An efficient algorithm for nonlinear integer programming

M.Sc., Faculty of Sciences, University of the Witwatersrand, 2011Abstract This dissertation is concerned with discrete global optimization of nonlinear problems. These problems are constrained and unconstrained and are not easily solvable since there exists multiplicity of local and global minima. In this dissertation, we study the current methods for solving such problems and highlight their ine ciencies. We introduce a new local search procedure. We study the rapidly-exploring random tree (RRT) method, found mostly in the research area of robotics. We then design two global optimization algorithms based on RRT. RRT has never been used in the eld of global optimization. We exploit its attractive properties to develop two new algorithms for solving the discrete nonlinear optimization problems. The rst method is called RRT-Optimizer and is denoted as RRTOpt. RRTOpt is then modi ed to include probabilistic elements within the RRT. We have denoted this method by RRTOptv1. Results are generated for both methods and numerical comparisons are made with a number of recent methods

Meta-heuristics in cellular manufacturing: A state-of-the-art review

Meta-heuristic approaches are general algorithmic framework, often nature-inspired and designed to solve NP-complete optimization problems in cellular manufacturing systems and has been a growing research area for the past two decades. This paper discusses various meta-heuristic techniques such as evolutionary approach, Ant colony optimization, simulated annealing, Tabu search and other recent approaches, and their applications to the vicinity of group technology/cell formation (GT/CF) problem in cellular manufacturing. The nobility of this paper is to incorporate various prevailing issues, open problems of meta-heuristic approaches, its usage, comparison, hybridization and its scope of future research in the aforesaid area

Um Algoritmo Híbrido entre Evolução Diferencial e Neder - Mead Usando Entropia para Problemas de Otimização Não - Linear Inteiro Misto.

Vários problemas em engenharia são formulados como problemas de otimização não-lineares inteiros mistos. Métodos estocásticos vem sendo utilizados devido ao seu desempenho, flexibilidade, adaptabilidade e robustez. Evolução Diferencial pode ser utilizado em funções de qualquer natureza e possui habilidades em busca global, porém, tais habilidades não são refletidas na busca local. Este trabalho propõe uma abordagem híbrida entre os algoritmos Evolução Diferencial e Nelder-Mead para problemas de otimização não-linear inteira misto, onde o chaveamento é realizado através da entropia da população. O algoritmo Nelder-Mead foi estendido para manipular variáveis inteiras. O primeiro protótipo foi desenvolvido para solucionar problemas de otimização não-linear inteira sem restrições. O método Alfa Constrained foi incorporado para tratar problemas de otimização não-linear inteira com restrições e o algoritmo demonstrou sua eficácia. Por último, a abordagem foi testada utilizando problemas de otimização não-linear inteira mista com restrições e superou alguns resultados reportados na literatura. A principal vantagem deste método é a habilidade de realizar o chaveamento de acordo com a entropia da população durante a busca

Meta-heuristics development framework: Design and applications

Master'sMASTER OF SCIENC

Learning algorithms for adaptive digital filtering

In this thesis, we consider the problem of parameter optimisation in adaptive digital filtering. Adaptive digital filtering can be accomplished using both Finite Impulse Response (FIR) filters and Infinite Impulse Response Filters (IIR) filters. Adaptive FIR filtering algorithms are well established. However, the potential computational advantages of IIR filters has led to an increase in research on adaptive IIR filtering algorithms. These algorithms are studied in detail in this thesis and the limitations of current adaptive IIR filtering algorithms are identified. New approaches to adaptive IIR filtering using intelligent learning algorithms are proposed. These include Stochastic Learning Automata, Evolutionary Algorithms and Annealing Algorithms. Each of these techniques are used for the filtering problem and simulation results are presented showing the performance of the algorithms for adaptive IIR filtering. The relative merits and demerits of the different schemes are discussed. Two practical applications of adaptive IIR filtering are simulated and results of using the new adaptive strategies are presented. Other than the new approaches used, two new hybrid schemes are proposed based on concepts from genetic algorithms and annealing. It is shown with the help of simulation studies, that these hybrid schemes provide a superior performance to the exclusive use of any one scheme