Trapezoidal fuzzy

Open Access Article

1 - A revisit of a mathematical model for solving fully fuzzy linear programming problem with trapezoidal fuzzy numbers
A. Ebrahimnejad

In this paper fully fuzzy linear programming (FFLP) problem with both equality and inequality constraints is considered where all the parameters and decision variables are represented by non-negative trapezoidal fuzzy numbers. According to the current approach, the FFLP More

In this paper fully fuzzy linear programming (FFLP) problem with both equality and inequality constraints is considered where all the parameters and decision variables are represented by non-negative trapezoidal fuzzy numbers. According to the current approach, the FFLP problem with equality constraints first is converted into a multi–objective linear programming (MOLP) problem with crisp constraints and then a lexicographic ordering method is used for solving the resulting MOLP problem. However, this approach cannot be used for finding the fuzzy optimal solution of FFLP problems with inequality constraints. The aim of this study is to point out and correct some errors in the definitions, notations operations and fuzzy ordering of the current approach for solving FFLP problems with fuzzy inequality constraints. Hence, a modified approach to obtain the fuzzy optimal solution of the FFLP problems with inequality constraints is proposed. Finally, several numerical examples are presented to illustrate the proposed approach. Manuscript profile

Open Access Article

2 - Supply chain network design with multi- mode demand based on acceptance degree of fuzzy constraints violated
Ali Mahmoodirad

This paper designs a mathematical model for supply chain network design problem including plants, distributors and customers in fuzzy environment. Each plant and distributor has several levels capacities. A multi-mode demand strategy is considered for the customers wher More

This paper designs a mathematical model for supply chain network design problem including plants, distributors and customers in fuzzy environment. Each plant and distributor has several levels capacities. A multi-mode demand strategy is considered for the customers where only one of the modes is to be selected for each customer. Considering the acceptance degree of fuzzy constraints violated, a method for solve the problem is proposed. For this aim, we proposed an order relationship for trapezoidal fuzzy numbers using their interval expectation value. According to this order relationship, the fuzzy supply chain network problem is converted to an interval supply chain network problem. Then, by combining the order relationship between intervals and acceptance degree of fuzzy constraints violated, the problem is transformed into a bi-objective program model and is solved by the global criterion method. Finally, in order to, show the effectiveness of the proposed approach, several test problems are solved in various sizes. Manuscript profile

Open Access Article

3 - Estimation of fuzzy parameters based on neural networks using trapezoidal data
razieh naderkhani Mohammad Hassan Behzadi tahereh Razzaghnia rahman farnoosh

Fuzzy regression is a generalized regression model that shows the relationship between independent and dependent variables in the fuzzy environment. Fuzzy linear regression analysis is the generalization of regression models that is appropriate using all data based on a More

Fuzzy regression is a generalized regression model that shows the relationship between independent and dependent variables in the fuzzy environment. Fuzzy linear regression analysis is the generalization of regression models that is appropriate using all data based on a specific criterion. This paper uses an adaptive neural fuzzy inference system to analyze and predict a non-parametric fuzzy regression function with non-fuzzy inputs and symmetrical trapezoidal fuzzy outputs. To this end, a new hybrid algorithm is proposed in which fuzzy minimum squares and linear programming are used to optimize secondary weights. Algorithms are applied by multi layer validation to validate models. More precisely, the accuracy of the algorithms with simulations is fully confirmed. Finally, two simulation examples were used to examine the efficiency of the model, in which the data were defined as trapezoidal numbers and by teaching them and specifying the number of rules used, the unknown parameters were estimated. Manuscript profile

Open Access Article