Ontologies and Semantic in OpenSource projects

Ontologies
and Semantic

Jose Gato Luis
<jose.gato@atosresearch.eu>
(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
04/09/12 Ontologies and Semantic 2
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.


Ontologies

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

This is not understandable by a machine:

Car Colour Price

Ford Fiesta Blue 30

Ferrari F40 Red 10


Ontologies

Information clasified and structured:
I want to rent a Ford Fiesta car by 60€
Class car -> Model -> Ford Fiesta
Class car -> Colour -> Blue
Class Money -> Type -> Coin
Class Money -> Value -> 60
Class Money -> Coin -> euro


Ontologies

Something understandable by a machine:

<rdf:RDF
xmlns:rdf="http://w.o/1999/02/22-rdf-
syntax-ns#"
xmlns:coche="http://car/spec/">

<rdf:Description
rdf:about="http://car/FordFiesta”>
<car:colour> blue </car:colour>
<car:price> 30 </car:price>
</rdf:Description>

</rdf:RDF>

Ontologies

And relations...
<rdf:RDF
xmlns:rdf="http://w.o/1999/02/22-rdf-
syntax-ns#"
xmlns:coche="http://car/spec/">
<rdf:Description
rdf:about="http://car/FordFiesta”>
<car:colour> blue </car:colour>
<car:price> 30 </car:price>
<manufacturer:id>
http://manufacturer/FordSpain
</manufacturer:id>
</rdf:Description>
</rdf:RDF>

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 concepts
Tree: { Root, Trunk, type... }
Difficult to define abstract concepts

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
<foaf:Person rdf:ID=”PeterParker”>
<foaf:name>Peter Parker</foaf:name>
<foaf:gender> Male </foaf:gender>
<foaf:title> Mr </foaf:title>
<foaf:givenname>Pet</foaf:givenname>
<foaf:knows rdf:nodeID="harry"/>
</foaf:Person>

Ontologies: SIOC
Semantically-Interlinked Online Communities
http://sioc-project.org/ontology


Ontologies: SIOC

<sioc:Post rdf:about="http://..../post/7#post">
<dc:title>Example post</dc:title>
<sioc:has_creator>
<sioc:User rdf:about="person/pepe">
<sioc:name>John</sioc:name>
</sioc:User>
</sioc:has_creator>
<sioc:content>there was a time</sioc:content>
<sioc:has_reply>
<sioc:Post rdf:about="post/3#post" />
</sioc:has_reply>
</sioc:Post>


Ontologies: Mixing
To define a concept (resource), usually, you dont
have enough with only one ontology
<foaf:Person rdf:ID=”PeterParker”>
<foaf:name>Peter Parker</foaf:name>
<foaf:gender> Male </foaf:gender>
<foaf:title> Mr </foaf:title>
<foaf:givenname> Peter </foaf:givenname>
<foaf:knows rdf:nodeID="harry"/>
<sioc:email>spiderman@gmail.com</sioc:email>
</foaf:Person>


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 object
Subject -> Resource (Jose)

RDF: Triplets

<Subject> <Predicate>
<Object>

<http://es.person/jose> <http://foaf/#name> "Jose" .

<http://es.person/jose> <http://foaf/#has> "car" .

<http://es.person/jose> <http://foaf/#friend_of>

<http://es.person/jose>.


RDF: Schemas

Schemas to define the namespaces of the
resources
Property names must be associated to schemas

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description about="http://www.cs.vassar.edu/~ide/rdf/">
<dc:creator>Nancy Ide</dc:creator>
</rdf:Description>
</rdf:RDF>


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”

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description about="http://www.cs.vassar.edu/~ide/rdf/">
<dc:creator>Nancy Ide</dc:creator>
</rdf:Description>
</rdf:RDF>


RDF/XML
Foaf: friend of a friend ontology:
http://http://xmlns.com/foaf/spec/
<rdf:RDF
xmlns:rdf="http://w.o/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/">

<rdf:Description rdf:about="http://es.person/jose">

<rdf:type>http://xmlns.com/foaf/spec/#Person</rdf:type>
<foaf:has> car </foaf:has>
<foaf:friend_of> http://es.person/jose
</foaf:friend_of>
</rdf:Description>

</rdf:RDF>

RDF/XML
You can use the resource type as an element name.
Abbreviated RDF syntax

<rdf:RDF
xmlns:rdf="http://w.o/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/">

<foaf:Person rdf:about="http://es.person/jose">
<foaf:has> car </foaf:has>
<foaf:friend_of> http://es.person/jose
</foaf:friend_of>
</foaf:Person>

</rdf:RDF>


RDF/XML... but triplets
Where are the triplets?
<foaf:Group rdf:about="http://groups/ILRT">
<foaf:name>ILRT staff</foaf:name>
<foaf:member>
<foaf:Person>
<foaf:name>Martin Poulter</foaf:name>
<foaf:workplaceHomepage
rdf:resource="http://www.ilrt.bris.ac.uk/"/>
</foaf:Person>
</foaf:member>
</foaf:Group>


