“…In particular, an ontology enumerates domain concepts and relationships among the concepts (Guarino, 1995), and provides a sound semantic ground of machine-understandable description of digital content. Ontology is popular in annotating documents with metadata, improving the performance of information retrieval and reasoning, and making data interoperable between different applications (Baziz, Boughanem, Aussenac-Gilles, & Chrisment, 2005;Duo, Juan-Zi, & Bin, 2005;Fensel, 2002;Khan, McLeod, & Hovy, 2004;Schreiber, Dubbeldam, Wielemaker, & Wielinga, 2001). In addition, an ontologyenabled semantic description of behaviors and services allows for better coordination of software agents in a multiagent system (Hendler & McGuinness, 2001;Takeda, Iino, & Nishida, 1995;Takeda, Iwata, Takaai, Sawada, & Nishida, 1996).…”