This paper deals with topological design of a hie~rchical two-levef network where the upper-level hub network is of ring type and the lower-level local access networks are of star-type. The problem is modeled as a mixed 01 integer programming, the special structure of which is exploited for the development of a dual-based lower bounding procedure. A heuristic procedure is developed to construct...

This paper presents a study on reliable single and multiple allocation hub-and-spoke network design problems where disruptions at hubs and the resulting hub unavailability can be mitigated by backup hubs and alternative routes. It builds nonlinear mixed integer programming models and presents linearized formulas. To solve those difficult problems, Lagrangian relaxation and Branch-and-Bound meth...

The goals of hub location problems are finding the location of hub facilities and determining the allocation of non-hub nodes to these located hubs. In this work, we discuss the multi-modal single allocation capacitated p-hub covering problem over fully interconnected hub networks. Therefore, we provide a formulation to this end. The purpose of our model is to find the location of hubs and the ...

These papers are produced by Cambridge Judge Business School, University of Cambridge. They are circulated for discussion purposes only. Their contents should be considered preliminary and are not to be quoted without the authors' permission. The stochastic uncapacitated single allocation p-hub center problem is an extension of the deter-ministic version which aims to minimize the longest origi...

In the facility location problem usually reducing total transferring cost and time are common objectives. Designing of a network with hub facilities can improve network efficiency. In this study a new model is presented for P-hub covering location problem. In the p-hub covering problem it is attempted to locate hubs and allocate customers to established hubs while allocated nodes to hubs are in...

In this paper, we give the rst constant-approximations for a number of layered network design problems. We begin by modeling hierarchical caching, where caches are placed in layers and each layer satis es a xed percentage of the demand (bounded miss rates). We present a constant approximation to the minimum total cost of placing the caches and routing demand through the layers. We extend this m...

in this paper, we study the problem of integrated capacitated hub location problem and seat inventory control considering concept and techniques of revenue management. we consider an airline company maximizes its revenue by utilizing the best network topology and providing proper booking limits for all itineraries and fare classes. the transportation system arises in the form of a star/star net...

Hubs, or central trans-shipment facilities, allow the construction of a network where large numbers of direct connections can be replaced with fewer, indirect connections. Hub-andspoke configurations reduce and simplify network construction costs, centralize commodity handling and sorting, and allow carriers to take advantage of scale economies through consolidation of flows. Such networks have...

Network inference deals with the reconstruction of biological networks from experimental data. A variety of different reverse engineering techniques are available; they differ in the underlying assumptions and mathematical models used. One common problem for all approaches stems from the complexity of the task, due to the combinatorial explosion of different network topologies for increasing ne...