Improved dynamical particle swarm optimization method for structural dynamics

A methodology to the multiobjective structural design of buildings based on an improved particle swarm optimization algorithm is presented, which has proved to be very efficient and robust in nonlinear problems and when the optimization objectives are in conflict. In particular, the behaviour of the particle swarm optimization (PSO) classical algorithm is improved by dynamically adding autoadaptive mechanisms that enhance the exploration/exploitation trade-off and diversity of the proposed algorithm, avoiding getting trapped in local minima. A novel integrated optimization system was developed, called DI-PSO, to solve this problem which is able to control and even improve the structural behaviour under seismic excitations. In order to demonstrate the effectiveness of the proposed approach, the methodology is tested against some benchmark problems. Then a 3-story-building model is optimized under different objective cases, concluding that the improved multiobjective optimization methodology using DI-PSO is more efficient as compared with those designs obtained using single optimization.Peer ReviewedPostprint (published version

Quantifying the Impact of Parameter Tuning on Nature-Inspired Algorithms

The problem of parameterization is often central to the effective deployment of nature-inspired algorithms. However, finding the optimal set of parameter values for a combination of problem instance and solution method is highly challenging, and few concrete guidelines exist on how and when such tuning may be performed. Previous work tends to either focus on a specific algorithm or use benchmark problems, and both of these restrictions limit the applicability of any findings. Here, we examine a number of different algorithms, and study them in a "problem agnostic" fashion (i.e., one that is not tied to specific instances) by considering their performance on fitness landscapes with varying characteristics. Using this approach, we make a number of observations on which algorithms may (or may not) benefit from tuning, and in which specific circumstances.Comment: 8 pages, 7 figures. Accepted at the European Conference on Artificial Life (ECAL) 2013, Taormina, Ital

Artificial Immune Systems - Models, algorithms and applications

Copyright © 2010 Academic Research Publishing Agency.This article has been made available through the Brunel Open Access Publishing Fund.Artificial Immune Systems (AIS) are computational paradigms that belong to the computational intelligence family and are inspired by the biological immune system. During the past decade, they have attracted a lot of interest from researchers aiming to develop immune-based models and techniques to solve complex computational or engineering problems. This work presents a survey of existing AIS models and algorithms with a focus on the last five years.This article is available through the Brunel Open Access Publishing Fun

Scalarizing Functions in Decomposition-Based Multiobjective Evolutionary Algorithms

Decomposition-based multiobjective evolutionary algorithms (MOEAs) have received increasing research interests due to their high performance for solving multiobjective optimization problems. However, scalarizing functions (SFs), which play a crucial role in balancing diversity and convergence in these kinds of algorithms, have not been fully investigated. This paper is mainly devoted to presenting two new SFs and analyzing their effect in decomposition-based MOEAs. Additionally, we come up with an efficient framework for decomposition-based MOEAs based on the proposed SFs and some new strategies. Extensive experimental studies have demonstrated the effectiveness of the proposed SFs and algorithm

A decomposition-based multiobjective evolutionary algorithm with angle-based adaptive penalty

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.A multiobjective evolutionary algorithm based on decomposition (MOEA/D) decomposes a multiobjective optimization problem (MOP) into a number of scalar optimization subproblems and optimizes them in a collaborative manner. In MOEA/D, decomposition mechanisms are used to push the population to approach the Pareto optimal front (POF), while a set of uniformly distributed weight vectors are applied to maintain the diversity of the population. Penalty-based boundary intersection (PBI) is one of the approaches used frequently in decomposition. In PBI, the penalty factor plays a crucial role in balancing convergence and diversity. However, the traditional PBI approach adopts a fixed penalty value, which will significantly degrade the performance of MOEA/D on some MOPs with complicated POFs. This paper proposes an angle-based adaptive penalty (AAP) scheme for MOEA/D, called MOEA/D-AAP, which can dynamically adjust the penalty value for each weight vector during the evolutionary process. Six newly designed benchmark MOPs and an MOP in the wastewater treatment process are used to test the effectiveness of the proposed MOEA/D-AAP. Comparison experiments demonstrate that the AAP scheme can significantly improve the performance of MOEA/D

New Insights to Approximate the Pareto Optimal Front in Evolutionary Multiobjective Optimization. An Application to Students’ Satisfaction

Los resultados de la segunda parte demuestran el buen comportamiento de la combinación de técnicas econométricas y multiobjetivo, especialmente cuando utilizamos algoritmos evolutivos, para la resolución de problemas socio-económicos con la finalidad de encontrar la compensación (trade-offs) entre los objetivos estudiados y así poder sugerir mejoras, en este caso, en economía de la educación.La tesis presentada se basa en el desarrollo de nuevos algoritmos evolutivos para resolver problemas de optimización multiobjetivo, especialmente problemas con más de tres funciones objetivos, y en la modelización y resolución de un problema de economía de la educación. Dicha tesis está realizada en la modalidad de compendio de artículos y se compone de tres de los mismos. Los dos primeros relacionados con el desarrollo de un nuevo algoritmo evolutivo. En ellos, partiendo del algoritmo Global Weighting Achievement Scalarizing Fucntion Genetic Algorithm (GWASF-GA) (Saborido, Ruiz, and Luque, 2017), se plantea y desarrolla un nuevo algoritmo centrado en la adaptación de los vectores de pesos durante el proceso de ejecución, que ofrece muy buenos resultados en comparación con algoritmos muy conocidos y muy contrastados dentro del campo de los algoritmos evolutivos. El tercer artículo se centra en la modelización y resolución de un problema multiobjetivo obtenido a partir del análisis econométrico de datos referidos al rendimiento académico y satisfacción de los estudiantes andaluces con diferentes aspectos del proceso enseñanza-aprendizaje en los colegios de secundaria. Con los resultados obtenidos y teniendo en cuenta los algoritmos considerados, aunque los frentes óptimos de Pareto aproximados por A-GWASF-GA no sean los mejores en todos los casos (especialmente para los problemas con tres funciones objetivo), podemos asegurar que el nuevo algoritmo algoritmo evolutivo aquí propuesto (A-GWASF-GA) muestra resultados muy prometedores en problemas con más de tres funciones objetivo. De esta forma, A-GWASF-GA se autodefine como un algoritmo para trabajar con problemas manyobjective (con más de tres objetivos)

Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing