Send mail to: mgnet@cs.yale.edu for the digests or bakeoff
mgnet-requests@cs.yale.edu for comments or help
Current editor: Craig Douglas douglas-craig@cs.yale.edu
Anonymous ftp repository: ftp.ccs.uky.edu (128.163.209.106)
World Wide Web: http://www.mgnet.org or
http://casper.cs.yale.edu/mgnet/www/mgnet.html or
http://www.cerfacs.fr/~douglas/mgnet.html or
http://phase.etl.go.jp/mgnet or
http://www.nchc.gov.tw/RESEARCH/Math/mgnet/www/mgnet.html
Today's editor: Craig Douglas (douglas-craig@cs.yale.edu)
Volume 9, Number 2 (approximately February 28, 1999)
Today's topics:
Important Date
Microsoft Word Documents
EMG'99 home page
Copper Mountain Preliminary Program Online
PLTMG8.1 on MGNet
MGCG
Mathematical/Computational Techniques for Multilevel Adaptive Methods
Paper on Global Hall Conductor in the Earth's Ionosphere
Viscous Incompressible/Low-Mach-Number Flows on High Aspect Ratio Grids
Paper on Stress Concentration Problems
4 Copper Mountain Papers
Two prints from Jun Zhang
Teigland Bibliography Update
International Conference on Preconditioning Techniques
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Date: Sun, 28 Feb 1999 11:23:22 +0500
From: Craig C. Douglas
Subject: Important Date
March 11 Hotel reservations for the Copper Mountain Conference on Multigrid
Methods. See http://www.mgnet.org/mgnet-conferences.html for a
link to the conference.
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Date: Sun, 28 Feb 1999 15:42:55 +0500
From: Craig C. Douglas
Subject: Microsoft Word Documents
I am receiving more and more preprints or papers for virtual proceeding papers
produced using Microsoft Word. Some I can look at on my laptop and some I
cannot. There are several common themes that will make submission much
quicker.
If your document uses special fonts, it will probably not be renderable by the
vast majority of MGNet readers. Also, one of the options in Word2000 is to
save files in HTML format in a manner that is supposed to be lossless. The
font problem still exists in this case.
If you use a different separator than the default , (Windows), you might save
the file once with the default separator.
A quick fix is to submit either an Adobe PDF file as well or to use "print to
file" using the Apple Laserwriter printer driver (the ancient printer, not a
PostScript level 3 driver). The PDF file will be closer to what your document
looks like under Word.
-------------------------------------------------------
Date: Tue, 09 Feb 1999 09:36:17 +0100
From: Kris Riemslagh
Subject: EMG'99 home page
We forgot to include a reference to our home-page in the call for papers of
the EMG 99. Please include the following link at your EMG99 page:
http://allserv.rug.ac.be/~edick/emg/
Dr. ir. Kris Riemslagh
Universiteit Gent
Vakgroep Werktuigkunde en Warmtetechniek
Dept. Mechanical and Thermal Engineering
Sint Pietersnieuwstraat 41
B-9000 GENT, Belgie
Tel: +32/9/264.33.13; Fax: +32/9/264.35.86
E-mail: Kris.Riemslagh@rug.ac.be
-------------------------------------------------------
Date: Sun, 28 Feb 1999 11:25:21 +0500
From: Craig C. Douglas
Subject: Copper Mountain Preliminary Program Online
The Copper Mountain preliminary program (still tentative) is at
http://amath-www.colorado.edu/appm/faculty/copper/1999/program.html
-------------------------------------------------------
Date: Mon, 08 Feb 1999 10:26:20 -0800
From: "Randolph E. Bank"
Subject: PLTMG8.1 on MGNet
I would like to update pltmg8.0 with pltmg8.1. Functionally, this version is
identical to pltmg8.0. A few bugs have been fixed, and the driver program
routines have been reworked a bit. In particular, xgraph.c should be more
compatible with default linux X-windows configurations.
