论文标题
行进小偷问题的动态多目标优化
Dynamic Multi-objective Optimization of the Travelling Thief Problem
论文作者
论文摘要
对反映现实情况的详细且复杂的优化问题制定的调查是一个新兴的研究领域。对于旅行小偷问题,存在越来越多的工作,包括多目标配方以及解决该问题的精确和近似方法的比较。但是,由于许多现实的场景在时间上是非静态的,因此TTP尚未考虑动态表述。解决了TTP问题三个领域内动态的定义;在城市位置,可用性图和项目值。基于阐明初始集合和获得的非主导集之间的解决方案保护,我们使用通过求解器生成的解决方案来定义一系列初始化机制,该机制是贪婪和随机的。然后将这些部署在变化后,以种植人口,并在超量和差异方面的性能进行比较。在不同的TSP组件和KP组件大小的各种问题中,我们观察到有趣的趋势,符合现有结论。当可以利用最佳TSP和KP组件解决方案时,将随机化作为初始化的策略几乎没有好处。尽管这些独立的Optima并不能保证合并后的良好TTP解决方案提供更好的初始性能,因此在某些检查的实例中为动态变化提供了最佳响应。一种将解决方案生成方法混合以响应动态变化提供复合种群的组合方法可在某些情况下为不同的动态TTP配方提供改善的性能。实现了进一步开发更合作的合并方法的潜力,可以更加凝聚力利用有关这些问题的已知信息。
Investigation of detailed and complex optimisation problem formulations that reflect realistic scenarios is a burgeoning field of research. A growing body of work exists for the Travelling Thief Problem, including multi-objective formulations and comparisons of exact and approximate methods to solve it. However, as many realistic scenarios are non-static in time, dynamic formulations have yet to be considered for the TTP. Definition of dynamics within three areas of the TTP problem are addressed; in the city locations, availability map and item values. Based on the elucidation of solution conservation between initial sets and obtained non-dominated sets, we define a range of initialisation mechanisms using solutions generated via solvers, greedily and randomly. These are then deployed to seed the population after a change and the performance in terms of hypervolume and spread is presented for comparison. Across a range of problems with varying TSP-component and KP-component sizes, we observe interesting trends in line with existing conclusions; there is little benefit to using randomisation as a strategy for initialisation of solution populations when the optimal TSP and KP component solutions can be exploited. Whilst these separate optima don't guarantee good TTP solutions, when combined, provide better initial performance and therefore in some examined instances, provides the best response to dynamic changes. A combined approach that mixes solution generation methods to provide a composite population in response to dynamic changes provides improved performance in some instances for the different dynamic TTP formulations. Potential for further development of a more cooperative combined method are realised to more cohesively exploit known information about the problems.