A decomposition-based hybrid multiobjective evolutionary algorithm with dynamic resource allocation

Different crossover operators suit different problems. It is, therefore, potentially problematic to chose the ideal crossover operator in an evolutionary optimization scheme. Using multiple crossover operators could be an effective way to address this issue. This paper reports on the implementation of this idea, i.e. the use of two crossover operators in a decomposition-based multi-objective evolutionary algorithm, but not simultaneously. After each cycle, the operator which has helped produce the better offspring is rewarded. This means that the overall algorithm uses a dynamic resource allocation to reward the better of the crossover operators in the optimization process. The operators used are the Simplex Crossover operator (SPX) and the Center of Mass Crossover operator (CMX). We report experimental results that show that this innovative use of two crossover operators improves the algorithm performance on standard test problems. Results on the sensitivity of the suggested algorithm to key parameters such as population size, neighborhood size and maximum number of solutions to be altered for a given subproblem in the the decomposition process are also included.

The hybrid algorithm MOEA/D-DRA-CMX+SPX does as well as the better of the two single-operator versions, MOEA/D-DRA-CMX. This means that the hybrid removes the risk of choosing the non-suitable crossover operator. Figure optionsDownload as PowerPoint slideHighlights
► The algorithm uses decomposition to handle the approximation to the PF of the overall problem.
► It also uses two different crossover operators to generate new solutions; hence the hybridisation idea.
► The two operators compete for resources; this is achieved through a dynamic resource allocation.
► Standard benchmark problems, the CEC’09 test set, have been used for testing.
► Performance results based on the IGD metric show that the hybrid algorithm is overall superior to versions with single crossover operators.