Optimization Of Berth Allocation Problems Based On Generalized Genetic Algorithm

The integration of economy,the globalization of trade and the advancement of science-technologies provide the favorable conditions for the development of container transportation.With the increasing development of container transportation,the throughputs of the container terminals that acting as the transfer hubs are still growing. To achieve the goal of being the regional or international hub port,the competitions among the national ports become more and more fierce.To solve the problem of vessels congestion in ports,many ports began to build supporting facilities,including large container terminals,more shore container cranes and trucks.As for the berths allocation problems,on one hand,since the shorelines are non-renewable resources,it takes great costs to build the supporting facilities;on the other hand,the traditional manual berth allocation method,i.e.First Come First Service(FCFS),is still widely used in most of the ports.Therefore,it's critical to improve the berths utilization efficiency,shorten the time the ship at ports,and decrease the operation cost under the condition of limited shoreline resources.Based on the research on the berth allocation problems(BAP) at home and abroad, considering the dynamic feature of the BAP and the operability of practical operation, and combining with the actual operation situations of container terminals and the work flows on the terminal shoreline,a dynamic berth allocation model with its constraint conditions was established in order to improve the efficiency of port and minimize the total time of the vessels waiting at port.The effect that the vessels become larger and larger on the operation of the shipping companies and ports was analyzed in this study.From the point of all-win for the shipping companies and ports,the author proposed that different priorities should be provided for vessels with different sizes in the processes of berth allocation in hub ports. Based on the above,a dynamic berth allocation with priority model was established. An improved generalized genetic algorithm(GGA) was designed and used to solve the BAP model,and the effectiveness of GGA is also validated.Meanwhile,the effect of whether adopting berthing priority factor or not on the hub ports was also analyzed. At last,the simulation example result shows that the GGA is more effective than the simple genetic algorithm(SGA) in preventing the degradation and premature convergence of the solutions;the goal that the large vessel should be considered first has been achieved in the berthing priority,which helps to solve effectively the practical operation problem that the shipping companies will ask the port for berthing in priority when the voyage dates are delayed due to some reasons such as bad weathers and so on.