Subject: NA Digest, V. 93, # 14 NA Digest Sunday, April 4, 1993 Volume 93 : Issue 14 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: John A. Gregory Ricardo Nochetto Receives Sacchi Landriani Prize High Index DAEs Parallel L D**-1 U versus L (D**(-1),U) LAPACK, Version 1.1, New Routines Problems with "High Quality" Random Number Generators CUTE on PC's LSNNO is Now Available Very Fast Simulated Reannealing (VFSR) on Netlib Call for Papers Computer Design: A New Grand Challenge Workshop on Constrained Approximation and Optimization AWM WORKSHOP before SIAM meeting Southern Ontario NA Day Lectureships at University of Durham Contents, Linear Algebra and its Applications Contents, Numerical Algorithms Submissions for NA Digest: Mail to na.digest@na-net.ornl.gov. Information about NA-NET: Mail to na.help@na-net.ornl.gov. ------------------------------------------------------- From: Samir Matar Date: Wed, 31 Mar 93 15:59:27 BST Subject: John A. Gregory John A. Gregory Numerical Analysts everywhere will be shocked and saddened to learn of the sudden death on Friday 26 March 1993 of Dr. John A. Gregory. John had just returned from jogging when he collapsed and died of a heart attack. John had been a successful teacher for 23 years at Brunel University where he was a Reader. His research interests included approximation theory and CAGD. He supervised many successful Ph.D. students and postdoctoral Research Fellows in these fields. He will be missed at Brunel University. The wider numerical analysis community has lost a talented and dedicated scientist. All E-mail letters of condolence to John's wife, Pat, c/o the writer(samir.matar@brunel.ac.uk), will be forward to her. E.H. Twizell, S.A. Matar Mike K Warby Dept. of Maths & Stats Brunel University Uxbridge, Middx., UB8 3PH, U.K. ------------------------------ From: F. Brezzi Date: Thu, 01 Apr 93 12:38:06 ITA Subject: Ricardo Nochetto Receives Sacchi Landriani Prize On March 11, 1993 the Istituto Lombardo, Accademia di Scienze e Lettere awarded the International Giovanni Sacchi Landriani Prize for 1993 to Professor Ricardo H. Nochetto of the Department of Mathematics of the University of Maryland, College Park. The prize recognizes outstanding contributions to the field of numerical methods for partial differential equations made during the preceeding five years and carries a monetary award of ten million Italian lire. Professor Nochetto was selected by a distinguished jury from among fifteen candidates of the highest international caliber. The jury cited his results in several areas of partial differential equations and numerical analysis, giving particular emphasis to his work on free boundary problems, problems involving change of phase, and maximum norm estimates. Luigi Amerio, President of the Istituto Lombardo, conferred the award on Nochetto during the inauguration ceremonies for the 190th academic year of the institute held in the Palazzo Brera in Milan. The biennial prize was established by family, friends, and colleagues of Giovanni Sacchi Landriani, a brilliant numerical analyst who died tragically in 1989 at the age of 31. Nochetto is the second recipient of the prize, the first having been awarded to Professor Douglas N. Arnold of the Pennsylvania State University in 1991. ------------------------------ From: Steve Campbell Date: Fri, 2 Apr 1993 12:46:08 +1100 Subject: High Index DAEs High Index DAEs I am in the process of compiling a survey of linear or nonlinear differential algebraic equations (DAEs) (also known as singular, descriptor, or semi-state systems) of index four or higher which occur in applications. One way that these systems occur is in path or other constrained control problems where the relative degree is three or higher. I would be interested in any papers, preprints, or reports dealing with DAEs which are index four or higher. Both general discussions and specific models are being sought. Hardcopy or email can be sent directly to the addresses below. The report will hopefully be ready for public distribution by sometime this summer. However, information on this topic is always welcome. Incidently, most of the high index applications