Modular Development of the DBpedia Ontology with Ontology Aspects and Web Protégé

Modular Development of the
DBpedia Ontology with Ontology
Aspects and Web Protégé
Ralph Schäfermeier, Adrian Paschke,
Alexandru Todor
Corporate Semantic Web
Institute for Computer Science
Freie Universität Berlin
4th DBpedia Community Meeting
@BIS 2015 in Poznan

Ralph Schäfermeier, Adrian Paschke  Aspect-Orientation in the DBpedia ontology  DBpedia Community Meeting 2015 Poznan
• Motivation
• Aspect-Oriented Programming
• Aspect-Oriented Ontologies
• Aspects in the DBpedia ontology
Outline

• Provenance metadata
• Quality metadata
• different with different languages
• Alignment to external ontologies
• possibly contradicting
• Enhance overall development/evolution process
• but unobtrusive
Motivation

• Used for separation of cross-cutting concerns
• Decomposition of a system based on functional and non-
functional requirements
• Generally provides semantics for:
• describing a module
• re-combining modules at runtime
Aspect-Oriented Programming

Example: Authentication
void makeDeposit(Account a, ﬂoat amount) {
AuthService as = getAuthService ();
if (!as.authenticated(a.user))
as.authenticate (a.user);
a.balance +=amount;
}
void makeWithdrawal(Account a, ﬂoat amount) {
a.balance −= amount;
}

a.balance +=amount;
}
}
Actual
business logic

a.balance +=amount;
}
} Re-occuring authentication concern
→ strong inter-dependencies

Example: Authentication Aspect
Aspect Authentication () {
}
}
a.balance +=amount;
}
Separation
into self-
contained
aspect

Example: Authentication Aspect
Aspect Authentication () {
}
@before Authentication
}
@before Authentication
a.balance +=amount;
}
Separation
into self-
contained
aspect
Connection via
"Join Points"

• A pointcut is a set of join points defined by quantification
Two Principles: Quantification and Obliviousness
8m(p1, . . . , pn) 2 M :
s(m(p1, . . . , pn)) ! (m(p1, . . . , pn) ! a(p1, . . . , pn))
[Steimann 2005, Rashid 2006]
m(p1 , . . . , pn ) ∈ M: a method adhering to the signature m(p1, . . . , pn),
M: set of all methods defined in the software system
s: a query specifying a matching criterion,
a(p1, . . . , pn): the execution of the aspect with all the parameters of
each method, respectively

• A pointcut is a set of join points defined by quantification
Two Principles: Quantification and Obliviousness
8m(p1, . . . , pn) 2 M :
s(m(p1, . . . , pn)) ! (m(p1, . . . , pn) ! a(p1, . . . , pn))
[Steimann 2005, Rashid 2006]
• Example: 
void makeDeposit(Account a, float amount) {…} 
void makeWithdrawal(Account a, float amount) {…}
@Aspect class AuthenticationAspect () {
@Before(”execution(*.make*(Account,float))”)
void authenticate(Account a, float amount) {
AuthService as = getAuthService () ;
if (!as.authenticated(a.user ))
as.authenticate (a.user ) ;
} }
Pointcut = abstract
definition of a set of
join points

• Improvement of reasoning and query result retrieval
performance
• Scalability for ontology evolution and maintenance
• Complexity management
• Amelioration of understandability
• (Partial) reuse
• Context-awareness
• Personalization
[Parent and Spaccapietra, 2009]
Modular Ontologies: Motivation

Aspect-Oriented Ontology Development:
Overview
é ontology editor4
.
s described in Section 2.4, the connections between aspects and their targe
established by using an extensional description (by providing a complete
), or intensionally (by specifying the properties of the targets using an a
or quantification). Functionality for the first variant involves manually creat
priate annotation axioms (see Figure 2, middle).
Query based
aspect annotation
Query Manual annotation/
selected editing
context in tool
Original ontology
Ontology with
aspect annotations
Aspect-based
module selection
Aspect names
or descriptions
Ontology
module
2. Our approach to aspect-oriented ontology modularization. Axioms of the original ontolo
otated with entities from an external aspect ontology (center). Axiom selection is based on que
ed manually. Module extraction happens dynamically, as a particular part of the ontology is r
Definition Selection

Ontology of Aspects
Aspect
Graph
Advice Pointcut
hasAdvice
rdf:type
rdfs:domain
rdfs:range
hasPointcut
rdf:type
owl:equivalentClass
rdf:type
hasAdvice some Advice
hasPointcut some Pointcut
≡
rdfs:range
FAO
ntology
se.
(b) Custom extension of the
original ontology for repre-
senting a temporal aspect.
(c) Modeling of the extension as an aspect by using an
axiom annotation.
"2008-02-18T00:00:00"
hasBeginning
Interval_1ingdom
recognizedBy
Kosovo
Recognition_1
self_governing
rdf:type
DateTimeInterval
rdf:type
rdf:type
recognizingEntity validity
Aspect
BuiltIn
Aspect
Resoning
Complexity
Access
Restriction
External
Aspect
Compatibility
Provenance
Based
Trust
≡ Provenance
Trust
rdfs:range
Customer
Speciﬁc
Feature
<<annotation>>
hasAspect
<<annotation>>
…
rdfs:subPropertyOf
. . .

