Fuzzy Controllers: An Integrated Approach Based on Fuzzy Logic, Rough Sets, and Evolutionary Computing

1997 ◽  
pp. 123-138 ◽  
Author(s):  
T. Y. Lin
Keyword(s):  
Fuzzy Logic ◽  
Rough Sets ◽  
Evolutionary Computing ◽  
Integrated Approach ◽  
Fuzzy Controllers

An integrated approach for aquifer vulnerability mapping using GIS and rough sets: study from an alluvial aquifer in North India

2014 ◽  
Vol 22 (7) ◽  
pp. 1561-1572 ◽  
Author(s):  
Arina Khan ◽  
Haris Hasan Khan ◽  
Rashid Umar ◽  
Muneeb Hasan Khan
Keyword(s):  
Rough Sets ◽  
Integrated Approach ◽  
Aquifer Vulnerability ◽  
Alluvial Aquifer ◽  
Vulnerability Mapping ◽  
North India

Rough Sets and Approximate Reasoning

2014 ◽  
pp. 180-228 ◽  
Author(s):  
B. K. Tripathy
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Sets ◽  
Rough Sets ◽  
Intuitionistic Fuzzy Sets ◽  
Point Of View ◽  
Approximate Reasoning ◽  
Human Reasoning ◽  
Intuitionistic Fuzzy ◽  
Application Point ◽  
Future Work

Several models have been introduced to capture impreciseness in data. Fuzzy sets introduced by Zadeh and Rough sets introduced by Pawlak are two of the most popular such models. In addition, the notion of intuitionistic fuzzy sets introduced by Atanassov and the hybrid models obtained thereof have been very fruitful from the application point of view. The introduction of fuzzy logic and the approximate reasoning obtained through it are more realistic as they are closer to human reasoning. Equality of sets in crisp mathematics is too restricted from the application point of view. Therefore, extending these concepts, three types of approximate equalities were introduced by Novotny and Pawlak using rough sets. These notions were found to be restrictive in the sense that they again boil down to equality of sets and also the lower approximate equality is artificial. Keeping these points in view, three other types of approximate equalities were introduced by Tripathy in several papers. These approximate equalities were further generalised to cover the approximate equalities of fuzzy sets and intuitionistic fuzzy sets by him. In addition, considering the generalisations of basic rough sets like the covering-based rough sets and multigranular rough sets, the study has been carried out further. In this chapter, the authors provide a comprehensive study of all these forms of approximate equalities and illustrate their applicability through several examples. In addition, they provide some problems for future work.

scholarly journals Topology in the Alternative Set Theory and Rough Sets via Fuzzy Type Theory

Mathematics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 432 ◽  
Author(s):  
Vilém Novák
Keyword(s):  
Fuzzy Logic ◽  
Set Theory ◽  
Rough Set ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Rough Sets ◽  
Type Theory ◽  
Rough Set Theory ◽  
Basic Concepts ◽  
Alternative Set

In this paper, we will visit Rough Set Theory and the Alternative Set Theory (AST) and elaborate a few selected concepts of them using the means of higher-order fuzzy logic (this is usually called Fuzzy Type Theory). We will show that the basic notions of rough set theory have already been included in AST. Using fuzzy type theory, we generalize basic concepts of rough set theory and the topological concepts of AST to become the concepts of the fuzzy set theory. We will give mostly syntactic proofs of the main properties and relations among all the considered concepts, thus showing that they are universally valid.

