an efficient cluster head selection algorithm in wireless sensor networks is proposed in this paper. the implementation of the proposed algorithm can improve energy which allows the structured representation of a network topology. according to the residual energy, number of the neighbors, and the centrality of each node, the algorithm uses fuzzy inference systems to select cluster head. the alg...

The analytic center cutting plane method (ACCPM) is one of successful methods to solve nondifferentiable optimization problems. In this paper ACCPM is used for the first time in the vehicle routing problem with time windows (VRPTW) to accelerate lagrangian relaxation procedure for the problem. At first the basic cutting plane algorithm and its relationship with column generation method is clari...

centralizing and using proper transportation facilities cut down costs and traffic. hub facilities concentrate on flows to cause economic advantage of scale and multimodal transportation helps use the advantage of another transporter. a distinctive feature of this paper is proposing a new mathematical formulation for a three-stage p-hub location routing problem with simultaneous pick-ups and de...

In this paper, we study the routing problem for the undirected binary de Bruijn interconnection network. Researchers have never proposed a shortest path routing algorithm on the undirected binary de Bruijn network. We first propose a shortest path routing algorithm, whose time complexity in the binary de Bruijn network of 2 nodes is O(m2). Then, based on our shortest path routing algorithm, we ...

In a localized routing algorithm, node A currently holding the message forwards it to one or few neighbors based on the location of itself, its neighboring nodes and destination. Several localized routing algorithms for wireless networks were described recently, based on location information of nodes available via Global Positioning System (GPS). The quality-of-service (QoS) routing (routing wi...

This paper aims to compare a two-echelon and a single-echelon distribution system. A mathematical model for the Single-Echelon Capacitated Vehicle Routing Problem (SE-CVRP) is proposed. This SE-CVRP is the counterpart of Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP) introduced in the authors’ previous work. The proposed mathematical model is Mixed-Integer Non-Linear Programming (MIN...

mobile ad hoc networks (manets) are composed of mobile stations communicating through wireless links, without any fixed backbone support. in these networks, limited power energy supply, and frequent topology changes caused by node mobility, makes their routing a challenging problem. tora is one of the routing protocols that successfully copes with the nodes’ mobility side effects, but it doesn’...

one of the most important extensions of the capacitated vehicle routing problem (cvrp) is the vehicle routing problem with simultaneous pickup and delivery (vrpspd) where customers require simultaneous delivery and pick-up service. in this paper, we propose an effective ant colony optimization (eaco) which includes insert, swap and 2-opt moves for solving vrpspd that is different with common an...