سال:1392 | دوره: | شماره: |تعداد مقالات:8

In this study a new approach to rank exponential fuzzy numbers using a-cuts is established. The metric distance of the interval numbers is extended to exponential fuzzy numbers. By using the ranking of exponential fuzzy numbers and using a-cuts the critical path of a project network is solved and illustrated by numerical examples.

In this paper, we introduce a new approach for solving the traveling salesman problems (TSP) and provide a solution algorithm for a variant of this problem. The concept of the proposed method is based on the Hungarian algorithm, which has been used to solve an assignment problem for reaching an optimal solution. We introduced a new fittest criterion for crossing over such problems, and illustrated it with analytical examples and by computer programming. The proposed method builds on the initial solution of the traveling salesman problem (TSP) which is very simple, easy to understand and apply.

In this paper we propose a multi-objective mathematical model to aid the marketing team of a company in customer service marketing. Customer reflects to the services provided by a company, and the reflections affect the profit of the company. Thus, the services can be evaluated by the customers to imply the company's performances. First, the services are purified based on the opinions of the customers conducting a survey study by a questionnaire. The service purification is carried out using statistical hypothesis testing. The remained services are then assessed regarding time, cost and quality objectives constructing a multi-objective mathematical model. Then, a multi-objective mathematical model is utilized to determine the services with more profits. Analytic hierarchy process (AHP) is applied to solve the multi-objective model. The applicability and validity of the proposed mechanism is illustrated in a case study.

The purpose of this paper is to investigate the levels of technical efficiency in agricultural sector of MENA countries by using Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA) approaches in 2007-2008. The results show that the total average of technical efficiency is as follows: DEABCC(0.770)>DEACCR(0.744)>SFA(0.479), and among all MENA countries, the best performance in both models is related to Qatar. Furthermore, the empirical results indicate that both the parametric and non-parametric methods provide the same rank of countries; However, in all cases SFA results are lower than those found by using DEA, which expresses high levels of random error in the data.

In this paper, a reliability approach on reconfiguration decisions in a supply chain network is studied based on coupling the simulation concepts and artificial neural network. In other words, due to the limited budget for warehouse relocation in a supply chain, the failure probability is assessed for determining the robust decision for future supply chain configuration. Traditional solving approaches can find the failure probability in problems with small scenarios and limited dimensions, while huge number of scenarios needs to be optimized by an efficient approach in terms of accuracy in obtained solution and improving the computational time simultaneously. Hence, the tuned artificial neural network (ANN) is applied to forecast the failure probability while network's parameters and available budget are stochastic. The results show that simulation of problem using ANN can work appropriately in selecting the configuration with considerable less time consumption and forecasting error.

Reverse supply chain is a process dealing with the backward flows of used/damaged products or materials. Reverse supply chain includes activities such as collection, inspection, reprocess, disposal and redistribution. A well-organized reverse supply chain can provide important advantages such as economic and environmental ones. In this study, we propose a general framework and formulate a mathematical model for product return in reverse supply chain. We consider a multilayer, multi-product for the model. The main objective of the paper is minimizing the total costs of reverse supply chain including transportation, fixed opening, operation, maintenance and remanufacturing costs of centers. To validate the mathematical model, a numerical example is solved using Lingo 9 software and the results are reported.

The survival of organizations is in the current business and occupational atmosphere depends on the introducing of new products, innovation and proposing value-inducing processes based on modern knowledge. For this, managers have to evaluate intellectual capitals as an important criterion to improve the performance of organizations. The main propose of this research is to study the relationship between intellectual capital and performance indicators of companies. In order to measure the intellectual capital, the value added intellectual capital coefficient has been used which was developed by Pulic. The sample have consists of 146 accepted companies in Tehran Stock Exchange in a seven-year period between 2004 to 2010. The statistical methods used here were correlation analysis and regression pooled least squares by SPSS 18 software. The results showed that there is a meaningful relationship between intellectual capital and Return Stock, Tobin’s Q and market to booking value (MTB). Of course the direction of this relationship and correlation to different industries is different.

The aim of this paper is to investigate the relationship between Equity Market Value (EMV) and measures of creation value of the performance evaluation (Shareholder Value Added (SVA) and Created Shareholder Value (CSV)) in Tehran Stock Exchange. Thus this paper examined the creation value in Iranian Companies by Alfred Rappaport model and to assess the relationship, liner regression tests were used and the following hypotheses were tested: 1) There is a relationship between Equity Market Value and SVA. 2) There is a relationship between Equity Market Value and CSV. The Research results indicate that, there is not significant relationship between Shareholder Value Added and EMV while there is a positive significant relationship between Created Shareholder Value and EMV. It was found that an increase in EMV is a positively -to- impact on Created Shareholder Value.