found so far have had index five or six, although I think I have found one index ten problem. Thank you for your assistance. Steve Campbell Department of Mathematics Box 8205 North Carolina State University Raleigh, NC 27695-8205 USA Phone: 1-919-515-3300 FAX: 1-919-515-3798 email: slc@math.ncsu.edu (Fastest) or: na.scampbell@na-net.ornl.gov or: s_campbell@ncsu.edu ------------------------------ From: Rob Schreiber Date: Mon, 29 Mar 93 09:50:16 PST Subject: Parallel L D**-1 U versus L (D**(-1),U) Ned Anderson points out that it speeds up backsolves if you store the reciprocals of the diagonal elements of the upper triangular factor U in the LU decomposition. This replaces N divides in the backsolve with N multiplies, which are usually faster. The tridiagonal LU decomposition and backsolve loops go like this: D( 1 ) = ONE / D( 1 ) DO K = 1, N - 1 MULT = DL( K ) * D( K ) D( K+1 ) = D( K+1 ) - MULT*DU( K ) B( K+1 ) = B( K+1 ) - MULT*B( K ) D( K+1 ) = ONE / D( K+1 ) END DO * D**(-1),U and (L**(-1))B calculations complete. * * Back solve: B( N ) = B( N ) * D( N ) DO K = N - 1, 1, -1 B( K ) = ( B( K )-DU( K )*B( K+1 ) ) * D( K ) END DO Since some new RISCs cannot divide worth a damn, this has real value, especially if you have to do a lot of backsolves. On really parallel machines, there is something else badly wrong with backsolve, for full matrices, that Anderson's variant doesn't address. Here is full backsolve, using this form of storage for U, annotated to point out the parallelism: * Back solve: DO K = N, 1, -1 * This statement is a sequential bottleneck B( K ) = B( K ) * U( K, K ) * This loop is a parallel DAXPY DO I = 1, K-1 B( I ) = B( I ) - U( I, K ) * B( K ) END DO END DO Assume we have N processors. The DAXPYs take (roughly) unit time, and the multiplications take unit time, so we finish in time 2N. If instead we store an LDU factorization, with unit triangular L and U, and also store D**(-1) rather than D, the sequential multiplies and divides are completely removed from the backsolve. Now, full backsolve becomes * D**(-1) B via parallel vector multiply DO K = 1, N B( K ) = B( K ) * U( K, K ) END DO * Back solve: DO K = N, 1, -1 * This loop is a parallel DAXPY DO I = 1, K-1 B( I ) = B( I ) - U( I, K ) * B( K ) END DO END DO Now, with N processors, we finish in time N, better by a factor of two. How stable? Using Matlab, I tried this on the upper triangular factors of 100 matrices generated with rand(100,100). I measured the infinity-norm of the residual (of the upper triangular system) with a random right-hand side. The L D U residuals were 60 percent larger, on average. Rob ------------------------------ From: LAPACKERS Date: Fri, 2 Apr 93 12:12:10 -0500 Subject: LAPACK, Version 1.1, New Routines Revisions Since the First Public Release of LAPACK Since its first public release in February, 1992, LAPACK has had three updates -- two minor updates and one major update. Minor updates consist of code and documentation corrections, whereas major updates introduce new routines as well as corrections. The two minor updates that occurred were on June 30, 1992 and October 31, 1992, referenced as version 1.0a and version 1.0b, respectively. The major update was denoted by version 1.1 and occurred on March 31, 1993. All LAPACK routines reflect the current version number with the date on the routine indicating when it was last modified. For more information on the revisions detailed below please refer to the LAPACK release_notes file on netlib. Minor updates will be eliminated as they were only needed to catch the inevitable flux of bug fixes that accompany any initial release. We plan to have only one or two updates a year, and provide a PRERELEASE directory on netlib to contain new software that is being considered for inclusion. Users can then provide input and experimentation with these prerelease routines. At the time of each update, there is a tar file available via xnetlib that contains all revisions for the update. You can then simply tar this file on top of your existing LAPACK directory. The entire package available in lapack.tar.z will always be the most up-to-date and include all revisions. Bug