Definition Of Capacited P-medians By A Modified Max Min Ant System With Local Search

This work introduces a modified MAX MIN Ant System (MMAS) designed to solve the Capacitated p-Medians Problem (CPMP). It presents the most relevant steps towards the implementation of an MMAS to solve the CPMP, including some improvements on the original MMAS algorithm, such as the use of a density model in the information heuristics and a local search adapted from the uncapacitated p-medians problem. Extensions to a recently proposed updating rule for the pheromone level, aiming at improving the MMAS ability to deal with large-scale instances, are also presented and discussed: Some simulations are performed using instances available from the literature, and well-known heuristics are employed for benchmarking. © Springer-Verlag Berlin Heidelberg 2004.331610941100Osman, I.H., Christofides, N., Capacitated Clustering Problems by Hybrid Simulated Annealing and Tabu Search (1994) Int. Trans. Opl. Res., 1 (3), pp. 317-336. , Pergamons Press, England, 1994Garey, M.R., Johnson, D.S., (1979) Computers and Intractability: A Guide to the Theory of NP-Completeness, , San Francisco: FreemanDorigo, M., (1992) Optimization, Learning and Natural Algorithms, , Ph.D.Thesis, Politecnico di Milano, Italy, in ItalianStützle, T., Hoos, H.H., The MAX-MIN ant system and local search for the traveling salesman problem (1997) Proceedings of the IEEE International Conference on Evolutionary Computation (ICEC'97), pp. 309-314. , T. Back, Z. Michalewicz, and X. Yao, editors, IEEE Press, Piscataway, NJ, USAStützte, T., Dorigo, M., ACO algorithms for the Quadratic Assignment Problem (1999) New Ideas in Optimization, pp. 33-50. , D. Corne, M. Dorigo, and F. Glover, editors, McGraw-HillAhmadi, S., Osman, I.H., Density based problem space search for the capacitated clustering problem (2004) Annals for Operational Research, , in pressResende, G.C.M., Werneck, F.R., On the implementation of a swap-based local search procedure for the p-median problem (2003) Proceedings of the Fifth Workshop on Algorithm Engineering and Experiments (ALENEX'O3), pp. 119-127. , Richard E. Ladner (Ed.), SIAM, PhiladelphiaTeitz, M.B., Bart, P., Heuristic Methods for Estimating the Generalized Vertex Median of a Weighted Graph (1968) Operation Research, 16 (5), pp. 955-961De França, P.O., Von Zuben, F.J., De Castro, L.N., A Max Min Ant System Applied to the Capacitated Clustering Problem (2004) IEEE International Workshop on Machine Learning for Signal Processing, , São Luis, BrazilBlum, C., Roli, A., Dorigo, M., Hc-Aco: The hyper-cube framework for Ant Colony Optimization (2001) Proceedings of MIC'2001 - Meta-heuristics International Conference, 2, pp. 399-403. , Porto, PortugalBlum, C., Dorigo, M., The Hyper-Cube Framework for Ant Colony Optimization (2004) IEEE Transactions on Systems, Man and Cybernetics, Part B, 34 (2), pp. 1161-1172Lorena, L.A.N., Senne, E.L.F., Local Search Heuristics for Capacitated P-Median Problems (2003) Networks and Spatial Economics, 3, pp. 407-41

Bio-inspired algorithms applied to dynamic optimization

Orientadores: Fernando Jose Von Zuben, Leandro Nunes de CastroDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: Esta dissertação propõe algoritmos bio-inspirados para a solução de problemas de otimização dinâmica, ou seja, problemas em que a superfície de otimização no espaço de busca sofre variações diversas ao longo do tempo. Com a variação, no tempo, de número, posição e qualidade dos ótimos locais, as técnicas de programação matemática tendem a apresentar uma acentuada degradação de desempenho, pois geralmente foram concebidas para tratar do caso estático. Algoritmos populacionais, controle dinâmico do número de indivíduos na população, estratégias de busca local e uso eficaz de memória são requisitos desejados para o sucesso da otimização dinâmica, sendo contemplados nas propostas de solução implementadas nesta dissertação. Os algoritmos a serem apresentados e comparados com alternativas competitivas presentes na literatura são baseados em funcionalidades e estruturas de processamento de sistemas imunológicos e de colônias de formigas. Pelo fato de considerarem todos os requisitos para uma busca eficaz em ambientes dinâmicos, o desempenho dos algoritmos imuno-inspirados se mostrou superior em todos os critérios considerados para comparação dos resultados dos experimentos.Abstract: This dissertation proposes bio-inspired algorithms to solve dynamic optimization problems, i.e., problems for which the optimization surface on the search space suffers several changes over time. With such variation of number, position and quality of local optima, mathematical programming techniques may present degradation of performance, because they were usually conceived to deal with static problems. Population-based algorithms, dynamic control of the population size, local search strategies and an efficient memory usage are desirable requirements to a proper treatment of dynamic optimization problems, thus being incorporated into the solution strategies implemented here. The algorithms to be presented, and compared with competitive alternatives available in the literature, are based on functionalities and processing structures of immune systems and ant colonies. Due to the capability of incorporating all the requirements for an efficient search on dynamic environments, the immune-inspired approaches overcome the others in all the performance criteria adopted to evaluate the experimental results.MestradoEngenharia de ComputaçãoMestre em Engenharia Elétric