Send mail to: mgnet@cs.yale.edu for the digests or bakeoff
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Anonymous ftp repository: www.mgnet.org (128.163.209.19)
Current editor: Craig Douglas douglas-craig@cs.yale.edu
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http://www.nchc.gov.tw/RESEARCH/Math/mgnet/www/mgnet.html
Today's editor: Craig Douglas (douglas-craig@cs.yale.edu)
Volume 10, Number 4 (approximately April 30, 2000)
Today's topics:
Next Issue
Interactive Numerical Examples in ETNA
Job in Numerical Analysis
Two Open Positions at the University of Zurich
Copper Mountain 2000 Paper (Freund)
Copper Mountain 2000 paper (Notay)
Copper Mountain Conference on Iterative Methods: Talks
-------------------------------------------------------
Date: Sat, 13 May 2000 09:56:28 +0500
From: Craig Douglas
Subject: Next Issue
The next issue needs to come out on around June 1. Please contribute items
now or as soon as possible. I will be maintaining an active new newsletter on
the web as soon as material is available instead of waiting until the issue
needs to go out.
-------------------------------------------------------
Date: Thu, 6 Apr 2000 10:51:14 -0400 (EDT)
From: Lothar Reichel
Subject: Interactive Numerical Examples in ETNA
Many papers in computational mathematics contain numerical examples that
illustrate the theory discussed, or the virtues or shortcomings of numerical
methods. The examples, in general, depend on certain parameters, whose values
are chosen by the author of the paper. A reader may be interested in studying
the examples for other parameter values, but typically this is not
straightforward. Computer programs may have to be written or requested from
the author of the paper.
The Electronic Transactions on Numerical Analysis (ETNA) makes it possible to
publish interactive examples that allow readers to vary parameter values.
Presently, two papers
J. Baglama, D. Calvetti and L. Reichel, Fast Leja points,
ETNA 7 (1998), pp. 124-140,
R. S. Varga and A. Krautstengl, On Gersgorin-type problems
and ovals of Cassini, ETNA 8 (1999), pp. 15-20,
illustrate this feature. Click on the ``interactive supplement'' for these
papers for a demonstration.
Authors of papers accepted for publication in ETNA are encouraged to supply
interactive examples. The ETNA staff will assist with the design and Java
programming of the examples.
ETNA is available at
http://etna.mcs.kent.edu
and at mirror sites. In addition volumes 1-10 of ETNA are available on a new
CDROM. The ETNA CDROM contains papers published in ETNA 1993-2000,
interactive examples, a search engine and web browsers. A limited number of
CDROMs are available for $10 each. Please send e-mail to etna@mcs.kent.edu if
you would like your own portable copy of ETNA on a CDROM.
-------------------------------------------------------
Date: Thu, 13 Apr 2000 12:00:26 +0100 (BST)
From: Iain Duff
Subject: Job in Numerical Analysis
RESEARCH POSITION IN NUMERICAL ANALYSIS
Rutherford Appleton Laboratory, Oxfordshire
Fixed Term (4 years with possible extension)
A research position is available within the Numerical Analysis Group at the
Rutherford Appleton Laboratory of the Central Laboratory of the Research
Councils. Duties will involve performing independent but relevant research,
with the goal of publication in the open literature and presenting the results
at national and international conferences. Duties will include the production
of high-quality numerical software connected with this research and the
promotion of the Group's activities within the UK academic community. There
will also be the opportunity to lecture in occasional Laboratory courses on
numerical analysis and computing areas.
The ideal candidate will hold a doctoral degree in numerical analysis or a
closely related mathematical area. Preference will be given to candidates
with a high international profile whose research interests overlap those of
existing members of the Group, particularly in the solution of large-scale
linear or nonlinear equations, and of eigenvalue and numerical optimization
problems. Although the successful applicant will be expected to interact with
other members of the Group, strong evidence of the ability to work
independently will be expected. Considerable experience of programming in
Fortran and of using standard numerical analysis libraries such as BLAS and
LAPACK is essential. Additional programming skills will be considered an
advantage. Further information on the Group can be found on
http://www.cse.clrc.ac.uk/Group/CSENAG
The post will be available from the beginning of May 2000 and applicants
should indicate when they would be able to take up the position should their
application be successful.
