transform graph, which means that some of our intuition is

lost. On the other hand when we graph Fourier transforms we do not always

plot both the real and imaginary parts, which are not particularly clear to

grasp and which in fact change drastically for the same waveform if one only

changes the choice of origin of time. Usually we graph the power spectrum,

which is real and does not call on us to visualize the full complex transform.

The Hartley power spectrum is the same as the Fourier power spectrum;

likewise the Hartley phase is the same as the Fourier phase (with a 45 degree

shift). Also it is easy to learn how to see the real and imaginary parts of

the Fourier transform, given the Hartley transform, if you really want them.

In summary, it seems that we will continue to retain the advantage that we get

from fluency in complex algebra by using Fourier transforms in theoretical

work but that when we talk to computers which prefer real numbers we will

shift to the Hartley transform. By computing with real numbers we gain a

factor of two in speed in the inner loops of the algorithms. This can be very

important in new programming; however, if you have canned code that runs it is

usually not advised to tamper with it.

Interesting questions have been raised about the physical significance of the

Hartley transform relative to the Fourier transform. After all, Lord Kelvin

told us that "Fourier's theorem is not only one of the most beautiful results

of modern analysis, but it may be said to furnish an indispensable instrument

in the treatment of nearly every recondite question in modern physics." If

you have the opportunity to think about the Hartley transform in advance you

might like to consider whether the Fourier transform is more fundamental

physically.

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

From: John Strikwerda <strik@cs.wisc.edu>

Date: Fri, 13 Mar 92 13:53:31 -0600

**Subject: Errata for Strikwerda's Textbook**

I have made an errata list for my textbook available

by anonymous ftp. The text is:

Finite Difference Schemes and

Partial Differential Equations

published by Wadsworth & Brooks/Cole.

The errata are on the file

pub/strik.errata.dvi

on the computer

lemon.cs.wisc.edu

John Strikwerda

strik@cs.wisc.edu

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

From: Tina Flores <flores@siam.org>

Date: Tue, 10 Mar 92 16:55:51 EST

**Subject: Conference on Applications of Dynamical Systems**

SIAM Conference on Applications of Dynamical

Systems, October 15-19, 1992, Salt Lake City, UT

The organizers for the conference are pleased to inform you

that the DEADLINE for submitting contributed abstracts has

been EXTENDED to MARCH 20, 1992. For those of you who

have not yet submitted your 100-word abstract, send it

NOW -- by e-mail to: meetings@siam.org

by fax to: 215-386-7999

or call the SIAM office at 215-382-9800 if you have any

questions. SIAM encourages electronic submission of

abstracts. To help in formatting your submission, plain TeX

or LaTeX macros are available upon request.

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

From: Tina Flores <flores@siam.org>

Date: Thu, 12 Mar 92 09:52:09 EST

**Subject: Short Course on Numerical Optimization and Software**

SIAM WORKSHOP ON NUMERICAL OPTIMIZATION

AND SOFTWARE

Date: Sunday, May 10, 1992

Location: Hyatt Regency Hotel, Chicago, Illinois

Lecturers and organizers: Jorge J. More'

Stephen J. Wright

Both lecturers are with the Mathematics and Computer Science

Division, Argonne National Laboratory, Argonne, Illinois

The course will cover four main problem areas. These are

nonlinear equations and nonlinear least squares,

unconstrained optimization, constrained optimization, and

global optimization.

Registration Fees: SIAM Non-

Member Member Student

Advance $120 $135 $55

On-Site 135 155 75

Preprints, coffee and lunch are included in the registration

fees. Attendees are advised to preregister for the short

course. On-site registration cannot be guaranteed. Preprints

of the lecture materials will be distributed upon check-in

at the SIAM registration desk.

The short course will precede the Fourth SIAM Conference on

Optimization which will be held on Monday through

Wednesday, May 11-13, 1992, Hyatt Regency Hotel, Chicago,

Illinois.

