The optimality conditions for linear programming problems with fuzzy coefficients are derived in this paper. Two solution concepts are proposed by considering the orderings on the set of all fuzzy numbers. The solution concepts proposed in this paper will follow from the similar solution concept, called the nondominated solution, in the multiobjective programming problem. Under these settings, ...

The paper presents FMOPSO a multiobjective optimization method that uses a Particle Swarm Optimization algorithm enhanced with a Fuzzy Logic-based controller. Our implementation makes use of a number of fuzzy rules as well as dynamic membership functions to evaluate search spaces at each iteration. The method works based on Pareto dominance and was tested using standard benchmark data sets. Our...

This paper proposes a bilevel multiobjective optimization model with fuzzy coefficients to tackle a stone resource assignment problem with the aim of decreasing dust and waste water emissions. On the upper level, the local government wants to assign a reasonable exploitation amount to each stone plant so as to minimize total emissions and maximize employment and economic profit. On the lower le...

Multiobjective combinatorial optimization problems in various disciplines remain to be the focus of extensive research due to their inherent hard nature and difficulty of finding near-optimal solutions. Iterative heuristics like Tabu Search (TS) and Simulated Evolution (SimE) have successfully been employed to solve a range of such optimization problems [1]. These heuristics are able to obtain ...

This paper presents the solution of environmental/ economic dispatch (EED) problem by using a multiobjective bees algorithm (MBA) with clustering technique. EED problem is to minimize simultaneously the total fuel cost and environmental pollution of generation while satisfying various constrains. The MBA is modified from Bees Algorithm in order to solve EED problem through compromised fuzzy and...

Portfolio selection is a usual multiobjective problem. This paper will try to deal with the optimum portfolio for a private investor, taking into account three criteria: return, risk and liquidity. These objectives, in general, are not crisp from the point of view of the investor, so we will deal with them in fuzzy terms. The problem formulation is a goal programming (G.P.) one, where the goals...

This paper proposes a new multiobjective location problem for emergency facilities, e.g. ambulance service stations and fire stations. In the problem, one of the objectives is to minimize the maximal distance of the paths from the located emergency facilities to hospitals via accidents. The other is to maximize the frequency of accidents that the emergency facilities can respond quickly. An int...

A fuzzy directed graph is used to represent the dynamic relationships among the sub-objectives of a fuzzy multiobjective optimization problem. Using the comprehensive coordination function with exponential weights, we transform a fuzzy multi-objective optimization problem into a single-objective optimization problem. The optimal solution of the single-objective optimization problem can then be ...