Send mail to: mgnet@cs.yale.edu for the digests mgnet-requests@cs.yale.edu for comments or help Anonymous ftp repository: ftp.ccs.uky.edu (128.163.209.106) World Wide Web: http://www.mgnet.org or http://www.cerfacs.fr/~douglas/mgnet.html or http://phase.etl.go.jp/mgnet or http://www.ccs.uky.edu/mgnet Today's editor: Craig Douglas (douglas-craig@cs.yale.edu) Volume 8, Number 11 (approximately November 30, 1998) Today's topics: Available papers on MG (Braess et al) Four Preprints from Sang, Zhang, and Zhang VIGRE Faculty and Graduate Student Positions at Penn State Call for Papers -- Intl. Conf. on Preconditioning Techniques Positions at the SMU Mathematics Department First Announcement for DD12 in Japan Graduate Research Assistant Positions at Los Alamos National Laboratory, Spring 1999 ------------------------------------------------------- Date: Thu, 12 Nov 1998 12:03:26 +0100 From: braess@num.ruhr-uni-bochum.de (Dietrich Braess) Subject: Available papers on MG The following papers on multigrid algorithms can be downloaded from my web-page http://homepage.ruhr-uni-bochum.de/Dietrich.Braess/ftp.html [You will find there also corrections to my book on finite elements.] Papers ====== Towards algebraic multigrid for elliptic problems of second order. Computing 55, 379-393 (1995) An Efficient Smoother for the Stokes Problem (joint paper with R. Sarazin). Applied Numerical Math. 23, 3-20 (1997) Preprints of submitted papers ========= A Cascade algorithm for the Stokes equation (joint paper with W. Dahmen). Numer. Math. (to appear) A multigrid algorithm for the mortar finite element method (joint paper with W. Dahmen and C. Wieners) Stability Estimates of the Mortar Finite Element Method for 3-Dimensional Problems (joint paper with W. Dahmen). East-West J. Numer. Math. (to appear 1998) Multigrid Method for Nonconforming FE-Discretisations with Application to Nonmatching Grids. (joint paper with M. Dryja and W. Hackbusch). ------------------------------------------------------- Date: Sat, 28 Nov 1998 23:51:30 -0500 (EST) From: Jun Zhang Subject: Four Preprints from Sang, Zhang, and Zhang The following preprints are available. Convergence Proof of Jacobi Iterative Method for A Discretized 2D Convection-Diffusion Equation Deyu Sang Department of System Engineering and Applied Mathematics Chongqing University Chongqing 400044, P. R. China Jun Zhang Department of Computer Science University of Kentucky Lexington, KY 40506-0046, USA Shiqing Zhang Department of System Engineering and Applied Mathematics Chongqing University Chongqing 400044, P. R. China ABSTRACT We prove that the Jacobi iterative method converges from any initial values for solving the linear system resulting from a fourth-order compact finite difference discretization of the 2D convection-diffusion equation with constant convection coefficients. The convergence is assured regardless of the magnitude of the convection coefficients and the discretization mesh. This proof confirms the unconditional stability (convergence) of the 2D fourth-order compact scheme (with respect to classical iterative methods), a fact that has only been verified numerically but evaded rigorous justification for almost two decades. * * * * * A Sparse Approximate Inverse Technique for Parallel Preconditioning of General Sparse Matrices Jun Zhang Department of Computer Science University of Kentucky Lexington, KY 40506-0046, USA ABSTRACT A sparse approximate inverse technique is introduced to solve general sparse linear systems. The sparse approximate inverse is computed as a factored form and used as a preconditioner to work with some Krylov subspace methods. The new technique is derived from a matrix decomposition algorithm for inverting dense nonsymmetric matrices. Several strategies and special data structures are proposed to implement the algorithm efficiently. Sparsity patterns of the the factored inverse are exploited to reduce computational cost. The computation of the factored sparse approximate inverse is relatively cheaper than the techniques based on norm minimization techniques. The new preconditioner possesses much greater inherent parallelism than traditional preconditioners based on incomplete LU factorizations. Numerical experiments are used to show the effectiveness and efficiency of the new sparse approximate inverse preconditioner. * * * * * Sparse Approximate Inverse and Multi-Level Block ILU Preconditioning Techniques for General Sparse Matrices Jun Zhang Department of Computer Science University of Kentucky