The salary range is between 18,620 and 26,600 pounds (Band 5) or 23,240 and
33,200 pounds (Band 4), depending on qualifications and experience. A
non-contributory pension scheme and a generous leave allowance are offered.
Application forms can be obtained from: Operations Group, HR Division,
Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX.
Telephone (01235) 445435 (answerphone) quoting reference VN1920, or e-mail
recruit@rl.ac.uk. More information about CCLRC and application forms are
available from CCLRCs World Wide Web pages at http://www.cclrc.ac.uk
All applications must be returned by 27 April 2000.
The CCLRC is committed to Equal Opportunities and to achieving the Investors
In People standard. A no smoking policy is in operation.
-------------------------------------------------------
Date: Mon, 10 Apr 2000 11:07:29 +0100
From: Lili Koloszar
Subject: Two Open Positions at the University of Zurich
The Department of Mathematics at the University of Zurich has the following
two open positions.
Post-doc in Numerical Analysis and Scientific Computing
The position is integrated in the Numerical Analysis Research Group, and the
duties include independent research in the field of numerical analysis for
solving PDEs with a view towards further scientific qualification.
Participation in the current research projects of the Numerical Analysis Group
and in their teaching activities is required.
Pre-requisites: Ph.D. in mathematics and research experience in the field of
applied and numerical analysis.
Scientific Assistant in Numerical Analysis and Scientific Computing
The duties involve working on a research project for the numerical solution of
partial differential equations on complicated domains by multigrid methods.
The project is sponsored by the Swiss Nationalfonds and should lead to a Ph.D.
thesis. Participation in teaching activities (in German) is also required.
Pre-requisites: University degree in mathematics, computer science or one of
the natural sciences.
Please send your application to
Universitaet Zurich
Institut fur Mathematik
Herrn Prof. Dr. S. Sauter
Winterthurerstr. 190
CH-8057 Zurich
Switzerland
Tel.: ++41 (0) 1 635 5831; eMail: stas@amath.unizh.ch
-------------------------------------------------------
Date: Sun, 02 Apr 2000 21:43:31 -0400
From: Roland Freund
Subject: Copper Mountain 2000 Paper (Freund)
Krylov-Subspace Iterations for Reduced-Order Modeling
in VLSI Circuit Simulation
Roland W. Freund
Bell Laboratories
Room 2C-525
700 Mountain Avenue
Murray Hill, NJ 07974-0636
Abstract
Traditional VLSI circuit simulation is based on the numerical solution of
large-scale stiff nonlinear systems of differential-algebraic equations
(DAEs). Numerical techniques for such DAEs require the repeated solution of
large sparse systems of linear equations, and iterative methods, such as
Krylov-subspace algorithms, seem to be predestined to the solution of these
linear systems. However, for various reasons, standard SPICE-like circuit
simulators employ direct methods, rather than iterative methods.
Nevertheless, the continuing evolution of VLSI circuits has now come to a
point where Krylov-subspace methods are finally becoming mainstream tools in
circuit simulation. More precisely, today, Krylov-subspace iterations are
employed to generate reduced-order models of large linear subsystems of DAEs
that describe large linear subcircuits of the VLSI circuit to be simulated.
In this talk, we explain why and how Krylov-subspace methods are used for
reduced-order modeling in VLSI circuit simulation. We discuss various
desirable and in part conflicting properties of the reduced-order models, such
as high approximation accuracy, stability, and passivity, and show how to
achieve these properties by means of Krylov-subspace iterations. Numerical
results for a variety of circuit examples are presented.
Editor's Note: See http://www.mgnet.org/mgnet-cm2000.html for the full
------------- paper.
