Description logics are a popular, and widely used, formalism for describing domain knowledge in a structured way. To cope with the vagueness of real-world knowledge, several fuzzy description logics have already been proposed. In this contribution, we argue that, rather than modelling all vagueness in a generalized description logic, it may be more natural to encode vague attributes in concrete...

In recent years, the extraction of data from XML documents is an important issue for XML research and development. Fuzzy processing techniques have been proposed for flexible querying to Native XML Databases. We propose the fuzzy XQuery processing techniques for Native XML database systems, where the weights of attributes can be described by linguistic terms represented by fuzzy numbers. The pr...

This work describes a novel fuzzy logic system designed to meet the real world demand of providing intelligent ranking to large repositories of documents previously encoded with non-fuzzy (crisp) metadata. The fuzzy logic prototype was tested in practice to complement the GeoConnections Discovery Portal, which is a web portal for specialized search and retrieval of Canadian geographic data reso...

OWL EL is an extension of the tractable EL description logic. Despite their inference capabilities over TBoxes, DL reasoners have a high ABox reasoning complexity which may constitute a serious limitation in the Semantic Web where we rely mainly on query answering (i.e. instance checking). The subsomption algorithm used in fuzzy EL reduce instance checking into concept satisfiability. To allow ...

In recent years, the extraction of data from XML documents is an important issue for XML research and development. Due to the nature of XML data, formulating an XML query using an XML query language such as XQuery requires considerable effort. A user must be completely familiar with the syntax of the XQuery language, and must be able to express his/her needs accurately in a syntactically correc...

The function for spatial queries has been provided in some image retrieval systems for finding images satisfying given spatial relations. However, images themselves may contain ambiguity or the image processing technologies adopted may extract objects not accurately enough. Processing image queries in a flexible way is thus desired. In this paper, we thus propose a fuzzy image matching algorith...

This paper is directed towards an infrastructure for handling both uncertainty and vagueness in the Rules, Logic, and Proof layers of the Semantic Web. More concretely, we present probabilistic fuzzy description logic programs, which combine fuzzy description logics, fuzzy logic programs (with stratified nonmonotonic negation), and probabilistic uncertainty in a uniform framework for the Semant...

Fuzzy Description Logics generalize crisp ones by providing membership degree semantics for concepts and roles by fuzzy sets. Recently, answering of conjunctive queries has been investigated and implemented in optimized reasoner systems based on the rewriting approach for crisp DLs. In this paper we investigate how to employ such existing implementations for crisp query answering in DL-LiteR ov...