Data Models and Query Languagesfor Linked Geospatial DataReasoning Web 2012Dept. of Informatics and TelecommunicationsNati...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Tutorial Organization14:30 – ...
IntroductionPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodis...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Outline• Why should you be in...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Why Geospatial Information?• ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Geography• From http://en.wik...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Geographical Information Syst...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Combining GIS Data for Decisi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Why this tutorial?• Lots of g...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10Geospatial data on the Web
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11Open Government Data
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12Linked geospatial data –Ordn...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13Linked geospatial data –Rese...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14Linked geospatial data – Spain
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Linked geospatial data – Ope...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16Conclusions• Introduction• W...
Background in geospatial datamodelingPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and Telecommunica...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Outline• Basic GIS concepts a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Basic GIS Concepts and Termin...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Basic GIS Concepts (cont’d)• ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Basic GIS Concepts (cont’d)• ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Basic GIS Concepts (cont’d)• ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Geometric Information• Geomet...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Topological Information• Topo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Topological Relations• The st...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10The 4-intersection model• Th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data114IM and 9IM• The 4-intersect...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12DE-9IM• The dimensionally ex...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13DE-9IM• It captures topologi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14DE-9IM• Five jointly exclusi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Example: A disjoint CI(C) B(...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16Example: A within CI(C) B(C)...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data17DE-9IM Relation Definitions
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18The Region Connection Calcul...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data19RCC-8• This is a set of eigh...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20RCC-5• The RCC-5 subset has ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21More Qualitative Spatial Rel...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22Coordinate Systems• Coordina...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Coordinate Reference Systems...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data24Geographic Coordinate Refere...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data25The World Geodetic System• T...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data26Projected Coordinate Referen...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data27Coordinate Reference Systems...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data28Geographic Space Modeling Pa...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data29Abstract Modeling Paradigms:...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data30Abstract Modeling Paradigms:...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data31From Abstract Modeling to Co...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data32Approximations: Tessellation...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data33Example• Cadastral map (irre...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data34Special Encodings:Vector Rep...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data35Example[(1,2) (2,2) (5,3) (3...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data36Special Encodings:Constraint...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data37Constraint Databases• The co...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data38Geospatial Data Standards• T...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data39Well-Known Text (WKT)• WKT i...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data40WKT Class Hierarchy
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data41ExampleWKT representation:Ge...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data42Geography Markup Language (G...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data43GML Simple Features:Class Hi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data44ExampleGML representation:<g...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data45OpenGIS Simple Features Acce...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data46OpenGIS Simple Features Acce...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data47SQL with Geometry Types -Fun...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data48SQL with Geometry Types –Fun...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data49DE-9IM Relation Definitions•...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data50SQL with Geometry Types –Fun...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data51Geospatial Relational DBMS• ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data52Conclusions• Background in g...
Geospatial data in RDF –stSPARQLPresenter: Kostis KyzirakosReasoning Web 2012Dept. of Informatics and TelecommunicationsNa...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Outline Main idea Early wor...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Main ideaHow do we represent ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Early worksSPAUK Geometric a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Early worksSPARQL-ST Assumes...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6stRDF and stSPARQL Similar a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Example
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Example with simplified geome...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Example in stRDFgeonames:Olym...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10strdf:geometry rdf:type rdfs...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11We define the datatypes strd...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12 Value space: the set of ge...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13Examples of publicly availab...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14Geonames
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Geonames
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeonamesgn:2761333rdf:type geo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data17Greek Administrative Geograp...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18Greek Administrative Geograp...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Datagag:Olympiardf:type gag:Commun...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20Corine Land Use / Land Cover
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21Corine Land Use / Land Cover
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22Corine Land Use / Land Cover...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Burnt Area Products
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data24Burnt Area Products
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data25Burnt Area Productsnoa:ba_15...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data26stSPARQL: Geospatial SPARQL ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data27stSPARQL: Geospatial SPARQL ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data28stSPARQL: Geospatial SPARQL ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data29stSPARQL: Geospatial SPARQL ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data30stSPARQL: An example (1/3)SE...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data31stSPARQL: An example (2/3)SE...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSpatialFunction32SELECT ?burnt...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data33Conclusions Geospatial data...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography34[Kolas and Self,...
