Routing and Scheduling on a Shoreline with Release Times
研究一类具有释放时间约束的海岸线单车辆路径与调度问题，分析其计算复杂性，并开发精确算法（直线情形）和启发式算法（海岸线情形），适用于货运船舶等运输场景。
In this paper we examine computational complexity issues and develop algorithms for a class of “shoreline” single-vehicle routing and scheduling problems with release time constraints. Problems in this class are interesting for both practical and theoretical reasons. From a practical perspective, these problems arise in several transportation environments. For instance, in the routing and scheduling of cargo ships, the routing structure is “easy” because the ports to be visited are usually located along a shoreline. However, because release times of cargoes at ports generally complicate the routing structure, the combined routing and scheduling problem is nontrivial. For the straight-line case (a restriction of the shoreline case), our analysis shows that the problem of minimizing the maximum completion time can be solved exactly in quadratic time by dynamic programming. For the shoreline case we develop and analyze heuristic algorithms. We derive data-dependent worst-case performance ratios for these heuristics that are bounded by constant. We also discuss how these algorithms perform on practical data.