Research on Modeling and Control Methods of Variable-Speed Variable-Pitch Wind Turbine Generators

2011 ◽  
Vol 383-390 ◽  
pp. 2636-2643
Author(s):  
Na Li ◽  
Hai Peng Nan ◽  
Xiang Yang Yu ◽  
Li Su
Keyword(s):  
Fuzzy Logic ◽  
Peak Power Output ◽  
Pid Controllers ◽  
Variable Speed ◽  
Control Effect ◽  
Variable Pitch ◽  
Fuzzy Controllers ◽  
Modeling And Control ◽  
Power Extraction ◽  
Mechanism Model

In view of the high-order, nonlinear, strong coupling, multivariable and time varying character of wind energy conversion system, the fuzzy-logic control strategy is introduced in this paper. First, this thesis analyzes and establishes the mechanism model for each component element of the megawatt class variable-speed variable-pitch wind turbines as well as the wind speed model. Second, for the goal of maximum wind power extraction under rated wind and peak power output maintaining above rated speed wind, PID controllers as well as fuzzy-logic controllers are designed respectively by different wind velocity condition. The simulation results demonstrate that no matter for the following up performance or the anti-interference capability, the fuzzy controllers which are devised in the paper have a better control effect than PID controllers. The fuzzy controllers can reduce system’s overshoot and regulation time more effectively, offset the negative impacts of nonlinearity, and they have better robustness too.

scholarly journals A Novel Data Mining Approach for Big Data Based on Rough Sets and Fuzzy Logic

2019 ◽  
Vol 12 (6) ◽  
pp. 133-146
Author(s):  
Osama Abdelrahman ◽  
◽  
Hesham Hefny ◽  
Keyword(s):  
Data Mining ◽  
Fuzzy Logic ◽  
Big Data ◽  
Rough Sets ◽  
Data Mining Approach

Computational Intelligence Techniques Driven Intelligent Agents for Web Data Mining and Information Retrieval

2004 ◽  
pp. 15-30 ◽  
Author(s):  
Masoud Mohammadian ◽  
Ric Jentzsch
Keyword(s):  
Fuzzy Logic ◽  
Computational Intelligence ◽  
Search Engines ◽  
Intelligent Agents ◽  
Intelligent System ◽  
Information Filtering ◽  
Evolutionary Computing ◽  
Building Blocks ◽  
Improved Performance ◽  
Search And Retrieval

The World Wide Web has added an abundance of data and information to the complexity of information for disseminators and users alike. With this complexity has come the problem of finding useful and relevant information. There is a need for improved and intelligent search and retrieval engines. Current search engines are primarily passive tools. To improve the results returned by searches, intelligent agents and other technology have the potential, when used with existing search and retrieval engines, to provide a more comprehensive search with an improved performance. This research provides the building blocks for integrating intelligent agents with current search engines. It shows how an intelligent system can be constructed to assist in better information filtering, gathering and retrieval. The research is unique in the way the intelligent agents are directed and in how computational intelligence techniques (such as evolutionary computing and fuzzy logic) and intelligent agents are combined to improve information filtering and retrieval. Fuzzy logic is used to access the performance of the system and provide evolutionary computing with the necessary information to carry out its search.

Fuzzy-Based Matrix Converter Drive for Induction Motor

2017 ◽  
pp. 219-245
Author(s):  
Chitra Venugopal
Keyword(s):  
Fuzzy Logic ◽  
Induction Motor ◽  
Closed Loop ◽  
Electrical Energy ◽  
Industrial Applications ◽  
Fuzzy Controllers ◽  
Loop Control ◽  
Squirrel Cage ◽  
Save Energy ◽  
Fuzzy Logic Technique

In industrial applications, approximately, 60% of world's consumption of electrical energy passes through the windings of squirrel-cage induction motors. Hence it is necessary to select an efficient drive circuit for induction motor to save energy. The MC are preferred to replace VSC in industrial applications. To control the performance of the MC, fuzzy logic technique is proposed and simulated using Matlab/Simulink. In this chapter, the basic concepts of MCs are discussed. The implementation of fuzzy logic technique to improve the performance of MC in driving induction motor is discussed in detail. The design of fuzzy controllers and the closed loop control of induction motor is shown. It seen that the introduction of fuzzy controllers in the closed loop helped to reduce the overshoot at starting and maintain the reference speed when running with load torque. Also the input and output voltage of the MC is maintained sinusoidal.

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