-------------------------------------------------------
Date: Mon, 17 Apr 2000 15:18:43 +0200 (MEST)
From: Yvan Notay
Subject: Copper Mountain 2000 paper (Notay)
Flexible Conjugate Gradients
Yvan Notay
Abstract
We analyze the conjugate gradient method with preconditioning slightly
variable from one iteration to the next. To maintain the optimal convergence
properties, we consider a variant proposed by Axelsson that performs an
explicit orthogonalization of the search directions vectors. For this method,
which we refer to as flexible conjugate gradient, we develop a theoretical
analysis that shows that the convergence rate is essentially independent of
the variations in the preconditioner as long as the latter are kept
sufficiently small. We further discuss the real convergence rate on the basis
of some heuristic arguments supported by numerical experiments. Depending on
the eigenvalue distribution corresponding to the fixed reference
preconditioner, several situations have to be distinguished. In some cases,
the convergence is as fast with truncated versions of the algorithm or even
with the standard conjugate gradient method, whereas quite large variations
are allowed without too much penalty. In other cases, the flexible variant
effectively outperforms the standard method, while the need for truncation
limits the size of the variations that can be reasonably allowed.
Editor's Note: See http://www.mgnet.org/mgnet-cm2000.html for the full
------------- paper.
-------------------------------------------------------
Date: Mon, 10 Apr 2000 12:26:12 +0500
From: Craig Douglas
Subject: Copper Mountain Conference on Iterative Methods: Talks
This is the list of talks that were scheduled to take place at the Copper
Mountain Conference on Iterative Methods, which was held from April 2-7.
The list was scanned from the paper program, so please do not laugh too
hard if there are some oddities that I did not catch. Also, if you gave
a talk that is not listed, please send me the title.
M. Adams
Evaluation of a Geometric and an Algebraic Multigrid Method on 3D Finite
Element Problems in Solid Mechanics
P. Arbenz
On Computing Some of the Principal Eigenfrequencies of Cavity Resonators
C. Aro
Iterative Solver Performance on Algebraically Reduced Implicit Mechanical
Linear Systems
D. Aruliah
Preconditioning Strategies for Low Frequency Electromagnetics Simulations
T. Austin
A Divergence-Free Relaxation Scheme in an H^1-Finite Element Space
A. Baker
Reducing Memory Access Costs: Variants of GMRES with Efficient Data Re-use
P. Barton
Sensitivity Analysis of Hybrid Systems: Theory and Numerical Implications
V. Baryamureeba
Solution of Robust Linear Regression Problems by Preconditioned Conjugate
Gradient Type Methods
M. Benzi
On Some New Developments in Approximate Inverse Preconditioning
M. Berndt
On a Multilevel Solver That Utilizes Singular Basis Functions for the Solution
of the Diffusion Equation With Discontinous Coefficient
H. Branden
A Note on Prasitic Solutions
J. Brandts
Calculation of Invariant Subspaces of Large and Sparse Matrices.
M. Brezina
Algebraic Multigrid for Problems with Discontinuous Coefficients
Z. Cai
Multigrid Method for the Poisson Eauation with Corner Singularities
E. Chow
Performance Charateristics of Least Squares Sparse Approximate Inverse
Preconditioners
A. Codd
First-order System Least Squares (FOSLS) for Elliptic Grid Generation (EGG)
T. Chartier
Element Based Algebraic Multigrid (AMGe)
J. Cullum
Algebraic Multigrid: Accelerating the Convergence
C. Dawson
Time-splitting Methods for Chemically Reactive Transport
H. DeGersem
A Multigrid Algorithm for Quasistatic Electromagnetic Simulation
E. de Sturler
Improving the Convergence of the Jacobi-Davidson Algorithm
B. Diskin
Efficient Highly Parallel Multigrid Methods for the Convection Equation
M. Dorobantu
CFD Code Convergence Diagnostics and Acceleration Using the Recursive
Projection Methods