Deadline for Advance Registration: May 4, 1992

Register NOW! By phone: 215-382-9800. By FAX: 215-386-7999.

by E-mail: meetings@siam.org

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

From: Joel Saltz <jhs@icase.edu>

Date: Wed, 11 Mar 92 17:16:50 -0500

**Subject: Scalable High Performance Computing Conference**

SCALABLE HIGH PERFORMANCE COMPUTING CONFERENCE

SHPCC '92

Sponsored by

IEEE Computer Society

April 27-29, 1992

Williamsburg Hilton and

National Conference Center

Williamsburg, Virginia

ADVANCE PROGRAM

SUNDAY, April 26, 1992

Tutorials

Computational Fluid Dynamics on Parallel Machines - Algorithms and

Applications, Ramesh Agarwal, McDonnell Douglas Research Laboratories

Using Massively Parallel Supercomputers: An Applications Perspective

Horst Simon, Computer Sciences Corporation, NASA Ames Research Center

Compilers for Scalable Architectures, Ken Kennedy, Rice University

and Joel Saltz, ICASE

SUNDAY, 6:00-9:30, Registration and Reception

MONDAY

Scalability of Data Transport, Harry Jordan, Univ. of Colorado

Parallel sessions on: Applications and Performance

Parallel sessions on: Applications and Languages

Interleaved Mass Storage: Parallel Processing in Secondary and Tertiary

Memory, Randy Katz, UC-Berkely

Parallel sessions on: Algorithms and Systems Support for Languages

Parallel sessions on: Molecular Dynamics and Tools

Evening: Technical Vendor Presentations

TUESDAY

Parallel Methods and Applications for Macromolecular

Simulations, Bernard Brooks, National Institutes of Health

Parallel sessions on: Molecular Dynamics and Support for Irregular Problems

Parallel sessions on: Computational Fluid Dynamics and Systems Issues

Computational Aerodynamics with Unstructured Meshes, Dimitri Mavriplis, ICASE

Parallel sessions on: Communication and Tools

Parallel sessions on: Computational Fluid Dynamics and Compilers

Evening: Panel on Educational Issues in Parallel Computing

WEDNESDAY

Performance Animation, Dennis Gannon, Indiana Univ.

Parallel sessions on: Applications and Languages

Parallel sessions on: Applications and Performance

For a complete elecronic or hard copy of the Advance Program

including a hotel reservation card, contact emily@icase.edu.

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

From: Willard Miller <miller@imafs.ima.umn.edu>

Date: Fri, 13 Mar 92 11:11:14 CST

**Subject: IMA Workshop on Linear Algebra for Signal Processing**

IMA Workshop on

LINEAR ALGEBRA FOR SIGNAL PROCESSING

April 6 -- April 10, 1992

Organizers: A. Bojanczyk and G. Cybenko

Signal processing is making increasingly sophisticated use of linear algebra

on both theoretical and algorithmic fronts. The purpose of this workshop is

to bring signal processing engineers, computer engineers, and applied linear

algebraists together for an exchange of problems, theories and techniques.

Particular emphasis will be given to exposing broader contexts of the signal

processing problems so that the impact of algorithms and hardware will be

better understood.

The workshop will explore five areas by having a sequence of talks devoted to

the underlying signal processing problem, the algorithmic and analytic

techniques and, finally, implementation issues for each area. The five areas

are:

1) updating SVD and eigendecompositions;

2) adaptive filtering;

3) structured matrix problems;

4) wavelets and multirate signal processing;

5) linear algebra architectures (parallel/vector and other high

performance machines/designs).

Most of the workshop talks will be held in Conference Hall 3-180 on the entry

floor of the Electrical Engineering/Computer Science Building. This building

is located on the corner of Washington Avenue and Union Street, a block from

the IMA Main Office. The conference hall is on the Ethernet and has a

projection system for display of computer output.

