Design of network, through which data, packages or even people can be transported, is an important issue for achieving a desired level of service quality at an acceptable cost. For this purpose, it is possible to design a network comprised of nodes that are connected to each other with dedicated lines. However, this kind of solution will not be cost effective. In order to decrease the total tra...

In this paper, a comprehensive model for hub location-routing problem is proposed which no network structure other than connectivity is imposed on backbone (i.e. network between hub nodes) and tributary networks (i.e. networks which connect non-hub nodes to hub nodes). This model is applied in public transportation, telecommunication and banking networks. In this model locating and routing is c...

Hubs are special centers that used for switching, transferring and handling freight or passengers in transportation systems. The hub location problem deals with locating hub facilities and allocating demand nodes to hubs in order to route the traffic between origin–destination pairs. Aiming at minimizing the total costs, maximizing utilization of transporters, maximizing the service level, etc....

Hub location problems are strategic network planning problems. They formalise the challenge of mutually exchanging shipments between a large set of depots. The aim is to choose a set of hubs (out of a given set of possible hubs) and connect every depot to a hub so that the total transport costs for exchanging shipments between the depots are minimised. In classical hub location problems, the un...

Abstract Many of air cargo companies adapt the hub-and-spokes system where economies of scale exist in the transportation cost. In this paper, we formulate economies of scale using nonlinear cost function of distances and demands, and analyze how the change of the transportation cost affects single hub location of air cargo using the generalized Weber problem on the regular demand points of one...

Abstract One of the basic assumptions in hub covering problems is considering the covering radius as an exogenous parameter which cannot be controlled by the decision maker. Practically and in many real world cases with a negligible increase in costs, to increase the covering radii, it is possible to save the costs of establishing additional hub nodes. Change in problem parameters during the pl...

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...

The Single Allocation Ordered Median Hub Location problem is a recent hub model introduced in [36] that provides a unifying analysis of a wide class of hub location models. In this paper, we deal with the capacitated version of this problem, presenting two formulations as well as some preprocessing phases for fixing variables. In addition, a strengthening of one of these formulations is also st...

The problem of maximal hub covering as a challenging problem in operation research. Transportation programming seeks to find an optimal location of a set of hubs to reach maximum flow in a network. Since the main structure's parameters of the problem such as origin-destination flows, costs and travel time, change periodically in the real world applications, new issues arise in handling it. In t...