hossein mohebbi; adel azar; Abasali Heidari; Ameneh Khadivar
Abstract
Nowadays, most supply chains are starting to go green in their business with pay more attention to environmental protection as competitive advantage. Therefore, Designing a two-stage green supply chain for optimum assignment a green supplier to a green producer based on maximum efficiency and attention ...
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Nowadays, most supply chains are starting to go green in their business with pay more attention to environmental protection as competitive advantage. Therefore, Designing a two-stage green supply chain for optimum assignment a green supplier to a green producer based on maximum efficiency and attention to intermediate products and processes is essential. Because, economic performance and environmental performance of the supply chain will increases. One of the methods used to evaluating efficiency in the green supply chain management, is data envelopment analysis (DEA). The traditional DEA methods for evaluating efficiency of supply chain processes and multi-stage systems not working properly, Because, each decision making units is assumed as a black box and ignore its internal processes. In order to overcome this deficiency, a novel two-stage network DEA will be presented based on the concepts of Electrical Engineering that ability to consider all inputs, Intermediate products, desirable and undesirable outputs between supplier and producer in the green supply chain for optimum assignment a supplier to producer based on maximum efficiency. The proposed model has been described by an application example and Its reliability has been confirmed.
Ali Khatami Firoozabadi; Hossein Mohebbi; Mohammad Zarei Mahmoodabadi
Volume 8, Issue 21 , June 2011, , Pages 39-61
Abstract
Shortest-path problem is one of the well-known optimization problems that has been studied by many scientists in recent years. Applications of this problem such as transportation and communication are generally solved by Dijkstra's Algorithm (Labeling). In this paper, two separate scientific fields, ...
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Shortest-path problem is one of the well-known optimization problems that has been studied by many scientists in recent years. Applications of this problem such as transportation and communication are generally solved by Dijkstra's Algorithm (Labeling). In this paper, two separate scientific fields, electronics and operation research have been linked to each other and a new algorithm has been created for to find the optimization solution of a shortest- path problem by using electric networks and rules. The proposed algorithm can solve the shortest-path problem in directed graphs and no order ones, and also can solve the longest path problems in directed graphs.
In this algorithm, electrical network are used in a way that the resistance value of each branch is equal to each edge weights in the shortest-path problems. Then with using Ohm Law and Kirchhaffs Voltage Law (KVL), the current in each circuit cycle is calculated. Then the branches that contain the most passing current are specified, and according to Ohm’s Law, has the lowest resistance or weight. Thus, the shortest path in the network is achieved. Advantage of this algorithm is faster convergence to the answer and less computing time than the conventional method, especially in networks with more nods. The mentioned algorithm has been described for three examples.