Fixes and Code Modifications: CHEGST, CHSEQR, SSTEBZ (and their double precision equivalents) had errors corrected; CLANST --> CLANHT name change to avoid notation confusion; Special version of ILAENV was missing from the TESTING and TIMING directories; All -EVX drivers and xGESVX had incorrect workspace requirements (WORK for the real routines, and RWORK in the complex routines) specified in their Argument sections; xGTCON also had incorrect workspace requirements specified in its Argument section; Added functionality has been incorporated into the expert driver routines that involve equilibration (xGESVX, xGBSVX, xPOSVX, xPPSVX, xPBSVX). The option FACT = 'F' now permits the user to input a prefactored, pre-equilibrated matrix. The testing routines in TESTING/LIN that involve these routines have also been modified; LIN Timing Suite modifications to allow the input of the number of right hand sides, and timing code added to time the GT and PT routines including comparisons with LINPACK; xGESVD bug fix and added functionality; Comments added to SLAEBZ and SSTEBZ to enforce SCALAR mode in certain loops; in addition, in front of each such "DO" statement a series of compiler directives has been added which should enforce SCALAR mode on most popular vector computers; STIM21, code correction to fix variable ITCNT in COMMON misdeclared as INTEGER instead of REAL. New Routines: xGEGS and xGEGV, driver routines for the Generalized Nonsymmetric Eigenvalue Problem with accompanying computational and auxiliary routines xGGBAK, xGGBAL, xGGHRD, xHGEQZ, xTGEVC, and SLAG2; xGGQRF and xGGRQF, computational routines for the generalized QR and RQ factorizations; xGGSVD, driver routine for the generalized singular value decomposition with accompanying computational and auxiliary routines xGGSVP, xTGSJA, xLAGS2, xLAPLL, and xLAPMT; xGGGLM, driver routine for the solution of the generalized linear regression model; xGGLSE, driver routine for the solution of the constrained linear least squares problem. Additional Features: On-line manpages (troff files) for LAPACK driver and computational routines, as well as most of the BLAS routines, available via xnetlib. As always, all questions/comments should be sent to lapack@cs.utk.edu. Regards, THE LAPACKERS ------------------------------ From: Dean Schulze Date: 03 Apr 1993 13:04:37 -0700 (MST) Subject: Problems with "High Quality" Random Number Generators A recent Physical Review Letter [1] points out that serious problems can arise in Monte Carlo computations due to subtle correlations in "high quality" random number generators. The quality of these number generators was determined to be "good" because they passed a battery of tests for randomness. However, they produced erroneous results when used together with the Wolff algorithm for cluster-flipping in a simulation of a 2 dimensional Ising model for which the results are known. The author of this Letter, Alan M. Ferrenburg of the University of Georgia, says that an algorithm must be tested together with the random number generator being used regardless of which tests the random number generator has passed on its own. In another development, Shu Tezuka of IBM, Tokyo and Pierre L'Ecuyer of the University of Montreal have proven that the Marsaglia-Zaman random number generators are "essentially equivalent" to linear congruential methods [2]. (Linear congruential number generators produced better results in Ferrenburg's simulations than random number generation algorithms that are of higher quality, however.) [1] Alan M. Ferrenburg, D.P. Landau, and Y. Joanna Wong, "Monte Carlo simulations: Hidden errors from 'good' random number generators", Phys. Rev. Lett., 69, pp. 3382-4, 1992. [2] Science News, v142, pg. 422, 1992. ------------------------------ From: Kristjan Jonasson Date: Tue, 30 Mar 93 16:31:55 CET Subject: CUTE on PC's I have now installed CUTE (Constrained and Unconstrained Testing Environment, see NA-Digest #11 1993) on an IBM PC compatible under Salford Fortran 77. Anyone interested may obtain the installation .bat-files (scripts) from me (for the time being). Kristjan Jonasson Institute for Numerical Analysis Technical