This paper proposes a new lower bounding procedure for the Uncapacitated Single Allocation p-Hub Median Problem based on Lagrangean relaxation. For solving the resulting Lagrangean subproblem, the given problem structure is exploited: it can be decomposed into smaller subproblems that can be solved efficiently by combinatorial algorithms. Our computational experiments for some benchmark instanc...

The return-to-origin probability and the first-passage-time distribution are essential quantities for understanding transport phenomena in diverse systems. The behaviors of these quantities typically depend on the spectral dimension d(s). However, it was recently revealed that in scale-free networks these quantities show a crossover between two power-law regimes characterized by d(s) and the so...

A geography-based grid location service (GLS), proposed elsewhere, has resulted in a scalable location management service for mobile ad hoc networks (MANETs) where packet forwarding decisions are based on geographic position. A similarly scalable location management strategy has been devised for MANETs that employ hierarchical link state routing. Both approaches employ hierarchical principles ...

This paper developed a mathematical model framework using the single allocation strategy for hub covering location problem. The model encompassed the transportation time covering under gradual decay function. Within a certain transportation time for the origin and destination nodes among two hubs, the route is fully covered, and beyond another specified transportation time the route is not cove...

The localization abilities of smartphones have provided a huge boost to the popularity of geosocial applications, which facilitate social interaction between users geographically close to each other. However, today’s geosocial applications raise privacy concerns due to application providers storing large amounts of information about users (e.g., profile information) and locations (e.g., users p...

Available online 9 December 2008

This paper describes an exact algorithm capable of solving large-scale instances of an important hub location problem called the Uncapacitated Hub Location Problem with Multiple Assignments. The algorithm applies Benders decomposition to a strong path-based formulation of the problem. The standard decomposition algorithm is enhanced through the inclusion of several features such as the use of a...

Two competitors, a Leader and a Follower, are sequentially creating their hub and spoke networks to attract customers in a market where prices have fixed markups. Each competitor wants to maximize his profit, rather than a market share. Demand is split according to the logit model. The goal is to find the optimal hub and spoke topology for the Leader. We represent this Stackelberg game as a non...