Meng Weiyue, Li Guorong, Hua Lianlian
School of Statistics, Jilin University of Finance and Economics, Changchun, 130117, China.
School of Economics and Management, Inner Mongolia University of Technology, Hohhot, 010021, China.
Ocean Coast Manag. 2022 Jun 15;225:106222. doi: 10.1016/j.ocecoaman.2022.106222. Epub 2022 May 23.
The Covid-19 epidemic, has caused a large-scale congestion in many ports around the world. This increases the cost of port docking, as well as delays the loading and unloading of goods, which affects the price and timely supply of many products. Although scholars have carried out in-depth discussion and analysis on the port congestion problem from different perspectives, there is still no appropriate model and algorithm for the large-scale comprehensive port docking problem. This paper presents a new mixed integer programming model for optimal docking of ships in ports that is comprehensive enough to include four essential objectives. It discusses the generalization and application of the model from the perspectives of the shortest overall waiting time of ships, the balance of tasks at each berth, completion of all docking tasks as soon as possible and meeting the expected berthing time of ships. We demonstrate the results of our models using relevant examples and show that our model can obtain the optimal docking scheme based on different perspectives and relevant objectives. We also show that the scale of the exact solution can reach tens of thousands of decision variables and more than a million constraints. This fully reflects the possibility that the model can be put into use in any real life scenario. This model can not only effectively improve the docking efficiency of the port, but is also suitable for the complex queuing problem of multi window and the same type of service.
新冠疫情在全球许多港口造成了大规模拥堵。这增加了港口停靠成本，还延误了货物装卸，影响了许多产品的价格和及时供应。尽管学者们已从不同角度对港口拥堵问题进行了深入讨论和分析，但对于大规模综合港口停靠问题，仍没有合适的模型和算法。本文提出了一种新的混合整数规划模型，用于港口船舶的最优停靠，该模型足够全面，包含四个基本目标。从船舶总体等待时间最短、每个泊位任务平衡、尽快完成所有停靠任务以及满足船舶预期靠泊时间等角度，讨论了该模型的通用性和应用。我们用相关示例展示了模型的结果，表明我们的模型能够基于不同角度和相关目标获得最优停靠方案。我们还表明，精确解的规模可达数万个决策变量和超过一百万个约束条件。这充分体现了该模型在任何实际场景中投入使用的可能性。该模型不仅能有效提高港口停靠效率，还适用于多窗口同类型服务的复杂排队问题。
