Using covering problems (CoP) combined with binary search is a well-known and successful solution approach for solving continuous center problems. In this paper, we show that this is also true for center hub location problems in networks. We introduce and compare various formulations for hub covering problems (HCoP) and analyse the feasibility polyhedron of the most promising one. Computational...

In this paper, a new priority M/M/c queuing hub covering problem is presented, in which products with high priority are selected for service ahead of those with low priority. In addition, a mixed-integer nonlinear mathematical programming model is presented to find a good solution of the given problem. Due to its computational complexity, we propose a multi-objective parallel simulated annealin...

The use of graph databases for social networks, images, web links, pathways and so on, has been increasing at a fast pace and promotes the need for efficient graph query processing on such databases. In this study, we discuss graph query processing – referred to as graph matching – and an inherent optimization problem known as the minimum hub cover problem. This optimization problem is introduc...

the existing works considering the flow-based discount factor in the hub and spoke problems, assume that increasing the amount of flow passing through each edge of network continuously decreases the unit flow transportation cost. although a higher volume of flow allows for using wider links and consequently cheaper transportation, but the unit of flow enjoys more discounts, quite like replacing...

Article history: Received 10 August 2012 Received in revised format 14 September 2012 Accepted September 27 2012 Available online 28 September 2012 The hub location problem involves a network of origins and destinations over which transportation takes place. There are many studies associated with finding the location of hub nodes and the allocation of demand nodes to these located hub nodes to ...

This paper focuses on a hub reentrant shop scheduling problem which is motivated by actual packing production line in the iron and steel industry. There are five operations for processing a job where three operations must be processed on a hub machine, and between any two consecutive operations on the hub machine, two operations must be processed on other two secondary machines, respectively. W...