C. Douglas
Almost Fully Utilized Caches for Iterative Methods
Z. Drmac
Perturbation Theory and Iterative Summetric Eigensolvers
V. Druskin
Gaussian Spectral Rules for Second Order Finite-Difference Schemes
V. Eijkhout
The Weighted Distributed Modification ILU Factorisation
H. Elman
Performance and Analysis of Saddle Point Preconditioners for the Discrete
Steady-State Navier-Stokes Equations
M. Embree
Invariant Subspace Convergence for Amoldi's Method Equation
O. Ernst
Acceleration Strategies for Restarted Minimal Residual Methods
R. Falgout
Sparse Multiple Semicoarsened Grids
R. Freund
Krylov-Subspace Iterations for Reduced-Order Modeling in VLSI Circuit
Simulation
J. Fuhrmann
Finite Volume Methods for Systems of Viscous Conservation Laws: Numerical
Analysis and Software
E. Gallopoulos
On the Computational Effectiveness of Transfer Function Approximations to the
Matrix Pseudospectrum
S. Goossens
Mortar Projection in Overlapping Composite Mesh Difference Methods
C.-H. Guo
Iterative Solution of a Matrix Equation Arising in Stochastic Control
A. Grama
Error Controlled Multipole Methods for Arbitrary Particle Distributions
E. Haber
On the Solution of the Linear Systems Which Evolve From Large Scale Inverse
Problems
M. Heinkenschloss
Inexact Sequential Quadratic Programming Methods for the Solution of Inverse
Problems Governed by PDEs
L. Hemmingsson-Franden
Semi Circulant Approximations in Preconditioners for Incompressible Flow
Problems
V.E. Henson
Element-free AMGe: General Algorithms for Computing Interpolation Weights
M. Heroux
Solving Complex-valued Linear Systems via Equivalent Real Formulations
A. C.-W. Ho
Iterative Method for Robin Problems
M. Hochstenbach
JDSUD: A Jacobi-Davidson Like SVD Method
S. Holgren
Convergence Acceleration for the Euler Equations
G. Horton
An AMG-Like Solution Method for Markov Chains
M. Huhtanen
Hermitian Lanczos Method for Normal Matrices
L. Jenkins
Aggregation-Based Domain Decomposition Methods for Unsaturated Flow II:
Theory and Convergence
J. Jones
Preconditioners for Newton-Klylov Solvers of Richards' Equation
C. Keller
Constraint Preconditioning for Indefinite Linear Systems
T. Kelley
Aggregation-Based Domain Decomposition Methods for Unsaturated Flow 1:
Motivation and Design
C. Kees
Multilevel Schwarz Preconditioners for Two- and Three-phase Flow in Porous
S. Kim
Finite Element Preconditioning Cubic Spline Collocation Method of Elliptic
Equations
L. Knizhnennai
Lanezos Method and Pad~-Chebyshev Approximation of Markov Functions
D. Knoll
On Newton-Krylov Methods in Solidifying Flow Applications
A. Knyazev
Toward the Optimal Preconditioned Eigensolver
J. Korsawe
Nonlinear First Order Systems Least Squares Finite Element Multilevel
Computations: Extended Relaxation in H (div)
D. Lahaye
Solving Magnetics Field - Electric Circuit Coupled Systems
R. Larsen
Iterative Algorithms for Least Squares Problems with Multiple Right-hand Sides
E. Larsson
Parallelization of a Domain Decomposition Method for the Helmholtz Equation
R. Lehoucq
A Penalized Finite Element Method for Pure Neumann Problem
L. Little
Domain Decomposition of Solid-Liquid Flows
D. Loghin
A Fundamental Solution Preconditioner for the Navier-Stokes Equations
L. Machiels
Output Bounds for Partial Differential Equations: Application to Reduced
Order Approximations
H. MacMillan
First-Order Systems Least Squares for Electrical Impedance Tomography
S. McCormick
Least-Squares Methods for Partial Differential Equations
G. Meurant
On the Perturbation of the Incomplete Cholesky Factorization
J. More
TAO: Toolkit for Advanced Optimization
R. Morgan
An Algorithm for Outlining the Spectrum of a Large Matrix and Determining
Multiplicity of Eigenvalues
B. Morini
A Trust Region Method for Bound-Constrained Nonlinear Systems
V. Mousseau
Newton-Krylov Methods for Time Accurate Solution of Multi-Physics Hyperbolic
Systems
O. Nevanlinna
Krylov Subspace and Low Rank Perturbations
