摘要: |
The Los Angeles/Long Beach (LA/LB) port complex is the intermodal gateway to Pacific Rim trade and the busiest container port complex in the United States. Comprising of fourteen individually gated terminals, during 1999 alone, the combined ports handled 8.2 million 20-foot equivalent units (TEUs) containers. This figure implies that almost 4.43 million full containers were handled during 1999 in the LA/LB port complex (at the rate of 1.85 TEU/container). Usually the arriving loaded containers at ports are picked up and transported by trucks to their destinations. Having been unloaded at the importers, the emptied containers are returned to the port. At the same time, empties are picked up by trucks from the ports and brought to the export firms, where they are loaded with export goods. The loaded containers are then transported to the port to be loaded on the ship for export. In this procedure the empty containers are handled twice at marine terminals i.e. the first time when they are recycled from importers, and the second time when they are trucked to exporters. It is clear that a system, which facilitates the interchange of empties outside the ports, is not only desirable but also necessary. This system will reduce the truck trips to and from container terminals, and as a consequence, will reduce the traffic congestion around the ports. In addition to saving time for both truckers and port operators, the system will significantly reduce noise and emissions around container terminals. In this report, the empty container interchange problem is investigated in both deterministic and stochastic transportation environments. In stochastic networks the problem is modeled analytically and optimization techniques are developed. In deterministic environments, the empty container substitution problem, in which the request of one type of containers could be fulfilled with another type, is investigated. The simulation experiments are used to demonstrate the efficiency of the developed optimization techniques and approach. |