recently the concept of facility efficiency, which defined by data envelopment analysis (dea), introduced as a location modeling objective, that provides facilities location’s effect on their performance in serving demands. by combining the dea models with the location problem, two types of “efficiencies” are optimized: spatial efficiency which measured by finding the least cost location and al...

Cluster analysis is a useful technique in multivariate statistical analysis. Different types of hierarchical cluster analysis and K-means have been used for data analysis in previous studies. However, the K-means algorithm can be improved using some metaheuristics algorithms. In this study, we propose simulated annealing based algorithm for K-means in the clustering analysis which we refer it a...

the paper discusses the location-allocation model for logistic networks and distribution centers through considering uncertain parameters. in real-world cases, demands and transshipment costs change over the period of the time. this may lead to large cost deviation in total cost. scenario based robust optimization approaches are proposed where occurrence probability of each scenario is not know...

this comprehensive work explores the research performed inoptimization of the collection bin and in recycle bin location-allocation issues in solidwaste management. although the collection phase of solid waste management accountsfor a significant proportion of the municipal budget, it has attracted only limitedattention of the researchers. optimization of the collection bin and recycle bin loca...

Hubs are critical elements of transportation networks. Location of hubs and allocation of demands to them are of high importance in the network design. The most important purpose of these models is to minimize the cost, but path reliability is also another important factor which can influence the location of hubs. In this paper, we propose a P-center hub location model with full interconnection...

There exist various service systems that have hierarchical structure. In hierarchical service networks, facilities at different levels provide different types of services. For example, in health care systems, general centers provide low-level services such as primary health care services, while the specialized hospitals provide high-level services. Because of demand congestion in service networ...

a new guideline for proper allocation of multipoles in the multiple multipole method (mmp) is proposed. in an ‘a posteriori’ approach, subspace fitting (ssf) is used to find the best location of multipole expansions for the two dimensional dielectric scattering problem. it is shown that the best location of multipole expansions (regarding their global approximating power) coincides with the med...

in this study, a hierarchical hub location problem by considering different modes of transportation and maximum allowed delay is investigated. this study is done on iran’s express postal service with 2 days maximum delay in delivery considering ground and airport hubs. the problem is of the type of location and single allocation for collection, transfer and distribution of the shipments. all th...

Facility location-allocation models are used in a widespread variety of applications to determine the number of required facility along with the relevant allocation process. In this paper, a new mathematical model for the capacitated multi-facility location-allocation problem with probabilistic customer's locations and fuzzy customer’s demands under the Hurwicz criterion is proposed. Thi...