Subject: NA Digest, V. 95, # 22 NA Digest Sunday, May 28, 1995 Volume 95 : Issue 22 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: Simeon Fatunla A Continuous Choice of an Eigenvalue Spatial Cluster Analysis Tests for Kalman Filter PICL and PSTSWM software updates Report on TICAM Symposium Positions at Bell Labs Postdoctoral Position at Argonne Laboratory Postdoctoral Fellowship in Bologna, Italy Research Studentship at RMCS, Shrivenham Contents, Approximation Theory Contents, Global Optimization Submissions for NA Digest: Mail to na.digest@na-net.ornl.gov. Information about NA-NET: Mail to na.help@na-net.ornl.gov. URL for the World Wide Web: http://www.netlib.org/na-net/na_home.html ------------------------------------------------------- From: John Pryce Date: Thu, 25 May 1995 14:46:01 +0100 (BST) Subject: Simeon Fatunla Grieve, colleagues. On 24th May I received by fax this brief message from Prof James Ezeilo, director of the Nigerian Mathematical Centre in Abuja: " I regret very much to have to report to you the tragic death of our friend and colleague Prof Simeon Fatunla. He died on the spot as a result of a head-on collision of his vehicle with another vehicle at a point on the Auchi-Okene Road on Friday 19 May 1995. His driver also died on the spot. Funeral arrangements are being organized by the University of Benin and we will keep you posted. May Prof Simeon Fatunla's soul rest in peace. James O C Ezeilo " Many people round the world will join with his family and his associates, in mourning the death at age 51 of one of the outstanding men of his generation and a leader of the academic community in his country. I will be in touch with colleagues both from Nigeria and overseas, who have taken part in Simeon's Benin Conferences, to decide what should be done to leave an enduring memorial of his work and to help make permanent what he has begun. John Pryce Software Engineering Group Royal Military College of Science Shrivenham, Swindon, UK 25 May 95 ------------------------------ From: Laurent Bartholdi Date: Mon, 22 May 1995 14:48:24 +0200 Subject: A Continuous Choice of an Eigenvalue I asked myself the following problem, without being able to answer it: ``Does there exist a continous function e from the space of 2x2 complex matrices to the space of complex numbers, such that to each matrix corresponds one of its eigenvalues?'' My first guess was that such a function does not exist. Indeed, take a matrix with two different eigenvalues, for instance A= [0 1] [1 0] (eignenvals +1 and -1), and contruct a 'path in the matrix space', that is a parametrization M(t) = [a(t) b(t)] [c(t) d(t)] such that M(-1) = M(1) = A, a, b, c, d continuous in -1<=t<=1, and e(M(t)) = t, where e is our hypothetical eigenvalue function. This would then show such a function cannot exist, as it would have two different values on A. Unfortunately all my attempts to build one such function have failed, so I have come to doubt my conjecture. Thanks to all, Larry ------------------------------ From: Ira Hammerman Date: Wed, 24 May 95 12:30:29 +0300 Subject: Spatial Cluster Analysis I am looking for efficient algorithms for clustering two points on a two-dimensional plane. Can some recommend 1. algorithms 2. reports 3. books. Much thanks, Ira Hammerman email: ira@is.elta.co.il ------------------------------ From: K. B. Williams Date: Fri, 26 May 1995 18:22:31 -0400 Subject: Tests for Kalman Filter I have written a program that implements the Kalman Filter with Driving Noise. I need a test case that is more complicated than my simple one, yet not overly complex either. Program or literature references would be much appreciated. K. B. Williams Kbwms@aol.com ------------------------------ From: Pat Worley Date: Wed, 24 May 1995 12:48:20 -0400 Subject: PICL and PSTSWM software updates PICL and PSTSWM software updates: PICL PICL v2.1 is now available from http://www.epm.ornl.gov/picl . The primary differences between versions 2.0 and 2.1 are new ports for the IBM SP multiprocessors and for the Cray Research T3D. The SP port is built on top of MPL, while the T3D port is built on top of the Cray Research multiprocessor implementation of PVM. README files are provided with the source code distribution that describe how to compile and use PICL in the new environments. The Portable Instrumented Communication Library (PICL) is an instrumented, low overhead message-passing compatibility library, supporting both portable message-passing and portable performance data collection without incurring unnecessary overhead. PICL is a research tool developed for and used in