基于改进NSGA-II算法的班轮船期恢复双目标优化

A bi-objective optimization for liner schedule recovery based on improved NSGA-II

针对班轮延误后船期恢复问题,采用调整速度、取消挂靠港和缩短在港时间三种船期恢复措施,综合考虑班轮公司经济效益与货主满意度,引入模糊时间窗,将货主满意度量化为班轮延误时间的模糊隶属度函数,构建以班轮运营成本最小和货主满意度最大的双目标优化模型;设计嵌套正交搜索策略的改进NSGA-II算法,求出满足班轮公司和货主双方需求的Pareto非劣解集合.最后,以具体算例验证了模型的有效性和改进的算法的优越性.结果表明,该模型和算法能够为班轮公司在不同市场环境下提供决策参考.

In view of the liner schedule recovery problem after the delay, three recovery measures were adopted, including adjusting the speed, canceling the port of call and shortening the time in port. Taking into account of the economic benefits of liner companies and the shippers’ satisfaction, the fuzzy time window was introduced to quantify the shippers’ satisfaction as a fuzzy membership function of liner delay time, and a bi-objective model with minimum liner operation cost and the maximum owner satisfaction was established. An improved NSGA-II algorithm nested orthogonal search strategy was designed to find the Pareto-front non-inferior solution set which meet the needs of both liner companies and shippers. Finally, a practical example was used to verify the effectiveness of the model and the superiority of the improved algorithm. The results show that the model and algorithm can provide a decision-making reference for liner companies in different market conditions.