Given a directed network, the uncapacitated fixed-charge network flow problem is to find a minimum-cost arc combination that provides flows from the supply nodes to the demand nodes. Associated with all arcs are two costs: the fixed charge of using the arc and the variable cost depending on the amount of flow the arc actually carries. This generic model has applications for problems of distribu...

We propose routing algorithms for plug-in hybrid electric vehicles (PHEVs) that account for the significant energy efficiency differences of vehicle operating modes and recommend the predominant mode of operation for each road segment during route planning. This is to enhance fuel economy and reduce emissions. We introduce the Energy-Efficient Routing problem (EERP) for PHEVs, and formulate thi...

Distance labelings and compact routing schemes have both been active areas of recent research. It was already known that graphs with constant-sized recursive separators, such as trees, outerplanar graphs, series-parallel graphs and graphs of bounded treewidth, support both exact distance labelings and optimal (additive stretch 0, multiplicative stretch 1) compact routing schemes, but there are ...

Consider a communication network G in which a limited number of edge(arc) and/or vertex faults F might occur. A routing ρ, i.e. a fixed path between each pair of vertices, for the network must be chosen without knowing which components might become faulty. The diameter of the surviving route graph R(G, ρ)/F , where R(G, ρ)/F is a digraph with the same vertices as G − F and a vertex x being adja...

The Prize-collecting Rural Postman Problem, also known as the Privatized Rural Postman Problem, is an arc-routing problem where each demand edge is associated with a profit, which is collected once if the edge is served, independently of the number of traversals. Included edges incur in routing costs proportionally to the number of traversals. In this paper, we introduce the Windy Privatized Ru...

Hazardous materials routing and scheduling decisions involve the determination of the minimum cost and/or risk routes for servicing the demand of a given set of customers. This paper addresses the bicriterion routing and scheduling problem arising in hazardous materials distribution planning. Under the assumption that the cost and risk attributes of each arc of the underlying transportation net...

The capacitated arc routing problem (CARP) is one of the most important routing problems with many applications in real world situations. In some real applications such as urban waste collection and etc., decision makers have to consider more than one objective and investigate the problem under uncertain situations where required edges have demand for more than one type of commodity. So, in thi...