Kripke frames (and models) provide a suitable semantics for sub-classical logics; for example Intuitionistic Logic (of Brouwer and Heyting) axiomatizes the reflexive and transitive Kripke frames (with persistent satisfaction relations), and the Basic Logic (of Visser) axiomatizes transitive Kripke frames (with persistent satisfaction relations). Here, we investigate whether Kripke frames/models...

The problem of artificial precision demonstrates the inadequacy of näıve fuzzy semantics for vagueness. This problem is, nevertheless, satisfactorily remedied by fuzzy plurivaluationism; i.e., by taking a class of fuzzy models (a fuzzy plurivaluation), instead of a single fuzzy model, for the semantics of a vague concept. Such a fuzzy plurivaluation in turn represents the class of models of a f...

The article deals with Codd’s relational model of data and its fuzzy logic extensions. Our main purpose is to examine, from the point of view of fuzzy logic in the narrow sense, some of the extensions proposed in the literature and the relationships between them. We argue that fuzzy logic in the narrow sense is important for the fuzzy logic extensions because it provides conceptual and methodol...

This paper is a contribution to the development of model theory of fuzzy logic in narrow sense. It is known that there are many formal systems of fuzzy logic, most of them having traditional syntax and many-valued semantics. Our logic is further generalization, where also syntax is evaluated, i.e. we may consider fuzzy sets of axioms. In the paper we show the possibilities how to construct the ...

In this paper is presented the study of fuzzy logic power stabilizer for stability of a single machine infinite bus (SMIB). The performance of the system with fuzzy logic based power system stabilizer is compared with the system having conventional power system stabilizer and system without power system stabilizer. The results show that the system with fuzzy logic controller is capable of stabi...

After a basic introduction of fuzzy logic, we discuss its role in artiicial and computational intelligence. Then we present innovative applications of fuzzy logic, focusing on fuzzy expert systems, with one typical example explored in some detail. The article concludes with suggestions how artiicial intelligence and fuzzy logic can beneet from each other.

The Intuitionistic Fuzzy Sets (IFSs), proposed in 1983, are extensions of fuzzy sets. Some years after their introduction, sequentially, intuitionistic fuzzy propositional logic, intuitionistic fuzzy predicate logic, intuitionistic fuzzy modal logic and intuitionistic fuzzy temporal logic have been introduced, presented here shortly. During the last 25 years, different intuitionistic fuzzy tool...

the underground economy has long been of interest to economists and has devoted extensive studies to itself in economic literature. through fuzzy logic approach in present research, we estimated the size of underground economy of iran over the period of 1978-2010. for this purpose and according to theoretical bases and previous studies, variables such as gdp per capita, ratio of direct taxes to...