University of Denmark ------------------------------ From: Philippe Toint Date: Mon, 29 Mar 93 14:33:39 +0200 Subject: LSNNO is Now Available LSNNO is now available LSNNO (Large Scale Nonlinear Network Optimization) is a set of Fortran subroutines, whose purpose is to solve optimization problems whose objective function is nonlinear (possibly nonconvex) and whose constraints represent linear flow conservation in a network. LSNNO was written by D. Tuyttens (FUNDP, Namur, Belgium). It provides a variety of algorithmic strategies to handle derivative information, including several approximation schemes. A full description of the package and a discussion of its performances can be found in Ph. L. Toint and D. Tuyttens, "LSNNO: a Fortran subroutine for solving large-scale nonlinear network optimization problems", ACM Transcations on Mathematical Software, vol. 18(3), pp. 308-328, 1992. LSNNO is written in standard ANSI Fortran 77. It uses double precision arithemetic. A fully detailed User's Guide is included as a LaTeX file in the software distribution. The package may be obtained in one of two ways. Firstly, the reader can obtain LSNNO electronically (and free of charge) via an anonymous ftp call to the account thales.math.fundp.ac.be (Internet number 138.48.4.14, in the directory lsnno) at Facultes Universitaires Notre-Dame de la Paix (Namur). We request that the userid is given as the password. This will serve to identify those who have obtained a copy via ftp. Secondly, the package can be obtained on a floppy disk or magnetic cartridge at a minimal price, intended to recoup the costs of media, packaging, preparation and courier delivery. Potentially interested parties should contact Ph. Toint for obtaining a suitable order form. It is also intended that LSNNO will be available via NETLIB soon. Ph. L. Toint pht@math.fundp.ac.be D. Tuyttens daniel@pip.umh.ac.be ------------------------------ From: Lester Ingber Date: Sun, 4 Apr 1993 13:28:57 -0700 Subject: Very Fast Simulated Reannealing (VFSR) on Netlib Very Fast Simulated Reannealing (VFSR) Netlib & Statlib updates To get on or off blind-copy VFSR e-mailings, just send an e-mail to ingber@alumni.caltech.edu with your request. VFSR is a robust algorithm for nonlinear optimization. Major changes since it was made publicly available under the GNU Copyleft in Nov 92 include support for independent setting of scales of annealing of parameters, extended documentation, and a new option novel to optimization algorithms permitting VFSR to recursively optimize its own Program Options for a given system. The unique latter capability required a major rewriting of the code to pass only local pointer-parameters in the vfsr module. It should be noted that some people have generally criticized simulated annealing algorithms as _not_ containing enough free parameters to tune different complex systems. While VFSR has demonstrated that it is surprisingly robust given its default parameters, it also is capable of quite a bit of "tuning"; I put these parameters outside the code, in a separate structure, to enable people so motivated to be able to tune their optimizations of their systems. Codes in Netlib and Statlib have been updated, replacing version 6.38. NETLIB (compressed share file) version 9.3 Interactive: ftp research.att.com [login as netlib, your_login_name as password] cd opt binary get vfsr.Z Email: mail netlib@research.att.com [AT&T Bell Labs, NJ, USA] mail netlib@ornl.gov [Oak Ridge Natl Lab, TN, USA] mail netlib@unix.hensa.ac.uk [U Kent, UK] mail netlib@nac.no [Oslo, Norway] mail netlib@cs.uow.edu.au [U Wollongong, NSW, Australia] and send the one-line message send vfsr from opt (It may take a week or so for the code in research.att.com to propagate to the other netlib sites.) STATLIB (uncompressed share file) version 9.3 Interactive: ftp lib.stat.cmu.edu [login as statlib, your_login_name as password] cd general get vfsr Email: mail statlib@lib.stat.cmu.edu and send the one-line message send vfsr from general (It may take a few days for the new version to be installed here.) After getting the file, on your local machine: ingber% uncompress vfsr.Z [If a compressed