Journal of Operational Research in its Applications
Year:2014 | Volume:11 | Issue:2 (41)|Papers Count:9

Disaster relief logistic planning plays an important role in Iran, as an accident-prone country, to provide service to the damaged regions. A multi-objective planning model is discussed in this research to locate temporary inventories in damaged regions for distribution of relief goods. The considered parameters in this study such as relocation cost of goods, demand amount of damaged regions and supply amount of supply centers have been considered as fuzzy numbers. The model has two main goals; 1- minimizing the cost of start-up, relocation between supply centers, temporary inventories and damaged regions, 2- maximizing total demand ratios due to keep fairness in goods distribution. In this research a genetic algorithm and a simulated annealing algorithm have been presented to solve the model. These algorithms have been compared with the exact solution of Lingo software for small size problems. In addition, these two meta-heuristic algorithms have been investigated and compared based on their performance for large size problems. The calculation results demonstrate the importance and performance of the designed model for real problems. Ultimately, a case study has been considered for Southern Khorasan as one of the most accident-prone provinces of Iran.

Estimation of activities duration and cost is a fundamental factor for most of calculations in projects control networks. So, correct estimations will play an important role in other estimations and later calculations in project scheduling. One of the basic solutions in estimation of activities duration and cost is applying the fuzzy theory. According to uncertainty in deciding parameters as well as based on experts' mental methods and long-lasting information, the theory shall be used as an approach to affiliate methods of projects scheduling to reality. In this paper applying fuzzy theory and combination of this theory with Delphi and statistical ways, suitable and creative methods to estimate activities duration and cost will be presented in shape of a trapezoidal fuzzy number. Also in order to apply the managers' view in giving dignity to experts and elites team, the techniques for decision analysis with fuzzy trapezoidal fuzzy numbers have been used. Consequently estimations raised from presented combined methods could be applied as a suitable entry in project scheduling models with fuzzy networks.

While market conditions change over the investment period, portfolio optimization models identify an optimal portfolio and hold it during the investment horizon. Accordingly, this paper presents a strategy to divide the investment period into sub-periods and revise an existing portfolio at the beginning of each sub-period. This study develops a fuzzy multi-objective nonlinear portfolio rebalancing model to upgrade a portfolio considering investor profile, transaction costs and risk-free rate of return. Finally, the proposed method is validated for three different investor profiles by using the real data derived from Tehran Stock Exchange. The results show that the proposed strategy outperforms the market.

Each year, many people around the world are affected by a variety of natural disasters. It also costs a lot of helping time for injured people. Relief logistics is considered to be as the principal of all of relief operations and aid, and it is one of the main subsystems of logistics and supply chain management. One of the problems existed in relief logistics is unpredictable events that cause some uncertain parameters. This paper presented a bi-objective model that includes several supply centers, distribution centers and demand (vulnerable) centers. The first objective is minimizing the total cost and the second one is maximizing satisfaction of applicants (injury victims). The first step, the proposed model is determined by using robust optimization method. In the second step, the bi-objective model is solved by goal programing method. Finally a comprehensive example is solved and analyzed which can be a help to understand real problems.

The main objective of this research, performance evaluation, student' welfare foundation of the Ministry of Science, Research and Technology in 1390 is based on EFQM model. The EFQM, a tool that creates the notion of organizational performance in nine areas of the standard five enablers include leadership standards, policies and strategies, human resource management (staff), and contribute to resources, processes, and contain the results of the benchmark customer, employee and community outcomes, and key performance results. The main tool for data collection in EFQM is a standard questionnaire. This survey is done with the department staff and student welfare fund managers with a total population of 107 people. 100 questionnaires have been returned to the researcher and 70 questionnaires were analyzed. For data analysis, the SPSS statistical software have been used. Our findings suggest that criteria, policies and strategies, community resources and the goal society are in good conditions.

The core purpose of this research is calculating the technical and environmental efficiency of Iran’s basic metals Industrial manufacturing by mathematical programming methods. Industries examined in this survey according to ISIC codes are basic metal manufacturing industries, primary iron and steel, basic copper, basic aluminum productions, production of precious metals and any other productions than iron, steel, copper and aluminum, iron and steel casting and nonferrous metals casting. The SBM Slack base model approach is used to evaluate the technical efficiency. The data is obtained from the statistics of factories with 10 and more workers. In addition to above mentioned data and in order to evaluate environmental efficiency; social costs of energy separated by pollutant gaseous also pollutant and greenhouse emissions of the industry sector gathered from the balance sheet of Energy and Environment Sector are also used. The Directional distance output function approach DDOF is used to calculate environmental efficiency. Based on the results, basic copper (code 2721) and basic aluminum (code 2722) manufacturing industries are efficient both from the environmental and technical point of view. And primary iron and steel (code 2710) and precious metals and other basic metals (code 2723) manufacturing industries that are technically efficient are non-efficient environmentally.

Although Internet users are facing a good opportunity having access to a large amount of information, in the lack of efficient management on available mass of data, the extent of the information would be an obstacle to progress. So today, given the large and growing amount of information requires systems that allow users to redirect their interests to be felt more than ever. Recommended systems are intelligent systems that by recognition of user interests and priority in the Internet space refine the available information and present related suitable purposes to users. These systems are considered as a tool for helping users in gaining the benefits of web space. By using recommended systems, it is possible to search about concepts that in a normal search environment cannot be accessed. In this research, by comprehensive reviewing on all personalized processes and different policies, it is tried to discuss each of methods and their efficiencies; moreover, a special manner in increasing of efficiency in this systems are considered.