term dependence on the semantic web

Institute of Web Science

iws.seu.edu.cn

Term Dependence on the Semantic Web

Gong Cheng and Yuzhong Qu

Institute of Web Science (IWS)

Southeast University, P.R. China

at ISWC 2008, Karlsruhe, Germany

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

What is happening on the hypertext Web

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

How about the Semantic Web

foaf:Person

foaf:Agent

wn:Agent-3

rdfs:subClassOfrdfs:subClassOf

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Term Dependence Graph (TDG)

foaf:Person

foaf:Agent

rdfs:subClassOf

wn:Agent-3

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Data Set

As of April 20089.8 million well-formed RDF documents114,408 hosts, or 7,290 registered domain names400 million RDF triples

http://iws.seu.edu.cn/services/falcons/

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Distribution of RDF documents on websites

bio2rdf.org

dbpedia.org

openlinksw.com

buzznet.com

bibsonomy.org

l3s.de

…

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Size distribution of RDF documents

Maximum at 5

NCI ThesaurusWordNet

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

How large is the TDG analyzed

1,278,233 terms as nodes (from 3,039 vocabularies)1,158,480 classes (90.6%)

118,808 properties (9.3%)

945 both (0.1%)

7,312,657 arcs (after removing self-loops)

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Distribution of terms in vocabularies

EthanAnimals

OpenCyc

DBpedia propertiesEthanAnimals

FMA

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Degree analysis of TDG

In-degree: direct influence degree

Out-degree: direct dependence degree

Average in-/out-degree: 5.72

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

In-degree

rdf:type

rdfs:subClassOf

owl:Class

rdfs:label

rdfs:comment

rdfs:Class

owl:equivalentClass

…

cyc:guid

…

64.9%

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Out-degree

40.9% at 5

Focal classes

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Correlation

Pearson’s correlation coefficient between in-degrees and out-degrees

0.006 [-1, 1]∈

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Distance analysis of TDG

foaf:Person

foaf:Agent

rdfs:subClassOf

wn:Agent-3

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Dependence depth

Average dependence depth: 10

Leaf classes in FMA

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Hop plot and effective diameter

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Connectivity analysis of TDG

93.4%

in FMA

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Connectivity analysis of TDG

over 40,000 disconnected pieces after 16 nodes are removed

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Vocabulary Dependence Graph (VDG)

foaf:Person

foaf:Agent

rdfs:subClassOf

wn:Agent-3

foaf

rdfs

wn

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

How large is the VDG analyzed

3,039 vocabularies as nodes

11,392 arcs (after removing self-loops)

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Degree analysis of VDG

rdf, rdfs, owl, daml

Average in-/out-degree: 3.75

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Distance analysis of VDG

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Connectivity analysis of VDG

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Main results

Power-laws

Complex structures within ontologieslong distance between terms

Only a few links between ontologies (excluding language-level ontologies)

All the data are available online.

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

More words

Linking Open Data (LOD)

Linking Ontologies on the Web (LOW)third-party links, e.g. ontology matching

publishing links online (collaboratively)

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Thank you for your attention

English Chinese Pronunciation

Semantic Web 语义网 yu`yiwon

Ontology 本体 benty

Class 类 ley

Property 属性 shu`shin

Institute of Web Science

iws.seu.edu.cn

Gong Cheng gcheng@seu.edu.cn

Power-law

Axy

Axy

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