Geospatial data in RDF –GeoSPARQLPresenter: Kostis KyzirakosReasoning Web 2012Dept. of Informatics and TelecommunicationsN...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2GeoSPARQLGeoSPARQL is a recen...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Example in GeoSPARQL (1/2)geo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Example in GeoSPARQL (2/2)gag...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeoSPARQL ComponentsCoreTopolo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6GeoSPARQL CoreDefines top lev...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7ExampleGeoSPARQL representati...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8GeoSPARQL Geometry ExtensionP...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9ExampleGeoSPARQL representati...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10GeoSPARQL Geometry Extension...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11GeoSPARQL Topology Vocabular...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Datagag:Olympiardf:type gag:Commun...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13GeoSPARQL: An exampleSELECT ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14GeoSPARQL: An exampleSELECT ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Example (cont’d)The answer t...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16GeoSPARQL Geometry Topology ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Provides a mechanism for rea...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18ExampleGiven the triplesex:f...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data19GeoSPARQL Query Rewrite Exte...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20RIF RuleForall ?f1 ?f2 ?g1 ?...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21GeoSPARQL: An exampleSELECT ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22GeoSPARQL: An exampleSELECT ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Conclusions Geospatial data...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography24[Perry and Herri...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataImplemented RDF Stores withGeo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataOutline Relational DBMS with ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Geometries are not explicitl...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSpecial indices needed for geo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataWill examine following aspects...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Strabon Parliament Brodt e...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Storage and query evaluation...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataStrabon - Implementation8stRDF...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Storage Engine Developed by...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Rule engine included Paired...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Built on top of RDF-3X Impl...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataFocus on spatial queryprocessi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Built on top of Oracle 10g ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Spatiotemporal operators imp...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data AllegroGraph OWLIM Virtuos...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Well-known RDF store, develo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Semantic Repository, develop...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Multi-model data server, dev...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Add-on library for Sesame-en...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSystem Language Index Geometri...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21Conclusions Semantic Geospa...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography22[Kyzirakos et al...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography23[Brodt et al, 20...
Geospatial Information withDescription Logics, OWL, andRulesPresenter: Charalampos NikolaouReasoning Web 2012Dept. of Info...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataOutline§  Geospatial informat...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with DL...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is4
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is5Use OWL-DL§...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is7Use OWL-DLDi...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataDefine a spatial DL(concrete d...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConcrete domains§  Reason abo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConcrete domainsExamples:§  R...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTBoxConcept equivalences/inclu...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTwo state of the art approache...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTwo state of the art approache...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne th...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§ ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox30
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox31Ge...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox32Ge...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox33Ge...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox341....
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox35Do...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox36RC...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox38Ap...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataThe reasoner RacerPro39§  Des...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data40§  Spatial regions: a, b, a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data41§  Spatial regions: a, b, a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data42§  Spatial regions: a, b, a...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataRacerPro: ABox Reasoning43§  ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataDream House (definition)§  Dr...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  DreamHouseOne that is loca...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  DreamHouseOne that is loca...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox47Dream House (ABox re...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data51Dream House (ABox reasoning)
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data52NTPPDream House (ABox reason...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data53NTPPECDream House (ABox reas...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data54NTPPNTPPECDream House (ABox ...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data55NTPPECComposition of edge(vh...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data56NTPPECComposition of edge(vh...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data57NTPPPO, TPP, NTPPECNTPPDream...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data58NTPPPO, TPP, NTPPECNTPPDream...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataThe reasoner PelletSpatial59§...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSWRL Rules60
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataModelingGeospatial information...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConclusions75§  We talked abo...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography76[Katz et al., OW...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography77[Wessel-Möller, ...
ConclusionsPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodist...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2What we talked about Introdu...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3What we did not talk about: T...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4What we did not talk about:Re...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5What we did not talk about: T...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Some open research questions•...
Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Thank you for Attending!• Que...
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Data Models and Query Languages for Linked Geospatial Data

  1. 1. Data Models and Query Languagesfor Linked Geospatial DataReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer SchoolManolis Koubarakis, Kostis Kyzirakos andCharalampos Nikolaou
  2. 2. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Tutorial Organization14:30 – 14:45 Introduction14:45 – 15:15 Background in geospatial data modeling15:15 – 16:00 Geospatial data in RDF - stSPARQL16:00 – 16:30 Coffee break16:30 – 16:45 Geospatial data in RDF - GeoSPARQL16:45 – 17:00 Implemented RDF Stores with geospatial support17:00 – 17:50 Geospatial information with description logics, OWLand rules17:50 – 18:00 Conclusions, questions, discussion
  3. 3. IntroductionPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  4. 4. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Outline• Why should you be interested ingeospatial information?• Why should you attend this tutorial?
  5. 5. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Why Geospatial Information?• Geospatial, and in general geographical, information is veryimportant in reality: everything that happens, happenssomewhere (location).• Decision making can be substantially improved if we knowwhere things take place.
  6. 6. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Geography• From http://en.wikipedia.org/wiki/Geography• Geography is the science that studies the lands,the features, the inhabitants and the phenomena ofthe Earth.• From the Greek word γεωγραφία (geographia)which means “describing the Earth”.
  7. 7. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Geographical Information Systemsand Science• A geographical information system (GIS) is a system designed to capture,store, manipulate, analyze, manage, and present all types of geographicaldata.• GIS science is the field of study for developing and using GIS.
  8. 8. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Combining GIS Data for Decision Making
  9. 9. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Why this tutorial?• Lots of geospatial data is available on the Webtoday.• Lots of public data coming out of open governmentinitiatives is geospatial.• Lots of the above data is quickly being transformedinto linked data!• People have started building applications utilizinglinked data.