Aspect-Oriented Ontologies

RDF example: Provenance
@prefix : <http://www.example.org/aspect123#> .
@prefix this: <http://www.example.org/aspect123> .
...
this: {
this: a aspect:Aspect .
aspect:hasPointcut :pointcut .
aspect:hasAdvice :advice .
}
:pointcut {
dbpedia:Barack_Obama dbpedia_prop:spouse dbpedia:Michelle_Obama.
}
:advice {
:pointcut prov:generatedAtTime "2004-07-29T10:38:00Z"^^xsd:dateTime .
:pointcut prov:entity <http://de.wikipedia.org/wiki/Barack_Obama>
:pointcut prov:wasAttributedTo _:a .
_:a foaf:homepage <http://de.wikipedia.org/wiki/user:Mathias_Schindler>
}

Generating views by querying aspects with named
graphs
@prefix aspect: <http://www.corporate-semantic
web.de/ontologies/aspects#> .
prefix : <…>
select ?G ?s ?p ?o where {
{graph ?G {: a aspect:Aspect}} UNION
{graph ?H {: a aspect:Aspect
{: aspect:hasPointcut ?G} UNION {:
aspect:hasAdvice ?G}}}
graph ?G {?s ?p ?o}
}

Arbitrarily many overlapping concerns
encapsulated in aspects

:pointcut prov:generatedAtTime
"2004-07-29T10:38:00Z"^^xsd:dateTime .
:pointcut prov:entity <http://de.wikipedia.org/
wiki/Barack_Obama>
_:a foaf:homepage <http://de.wikipedia.org/wiki/
user:Mathias_Schindler>
provenance

"2004-07-29T10:38:00Z"^^xsd:dateTime .
wiki/Barack_Obama>
provenance temporal semantics

"2004-07-29T10:38:00Z"^^xsd:dateTime .
wiki/Barack_Obama>
http://trustyuri.net/
RAq2h8A83lGbT2015ua85K
temporal semanticsprovenance
digital signature

"2004-07-29T10:38:00Z"^^xsd:dateTime .
wiki/Barack_Obama>
http://trustyuri.net/
RAq2h8A83lGbT2015ua85K
schema.org
DUL
…
temporal semanticsprovenance
digital signature aligments to
external ontologies

Protégé-Plugin

Web Protégé: Aspect as Modeling Context
• List of
preconfigured
named aspects
• Selected
aspects are
added to all
axioms

• universal
• unobtrusive
• use would be optional
• easy to use for ontology modelers
• reasoning on meta-model for modules possible (e.g.
module selection based on complex time constraints).
Beneﬁts

Thanks

[d'Aquin 2012] Mathieu d’Aquin. Modularizing Ontologies. In Mari Carmen Suárez-
Figueroa, Asunción Gómez- Pérez, Enrico Motta, and Aldo Gangemi, editors, Ontology
Engineering in a Networked World, pages 213–233. Springer Berlin Heidelberg, 2012
[Priss 2008] Uta Priss. Facet-like Structures in Computer Science. Axiomathes, 18(2):243–
255, June 2008.
[Steimann 2005] Friedrich Steimann. Domain Models Are Aspect Free. In Lionel Briand and
Clay Williams, editors, Model Driven Engineering Languages and Systems, number 3713 in
Lecture Notes in Computer Science, pages 171–185. Springer Berlin Heidelberg, January
2005.
[Rashid 2006] Awais Rashid and Ana Moreira. Domain Models Are NOT Aspect Free. In
Oscar Nierstrasz, Jon Whittle, David Harel, and Gianna Reggio, editors, Model Driven
Engineering Languages and Sys- tems, number 4199 in Lecture Notes in Computer Science,
pages 155–169. Springer Berlin Heidelberg, January 2006.
[Konev 2009] Boris Konev, Carsten Lutz, Dirk Walther, and Frank Wolter. Formal Properties
of Modularisation. In Heiner Stuckenschmidt, Christine Parent, and Stefano Spaccapietra,
editors, Modular Ontologies, number 5445 in Lecture Notes in Computer Science, pages
25–66. Springer Berlin Heidelberg, January 2009.
References

Modular Development of the DBpedia Ontology with Ontology Aspects and Web Protégé

Recommended

Recommended

More Related Content

Similar to Modular Development of the DBpedia Ontology with Ontology Aspects and Web Protégé

Similar to Modular Development of the DBpedia Ontology with Ontology Aspects and Web Protégé (20)

Modular Development of the DBpedia Ontology with Ontology Aspects and Web Protégé