Nowadays, managing a supply chain is turned to be one of the fundamentals of business process.  In doing so, investigating and analyzing each and every of the processes and selecting the best of each process is an important challenge for strategic managers. In this paper Data Envelopment Analysis (DEA) technique is used and a model is provided for selecting the best suppliers with flexible inpu...

In this paper the real-world occurrence of the multiple-product multiple-constraint single period newsboy problem with two objectives, in which there is incremental discounts on the purchasing prices, is investigated. The constraints are the warehouse capacity and the batch forms of the order placements. The first objective of this problem is to find the order quantities such that the expected ...

The lateral-torsional buckling (LTB) strength of cellular steel girders that were subjected to web distortion was rarely examined. Since no formulation has been presented for predicting the capacity of such beams, in the current paper an extensive numerical investigation containing 660 specimens was modeled using finite element analysis (FEA) to consider the ultimate lateral-distortional buckli...

Location-Routing Problem (LRP) emerges as one of the hybrid optimization problems in distribution networks in which, total cost of the system would be reduced significantly by simultaneous optimization of locating a set of facilities among candidate locations and routing vehicles. In this paper, a mixed integer linear programming model is presented for a two-echelon location-routing problem wit...

in this paper, integrated direct and reverse logistics considering production, distribution, customer, devastation, retrieval centers under uncertainty are developed. in this model, cost parameters are not certain, thus the scenario-based robust optimization method is applied. the aim of this model is to minimize the total cost and obtain a robust solution. finally, a practical case study is pr...

one of the important issues in the field of organizational decisions is determine the optimal time of use the equipment. managers should take proper decision to repair, rebuild or replace the equipment, so that the greatest benefit and the least cost to the organization. in the military, moving units, items, equipment and manpower, is the part of the logistics system mission. in this regard, th...

cementation factor is a critical parameter, which affects water saturation calculation. in carbonate rocks, due to the sensitivity of this parameter to pore type, water saturation estimation has associated with high inaccuracy. hence developing a reliable mathematical strategy to determine these properties accurately is of crucial importance. to this end, genetic algorithm pattern search is emp...

In this paper, Economic Order Quantity ( ) based model for non-instantaneous deteriorating items with imperfect quality, permissible delay in payments and inflation is proposed. We adopt a time-dependent demand function. Also, the effects of time value of money are studied using the Discounted Cash Flow approach. Moreover, we assume that orders may contain a random proportion of defective items...

background: alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. the biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interaction...