This paper proposes a discrete capacitated covering location-allocation model for pharmaceutical centers. In the presented model, two objectives are considered; the first one is minimization of costs and the second one try to maximize customer satisfaction by definition of social justice. Social justice in the model means that we consider customers satisfaction by using distance. the introduced...

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 aerodynamic loads on a Canard Rotor/Wing vehicle are investigated using inviscid numerical simulations in order to understand the flight characteristics of the vehicle during conversion from rotary to fixed-wing flight. A series of numerical simulations at seven azimuthal rotor indices are presented covering a quarter turn of the rotor. With symmetry arguments, these simulations produce 25 ...

We o€er a formulation that locates hubs on a network in a competitive environment; that is, customer capture is sought, which happens whenever the location of a new hub results in a reduction of the current cost (time, distance) needed by the trac that goes from the speci®ed origin to the speci®ed destination. The formulation presented here reduces the number of variables and constraints as co...

Hubs are facilities which are used to switch and transfer commodities between terminals (supplies and demands) in many-to-many distribution systems. The p-hub center allocation problem is concerned with allocating demand and supply nodes to hubs in order to route the traffic between origindestination pairs in minimum time. The capacities of the hubs are given. Most of the researches have discus...

Article history: Received 28 June 2011 Received in revised form 5 June 2012 Accepted 3 July 2012 Available online 16 August 2012

We study the non-uniform capacitated multi-item lot-sizing (CMILS) problem. In this problem, there is a set of demands over a planning horizon of T time periods and all demands must be satisfied on time. We can place an order at the beginning of each period s, incurring an ordering cost Ks. The total quantity of all products ordered at time s can not exceed a given capacity Cs. On the other han...

in this paper smart operation of micro energy hub is presented. energy hub system consists of certain energy hubs and interconnectors that are coordinated by energy hub system operator. an energy hub contains several converters and storages to serve demanded services in most efficient manner from available energy carriers. in this paper, the flexibility of energy delivery point is enhanced u...

A recurrent task in mathematical programming requires optimizing polytopes with prohibitivelymany constraints, e.g., the primal polytope in cutting-plane methods or the dual polytope in Column Generation (CG). This paper is devoted to the ray projection technique for optimizing such polytopes: start from a feasible solution and advance on a given ray direction until intersecting a polytope face...