With the increasing rate of population in big cities around world, tendency to build new buildings suburb main or large apartments has been highlighted. In this regard, building residential complexes seen a dramatic increase these areas as it makes possible number units within reasonable space. Although have brought numerous benefits, they are some challenges regarding their construction proces...

The minimum hub cover is a new NP-hard optimization problem that has been recently introduced to the literature in the context of graph query processing. Although a standard set covering formulation has been given, alternate models have not been studied before. This paper fills in that gap and proposes several new mathematical programming models. We give two binary integer programming formulati...

an integrated model considers all parameters and elements of different deficiencies in one problem. this paper presents a new integrated model of a supply chain that simultaneously considers facility location, vehicle routing and inventory control problems as well as their interactions in one problem, called location-routing-inventory (lri) problem. this model also considers stochastic demands ...

Available online 24 December 2008

The hierarchical hub covering facility location problems are applied to distribution systems, transportation, waste disposal, treatment services, emergency services and remote communication. The problems attempt to determine the location of service providers' facilities at different levels and specify their linking directions in order to reduce costs and to establish an appropriate condition in...

In this paper, three types of (philosophical, optimistic and pessimistic) multigranulation single valued neutrosophic (SVN) covering-based rough set models are presented, and these three models are applied to the problem of multi-criteria group decision making (MCGDM).Firstly, a type of SVN covering-based rough set model is proposed.Based on this rough set model, three types of mult...

a three stage production system is considered in this paper. there are two stages to fabricate and ready the parts and an assembly stage to assembly the parts and complete the products in this system. suppose that a number of products of different kinds are ordered. each product is assembled with a set of several parts. at first the parts are produced in the first stage with parallel machines a...

multi objective quadratic fractional programming (moqfp) problem involves optimization of several objective functions in the form of a ratio of numerator and denominator functions which involve both contains linear and quadratic forms with the assumption that the set of feasible solutions is a convex polyhedral with a nite number of extreme points and the denominator part of each of the object...