  10. 10. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10Geospatial data on the Web
  11. 11. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11Open Government Data
  12. 12. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12Linked geospatial data –Ordnance Survey
  13. 13. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13Linked geospatial data –Research Funding Explorer
  14. 14. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14Linked geospatial data – Spain
  15. 15. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Linked geospatial data – Open Street Map
  16. 16. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16Conclusions• Introduction• Why should you be interested ingeospatial information?• Why should you attend this tutorial?• Next topic: Background in geospatialdata modeling
  17. 17. Background in geospatial datamodelingPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  18. 18. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Outline• Basic GIS concepts and terminology• Geographic space modeling paradigms• Geospatial data standards
  19. 19. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Basic GIS Concepts and Terminology• Theme: the information corresponding to a particular domainthat we want to model. A theme is a set of geographicfeatures.• Example: the countries of Europe
  20. 20. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Basic GIS Concepts (cont’d)• Geographic feature or geographic object: a domain entitythat can have various attributes that describe spatial and non-spatial characteristics.• Example: the country Greece with attributes• Population• Flag• Capital• Geographical area• Coastline• Bordering countries
  21. 21. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Basic GIS Concepts (cont’d)• Geographic features can be atomic or complex.• Example: According to the Kallikratis administrative reform of2010, Greece consists of:• 13 regions (e.g., Crete)• Each region consists of perfectures (e.g., Heraklion)• Each perfecture consists of municipalities (e.g., DimosChersonisou)
  22. 22. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Basic GIS Concepts (cont’d)• The spatial characteristics of a feature can involve:• Geometric information (location in the underlyinggeographic space, shape etc.)• Topological information (containment, adjacency etc.).Municipalities of the perfecture ofHeraklion:1. Dimos Irakliou2. Dimos Archanon-Asterousion3. Dimos Viannou4. Dimos Gortynas5. Dimos Maleviziou6. Dimos Minoa Pediadas7. Dimos Festou8. Dimos Chersonisou
  23. 23. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Geometric Information• Geometric information can be captured by using geometric primitives(points, lines, polygons, etc.) to approximate the spatial attributes ofthe real world feature that we want to model.• Geometries are associated with a coordinate reference system whichdescribes the coordinate space in which the geometry is defined.
  24. 24. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Topological Information• Topological information is inherently qualitative and it isexpressed in terms of topological relations (e.g., containment,adjacency, overlap etc.).• Topological information can be derived from geometricinformation or it might be captured by asserting explicitly thetopological relations between features.
  25. 25. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Topological Relations• The study of topological relations has produceda lot of interesting results by researchers in:• GIS• Spatial databases• Artificial Intelligence (qualitative reasoningand knowledge representation)
  26. 26. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10The 4-intersection model• The 4-intersection model has been defined by Egenhofer andFranzosa in 1991 based on previous work by Egenhofer andcolleagues.• It is based on point-set topology.• Spatial regions are defined to be non-empty, proper subsetsof a topological space. In addition, they must be closed andhave connected interiors.• Topological relations are the ones that are invariant undertopological homeomorphisms.
  27. 27. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data114IM and 9IM• The 4-intersection model can captures topological relationsbetween two spatial regions a and b by considering whether theintersection of their boundaries and interiors is empty ornon-empty.• The 9-intersection model is an extension of the 4-intersectionmodel (Egenhofer and Herring, 1991).• 9IM captures topological relations between two spatial regions aand b by considering whether the intersection of their boundaries,interiors and exteriors is empty or non-empty.
  28. 28. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12DE-9IM• The dimensionally extended 9-intersection modelhas been defined by Clementini and Felice in 1994.• It is also based on the point-set topology of R2 anddeals with “simple”, closed geometries (areas,lines, points).• Like its predecessors (4IM, 9IM), it can also beextended to more complex geometries (areas withholes, geometries with multiple components).
  29. 29. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13DE-9IM• It captures topological relationships between twogeometries a and b in R2 by considering thedimensions of the intersections of theboundaries, interiors and exteriors of the twogeometries:• The dimension can be 2, 1, 0 and -1 (dimension ofthe empty set).
  30. 30. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14DE-9IM• Five jointly exclusive and pairwise disjoint (JEPD)relationships between two different geometries can bedistinguished (disjoint, touches, crosses, within, overlaps).• The model can also be defined using an appropriate calculus ofgeometries that uses these 5 binary relations and boundaryoperators.• See the paper: E. Clementini and P. Felice. A Comparison ofMethods for Representing Topological Relationships. InformationSciences 80 (1994), pp. 1-34.
