Tracing NetworksTracing Networks

Yi HongDepartment of Computer ScienceUniversity of Leicester

Introduction to ontology-based database and software application

Semantic WebSemantic Web

2

“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

Tracing Networks programme

OntologyOntology

3

What is an ontology?“An ontology is a formal specification of a conceptualization” -Thomas Gruber

Domain ontology e.g. (CIDOC-CRM for archaeology, Gene, GXO for Genetics)

Ontology

Concepts

Specified byDescribes

Modelled by

Domain

Relational database vs Ontology-Relational database vs Ontology-based databasebased database

Image on a ceramic vessel found at Sopron-Várhely

4(provided by Katharina)

Example : Image tagging and search for human representation database

5

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)

Data

Relational database vs Ontology-Relational database vs Ontology-based databasebased database

6

Database schema

Entity-relationship diagram

Relational database (MS Access 2007)

Relational database vs Ontology-Relational database vs Ontology-based databasebased database

tables, fields (columns)

Data

primary-foreign key pairs

Relational vs Ontology-based Relational vs Ontology-based databasedatabase

7

Relational Database

Ontology-based Database (Triple

store) MySQL, Oracle, SQL Server,

MS Access etcJena SDB, virtuoso universal server, RDF/OWL document

Database Schema (table, field, key)

Ontology(class, property, individual)

records triples (RDF graph)

Data Structure

Basic elements

Database products

Data storage

OntologyOntology

◦Semantics Class Property Individual

8

OntologyOntologyA Triple is:

Basic element in the ontology world.contains three parts: subject, predicate and object.

OntologyOntologyA Triple is:

Basic element in the ontology world.contains three parts: subject, predicate and object.

OntologyOntologyRDF Graph A set of triples become a graph An ontology-based database is a graph

12

(Protégé Ontology Editor)

Relational database vs Ontology-Relational database vs Ontology-based databasebased database

http://protege.stanford.edu/

Relational vs Ontology-based Relational vs Ontology-based databasedatabase

13

SQL

generate

Relational Database

query

Database

Query language SPARQL

generate

query

Ontology-based Database (Triple

store)

Query Interface

Text-based keywords+ options Graph pattern

Search

Why use ontology?Why use ontology?

14

Tags: cat , mouse,

• Problem with traditional keyword search• Ambiguous semantics• Labelling objects rather than relationship

Why use ontology?Why use ontology?

15

Tags: cat , mouse,

• Problem with traditional keyword search• Ambiguous semantics• Labelling objects rather than relationship

Why use ontology?Why use ontology?

16

Tags: cat , mouse,

• Problem with traditional keyword search• Ambiguous semantics• Labelling objects rather than relationship

Why use ontology?Why use ontology?

17

Tags: cat , mouse,

• Problem with traditional keyword search• Ambiguous semantics• Labelling objects rather than relationship

chase?

Who is chasing who?

Why use ontology?Why use ontology?

18

◦ Problem with traditional keyword search Difficult to describe complex and arbitrary query Unable to perform automatic reasoning

Query:

“Display images with an animal and a person on them, along with what is happening between them"

rider

horse

Why use ontology?Why use ontology?

19

◦ Single user Mode vs Collaborative Mode Degree of uncertainty User credibility and expertise

definitely a

horse!

probably a

fox ?

Domain-specific expertise index = E(d)

Degree of uncertainty = CF

horseTagged area 95%

Is a

Query results visualisation Query results visualisation --Geo-mappingGeo-mappingKeyhole Markup Language (KML/KMZ)

http://code.google.co m/apis/kml/documentation/

◦ XML-based language.◦ Supports place marks, images, polygons, 3D

models, textual descriptionsCompatibility◦ Google Map◦ Google Maps for Mobile ◦ Google Earth◦ ESRI ArcGIS Explorer,

20

Query results visualisation Query results visualisation - Statistical charts- Statistical chartsGoogle Chart API

◦ http://code.google.com/apis/chart/◦ Interactive Flash◦ Javascript arrays or XML files

Compatibility◦ Most mainstream browsers

Internet Explorer Firefox Safari Chrome

21

22

Ontology-based software demoOntology-based software demo

Semantic tagging

Query by graph pattern

Integration with Google earth

Statistical charts

System ArchitectureSystem Architecture

23

LinksLinksA Guide to Creating Your First Ontology

◦ By Stanford University◦ http://www.ksl.stanford.edu/people/dlm/papers/ontology-

tutorial-noy-mcguinness-abstract.htmlProtégé 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.html24