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Now showing items 1-10 of 16

#### Choosing Regularization Parameters in Iterative Methods for Ill-Posed Problems

(1998-10-15)

Numerical solution of ill-posed problems is often accomplished by
discretization (projection onto a finite dimensional subspace) followed by
regularization. If the discrete problem has high dimension, though,
typically ...

#### TIKHONOV REGULARIZATION AND TOTAL LEAST SQUARES

(1998-10-15)

Discretizations of inverse problems lead to systems of linear equations
with a highly ill-conditioned coefficient matrix, and in order to
compute stable solutions to these systems it is necessary to apply
regularization ...

#### A Parallel Inexact Newton Method Using a Krylov Multisplitting Algorithm

(1998-10-15)

Abstract. We present a paraUel variant of the inexact Newton algorithm
that uses the Krylov multisplitting algorithm (KMS) to compute the
approxrmate Newton direction. The algorithm can be used for solving
unconstrained ...

#### Restoring Images Degraded by Spatially-Variant Blur

(1998-10-15)

Restoration of images that have been blurred by the effects
of a Gaussian blurring function is an ill-posed but well-studied
problem. Any blur that is spatially invariant can be expressed
as a convolution kernel in an ...

#### Regularization Algorithms Based on Total Least Squares

(1998-10-15)

Discretizations of inverse problems lead to systems of linear equations
with a highly ill-conditioned coefficient matrix, and in order to
compute stable solutions to these systems it is necessary to apply
regularization ...

#### Efficient Iterative Solution of the Three-Dimensional Helmholtz Equation

(1998-10-15)

We examine preconditioners for the discrete indefinite Helmholtz equation on a
three-dimensional box-shaped domain with Sommerfeld-like boundary conditions.
The preconditioners are of two types. The first is derived
by ...

#### Eigenanalysis of Some Preconditioned Helmholtz Problems

(1998-10-15)

In this work we calculate the eigenvalues obtained by
preconditioning the discrete Helmholtz operator with
Sommerfeld-like boundary conditions on a rectilinear domain, by
a related operator with boundary conditions
that ...

#### A Semi-Discrete Matrix Decomposition for Latent Semantic Indexing in Information Retrieval

(1998-10-15)

The vast amount of textual information available today is useless unless
it can be effectively and efficiently searched. In information
retrieval, we wish to match queries with relevant documents. Documents
can be ...

#### Large Latent Semantic Indexing via a Semi-Discrete Matrix Decomposition

(1998-10-15)

With the electronic storage of documents comes the possibility of
building search engines that can automatically choose documents relevant
to a given set of topics. In information retrieval, we wish to match
queries ...

#### Adaptive Use of Iterative Methods in Interior Point Methods for Linear Programming

(1998-10-15)

In this work we devise efficient algorithms for finding the search
directions for interior point methods applied to linear programming
problems. There are two innovations. The first is the use of updating of
preconditioners ...