  31. 31. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Example: A disjoint CI(C) B(C) E(C)I(A) F F *B(A) F F *E(A) * * *ACNotation:• T = { 0, 1, 2 }• F = -1• * = don’t care = { -1, 0, 1, 2 }
  32. 32. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16Example: A within CI(C) B(C) E(C)I(A) T * FB(A) * * FE(A) * * *CANotation equivalent to 3x3matrix:• String of 9 charactersrepresenting the above matrix inrow major order.• In this case: T*F**F***
  33. 33. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data17DE-9IM Relation Definitions
  34. 34. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18The Region Connection Calculus (RCC)• The primitives of the calculus are spatial regions. These arenon-empty, regular subsets of a topological space.• The calculus is based on a single binary predicate C thatformalizes the “connectedness” relation.• C(a,b) is true when the closure of a is connected to theclosure of b i.e., they have at least one point in common.• It is axiomatized using first order logic.• See the original paper by Randell, Cui and Cohn (KR 1991).
  35. 35. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data19RCC-8• This is a set of eight JEPD binary relationsthat can be defined in terms of predicate C.
  36. 36. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20RCC-5• The RCC-5 subset has also been studied. Thegranularity here is coarser. The boundary of a region isnot taken into consideration:• No distinction among DC and EC, called just DR.• No distinction among TPP and NTPP, called justPP.• RCC-8 and RCC-5 relations can also be definedusing point-set topology, and there are very closeconnections to the models of Egenhofer and others.
  37. 37. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21More Qualitative Spatial Relations• Orientation/Cardinal directions (left of, right of,north of, south of, northeast of etc.)• Distance (close to, far from etc.). This informationcan also be quantitative.
  38. 38. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22Coordinate Systems• Coordinate: one of n scalar values that determines the positionof a point in an n-dimensional space.• Coordinate system: a set of mathematical rules for specifyinghow coordinates are to be assigned to points.• Example: the Cartesian coordinate system
  39. 39. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Coordinate Reference Systems• Coordinate reference system: a coordinate systemthat is related to an object (e.g., the Earth, a planarprojection of the Earth, a three dimensionalmathematical space such as R3) through a datumwhich specifies its origin, scale, and orientation.• The term spatial reference system is also used.
  40. 40. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data24Geographic Coordinate Reference Systems• These are 3-dimensional coordinate systems that utilize latitude(φ), longitude (λ) , and optionally geodetic height (i.e.,elevation), to capture geographic locations on Earth.
  41. 41. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data25The World Geodetic System• The World Geodetic System (WGS) is the most well-knowngeographic coordinate reference system and its latest revision isWGS84.• Applications: cartography, geodesy, navigation (GPS), etc.
  42. 42. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data26Projected Coordinate Reference Systems• Projected coordinate reference system: they transform the 3-dimensional approximation of the Earth into a 2-dimensionalsurface (distortions!)• Example: the Universal Transverse Mercator (UTM) system
  43. 43. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data27Coordinate Reference Systems (cont’d)• There are well-known ways to translate between co-ordinate reference systems.• Various authorities maintain lists of coordinatereference systems. See for example:• OGC http://www.opengis.net/def/crs/• European Petroleum Survey Grouphttp://www.epsg-registry.org/
  44. 44. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data28Geographic Space Modeling Paradigms• Abstract geographic space modelingparadigms: discrete objects vs. continuousfields• Concrete representations: tessellation vs.vectors vs. constraints
  45. 45. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data29Abstract Modeling Paradigms:Feature-based• Feature-based (or entity-based or object-based). This kind ofmodeling is based on the concepts we presented already.
  46. 46. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data30Abstract Modeling Paradigms:Field-based• Each point (x,y) in geographic space is associated with one orseveral attribute values defined as continuous functions in xand y.• Examples: elevation, precipitation, humidity, temperature foreach point (x,y) in the Euclidean plane.
  47. 47. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data31From Abstract Modeling to ConcreteRepresentations• Question: How do we represent the infinite objects of theabstract representations (points, lines, fields etc.) by finitemeans (in a computer)?• Answers:• Approximate the continuous space (e.g., ℝ2) by a discreteone (ℤ2).• Use special encodings
  48. 48. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data32Approximations: Tessellation• In this case a cellular decomposition of the plane (usually, agrid) serves as a basis for representing the geometry.• Example: raster representation (fixed or regular tesselation)
  49. 49. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data33Example• Cadastral map (irregular tessellation) overlayed on a satelliteimage.
  50. 50. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data34Special Encodings:Vector Representation• In this case objects in space are represented using points asprimitives as follows:• A point is represented by a tuple of coordinates.• A line segment is represented by a pair with its beginningand ending point.• More complex objects such as arbitrary lines, curves,surfaces etc. are built recursively by the basic primitivesusing constructs such as lists, sets etc.• This is the approach used in all GIS and other popularsystems today. It has also been standardized by variousinternational bodies.
  51. 51. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data35Example[(1,2) (2,2) (5,3) (3,1) (2,1) (1 2)]
  52. 52. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data36Special Encodings:Constraint Representation• In this case objects in space are represented by quantifier freeformulas in a constraint language (e.g., linear constraints).)34353()124()223( ≤−∧≤∧≥∨≥∧≥∧≤+∨≤∧≤∧≥+xyxyyxxyyxxy
  53. 53. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data37Constraint Databases• The constraint representation of spatial data was the focus ofmuch work in databases, logic programming and AI after thepaper by Kanellakis, Kuper and Revesz (PODS, 1991).• The approach was very fruitful theoretically but was not adoptedin practice.• See the book by Revesz for a tutorial introduction.
