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Tracing Networks. Yi Hong Department of Computer Science University of Leicester. Semantic Tagging, Search and Visualisation. Tracing Networks programme. Semantic Web. “Semantic web is an evolution to the current web and provide new information representation feature.”. Current web
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Tracing Networks Yi Hong Department of Computer Science University of Leicester Semantic Tagging, Search and Visualisation
Tracing Networks programme Semantic Web “Semantic web is an evolution to the current web and provide new information representation feature.” • Current web • Document-centric • Human readers • Syntax (Schema) • HTML, XML etc. • Semantic web • Knowledge representation • Machine readable • Semantics (Ontology) • RDF, OWL etc
Ontology • What is an ontology? • “An ontology is a formal specification of a conceptualization” • -Thomas Gruber Describes Specified by Ontology Concepts Domain Modelled by Domain ontology e.g. (CIDOC-CRM for archaeology, Gene, GXO for Genetics)
Relational database vs Ontology-based database Example : Image tagging and search for human representation database Image on a ceramic vessel found at Sopron-Várhely (provided by Katharina)
Relational database vs Ontology-based database Data • Object ID: 15 • Inventory number: 443 • Excavation site: Sopron-Várhely(N47.66519, E16.518044 Hungary) • Human figure (individuals) • rider • wagon guide • wagon rider • Animal • 2 horses • 1 horse • Material: • ceramic • Technology: • Incised ` etc. ………. (60+ attributes)
Relational database vs Ontology-based database Relational database (MS Access 2007) tables, fields (columns) primary-foreign key pairs Database schema Entity-relationship diagram Data Data
Relational vs Ontology-based database Data storage Data Structure Ontology (class, property, individual) Database Schema (table, field, key) records triples (RDF graph) Basic elements Ontology-based Database (Triple store) Relational Database Database products MySQL, Oracle, SQL Server, MS Access etc Jena SDB, virtuoso universal server, RDF/OWL document
Ontology • Semantics • Class • Property • Individual individual is instance of has value for class property restrict
Ontology • A Triple is: • Basic element in the ontology world. • contains three parts: subject, predicate and object. Predicate Subject Object
Ontology RDF Graph A set of triples become a graph An ontology-based database is a graph • A Triple is: • Basic element in the ontology world. • contains three parts: subject, predicate and object. was found in Leicester • Ceramic pot
Relational database vs Ontology-based database Ontology (Protégé Ontology Editor) Country Material ……. isLocatedIn wasMadeFrom wasFoundAt Site ……s. ……. Object Appears On Animal hasScene contains ……. subClassOf Appears On Scene Appears On Horse IndividualFigure http://protege.stanford.edu/
Relational vs Ontology-based database Search Graph pattern Text-based keywords+ options Query Interface generate generate Query language SPARQL SQL query query Ontology-based Database (Triple store) Relational Database Database
Why use ontology? • Problem with traditional keyword search • Ambiguous semantics • Labelling objects rather than relationship Tags: cat , mouse, chase?
Why use ontology? • Problem with traditional keyword search • Difficult to describe complex and arbitrary query • Unable to perform automatic reasoning rider Query: “Display images with an animal and a person on them, along with what is happening between them" horse
Why use ontology? Degree of uncertainty = CF • Single user Mode vs Collaborative Mode • Degree of uncertainty • User credibility and expertise Domain-specific expertise index = E(d) probably a fox ? definitely a horse! Is a Tagged area horse 95%
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Query results visualisation-Geo-mapping • Keyhole Markup Language (KML/KMZ) • http://code.google.co m/apis/kml/documentation/ • XML-based language. • Supports place marks, images, polygons, 3D models, textual descriptions • Compatibility • Google Map • Google Maps for Mobile • Google Earth • ESRI ArcGIS Explorer,
Query results visualisationGeo-mapping open in new window
Query results visualisation- Statistical charts • Google Chart API • http://code.google.com/apis/chart/ • Interactive Flash • Javascript arrays or XML files • Compatibility • Most mainstream browsers • Internet Explorer • Firefox • Safari • Chrome
Query results visualisation- Statistical charts open in new window
Links • A Guide to Creating Your First Ontology • By Stanford University • http://www.ksl.stanford.edu/people/dlm/papers/ontology-tutorial-noy-mcguinness-abstract.html • Protégé Ontology editor • http://protege.stanford.edu/ (Version 3.4.* ) • Protégé tutorial http://owl.cs.manchester.ac.uk/tutorials/protegeowltutorial/ • CIDOC-CRM ontology • An ontology for culture and heritage domain • http://www.cidoc-crm.org/ • KML guide and tutorial • http://code.google.com/apis/kml/documentation/kml_tut.html
Q & A Thank you! Predicate Object Subject