In this article, we use the fuzzy concept to consider the reliability of serial system and the reliability of parallel system. Since the population reliability Rj of the subsystem Pj (j = 1, 2, ..., n) is unknown, if we use the point estimate j R to estimate Rj from the statistical data in the past, we don’t know the probability of the error j R − Rj. Moreover, the reliability of the system may...

Although the equivalence between fuzzy and neural systems is considered in various aspects depending on the context, the real implication however, of this equivalence is not explicitly addressed. As result of this, unless one is expert on both the fuzzy logic and neural network fields, there is no clear indication what circumstances prevail to implement any of them. The aim of this paper is to ...

Traditional statistical methods for seismic zonation require information from many subjects, such as regional geology and neotectonics, seismicity, stress field, damage analysis of historic earthquakes, geophysics and others. These subjects are weighted differently during statistics. In fact, the information from most of these subjects is more like fuzzy sets, ie, it is a sort of estimation rat...

They appear often situations in a system's operation characterized by a degree of vagueness and/or uncertainty. In the present paper, the author uses principles of fuzzy logic to develop a general model representing such kind of situations. They also present three alternative methods for measuring a fuzzy system's effectiveness, including the use of its total possibilistic uncertainty, the clas...

Article history: Received 30 September 2010 Received in revised form 23 May 2011 Accepted 5 June 2011 Available online 8 July 2011

This paper proposes a complexity management methodology for fuzzy systems with feedback rule bases. The methodology is based on formal methods for presentation, manipulation and transformation of fuzzy rule bases. First, Boolean matrices are used for formal presentation of rule bases. Then, binary merging operations are used for formal manipulation of rule bases. Finally, repetitive merging ope...

The aim of the temperature control is to heat the system up todelimitated temperature, afterwardhold it at that temperature in insured manner. Fuzzy Logic Controller (FLC) is best way in which this type of precision control can be accomplished by controller. During past twenty yearssignificant amount of research using fuzzy logichas done in this field of control of non-linear dynamical system. ...

This paper presents a comparative evaluation of the proportional–integral, sliding mode and fuzzy logic controllers for applications to power converters. The mismatch between the characteristics which lead to varying performance is outlined. This paper also demonstrates certain similarities of both the fuzzy logic controller and sliding mode controller. Sensitivity of these controllers to suppl...

A new approach for fuzzy control of control and maintenance systems is introduced. A standard fuzzy controller with additional and new predicates is used. These predicates handle temporal aspects to detect or predict the behaviour of a process in the past or in the future. With the ability to examine the past or future behaviour, a user of the temporal fuzzy logic controller can more easily int...

This paper analyses coupled control of a nonlinear, time-varying plant. Uncoupled and coupled direct adaptive controllers, based on fuzzy logics, are synthesized to control the water level and the air pressure in a closed tank. The satisfactory efficiency of the controllers is experimentally demonstrated running the plant under the different working conditions. Coupled fuzzy controllers are com...