考虑运输时限和航速优化的班轮航线网络设计

为了保持市场竞争能力，班轮公司需要保证集装箱在各个港口间的运输时间达到市场平均水平. 本研究将航速设为变量，对具有运输时限的班轮航线网络设计问题进行求解，以得到既满足运输时限要求又能最大化总利润的航线网络设计与配船方案. 为了有效求解实际问题，首先采用港口聚类算法筛选出候选挂靠港，然后确定港口的标号顺序，最后采用基于列生成思想的启发式算法对问题的非线性混合整数规划模型进行分解和迭代求解. 采用不同规模的标准算例，验证了模型和算法的有效性. 结果表明，与采用事先给定的设计航速相比，将航速设为变量，对每条航线的平均航速进行优化，能增强航线网络设计的灵活性并提升航线网络的盈利能力.

Liner Service Network Design with Transit Time Constraints and Speed Optimization

To upgrade the profitability to a competitive level, the liner companies need to ensure that their container transit time between origin- destination ports would not exceed the market level. In order to satisfy customer demands and maximize the total profit for the whole shipping network, this paper takes the ship speeds as variables, and proposes a container liner shipping network design problem with transit time limits. To effectively solve the practical problem, firstly, a port clustering algorithm is used to select the main candidate ports. Then, the ports index sequence is determined by considering their geography position. Lastly, a column generation based heuristic algorithm is proposed to decompose and solve the model to obtain the final network solution. The algorithms are tested on benchmark instances with different problem sizes. Experimental results show that when taking ship speeds as variable rather than a fixed input, both the profit and flexibility of shipping network can be improved significantly.