Jean Vincent Fonou Dombeu and Magda Huisman
services and processes of the Palestinian government, thereby, enabling the interoperability of e‐Government systems.
The above review of semantic‐based e‐Government research and projects highlight key technologies including ontology, ontology languages and semantic web service; further to these, semantic web platforms for implementing ontology and web services as well as semantic data storage and query languages are needed for developing semantic web applications( Oberle et al. 2005). These semantic web technologies are discussed in the next section.
4. Discussion of semantic web technologies
4.1 What is ontology?
The most commonly used definition of ontology was proposed by Gruber( 1993). He defined ontology as an explicit specification of a conceptualization. A conceptualization is an abstract and simplified view of a domain of knowledge one wishes to represent for a certain purpose; the domain could be explicitly and formally represented using existing objects, concepts, entities and the relationships that exist between them( Gruber 1993).
With the advent of Semantic Web, ontology has attracted developers in several domains such as e‐commerce, e‐business, e‐learning, video and multimedia, e‐Government, etc.; where there is need to develop intelligent web‐based applications that can be easily integrated and interoperated to perform complex transactions / operations over the Internet. The Semantic Web languages and platforms for representing and creating ontology are discussed in the next subsection.
4.2 Semantic web ontology languages and platforms
The Semantic Web domain provides various languages for the formal representation and description of e‐ Government service workflow processes, Web services operations and documents processing using ontologies; they include Extensible Markup Language( XML), Resource Description Framework( RDF), RDF schema( RDFS), DARPA Agent Markup Language( DAML), and OWL( Laclavik 2005). Several software platforms are also used for ontology edition including WebODE, OntoEdit, KAON1, Protégé, and so forth( Calero et al. 2006). In addition to the software platforms used for the edition of ontologies, there exist APIs( Application Programming Interface) such as OWL API( Knublauch et al. 2004), Jena API( Wilkinson et al. 2003), Sesame( Watson 2008), etc., which provide facilities for the database storage and query of ontologies. The next subsection discusses the data storage and query languages for the Semantic Web.
4.3 Semantic data storage and query languages
Developing e‐Government systems using semantic technologies consists of modelling and specifying the public administration system, the services( tax return, social grants, etc.) that it delivers to the public( citizens, businesses, etc.) and the services delivery processes, using ontologies. These ontologies must be further written formally with semantic web ontologies languages such as XML, RDF, DAML, and OWL( Laclavik 2005). The resulting formal ontologies should then be stored in a traditional relational database management system( RDBMS) such as Oracle, MySQL, PostgreSQL, etc.( Wilkinson et al. 2003) and query through semantic web services in daily running of e‐Governments applications interfacing them to provide answers to citizens’ requests. The semantic web domain has developed a set of languages for the technical implementation of these semantic‐based queries. These languages include: RDQL, Semantic Web Rule Language( SWRL)( Zhang 2008), XSLT, SPARQL, etc.( Bailey et al. 2009). The next subsection discusses the dynamic part of a Semantic Web application namely semantic web services.
4.4 Semantic web services
Implementing and storing ontologies constitute the static part of the Semantic Web. Web services provide the functionalities that enable the reasoning and extraction of knowledge from the ontologies, within Semantic Web applications. Web services are software components developed to establish communication between e‐ Government systems and enable their interoperability( Bouguettaya et al. 2006). Semantic web services are web services that have been specified using Semantic Web standards such as WSMO( Web Service Modelling Ontology), SWSL( Semantic Web Services Language) and OWL‐S( OWL for services); these standards enable
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