file was obtained] ingber% sh vfsr ingber% cd VFSR.DIR The directory VFSR.DIR contains the code. If you do not have ftp access, get information on the FTPmail service by sending the word "help" as a message to ftpmail@decwrl.dec.com. If you receive VFSR via e-mail, then first `uudecode mailfile', (where mailfile may be a synthesis of several files) to get vfsr.Z, and then follow the previous directions. If this is not convenient, and if your mailer can handle large files, I directly can send you the code or papers you require via e-mail. Sorry, I cannot assume the task of mailing out hardcopies of code or papers. Lester || Prof. Lester Ingber [10ATT]0-700-L-INGBER || || Lester Ingber Research Fax: 0-700-4-INGBER || || P.O. Box 857 Voice Mail: 1-800-VMAIL-LI || || McLean, VA 22101 EMail: ingber@alumni.caltech.edu || ------------------------------ From: POCHEC%unb.ca@UNBMVS1.csd.unb.ca Date: Mon, 29 Mar 93 16:17:11 AST Subject: Call for Papers Final Call for Participation The 5th UNB AI Symposium August 11-14, 1993 Sheraton Inn, Fredericton New Brunswick Canada We invite researchers from the various areas of Artificial Intelligence, Cognitive Science and Pattern Recognition, including Vision, Learning, Knowledge Representation and Foundations, to submit articles which assess or review the progress made so far in their respective areas, as well as the relevance of that progress to the whole enterprise of AI. Other papers which do not address the theme are also invited. Feature Four 70 minute invited talks and five panel discussions are devoted to the chosen topic: "Are we moving ahead: Lessons from Computer Vision." The speakers include (in alphabetical order) * Lev Goldfarb * Stephen Grossberg * Robert Haralick * Tomaso Poggio Such a concentrated analysis of the area will be undertaken for the first time. We feel that the "Lessons from Computer Vision" are of relevance to the entire AI community. Information for Authors April 10, 1993: Four copies of an extended abstract (maximum of 4 pages including references) should be sent to the conference chair. May 15, 1993: Notification of acceptance will be mailed. July 1, 1993: Camera-ready copy of paper is due. Conference Chair: Lev Goldfarb Email: goldfarb@unb.ca Mailing address: Faculty of Computer Science University of New Brunswick P. O. Box 4400 Fredericton, New Brunswick Canada E3B 5A3 Phone: (506) 453-4566 FAX: (506) 453-3566 Symposium location The symposium will be held in the Sheraton Inn, Fredericton which overlooks the beautiful Saint John River. ------------------------------ From: L. Ridgway Scott Date: Tue, 30 Mar 1993 22:27:55 -0600 Subject: Computer Design: A New Grand Challenge COMPUTER DESIGN: A NEW GRAND CHALLENGE A minitrack of The Architecture Track of the 27th Hawaii International Conference on System Sciences is being organized on the theme of High Performance Computation in the field of Computer Design. Computer manufacturing is a major industrial consumer of computation. The design of VLSI chips is highly dependent on software tools that perform various modeling, optimization and testing functions. Enhancement of these tools to utilize techniques of High Performance Computation can en- hance dramatically the design of new chips and computer systems. The primary object of the Minitrack will be to bring together people who specialize in the use of modern parallel super- computers and computer architects who are using extensive amounts of computing in computer design. Three types of papers are solicited for the Minitrack. One type describes large computations related to computer design and how a significant increase in computational power would dramatically enhance the way computers are designed. Also, papers devoted to improved algorithms will be encouraged provided they are directed to practical computer design issues. And papers on the modification of existing algorithms to achieve reasonable speed- ups on a large number of processors are also solicited. Papers with a mixture of all three aspects especially encouraged. Areas of interests include * Device, Circuit, Logic & Register models of chip function. * Relations between different modeling levels, mixtures of levels. * Optimizing the placement of components and routing of wires. * Testing a final design for correctness. * Supercomputer computation in the design of commercial systems. 