K. Neymeyr
A Geometric Convergence Theory for Preconditioned Inverse Iteration
Y. Notay
Conjugate Gradient with Variable Preconditioning
V. Pan
Newton's Structured Matrix Iteration
S. Parter
Preconditioning Legendre Spectral Collocation Methods for Elliptic Problems:
Finite Difference Operators and Finite Element Operators
J. Pasciak
Nonconforming Approximation Methods Based on Nonmatching Grids
M. Pernice
A Newton-Krylov-Multigrid Method for the Incompressible Navier-Stokes
Equations
L. Petzold
Sensitivity Analysis and Software for Large-Scale Differential-Algebraic
Systems
A. Pothen
A Parallel Algorithm for Incomplete Factorization Preconditioning
M. Putti
Iterative Methods for the Partial Symmetric Eigenproblems
D. Quinlan
Elliptic Solvers with Adaptive Mesh Refinement on Complex Geometries
A. Ramage
Iterative Convergence for Stabilised Finite Element Discretisations of
Advection-Diffusion Problems
R. Renaut
Iterative Determination of Kinetic Constants from PET Data Utilizing Total
Least Squares Estimates
U. Ruede
Adaptive Multigrid in Space and Time
J. Ruge
FOSPACK: A FOSLS/AMG Package
Y. Saad
Parallel Solution of Eigenvalue Problems in Electronic Structure Calculations
E. W. Sachs
An Indefinite Preconditioner for Quadratic Control Problems
S.A. Salvini
Sparse Iterative Solvers for Shared Memory Parallelism
V. Sana
Preconditioning Techniques for the Genrealized Navier Problem
M. Shaskov
Mimetic Discretizations of Diffusion Equation and Constructions of
Preconditioners
M. Sosonkina
Rational Approximation Preconditioners for General Sparse Linear Systems
G. Starke
A Levenberg-Marquardt Method for Nonlinear Least-Squares Finite Element
Computations
A. Stathopoulos
A Case for a Biorthogonal Jacobi-Davidson Method: Restarting and Correction
S. Sundberg
Parallel Semi-Toeplitz Preconditioners for Combustor Flows
P. Sunqvist
Preconditioners based on fundamental solutions
D. Swesty
Parallelizable Preconditioners for Multigroup Flux-limited Diffusion Problems
D. Szyld
Algebraic Theory of Additive and Multiplicative Schwarz
T. Tefy
Preconditioned Newton GMRES Methods for Non-Linear Systems of PDE's of
Unsteady Compressible Fluid Flow
M. Tocci
Sensitivity Analysis using Inexact Newton Methods
V. Tolstykh
New First-Order Algorithms for High-Dimensional Quadratic Optimization
A. Toselli
Neumann-Neumann and Feti Preconditioners for Edge Element Approximation of
Maxwell's Equation
N. Trefethen
Generalizing Eigenvalue Theorems to Pseudospectia Theorems
M. Trummer
Preconditioning Spectral Methods for First Order Equations
H.M. Tufo
A Parallel Direct Solver Package for Coarse Grid Problems
H. van der Vorst
Ritz and Harmonic Ritz Approximates
P. Vassilevski
Graph based multilevel algorithms for Preconditioning Finite Element Problems
M. Verbeek
Smoother Dependent Interpolation for AMG
J. Vogel
FQMR: A Flexible Quasi-Minimal Residual Method with Inexact Preconditioning
K. Vuik
Deflated ICCG Applied to Problems with Extreme Contrasts in the Coefficients
A. Wathen
Preconditioning Constrained Systems
M. Wheeler
A Problem Solving Environment for Coupling Multiphysics and Multiple Domains
in Porous Media
R. Wienands
On Three-grid Fourier Analysis of Multigrid
J. Wilson
Efficient Solver for Mixed and Control- Volume Mixed Finite Element Methods in
Three Dimensions
C. Woodward
Implicit Solution of Radiation-Diffusion Problems Using Newton-Krylov
Multigrid Methods
T. Wright
Computation of Pseudospectra Using ARPACK and EIGS
C. Yang
Large-Scale Normal Coordinate Analysis for Molecular Structures
D. Yang
Accurate Numeric Methods for Interface Problems with Strongly Discontinous
Coefficients
U. Yang
BoomerAMG: a Parallel Algebraic Multigrid Solver: Implementation and
Enhancements
J. Zhang
Adaptive ILU Preconditioning Strategies in Semiconductor Process Modeling
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End of MGNet Digest
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