projects in performance evaluation and high performance computing, and is made available to the community as a research tool. (It is not a product.) In my own work, PICL is used for portability when the underlying native communication library is a good match to the PICL semantics. When the most efficient native library is not a good match, like SHMEM on the T3D, I still use PICL for collecting performance data on the user-level events. An example of this usage can be found in PSTSWM, described below. PSTSWM PSTSWM v4.0 is now available from http://www.epm.ornl.gov/chammp/pstswm . (It has been available for awhile, but the user guide has just been updated.) PSTSWM is a message-passing benchmark code and parallel algorithm testbed that solves the nonlinear shallow water equations on a rotating sphere using the spectral transform method. PSTSWM was developed by to evaluate parallel algorithms for the spectral transform method as it is used in global atmospheric circulation models. Multiple parallel algorithms are embedded in the code and can be selected at run-time, as can the problem size, number of processors, and data decomposition. This flexibility allows the code to be tuned on a parallel platform before benchmarking, thus evaluating the multiprocessor on its ability to solve the numerical problem rather than it ability to execute a given fixed parallel implementation. Six different problem test cases are also supported, each with associated reference solutions and solution and error analysis options. As of 4/1/95, PSTSWM runs on the Cray Research T3D, the IBM SP-1 and SP-2, the Intel iPSC/2, iPSC/860, DELTA, and Paragon (on both GP and MP nodes and using either the NX or SUNMOS operating systems), the nCUBE/2 and nCUBE/2S, across a network of SUN and IBM workstations, and on a Cray vector machine (as a serial application). Message passing is implemented using MPI, PICL, PVM, and/or native message passing libraries, with the choice being made at compile time. In principle, it should also run on any other platform on which MPI, PICL, or PVM is available. To aid in tuning and in understanding the parallel performance, PSTSWM has been instrumented for the collection of performance data using the PICL trace and profile collection interface. The PICL implementation of the code must be used in order to collect performance data on interprocessor communication but a mixed PICL/native implementation is also provided that can be used to collect data on events not related to message passing. In the mixed implementation, the performance sensitive message passing uses native commands and PICL is only used in the collection of the performance data. For more information or for alternative ways of acquiring source code, contact: Pat Worley worleyph@ornl.gov ------------------------------ From: Richard Lehoucq Date: Thu, 25 May 1995 09:24:58 -0500 (CDT) Subject: Report on TICAM Symposium The Symposium on Advances and Trends in Computational and Applied Mathematics, sponsored by the Texas Institute for Computational and Applied Mathematics (TICAM), was held April 20-22, 1995 in Austin, Texas. The symposium focused on the many interdisciplinary topics that bring together applied mathematics, numerical analysis, computational sciences, physics, and engineering. The symposium also helped to introduce the recently established academic and research program in Computational and Applied Mathematics (CAM) at The University of Texas at Austin. Drawing faculty together from the Natural Sciences and Engineering, it provides an important new opportunity for instruction and research in this rapidly growing area. The program is interdisciplinary and consists of faculty representatives from six engineering departments, as well as the departments of Computer Sciences, Mathematics and Physics with contributions from Chemistry and Astronomy. The program offers study leading to both the Ph.D. and Master of Science degrees. An important component in the CAM program is the initiation of a new research institute, the Texas Institute for Computational and Applied Mathematics (TICAM). TICAM is an organized research unit drawing research faculties and students from the participating departments. Interdisclipinary research projects include large-scale parallel computing, structural acoustics, computational fluid dynamics, computer simulation of micro-structure of composite materials, and ongoing projects in computational physics. The two and half day symposium was structured around a number of thirty minute keynote presentations. Each day also included parallel sets of