In reliability theory, the reliability measures contend the very important and depreciative role for any system analysis. Measurement of reliability measures is not easy due to ambiguity and vagueness which exist within reliability parameters. It is also very difficult to incorporate a large amount of uncertainty in well-established methodologies and techniques. However, fuzzy logic provides an...

The aim of this study is prospecting of iron and manganese in the Balvard 1:100000 sheet which is situated in Sanandaj - Sirjan structural zone utilizing Index Overlay and Fuzzy Logic methods in the GIS. In this study, the layers for integration, alterations, geological, geophysical, geochemical and structural data based on stream sediments, airborne magnetometeric and remote sensing studies. B...

Firstly, this paper presents fuzzy logic based approaches for building a tool for measuring ereadiness of a country. This paper proposes fuzzy logic for realizing the measuring tool as fuzzy logic allows processing of heterogeneous indicators and imprecise values assigned for them. The tool is constructed by using one or more fuzzy logic based inference engines. Secondly, due to the problems in...

This paper focuses on the use of advanced techniques in genetic algorithm for solving power system stabilization control problems. Dynamic stability analysis of power system is investigated considering Proportional-IntegralDerivative power system stabilizer for modern power systems. Gain settings of PID-PSS are optimized by minimizing an objective function using genetic algorithm (GA). Dynamic ...

A power system shifts to a state outside the stability boundary encountered by unstable limit cycles, at this point it will not return to the stable operating point. This resembles an increasing oscillatory behaviour in a nonlinear continuous time dynamic systems. Locating the unstable limit cycles and enhancing the stability margin is a difficult task. The effective devices for damping these o...

In this paper some algebraic structures for linguistic fuzzy models are defined for the first time. By definition linguistic fuzzy norm, stability of these systems can be considered. Two methods (normed-based & graphical-based) for stability analysis of linguist fuzzy systems will be presented. At the follow a new simple method for linguistic fuzzy numbers calculations is defined. At the end tw...

This paper proposes the application of a hierarchical fuzzy system (HFS) based on multi-input power system stabilizer (MPSS) in multi-machine environment. The number of rules increases exponentially with the number of variables in a standard fuzzy system. This problem is solved in the proposed HFS method. In this method, the total number of rules increases only linearly with the number of input...