1993 Deadlines o Eight copies of the manuscript by June 4 o Notification of accepted papers by August 31 o Camera-ready copies of accepted manuscripts due by October 1 The paper should be sent to Ridgway Scott Department of Mathematics UNIVERSITY OF HOUSTON Houston, TX 77204--3476 phone: 713-743-3445 FAX: 713-743-3505 e-mail: scott@uh.edu If you intend to submit a paper, or are willing to serve as a referee, please respond via e-mail to scott@uh.edu. Papers chosen for the Minitrack will be considered for publication in a special issue of the International Journal of Supercomputer Applications. ------------------------------ From: Dan Zwick Date: Thu, 1 Apr 1993 19:24:51 -0500 (EST) Subject: Workshop on Constrained Approximation and Optimization Workshop on Algorithms for Constrained Approximation and Optimization May 23--26, 1993 Stowe, Vermont The Organizers: D. Zwick, University of Vermont R.A. Zalik, Auburn University We are pleased to announce the "Workshop on Algorithms for Constrained Approximation and Optimization" to be held at the Stowehof Inn, Stowe, Vermont, May 23-26, 1993. This workshop will be funded by the National Science Foundation, with partial support from the University of Vermont. If you would like to attend this exciting workshop, please notify me by email with the topic of your talk and your mailing address, insofar as it differs from the one in the CML. Regretfully, space and time limitations require that we restrict the number of speakers, so attendance is by invitation only. The "Workshop on Algorithms for Constrained Approximation and Optimization" will bring together leading researchers in numerical analysis and approximation theory to discuss new and innovative approaches to solving difficult problems in the area of constrained approximation and optimization. The participants, who will come from academia, private and government research institutes, and industry, are mostly experts in either constrained approximation or constrained optimization. While there is a nonempty intersection in the problems and techniques familiar to these two groups, there has not been much interaction and cross-fertilization between them. The purpose of the proposed workshop is to provide a pleasant and productive setting for participants to engage in an interchange of ideas, to foster collaborative research among the participants, and to expose young researchers and graduate students to the exciting mathematics being done at the forefront of these fields. The conference proceedings will be published either in the "Annals of Numerical Mathematics," a new journal devoted to conference proceedings of this type, or in "Numerical Algorithms," depending on the number of contributed papers. We strongly encourage participants who have sufficient funds to support graduate students, postdocs, and other new researchers at their institutions who might be interested in attending and being exposed to the exciting mathematics being done at the forefront of these fields. Members of this group who do not have their own research funds will be given top priority in the use of the NSF funds. We also wish to make a special effort to reach mathematicians traditionally underrepresented at workshops of this nature---women, members of minorities, and disabled persons---and have been assured that all conference facilities and a number of the rooms are accessible to persons with disabilities. So please help spread the word! Regards, Dan Zwick Dan Zwick Tel: (802) 656-4314 Math Department, Univ of Vermont (802) 658-1978 (home) 16 Colchester Ave. e-mail: zwick@emba.uvm.edu Burlington VT 05401-1455 fax: (802) 656-8802 ------------------------------ From: Daniel B. Szyld Date: Thu, 1 Apr 93 23:07:57 EST Subject: AWM WORKSHOP before SIAM meeting Association for Women in Mathematics (AWM) WORKSHOP AWM will sponsor a Workshop in conjunction with the annual SIAM meeting for women graduate students and postdocs in applied mathematics. It