Send mail to: mgnet@cs.yale.edu for the digests mgnet-requests@cs.yale.edu for comments or help Anonymous ftp repository: casper.cs.yale.edu (128.36.12.1) ftp.cerfacs.fr (138.63.200.33) World Wide Web: http://na.cs.yale.edu/mgnet/www/mgnet.html or http://www.cerfacs.fr/~douglas/mgnet.html Today's editor: Craig Douglas (douglas-craig@cs.yale.edu) Volume 6, Number 11 (approximately November 30, 1996) Today's topics: MGNet Web Page Reorganization Request for Information 3 new papers (Yavneh) New Paper (Shapira) 8th Copper Mountain Conference on Multigrid Methods Reminder Additions to mgnet.bib (Tai) Additions to mgnet.bib (Brenner) Another Faculty Position at the University of Kentucky ------------------------------------------------------- Date: Sat, 30 Nov 1996 07:58:41 -0500 (EST) From: Craig Douglas Subject: MGNet Web Page Reorganization Over the past month, many of the web pages for MGNet have undergone an extensive set of updates. This will continue over the next 2 months as I find time. A professional art designer offered a number of specific suggestions. It is hopefully now much easier to find information and visually more appealing. It is very easy to tell which parts have been changed and which parts have yet to be updated. The principal pages have all undergone revision. Suggestions are welcome. One of the changes that will go into effect on December 3 is that there will be a "link of the week" to a web site that I think is of interest to the readers of this digest. If you want to see what has been picked, you have to visit MGNet's main web page and click on the link. It will usually change on Monday thereafter. If you think that your personal or group web page is noteworthy, please send me the URL by e-mail. Chris Johnson of the University of Utah was the first to report a problems with the new pages. It turned out that Netscape's browser handles JavaScript a little differently than is published. All of the effected pages have been fixed to get around this anomoly. My pages caused a core dump on his SGI. Please contact me if you have a problem. If you have not already done so, this is a good time to upgrade to version 3+ of either Netscape's or Microsoft's browsers. Also, the pages look better on color displays if you go into the general preferences/appearances options menu and turn off automatic underlining of links. ------------------------------------------------------- Date: Sat, 30 Nov 1996 08:10:12 -0500 (EST) From: Craig Douglas Subject: Request for Information Essentially all of the preprints and virtual proceedings' papers on MGNet are stored as gzipped PostScript files. For anyone using a UNIX machine to view these papers with netscape, it is easy to set up a .mailcap file to automatically gunzip a paper and start a viewer like ghostview. A number of people have recently asked how to do this when using a Windows 95 machine or a Mac. I will admit to virtually never using either (many of you know that I use Linux on my PC's). If you have this problem solved, could you please e-mail me your solution? It does not really matter if I get multiple solutions, as long as I can post ones that work for Windows and Macs. Thanks in advance... Craig ------------------------------------------------------- Date: Wed, 27 Nov 1996 11:16:18 +0200 From: Subject: 3 new papers (Yavneh) I just put three papers in the "incoming" directory, two in subdirectory Yavneh, and one in Yavneh-Venner-Brandt. The papers are in gzipped postscript and the abstracts in ascii. Please let me know if anything else is needed before these can be added to my existing contributions. Thanks! Irad Yavneh. Coarse-Grid Correction for Nonelliptic and Singular Perturbation Problems Irad Yavneh Department of Computer Science Technion---Israel Institute of Technology Haifa 32000, Israel October 1996 The suitability of coarse-grid correction operators for multigrid solution of discretized nonelliptic partial differential equations is studied. It is found that the requirements for the orders of intergrid transfers and the order of approximation of the coarse-grid operators differ in an important way from the well-known ``rules'' pertaining to elliptic operators. Both Galerkin coarsening and coarsening schemes based on the differential operator are examined, and new coarse-grid correction strategies are suggested in light of this analysis. Editor's Note: in mgnet/papers/Yavneh/cgc.ps.gz ------------- Multigrid Smoothing for Symmetric Nine-Point Stencils Irad Yavneh and Elena Olvovsky Department of Computer Science Technion---Israel Institute of Technology Haifa 32000, Israel November 1996 Analytical formulae are obtained for the smoothing factors yielded by damped Jacobi relaxation and by red-black relaxation applied to symmetric nine-point stencil discretizations of elliptic partial differential operators in 2D. The results include point and line relaxation and full and partial coarsening. Several unusual results are implied