The bat algorithm is a recently proposed meta-heuristic algorithm. Usually in solving the problem of optimization, the position of virtual bats is updated by flying speed, which decreases efficiency of the algorithm and accuracy of the solution. This paper has improved the location update strategy and individual selection strategy of bat algorithm, then puts forward an improved bat algorithm. T...

Abstract Customer purchasing deeds may be affected by factors such as selling price and inventory level instead of demand which is considered either constant or function of single variable which is not feasible. Consequently in the present study we have considered demand rate as a function of stock-level and selling price both. In present study, in order to develop this model it has been assume...

In this paper we consider a constrained optimization problem where the objectives are fuzzy functions (fuzzy-valued functions). Fuzzy constrained Optimization (FO) problem plays an important role in many fields, including mathematics, engineering, statistics and so on. In the other side, in the real situations, it is important to know how may obtain its numerical solution of a given interesting...

This paper discusses how to solve balanced transportation problems, with costs in the form of trapezoidal fuzzy numbers. Fuzzy are transformed into crisp using Robust’s method as a ranking function. A new approach modified Hungarian has been applied problem transportation. solves one stage optimization and yields same results other methods that two stages.

The logistic growth model with proportional harvesting is a population that takes into account factors. In real life, not all conditions can be known certainty, such as different rates in each and harvest depending on the needs of harvester. To overcome these conditions, there concept accommodates problem uncertainty, namely fuzzy concept. This induced which assumes intrinsic rate expressed by ...

The multiobjective two person matrix game problem with fuzzy payoffs is considered in this paper. It is assumed that fuzzy payoffs are triangular fuzzy numbers. The problem is converted to several multiobjective matrix game problems with interval payoffs by using the $alpha$-cuts of fuzzy payoffs. By solving these problems some $alpha$-Pareto optimal strategies with some interval outcomes are o...

This paper considers a biobjective transportation problem with various fuzzy objective functions coefficients. Fuzzy coefficients can be of different types such as triangular, trapezoidal, (semi) $L-R$, or flat (semi) $L-R$ fuzzy numbers. First, we convert the problem to a parametric interval biobjective transportation problem using $gamma$-cuts of fuzzy coefficients. Then, we consider a fix $g...

`Abstract: -A fuzzy linear state estimation model is employed, which is based on Tanaka's fuzzy linear regression model, for modeling uncertainty in power system state estimation. Both measurements uncertainty as well as parametric uncertainty is considered by fuzzy estimator. The uncertain measurements and the parameters are expressed as fuzzy numbers with a triangular membership function that...