Now showing items 21-30 of 126
Local Analysis of Inexact Quasi-Newton Methods
Quasi-Newton methods are well known iterative methods for solving nonlinear problems. At each stage, a system of linear equations has to be solved. However, for large scale problems, solving the linear system of equations ...
ønix: A Unix Emulator for VAX/VMS
Nonparametric Mode Estimation for Higher Dimensional Densities
In this study a family of estimators is developed for local maxima, or modes, of a multivariate probability density function. The mode estimators are computationally feasible iterative optimization procedures utilizing ...
Program Specification Testing within an Integrated Programming Environment
Our research breaks down into three parts. First, we are exploring the mathematical foundations of program specifications and applying the understanding that we gain to the subject of specification language design. The success of a specification and testing system hinges on the quality of the underlying specification language. We are particularly concerned with the special problems posed by floating point arithmetic and concurrency. Second, we are developing more sophisticated methods - employing a judicious combination of verification and testing - for certifying that programs implement their formal specifications. Finally, to test the effectiveness of ideas, we are building an experimental program specification and testing system as an extension of the R^n Programming Environment already under development at Rice....
Least-Change Secant Update Methods with Inaccurate Secant Conditions
In this paper, we investigate the role of the secant or quasi-Newton condition in the sparse Broyden or Schubert update method for solving systems of nonlinear equations whose Jacobians are either sparse, or can be approximated acceptably by conveniently sparse matrices. We develop a general theory on perturbations to the secant equation that will still allow a proof of local q-linear convergence. To illustrate the theory, we show how to generalize the standard secant condition to the case when the function difference is contaminated by noise....
On Secant Updates for Use in General Constrained Optimization
In this paper we present two new classes of SQP secant methods for the equality constrained optimization problem. One class of methods uses the SQP augmented Lagrangian formulation, while the other class uses the SQP ...
An Interactive Approach for Solving Multi-Objective Optimization Problems
Multi-objective optimization problems are characterized by the need to consider multiple, and possibly conflicting, objectives in the solution process. We present an approach based on the use of interactive computer graphics ...
High-Frequency Perturbational Analysis of the Surface Point-Source Response of a Layered Fluid
We linearize the relation between the density and velocity profiles of a layered fluid subject to a specified surface point traction, and study a precritical projection of its surface motion. We decompose the resulting ...