Fuzzy RDF: A data model to represent fuzzy metadata

Resource Description Framework (RDF) together with RDF Schema (RDFS) is important Semantic Web standards proposed from W3C. RDF is a knowledge representation language to deal with hard semantics in the description and manipulation of crisp metadata. However, information is often vague or ambiguous. Many metadata are fuzzy by nature, and the Semantic Web should be capable to represent fuzzy data. In this paper, a fuzzy RDF data model is presented including fuzzy RDF syntax and fuzzy RDF semantics. A distinctive feature of fuzzy RDF data model, which is based on fuzzy logic theory, is able to deal with special data whose values are no more crisp values, but may be a fuzzy set.

I. Introduction

RESOURCE Description Framework (RDF) [1] is the W3C recommendation language for representing metadata about Web resources. With the constructs of the RDF data model we can describe interrelationships among resources in terms of named properties and values. Properties capture either attributes of a resource or binary relationships between resources. The definition of these attributes/relationships and their semantics is accomplished through the RDF Schema (RDFS) [2]. RDF and RDFS expressed in the basic RDF model theory [3] specify descriptive semantics in a standardized, interoperable manner via an XML-based infrastructure.