Volume & Issue: Volume 4, Issue 1, Spring 2019 
Original Article

Modeling and solving Multi-objective Vehicle Routing Problem of Distribution Companies with Fuzzy and Stochastic Constraints (Case Study)

Pages 1-24

zeinab asadi, Mohammad Valipour khatir, abdolhamid safaei

Abstract Vehicle routing problem is one of the most important problems in transportation programming. Vehicle routing problem plays an important role in distribution companies because the much of the system costs are related to it. In this paper, a mix integer nonlinear programming model is presented considering the existing demand in distribution companies and real world's restrictions, including Stochastic service time, fuzzy demand and time window limitation. Then, the nonlinear model is equated with the linear model using analytical techniques, for its validity evaluation, GAMS software was utilized. Also, With respect to the fact that this problem is NP-Hard, non-dominated sorting genetic algorithm and multi-objective ant colony optimization algorithm are designed. To demonstrate the efficiency of designed algorithms, evaluation indicators of multi-objective meta-heuristic algorithm's efficiency are utilized. The results indicates that the non-dominated sorting genetic algorithm is more efficient. The issue of the company in questioned via the proposed algorithm. And according to company's management need, practical approach are presented.

Original Article

A Hierarchical Covering Location Model with a Multi Period under Uncertainty

Pages 25-53

Samaneh BabaeiMorad, Hassan Bagheri, Javad Behnamian Behnamian

Abstract In this study, the model in the framework of hierarchical covering location by taking a dynamic approach (the radius of coverage and the amount of demand in different periods dynamically) in the fuzzy provide and studied. Location and allocation model for hospitals and facilities that includs rescue helicopter and ambulance to the demand, to establish and cover of demand that they are in the radius of coverage, provided, and also considered the possibility of being busy facility. The status of Subspecialty hospital, hospital and clinic locate and in different periods of time are fixed. Fuzzy concept has been used to draw closer to reality. Site of the service facilities, including ambulances and helicopters are variable in different periods. Also in models for this movement is considered cost. Services machines and hospitals and clinics have limited capacity. Given the fact that the goal is just to validate the model, numerical data is used. The method of solving this problem is using the numerical example of the GAMs software definitive method, and for larger scales, the ABC algorithm and ICA are used. To validate the proposed model, it compares it with Bashiri et al. Model model. The numerical results show the optimal efficiency of the proposed solution method and the problem model.

Original Article

combination of support vector machine and pretrained convolutional neural network models to classify brain tumors in MRI images.

Pages 55-77

Alireza Balavand, Ali Hosseinzadeh kashan, abbas saghaei

Abstract Mortality in brain tumors is six times higher than other tumors due to its location. Computer systems can be used to reduce the use of inappropriate treatments and help clinicians to diagnose the disease. In this paper, a new algorithm has been used to identify tumors in 900 MRI images. This algorithm consists of four main phases, in the first phase after the input data, the preprocessing operation is performed on the images using the histogram equalization method. In the second phase, the extraction of the feature is performed using two pre-trained convolutional neural network models. The use of pre-trained convolutional neural network models makes it possible to extract higher-quality feature than traditional methods. Due to the creation of many features by convolutional neural network models, in the third phase, the probabilistic principal component analysis method is used to reduce the dimension and dependence, which ultimately extracts 100 main features of each model. In the fourth phase, using support vector machine, classification is done. In order to compare the results, three index of specificity, sensitivity, and accuracy have been used. Comparative results show that the proposed algorithm has a good performance in most data.

Original Article

Introducing a framework for analyzing the cooperation of airlines by the game theory approach

Pages 78-99

Saman Sorouri Ghare-Aghaj, Ramin Sadeghian, Reza Tavakkoli-Moghaddam, Ahmad Makui

Abstract In this research, a framework is introduced for analysis the cooperation of competing airlines. Because of increasing the number of passengers, airlines and their limited resources and also the limited passengers demand in each flight time and route, there is a competition between airlines. The airlines decide by using the game theory, about cooperation or non-cooperation with other airlines to gain more benefits. The pay-off functions of airlines are to maximise the benefits and minimize the empty seats in flights. For solving the problem, the multi-criteria game theory model will be used.
For analyzing the result of the model, three competitor airlines were selected in a Tehran-Shiraz route. The result of the model shows the strategy in an equilibrium point of each airline. The consequences of analysing the equilibrium point are the satisfied competitors or increasing profits, decreasing the empty seats, removing additional flights and reducing the air pollution caused by fuel consumption. Therefore, the strategy in the equilibrium point increases productivity in the fleet.

