In the paper, a fuzzy variable structure control with a harmonizing mechanism has been developed and applied to the positioning control of an electro-hydraulic servo system. The simulation experiment results show that the performance by using the controller is better than those by just only using either fuzzy controller or variable structure controller. In addition, it also demonstrates that it...

We recall the concept of a linguistic variable and the representation of its values (i.e. linguistic terms) by means of fuzzy sets. In this framework adverbs are represented by fuzzy modifiers, i.e. operators acting on these fuzzy sets. We investigate two important classes of popular fuzzy modifiers. Grounding on results from psycholinguistic research, we discuss their pro’s and contra’s for re...

Given a fuzzy variable, what is the degree of difficulty of predicting the specified value that the fuzzy variable will take? Entropy provides a measure to characterize the fuzziness. Given some constraints, there are usually multiple compatible membership functions. Which membership function shall we take? The maximum entropy principle attempts to select the membership function that maximizes ...

We show that analogously to classical probability theory the conditional expectation E ( ? ~ X ) of a fuzzy random variable Y w.r.t. a fuzzy random variable X is w.r.t. a suitable metric the best approximation o f ? by measurable functions ofX. Furthermore, several linear regression functions, i.e. best approximation of ? by linear functions o f z and examples for random LR-fuzzy numbers and Ga...

Ontology has a powerful expressive ability on knowledge. In order to share and deal with the fuzzy knowledge on the semantic web, the linguistic variable ontology is proposed as the basis of the Flu Fuzzy Diagnosis System. After that, Protégé is introduced to build the fuzzy rule base. The paper concludes that linguistic variable ontology-based fuzzy diagnosis system can achieve the function of...

In this paper the convergence criterion of fuzzy random variable is investigated. An attempt is made to study the equivalence relation of uniform integrability of fuzzy random variables. Mean convergence theorem, Lebesgue dominated convergence theorem and Mean Ergodic theorem for the case of fuzzy random variable are introduced.

In this paper, we investigate renewal theories in the T -independent random fuzzy environment based on the concept of fuzzy variable and random fuzzy variable. For special cases, we consider the case for T = min and T =Archimedean t-norm. Mathematics Subject Classification: 60A86

In reliability, quality control and risk analysis, fuzzy methodologies are more and more involved and inevitably introduced difficulties in seeking fuzzy functional relationship between factors. In this paper, we propose a scalar variable formation of fuzzy regression model based on the credibility measure theoretical foundation. It is expecting our scalar variable treatments on fuzzy regressio...

This paper reveals the analytical structure of a fuzzy twoterm (PI/PD) controller which employs N1 (≥3) number of symmetric fuzzy sets for the input variable ‘displacement’, N2 (≥3) number of symmetric fuzzy sets for the input variable ‘velocity’ and N1+N2-1 number of symmetric fuzzy sets for the output variable ‘controller output’. The analytical structures are derived via triangular membershi...

The Takagi-Sugeno (T-S) fuzzy multiple-variable integral control system with fuzzy state observer is designed for the coordinated control of multi-input-multi-output (MIMO) nonlinear boilerturbine system whose operating points vary within a wide range. Linear models are first derived from the original nonlinear model on several operating points. Next the fuzzy multi-variable integral controller...