DECISIONS AND OPERATIONS RESEARCH
Year:2018 | Volume:3 | Issue:3 |Papers Count:7

This paper considers multi-period serial production systems with Periodic order quantity (POQ) policy, lead-time uncertainties and demand dependent to the price. It is assumed that actual lead-time for each stage is probabilistic with known distribution and ordering system is multi period. During the production at each stage, the items may be produced in a longer time than it was schedule, causing a delay in production at this stage and this may result in backorders of the finished product. It is assumed in this case that a fixed percentage of the shortage is backlogged and other sales are lost. The objective of this paper is to find the pricing of unit product, planned lead-time and periodicity with quantity (POQ) policy in order to maximize the total system profit.

Energy consumption considerations in production systems have recently attracted the attention of researchers. In conventional production scheduling models the importance has more often been given to time-related rather than to energy-related performance measures. In this paper we simultaneously consider energy consumption, completion time and tardiness in the presented Multi-Objective Mixed Integer Programming flow shop scheduling model. After validating the model by solving small-scale numerical examples with Weighted Sum and Epsilon-constraint method in GAMS, the large and medium-scale examples are solved via NSGA-II and SPEA-II metaheuristic-algorithms. The results proves the efficiency of the proposed algorithms.

In the real world, diffusion of some contagions at the same time on social network is very important. Due to the large number of contagions that have been diffused on a social network at the same time, in order to reduce the model parameters and also being scalable, the contagions have been grouped and clustered and also all the clusters have been set equal on some of the researches, While this assumption is not acceptable and far from the facts of the real world. To eliminate and fix this issue in this thesis, we try to elaborate the different categories of contagions and consider, analyze and study the whole story as an evolutionary game theory and will calculate its evolution dynamics of contagions and evolutionarily stable strategy stable strategy. Evolutionary dynamics and evolutionarily stable of the contagions show the impact of a contagion in the process of diffusion from the point of view of users in two consecutive interval timing and whether it is promoted or suppressed.

Since much of human reasoning is based on imprecise, vague and subjective values, most of decision-making processing, in reality, requires handling and evaluation of fuzzy numbers. Ranking fuzzy numbers is one of very important research topics in fuzzy set theory because it is a base of decision-making in applications. Although so far, many methods for ranking of fuzzy numbers have been discussed broadly, most of them contained some shortcomings, such as requirement of complicated calculations, inconstancy with human intuition and indiscrimination. In this paper, we introduce a new method by using of the affine combination on the circumcenter. This method ranks various types of fuzzy numbers which include normal, generalized trapezoidal, and triangular fuzzy numbers along with crisp numbers with the particularity that crisp numbers are to be considered particular cases of fuzzy numbers. The advantages of the new proposed are that it can be applied for most of the defuzzification and the calculation is far simple and easy than previous methods. The effectiveness of the proposed method and its advantages is demonstrated by numerical examples, comprehensive comparing different ranking method with this method and also its benefits will be illustrated by the numerical example, as well as a case study on supply chain management.

Data Envelopment Analysis (DEA) is a method based on linear programming to measure efficiency of Decision Making Units (DMU). In classic models of DEA, the whole system had been usually considered as a Decision Making Units to evaluate respective efficiency and it is also ignored the separate processes inside the system. Whereas, the internal relations of various sectors of a Decision Making Unit can have had diverse structures which cause complexity in evaluating its efficiency, because, the type of structures and the performance of these components would have different effects on efficiency of the system. Network standpoint is one of the appropriate ways for the internal relations of units’ modeling and the relation among sub-units in a DMU may be communicated in series, parallel or mixed way. In this paper, a new convert called Star Structure was introduced as a comprehensive one. The one that every structure existing between a Decision Making Units’ sub-units can easily be converted to such structure so that can accurately evaluate a Decision Making Units’ efficiency and also using star structure, we evaluated the performance of regional electronic companies in Iran.

Industrial activities on the environment, have led to many environmental problems, including earth warming, destruction of ozone layer and increase of greenhouse gases. Manufacturing companies to stay in the market and also gain competitive advantage need to pay attention to environmental issues. Customer’ s request and also some government regulations, companies lead toward green supply chain management. The power industry in the world as on of the most important and main sector of the industry, as a stimulus to all other industries, play an important role in creating environmental problems. The main purpose of this research, indentifying effective factors in managing green supply chain management and then ranking of companies active in the green supply chain management. The case study and field of research is related to Mazandaran Electric Power Industry. First by reading literature and books, internal and external articles, 21 indicators were obtained to achieve green supply chain management, In the next step, With the help of questionnaires provided to experts and whit considering limitation's, We reached the 9 final criteria. These criteria were weighted by the method of the fuzzy hierarchy process analysis and using a pair comparison questionnaire that was provided to experts and the weight of each indicator was determined. The results showed that indicators, ability to finance, increasing the height of the power transmission towers and also use of renewable solar energy, respectively, had the highest weight and the rest of the indicators were ranked next. Eventually, with using the fuzzy topsis technique, we ranked the five active energy companies in the field of green supply chain management. The rankings of these companies are relative to their level of performance in fulfilling the criteria set out in the previous step and companies were prioritized according to weightlifting indicators.

The Islamic Revolution in Iran, always seeking a real Islamic society, has been a community centered on justice, progress and spirituality. To achieve this goal, a great deal of programs and policies have been developed and implemented. The general policies of resilient economies are the continuation and completion of past policies to achieve these aspirations. The pattern of resistance in the context of sanctions and due to its problems in the last decade has been elaborated and presented, but the thinking of this model is a comprehensive vision with long-term and strategic policies that are not just about economic sanctions. The purpose of this paper is to create a conceptual framework in which the tasks of different domains are determined to realize the resistance economy. This research seeks to answer the question of how the individual program or strategic plan of organizations and institutions is designed to achieve the goal of realizing a resilient economy? In this regard, it has been attempted on the basis of the general policies of the resistance economy, the message of the Supreme Leader and the study of the statements of leadership over the past seven years as well as the articles presented in the subject literature; the nature, requirements, characteristics and framework governing this template have been clarified that can be applied Use them.