Hubs are facilities used to treat and dispatch resources in a transportation network. The main idea of Hub Location Problems (HLP) is to locate a number of hubs in a network and route resources from origins to destinations such that the total cost of attending all demands is minimized. In this study, we investigate a particular HLP, called the Tree of Hubs Location Problem in which hubs are con...

This study presents a multimodal hub location problem which has the capability to split commodities by limited-capacity hubs and transportation systems, based on the assumption that demands are stochastic for multi-commodity network flows. In the real world cases, demands are random over the planning horizon and those which are partially fulfilled, are lost. Thus, the present study handles dema...

We study stochastic uncapacitated hub location problems in which uncertainty is associated to demands and transportation costs. We show that the stochastic problems with uncertain demands or dependent transportation costs are equivalent to their associated deterministic expected value problem (EVP), in which random variables are replaced by their expectations. In the case of uncertain independe...

This paper presents a new mathematical model, in which the location of hubs is fixed and their capacity is determined based on facilities and factories allocated to it. In order to feed the client's nodes, different types of vehicles of different capacities are considered, in which the clients are allocated to hubs, and types and numbers of vehicles are allocated to the factory's facilities. To...

In this paper we propose several heuristics for the Uncapacitated -Allocation -Hub Median Problem. In the classical -hub problem, given a set of nodes with pairwise traffic demands, we must select of them as hub locations and route all traffics through them at a minimum cost. We target here an extension, called the -allocation -hub median problem, recently proposed by Yaman (2011), in which eve...

A new multi-objective intermodal hub-location-allocation problem is modeled in this paper in which both the origin and the destination hub facilities are modeled as an M/M/m queuing system. The problem is being formulated as a constrained bi-objective optimization model to minimize the total costs as well as minimizing the total system time. A small-size problem is solved on the GAMS software t...

This paper deals with a hub location-routing problem (HLRP) which integrates the hub location problem (HLP) and the multi-hub vehicle routing problem (MH-VRP) in parcel delivery service. The HLRP is very difficult to be solved since it is composed of two NP-hard problems, the HLP and the MH-VRP. To solve these problems simultaneously we present a novel solution framework which divides the probl...