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.ccs.uky.edu/mgnet or http://na.cs.yale.edu/mgnet/www/mgnet.html or http://www.cerfacs.fr/~douglas/mgnet.html or http://phase.etl.go.jp/mgnet Today's editor: Craig Douglas (douglas@ccs.uky.edu) Volume 7, Number 9 (approximately September 30, 1997) Today's topics: MGNet anonymous ftp site moves Correction from Last Issue Two Papers from Jun Zhang Preprints on transpose free parallel ADI acceleration Updated Paper (Shapira) GAMM-Seminar Kiel on Concepts of Numerical Software C3 AD'98 [DD11] - Preliminary Notice 4th Numerical Methods Conference in Sofia, Bulgaria ------------------------------------------------------- Date: Tue, 30 Sep 1997 22:12:34 -0400 From: Craig Douglas Subject: MGNet anonymous ftp site moves The anonymous ftp site for MGNet has moved from Yale to the University of Kentucky, effective a few days ago. If you are mirroring MGNet through anonymous ftp, please change the address to ftp.ccs.uky.edu (ip address 128.163.209.106) The web pages for how to submit/retrieve files have changed to reflect this change (actually, the web pages have all changed for a variety of reasons). In particular, the incoming directory is not useful at Yale anymore. There is still an up to date copy at Yale, but it is not accessible until the old casper.cs.yale.edu is actually turned off. ------------------------------------------------------- Date: Wed, 3 Sep 1997 09:39:27 -0500 (CDT) From: JUN ZHANG Subject: Correction from Last Issue The preprint that was announced in MGNet should have had a title that reads BILUM: Block Versions of Multi-Eliminantion and Multi-Level ILU Preconditioner for General Sparse Linear Systems which is currently missing. Editor's Note: my fault, sorry... see http://www.cs.umn.edu/~jzhang ------------- for the preprint. ------------------------------------------------------- Date: Tue, 23 Sep 1997 22:51:21 -0500 (CDT) From: JUN ZHANG Subject: Two Papers from Jun Zhang On Convergence and Performance of Iterative Methods with Fourth-Order Compact Schemes (to appear in Numerical Methods for Partial Differential Equations) Jun Zhang Department of Mathematics, The George Washington University, Washington, DC 20052 ( Department of Computer Science and Engineering University of Minnesota, Minneapolis, MN 55455 ) December 13, 1996 ABSTRACT We study the convergence and performance of iterative methods with the fourth-order compact discretization schemes for the one and two dimensional convection-diffusion equations. For the one dimensional problem, we investigate the symmetrizability of the coefficient matrix and derive analytical formula for the spectral radius of the point Jacobi iteration matrix. For the two dimensional problem, we conduct Fourier analysis to determine the error reduction factors of several basic iterative methods and comment on their potential use as the smoothers for the multi-level methods. Finally, we perform numerical experiments to verify our Fourier analysis results. Editor's Note: in mgnet/papers/Zhang/fourier.ps.gz ------------- * * * * * * * * * * Residual Scaling Techniques in Multigrid, II: Practical Applications (to appear in Applied Mathematics and Computation) Jun Zhang Department of Mathematics, The George Washinton University Washington, DC 20052 ( Department of Computer Science and Engineering University of Minnesota, Minneapolis, MN 55455 ) July 1, 1996 ABSTRACT This paper focuses on practical applications of the multigrid residual scaling techniques and is the continuation of a companion paper: Residual scaling techniques in multigrid, I: equivalence proof. We discuss the computational issues of some residual scaling techniques which have been proved mathematically equivalent. A heuristic residual analysis technique, based on the geometry of the grid points and the relaxation pattern, is introduced to estimate the optimal residual scaling factor for a high-order multigrid method. We compare the performance of a typical pre-optimization (pre-acceleration) technique with a typical post-optimization (post-acceleration) technique and show that the pre-optimization is preferable in both convergence and efficiency. Our numerical results support theoretical conclusions made in the companion paper and demonstrate full advantage of the pre-optimization technique over the post-optimization technique. Editor's Note: in mgnet/papers/Zhang/scaling2.ps.gz ------------- Jun Zhang, Ph.D. * e-mail: jzhang@cs.umn.edu Department of Computer Science * Tel: (612) 626-0071 University of Minnesota * Fax: (612) 625-0572 Minneapolis, MN 55455, USA * http://www.cs.umn.edu/~jzhang ------------------------------------------------------- Date: Tue, 30 Sep 1997 22:12:34 -0400 From: Craig Douglas Subject: Preprints on transpose free parallel ADI acceleration Parameter Choices for ADI-like Methods on Parallel Computers S. Malhotra Scientific Computing Associates One Century Tower 265 Church Street New Haven, CT 06510-7010, USA C. C. Douglas Department of Mathematics University of Kentucky 715 Patterson Office Tower Lexington, KY 40506-0027, USA M. H. Schultz Department of Computer Science, Yale University P.O. Box 20-8285 New Haven, CT 06520-8285, USA Abstract Alternating direction iterative (ADI) methods do not usually work well on parallel computers due to having to do parallel rather than serial tridiagonal solves in all but one dimension. An ADI-like iteration is developed and analyzed which does not require parallel tridiagonal solves in any direction, has at least as good of a convergence rate as ADI, and has almost no communication when a small number of iterations are used. Acceleration parameters are investigated in order to reduce the number of of iterations to a small number. Numerical experiments on a network of workstations and a parallel computer are also included. Key words: alternating direction implicit methods, ADI, partial differential equations, iterative methods, parallel computing Editor's Note: in mgnet/papers/Malhotra-Douglas-Schultz/adiparam.ps.gz ------------- * * * * * * * * * * ``Transpose Free'' Alternating Direction Smoothers for Serial and Parallel Multigrid Methods C. C. Douglas Department of Mathematics University of Kentucky 715 Patterson Office Tower Lexington, KY 40506-0027, USA S. Malhotra Scientific Computing Associates One Century Tower 265 Church Street New Haven, CT 06510-7010, USA M. H. Schultz Department of Computer Science, Yale University P.O. Box 20-8285 New Haven, CT 06520-8285, USA Abstract Alternating Direction Implicit (ADI) methods are very good smoothers for multigrid. Like multigrid itself, ADI propagates information very quickly across a grid. On parallel processors, ADI is very inefficient due to the tridiagonal solves in each of the spatial directions. In one direction, the data typically resides in one processor. In the other directions, the data spans processor memories on distributed memory machines. In this paper, a ``transpose free'' variant of ADI is considered which eliminates the drawback of ADI on parallel processors. In addition, it is quite useful on serial computers. We provide convergence rates for a model problem and numerical results for variable coefficient elliptic problems in two and three dimensions. Key words: multigrid, alternating direction implicit methods, iterative methods, parallel computing, elliptic partial differential equations. Editor's Note: in mgnet/papers/Douglas-Malhotra-Schultz/adimg3d.ps.gz ------------- ------------------------------------------------------- Date: Wed, 24 Sep 1997 15:42:37 -0600 (MDT) From: Yair Shapira Subject: Updated Paper A Multi-Level Method for Sparse Linear Systems Editor's Note: in mgnet/papers/Shapira/amg.ps.gz ------------- ------------------------------------------------------- Date: Fri, 29 Aug 1997 15:11:31 +0200 (MET DST) From: Jens Burmeister Subject: GAMM-Seminar Kiel on Concepts of Numerical Software I would like to announce the 14th GAMM-Seminar Kiel on 'Concepts of Numerical Software' January 23rd to 25th, 1998, University of Kiel, Germany. Chairmanship: Wolfgang Hackbusch (Kiel), Gabriel Wittum (Stuttgart) Seminar topics are - Concepts of software development in general for . partial differential equations, . integral equations, . grid generation, . graphical postprocessing, etc. - Design and Modelling of numerical software, - Implementation aspects ; i.e. . parallelization and vectorization, . objectoriented realizations, etc. For more information please visit our homepage http://www.numerik.uni-kiel.de/gamm/ With best regards Jens Burmeister ------------------------------------------------------- Date: Thu, 25 Sep 97 19:02:44 -0300 From: Mauricio Vieira Kritz Subject: C3 AD'98 C3 AD'98 Colloquia on High Performance Scientific Computation Date: 17th to 22nd August 1998 Place: LNCC, Petropolis, Rio de Janeiro, Brazil Web: http://www.lncc.br/c3ad/98 ------------------------------------------------------- Date: Wed, 10 Sep 1997 16:27:26 +0100 From: Subject: [DD11] - Preliminary Notice Dear Colleague, This email is to draw your attention that the 11th International