Distance-Based Analysis of Crossover Operators for Many-Objective Knapsack Problems
Distance-Based Analysis of Crossover Operators for Many-Objective Knapsack Problems
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DOI:
10.1007/978-3-319-10762-2_59
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发表时间:
2014-09
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影响因子:
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通讯作者:
H. Ishibuchi;Yuki Tanigaki;Hiroyuki Masuda;Y. Nojima
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文献类型:
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作者:
H. Ishibuchi;Yuki Tanigaki;Hiroyuki Masuda;Y. Nojima
It has been reported for multi-objective knapsack problems that the recombination of similar parents often improves the performance of evolutionary multi-objective optimization (EMO) algorithms. Recently performance improvement was also reported by exchanging only a small number of genes between two parents (i.e., crossover with a very small gene exchange probability) without choosing similar parents. In this paper, we examine these performance improvement schemes through computational experiments where NSGA-II is applied to 500-item knapsack problems with 2-10 objectives. We measure the parent-parent distance and the parent-offspring distance in computational experiments. Clear performance improvement is observed when the parent-offspring distance is small. To further examine this observation, we implement a distance-based crossover operator where the parent-offspring distance is specified as a user-defined parameter. Performance of NSGA-II is examined for various parameter values. Experimental results show that an appropriate parameter value (parent-offspring distance) is surprisingly small. It is also shown that a very small parameter value is beneficial for diversity maintenance.