  54. 54. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data38Geospatial Data Standards• The Open Geospatial Consortium (OGC) and theInternational Organization for Standardization (ISO) havedeveloped many geospatial data standards that are in wide usetoday. In this tutorial we will cover:• Well-Known Text• Geography Markup Language• OpenGIS Simple Feature Access
  55. 55. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data39Well-Known Text (WKT)• WKT is an OGC and ISO standard for representing geometries,coordinate reference systems, and transformations betweencoordinate reference systems.• WKT is specified in OpenGIS Simple Feature Access - Part 1:Common Architecture standard which is the same as the ISO 19125-1standard. Download fromhttp://portal.opengeospatial.org/files/?artifact_id=25355 .• This standard concentrates on simple features: features with allspatial attributes described piecewise by a straight line or aplanar interpolation between sets of points.
  56. 56. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data40WKT Class Hierarchy
  57. 57. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data41ExampleWKT representation:GeometryCollection(Point(5 35),LineString(3 10,5 25,15 35,20 37,30 40),Polygon((5 5,28 7,44 14,47 35,40 40,20 30,5 5),(28 29,14.5 11,26.5 12,37.5 20,28 29)))
  58. 58. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data42Geography Markup Language (GML)• GML is an XML-based encoding standard for therepresentation of geospatial data.• GML provides XML schemas for defining a variety of concepts:geographic features, geometry, coordinate referencesystems, topology, time and units of measurement.• GML profiles are subsets of GML that target particularapplications.• Examples: Point Profile, GML Simple Features Profile etc.
  59. 59. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data43GML Simple Features:Class Hierarchy
  60. 60. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data44ExampleGML representation:<gml:Polygon gml:id="p3" srsName="urn:ogc:def:crs:EPSG:6.6:4326”><gml:exterior><gml:LinearRing><gml:coordinates>5,5 28,7 44,14 47,35 40,40 20,30 5,5</gml:coordinates></gml:LinearRing></gml:exterior></gml:Polygon>
  61. 61. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data45OpenGIS Simple Features Access(cont’d)• OGC has also specified a standard for the storage, retrieval,query and update of sets of simple features usingrelational DBMS and SQL.• This standard is “OpenGIS Simple Feature Access - Part 2: SQLOption” and it is the same as the ISO 19125-2 standard. Download fromhttp://portal.opengeospatial.org/files/?artifact_id=25354.• Related standard: ISO 13249 SQL/MM - Part 3.
  62. 62. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data46OpenGIS Simple Features Access(cont’d)• The standard covers two implementations options: (i) using onlythe SQL predefined data types and (ii) using SQL withgeometry types.• SQL with geometry types:• We use the WKT geometry class hierarchy presented earlierto define new geometric data types for SQL• We define new SQL functions on those types.
  63. 63. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data47SQL with Geometry Types -Functions• Functions that request or check properties of a geometry:• ST_Dimension(A:Geometry):Integer• ST_GeometryType(A:Geometry):Character Varying• ST_AsText(A:Geometry): Character Large Object• ST_AsBinary(A:Geometry): Binary Large Object• ST_SRID(A:Geometry): Integer• ST_IsEmpty(A:Geometry): Boolean• ST_IsSimple(A:Geometry): Boolean
  64. 64. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data48SQL with Geometry Types –Functions (cont’d)• Functions that test topological relations between two geometriesusing the DE-9IM:• ST_Equals(A:Geometry, B:Geometry):Boolean• ST_Disjoint(A:Geometry, B:Geometry):Boolean• ST_Intersects(A:Geometry, B:Geometry):Boolean• ST_Touches(A:Geometry, B:Geometry):Boolean• ST_Crosses(A:Geometry, B:Geometry):Boolean• ST_Within(A:Geometry, B:Geometry):Boolean• ST_Contains(A:Geometry, B:Geometry):Boolean• ST_Overlaps(A:Geometry, B:Geometry):Boolean• ST_Relate(A:Geometry, B:Geometry, Matrix: Char(9)):Boolean
  65. 65. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data49DE-9IM Relation Definitions• A equals B can also bedefined by the patternTFFFTFFFT.• A intersects B is thenegation of A disjoint B• A contains B is equivalentto B within A
  66. 66. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data50SQL with Geometry Types –Functions (cont’d)• Functions for constructing new geometries out of existingones:• ST Boundary(A:Geometry):Geometry• ST_Envelope(A:Geometry):Geometry• ST_Intersection(A:Geometry, B:Geometry):Geometry• ST_Union(A:Geometry, B:Geometry):Geometry• ST_Difference(A:Geometry, B:Geometry):Geometry• ST_SymDifference(A:Geometry, B:Geometry):Geometry• ST_Buffer(A:Geometry, distance:Double):Geometry
  67. 67. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data51Geospatial Relational DBMS• The OpenGIS Simple Features Access Standard is today beenused in all relational DBMS with a geospatial extension.• The abstract data type mechanism of the DBMS allowsthe representation of all kinds of geospatial data typessupported by the standard.• The query language (SQL) offers the functions of thestandard for querying data of these types.