Conference on Domain Decomposition will be held at the University of Greenwich, UK during July 20 - 24, 1998. Please mark your diary. You may wish to send your full surface mailing address in order to receive further paper/flyers etc. Email address: dd11@gre.ac.uk A web page has also been set up, please check http://dd11.gre.ac.uk/ You will find call for papers on that web page very soon. Local Organising Committee University of Greenwich + Others ------------------------------------------------------- Date: Wed, 24 Sep 1997 17:37:23 +0300 Subject: 4th Numerical Methods Conference in Sofia, Bulgaria From: Panayot Vassilevski FIRST ANNOUNCEMENT and CALL for PAPERS 4th International Conference on Numerical Methods and Applications: NMA'98 August 19 - 23, 1998, Sofia, BULGARIA. ---------------------------------------------------------------------- The Institute of Mathematics and Informatics, Bulgarian Academy of Sciences, in cooperation with Central Laboratory for Parallel Processing, Bulgarian Academy of Sciences, Faculty of Mathematics and Informatics, University of Sofia, and Society for Industrial and Applied Mathematics (SIAM) is organizing the 4th International Conference on Numerical Methods and Applications. ---------------------------------------------------------------------- Honorary Chairman: Blagovest Sendov (Bulgaria) ---------------------------------------------------------------------- International Program Committee: Chairman: Michail Kaschiev (Bulgaria) H.Niederreiter (Austria), I.Dimov, S.Radev (Bulgaria), Z.Zlatev (Denmark), P.G.Ciarlet, B.Philippe (France), M.Griebel, W.Hackbusch, U.Jaekel, S.Rjasanow, M.Schaefer (Germany), O.Axelsson, P.Hemker, H.A.van der Vorst (The Netherlands), Z.Kamont, J.Popenda (Poland), B.N.Chetverushkin, R.P.Fedorenko, S.K.Godunov, S.P.Kurdyumov, Yu.P.Popov, I.V.Puzynin, A.A.Samarskii, P.N.Vabishchevich (Russia), V.Thomee (Sweden), L.Xanthis (UK), J.H.Bramble, R.E.Ewing, L.Perkins, M.F.Wheeler (USA), R.Lazarov (USA/Bulgaria), Yu.A.Kuznetsov (USA/Russia) ---------------------------------------------------------------------- Conference Topics: (1) Finite difference methods; (2) Finite element methods; (3) Finite volume methods; (4) Boundary element methods; (5) Monte Carlo methods; (6) Numerical linear algebra; (7) Parallel computing; (8) Numerical methods for non-linear problems; (9) Numerical methods for multiscale problems; (10) Multigrid and domain decomposition; (11) Computational fluid dynamics; (12) Mathematical modeling in structural mechanics; (13) Environmental modelling; (14) Engineering applications; (15) Minisymposia. ---------------------------------------------------------------------- List of key and invited lecturers, who already accepted invitation of the Org.Committee: O.Axelsson (The Netherlands), J.H.Bramble (USA), B.N.Chetverushkin (Russia), R.E.Ewing (USA), R.P.Fedorenko (Russia), S.K.Godunov (Russia), M.Griebel (Germany), P.Hemker (The Netherlands), U.Jaekel (Germany), Z.Kamont (Poland), S.P.Kurdyumov (Russia), Yu.A.Kuznetsov (USA/Russia), R.Lazarov (USA/Bulgaria), H.Niederreiter (Austria), L.Perkins (USA), B.Philippe (France), Yu.P.Popov (Russia), I.V.Puzynin (Russia), S.Rjasanow (Germany), A.A.Samarskii (Russia), M.Schaefer (Germany), V.Thomee (Sweden), P.N.Vabishchevich (Russia), H.A.van der Vorst (The Netherlands), M.F.Wheeler (USA), L.Xanthis (UK), Z.Zlatev (Denmark) ---------------------------------------------------------------------- Organizing Committee: Chairmen: Oleg Iliev and Panayot Vassilevski (Bulgaria) P.Binev, A.Karaivanova, M.Koleva, N.Kol'kovska, I.Lirkov, S.Margenov, S.Petrova, D.Vassileva, P.Yalamov (Bulgaria), M.Nikolova (The Netherlands), I.Bazhlekov, M.Neytcheva (The Netherlands/Bulgaria), A.Q.M.Khaliq, M.Paprzycki (USA), P.Entchev, L.Zikatanov (USA/Bulgaria) ====================================================================== Conference Presentations: The conference will include key and invited lectures, as well as contributed talks. Duration of the presentations will be tentatively 45, 35, and 25 min. A conference rule is that each participant will personally present no more then one talk. Presentation of posters will be considered, as well. The conference language will be English. ---------------------------------------------------------------------- CALL FOR ORGANIZING MINISYMPOSIA: To contribute a Minisymposium please provide the conference organizers with: a) minisymposium title, name and address of the organizer b) minisymposium abstract c) titles and authors of a minimum of 4 presentations