contributed sessions. The contributing speakers were given fifteen minutes to discuss their research. The organizers assembled an impressive group of computational scientists for the symposium. Although the backgrounds of all the speakers varied, the title of computational scientist could aptly be used for all since the use of computing was of central importance to the presentations. Indeed, there was such diversity among the talks that only a few could claim to not have learned something new about areas outside their own. The symposium organizers are to be commended for a well coordinated event. The overall quality and content of the presentations was high. To give the reader an idea of the breath of the talks, the following quickly reviews the symposium and subjects of each of the keynote presentations. Starting off the first day was Dr. Marye Anne Fox of the University of Texas at Austin with a warm welcome for all the attendees. Professor Tinsley Oden, the director of TICAM, followed with a brief introduction to the activities and mission of the institute. The first keynote talk was given by Jerry Bona of the University of Texas at Austin. He considered the modeling of some of the aspects of near-shore coastal dynamics. The goal was understanding how seashores erode over time. In the second talk, Gene Golub of Stanford University discussed the many applications of the theory of moments in numerical analysis. One application is the efficient and stable computation of the elements of the inverse of a symmetric matrix. Professor Golub mentioned current research is underway that uses these estimates for determining preconditioners for linear systems. Professor T.J.R. Hughes, also of Stanford University followed with a talk concerning multi-scale phenomena. The presentation examined a methodology for capturing the various scales of phenomena in the finite element modeling of physical processes. Jack Dongarra of the University of Tennessee and Oak Ridge National Laboratory next discussed the SCALAPACK project. SCALAPACK is the porting of the LAPACK software package onto parallel computers, in particular, massively parallel computers. Professor Dongarra discussed the many issues that arise in such an undertaking. Starting off the afternoon session, Professor Bjorn Engquist of the University of California, Los Angeles talked about multi-phase computations in geometrical optics. Attempting to capture as much of the frequency component of various equations describing geometrical optics through different numerical schemes was discussed. Professor P. Netaanmaki then followed with an overview of the work of the Laboratory of Scientific computing he directs at the University of Jyvaskyla, Finland. One particular research area he addressed was that of problems in nonlinear optimal control. The final keynote talk of the day was given by John Whiteman of Brunel University, United Kingdom, on discrete schemes for hereditary problems of viscoelasticity. Professor Whiteman's talk typified the synthesis of engineering, science and computational mathematics of all the talks. The day concluded with a reception at the Lila B. Etter Alumni center. The second day of the symposium was started with a talk by Mary Wheeler of Rice University. Professor Wheeler gave an overview of the research being undertaken by her group on flow through porous media. Applications include remediation of soils and aquifers and oil recovery. Simulating the manufacturing process in microlithography was the subject of the next talk given by Steven Orszag of Princeton University. Professor James Bramble of Texas A&M University then followed with a mathematical talk on the subject of least squares methods for Stokes equations. The fourth talk of the day was given by David Young of the University of Texas at Austin. The parallel implementation of alternating-type iterative solution methods were discussed. The last keynote presentation before lunch was given by Richard Ewing of Texas A&M University. Professor Ewing discussed an interesting categorization of the multidisciplinary approach being used to solve problems in environmental modeling. Following a break for lunch, Randy Bank of the University of San Diego, La Jolla, examined the many issues involved in the design of an algorithm for coarsening unstructured meshes. Professor Tinsley Oden's talk followed and considered parallel hp-adaptive methods for viscous flow. The methods described provide efficient and robust criteria for deciding when to refine the mesh in an adaptive fashion and increase the degree of the finite elements