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.

In this paper we study a connection between quasicopulas and generator triples of fuzzy preference structures. We study also conditions under which fuzzy implications can be used to construct generator triples. As we show, an important property of fuzzy implications that enables us to construct a generator triple from a fuzzy implication, is the contrapositive symmetry.

The main aim of this paper is to study fuzzy congruences of typeB semigroups. After obtaining some properties and characterizations of fuzzy good congruences on adequate semigroups, we consider fuzzy good congruences on type-B semigroups. Finally, we prove a theorem giving equivalent conditions on fuzzy cancellative congruences of such semigroups. Mathematics Subject Classification: 06F05; 20M10

We study the qualitative behavior of the positive solutions of a second-order rational fuzzy difference equationwith initial conditions being positive fuzzy numbers, and parameters are positive fuzzy numbers. More precisely, we investigate existence of positive solutions, boundedness and persistence, and stability analysis of a second-order fuzzy rational difference equation. Some numerical exa...

Fuzzy number approximation by trapezoidal fuzzy numbers which preserves the expected interval is discussed. New operators that fulfill additional requirements for the core and support of the fuzzy number are suggested. These supplementary conditions guarantee the proper interpretation of the solution even for very skew original fuzzy numbers.