| For the shipping enterprises operating container domestic trade liner,the punctuality rate of the route is very important.However,due to unpredictable weather,channel traffic accidents,port equipment failures and other emergencies,port interruptions occur frequently.It has a great impact on the transportation services of liner routes,which may not only cause ships to be forced to stay in interrupted ports,but also cause chain off shifts on liner routes,resulting in great losses to customers and shipping enterprises.Therefore,how to deal with the impact of port interruption and carry out emergency dispatching of operating ships on liner routes in time and effectively is one of the hot issues that shipping enterprises focus on at present.Based on the established liner shipping schedule and multi-port transportation network,this thesis studies the liner ship emergency scheduling problem considering the influence of port disruption.Firstly,at the beginning of a fixed plan period,the capacity,economic speed and freight demand of each liner route of all operating ships the company owned on the network are known,as well as the established shipping schedule published in advance;In view of the uncertainty of the impact of port service disruption on ship scheduling plan,taking into account the limitation of the cargo time window and the rated load of the liner ship,a nonlinear mathematical model is constructed with the optimization goal of minimizing the total operating cost of the liner ship during the fixed planning period.Then,according to the characteristics of the established model,the corresponding applicable improved genetic algorithm is designed to solve this problem.In this improved algorithm,the chromosome coding of multi-layer dyeing mixture is used,the fitness list is generated,the elite strategy is used to select the offspring,the interrupt factor is embedded,and the large neighborhood search operator is integrated at the same time.Finally,a comparative experiment of different scale examples is set up to verify the effectiveness of the model and scheme;Comparing the target value obtained by the experiment with the lower bound and the target value obtained by Tabu search algorithm and ant colony algorithm,the results can verify the scientificity of the algorithm in this thesis;Meanwhile,sensitivity analysis experiments are also carried out on the length of port interruption and the location of port interruption.The results show that through the systematic analysis of different port interruption scenarios and the ship emergency scheduling scheme with the strategies of timely adjusting the speed,timely dumping and coupling and chartering as the core,the freight demand of liner routes can be met with the minimum scheduling cost,and the overall decision support can be provided for the shipping enterprises operating domestic liner routes. |
