Now showing items 1-10 of 43
An Implementation of a Parallel Primal-Dual Interior Point Method for Multicommodity Flow Problems
An implementation of the primal-dual predictor-corrector interior point method is specialized to solve linear multicommodity flow problems. The block structure of the constraint matrix is exploited via parallel computation. ...
A Diagonal-Secant Update Technique for Sparse Unconstrained Optimization
This paper presents a diagonal-secant modification of the successive element correction method, a finite-difference based method, for sparse unconstrained optimization. This new method uses the gradient values more efficiently ...
Variations of Structured Broyden Families for Nonlinear Least Squares Problems
In this paper, we consider structured quasi-Newton methods for finding a local solution to nonlinear least squares problems. This paper is concerned with the line search globalization method. Recently, factorized versions ...
A Differential Semblance Criterion for Inversion of Multioffset Seismic Reflection Data
Mean-square error leading to least-squares inversion of multioffset reflection seismograms is insensitive to velocity trend information except in the immediate vicinity of a kinematically correct model. In contrast, differential ...
Mixed Methods on Quadrilaterals and Hexahedra
We describe a new family of discrete spaces suitable for use with mixed methods on general quadrilateral and hexahedral elements. The new spaces are natural in the sense of differential geometry, so all the usual mixed ...
Three-Dimensional Bioremediation Modeling in Heterogeneous Porous Media
Recently Rice University and Pacific Northwest Laboratory (PNL) have begun a collaborative research effort that involves laboratory, field, and simulation work directed toward validating remediation strategies, including ...
Time-Splitting Methods for Advection-Diffusion-Reaction Equations Arising in Contaminant Transport
Two time-splitting methods for advection-diffusion-reaction problems are discussed and analyzed. Numerical results for the first approach applied to bioremediation of contaminants in groundwater are presented.
Velocity Inversion by Differential Semblance Optimization for 2D Common Source Data
Differential Semblance Optimization ("DSO") is a variant of data-fitting (least-squares) inversion of reflection seismograms. The misfit functions used in other implementations of least-squares inversion (for example ...
A Modified Predictor-Corrector Algorithm for Locating Weighted Centers in Linear Programming
In certain applications of linear programming, some particular solutions called the weighted centers of the solution set are often desired, giving rise to the need of algorithms capable of locating such centers. In this ...