Fuzzy relational database handle uncertain and imprecise information for consistent operation on database and manipulate information. In this paper, I introduced fuzzy normal forms for similarity based fuzzy relational database model. First of all I have focused on fuzzy closure of attribute set which can be utilized to find fuzzy key. Next, with the concepts of α -ffd [1], I have defined fuzzy...

In this paper we examine the possibilities to extend the relational data model with the mechanisms that can handle imprecise, uncertain and inconsistent attribute values using fuzzy logic and fuzzy sets. We present a fuzzy relational data model which we use for fuzzy knowledge representation in relational databases that guarantees the model in 3 rd normal form. We also describe the CASE tool fo...

Two fuzzy database query languages are proposed. They are used to query to fuzzy databases that are enhanced from relational databases in a way that fuzzy sets are allowed in both attribute values and truth values. A fuzzy calculus query language is constructed based on the relational calculus and a fuzzy algebra query language is also constructed based on the relational algebra. In addition, t...

This paper concerns the modeling of imprecision, vagueness, and uncertainty in databases through an extension of the relational model of data: the fuzzy rough relational database, an approach which uses both fuzzy set and rough set theories for knowledge representation of imprecise data in a relational database model. The fuzzy rough relational database is formally defined, along with a fuzzy r...

Ontology is an important part of the W3C standards for the Semantic Web used to specify standard conceptual vocabularies to exchange data among systems, provide reusable knowledge bases, and facilitate interoperability across multiple heterogeneous systems and databases. However, current ontology is not sufficient for handling vague information that is commonly found in many application domains...

in this paper, two sets of sufficient conditions are obtained to ensure the existence and stability of a unique equilibrium point of unforced first-order fuzzy relational dynamical systems by using two different approaches which are both based on the fuzzy relational matrix of the model.in the first approach, the equilibrium point of the system is one of the centers of the related membership fu...

This paper describes an extended relational database model based on probability theory and possibility theory. Fuzzy information and probabilistic information are incorporated into the relational databases simultaneously to represent fuzzy probability of events in the real-world applications. The tuples in such a relation are associated with a possibility distribution, and their attribute value...

The pioneer work of image compression/reconstruction based on fuzzy relational equations (ICF) and the related works are introduced. The ICF regards an original image as a fuzzy relation by embedding the brightness level into [0,1]. The compression/reconstruction of ICF correspond to the composition/solving inverse problem formulated on fuzzy relational equations. Optimizations of ICF can be co...

Fuzzy set theory has been extensively applied to extend various data models and resulted in numerous contributions, mainly with respect to the popular relational model or to some related form of it. To satisfy the need of modeling complex objects with imprecision and uncertainty, recently many researches have been concentrated on fuzzy semantic (conceptual) and object-oriented data models. This...