SQL (Structured Query Language) is one of the essential topics in foundation databases courses in higher education. Due to its apparent simple syntax, learning to use the full pow...
Shazia Wasim Sadiq, Maria E. Orlowska, Wasim Sadiq...
In this paper, we present our experiences concerning the enforcement of access rights extracted from ODRL-based digital contracts. We introduce the generalized Contract Schema (Co...
Web services security specifications are typically expressed as a mixture of XML schemas, example messages, and narrative explanations. We propose a new specification language fo...
The notion of certain answers arises when one queries incompletely specified databases, e.g., in data integration and exchange scenarios, or databases with missing information. W...
Recently, there has been a wide interest in using ontologies on the Web. As a basis for this, RDF Schema (RDFS) provides means to define vocabulary, structure and constraints for ...
Stefan Decker, Dieter Fensel, Frank van Harmelen, ...