— We use panel data consisting of 96 countries and covering the period 1960–2000 to investigate the effects of free trade agreements (FTAs) and hub-and-spoke systems of FTA on exports. Our empirical results imply an annual growth rate of 5.57% in exports and hence a doubling of exports after 12.4 years between FTA partners. Non-overlapping FTAs account for 4.12%, while hub-andspoke FTAs account...

The hub location problem deals with finding the location of hub facilities and allocating the demand nodes to these hub facilities so as to effectively route the demand between any origin–destination pair. In the extensive literature on this challenging network design problem, it has widely been assumed that the subgraph induced by the hub nodes is complete. Relaxation of this basic assumption ...

Hubs are centers for collection, rearrangement, and redistribution of commodities in transportation networks. In this paper, non-linear multi-objective formulations for single and multiple allocation hub maximal covering problems as well as the linearized versions are proposed. The formulations substantially mitigate complexity of the existing models due to the fewer number of constraints and v...

We consider the capacitated square covering problem (CSCP), which is described as follows. Given a set of points, each having a demand, in the two-dimensional Euclidean plane, we find the minimum number of squares with the same size and capacity to cover all the points under the capacity constraint. As CSCP is NP-hard, we focus on heuristic algorithms in this paper. We first test a set covering...

Multi-objective capacitated multiple allocation hub location problem (MOCMAHLP) is a variation of classic problem, which deals with network design, considering both the number and hubs connections between spokes, as well routing flow on network. In this study, we offer two meta-heuristic approaches based non-dominated sorting genetic algorithm (NSGA-II) archived multi-objective simulated anneal...

In this work, we introduce the Cov-MECF framework, a special case of minimum-edge cost flow in which the input graph is bipartite. We observe that several important covering (and multi-covering) problems are captured in this unifying model and introduce a new heuristic LPO for any problem in this framework. The essence of LPO harnesses as an oracle the fractional solution in deciding how to gre...