Simpósio Brasileiro de Banco de Dados 2005

A Geographic Knowledge Base A Geographic Knowledge Base for Semantic Web Applicationsfor Semantic Web ApplicationsA Geographic Knowledge Base A Geographic Knowledge Base for Semantic Web Applicationsfor Semantic Web Applications

Marcirio Silveira Chaves

Mário J. Silva

Bruno Martins

20º Brazilian Symposium on Databases - SBBD 2005

Uberlândia - MG

Linguateca

www.linguateca.pt

2005-10-03 20º Brazilian Symposium on Databases 2

Motivation/Context

• GKB - Geographic Knowledge Base– Geographic– Network

• Information exported as ontologies

• Geographic-aware Semantic Web applications

• GREASE – Geographic Reasoning for Search Engines


Presentation Structure

Conceptual Design of GKBKnowledge IntegrationUsing Geographic Knowledge in GKBGKB as an OntologyStatistics of the Ontologies CreatedApplications using GKBFinal Remarks


Information Sources used by GKB

• Geo-Administrative and Geo-Physical Domain– Administrative– Postal– Gazetteers– Wikipedia

• Network Domain

– FCCN • Web domains• Web sites


Architecture of GKB


Feature concept in GKB

• A meaningful object in the selected domain of discourse [ISO19109].Ex.:

• countries, cities and localities


Conceptual Design of GKB

• GKB meta-model





Knowledge Integration in GKB

• GKB hierarchy from different information sources• Algorithm:

– It searches the lowest common features types in both hierarchies

– If it holds, it identifies the common instances between the hierarchies

– Once the common instances are identified, it goes up the hierarchy and searches for the lowest common ancestor

– It verifies the distance (in number of relationships partOf) between the common instances of the features types and its ancestors. The ancestor, which has the small distance up to the common instances is merged through a relationship partOf with the ancestor in the another hierarchy.

The existing relationships in both hierarchies are maintained.



• GKB hierarchy from different information sources

H1

Norte

Grande Porto

Tâmega

MatosinhosVila

Nova de Gaia

Penafiel

NUT2

NUT3

MUNICIPALITYMUNICIPALITY

H2

Porto

MatosinhosVila

Nova de Gaia

Penafiel

DISTRITO




H1

Norte

Grande Porto

Tâmega

MatosinhosVila

Nova de Gaia

Penafiel

NUT2

NUT3


H2

Porto

MatosinhosVila

Nova de Gaia

Penafiel

DISTRITO




H1

Norte

Grande Porto

Tâmega

MatosinhosVila

Nova de Gaia

Penafiel

NUT2

NUT3


H2

Porto

MatosinhosVila

Nova de Gaia

Penafiel

DISTRITO



Merged Hierarchy

Norte

Grande Porto

Porto

Tâmega

PenafielMatosinhosVila

Nova de Gaia





Using Geographic Knowledge in GKB

• Geographic scopes– www.cm-lisboa.pt– Lisboa (municipality)

• Rules• New relationships and knowledge• Description Logics (DLs)• Geo domain

– Names composed of multiple words are represented in different ways

• Network domain– Names of URLs are decomposed by the correspondent domain

division

http://www.cm-lisboa.pt/


• ABox in DLs for the:– municipality of Santiago do Cacém

geoFeatureName(270,“santiagodocacem”)geoFeatureName(270,“santiagocacem”).geoFeatureName(270,“santiago-do-cacem”).geoFeatureName(270,“santiago-cacem”).geoFeatureType(270,“CON”).

– web site: www.cm-santiago-do-cacem.ptnetSiteSubDomain(33684,“www”).netSitePrefix(33684,“cm”).netSiteDomainToken(33684,“santiago-do-cacem”).netSiteTLD(33684,“pt”).



• Terminology Description (TBox in DLs)

– MunicipalitieshasScope(idN,idG)

netSiteDomainToken(idN,X) ((netSitePrefix(idN,“cm”) netSitePrefix(idN,“mun”)) geoFeatureType(idG,“CON”) geoFeatureName(idG,X).