Lexington, KY 40506-0046, USA ABSTRACT We investigate the use of sparse approximate inverse techniques in a multi-level block ILU preconditioner to design a robust and efficient parallelizable preconditioner for solving general sparse matrices. The resulting preconditioner retains robustness of the multi-level block ILU preconditioner (BILUM) and offers a new way to control the fill-in elements when large size blocks (subdomains) are used to form block independent set. Moreover, the new preconditioner affords maximum parallelism for operations within each level as well as for the coarsest level solution. Thus it has two advantages over the BILUM preconditioner: the ability to control sparsity and increased parallelism. * * * * * Preconditioned Krylov Subspace Methods for Solving Nonsymmetric Matrices from CFD Applications Jun Zhang Department of Computer Science, University of Kentucky Lexington, KY 40506-0046, USA ABSTRACT We conduct experimental study on the behavior of several preconditioned iterative methods to solve nonsymmetric matrices arising from computational fluid dynamics (CFD) applications. The preconditioned iterative methods consist of Krylov subspace accelerators and a powerful general purpose multi-level block ILU (BILUM) preconditioner. The BILUM preconditioner and an enhanced version of it are modified slightly from their original versions to precondition different Krylov subspace methods. We choose to test three popular transpose-free Krylov subspace methods: BiCGSTAB, GMRES and TFQMR. Numerical experiments using several sets of test matrices arising from various realistic CFD applications are reported. * * * * * Postscript version of the above 4 preprints can be downloaded from Jun Zhang's homepage at http://www.cs.uky.edu/~jzhang For those who do not have access to web, please send an e-mail to jzhang@cs.uky.edu for a postscript file or a hard copy. ------------------------------------------------------- Date: Wed, 11 Nov 1998 13:18:17 -0500 From: "Douglas N. Arnold" Subject: VIGRE Faculty and Graduate Student Positions at Penn State With the support of an NSF VIGRE grant, the Department of Mathematics at Penn State is seeking to fill several Research Assistant Professorships and graduate fellowships. The Center for Computational Mathematics and Applications plays a major role in the Penn State VIGRE program, and applications are welcome from scientists in computational, numerical, and applied mathematics and from students wishing to work in these areas. Multilevel methods are, in particular, a strong research thrust here. Three S. Chowla Research Assistant Professors will be appointed beginning August 1999. Two are supported by the NSF and are therefore limited to US citizens and permanent residents. Chowla Assistant Professors are expected to be new or recent Ph.D.s with exceptional research potential and a commitment to education. The starting salary is $43,000 for nine months and an annual research stipend will be provided. The NSF-supported Chowla Professors will receive a summer research salary. The teaching load for all the positions is between two and three courses per year. The teaching, and indeed the whole Chowla program, will be designed to maximize the professional development of the participants. The graduate fellowships, called VIGRE Traineeships, include an annual stipend of $17,500 per year, a small and carefully thought out teaching component, and careful mentoring. They are open to US citizens and permanent residents. In addition, the Penn State Department of Mathematics is seeking to fill regular faculty positions at all level and offers a variety of other graduate fellowships. For more information on the Penn State VIGRE program see www.math.psu.edu/vigre/. For more information on the Center for Computational Mathematics and Applications see www.math.psu.edu/ccma/. ------------------------------------------------------- Date: Thu, 12 Nov 1998 12:44:57 -0600 (CST) From: Yousef Saad Subject: Call for Papers -- Intl. Conf. on Preconditioning Techniques TITLE: 1999 INTERNATIONAL CONFERENCE ON PRECONDITIONING TECHNIQUES FOR LARGE SPARSE MATRIX PROBLEMS IN INDUSTRIAL APPLICATIONS DATE: June 10 - 12, 1999 PLACE: University of Minnesota, Hubert H. Humphrey Institute, Minneapolis, Minnesota Please consult the web-site http://www2.msi.umn.edu/Symposia/sparse99/main.html for detailed information. CONFERENCE TOPICS: o Incomplete factorization preconditioners o Domain decomposition preconditioners o Approximate inverse preconditioners o