In this paper we consider the problem of delay-dependent robustH1 control for uncertain fuzzy systems with time-varying delay. The Takagi–Sugeno (T–S) fuzzy model is used to describe such systems. Time-delay isassumed to have lower and upper bounds. Based on the Lyapunov-Krasovskiifunctional method, a sufficient condition for the existence of a robust $H_{infty}$controller is obtained. The fuzz...

background: noise prediction is considered to be the best method for evaluating cost-preventative noise controls in industrial workrooms. one of the most important issues is the development of accurate models for analysis of the complex relationships among acoustic features affecting noise level in workrooms. in this study, advanced fuzzy approaches were employed to develop relatively accurate ...

Ever since the first hybrid fuzzy rough set model was proposed in the early 1990?s, many researchers have focused on the definition of the lower and upper approximation of a fuzzy set by means of a fuzzy relation. In this paper, we review those proposals which generalize the logical connectives and quantifiers present in the rough set approximations by means of corresponding fuzzy logic operati...

In this paper, we considered decision processes in which one decision is made in each process. We incorporate the utility function concept into the decision process, derived the utility function in fuzzy events and by the max-product operation obtained the utility possibility measure of the fuzzy events. In cases with numerous decision processes, the optimum action can be determined from the re...

In this paper, we study the concept of S-approximation spaces in fuzzy set theory and investigate its properties. Along introducing three pairs of lower and upper approximation operators for fuzzy S-approximation spaces, their properties under different assumptions, e.g. monotonicity and weak complement compatibility are studied. By employing two thresholds for minimum acceptance accuracy and m...

Attribute reduction is one of the most important problems in rough set theory. This paper introduces the concept of lower approximation reduction in ordered information systems with fuzzy decision. Moreover, the judgment theorem and discernable matrix are obtained, in which case an approach to attribute reduction in ordered information system with fuzzy decision is constructed. As an applicatio...

We present several models to obtain simple parametric representations of the fuzzy numbers or intervals, based on the use of piecewise monotonic functions of different forms. The representations have the advantage of allowing flexible and easy to control shapes of the fuzzy numbers (we use the standard -cuts setting, but also the membership functions are obtained immediately) and can be used di...

to calculate partial and total productivity of production factors in broiler farms in yazd province, 72 manufacturing units were selected based on simple random sampling method and their information and statistics were collected for one production period in the second half of 2013. to measure productivity, the cobb-douglas production function was estimated using classic and fuzzy regression met...