employed. The goal was to develop a local error estimator to obtain near optimal convergence rates. Professor Owe Axelsson of the University of Nijmegen gave the last keynote presentation of the day. A detailed study was given on developing scalable parallel multilevel algorithms for problems arising from fluid flow. The day was concluded with presentations by the contributing speakers. The symposium then retired to a reception at the Faculty center followed by a banquet. Ivo Babuska of the University of Maryland gave the first keynote presentation of Saturday morning. Professor Babuska considered the many complexities when using the finite element method on domains with unsmooth boundaries and interfaces as well as the impact of rough coefficients. The next hour was devoted to sessions by the contributing speakers. Advances in element free and particle methods was the subject of the talk given by Professor Ted Belytschko of Northwestern University. Professor G.F. Carey of the University of Texas at Austin presented a survey and review of the many numerical schemes for non-Newtonian flows. The final keynote presentation of the symposium was given by Peter Pinsky of Stanford University. He addressed the use of Galerkin least squares methods for Hydrodynamic semiconductor device equations. Professor Oden then concluded the half day session with some closing remarks. In particular, he asked all the symposium attendees to thank Ms. Ruth Hengst for a successful coordination of the event. Finally, Professor Oden mentioned that a future issue of the Journal of Computational and Applied Mathematics will contain papers by the keynote speakers on their presentations. (The author gratefully acknowledges Gene Golub and Ruth Hengst for their comments on this report.) ------------------------------ From: Jiming Liu Date: Wed, 24 May 95 11:06:40 EDT Subject: Positions at Bell Labs The Advanced Decision Support System (ADSS) organization at AT&T Bell Labs is interested in outstanding candidates who are considering consulting and development careers in Operations Research and Computer Science. AT&T Bell Labs ADSS has a long record of developing large-scale decision support systems and providing optimization-based consulting, object oriented design and software development, and implementation of client/server architectures. We have 3-4 openings for regular employees as well as for post-doctoral positions with a possibility of converting to regular employee positions. What AT&T Bell Labs ADSS requires: Education: Advanced degree (M.S. or Ph.D.) in Operations Research, Computer Science or related field required. In addition, an undergraduate degree in Engineering is desirable. OR Expertise: Practical experience and a theoretical background in general optimization and/or stochastic processes required. Knowledge of network analysis, system design and analysis, decision support systems, and basic statistical analysis desirable. Work Experience: A minimum of 2 years of non-academic professional experience required (may be waived for an applicant with a Ph.D.). Experience in the telecommunication area is desired. Previous consulting experience a plus. Computer Skills: Proficiency in programming C++ or C required. Knowledge of UNIX, object-oriented methodology, use of state-of-the-art optimization and statistical packages desirable. Experience with graphics and spreadsheets a plus. General: Highly developed oral and written communication skills as well as excellent interpersonal skills. Willingness to learn, self-motivation, and self-management, What AT&T Bell Labs ADSS can offer: A challenging and informal work environment. Work on leading-edge problems, develop innovative decision technologies, using the latest in high-performance commercial software technology (object oriented development, etc.). An opportunity to make an impact in a leading industrial laborotory environment. Competitive salaries, excellent benifits, and exciting career growth. If your background and interests match these expectations, please send your resume via fax, e-mail or regular mail to: Jiming Liu AT&T Bell Laboratories Room 2L-320 101 Crawfords Corner Road Holmdel, NJ 07733 e-mail. jiming@kingfish.att.com fax. 908-949-4001 ------------------------------ From: Chris Bischof Date: Thu, 25 May 1995 15:47:39 -0500 Subject: Postdoctoral Position at Argonne Laboratory POSTDOCTORAL POSITION MATHEMATICS AND COMPUTER SCIENCE DIVISION ARGONNE NATIONAL LABORATORY Argonne National Laboratory has openings for postdoctoral research positions in the Mathematics and Computer Science Division and invites