This paper is a study of an application-based model in profit-maximizing multi-vehicle pickup and delivery selection problem (PPDSP). The graph-theoretic model proposed by existing studies of PPDSP is based on transport requests to define the corresponding nodes (i.e., each request corresponds to a pickup node and a delivery node). In practice, however, there are probably multiple requests coming from or going to an identical location. Considering the road networks with the integratable nodes as above, we define a new model based on the integrated nodes for the corresponding PPDSP and propose a novel mixed-integer formulation. In comparative experiments with the existing formulation, as the number of integratable nodes increases, our method has a clear advantage in terms of the number of variables as well as the number of constraints required in the generated instances, and the accuracy of the optimized solution obtained within a given time.
翻译:本文是对利润最大化多车辆取货和交货选择问题应用模型的研究。PPDSP现有研究提出的图形理论模型基于运输请求,以界定相应的节点(即每项请求对应一个接合节点和交货节点),但在实践中,可能有许多来自或来自同一地点的请求。考虑到公路网络与上述可喜节点,我们根据相应的PPDSP综合节点确定了一个新的模式,并提出了新的混合整数配法。在与现有配方进行比较实验时,随着可喜节点数目的增加,我们的方法在变量数量、生成案例所需的限制数量以及特定时间内获得的优化解决方案的准确性方面有着明显的优势。