Multi-level preconditoners o Preconditioning techniques in optimization problems o Preconditioning techniques in finite element problems o Preconditioning techniques in image processing o Applications in Computational Fluid Dynamics (CFD) o Applications in computational finance o Multiphase subsurface flow applications o Applications in petroleum industry o Applications in semiconductor device simulation IMPORTANT DATES: * February 26th, 1999 : deadline for submission of extended abstracts. Extended abstracts should be 7 pages maximum. mail to: Sparse-99 MSI 1200 Washington ave. S Minneapolis, MN 55415 Electronic submission encouraged. Send papers (post-script) to sparse99@msi.umn.edu. * March 22nd, 1999: Notification of acceptance. Review will be based on quality of paper and relevance to the conference theme. * April 5th, preliminary program posted * May 7, 1999, deadline for early registration. Early registration is $175, regular registration will be $210. Some support may be available for students interested in attending this conference. Details will be announced as soon as they are available. ------------------------------------------------------- Date: Thu, 19 Nov 1998 08:02:26 -0600 From: Subject: Positions at the SMU Mathematics Department Southern Methodist University Department of Mathematics Applications are invited for two tenure-track assistant professor positions to begin in the Fall semester of 1999. Applicants must provide evidence of outstanding potential for research in applied mathematics and a strong commitment to teaching at all levels. The Department of Mathematics has an active doctoral program in applied mathematics, specializing in physical applied mathematics, numerical mathematics and scientific computation. Research interests include fluid mechanics, nonlinear dynamics and the computational aspects of ordinary and partial differential equations. For one position, preference will be given to candidates whose research has an applied component related to industrial applications and/or to other sciences or engineering. The second position is open to any applied mathematician whose research is closely related to the current interests in the department. To apply, send a letter of application with a curriculum vita, a list of publications, a research statement and a teaching statement to: The Faculty Search Committee, Department of Mathematics, Southern Methodist University, P. O. Box 750156, Dallas, Texas 75275-0156. Applicants must also arrange for three letters of recommendation to be forwarded to the Faculty Search Committee. The committee will begin its review of the applications on or about January 5, 1999. To ensure full consideration for the position, the application must be postmarked on or before January 5, 1999. SMU is an Equal Opportunity/Affirmative Action/Title IX Employer. Visit the Department's WWW site at http://www.smu.edu/~math, and contact the Search Committee by sending e-mail to mathsearch@mail.smu.edu. [Tel:(214)768-2506; Fax:(214)768-2355]. Professor Ian Gladwell, Chair, Dept of Math, SMU, Dallas, TX 75275-0156; Phone: (214)768-2506 Fax: (214)768-2355; email: gladwell@seas.smu.edu www.smu.edu/~igladwel/ ------------------------------------------------------- Date: Thu, 19 Nov 1998 12:51:31 +0900 From: "Hideo Kawarada" Subject: First Announcement for DD12 in Japan First Announcement and Call for Papers 12th International Conference on Domain Decomposition Methods October 25-29, 1999 Chiba University Chiba, Japan Domain Decomposition (DD) as a trigger for enhancement of original concepts and methodologies in computational science and engineering should be regarded as more important. The objective of this conference lies in the promotion of studies based on an active use of DD for the solution of problems arising in various fields of applicable sciences and engineering in liaison with people who share the above mentioned ideas. The conference will include invited plenary talks by leading experts in the field from academia, research institutions, and industry, and also mini-symposia, contributed papers and graduate student papers sessions. In particular, it will focus on: Conference Themes Domain decomposition in science and engineering. Industrial implementation in large scale codes. Theoretical developments. Parallel algorithms and their implementation. Comparisons and demonstrations of actual codes in realistic situations. Multi level methods. Parallel machine architecture. Application Topics Acoustics and electronics