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
Terminology
Instance: object
Class: collection of objects. Description concept. All
classes maybe a subclass of another (base: Thing)
Properties: A property is a directed binary relation

OWL

Terminology
Classes
Descriptions: property restrictions, intersections, unions,
constraints...
Axioms: subClassOf, equivalentClass
have a range which is the class Person


<owl:Class rdf:ID="WhiteBurgundy">
<owl:intersectionOf rdf:parseType="Collection">
<owl:Class rdf:about="#Burgundy" />
<owl:Class rdf:about="#WhiteWine" />
</owl:intersectionOf>
</owl:Class>


<owl:Class rdf:ID="WhiteWine">

<owl:Class rdf:about="#Wine" />
<owl:Restriction>
<owl:onProperty rdf:resource="#hasColor" />
<owl:hasValue rdf:resource="#White" />
</owl:Restriction>

</owl:Class>


<owl:Class rdf:ID="Fruit">
<owl:unionOf rdf:parseType="Collection">
<owl:Class rdf:about="#SweetFruit" />
<owl:Class rdf:about="#NonSweetFruit" />
</owl:unionOf>
</owl:Class>


<owl:Class rdf:ID="SweetFruit">
<rdfs:subClassOf rdf:resource="#EdibleThing" />
</owl:Class>

<owl:Class rdf:ID="NonSweetFruit">
<rdfs:subClassOf rdf:resource="#EdibleThing" />
<owl:disjointWith rdf:resource="#SweetFruit" />
</owl:Class>


OWL
<owl:Class>
<owl:Class>
<owl:oneOf rdf:parseType="Collection">
<owl:Thing rdf:about="#Tosca" />
<owl:Thing rdf:about="#Salome" />
</owl:oneOf>
</owl:Class>
<owl:Class>
<owl:oneOf rdf:parseType="Collection">
<owl:Thing rdf:about="#Turandot" />
<owl:Thing rdf:about="#Tosca" />
</owl:oneOf>
</owl:Class>
</owl:Class>

OWL

Terminology
Properties: A property is a directed binary relation
that specifies class characteristics
Datatype 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

<owl:Class
rdf:about="http://....../qualipso_maillinglist#Mail">
<rdf:type
rdf:resource="http://..../2002/07/owl#Class"/>
<rdfs:label >Mail</rdfs:label>
<rdfs:comment >An electronic
mail.</rdfs:comment>
<rdfs:subClassOf
rdf:resource="http://..../ns#Post" />
</owl:Class>


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.ow


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:
<http://purl.org/dc/elements/1.1/>
SELECT ?title
WHERE
{
<http://example.org/books> dc:title ?title
}

Examples

Commit related with bugs:

PREFIX rdf: <http://.../-rdf-syntax-ns#>
PREFIX
relation:<"http://www.q.org/ont/qr#">
PREFIX qvc:<"http://www.q.org/ont/qvc#">
SELECT ?resource
WHERE
{
?resource relation:commitAboutIssue ?bugID
.
}

Examples

Commit related with the bug #252:

PREFIX rdf: <http://.../-rdf-syntax-ns#>
PREFIX
relation:<"http://www.q.org/ont/qr#">
PREFIX qvc:<"http://www.q.org/ont/qvc#">
SELECT ?resource ?message
WHERE
{
?resource relation:commitAboutIssue “252”
.
?resource qvc:message ?message .
}

"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: <http://dbpedia.org/ontology/>

PREFIX foaf: <http://xmlns.com/foaf/0.1/>

PREFIX xsd:
<http://www.w3.org/2001/XMLSchema#>
SELECT ?e WHERE {
?e rdf:type ont:Film .
}


Play with SPARQL

Extract all the films starred by cruise from the year
1990
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT ?e WHERE {
?e ont:starring <http://dbpedia.org/resource/Tom_Cruise> .
?e ont:releaseDate ?date.
?e ont:producer ?producer
?producer
FILTER (?date >= "1990"^^xsd:date)
}

Play with SPARQL

Extract all the films (and producer's name) starred by
cruise from the year 1990
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT ?e ?producer ?productor_name WHERE {
?e ont:starring <http://dbpedia.org/resource/Tom_Cruise> .
?e ont:releaseDate ?date.
?e ont:producer ?producer .
?producer dbpedia2:name ?productor_name

FILTER (?date >= "1990-01-01"^^xsd:date)
}

Play with SPARQL

Abstracts of movies starring Tom Cruise, released
before 1999
SELECT ?subject ?label ?released ?abstract WHERE {
?subject rdf:type <http://dbpedia.org/ontology/Film>.
?subject dbpedia2:starring
<http://dbpedia.org/resource/Tom_Cruise>.
?subject rdfs:comment ?abstract.
?subject rdfs:label ?label.
FILTER(lang(?abstract) = "en" && lang(?label) = "en").
?subject <http://dbpedia.org/ontology/releaseDate> ?released.
FILTER(xsd:date(?released) < "2000-01-01"^^xsd:date).
} ORDER BY ?released
LIMIT 20

Jose Gato Luis
<jose.gato@atosresearch.eu>

http://www.linkedin.com/in/josegatoluis


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