will be similar to the workshops held at major mathematics meetings over the past three years and will be funded by NSF and ONR. The workshop will take place on July 11, 1993, before the SIAM Meeting (July 12 to 16) at the Wyndham Franklin Plaza Hotel in Philadelphia, PA. Funding for travel and subsistence will be offered for up to ten women graduate students and ten women postdocs to attend the AWM Workshop. Those attending are encouraged to stay for the rest of the SIAM meeting. Departments are urged to provide some institutional support. To be eligible for funding, graduate students must have begun work on a thesis problem. Postdocs must have received their Ph.D. within approximately the last five years. All applications should include a curriculum vita and a concise description of research; graduate students should include a letter of recommendation from their advisor. Nominations by other mathematicians (accompanied by the information described above) are welcome. The deadline for applications is April 10, 1993. They should be sent to: Ginny Reinhart, Executive Director, AWM, 4114 Computer & Space Sciences Building, University of Maryland, College Park, MD 20742-2461; (301) 405-7892. ------------------------------ From: Sanzheng Qiao Date: Sun, 4 Apr 93 09:25 EDT Subject: Southern Ontario NA Day ELEVENTH ANNUAL SOUTHERN ONTARIO NUMERICAL ANALYSIS DAY The Eleventh Annual Southern Ontario Numerical Analysis Day is to be hosted at McMaster University, Hamilton, Ontario, on Saturday, May 1, 1993. Gene Golub is our distinguished speaker this year. There are a total of 14 presentations. The program is availabe via anonymous ftp on maccs.dcss.mcmaster.ca (130.113.1.1) under the directory public/seminars/na. Hamilton is located about 60 miles from the Niagara Falls and about 40 miles from Toronto. McMaster University is on the west side of the city. Directions to the city and hotel information can also be found in the directory public/seminars/na. We are planning on having a wine and cheese party on the Friday (April 30) evening. If you are interested in joining us please advise. Sanzheng Qiao Dept. Comp. Sci. & Syst. McMaster University Hamilton, ON L8S 4K1 CANADA qiao@maccs.dcss.mcmaster.ca (416)525-9140 ext. 7234 ------------------------------ From: John Coleman Date: Thu, 01 Apr 93 15:47:54 BST Subject: Lectureships at University of Durham UNIVERSITY OF DURHAM Department of Mathematical Sciences Lectureships in Mathematical Sciences Two or more temporary posts in Mathematical Sciences are available for two years from 1 October 1993, or as soon as possible thereafter. The Department of Mathematical Sciences has active research groups in Pure Mathematics, Mathematical Physics, Numerical Analysis and Statistics, and is committed to excellence in both research and teaching. One post will be in Numerical Analysis. Salaries are likely to be on the Lecturer A scale (13,400 - 18,576 pounds per annum). Further details may be obtained from the Director of Personnel, Old Shire Hall, Durham, DH1 3HP (tel 091 374 3158) to whom applications (three copies, including curriculum vitae and the names of three referees) should be sent, to arrive no later than Tuesday 4 May 1993. Please quote reference A189. (The personnel office will be closed for Easter for the period 8-13 April.) The Numerical Analysis group is part of the Applied Mathematics section of the department which obtained Grade 5 in the recent Research Assessment Exercise. E-mail queries may be addressed to John.Coleman@durham.ac.uk ------------------------------ From: Richard Brualdi Date: Mon, 29 Mar 93 09:35:03 CST Subject: Contents, Linear Algebra and its Applications Linear Algebra and its Applications Contents Volume 185 J. William Helton (La Jolla, California) and Hugo J. Woerdeman (Williamsburg, Virginia) Symmetric Hankel Operators: Minimal Norm Extensions and Eigenstructures 1 Adam W. Bojanczyk, Ruth Onn, and Allan O. Steinhardt (Ithaca, New York) Existence of the Hyperbolic Singular Value Decomposition 21 Mario Taboada (Los Angeles, California) A Theorem in Linear Algebra With Applications to the Geometry of Quadrics 31 Jean-Claude Evard (Laramie, Wyoming) and