• Ex.:hasScope(idN,idG) netSiteDomainToken(idN,X) (netSitePrefix(idN,“cm”) netSitePrefix(idN,“mun”)) geoFeatureType(idG,“CON”) geoFeatureName(idG,X).

netSiteDomainToken(33684, “santiago-do-cacem”).netSitePrefix(33684, “cm”).geoFeatureType(270, “CON”).geoFeatureName(270, “santiago-do-cacem”).

New knowledge: hasScope(33684, 270).



• Rule-based assigned scopes by GKB to sites of Portugal

Site Type # of sites # of matches

distritos 33 17 (52%)

municipalities 288 261 (90%)

freguesias 300 124 (41%)

basic schools 1955 124 (6%)

training centers 152 55 (36%)

high schools 402 105 (26%)


• Scopes extended to the web pages under each one of the sites of matching subdomains





GKB as an Ontology

<gn:Geo_Feature rdf:ID="GEO_238">

<gn:geo_id>238</gn:geo_id> <gn:geo_name

xml:lang="pt">Porto</gn:geo_name>

<gn:geo_type_id rdf:resource="#CON"/>

<gn:info_source_id rdf:resource="#INE"/> <gn:related_to> <rdf:Bag> <rdf:li> <gn:Geo_Relationship>

<gn:rel_type_id rdf:resource="#PRT"/> <gn:geo_id><rdf:Bag>

<rdf:li rdf:resource="#GEO_130"/>

<rdf:li rdf:resource="#GEO_3967"/> </rdf:Bag></gn:geo_id> </gn:Geo_Relationship> </rdf:li>

<rdf:li><gn:Geo_Relationship> <gn:rel_type_id rdf:resource="#ADJ"/> <gn:geo_id> <rdf:Bag>

<rdf:li rdf:resource="#GEO_127"/> <rdf:li rdf:resource="#GEO_156"/> <rdf:li rdf:resource="#GEO_162"/> <rdf:li rdf:resource="#GEO_331"/> </rdf:Bag> </gn:geo_id> </gn:Geo_Relationship></rdf:li> </rdf:Bag> </gn:related_to> <gn:population>263131</gn:population></gn:Geo_Feature>

• Geo-Net-PT01


Statistics of the Ontologies Created

Statistic Portugal World

# of features 418,065 12,293

# of relationships 419,867 12,258

# of part-of relationships 418,340 (99.83%) 12,245 (99,89%)

# of equivalence relationships 395 (0.09%) 2,501(20,40%)

# of adjacency relationships 1,132 (0.27%) 13 (0.10%)

Avg. broader features per feature 1.0016 1.07

Avg. narrower features per feature 10.56 475.44

Avg. equivalent features per feature with equivalent 1.99 3.82

Avg. adjacent features per feature with adjacent 3.54 6.5

# of features without ancestors 3 (0.00%) 1(0.00%)

# of features without descendants 374,349 (89.54%) 12,045 (97,98%)

# of features without equivalent 417,867 (99.95%) 11,819 (96,14%)

# of features without adjacent 417,739 (99.92%) 12,291 (99,99%)





Applications using GKB

• NERC tool for recognizing geographical references in text

• Classification tool for assigning documents to a corresponding geographical scope

• Information retrieval interface for geographical queries


Applications using GKB


Final Remarks

• A domain-independent model for storing geographic and network knowledge

• Sharing of the collected knowledge as formal ontologies

• Geo-Net-PT01: The first public geographic ontology of Portugal - http://xldb.fc.ul.pt/geonetpt

• Future work– Augmenting the knowledge in GKB with geographic

entities extracted from the texts of the Portuguese Web

http://xldb.fc.ul.pt/geonetpt

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Simpósio Brasileiro de Banco de Dados 2005

Technology