outstanding candidates to apply. One position is expected to be on assignment at the Supercomputing Research Center in Bowie, Maryland. Candidates should have a Ph.D. in applied mathematics, computer science, computational chemistry or a related discipline and comprehensive knowledge in numerical linear algebra and parallel computing. The successful candidate will participate in the development of algorithms and software tools for large-scale dense eigenvalue and orthogonal reduction problems under the umbrella of the PRISM (Parallel Research in Invariant Subspace Methods) project. Information on the PRISM project can be found in pub/prism on ftp.super.org. This project is interdisciplinary in nature and interfaces with efforts in computational chemistry. The Mathematics and Computer Science Division supports an excellent computational environment that includes access to high-performance scientific workstations, a scientific visualization and virtually reality laboratory, and state-of-the-art parallel computers. Argonne is located in the southwestern Chicago suburbs, offering the advantages of affordable housing and good schools, as well as easy access to the cultural attractions of the city. Applicants must have received their Ph.D. not more than three years prior to the beginning of the appointment. The appointment is available immediately and for a one-year term (renewable). Applications should be addressed to Walter McFall, Box mcs-postdoc9, Employment and Placement, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, and must include a resume' and the names and addresses of three references. For additional information, contact Chris Bischof (bischof@mcs.anl.gov). Argonne is an affirmative action/equal opportunity employer. ------------------------------ From: Antonio Messina Date: Fri, 26 May 1995 08:35:30 -0600 Subject: Postdoctoral Fellowship in Bologna, Italy Postdoctoral Research Fellowships Numerical Magnetohydrodynamics The EEC ``Human Capital and Mobility'' program has established a numerical MHD grant, which will finance one-year fellowships in different laboratories. The grant supports collaborations in the following principal areas: MHD Flows and Turbulence Dynamos Thermal Convection Interstellar Medium; Stellar Winds; Solar Wind and Corona Numerical Techniques for MHD The fellowships are intended for citizens of the member states of the European Community and associated states. The salary and associated research costs will be at the standard rate of each state. Candidates may not apply in their own country; they should write directly to the group providing their curriculum vitae, a list of recent publications, two letters of recommendation and a statement of research interests. This call is for a one-year position at the University of Bologna, Dip. Fisica, the deadline for receipt of applications is June 20th 1995. Contact names: P. Londrillo, Osserv. astron. di Bologna, via Zamboni 33, 40126 Bologna, Italy. Email: 37907::londrillo, londrillo@astbo3.bo.astro.it; tel. (39) 51 6305720. A. Messina, Dip. Fisica, via Irnerio 46, 40126 Bologna, Italy. Email: messina@isoar.df.unibo.it; tel. (39) 51 6305212, fax: (39) 51 6305212. COMPUTING RESOURCES: Cray T3D MCA 64-8, Cray C92/2128 SSD, cluster of graphic ws ------------------------------ From: Rod Smith Date: Fri, 26 May 1995 14:59:44 +0100 (BST) Subject: Research Studentship at RMCS, Shrivenham ROYAL MILITARY COLLEGE OF SCIENCE CRANFIELD UNIVERSITY APPLIED MATHEMATICS AND OPERATIONAL RESEARCH GROUP Research studentship in numerical mathematics/scientific computing Applications are invited for the above studentship, which is for fees and a maintenance bursary of approximately seven thousand pounds per annum. The Applied Mathematics and Operational Research Group is part of the Royal Military College of Science (RMCS) situated at Shrivenham in the Vale of the White Horse district of Oxfordshire. The College is a faculty of Cranfield University and the research student will be registered for a Cranfield degree. Techniques of particular interest to the group are the numerical solution of integral equations, including boundary element methods; finite element and finite difference methods and approximation and data fitting including neural networks. Work on boundary elements has been continuing since 1980 with the focus on numerical techniques, applications in fracture mechanics, free surface problems in fluid mechanics and electrodeposition. It is envisaged that the student will embark on research in the application of modern computing techniques to the development of more