The join dependency provides the basis for obtaining lossless join decomposition in a classical relational schema. The existence of Join dependency shows that that the tables always represent the correct data after being joined. Since the classical relational databases cannot handle imprecise data, they were extended to fuzzy relational databases so that uncertain, ambiguous, imprecise and part...

Abstract This paper presents the stability and rnbustncss analysis for fiizzy control system subject to paramctcr uncertainties, and the design of gains for thc fuzzy controller. Based on Lyapunov stability theory, stnbility nnd robustness conditions will be derived. The stability conditions involves only p+l linear matrix inequalities, where p i s the numbcr of rulcs of thc fuzzy controller. A...

In autonomous navigation of mobile robots, the dynamic environment is a source of problems. Because it is not possible to model all the possible conditions, the key point in the robot control is to design a system that is adaptable to different conditions. This paper first describes a behaviour hierarchy, which decomposes behaviours of a robot, needed to achieve a goal, into simpler behaviours....

The general mathematical problem of fuzzy control is an interpolation problem: a list of fuzzy input-output data, usually provided by a list of linguistic control rules, should be realized as argument-value pairs for a suitably chosen fuzzy function. However, contrary to the usual understanding of interpolation, in the actual approaches this interpolation problem is considered as a global one: ...

We obtain some equivalent conditions of (strictly) pseudoconvex and quasiconvex fuzzy mappings. These results will be useful to present some characterizations of solutions for fuzzy mathematical programming.

Based on Takagi–Sugeno (T–S) fuzzy approach we design a fuzzy speed control system for a permanent magnet synchronous motor (PMSM). We derive sufficient conditions for the existence of a T–S fuzzy speed regulator and acceleration observer in terms of linear matrix inequalities (LMIs). We parameterize the gain matrices using the LMI conditions. We implement the proposed T–S fuzzy speed control s...

Several necessary and suucient conditions for the pseudometric generating property of non-additive set functions are given. The relation among the pseudometric generating property and autocontinuity of fuzzy measures is depicted by using the absolute continuity and exhaustivity. Moreover, any uniformly autocontinuous nite fuzzy measure is equivalent to a subadditive nite fuzzy measure. A furthe...

A nonmonotonous reasoning model to decision making under fuzzy exceptional conditions is suggested in this paper. This model provides a tool to process incomplete, uncertain or variable information by using production rules with exceptions while attempting to model human reasoning in the field of common sense. Explicit processing of exceptional conditions reduces probability of the incorrect de...

In this paper, we introduce the notion of a fuzzy ideal in subtraction algebras, and give some conditions for a fuzzy set to be a fuzzy ideal in subtraction algebras. We also pose three questions on fuzzy ideals of subtraction algebras.