-In this paper a hybrid variant of meta-heuristic algorithm ant colony optimization (ACO) is used. Approximate solutions to quadratic assignment problem have been proved very efficient. Different variants of ant colony optimization have been applied to QAP. But in this paper a hybrid approach is proposed which is combination of Ant system and Max-Min Ant system to take benefits of both the meth...

Particle swarm optimization (PSO) has received increasing interest from the optimization community due to its simplicity in implementation and its inexpensive computational overhead. However, PSO has premature convergence, especially in complex multimodal functions. Extremal Optimization (EO) is a recently developed local-search heuristic method and has been successfully applied to a wide varie...

Single-period problem (SPP) is a classical stochastic inventory model that has become very popular recently. In this research, we developed a SPP with fuzzy environment. The demand of each product is considered as LR-fuzzy variables (ranking fuzzy numbers based on the left and right deviation degrees), and multiple constraints (including service level, batch order, budget, space and upper limit...

Although most previous studies on cell formation have involved the assignment of parts and machines to cells, in recent years workers has also been considered taken into account human factor. An important step for successful implementation a Cellular Manufacturing System is decide appropriate groups parts, machines, then assign them cells. Consideration skills processing enhanced performance. I...

the travelling salesmen problem (tsp) is one of the most important and famous combinational optimization problems that aim to find the shortest tour. in this problem, the salesman starts to move from an arbitrary place called depot and after visiting all nodes, finally comes back to depot. solving this problem seems hard because program statement is simple and leads this problem belonging to np...

wireless sensor networks are the new generation of networks that typically are formed great numbers of nodes and the communications of these nodes are done as wireless. the main goal of these networks is collecting data from neighboring environment of network sensors. since the sensor nodes are battery operated and there is no possibility of charging or replacing the batteries, the lifetime of ...

the aim of a multi-mode resource-constrained project scheduling problem (mrcpsp) is to assign resource(s) with the restricted capacity to an execution mode of activities by considering relationship constraints, to achieve pre-determined objective(s). these goals vary with managers or decision makers of any organization who should determine suitable objective(s) considering organization strategi...

integrated production-distribution planning (pdp) is one of the most important approaches in supply chain networks. we consider a supply chain network (scn) to consist of multi suppliers, plants, distribution centers (dcs), and retailers. a bi-objective mixed integer linear programming model for integrating production-distribution designed here aim to simultaneously minimize total net costs in ...