Frank Uhlig (Auburn, Alabama) Comparison of the Sets of Polynomials p and q Such That X=p(A) and Y=q(B) Are Solutions of the Matrix Equations f(X)=A and f(Y)=B 41 Dragoslav Herceg and Natasa Krejic (Novi Sad, Federal Republic of Yugoslavia) On the Convergence of the Unsymmetric Successive Overrelaxation (USSOR) Method 49 Elizabeth A. Kalinina and Alexei Yu. Uteshev (St. Petersburg, Russia) Determination of the Number of Roots of a Polynomial Lying in a Given Algebraic Domain 1 Leonid Lerer (Haifa, Israel) and Leiba Rodman (Williamsburg, Virginia) Sylvester and Lyapunov Equations and Some Interpolation Problems for Rational Matrix Functions 83 Moody T. Chu (Raleigh, North Carolina) The Stability Group of Symmetric Toeplitz Matrices 119 K. Zietak (Wroclaw, Poland) Subdifferentials, Faces, and Dual Matrices 125 H. Valiaho (Helsinki, Finland) The Boolean Pivot Operation, M-matrices, and Reducible Matrices 143 H. Miranda and Robert C. Thompson (Santa Barbara, California) A Trace Inequality With a Subtracted Term 165 Peter Lancaster (Calgary, Alberta, Canada) and Qiang Ye (Winnipeg, Manitoba, Canada) Rayleigh-Ritz and Lanczos Methods for Symmetric Matrix Pencils 173 James W. Demmel (Berkeley, California) and William Gragg (Monterey, California) On Computing Accurate Singular Values and Eigenvalues of Matrices With Acyclic Graphs 203 Gilbert Helmberg and Peter Wagner (Innsbruck, Austria) and Gerhard Veltkamp (Eindhoven, the Netherlands) On Faddeev-Leverrier's Method for the Computation of the Characteristic Polynomial of a Matrix and of Eigenvectors 219 Wang Xinmin (Beijing, People's Republic of China) Generalized Extrapolation Principle and Convergence of Some Generalized Iterative Methods 235 Hongxiang Li (Shanghai, People's Republic of China) and Gangsong Leng (Changsha, People's Republic of China) Matrix Inequality With Weights and Its Applications 273 Author Index 279 ------------------------------ From: Daniel Baltzer Date: Wed, 31 Mar 1993 10:47:33 -0700 Subject: Contents, Numerical Algorithms Contents NUMERICAL ALGORITHMS, Editor-in-Chief: Claude Brezinski, Laboratoire d'Analyse Numerique et d'Optimisation, UFR IEEA - M3, Universite de Lille 1, France, fax: +33 - 20 43 49 95, e-mail: brezinsk@frcitl81.bitnet Numerical Algorithms, Volume 4 (1993), issues 1,2: Computing the real roots of a polynomial by the exclusion algorithm, J.-P. Dedieu and J.-C. Yakoubsohn On the computation of a versal family of matrices, L. Stolovitch Model reduction techniques for sampled-data systems, F.D. Barb and M.Weiss Automatic solution of regular and singular vector Sturm-Liouville problems, M.Marletta. An efficient Total Least Squares algorithm based on a rank-revealing two-sided orthogonal decomposition, S. van Huffel and H. Zha. On the design of an upwind scheme for compressible flow on general triangulations, Th. Sonar. Fast orthogonal decomposition of rank deficient Toeplitz matrices, P.C. Hansen. A homotopy algorithm for a symmetric generalized eigenproblem, K.Li and T.-Y. Li. A note on the implementation of the successive overrelaxation for linear complementarity problems, W. Niethammer. Requests for free sample copies and orders are to be sent to: J.C. Baltzer AG, fax: +41-61-692 42 62, e-mail: na.baltzer@na-net.ornl.gov ------------------------------ From: Carlos Moura Date: Sat, 3 Apr 93 14:23:02 EST Subject: Contents, Computational and Applied Mathematics COMPUTATIONAL AND APPLIED MATHEMATICS (Matematica Aplicada e Computacional) Vol. 11, Issue 2, 1992 * Special Issue on Conservation Laws * Aparecido J. de SOUZA Stability of Singular Fundamental Solutions under Perturbation for Flow in Porous Media Jesus C. da MOTA The Riemann Problem for a Simple Thermal Model for 2-Phase Flow in Porous Media Eli L. ISAACSON, Dan MARCHESIN, Bradley J. PLOHR and J. BLAKE TEMPLE Multiphase Flow Models with Singular Riemann Problems Heinrich FREISTUHLER Hyperbolic Systems of Conservation Laws with Rotationally Equivariant Flux Function James GLIMM, Brent LINDQUIST, Felipe PEREIRA and Ron PEIERLS The Multi-Fractal Hypothesis and Anomalous Diffusion ------------------------------ End of NA Digest ************************** -------