废弃物处理设施是典型的“Semi—desirable”设施,其选址相关的决策需要考虑成本、负效应等多个相互冲突的目标.废弃物中转站的选址和路径优化是一类周期性选址一路径问题(PLRP),目前缺乏对这类问题的多目标优化的研究.以多目标城市废弃物收运网络周期性选址一路径问题为研究对象,提出基于扩散距离的负效应测度方法;建立考虑负效应和成本的双目标混合整数规划模型;设计DRECWA—LS算法,结合启发式优化策略,求解收运计划对应的周期性选址一路径问题,并采用扩展邻域搜索策略的多目标进化算法实现对可行收运计划的深度搜索,同步求解收运计划、中转站选址一分配及车辆路径三个问题.算例结果显示:算法能成功求解较大规模问题,具有较高的求解质量和运算效率.
Waste disposal facilities are kinds of typical "semi-desirable facilities". Some incompatible objectives such as cost and obnoxious effect etc. should be considered in the process of location and other related decisions of these facilities. The location-routing problem in waste logistics network in cities is one kind of typical periodic location routing problem (PLRP), for different population centers can be visited by different frequency in certain period, however, the multi-objective optimization of this problem is short of research. A multi-objective PLRP is studied in this paper, which combines the practical situation of waste logistics network in cities. A new method is proposed measuring negative effect based on the concept of dispersion distance; a mixed integer programming model concerning two objectives of average total cost and average negative effect is raised; a multi-objective evolutionary algorithm is devised to solve location- allocation problem, visiting scheduling problem and vehicle routing problem simultaneously. The global algorithm strengthens an extension local search deepening the search of feasible collection and transporta- tion plans; a sub-algorithm termed DRECW-LS which strengthens the diversification, randomization and local search based on ECWA solves the periodic location-routing problem. The computing example shows: the algorithm can solve analogous large size problems and shows excellent quality and computing efficiency.