Original Article

Presentation of mathematical formula in Employee Value

Pages 101-118

Nafiseh Soleimani, Mohammad Aghdasi, Bakhtiar Ostadi

Abstract Employee value is a basic concept of human resource and more important in measuring. Measuring method for employee value introduced qualitatively till now. So that, consider component for employee value and achieved based on analysis. In literature there aren`t integrated component and any questionnaire for measuring, but could be compared the result based for fieldwork. Field researchers problems are that change the result by changing the sample and take time. In this paper we try to present the mathematical formula to calculate the trend of Employee value. Presented formula EVRFM composed of year of employment, last promotion year in EVR and number of promotion in EVF and percent of annual salary increased in EVM. To evaluate the formula data ware gathered from private insurance company in Tehran and calculating the employee value with EVRFM. Of the population 384 were gathered. Questioners evaluated employee value with 3components, attraction, satisfaction and loyalty. The result from EVRFM and analysis of questioners are as the same trend for evaluating the employee value. Thus EVRFM could be used for trend of employee value.

Original Article

A bi-objective mathematical model for emergency evacuation considering heterogeneous fleet of vehicles

Pages 119-137

Fatemeh Sabouhi, Ali Bozorgi-Amiri

Abstract When a region is hit by a natural or man-made disaster, planning people evacuation is one of the most challenging issues. Since relief vehicles represent a scarce resource in the disaster situations, their efficient usage plays a major role. In this paper, a simultaneous routing and scheduling of relief vehicles model are proposed to transport evacuees from affected areas to shelters. Our model has introduced two objectives. The first objective function measures the total transportation time. The second objective function represents routes reliability. We apply the augmented epsilon constraint method to determine the Pareto solutions. During the people evacuation, issues such as the feasibility of serving each affected area with multiple vehicles, heterogeneous fleet of relief vehicles and capacity constraint for shelters has been regarded. In order to represent the proposed model efficiency, we selected a random example, ran the model on it, and present solution results.

Original Article

Quantitative risk assessment of urban gas pipelines and identify sensitive areas by providing comprehensive and integrated model

Pages 140-166

mohammadtaghi ghandehari, Mansour momeni, mohammadreza mehregan

Abstract The gas pipeline is a central focus of accident-prone, so that events can be various outcomes in different aspects of human, social, financial, political or environmental is. That is why one of the most important activities for the management and risk assessment networks of natural gas pipelines, especially in towns. This is a comprehensive program of quantitative risk assessment for pipelines and gas distribution networks from sensitive areas and densely populated pass, suggests. To this end, the area of network segmentation with appropriate indicators, different possible scenarios of events in relation to gas leaks can be detected by techniques FMEA and ETA and The ultimate consequences of these scenarios and possibilities and different aspects of human, financial and social are earned, for that purpose simulator software-related incidents leakage of toxic substances have been used to obtain human consequences. Using utility theory and safety managers and experts, extracted consequences utility functions and probabilities calculated by the risk categories in relation to each scenario is obtained with the same unit. And thus different parts of the region to be ranked in terms of risk. The model presented as a case study with data collected plenty of Isfahan gas pipeline network and its events, have been described.

Original Article

Evaluation of EFQM model Projects Using the Two-Stage Model of Data Envelopment Analysis - the Game Theory Approach (Case study: 39 hospitals)

Pages 167-195

Seyedeh Raahil Mousavi, Seyed esmaiel najafi

Abstract Todays the role of performance evaluation systems to improve organization performance is undeniable each organization needs an evaluation system in order to be aware of the quality of its activities, especially in complex and dynamic environments. EFQM model is one of main models for organization self-evaluation. Health centers also use  model. Specialized model of treatment sector and EFQM model implementation experience in health sector is very effective and upgrades the quality.Using DEA along with EFQM can improve analysis process. In this research we want to offer a mixed model of EFQM and Two stage DEA to improve analysis and make it more complatible with strategic meanings. A mixed of 39 hospitals data was used to implement the model and game theory approach was used to solve this model. Implementation results shows that when results stage is selected as leader , it leads to more appropriate improvement program.

Original Article

Estimate the reliability of the supplier in the disruption using Bayesian networks and fuzzy approach

Pages 197-218

pourya naseri, mohammad Hossine karimi

Abstract Today, suppliers have a very important role for companies and organizations and Proper choice of suppliers can be considered as an important competitive advantage in the market for companies and organizations. Since suppliers have a close relationship with organizations, their final production and services depend on suppliers both in terms of quality and cost. One of the solutions in critical situations and disruptions is the use of reliable suppliers to overcome critical situations and provide raw materials. In this paper, the reliability of the supplier is estimated by examining supplier disturbances and considering the relationship between them and using the Failure Tree Analysis (FTA) technique and transforming it into the Bayesian networks. Fuzzy theory approach is used due to the precision of input information. In this paper, the validation model provided of the two suppliers of the sub-surface research institute in Isfahan has been evaluated for validation of the model.