Randolph E. Bank Tel: (619) 534-4204
Department of Mathematics Fax: (619) 534-5273
University of California, San Diego Email: rbank@ucsd.edu
La Jolla, CA 92093-0112 http://sdna3.ucsd.edu/~reb
Editor's Note: See http://www.mgnet.org/mgnet-codes-pltmg.html
-------------
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Date: Mon, 01 Mar 1999 12:20:48 -0500
From: "E. Bruce Pitman"
Subject: MGCG
I am looking for papers and any code that might be available, using multigrid
as a preconditioner to a CG solver. Any pointers will be greatly appreciated.
E. Bruce Pitman
Professor
Director of Graduate Studies
Department of Mathematics
106 Diefendorf Hall
State University of New York
Buffalo, NY 14214-3093
(716)829-2144 voice (716)829-2299 fax
pitman@galileo.math.buffalo.edu Center for Computational Research
http://www.math.buffalo.edu/~pitman http://www.ccr.buffalo.edu
-------------------------------------------------------
Date: Mon, 1 Mar 1999 12:41:14
From:
Subject: Mathematical/Computational Techniques for Multilevel Adaptive Methods
Je suis etudiant tchadien. Le tchad est un pays africain. Je prepare une
these sur "mathematical and computational techniques for multilevel adaptive
methods". Je voudrais avoir une documentation complete en anglais sur le
sujet. Je veux aussi les travaux recents sur les multigrilles et les
multiniveaux adaptative. mon adresse: Djibet M'bainguesse enseignant et
chercheur faculte des sciences exactes et appliquees
Universite du Tchad
bp1027 N'djamena Tchad.
-------------------------------------------------------
Date: Fri, 12 Feb 1999 10:43:34 +0700
From: "Valeri Denissenko"
Subject: Paper on Global Hall Conductor in the Earth's Ionosphere
Multigrid Method for a Global Hall Conductor in the Earth's Ionosphere
Valeri V. Denissenko
Institute of Computational Modelling
Krasnoyarsk, 660036, Russia
Abstract
Since conductivity is an asymmetric tensor in the ionosphere the elliptical
operators of the boundary value problems are not selfadjoint. To overcome
difficulties that arise in numerical solution of problems with not selfadjoint
operators it is proposed to replace the traditional statements with new ones
in which the operators are symmetrical and positive definite. A narrow
boundary strip in that the coefficients are huge in comparing with those in
the interior of the domain is separated with a special boundary condition.
The finite element equations are obtained as a conditions of a minimum of the
energy functional with a special set of parameters to approximate the main
boundary conditions. Positive definiteness of the matrix is proved. A
multigrid method that is used to solve these equations and a numerical example
are presented.
Key words. gyrotropic transfer, Hall conductivity, symmetrization, elliptic
equation, variational principle, finite elements, multigrid method
AMS subject classifications. Primary 65N30, 35J50; Secondary 78A25
Editor's Note: See http://www.mgnet.org/mgnet-parmgm98.html or
------------- http://www.mgnet.org/Conferences/ParMGM98/Papers/denissenko.ps.gz
-------------------------------------------------------
Date: Thu, 25 Feb 1999 14:56:23 +0100
From: Jan Vierendeels
Subject: Viscous Incompressible/Low-Mach-Number Flows on High Aspect Ratio Grids
A Multigrid Semi-Implicit Line Method for Viscous Incompressible
and Low-Mach-Number Flows on High Aspect Ratio Grids
Jan Vierendeels, Kris Riemslagh, and Erik Dick
Department of Mechanical and Thermal Engineering
Universiteit Gent, Belgium
Abstract
Discretization of viscous incompressible and viscous low-Mach-number flows
often leads to a system of equations, which is very difficult to solve. There
are two reasons. First, the use of high aspect ratio grids results in a very
numerically anisotropic behaviour of the diffusive and acoustic terms and
second, in low-Mach-number flow, the ratio of the convective and acoustic
eigenvalues of the inviscid system becomes very high.
