Inference on the Semantic Web

Inferenceon the Semantic Web
Myungjin Lee

Artificial Intelligence

Fussy
System
the intelligence of machines
methodology
Machine
Learning
Neural
Network
goal
methodology
hasApproach
Artificial
Intelligence
Genetic
Algorithm
methodology
Knowledge
Base
Approach
Logic
hasApproach
basedon
Approaches of AI

What is Semantic Web?
Web
target
Semantic
Web
Artificial
Intelligence
goal
the intelligence of machines
purpose
a vision of information
that is understandable by computers,
so that they can perform
more of the tedious work involved
in finding, sharing, and combining information
on the web.
dc:description

approach
Approach of Semantic Web
Semantic
Web
Knowledge
Base
Approach
Logic
Sentence
basedon
basedon
use
representation
representation
Ontology
representation
Propositional
Logic
Predicate
Logic
Fist Order
Logic
Description
Logic
partOf
partOf

Ontology on the Semantic Web
OWL
Ontology
component
SCOT
component
RDF
RDFS
vocabulary
component
SKOS
dc:description
XML
component
vocabulary
SIOC
URI
An ontology is a formal
explicit specification of
a conceptualization.
FOAF

Merits of Ontology
Database
Ontology
owl:sameAs
¬
owl:differentFrom
image
image
differences
differences
rdf:Bag
rdf:li
rdf:li
rdf:li
a power
of
represen-tation
Inference
Semantics

Task of Inference
Inference
being able to derive new data
from data that you already know
dc:description
task
task
dc:description
Rule
Inference
TBox
Inference
Ontology
Inference
statements
that describe a system
in terms of controlled
vocabularies
task
dc:description
task
dc:description
ABox
Inference
TBox-compliant statements
about that vocabulary
to produce valid statements
within system
based on rule

Ontology Inference
Ontology
Inference
to derive additional facts to be inferred
from instance data and class descriptions
based on own semantics
dc:description
RDF Semantics
Person
<x, y> is in IEXT(I(rdfs:subClassOf))
if and only if x and y are in IC
and ICEXT(x) is a subset of ICEXT(y)
Man
Myungjin
( Man rdfs:subClassOf Person )
( Myungjinrdf:type Man )
( Myungjinrdf:type Person )

TBox Inference
TBox
Inference
Ontology
Inference
statements
that describe a system
in terms of controlled
vocabularies
dc:description
task
<rdfs:Classrdf:about="http://xmlns.com/foaf/0.1/Document" rdfs:label="Document”>
<rdfs:subClassOfrdf:resource="http://xmlns.com/wordnet/1.6/Document"/>
</rdfs:Class>
<rdfs:Classrdf:about="http://xmlns.com/foaf/0.1/PersonalProfileDocument”>
<rdfs:subClassOfrdf:resource="http://xmlns.com/foaf/0.1/Document"/>
</rdfs:Class>
http://xmlns.com/foaf/0.1/PersonalProfileDocument
rdfs:subClassOf
http://xmlns.com/wordnet/1.6/Document

ABox Inference
Ontology
Inference
ABox
Inference
TBox-compliant statements
about that vocabulary
dc:description
task
<rdf:Propertyrdf:about="http://xmlns.com/foaf/0.1/homepage” rdfs:label="homepage“ >
<rdfs:subPropertyOfrdf:resource="http://xmlns.com/foaf/0.1/page"/>
</rdf:Property>
<foaf:Personrdf:about="#me" xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:name>Dan Brickley</foaf:name>
<foaf:homepagerdf:resource="http://danbri.org/" />
</foaf:Person>
http://xmlns.com/foaf/0.1 /#me foaf:page http://danbri.org/

Rule Inference
Rule
Inference
to produce valid statements
within system
based on rule
dc:description
if hasParent(?x, ?y)
hasParent(?x, ?z)
Man(?y)
Woman(?z)
then hasWife(?y, ?z)
hasWife
hasParent
hasParent

SWRL (Semantic Web Rule Language)
SWRL
Horn-like
Rule
Member
Submission
representation
status
editor
form
subLanguage
SWRLTab
RuleML
Body
rdf:Seq
rdf:li
rdf:li
Head
plugIn
Protégé
screenshot

Inference Engine for Semantic Web
Bossam
a forward chaining rule engine supports SWRL
dc:description
rdf:type
Pellet
an open-source Java OWL DL reasoner has SWRL-support
dc:description
Inference
Engine
rdf:type
KAON2
an infrastructure for managing OWL-DL, SWRL, and F-Logic ontologies
dc:description
rdf:type
Racer
Pro
rdf:type
processing of rules in a SWRL-based syntax by translating them into nRQL rules
dc:description
rdf:type
Jena
to derive additional RDF assertions, the axioms and rules associated with the reasoner
dc:description

SMART System
Intelligence
Information
System
Lab
Yonsei
University
java framework for semantic web application
locatedIn
created
dc:description
SMART
function
support
rdf:Bag
rdf:Bag
rdf:li
rdf:li
rdf:li
rdf:li
rdf:li
Ontology
Process
SPARQL
Process
rdf:li
SPARQL
RDF
RDFS
Rule
Inference
Ontology
Inference
SWRL
OWL

Example Demo
SWRL Rule
if sioc:Post(?x)
sioc:Post(?y)
sioc:topic(?x, ?a)
sioc:topic(?y, ?b)
rdf:type(?a, ?z)
rdf:type(?b, ?z)
then sioc:related_to(?x, ?y)
sioc:Post
sioc:Post
rdf:type
rdf:type
sioc:related_to
clouds-with-sioc
sample-post
sioc:topic
sioc:topic
semantic-web
sws.geonames.org
SPARQL Query
PREFIX sioc: <http://rdfs.org/sioc/ns#>
SELECT ?u ?v
WHERE
{
?u sioc:related_to ?v .
}
rdf:type
rdf:type
semanticweb

Issue of Inference
RDF 상에서 어디에 추론을 쓰지?
새로운 관계 발견을 통한 네트워크 분석
또 다른 RDF Vocabularies 혹은 도메인 온톨로지와의 관계 규칙 정의 및 추론
고민할 문제
추론을 위한 표현력과 복잡도
많은 룰에 의한 충돌
세상사를 반영한 규칙의 생성
철저한 준비?
표현력의 한계?

? !