  68. 68. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data52Conclusions• Background in geospatial data modeling:• Why geographical information?• Geographical Information Science and Systems• Geospatial data on the Web and linked geospatial data• Abstract geographic space modeling paradigms: discreteobjects vs. continuous fields• Concrete representations: tessellation vs. vectors vs.constraints• Geospatial data standards• Next topic: Geospatial data in the Semantic Web
  69. 69. Geospatial data in RDF –stSPARQLPresenter: Kostis KyzirakosReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  70. 70. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2Outline Main idea Early works The data model stRDF Examples of publicly available linkedgeospatial data The query language stSPARQL
  71. 71. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Main ideaHow do we represent and query geospatialinformation in the Semantic Web?Extend RDF to take into account thegeospatial dimension.Extend SPARQL to query the new kinds ofdata.
  72. 72. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Early worksSPAUK Geometric attributes of a resource are represented by:• introducing a blank node for the geometry• specifying the geometry using GML vocabulary• associating the blank node with the resourceusing GeoRSS vocabulary Queries are expressed in SPARQL utilizing appropriategeometric vocabularies and ontologies (e.g., thetopological relationships of RCC-8). Introduces a new PREMISE clause in SPARQL to specifyspatial geometries to be used in a query Use some form of the DESCRIBE query form of SPARQLfor asking queries about geometries
  73. 73. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5Early worksSPARQL-ST Assumes a particular upper ontologyexpressed in RDFS for modeling theme,space and valid time. Spatial geometries in SPARQL-ST arespecified by sets of RDF triples that givevarious details of the geometry. SPARQL-ST provides a set of built-in spatialconditions that can be used in SPATIALFILTER clauses to constrain the geometriesthat are returned as answers to queries.
  74. 74. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6stRDF and stSPARQL Similar approach to SPARQL-ST(theme, space and valid timecan be represented) Linear constraints are used to representgeometries Constraints are represented using literals ofan appropriate datatype Formal approach New version to be presented today uses OGCstandards to represent and querygeometries
  75. 75. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Example
  76. 76. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8Example with simplified geometries
  77. 77. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9Example in stRDFgeonames:Olympiageonames:name "Ancient Olympia";owl:sameAs dbpedia:Olympia_Greece;rdf:type dbpedia:Community .Spatialdata typegeonames:Olympia strdf:hasGeometry"POLYGON((21.5 18.5, 23.5 18.5,23.5 21, 21.5 21, 21.5 18.5));<http://www.opengis.net/def/crs/EPSG/0/4326>"^^strdf:WKT .Spatialliteral
  78. 78. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10strdf:geometry rdf:type rdfs:Datatype;rdfs:subClassOf rdfs:Literal.strdf:WKT rdf:type rdfs:Datatype;rdfs:subClassOf rdfs:Literal;rdfs:subClassOf strdf:geometry.strdf:GML rdf:type rdfs:Datatype;rdfs:subClassOf rdfs:Literal;rdfs:subClassOf strdf:geometry.The stRDF Data Model
  79. 79. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11We define the datatypes strdf:WKT and strdf:GMLthat can be used to represent spatial objectsusing the WKT and GML serializations. Lexical space: the finite length sequences ofcharacters that can be produced from the WKT andGML specifications. Literals of type strdf:WKT consist of an optional URIidentifying the coordinate reference system used.The stRDF Data Modele.g., "POINT(21 18);<http://www.opengis.net/def/crs/EPSG/0/4326>"^^strdf:WKT
  80. 80. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data12 Value space: the set of geometry values definedin the WKT and GML standard that is a subset ofthe powerset of ℝ2and ℝ3. Lexical-to-value mapping: takes into accountthat the vector-based model is used forrepresenting geometries. The datatype strdf:geometry is the union ofthe datatypes strdf:WKT and strdf:GML.The stRDF Data Model
  81. 81. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13Examples of publicly availablelinked geospatial data Geonames Greek Administrative Geography Corine Land Use / Land Cover Burnt Area Products
  82. 82. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14Geonames
  83. 83. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Geonames
  84. 84. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeonamesgn:2761333rdf:type geonames:Feature;geonames:officialName "Vienna"@en;geonames:name "Politischer Bezirk Wien (Stadt)";geonames:countryCode "AT";wgs84_pos:lat "48.2066";wgs84_pos:long "16.37341".geonames:parentCountry gn:2782113;gn:2782113geonames:name "Austria";geonames:altName "Republic of Austria"@en,"Republik Osterreich"@de,"Αυστρία"@el.
