Semantic Web, Metadata, Knowledge Representation, Ontologies
Ontologies and Semantic in OpenSource projects
Transcript of Ontologies and Semantic in OpenSource projects
title
Ontologies
and Semantic
Jose Gato Luis
(4-09-2012)
2009,2011 Jose Gato Luis
Some rights reserved. This presentation is distributed under the Attribution-ShareAlike 3.0 license, by Creative Commons, available at http://creativecommons.org/licenses/by-sa/3.0/
Summary
Introduction
Ontologies
OWL and RDF.
QualiPSo: Information management
Semantic Queries
Introduction
Definition: Ontology is the philosophical study of the nature of being, existence or reality in general, as well as of the basic categories of being and their relations. Traditionally listed as a part of the major branch of philosophy known as metaphysics, ontology deals with questions concerning what entities exist or can be said to exist, and how such entities can be grouped, related within a hierarchy, and subdivided according to similarities and differences. - Wikipedia
Introduction
Computers engineering vision:
Ontology is a formal representation of a set of concepts within a domain and the relationships between those concepts. It is used to reason about the properties of that domain, and may be used to define the domain. - Wikipedia
How to make an standard, in order to define the parts of a concept.
Vocabularies to define entities and concepts.
For example, the ontology of an email or a a tree.
Knowledge representation.
Knowledge understandable by machines and computer programs.
Similar to object orientation paradigm.
Ontologies
Ontologies
This is not understandable by a machine:
CarColourPrice
Ford FiestaBlue30
Ferrari F40Red10
Information clasified and structured:
I want to rent a Ford Fiesta car by 60Class car -> Model -> Ford Fiesta
Class car -> Colour -> Blue
Class Money -> Type -> Coin
Class Money -> Value -> 60
Class Money -> Coin -> euro
Ontologies
Ontologies
blue 30 http://manufacturer/FordSpain
And relations...
Ontologies
An ontology should allow to define all the information of a concept:
Is this possible?
Standards -> Competency vs Community
Different persons will define concepts in very different ways.
Are we able to define the world around us?
Specific conceptsTree: { Root, Trunk, type... }
Difficult to define abstract conceptsComputer science with many abstract concepts
How to define the ontology of a computer? And a sotware's ontology?
Ontologies
Ontologies are useful when...
You can define enough information about a concept.
Used by many people/projects/communities
Widely spread Standard Community
Ontologies: FOAF
Friend of a Friend: http://www.foaf-project.org/
People
Activities
People relations: People living in Europe, common friends
Peter Parker Male Mr Pet
Ontologies: SIOC
Semantically-Interlinked Online Communities http://sioc-project.org/ontology
Ontologies: SIOC
Example post John there was a time
Ontologies: Mixing
To define a concept (resource), usually, you dont have enough with only one ontology
Peter Parker Male Mr Peter [email protected]
RDF
Resource Description Framework
Classes
A ressource with the property rdf:type Class
OOP and abstract charcteristics of an object, properties and behaviors
RDF class does not define behaviors. It is a data model
Resource Description Framework
Subject, predicate y objectSubject -> Resource (Jose)
Predicate -> Relation (has)
Object -> Value (car)
RDF: Triplets
"Jose" .
"car" .
.
RDF: Schemas
Schemas to define the namespaces of the resources
Property names must be associated to schemas
Nancy Ide
RDF: Schemas
RDF Schema: "http://www.w3.org/1999/02/22-rdf-syntax-ns#
DC Dublin Core: light weight RDFS vocabulary for describing generic metadata: http://purl.org/dc/elements/1.1
Nancy Ide
RDF/XML
http://xmlns.com/foaf/spec/#Person car http://es.person/jose
Foaf: friend of a friend ontology: http://http://xmlns.com/foaf/spec/
RDF/XML
car http://es.person/jose
You can use the resource type as an element name. Abbreviated RDF syntax
RDF/XML... but triplets
ILRT staff Martin Poulter
Where are the triplets?
RDF/XML... but triplets
Here they are..
RDF/XML... and graphs
RDF
Extensibility!!!!!! How do you extend the properties in your data model?
If you have a DDBB? Change tables, queries, inserts, update and modify. A nightmare.
OOP. New properties in your class, incompatibility.
RDF: add new triplets to the resources using new properties. Nothing changes.
See example of Tutorial Ivan Herman (pag 55)
RDF/XML
Parsing tool
http://www.w3.org/RDF/Validator/
OWL
Ontology Web Language
Markup language in order to publish and share information using ontologies.
Extension of RDF/XML
Classes and relations
TerminologyInstance: object
Class: collection of objects. Description concept. All classes maybe a subclass of another (base: Thing)
Properties: A property is a directed binary relation that specifies class characteristics
OWL
Terminology
Classes Descriptions: property restrictions, intersections, unions, constraints...