TENTATIVE SCHEDULE

Monday, April 6

Gene Golub, Stanford/IMA

The canonical correlations of matrix pairs and their numerical computation

Franklin T. Luk, Rensselaer Polytechnic University

Adaptive parameter estimation in signal processing

J. Cadzow, Vanderbilt University

Marc Moonen, Katholieke U. Leuven

Systolic algorithms for adaptive signal processing

Wenyuan Xu, University of Minnesota

New ideas in the design of signal-subspace detectors and estimators

Robert J. Plemmons, Wake Forest University/IMA

Preconditioned iterative least squares FIR system identification

Tuesday, April 7

Gilbert Strang, MIT

Wavelet transforms versus Fourier transforms

A. H. Tewfik, University of Minnesota

Wavelets in signal and image processing

Martin Vetterli, Columbia University

Wavelets, filter banks, and applications in compression

Jo Ward, Murdoch University

Stability of DARMA filters on spaces

M. Stewart, University of Illinois

A general linear algebraic framework for perfect reconstruction filters

Lothar Reichel, Kent State University

Wednesday, April 8

Simon Haykin, McMaster University

Fast implementation of the RLS algorithm

A. Steinhardt, Cornell University

Adaptive detection using sensor arrays

John Proakis, Northeastern University

Blind equalization

Thursday, April 9

Pierre Comon, Thomson Sintra, France

Looking for fast algorithms solving structured linear systems

Tom Kailath Stanford University

Israel Koltracht, University of Connecticut

Structured condition numbers

Georg Heinig, Universitaet Leipzig/IMA

Fast algorithms for generalized Cauchy matrices and rational interpolation

Gregory Ammar, Northern Illinois University

Updating and downdating Szego polynomials

Friday, April 10

Robert Schreiber, NASA Ames Research Center/IMA

Matrix computation on SIMD data-parallel architectures

E. Deprettere

INSTITUTE FOR MATHEMATICS AND ITS APPLICATIONS

University of Minnesota

514 Vincent Hall

206 Church Street S.E.

Minneapolis, Minnesota 55455

FAX (612) 626-7370 telephone (612) 624-6066

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

From: Joseph Oliger <oliger@riacs.edu>

Date: Fri, 13 Mar 92 14:34:51 PST

**Subject: Visiting Positions at RIACS**

RESEARCH INSTITUTE FOR ADVANCED COMPUTER SCIENCE

NASA Ames Research Center

Moffett Field, CA

The Research Institute for Advanced Computer Science (RIACS) at the

NASA Ames Research Center, located in the San Francisco Bay Area

adjacent to Silicon Valley, is inviting applications for visiting

research positions for graduate students for the summer of '92 and for

post-doctoral appointments of up to two years begining in the Fall of '92.

RIACS carries out a basic research program in the computational

sciences to support the needs of NASA Ames scientific missions.

Specific areas of interest are: algorithms and software for parallel

scientific computation with applications to computational fluid

dynamics, adaptive and composite mesh methods for solving partial

differential equations, the design and implementation of compilers and

tools for parallel computers, and the analysis of high performance

networks.

The computing environment at NASA Ames Research Center includes a

Connection Machine (CM-2), an Intel iPSC/860, a Cray Y-MP and a

Cray-2. High performance graphics workstations are also available.

Visitors to RIACS are expected to collaborate with NASA Ames scientists.

Additional opportunities for collaboration abound with the many local

research universities and institutions.

Applicants should send resumes and descriptions of research interests

with references to:

Joseph Oliger, Director

RIACS

NASA Ames Research Center

Mail Stop T041-5

Moffett Field, CA 94035-1000

Applications and inquiries may also be made via e-mail to:

oliger@riacs.edu

RIACS is an Equal Opportunity Employer.

(PLEASE POST)

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

From: Richard A. Brualdi <brualdi@imafs.ima.umn.edu>

Date: Tue, 10 Mar 92 16:37:35 CST

**Subject: Contents: Linear Algebra and its Applications**

Contents of LAA Volume 167, April 1, 1992

Preface 1

Daniel Hershkowitz (Haifa, Israel)

The Height Characteristic of Block Triangular Matrices 3

Naomi Shaked-Monderer and Abraham Berman (Haifa, Israel)

More on Extremal Positive Semidefinite Doubly Stochastic Matrices 17

Pal Rozsa (Budapest, Hungary) and Francesco Romani (Pisa, Italy)

On Periodic Block-Tridiagonal Matrices 35

S. W. Hadley (Waterloo, Canada), F. Rendl (Graz, Austria), and H. Wolkowicz

(Waterloo, Canada)

Symmetrization of Nonsymmetric Quadratic Assignment Problems and the

Hoffman-Wielandt Inequality 53

Bit-Shun Tam (Tamsui, Taiwan)

On the Structure of the Cone of Positive Operators 65

Adi Ben-Israel (New Brunswick, New Jersey)

A Volume Associated With mxn Matrices 87

Mark Krupnik (Haifa, Israel)

Changing the Spectrum of an Operator by Perturbation 113

Michael Gorodetsky (Haifa, Israel)

Inversion of Quasitriangular Block Toeplitz Matrices 119

J. C. Willems (Groningen, The Netherlands) and P. A. Fuhrmann (Beer Sheva,

Israel)

Stability Theory for High Order Equations 131

Moshe Roitman and Zalman Rubinstein (Haifa, Israel)

On Linear Recursions With Nonnegative Coefficients 151

Yoav Yaacoby and Peter R. Cappello (Santa Barbara, California)

Decoupling the Dimensions of a System of Affine Recurrence Equations 157

Avram Sidi (Haifa, Israel)

Development of Iterative Techniques and Extrapolation Methods for Drazin

Inverse Solution of Consistent or Inconsistent Singular Linear Systems 171

Abraham Berman, Moshe Goldberg, and Daniel Hershkowitz (Haifa, Israel)

REPORT: Haifa 1990 Conference on Matrix Theory 205

Author Index 273

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

End of NA Digest

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