We implemented an AUSM based discretization method, using an explicit
third-order discretization for the convective part, a line-implicit central
discretization for the acoustic part and for the diffusive part. The lines
are chosen in the direction of the gridpoints with shortest connection. The
preconditioned semi-implicit line method is used in multistage form because of
the explicit third-order discretization of the convective part. Multigrid is
used as acceleration technique.
It is shown that the convergence is very good, independent of grid aspect
ratio and Mach number.
Editor's Note: See http://www.mgnet.org/mgnet-parmgm98.html or
------------- http://www.mgnet.org/Conferences/ParMGM98/Papers/vierendeels.ps.gz
-------------------------------------------------------
Date: Mon, 1 Mar 1999 01:37:23 -0800 (PST)
From: Alexander Trofimov
Subject: Paper on Stress Concentration Problems
Multigrid Methods for Stress Concentration Problems
Alexander V. Trofimov
Dnepropetrovsk State University, Ukraine
Abstract
Some aspects of the Multigrid Methods implementation to stress concentration
problems are discussed. Convenient variational formulations for such problems
are proposed. Computational aspects of Richardson's extrapolation methods
implementation and nonlinear iterations are investigated. The efficiency of
multigrid and some other widespread algorithms is compared.
Warning: The correct drawing of mathematical symbols depends on the Windows
tuning parameter "list separator." You have to choose
Control Panel -> Regional Settings -> Numbers -> List separator
It must be set to ";" (semicolon)
Editor's Note: See http://www.mgnet.org/mgnet-parmgm98.html or
------------- http://www.mgnet.org/Conferences/ParMGM98/Papers/trofimov.doc
-------------------------------------------------------
Date: Sun, 28 Feb 1999 16:18:20 +0500
From: Craig C. Douglas
Subject: 4 Copper Mountain Papers
The Application of the Multigrid Method in a Nonhydrostatic Atmospheric Model
Shu-Hua Chen
Department of Earth and Atmospheric Sciences
Purdue University
West Lafayette, IN 47907, USA
Abstract
A nonhydrostatic atmospheric model is developed. The use of the Semi-implicit
scheme in this model has relaxed the constraint of exceedingly small time
step, but it generates a huge sparse matrix (400,000 x 400,000) of the
Elliptic Partial Differential Equations (EPDEs). This study attempts to apply
the Multigrid method to solve these EPDEs and to address the performance and
efflciency of the Multigrid method. Two experiments are examined. The model
results are in good agreement with those in historical papers and the
analytical solution. Furthermore, the Multigrid solver, mud3cr, applied in
this model is very efflcient. These indicate the success of the Muitigrid
method applied to nonhydrostatic atmospheric models.
Editor's Note: See http://www.mgnet.org/mgnet-ccmm99.html or
------------- http://www.mgnet.org/Conferences/CopperMtn99/Papers/chen.ps.gz
* * * * *
Cache Based Multigrid on Unstructured Grids
Jonathan Hu
Universityof Kentucky
Departmentof Mathematics
715 Patterson Offlce Tower
Lexington, KY 40506-0027, USA
Abstract
High speed cache memory is commonly used to address the disparity between the
speed of a computer's central processing unitand the computer's main memory
speed. It is advantageous to maximize the amount of time that data spends in
cache. Tiling is a software technique which is often used to do just this.
Tiling is not able, however, to handle dynamically changing data structures,
such as are encountered in adaptively chosen, unstructured grids. We develop
a variant of the Gauss-Seidel method which keeps data in cache memory for much
longer than non-cache implementations. As a result, our method is
significantly faster than non-cache implementations. Examples from the
structured grid case demonstrate the benefits of such a variant and provide
motiv ation for the more difflcult unstructured grid case. For this case, an
O(n) algorithm is introduced that divides nodes into blocks whichf it into
cache. This leads to a new ordering which allows significantly more
Gauss-Seidel updates and residual calculation to be done in cache than in
standard implementations. Numerical experiments demonstrate the speedups
possible with the cache aware Gauss-Seidel method and with a multigrid V cycle
using the cache aware method.