Particulate flows Parallel processing Coupled phenomena Car industry applications Micro-electronics applications Bio applications Dimension reduction Multi level methods in optimization DDM and multi level methods in control Conference Deadlines Proposals for mini-symposia February 28 Proposals for contributed papers March 31 Proposals for exhibition May 31 Early registration August 31 Registration September 30 Proposals for Mini-symposia Mini-symposia will be 2 hour sessions of 3-5 speakers focussing on a single topic. The organizer of each mini-symposium will invite the speakers and decide on the topics to be addressed. Proposals for mini-symposia can be submitted via email to dd12@applmath.tg.chiba-u.ac.jp. Session title, organizer, names of speakers and a summary of the topic should be included in the email. Proposals for Contributed Papers If you wish to present a paper (including graduate student paper), please submit an abstract (one page up to 400 words in plain text or Postscript file) via email to dd12@applmath.tg.chiba-u.ac.jp. Conference Web Page The web site of the conference contains up-to-date information. http://applmath.tg.chiba-u.ac.jp/dd12/ Scientific Committee P. E. Bjorstad (Chairperson, Bergen, Norway) J. H. Bramble (Texas A&M, USA) T. F. Chan (UCLA, USA) P. Deuflhard (ZIB, Germany) R. Glowinski (Houston, USA) R. Hoppe (Augsburg, Germany) H. Kawarada (Chiba, Japan) D. E. Keyes (ODU, USA) Y. Kuznetsov (Houston, USA) J. Periaux(St Cloud, France) O. Pironneau (Paris VI, France) Z. C. Shi (Academia Sinica, China) O. Wildlund (Courant Inst., USA) J. Xu (Penn State, USA) Local Organizing Committee I. Hagiwara (TIT) T. Ikeda (Ryukoku Univ.) H. Imai (Tokushima Univ.) T. Kako (UEC) H. Kawarada (Chairperson, Chiba Univ.) H. Koshigoe (Chiba Univ.) M. Mori (Kyoto Univ.) M. Nakamura (Nihon Univ.) H. Okamoto (Kyoto Univ.) M. Tabata (Kyushu Univ.) G. Yagawa (Univ. of Tokyo) Contact Information Mrs. Akemi Tonomura, Institute of Applied Mathematics, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba, 263-8522, JAPAN Email : dd12@applmath.tg.chiba-u.ac.jp TEL&FAX: +81-43-290-3505 ------------------------------------------------------- Date: Mon, 16 Nov 1998 10:32:14 -0700 (MST) From: delong@lanl.gov Subject: Graduate Research Assistant Positions at Los Alamos National Laboratory, Spring 1999 Graduate Research Assistant Positions Los Alamos National Laboratory (PARALLEL COMPUTATION AND NUMERICAL LINEAR ALGEBRA) The Scientific Computing Group (CIC-19) at Los Alamos National Laboratory is currently seeking highly motivated graduate students to participate in the Graduate Research Assistant (GRA) program for the Spring 1999 semester. Graduates with experience in any or all of the following categories are encouraged to apply: Iterative Linear Equation Solvers Multigrid Methods Numerical Linear Algebra Parallel Computer Programming Parallel Software Engineering and Library Development Experience with Fortran 90, C++ and MPI on parallel machines such as the SGI/Cray Origin 2000 and workstation clusters is desirable. Experience with iterative linear solver methods such as conjugate gradient methods, domain decomposition methods and multigrid methods is also desirable. Eligibility for the GRA program is limited to applicants who have completed a bachelors degree by date of hire, and have been admitted to or have active status in a graduate program at a college or university. Students that have completed a Masters degree and have not yet been accepted into another graduate program may be eligible for the Post Masters program and are also encouraged to apply. Appointments are for 90 days up to one year. Salary ranges from $29,000 to $41,000, depending on the number of years of graduate school completed. We are currently unable to hire foreign nationals from the following countries: Algeria, Armenia, Azerbaizan, Belarus, China, Cuba, Georgia, India, Iran, Iraq, Israel, Kazakhstan, Kyrgyzstan, Libya, Moldova, North Korea, Pakistan, Russia, Sudan, Syria, Taiwan, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan. Applications must be received as soon as possible to be given fullest consideration. Interested individuals are encouraged to send a copy of their resume by electronic mail, fax, or U.S. mail to: Mike DeLong Los Alamos National Laboratory Group CIC-19, MS B256 Los Alamos, NM 87545 EMAIL: delong@lanl.gov FAX: (505) 667-1126 Los Alamos National Laboratory is an equal opportunity employer. ------------------------------ End of MGNet Digest **************************