@techreport{oai:ipsj.ixsq.nii.ac.jp:00217766,
 author = {Tetsuo, Asano and Tetsuo, Asano},
 issue = {3},
 month = {May},
 note = {We consider a transportation problem defined on a node-weighted undirected graph. Weight is positive if the amount of commodity is stored at a node, and negative if the amount is needed at the node. We want to meet all demands by transporting commodities using vehicles prepared either at nodes or edges which only travel to and from neighbors. In a trip from a node to a neighbor we can send commodities and also bring back some other commodities. Problem is to decide whether we can meet all demands by carrying out a set of trips in a few rounds. We define three different schemes to solve the problem and examine their performances. We present a polynomial-time algorithm for deciding whether there is a single round of trips using one vehicle at each node that meet all demands for one-commodity case. Although extension to multi-commodity case is unknown, we can also extend it to multiple rounds as far as the number of iterations is bounded by a constant., We consider a transportation problem defined on a node-weighted undirected graph. Weight is positive if the amount of commodity is stored at a node, and negative if the amount is needed at the node. We want to meet all demands by transporting commodities using vehicles prepared either at nodes or edges which only travel to and from neighbors. In a trip from a node to a neighbor we can send commodities and also bring back some other commodities. Problem is to decide whether we can meet all demands by carrying out a set of trips in a few rounds. We define three different schemes to solve the problem and examine their performances. We present a polynomial-time algorithm for deciding whether there is a single round of trips using one vehicle at each node that meet all demands for one-commodity case. Although extension to multi-commodity case is unknown, we can also extend it to multiple rounds as far as the number of iterations is bounded by a constant.},
 title = {Transportation Problem on a Graph},
 year = {2022}
}