Editor's Note: See http://www.mgnet.org/mgnet-ccmm99.html or
------------- http://www.mgnet.org/Conferences/CopperMtn99/Papers/hu.ps.gz
* * * * *
A Multigrid Strategy for Accelerating Steady-State Computations of Waves
Propagating with Curvature Dependent Speeds
Jonathan Rochez
Department of Applied Science
University of California, Davis
Davis, CA, USA
Abstract
A multigrid strategy is developed for accelerating the steady state
computations of waves propagating with curvature dependent speeds. This will
allow the rapid computation of a ``burn table.'' In a high explosive material,
the creation of a burn table will allow the elimination of solving chemical
reaction ODEs and feed in source terms to the reactive flow equations for
solution of the system of ignition of the high explosive material. Standard
iterative methods show a quick reduction of the residual followed by a slow
final convergence to the solution at high iterations. Such systems are
excellent choices for the use of multigrid methods to speed up convergence,
even on a nonlinear system such as this. Numerical steady-state solutions to
the eikonal equationon on a rectangular grid are conducted. Results are
presented for a square grid in 2D and a cubic grid in 3D using a Runge-Kutta
time iteration for the smoothing operator until steady-state is reached.
Editor's Note: See http://www.mgnet.org/mgnet-ccmm99.html or
------------- http://www.mgnet.org/Conferences/CopperMtn99/Papers/rochez.ps.gz
* * * * *
Fourier Analysis of GMRES(m) Preconditioned by Multigrid
R. Wienands
GMD
Institute for Algorithms and Scientific Computing
D-53754 St. Augustin, Germany
Abstract
This paper deals with convergence estimations of a preconditioned GMRES(m)
method, where multigrid is used as the preconditioner. Fourier analysis is a
well-known useful tool in the multigrid community for the prediction of
two-grid convergence rates. This analysis is generalized to the situation
where multigrid is a preconditioner.
Editor's Note: See http://www.mgnet.org/mgnet-ccmm99.html or
------------- http://www.mgnet.org/Conferences/CopperMtn99/Papers/wienands.ps.gz
-------------------------------------------------------
Date: Sun, 28 Feb 1999 11:55:54 -0500 (EST)
From: Jun Zhang
Subject: Two prints from Jun Zhang
A Grid Based Multilevel Incomplete LU Factorization
Preconditioning Technique for General Sparse Matrices
Jun Zhang
Department of Computer Science, University of Kentucky
773 Anderson Hall, Lexington, KY 40506--0046, USA
ABSTRACT
We design a grid based multilevel incomplete LU preconditioner (GILUM) for
solving general sparse matrices. This preconditioner combines a high accuracy
ILU factorization with an algebraic multilevel recursive reduction. The GILUM
preconditioner is a compliment to the domain based multilevel block ILUT
preconditioner. A major difference between these two preconditioners is the
way that the coarse level nodes are chosen. In this sense the approach of
GILUM is analogous to that of algebraic multigrid method. However, the GILUM
construction is completely different from the algebraic multigrid
construction. A partial ILUT factorization is applied to the reordered matrix
and the coarse level system is obtained implicitly. The incomplete
factorization process is repeated with the coarse level systems recursively.
The GILUM approach avoids some controversial issues in algebraic multigrid
method such as how to construct the interlevel transfer operators and how to
compute the coarse level operator. Numerical experiments are conducted to
compare GILUM with other ILU preconditioners.
* * * * *
RILUM: A General Framework for Robust Multilevel
Recursive Incomplete LU Preconditioning Techniques
Jun Zhang
Department of Computer Science, University of Kentucky
773 Anderson Hall, Lexington, KY 40506--0046, USA
ABSTRACT
We introduce a general framework for constructing multilevel recursive
incomplete LU preconditioning techniques (RILUM) for solving general sparse
matrices. This technique is based on a recursive two by two block incomplete
LU factorization on the coefficient matrix. The coarse level system is
constructed as an (approximate) Schur complement. A dynamic preconditioner is
obtained by solving the Schur complement matrix approximately. The novelty of
the proposed techniques is to solve the Schur complement matrix by a
preconditioned Krylov subspace method. The very preconditioner for this
secondary iteration is constructed by considering the Schur complement matrix
as a general sparse matrix and by applying to it the block ILU factorization
process that was applied to the original matrix. This recursive procedure
continues for a few times and results in a multilevel preconditioner.
