A modified secant method for unconstrained minimization

A gradient-secant algorithm for unconstrained optimization problems is presented. The algorithm uses Armijo gradient method iterations until it reaches a region where the Newton method is more efficient, and then switches over to a secant form of operation. It is concluded that an efficient method for unconstrained minimization has been developed, and that any convergent minimization method can be substituted for the Armijo gradient method

Nonmonotone hybrid tabu search for Inequalities and equalities: an experimental study

The main goal of this paper is to analyze the behavior of nonmonotone hybrid tabu search approaches when solving systems of nonlinear inequalities and equalities through the global optimization of an appropriate merit function. The algorithm combines global and local searches and uses a nonmonotone reduction of the merit function to choose the local search. Relaxing the condition aims to call the local search more often and reduces the overall computational effort. Two variants of a perturbed pattern search method are implemented as local search. An experimental study involving a variety of problems available in the literature is presented.Fundação para a Ciência e a Tecnologia (FCT

Sample-path solutions for simulation optimization problems and stochastic variational inequalities

inequality;simulation;optimization

Review of: Newton Methods for Nonlinear Problems: Affine Invariance and Adaptive Algorithms, by P. Deuflhard

In the context of solving nonlinear equations, the term affine invariance was introduced to describe the fact that when a function F: Rn → Rn is transformed to G = AF ,where A is an invertible matrix, then the equation F(x) = 0 has the same solutions as G(x) = 0, and the Newton iterates Xk+1 = Xk-F\u27(Xk)-1F(Xk) remain unchanged when F is replaced by G. The idea was that this property of Newton\u27s method should be reflected in its convergence analysis and practical implementation, not only on aesthetic grounds but also because the resulting algorithms would likely be less sensitive to scaling, conditioning, and other numerical issues

Two New Predictor-Corrector Iterative Methods with Third- and Ninth-Order Convergence for Solving Nonlinear Equations

In this paper, we suggest and analyze two new predictor-corrector iterative methods with third and ninth-order convergence for solving nonlinear equations. The first method is a development of [M. A. Noor, K. I. Noor and K. Aftab, Some New Iterative Methods for Solving Nonlinear Equations, World Applied Science Journal, 20(6),(2012):870-874.] based on the trapezoidal integration rule and the centroid mean. The second method is an improvement of the first new proposed method by using the technique of updating the solution. The order of convergence and corresponding error equations of new proposed methods are proved. Several numerical examples are given to illustrate the efficiency and performance of these new methods and compared them with the Newton's method and other relevant iterative methods. Keywords: Nonlinear equations, Predictor–corrector methods, Trapezoidal integral rule, Centroid mean, Technique of updating the solution; Order of convergence

Augmented Lagrangian and differentiable exact penalty methods

Bibliography: leaves 13-14."July 1981""National Science Foundation Grant no. NSF/ECS 79-20834."Dimitri P. Bertsekas

On Convergence Properties of the EM Algorithm for Gaussian Mixtures

"Expectation-Maximization'' (EM) algorithm and gradient-based approaches for maximum likelihood learning of finite Gaussian mixtures. We show that the EM step in parameter space is obtained from the gradient via a projection matrix $P$, and we provide an explicit expression for the matrix. We then analyze the convergence of EM in terms of special properties of $P$ and provide new results analyzing the effect that $P$ has on the likelihood surface. Based on these mathematical results, we present a comparative discussion of the advantages and disadvantages of EM and other algorithms for the learning of Gaussian mixture models

Calculation of chemical and phase equilibria

Bibliography: pages 167-169.The computation of chemical and phase equilibria is an essential aspect of chemical engineering design and development. Important applications range from flash calculations to distillation and pyrometallurgy. Despite the firm theoretical foundations on which the theory of chemical equilibrium is based there are two major difficulties that prevent the equilibrium state from being accurately determined. The first of these hindrances is the inaccuracy or total absence of pertinent thermodynamic data. The second is the complexity of the required calculation. It is the latter consideration which is the sole concern of this dissertation

Global optimization: techniques and applications

Optimization problems arise in a wide variety of scientific disciplines. In many practical problems, a global optimum is desired, yet the objective function has multiple local optima. A number of techniques aimed at solving the global optimization problem have emerged in the last 30 years of research. This thesis first reviews techniques for local optimization and then discusses many of the stochastic and deterministic methods for global optimization that are in use today. Finally, this thesis shows how to apply global optimization techniques to two practical problems: the image segmentation problem (from imaging science) and the 3-D registration problem (from computer vision)