Integrated Logistic Scheduling Research Of Ship Unloading And Stockpiling

During the development of modern logistics, port has continued to highlight its role in international trades and logistics, its commercialization trend is further enhanced, port logistics have become an important area in the development of modern logistics, so study of the port logistics scheduling is of great significance to ports.This dissertation focuses on integrated logistics scheduling of ship unloading and goods stockpiling problem, and studies how to arrange reasonable stockpiling of goods when the goods are unloading in the same time with a large amounts in the ports, and how to use its limited resources to stack a great number of items so as to make the ship service time as short as possible and at the same time guarantee the balance of each stockpiling area working capacity. The detailed contents of this dissertation are given as follows:1)Study on the integrated scheduling of goods unloading and stockpiling after ships’ arrival in oil ports. With the assumption that the unloading order of ships is known, the conveying constraints of each tanker of the ship to the terminal tank at the port are analyzed. Taking into consideration of the switching time of tanks, a mixed integer programming model is formulated for this problem, whose objective is to minimize the ship’s unloading time, and the distance and cost of the oil transmission.2)Using differential evolution algorithm to solve the proposed MILP model. The differential evolution algorithm is fast and it has a good ability of getting out of local optimum, and thus very suitable for solving complex problems. The results of the computational experiments illustrate its efficiency. This algorithm is embedded into the oil port logistics scheduling system to obtain the optimal arrangement of each tank.3)Study on the stockpiling scheduling problems of containers after the ship is berthed in the container terminal. The objective is to minimize the total container transport distances and consumption costs of the same cargo containers. Taking into consideration of the constraint of amounts balance of the same type containers in each stockpiling area among the total stockpiling areas, whose aim is to avoid cranes waiting trucks case occur when the type of containers moving out of one stockpiling area, an integer programming model is proposed for this problem.4)The differential evolution algorithm and standard solution software are used to solve the proposed integer programming model, respectively. The comparison results show that the differential evolution algorithm has better performance in the solving speed for large-scale problems. During the developing process of the container logistics scheduling system, the differential evolution algorithm is embedded in the unloading and stockpiling scheduling module so that the system can have a good ability of adapting to environmental changes and thus is more robust.