Research On Dynamic Slot Allocation Strategy Optimization In Container Terminal Yards

The promotion of container transportation and larger and larger container ships has made the efficiency of container terminals the bottle-neck of container transportation. And how to develop the operation efficiency of container terminals has been an important subject of many countries and researchers in order to face the new situation. Many existed container terminals are carrying operation loads that exceed their capacity, and especially container yard space seems to be too few relatively, which makes container yard as the bottle-neck of container terminals. So it is of much significance to research operations in container yards. While operation strategy in container yards can be divided into two stages, that is, block allocation strategy and special slot allocation strategy, which are both studied in this dissertation.Firstly, a mathematic model is established for the progress of containers entering into container yards, where a heuristic algorithm for generating pulling/re-stacking decisions is given, using graph theory. An expression form of stack strategy also is given, and the stack strategy is optimized by simulated annealing algorithm combined with simulation, aimed to reduction of re-stacking times.Secondly, based on the allocation progress of container flow among blocks, the block allocation strategy is divided into two stages, that is, model of operation amount balance among blocks and model of minimizing distance between blocks and berths. The constraint of the two stages is analyzed and better strategies are developed by heuristic algorithms.Then, using Witness platform, function modules are separated from container terminals, based on characteristics of its operation. Then structure and units of simulation model is designed according to these modules, which specifies the simulation model onto the allocation of slots.Finally, a specific terminal is taken as object, which is applied the traditional strategies and the strategies given in this dissertation. And the performance is studied by comparing the simulation results.