by the formulae. Numerical results of multigrid cycles match the analytical predictions well. Editor's Note: in mgnet/papers/Yavneh/ninepoint.ps.gz ------------- Fast Multigrid Solution of the Advection Problem with Closed Characteristics I. Yavneh Technion---Israel Institute of Technology Haifa, Israel C.H. Venner University of Twente, Enschede, The Netherlands A. Brandt Weizmann Institute of Science, Rehovot, Israel September 1995 The numerical solution of the advection-diffusion problem in the inviscid limit with closed characteristics is studied as a prelude to an efficient high Reynolds-number flow solver. It is demonstrated by a heuristic analysis and numerical calculations that using upstream discretization with downstream relaxation-ordering in a multigrid cycle with appropriate residual weighting leads to an efficient solution process. Upstream finite-difference approximations to the advection operator are derived whose truncation terms approximate ``physical'' (Laplacian) viscosity, thus avoiding spurious solutions to the homogeneous problem when the artificial diffusivity dominates the physical viscosity. Editor's Note: in mgnet/papers/Yavneh-Venner-Brandt/recirculating.ps.gz ------------- ------------------------------------------------------- Date: Mon, 2 Dec 1996 15:28:56 -0700 (MST) From: Yair Shapira Subject: New Paper (Shapira) Multigrid for Locally Refined Meshes Yair Shapira Computer Science Department, Technion, Haifa 32000, Israel Now at Los Alamos National Laboratory MS B-256, Los Alamos NM 87545 e-mail: yairs@lanl.gov. Abstract A two-level method for the solution of finite element schemes on locally refined meshes is introduced. The upper bound on the condition number implies, in some cases, mesh-independent convergence, as is verified numerically for a diffusion problem with discontinuous coefficients. The discontinuity curves are not necessarily aligned with the coarse mesh; indeed, numerical applications with ten levels of local refinement yield a fast convergence for the corresponding ten-level multigrid V-cycle, even when the discontinuities are invisible on most of the coarse meshes. Editor's Note: in mgnet/papers/Shapira/refine.ps.gz ------------- ------------------------------------------------------- Date: Fri, 29 Nov 1996 20:41:25 -0700 (MST) From: Steve McCormick Subject: 8th Copper Mountain Conference on Multigrid Methods Reminder EIGHTH COPPER MOUNTAIN CONFERENCE ON MULTIGRID METHODS Copper Mountain, Colorado, USA APRIL 6-11, 1997 DEADLINE APPROACHING FOR SUBMISSION OF PAPERS FOR STUDENT SUPPORT: Travel and lodging assistance will be awarded to student authors judged to have the best research papers. Papers containing original research due mainly to the student must be received before Dec. 15, 1995. They must be singly authored and may be no more than 10 pages in length. Sending only an abstract is unacceptable. Authors will be expected to present their paper in one of the regular conference sessions. Student papers should be submitted as ps files by e-mail to cm97@boulder.colorado.edu. If this is not possible, a hard copy of the paper may be submitted by regular post to: CMCMM97 Applied Math Campus Box 526 University of Colorado Boulder, CO 80309-0526 OTHER IMPORTANT DEADLINES: Author Abstracts January 15, 1997 Papers for NASA Proceedings March 15, 1997 Guaranteed Availibility of Lodging February 6, 1997 Early Registration February 6, 1997 FURTHER INFORMATION: For information such as registration, author instructions, and lodging arrangements (including a lodging bulletin board), please access: http://amath-www.colorado.edu:80/appm/faculty/copper/. You may also contact us by email at cm97@boulder.colorado.edu. Steve McCormick: Appl. Math, C.B. 526, U. of CO, Boulder, CO 80309-0526 (303)492-0662 stevem@newton.colorado.edu ftp://amath.colorado.edu/pub -4066 fax http://amath-www.colorado.edu/appm/faculty/stevem/ ------------------------------------------------------- Date: Fri, 1 Nov 96 15:13:03 MET From: Subject: Additions to mgnet.bib (Tai) Could you please add the following of my works into you mgnet.bib file? Sincerely Tai. @article{no.169+, author = "Xue-Cheng Tai and P. Neittaanmaki", title = "A parallel finite element splitting-up methods for parabolic problem", journal = "Numerical Methods for Partial Differential Equation", year = "1991", volume = "7", pages = "209--225", } @article{no.170+, author = "T. Lu and P. Neittaanmaki and X-C Tai", title = "A parallel splitting up method and its application to Navier-Stoke equations", journal = "Applied Mathematics Letters", year = "1991", volume = "4", pages = "25--29", } @article{no.171+, author = "T. Lu and P. Neittaanmaki and X-C Tai", title = "A parallel splitting up method for partial differential equations and its application to Navier-Stokes equations", journal = "RAIRO Math. Model. and Numer. Anal.", year = "1992", volume = "26", pages = "673--708", } @article{no.172+, author = "Xue-Cheng Tai and Pekka Neittaanmaki", title = "Error estimates for numerical identification of distributed parameters", journal = "J. Comp. Math.", year = "1992", volume = "supplementary issue", pages = "66-78", } @article{no.173+, author = "Xue-Cheng Tai", title = "Global extrapolation with a parallel splitting method", journal = "Numerical Algorithms", year = "1992", volume = "3", pages ="427--440", } @article{no.174+, author = "X.