Authors:
Norihiro Ishikawa
1
;
Takeshi Kato
1
;
Hiromitsu Sumino
1
;
Johan Hjelm
2
and
Kazuhiro Miyatsu
3
Affiliations:
1
NTT DoCoMo Inc, Japan
;
2
Ericsson Research, Sweden
;
3
Ericsson Research Japan, Japan
Keyword(s):
Mobile phone, RDF, XML, Query Language, Metadata, Semantic Web
Related
Ontology
Subjects/Areas/Topics:
Artificial Intelligence
;
Collaboration and e-Services
;
e-Business
;
Enterprise Information Systems
;
Knowledge Engineering and Ontology Development
;
Knowledge-Based Systems
;
Metadata and Metamodeling
;
Searching and Browsing
;
Semantic Web
;
Soft Computing
;
Symbolic Systems
;
Web Information Systems and Technologies
;
Web Interfaces and Applications
Abstract:
Resource Description Framework (RDF) is a language which represents information about resources. In order to search RDF resource descriptions, several RDF query languages such as RQL and SquishQL have been proposed. However, these RDF query languages do not use XML syntax and they have limited functionality. xRQL is proposed to solve these issues by defining an XML-based RDF query language with enhanced manipulations of the RDF metadata. xRQL is a logic language relying on a functional approach. It consists of an operator declaration, a RDF data description and a result description. Based on RDF graph data model, xRQL defines a graphical path expression with variables, which is similar to GOQL for describing RDF data. It also adopts the object-oriented model for creation, modification and deletion operations of RDF data. Users can define their favorite XML-compliant result descriptions by themselves, which is similar to XQuery. In addition, a set of RDF operations for RDF schema is d
efined to manipulate the class and property hierarchies in RDF schema. xRQL has been implemented as an RDF query language over a native RDF database management system. This paper also briefly describes the implementation status.
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