efficient boundary element methods. The research may encompass numerical integration techniques, parallel processing and adaptive meshing and will require extensive programming in Fortran 90. Although previous experience of boundary element methods is not required, a strong mathematics/numerical analysis background with a good grounding in computer programming is essential. Applicants should have (or expect to obtain this summer) at least an upper second class honours degree or an equivalent postgraduate qualification. For further information or to apply for the position please contact Dr Rod Smith/Dr.Venkat V S S Sastry, AMOR group, RMCS Shrivenham, Swindon, Wilts SN6 8LA, UK {smith,sastry}@rmcs.cran.ac.uk Tel:044 01793 785312 Fax:044 01793 782179 ------------------------------ From: Marilyn Radcliff Date: Tue, 23 May 1995 10:56:57 -0400 (EDT) Subject: Contents, Approximation Theory Table of Contents: J. Approx. Theory, Volume 81, Number 1, April 1995 J. Bustamante and G. Lopez Lagomasino Hermite-Pade approximation to a Nikishin type system of meromorphic functions 1--12 Vladimir A. Operstein A characterization of smoothness in terms of approximation by algebraic polynomials in $L_p$ 13--22 H.-B. Knoop and Xin-Long Zhou On convergence of Hermite-Fej\'er interpolation polynomials 23--37 Amos Ron Approximation orders of and approximation maps from local principal shift-invariant spaces 38--65 Peter Borwein and Tam\'as Erd\'elyi Dense Markov spaces and unbounded Bernstein inequalities 66--77 A. L. Brown Metric projections in spaces of integrable functions 78--103 Knut Petras Duality and lower bounds for relative projection constants 104--119 Timur Oikhberg Absolute widths of some embeddings 120--126 L. Brutman and E. Passow On the divergence of Lagrange interpolation to $|x|$ 127--135 Notes Gancho T. Tachev A note on two moduli of smoothness 136--140 Margarita Nikoltjeva-Hedberg and Vladimir Operstein A note on convex approximation in $L_p$ 141--144 Ryszard Szwarc A lower bound for orthogonal polynomials with an application to polynomial hypergroups 145--150 ============ Table of Contents: J. Approx. Theory, Volume 81, Number 2, May 1995 Grzegorz Lewicki Best approximation in finite dimensional subspaces of $L(W,V)$ 151--165 Kang Zhao Simultaneous approximation from PSI spaces 166--184 S.P. Zhou On rational lacunary approximation on the interval $[-1,1]$ 185--194 Herman Bavinck and Roelof Koekoek On a difference equation for generalizations of Charlier polynomials 195--206 F. M\'oricz A quantitative version of the young test for the convergence of conjugate series 207--216 Ying Guang Shi Bounds and inequalities for arbitrary orthogonal polynomials on finite intervals 217--230 Jutta Faldey and Wolfgang Gawronski On the limit distributions of the zeros of Jonqui\'ere polynomials and generalized classical orthogonal polynomials 231--249 Oleg V. Davydov A class of weak Chebyshev spaces and characterization of best approximations 250--259 H. T. Koelink and R. F. Swarttouw A $q$-analogue of Graf's addition formula for the Hahn-Exton $q$-Bessel function 260--273 J. M. Carnicer and J. M. Pe\~na On transforming a Tchebycheff system into a strictly totally positive system 274--295 Note Ryszard Szwarc Uniform subexponential growth of orthogonal polynomials 296--302 ------------------------------ From: Panos Pardalos Date: Wed, 24 May 1995 20:41:13 -0400 Subject: Contents, Global Optimization Table of Contents JOURNAL OF GLOBAL OPTIMIZATION (Kluwer Academic Publishers) Vol. 6 No. 3, 1995 FAIZ A. AL-KHAYYAL, CHRISTIAN LARSEN, and TIMOTHY VAN VOORHIS / A Relaxation Method for Nonconvex Quadratically Constrained Quadratic Programs 215-230 HAROLD P. BENSON / A Geometrical Analysis of the Efficient Outcome Set in Multiple Objective Convex Programs with Linear Criterion Functions 231-251 ANA FRIEDLANDER, JOSE MARIO MARTINEZ, and SANDRA AUGUSTA SANTOS / Solution of Linear Complementarity Problems Using Minimization with Simple Bounds 253-267 R. GONZALEZ, E. ROFMAN, and C. SAGASTIZABAL / Global Optimization of Arborescent Multilevel Inventory Systems 269-292 JAROSLAW KOSTROWICKI and HAROLD A. SCHERAGA / Simple Global Minimization Algorithm for One-Variable Rational Functions 293-311 MOSHE SNIEDOVICH and SUZANNE FINDLAY / Solving a Class of Multiplicative Programming Problems via C-Programming 313-319 Book Reviews P.D. PANAGIOTOPOULOS/ Hemivariational Inequalities: Applications in Mechanics (V.F. DEMYANOV) 321-323 Contents of all other issues can be found using gopher.wkap.nl. ------------------------------ End of NA Digest ************************** -------