-C. Tai and T. Karkainen", title = "Identification of a nonlinear parameter in a parabolic equation from a linear equation", journal = "Comp. Appl. Mat.", year = "1995", volume = "14", pages = "157--184", } @article{no.175+, author = "Xue-Cheng Tai", title = "Parallel function and space decomposition methods -- {Part I}. Function decomposition", journal = "Beijing Mathematics", year = "1995", volume = "1, part 2", pages = "104--134", } @article{no.176+, author = "Xue-Cheng Tai", title = "Parallel function and space decomposition methods -- {Part II}. Space decomposition", journal = "Beijing Mathematics", year = "1995", volume = "1, part 2", pages = "135--152", } @article{no.177+, author = "K. Kunisch and X.-C. Tai", title = "Sequential and parallel splitting methods for bilinear control problems in Hilbert spaces", journal = "SIAM J. Numer. Anal.", year = "1997", } @inproceedings{no.178+, author = "Xue-Cheng Tai and Pekka Neittaanmaki", title = "A {FE-splitting-up} method and its application to distributed parameter identification of parabolic type", booktitle= "Approximation, Optimisation and Computing. Theory and Applications", editor = "A. G. Law and C. L. Wang", year = "1990", pages = "185--188", publisher = "Elsevier", } @inproceedings{no.179+, author = "Xue-Cheng Tai and Pekka Neittaanmaki", title = "A linear approach for the nonlinear distributed parameter identification", booktitle = "Numerical methods for free boundary problems", year = "1991", volume = "99", editor = "P. Neittaanmaki", pages = "401-411", publisher = "Birkhauser Verlag Basel", series = "International series of numerical mathematics", } @inproceedings{no.180+, author = "Xue-Cheng Tai and Pekka Neittaanmaki", title = "On the numerical solution of the distributed parameter parameter identification problem", booktitle = "Control and estimation of distributed parameter systems", year = "1991", volume = "100", pages = "317--329", publisher = "Birkhauser Verlag Basel", series = "International series of numerical mathematics", } @inproceedings{no.181+, author = "Xue-Cheng Tai", title = "Domain decomposition for linear and nonlinear elliptic problems via function or space decomposition", booktitle = "Domain decomposition methods in scientific and engineering computing", year = "1995", editor = "D. Keyes and J. Xu", pages = "355--360", publisher = "American Mathematical Society", series = "Proc. of the 7th international conference on domain decomposition, Penn. State University, 1993", } @inproceedings{no.182+, author = "Xue-Cheng Tai", title = "Parallel function and space decomposition methods", booktitle = "The Finite element Method: Fifty years of the Courant Element", year = "1994", volume = "164", editor = "P. Neittaanmaki", pages = "421--432", publisher = "Marcel Dekker", series = "Lecture notes in pure and applied mathematics", } Dr Xue-Cheng Tai Tel. 47 55 58 4868 (office), Bergen University, Tel. 47 55 34 7356 (home), Mathematics Department, Fax. 47 55 58 4885, Alleg. 55, 5007, Bergen, Norway. www: http://www.mi.uib.no/~tai Editor's Note: Now in mgnet/bib/mgnet.bib. ------------- ------------------------------------------------------- Date: Mon, 2 Dec 1996 14:20:46 -0500 From: Susanne Brenner Subject: Additions to mgnet.bib (Brenner) @book{PGrisvard_1992a, author = "P. Grisvard", title = "Singularities in Boundary Value Problems", series = "Research Notes in Applied Mathematics", volume = "22", publisher = "Masson", address = "Paris", year = "1992", } @book{EGDyakonov_1996a, author = "Eugene G. D'yakonov", title = "Optimization in Solving Elliptic Problems", series = "", volume = "", publisher = "CRC Press, Inc.", address = "Boca Raton", year = "1996", } Editor's Note: Will be in mgnet/bib/mgnet.bib shortly. ------------- ------------------------------------------------------- Date: Sat, 30 Nov 1996 10:11:12 -0500 (EST) From: Craig Douglas Subject: Another Faculty Position at the University of Kentucky While I was visiting Lexington recently, I discovered that the computer science department is trying to hire a faculty member in scientific computing. This is in addition to the math department position that was listed here last month. If you are interested in the details, look at http://www.cs.uky.edu/positions.html for the real details. (Note: I am just passing this information along.) If a reader of this mailing list applies for either the math or the computer science positions, would you drop me a one line note, please? Thanks. ------------------------------ End of MGNet Digest **************************