Firouzabad Institute of Higher Education
Annals of Optimization Theory and Practice
2588-3666
2588-5995
1
2
2018
05
01
Linear programming problem with generalized interval-valued fuzzy numbers
1
9
EN
Rohollah
Taghaodi
Department of Mathematics, Kashan Branch, Islamic Azad University, Kashan, Iran
taghaode@yahoo.com
Fatemeh
Kardani
Department of Industrial Engineering, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman, Iran
fkardani@gmail.com
10.22121/aotp.2018.119731.1010
In this paper, we concentrate on linear programming problems in which the cost vector, the technological coefficients and the right-hand side values are interval-valued generalized trapezoidal fuzzy numbers. To the best of our knowledge, till now there is no method described in the literature to find the optimal solution of the linear programming problems with interval-valued generalized trapezoidal fuzzy numbers. We apply the signed distance for defuzzification of this problem. The crisp problem obtained after the defuzzification is solved by the linear programming methods. Finally, we give an illustrative example and its numerical solutions.
Linear programming problem,Generalized trapezoidal fuzzy number,Interval-valued generalized trapezoidal fuzzy number
http://aotp.fabad-ihe.ac.ir/article_58381.html
http://aotp.fabad-ihe.ac.ir/article_58381_a9b86c96007308f6d3316bfc2eccec6c.pdf
Firouzabad Institute of Higher Education
Annals of Optimization Theory and Practice
2588-3666
2588-5995
1
2
2018
05
01
A Fuzzy multi-product two-stage supply chain network design with possibility of direct shipment
11
22
EN
Saber
Molla-Alizadeh-Zavardehi
Department of Industrial Engineering, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman, Iran
saber.alizadeh@gmail.com
Abbas
Shoja
Department of Industrial Engineering, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman, Iran
abbas.sh61@yahoo.com
10.22121/aotp.2018.130632.1013
The configuration of the supply chain network (SCN) is one of the strategic issues that have a major impact on the overall performance of the supply chain. A well designed SCN leads to an ability to reduce the supply chain total cost. These purposes are influenced by the supply chain strategy, which is based either on direct or indirect supply or shipment. In the case of direct shipment, the products are directly transported from the point of origin to the customers. In the classic transportation problems, it is usually assumed that the transportation time and costs are certain. Most existing mathematical models neglect the presence of uncertainty within a programming environment. This uncertainty might come about because of traffic jam, machine malfunctioning, defect in raw material, interpretation of various events and etc. These emprise parameters can be considering as fuzzy numbers. In this study, for the first time a mathematical model for a responsive, multi-product two-stage, SCN with possibility of direct shipment is proposed. Because of the unpredictable factors that mentioned above, cost coefficients are considered as trapezoidal fuzzy numbers. Therefore, for validation, the proposed model is coded by GAMS software. The results showed that relevant model is valid.
Supply chain network,Direct shipment,mathematical model,Fuzzy theory
http://aotp.fabad-ihe.ac.ir/article_63490.html
http://aotp.fabad-ihe.ac.ir/article_63490_d17677e0ff2525aca943756ac3e6e384.pdf
Firouzabad Institute of Higher Education
Annals of Optimization Theory and Practice
2588-3666
2588-5995
1
2
2018
05
01
Country risk assessment by applying multi-criteria decision-making methods: a case study to rank countries in the Middle East & North Africa
23
34
EN
Ahmad
Mohammadi Dehcheshmeh
Businesses Administration, Faculty of Economic and administrative science, Istanbul Aydin University, Florya, Istanbul, Turkey
dehcheshmeh.m.a@gmail.com
Nima
Mirzaei
Department of Industrial Engineering, Faculty of Engineering, Istanbul Aydin University, Florya, Istanbul, Turkey
nimamirzaei@aydin.edu.tr
10.22121/aotp.2018.126114.1011
The Middle East and North Africa (MENA) have been attracting many international investors for decades, but the current geopolitical situation has not shown a welcoming face towards foreign investors. Consequences of war, terror and political changes in the region have forced many international companies to reconsider their plans or withdraw their investments. On the other hand, there are companies that have faith in investing in the emerging market of the MENA with fewer competitors. It must be mentioned that narrowing down the best possible decision needs research on the current situation as well as analyzing and forecasting of the upcoming situations in terms of many factors within the country concerned and the region. The Multi-Criteria Decision Making (MCDM) analysis helps investors to choose the best alternative from a set of relevant criteria. In this paper, one of the well-known MCDM methods, TOPSIS, was used to rank twenty-three countries based on twenty key indicators within the years 2000-2015. The outcome of these findings provides a set of country rankings for an interested group of decision makers, policy makers, stakeholders, and other involved parties based on their interest in the MENA region in the so-called Arab Spring and post-Arab Spring environment.
Multi-criteria decision making,TOPSIS,Country risk ranking,International investors
http://aotp.fabad-ihe.ac.ir/article_65263.html
http://aotp.fabad-ihe.ac.ir/article_65263_7b9190c5de531be2b10cebad9981f857.pdf
Firouzabad Institute of Higher Education
Annals of Optimization Theory and Practice
2588-3666
2588-5995
1
2
2018
05
01
Refueling station location problem under uncertain environment
35
45
EN
Farzaneh
Ferdowsi
Faculty of Mathematics, Shiraz University of Technology, Shiraz, Iran
f.ferdowsi@sutech.ac.ir
Milad
Nasiri
Rajaee hospital (Emtiaz), Trauma Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
traumamedicalinfo@sums.ac.ir
10.22121/aotp.2018.129441.1012
Development of the infrastructure of alternative fuel stations is one of the best ways to extend the use of alternative fuel vehicles. Hence, constructing refueling stations with minimum cost is an important issue. On the other hand, considering the exact value of cost is not match with real cases. In this regard, the cost of building station is considered as a trapezoidal fuzzy value and a mathematical fuzzy programming model is presented in this paper. In order to solve the fuzzy model, first the model is converted to an interval programming model, then the equivalent bi-objective crisp model of the interval programming problem is written. Finally, two interactive fuzzy solution approaches are used to solve the respective bi-objective crisp model. The results show that the performance of the solution approaches is the same.
Refueling station,Facility location,Fuzzy programming
http://aotp.fabad-ihe.ac.ir/article_65264.html
http://aotp.fabad-ihe.ac.ir/article_65264_51572994fe8ccfddc92ace0056fb8732.pdf