  85. 85. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data17Greek Administrative GeographyKallikrates ontology
  86. 86. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18Greek Administrative GeographyKallikrates ontology
  87. 87. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Datagag:Olympiardf:type gag:Community;geonames:name "Ancient Olympia";gag:population "184"^^xsd:int;strdf:hasGeometry "POLYGON(((25.37 35.34,…)))"^^strdf:WKT.gag:OlympiaBoroughrdf:type gag:Borough;rdfs:label "Borough ofAncient Olympia".gag:OlympiaMunicipalityrdf:type gag:Municipality;rdfs:label "Municipality ofAncient Olympia".gag:Olympia gag:isPartOf gag:OlympiaBorough .gag:OlympiaBorough gag:isPartOf gag:OlympiaMunicipality.19Greek Administrative Geography
  88. 88. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20Corine Land Use / Land Cover
  89. 89. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21Corine Land Use / Land Cover
  90. 90. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22Corine Land Use / Land Covernoa:Area_24015134rdf:type noa:Area ;noa:hasCode "312"^^xsd:decimal;noa:hasID "EU-203497"^^xsd:string;noa:hasArea_ha "255.5807904"^^xsd:double;strdf:hasGeometry "POLYGON((15.53 62.54,…))"^^strdf:WKT;noa:hasLandUse noa:ConiferousForest
  91. 91. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Burnt Area Products
  92. 92. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data24Burnt Area Products
  93. 93. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data25Burnt Area Productsnoa:ba_15rdf:type noa:BurntArea;noa:isProducedByProcessingChain"static thresholds"^^xsd:string;noa:hasAcquisitionTime"2010-08-24T13:00:00"^^xsd:dateTime;strdf:hasGeometry "MULTIPOLYGON(((393801.42 4198827.92, ..., 393008 424131)));<http://www.opengis.net/def/crs/EPSG/0/2100>"^^strdf:WKT.
  94. 94. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data26stSPARQL: Geospatial SPARQL 1.1We define a SPARQL extension function for each functiondefined in the OpenGIS Simple Features Access standardBasic functions Get a property of a geometryxsd:int strdf:Dimension(strdf:geometry A)xsd:string strdf:GeometryType(strdf:geometry A)xsd:int strdf:SRID(strdf:geometry A) Get the desired representation of a geometryxsd:string strdf:AsText(strdf:geometry A)strdf:wkb strdf:AsBinary(strdf:geometry A)xsd:string strdf:AsGML(strdf:geometry A) Test whether a certain condition holdsxsd:boolean strdf:IsEmpty(strdf:geometry A)xsd:boolean strdf:IsSimple(strdf:geometry A)
  95. 95. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data27stSPARQL: Geospatial SPARQL 1.1Functions for testing topological spatialrelationships OGC Simple Features Accessxsd:boolean strdf:Equals(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Disjoint(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Intersects(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Touches(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Crosses(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Within(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Contains(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Overlaps(strdf:geometry A, strdf:geometry B)xsd:boolean strdf:Relate(strdf:geometry A, strdf:geometry B,xsd:string intersectionPatternMatrix) Egenhofer RCC-8
  96. 96. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data28stSPARQL: Geospatial SPARQL 1.1Spatial analysis functions Construct new geometric objects from existing geometricobjectsstrdf:geometry strdf:Boundary(strdf:geometry A)strdf:geometry strdf:Envelope(strdf:geometry A)strdf:geometry strdf:Intersection(strdf:geometry A, strdf:geometry B)strdf:geometry strdf:Union(strdf:geometry A, strdf:geometry B)strdf:geometry strdf:Difference(strdf:geometry A, strdf:geometry B)strdf:geometry strdf:SymDifference(strdf:geometry A, strdf:geometry B)strdf:geometry strdf:Buffer(strdf:geometry A, xsd:double distance) Spatial metric functionsxsd:float strdf:distance(strdf:geometry A, strdf:geometry B)xsd:float strdf:area(strdf:geometry A) Spatial aggregate functionsstrdf:geometry strdf:Union(set of strdf:geometry A)strdf:geometry strdf:Intersection(set of strdf:geometry A)strdf:geometry strdf:Extent(set of strdf:geometry A)
  97. 97. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data29stSPARQL: Geospatial SPARQL 1.1Select clause Construction of new geometries (e.g., strdf:buffer(?geo, 0.1)) Spatial aggregate functions (e.g., strdf:union(?geo)) Metric functions (e.g., strdf:area(?geo))Filter clause Functions for testing topological spatial relationships between spatial terms(e.g., strdf:contains(?G1, strdf:union(?G2, ?G3))) Numeric expressions involving spatial metric functions(e.g., strdf:area(?G1) ≤ 2*strdf:area(?G2)+1) Boolean combinationsHaving clause Boolean expressions involving spatial aggregate functions and spatialmetric functions or functions testing for topological relationships betweenspatial terms (e.g., strdf:area(strdf:union(?geo))>1)
