In this article, we consider the set covering problem with conflict constraints, i.e., from each conflicting pair of columns at most one column can appear in feasible solution. For problem, propose appropriate pre-processing techniques and several families Valid Inequalities (VIs) for corresponding integer programming model that result simultaneous presence constraints stable (conflict) constra...

 We introduce a dynamic and stochastic transportation problem consisting of two subproblems. For parcel transportation in hub-and-spoke networks, swap containers are used to carry out hub-to-hub shipments. This constitutes a pickup and delivery problem on the operational level. On the tactical level, empty swap containers are balanced over the hub-network in order to match the stochastic deman...

The biggest challenges faced in big cities are greenhouse gas emission and growing energy needs. Efficient utilization of existing infrastructures has a prominent role in response to the challenges. Energy hub approach embraces performance of different energy networks. Energy hub is defined as a super node in electrical system receiving distinctive energy carriers such as gas and electricity in...

Covering Tour Problem (CTP) is the generalized form of Traveling Salesman Problem (TSP), which has found different applications in the designing of distribution networks, disaster relief, and transportation routing. The purpose of this problem is to determine the Hamiltoniancyclewiththe lowest costusinga subset of all the nodes, such that the other nodes would be in a distance shorter than the ...

This paper considers the discrete two-hub location problem. We need to choose two hubs from a set of nodes. The remaining nodes are to be connected to one of the two hubs which act as switching points for intemodal flows. A configuration which minimizes the total flow cost needs to be found. We show that the problem can be solved in polynomial dme when the hub locations are fixed. Since there a...