Browsing Computational and Applied Mathematics by Title
Now showing items 446465 of 583

Quantitative Object Reconstruction using Abel Transform XRay Tomography and Mixed Variable Optimization
(200702)This paper introduces a new approach to the problem of quantitatively reconstructing cylindrically symmetric objects from radiograph data obtained via xray tomography. Specifically, a mixed variable programming (MVP) ... 
QuasiNewton Methods and Galerkin Procedures for Nonlinear Elliptic Boundary Value Problems
(198312)Least change secant update strategies are derived that are compatible with algebraic systems of nonlinear equations arising when Galerkin procedures are applied to nonlinear elliptic boundary value problems. The resulting ... 
RankTwo Relaxation Heuristics for MaxCut and Other Binary Quadratic Programs
(200011)Semidefinite relaxation for certain discrete optimization problems involves replacing a vectorvalued variable by a matrixvalued one, producing a convex program while increasing the number of variables by an order of ... 
Reconstruction of Lamé Moduli and Density at the Boundary Enabling Directional Elastic Wavefield Decomposition
(2017)We consider the inverse boundary value problem for the system of equations describing elastic waves in isotropic media on a bounded domain in $\mathbb{R}^3$ via a finitetime Laplace transform. The data are the dynamical ... 
Recovering an Optimal LP Basis from an Interior Point Solution
(199110)An important issue in the implementation of interior point algorithms for linear programming is the recovery of an optimal basic solution from an optimal interior point solution. In this paper we describe a method for ... 
Reducible Nonlinear Programming Problems
(198505)In this thesis we are concerned with general nonlinear programming problems in which the variables can be naturally separated into two groups. This separation has the property that if the variables in one of the groups are ... 
Reoptimization in InteriorPoint Methods with Application to Integer Programming
(199905)This thesis examines current reoptimization techniques for interiorpoint methods available in the literature and studies their efficacy in a branchandbound framework for 0/1 mixed integer programming problems. This work ... 
ResidualBased Adaptivity and PWDG Methods for the Helmholtz Equation
(2015)We present a study of two residual a posteriori error indicators for the plane wave discontinuous Galerkin (PWDG) method for the Helmholtz equation. In particular, we study the $h$version of PWDG in which the number of ... 
Resolving Degeneracy in Linear Programs: Steepest Edge, Steepest Ascent, and Closest Ascent
(199107)While variants of the steepest edge pivoting rule are commonly used in linear programming codes they are not known to have the theoretically attractive property of avoiding an infinite sequence of pivots at points of ... 
Restricted 2factors in Bipartite Graphs
(200010)The krestricted 2factor problem is that of finding a spanning subgraph consisting of disjoint cycles with no cycle of length less than or equal to k. It is a generalization of the well known Hamilton cycle problem and ... 
Reverse Time Migration with Optimal Checkpointing
(200611)The optimal checkpointing algorithm (Griewank and Walther, 2000) minimizes the computational complexity of the adjoint state method. Applied to reverse time migration, optimal checkpointing eliminates (or at least drastically ... 
Ritz Value for NonHermitian Matrices
(2012)RayleighRitz eigenvalue estimates for Hermitian matrices obey Cauchy interlacing, which has helpful implications for theory, applications, and algorithms. In contrast, few results about the Ritz values of nonHermitian ... 
Robustness Optimization for Constrained, Nonlinear Programming Problems
(199703)In realistic situations, engineering designs should take into consideration random aberrations from the stipulated design variables arising from manufacturing variability. Moreover, many environmental parameters are often ... 
RUF 1.0 User Manual
(199408) 
Safeguarded Use of the Implicit Restarted Lanczos Technique for Solving Nonlinear Structural Eigensystems
(199306)This paper presents a new algorithms for evaluating the eigenvalues and their corresponding eigenvectors for large scale nonlinear eigensystems in structural dynamics. The algorithm is based on solving a sequence of algebraic ... 
Safeguarding Hessian Approximations in Trust Region Algorithms
(198705)In establishing global convergence results for trust region algorithms applied to unconstrained optimization, it is customary to assume either a uniform upper bound on the sequence of Hessian approximations or an upper ... 
Scattering and dip angle decomposition based on subsurface offset extended waveequation migration
(2016)An angledependent reflection coefficient is recovered by seismic migration in the angle domain. We have developed a postmigration technique for computing scattering and dip angle commonimage gathers (CIGs) from seismic ... 
Schwarz Methods with Local Refinement for the pVersion Finite Element Method
(199301)We study local refinement for an additive Schwarz method with overlap using the pversion finite element method, introduced in a previous paper. We consider linear, scalar, selfadjoint, second order elliptic problems and ... 
Second Order Behavior of Pattern Search Algorithms
(200401)Previous analyses of pattern search algorithms for unconstrained and linearly constrained minimization have focused on proving convergence of a subsequence of iterates to a limit point satisfying either directional or ... 
Segmented Data Files: An I/O Standard
(199105)