Different implementation strategies are discussed. We conduct numerical
experiments with two particular RILUM implementations to show the performance
of the proposed techniques and to demonstrate grid independent convergence
rates of RILUM for solving certain problems.
Editor's Note: See http://www.cs.uky.edu/~jzhang
-------------
-------------------------------------------------------
Date: Mon, 15 Feb 1999 16:05:21 +0100
From: Rune Teigland
Subject: Teigland Bibliography Update
Please find attached a listing of my contributions related to multigrid/domain
decomposition.
@phdthesis{
author = "Teigland, R.",
title = "On Multilevel Methods for Numerical Reservoir Simulation,
Report No. 92, October 1991, ISSN 0084-778x",
school = "University of Bergen, Norway",
year = "1991",
}
@inproceedings{
author = "Teigland R. and Fladmark G.E.",
title = "Cell-centered Multilevel Methods in
Reservoir Simulation",
booktitle = "International Series of Numerical Mathematics",
volume = "98",
year = "1991",
pages = "365-376",
publisher = "Birkhauser Verlag, Basel."
}
@article{
author = "Ersland B.G. and Teigland R.",
title = "Comparison of Two Cell-Centered Multigrid
Schemes for Problems with Discontinuous Coefficients",
journal = "Numer. Meth. for PDE",
volume = "9",
year = "1993",
pages = "265-283",
}
@inproceedings{
author = "Teigland, R.",
title = "An Additive {S}chwarz Procedure for Complex Flows",
editor = "Paul A. Thibault and Denis M. Bergeron",
booktitle = "Proc. Third Annual Conference of the CFD Society of Canada",
year = 1995,
pages = "145-152"
}
@inproceedings{
author = "Gjesdal T., Lossius M.E.H., Teigland R.",
title = "Multigrid Solution of
Incompressible Flow Using Pressure Correction Smoothers",
editor = "Paul A. Thibault and Denis M. Bergeron",
booktitle = "Proc. Third Annual Conference of the CFD Society of Canada",
year = 1995,
pages = "145-152"
}
@article{
author = "Teigland R.",
title = "On some variational acceleration techniques and related
methods for local refinement",
journal = "Int. J. Numer. Meth. Fluids",
volume = "28",
year = "1998",
pages = "945-960",
}
@inproceedings{
author = "Teigland, R.",
title = "A Domain Decomposition Strategy for Simulation of Complex
Industrial Fluid Flows",
booktitle = "Proc. Ninth Int. Conf.
on Domain Decomposition",
editors = "P.E. Bj{\o}rstad, M.S. Espedal, and D.E. Keyes",
publisher = "Domain Decomposition Press,
Bergen, Norway",
year = "1998",
pages = "817-825",
}
Rune Teigland | Tel:+47 55 99 68 97 (office)| |
Norsk Hydro | Tel:+47 55 95 32 35 (home) | (((( |
Research Center | E-mail: |(oooo)|
N-5020 Bergen, Norway | Rune.Teigland@nho.hydro.com | |
Editor's Note: These will be integrated into the bibliography. See
------------- http://www.mgnet.org/mgnet-bib.html
-------------------------------------------------------
Date: Feb 1999
From: Yousef Saad
Subject: International Conference on Preconditioning Techniques
SUBJECT: Intl. Conf. on preconditioning techniques
FROM: Yousef Saad - U. of Minnesota
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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:
* Deadline for submitting extended abstracts has been extended to
March 5th, 1999. 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.
Editor's Note: Deadline extended to MONDAY, MARCH 8 (so write fast :-)
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End of MGNet Digest
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