Axioms: subClassOf, equivalentClasshave a range which is the class Person
OWL
OWL
TerminologyProperties: A property is a directed binary relation that specifies class characteristicsDatatype properties: modelName (String datatype) is the property of Manufacturer class
Object properties: ownedBy may be an object type property of the Vehicle class and may have a range which is the class Person
OWL
Mail An electronic mail.
OWL
Online ontologies browser
http://owl.cs.manchester.ac.uk/browser/ontologies/
Examples
Pizza: http://www.co-ode.org/ontologies/pizza/2007/02/12/pizza.owl
QualiPSo
Issues in OpenSource projects
Huge amount of data in different information sources
Heterogeneous information
Information neither classified nor structured
No relations between data in different information sources
Outdated forges
QualiPSo Information management
Relations between different information sources.
Extractors searching for relations and then they put marks of meta-info using ontologies.
Relations searching for patterns: #bug 396
Some relations:Bugs -> commits -> lines of code
Bugs -> emails
Docs -> emails
Semantic Queries (SPARQL)
SPARQL:
SPARQL Protocol and RDF Query Language
Queries language
http://sparql.org/query.html
PREFIX dc: SELECT ?titleWHERE { dc:title ?title }
Examples
Commit related with bugs:
PREFIX rdf: PREFIX relation: PREFIX qvc: SELECT ?resourceWHERE { ?resource relation:commitAboutIssue ?bugID . }
Examples
Commit related with the bug #252:
PREFIX rdf: PREFIX relation: PREFIX qvc: SELECT ?resource ?messageWHERE { ?resource relation:commitAboutIssue 252 . ?resource qvc:message ?message .}
"Introduction to the Semantic Web" - Ivan Herman - http://www.w3.org/2009/Talks/0829-Nanjing-IH/
from "Introduction to the Semantic Web" - Ivan Herman - http://www.w3.org/2009/Talks/0829-Nanjing-IH/
Play with SPARQL
http://dbpedia.org/snorql/
Extract all the films
PREFIX ont:
PREFIX foaf:
PREFIX xsd: SELECT ?e WHERE { ?e rdf:type ont:Film .}
Play with SPARQL
http://dbpedia.org/snorql/
Extract all the films starred by cruise from the year 1990
PREFIX ont: PREFIX foaf: PREFIX xsd:
SELECT ?e WHERE { ?e rdf:type ont:Film . ?e ont:starring . ?e ont:releaseDate ?date. ?e ont:producer ?producer ?producer FILTER (?date >= "1990"^^xsd:date)}
Play with SPARQL
http://dbpedia.org/snorql/
Extract all the films (and producer's name) starred by cruise from the year 1990
PREFIX ont: PREFIX foaf: PREFIX xsd:
SELECT ?e ?producer ?productor_name WHERE { ?e rdf:type ont:Film . ?e ont:starring . ?e ont:releaseDate ?date. ?e ont:producer ?producer . ?producer dbpedia2:name ?productor_name FILTER (?date >= "1990-01-01"^^xsd:date)}
Play with SPARQL
http://dbpedia.org/snorql/Abstracts of movies starring Tom Cruise, released before 1999
SELECT ?subject ?label ?released ?abstract WHERE {?subject rdf:type .?subject dbpedia2:starring .?subject rdfs:comment ?abstract.?subject rdfs:label ?label.FILTER(lang(?abstract) = "en" && lang(?label) = "en").?subject ?released.FILTER(xsd:date(?released) < "2000-01-01"^^xsd:date).} ORDER BY ?releasedLIMIT 20
Jose Gato Luis
http://www.linkedin.com/in/josegatoluis
09/04/12
Jose GatoLuis
Atos, the Atos logo, Atos Consulting, Atos Worldline, Atos Sphere, Atos Cloud and Atos WorldGridare registered trademarks of Atos SA. June 2011 2011 Atos. Confidential information owned by Atos, to be used by the recipient only. This document, or any part of it, may not be reproduced, copied, circulated and/or distributed nor quoted without prior written approval from Atos.
Thank you
Atos, the Atos logo, Atos Consulting, Atos Worldline, Atos
Sphere, Atos Cloud and Atos WorldGridare registered trademarks of
Atos SA. June 2011
2011 Atos. Confidential information owned by Atos, to be used by the recipient only. This document, or any part of it, may not be reproduced, copied, circulated and/or distributed nor quoted without prior written approval from Atos.
Atos, the Atos logo, Atos Consulting, Atos Worldline, Atos Sphere, Atos Cloud and Atos WorldGridare registered trademarks of Atos SA. June 2011 2011 Atos. Confidential information owned by Atos, to be used by the recipient only. This document, or any part of it, may not be reproduced, copied, circulated and/or distributed nor quoted without prior written approval from Atos.
09/04/12
Atos, the Atos logo, Atos Consulting, Atos Worldline, Atos Sphere, Atos Cloud and Atos WorldGridare registered trademarks of Atos SA. June 2011 2011 Atos. Confidential information owned by Atos, to be used by the recipient only. This document, or any part of it, may not be reproduced, copied, circulated and/or distributed nor quoted without prior written approval from Atos.
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