110 likes | 220 Views
Comparison of data facilities. Semantic Web. See Scientific American article How to express intended meaning of data Directed graph represented as a triples (resource,predicate (property) ,object) (CS639, Teacher, "Robert A. Morris") Resource must have a URI. Teacher. CS639.
E N D
Semantic Web • See Scientific American article • How to express intended meaning of data • Directed graph represented as a triples • (resource,predicate (property) ,object) • (CS639, Teacher, "Robert A. Morris") • Resource must have a URI
Teacher CS639 Robert A. Morris
RDF <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639"> <Course:Teacher>Robert A. Morris</Course:Teacher></rdf:Description> or <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639" Course:Teacher="Robert A. Morris"/ ></rdf:Description> Latter form doesn't support more structure for Teacher Course should refer to an XSchema
RDF Room http://…/gradCourse/#639 S/2/065 Teacher Name http://…/~ram Robert A. Morris S/3/075 Office
RDF <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639"> <Course:Teacher> <rdf:Description about="http://www.cs.umb.edu/~ram"> <Course:Name>Robert A. Morris</Course:Name> <Course:Office>S/3/075</Course:Office> </rdf:Description> </Course:Teacher> </rdf:Description>
RDF <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639"> <Course:Teacher> <rdf:Description about=http://www.cs.umb.edu/~ram Course:Name="Robert A. Morris" Course:Office="S/3/075" /> </Course:Teacher> </rdf:Description>
RDF <rdf:RDF xmnls:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmnls:Course= "http://www.cs.umb.edu/schemas/Course" <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639"> <Course:Teacher> <rdf:Description about="http://www.cs.umb.edu/~ram" Course:Name="Robert A. Morris" Course:Office="S/3/075" /> </Course:Teacher> </rdf:Description> </rdf:RDF>
Types <rdf:RDF xmnls:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmnls:Course= "http://www.cs.umb.edu/schemas/Course" <rdf:Description about="http://www.cs.umb.edu/Programs/grad_Course.html#CS639"> <Course:Teacher> <rdf:Description about="http://www.cs.umb.edu/~ram" rdf:type= "http://www.cs.umb.edu/schemas/Course/Person" Course:Name="Robert A. Morris" Course:Office="S/3/075" /> </Course:Teacher> </rdf:Description> </rdf:RDF>
Processing resource descriptions • A central point about RDF is to be able to reason about and otherwise process descriptions. • I.e., want to talk about the properties of descriptions, such as • are they true? • where are they asserted? • If a certain statement is true, should some other thing also be true? • Turning a Description into the kind of thing that can itself be described is called reification
Beyond RDF: The Semantic Web;interpreting information • Thesaurus: synonyms • Ontology: in philosophy, the study of things that can be described and their relationships. In CS: concepts and their relationships • Knowledge base (facts base): sentences that are true or accepted as hypothesis