d) abstracts of presentations (optional). Minisymposia proposals due: November 30, 1997 Minisymposia acceptance decision: December 31, 1997 ---------------------------------------------------------------------- CALL FOR PAPERS: People wishing to present a paper in a field related to the conference topics are invited to submit two hard copies of the paper, and its electronic version in LaTeX format by e-mail. The deadline is February 15, 1998. Papers should not exceed 12 pages for key and invited lectures, and 8 pages for contributed talks. Notification of acceptance and mandatory format of the final manuscript will be sent around May 1, 1998. ---------------------------------------------------------------------- Conference Proceedings: Proceedings (in a book form), of only refereed and presented at the conference papers, will be published. ---------------------------------------------------------------------- Abstracts: Abstracts (of a maximum 1 page) are required from all participants wishing to present a talk at the conference. Abstracts have to be send as ASCII files via e-mail. The deadline is February 15, 1998. ---------------------------------------------------------------------- Accommodation and Registration Fees: The living expenses (single room accommodation and full board) is currently estimated at the range of $250 for 5 days. Lower price accommodation is also planned to be available. The conference fee will cover publishing of the conference proceedings, conference booklet, excursion, conference dinner, reception, transportation from and to airport. Participants in the conference will be offered to buy the volume of the conference proceedings at a special price (to be specified later, subject to discussion with the Publisher). Conference fee is before June 15, 1998 after June 15, 1998 Non-students 180 US dollars 230 US dollars Students 100 US dollars 120 US dollars Accompanying person 80 US dollars 80 US dollars ---------------------------------------------------------------------- Deadlines: Submission of minisymposia proposals: November 30, 1997 Minisymposia acceptance decision: December 31, 1997 Submission of abstracts, papers and early registration forms: February 15, 1998 Notification of acceptance of full papers/presentations: May 01, 1998 Registration and submission of accommodation forms: June 15, 1998 ---------------------------------------------------------------------- Registration Form: An early on-line registration is available on either of our WWW-pages: http://banmatpc.math.acad.bg/~nma98/reg_form.html http://orca.st.usm.edu/marcin/mp/cfp/reg_form.html Another possibility to registrate is to fill-in and to send us via e-mail (or ordinary mail) the listed below registration form. ---------------------------------------------------------------------- For further information respond to the e-mail address: nma98@math.acad.bg, or check either of our WWW-pages: http://banmatpc.math.acad.bg/~nma98/ http://orca.st.usm.edu/marcin/mp/cfp/sofia.html The mailing address of the Organizing Committee can also be used: NMA'98, c/o Dr. Oleg Iliev Institute of Mathematics and Informatics Bulgarian Academy of Sciences Acad. G. Bonchev Str., Bl.8, 1113 Sofia, BULGARIA Fax-No. (++359 2) 971 36 49 E-mail communication is preferred. ---------------------------------------------------------------------- The next announcement will be distributed in December 1997. ---------------------------------------------------------------------- ====================================================================== Early Registration Form For nonstandard characters, please, use LaTeX notations. ====================================================================== Title ......... Name ......... First Name ......... Institution ......... Street/P.O.Box ......... Zip Code ......... City, State ......... Country ......... Fax ......... Telephone ......... E-mail ......... I wish to present: a talk yes/no a poster yes/no I am interested in having my paper published in the conference proceedings yes/no I declare that the paper is original and has not been submitted for publication elsewhere yes/no Title of the contributed talk ......... My talk is related to the topic (please, specify a number (1-15) from listed above conference topics) first choice ... second choice ... I am a student yes/no I shall be accompanied by ... (non-scientific) persons ====================================================================== ------------------------------ End of MGNet Digest **************************