Resource description framework RDF

The technological foundations of this vision currently consist of extensible Markup Language (XML) [76], XML Schema [77], the Resource Description Framework (RDF) [61], RDF Schema [62], and the Web Ontology Language [63]. These technologies are interdependent and can thus be arranged in the form of a semantic layer cake (Fig. 9). 

Introduction of XML formats was a very important step toward better intercomputer communication, but it is not a miraculous solution to all problems. Not every possible relation is easily expressed in XML (Wang et al. 2005), so specifications usually contain many implicit assumptions that are not properly formalized. The Resource Description Framework (RDF) provides a very powerful yet simple model for this formalization (Manola and Miller 2004). In this framework, any information is transformed to basic units called triplets that are combined to map the available information. This unifying mechanism can be used to express hierarchical vocabularies for domain knowledge description, as in RDF Schema (Brickley and Guha 2004) or its extension, Web Ontology Language (OWL) (Smith et al. 2004), both standardized by the W3C. 

The KAON system [871] was chosen instead. It is based on the Resource Description Framework (RDF) that also forms the base of OWL. KAON enables semantic queries directly on the backend repository (stored in a relational database) by transforming the query into SQL, at the cost of loosing some of the expressiveness of OWL. Translation of OWL ontologies, such as OntoCAPE, into the KAON system has been realized, based on their common RDFS characteristics. 

In the accuracy data accumulation system, measured data, design data and evaluation results are accumulated according to name, feature, or evaluation result of assembles. The metadata is attached in resource description framework (RDF) format [37] and has URI for identifying the accumulated data. Relationships of each assemble are stmctured in RDF format, and the user can edit the relationships. 

McBride, B. The Resource Description Framework (RDF) and its vocabulary description language RDFS. In Staab, S., Studer, R. (eds.) Handbook on Ontologies, International Handbooks on Information Systems, pp. 51-66. Springer (2004)... 

World Wide Web Consortium Resource Description Framework (RDF) (2014). http7/www.w3. org/RDF/... 

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