수송문제를 활용한 공화차 배분 최적화 모형

초록

Recently, in the rail freight transportation, the number of the dedicated trains to the shippers has been increasing. The dedicated trains, which mean are run by the contract with shipper, had been restricted to transporting containers, so called block trains. Nowadays such a commodity is extended to cement, hard coal and etc. Most amounts of full freight cars are transported by the dedicated trains. But for empty car distribution, its efficiency still remains questionable because the distribution plan is being manually developed by dispatchers. In this study, we investigated the distribution models stated in the KTOCS system which was developed by KORAIL but now is not being used as well as in the state-of-the-art. The models are based on the optimization model, especially network flow model. Here we suggest a new optimization model with the framework of column generation approach. The master problem can be formulated into transportation problem with additional constraints. The master problem is improved by adding a new edge between the supply node and demand node, which could be found by a simple shorted path in the time-space network.