Σημασιολογικά δίκτυα και εφαρμογές

Ψυχογιός, Άγγελος Γ.

Master Thesis

Author

Ψυχογιός, Άγγελος Γ.

Date

2013-04-11

Abstract

The World Wide Web in recent years has changed significantly the way people communicate with each other and the way they run their businesses. The Semantic Web is an extension of the previous one (World Wide Web). The Semantic Web is particularly a web of information that can be read by machines and its concept is clearly defined by standards. The aim of this thesis is to analyze the expansion and deepening in the fundamental concepts of the Semantic Web. The following sections approach in detail the concept of the Semantic Web, as well as the basic markup languages which are the following: 1. The markup language XML, a language that allows the writing of structured documents with a web user-defined vocabulary. 2. The Resource Description Framework (RDF) which is a framework for the representation of information on the World Wide Web. We analyze the basic concepts used as the graphic data model based on the vocabulary URI, data types, etc. 3. The glossary definition of RDF (RDF Schema), which defines the classes and properties that can be used to describe classes, properties and other sources. To next chapter we introduce the basic terms of the ontology stemming directly from the Science of Artificial Intelligence. We analyze what is ontology, the main functions of ontologies and how they can be represented in artificial intelligence programming languages such as Prolog and Lisp. Also a report becomes to the Ontology Inference Layer. OIL is a proposal for a web based representation and inference layer for ontologies. Then, we analyze the way in which an ontology written in language OIL. As a continuation of the above appears DAML + OIL, which is a semantic language for Web sources. It is based on W3C standards such as RDF and RDF Schema, and extends these languages with even richer configuration files. Finally, special mention is made in OWL which is an ontology language for the Semantic Web, developed by the Web Ontology Working Group (Web Ontology Working Group) Community Web (W3C).