Study On Optimization Of Slot Plan Problem Considering Container Reloading Operations At Yard

The stowage planing is an important factor that affects the competitiveness of container transportation.The stowage planing includes two aspects: slot planing and container ship loading sequencing.Most of the existing researches focus on one of these problems,but few scholars consider the coordinated optimization of the ship and the yard.If we consider these two problems separately,we can't get the reasonable slot plan and container ship loading sequence at the same time,which will result in reloading operations of the yard or the container ship.Therefore,this paper studied the coordinated optimization problem of slot planning and shipment sequencing.On one hand,considering the constraints of the ship,the position of the container in the bay is determined with the goal of reducing the reloading operations in ship.On the other hand,considering the storage of containers in the yard,the reasonable ship loading sequence is determined with the goal of reducing the reloading operations in yard.Firstly,this thesis studied the slot plan problem.To ensure the rolling moment constraint,this thesis proposed three different shipping rules and inmpoved the evolutionary strategy algorithm.By comparing the solution results of the evolutionary strategy algorithm under different shipping rules,the best shipping rule was selected to embed the algorithm for ensure the rolling moment constraint.Finally,several different algorithms were used to solve the example.Through the comparison,the effectiveness and superiority of the evolutionary strategy algorithm were proved.The optimal loading rule and algorithm selected in this part also lay the foundation for the comprehensive optimization of yard and container ship.On the basis of the slot plan problem,this thesis further studied the coordinated optimization problem of the container ship and the yard.Firstly,a mathematical model was established with the goal of minimizing the reloading operation times of the yard and the ship.Besides,the heuristic rule and the hybrid evolutionary strategy algorithm were designed for the model.Then,the single bay stowage problem of container ship considering reloading operations in yard and the multi bay stowage problem of container ship considering reloading operations in yard were solved by designing examples.Finally,the effectiveness of the hybrid evolutionary strategy algorithm was verified by comparing the results of those different algorithms.The results of this thesis showed that the proposed rules could effectively guarantee the rolling moment constraints of the slot plan problem,and the hybrid evolutionary strategy algorithm could effectively solve the coordinated optimization problem of the container ship and the yard.The research results could provide some reference value for the similar research,and provide some decision support for the actual operation of the terminal.