DECISIONS AND OPERATIONS RESEARCH
Year:2019 | Volume:3 | Issue:4 |Papers Count:7

One of the problems of based models on data envelopment analysis (DEA) for ranking preference voting systems is that it allows each alternative have its own weight vector. Therefore, alternatives are evaluated with different weight vectors. In this study, we propose a model based on fuzzy logic to solve the weaknesses of the previous models. This model is based on the solving of multi-objective programming models with the help of fuzzy logic, by this way it providing a vector of common weights, and finally, we can rank the alternatives.

Quadratic programming problem is one of the important problem of classic optimization problems that the aim is to find maximum or minimum amount of a quadratic function under linear constraints. In this paper the quadratic programming problem where its parameters are all nonnegative fuzzy numbers is discussed and a new algorithm based on fuzzy operations and fuzzy arithmetic is presented where reduced the fuzzy model into three smaller and more simple crisp problem. Then, by solving these crisp models using conventional algorithms such as SQP and by combining these solutions, the optimal solution of the fuzzy problem is obtained. Finally, an example is solved to implement the proposed algorithm and showing applicability of it.

Proper selection of suppliers and effective management of relationships with them is a key factor in increasing the competitiveness of companies. In order to implement this philosophy, the supplier's choice in the supply chain is considered as an important issue and leads decision makers to use valid techniques and methods to select the supplier. Choosing the right supplier will significantly reduce the cost of purchasing the raw materials as well as the waiting time until the ordered cargo arrives; it also increases the level of competitiveness of the company. In this research, a performance evaluation model for suppliers in the agile supply chain is developed using a balanced scorecard and multi-criteria decision-making methods in the uncertainty environment of Pakshu Company. In this research, using the DEMATEL method, we first determine the causal relationships of the main perspectives and indicators. Then, using the ANP method, we calculate the sub-indices weight, and finally, using the developed VIKOR method, we will evaluate the final evaluation of the suppliers of Pakshu companies. Also, agile indicators were the criteria for action and decision. In this research, five major suppliers of Pakshoo have been evaluated. Ultimately, GOLDEAST is the best performing company and ZHENGDA has the weakest performance.

Background and Aim: The present study, with an emphasis on the fundamental and critical importance of the Green Approach in the organization's marketing strategies, is interested in a scientific and practical response to this research question, which "The effect of green marketing strategies on performance through knowledge creation parameters? ". Method: The present study is based on descriptive, analytical (correlation) and applied research in the field of green and green marketing in the single-grain company. The statistical population consisted of almost 150 people. Sampling without placement from the finite society and using the Morgan table, studied 90 of the community. Librarian studies, interviews, and the use of questionnaire designed by the researcher are three methods that the present study has used to collect the information it needs. The "Cronbach Alpha" has used for measuring the reliability of the instrument. In addition, in order to test the content's validity of this tool, it is used the opinion of elites related to the subject under study with the literature and theoretical theories. Findings and Conclusion: The results showed that each of the hypotheses is statistically significant, green marketing strategies have a positive and significant effect on the organization's performance due to knowledge creation parameters, and the effect of each of the elements of the green blend on the strategies of knowledge creation is not the same.

Healthcare supply chain management, is one of the interesting topics for researchers in recent years. In the event of natural disasters and the creation of crisis situations, healthcare supply chain plays a very important and effective role in reducing fatalities and injuries, and ultimately save the lives of victims. So matters the integration of healthcare supply chain with crisis supply chain in the event of a natural disaster. In this paper, have been investigated the studies in the field of health supply chain and crisis supply chain, completely, and after analyzing these studies, have been proposed challenging issues and research opportunities in the integration of healthcare supply chain, and crisis supply chain in the event of natural disaster for future work. These issues are including of disruptions in supply chain transportation system in crisis circumstances, appropriate inventory model of the medical centers involved in the supply chain in crisis circumstances, integration of different parts of the supply chain in crisis circumstances and expanded use of information technology in the supply chain in critical circumstances.

Data Envelopment Analysis (DEA) is a mathematical model that evaluates the relative effi ciency of Decision Making Units (DMUs). The purpose of this paper was systematic study of applying this technique in Iran Banking System. In this systematic review that was conducted in September 2017, initially by searching keywords in scientific databases attempted to search the research has been conducted a bout DEA in Iranian banks regardless of the time of publication that a total of 409 research was found. Then 349 researches were removed from the study because of the irrelevant, repetitive and inaccessibility to the full text. Then attempted to statistical analysis of 60 remaining researches via Excel 2010 software. 80 percent of the researches were published in 2009 onwards. Most research has been conducted in Tehran Province and Melli and Saderat banks. The variety of choices outputs and inputs indexes was very high. In 36. 7 percent of researches; input oriented model is used also in 36. 7 percent of researches constant returns to scale is assumed. The results showed that although the interest of Iranian researchers in this field has increased, each with a particular view has analyzed the efficiency of the banks and have achieved different results.

Newton's method, which is also known as the Newton Raphson algorithm, as one of the most efficient numerical methods in mathematics, are known as a method and approach for the root approximation of nonlinear equations. After reviewing and interpretation of this method, one of the most widely used in the statistics, i. e. estimation of the unknown parameters by maximum likelihood method is presented in this paper. To facilitate the transfer of concepts, the article includes several different numerical examples and computer programs.