| Summary: | 碩士 === 國立中正大學 === 資訊工程研究所 === 104 === The pickup and delivery problem (PDP) is an important class of routing problem that seeks to satisfy all delivery nodes with all pickup nodes through a shortest route. The selective pickup and delivery problem (SPDP) breaks the constraint to visit all pickup nodes. In the SPDP, supply is greater than demand and it seeks to satisfy all delivery nodes with some pickup nodes through a shortest route. The SPDP is more complex and flexible than the PDP. In this study, we design four heuristic operators to tackle the SPDP. The heuristic path selection guarantees the feasibility of the route. The pickup selection criterion (PSC) prevents selection of redundant pickup nodes and thus decreases the total length of the route. The inter-segment 2-opt improves intra-segment 2-opt by relaxing the limitation that the 2-opt only conduct in the same segment. The pickup rearrangement (PR) operator selects pickup nodes and repairs infeasible route. Besides we propose a delivery-first (DF) strategy that provides divide-and-conquer strategy for the SPDP; restated, it splits the problem into a delivery-first TSP and a pickup selection problem. This strategy greatly reduces the complexity to solve the SPDP. The results of experiments confirm the efficacy of the proposed method. Especially, in most test instances, the DF strategy achieves significantly shorter route in much shorter time than the state-of-the-art algorithm for the SPDP.
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