关键词: 网格, 归档集, ε支配, δ支配, 虚拟“最优点”, 网格存优策略, δ-MOEA, ,

Abstract: Grid-based measure is commonly used to maintain diversity in many MOEAs.The ε-MOEA，which is based on the ε-dominance concept，is essentially based on grid-strategy.Though often gaining an appropriate tradeoff between the aspects of the performance，the ε-MOEA has its inherent vice and behaves unacceptably sometimes.That is，when the slope to one dimension of the PF_true changes a lot along it，the algorithm loses many extreme or representative individuals，which has a severely influence on the diversity of the solution set.In order to solve this problem，a new δ-dominance concept and suppositional optimum point concept is defined，then a new grid-based elitist-reserving strategy is proposed，finally it is applied in an EMO archive algorithm（δ-MOEA）.The experimental results illustrate δ-MOEA’s good performance，which is much better especially at the diversity than NSGA2 and ε-MOEA.

Key words: grid, archive set, ε-dominance, δ-dominance, suppositional optimum point, grid-based elitist-reserving strategy, δ-MOEA