  98. 98. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data30stSPARQL: An example (1/3)SELECT ?nameWHERE {?community rdf:type dbpedia:Community;geonames:name ?name;strdf:hasGeometry ?comGeom.?ba rdf:type noa:BurntArea;strdf:hasGeometry ?baGeom.FILTER(strdf:overlap(?comGeom,?baGeom))}SpatialFunctionReturn the names of communities that have beenaffected by fires
  99. 99. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data31stSPARQL: An example (2/3)SELECT ?ba ?baGeomWHERE {?r rdf:type noa:Region;strdf:geometry ?rGeom;noa:hasCorineLandCoverUse ?f.?f rdfs:subClassOf clc:Forests.?c rdf:type dbpedia:Community;strdf:geometry ?cGeom.?ba rdf:type noa:BurntArea;strdf:geometry ?baGeom.FILTER( strdf:intersects(?rGeom,?baGeom) &&strdf:distance(?baGeom,?cGeom) < 0.02)}SpatialFunctionsFind all burnt forests near communities
  100. 100. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSpatialFunction32SELECT ?burntArea(strdf:intersection(?baGeom,strdf:union(?fGeom))AS ?burntForest)WHERE {?burntArea rdf:type noa:BurntArea;strdf:hasGeometry ?baGeom.?forest rdf:type noa:Region;noa:hasLandCover noa:coniferousForest;strdf:hasGeometry ?fGeom.FILTER(strdf:intersects(?baGeom,?fGeom))}GROUP BY ?burntArea ?baGeomIsolate the parts of the burnt areas that lie inconiferous forests.stSPARQL: An example 3/3)SpatialAggregate
  101. 101. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data33Conclusions Geospatial data in the Semantic Web - stSPARQL Early works The data model stRDF Examples of publicly available linked geospatialdata The query language stSPARQL Next topic: Geospatial data in RDF - GeoSPARQL
  102. 102. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography34[Kolas and Self, 2007]Kolas, D., Self, T.: Spatially Augmented Knowledgebase. In:Proceedings of the 6th International Semantic Web Conference and2nd Asian Semantic Web Conference (ISWC/ASWC2007). LectureNotes in Computer Science, vol. 4825, pp. 785-794. SpringerVerlag (2007)[Perry, 2008]Perry, M.: A Framework to Support Spatial, Temporal and ThematicAnalytics over Semantic Web Data. Ph.D. thesis, Wright StateUniversity (2008)[Koubarakis and Kyzirakos, 2010]Koubarakis, M., Kyzirakos, K.: Modeling and Querying Metadata in theSemantic Sensor Web: The Model stRDF and the Query LanguagestSPARQL. In: ESWC. pp. 425-439 (2010)
  103. 103. Geospatial data in RDF –GeoSPARQLPresenter: Kostis KyzirakosReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  104. 104. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2GeoSPARQLGeoSPARQL is a recently completedOGC standardFunctionalities similar to stSPARQL: Geometries are represented using literalssimilarly to stSPARQL. The same families of functions are offered forquerying geometries.Functionalities beyond stSPARQL: Topological relations can now be asserted aswell so that reasoning and querying on them ispossible.
  105. 105. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3Example in GeoSPARQL (1/2)geonames:Olympiageonames:name "Ancient Olympia";rdf:type dbpedia:Community ;geo:hasGeometry ex:polygon1.ex:polygon1rdf:type geo:Polygon;geo:asWKT "POLYGON((21.5 18.5,23.5 18.5,23.5 21,21.5 21,21.5 18.5))"^^sf:wktLiteral.Spatialdata typeSpatialliteral
  106. 106. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4Example in GeoSPARQL (2/2)gag:OlympiaMunicipalityrdf:type gag:Municipality;rdfs:label "ΔΗΜΟΣ ΑΡΧΑΙΑΣΟΛΥΜΠΙΑΣ"@el;rdfs:label "Municipality ofAncient Olympia".Assertedtopologicalrelationgag:olympiaMunicipality geo:sfContains geonames:olympia .
  107. 107. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeoSPARQL ComponentsCoreTopology VocabularyExtension- relation familyGeometry Extension- serialization- versionGeometry TopologyExtension- serialization- version- relation familyQuery RewriteExtension- serialization- version- relation familyRDFS EntailmentExtension- serialization- version- relation familyParameters• Serialization• WKT• GML• Relation Family• SimpleFeatures• RCC-8• Egenhofer
  108. 108. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6GeoSPARQL CoreDefines top level classes that providesusers with vocabulary for modeling geospatialinformation. The class geo:SpatialObject is thetop class and has as instanceseverything that can have a spatialrepresentation. The class geo:Feature is a subclassof geo:SpatialObject. Feature is adomain entity that can have variousattributes that describe spatial andnon-spatial characteristics.
  109. 109. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7ExampleGeoSPARQL representation of the community ofAncient Olympia.dbpedia:Community rdfs:subClassOf geo:Feature .geonames:Olympia geonames:name "Ancient Olympia";rdf:type dbpedia:Community .
  110. 110. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data8GeoSPARQL Geometry ExtensionProvides vocabulary for asserting and queryinginformation about geometries. The class geo:Geometry is a top class which is asuperclass of all geometry classes.
  111. 111. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data9ExampleGeoSPARQL representation of the community of AncientOlympia.dbpedia:Community rdfs:subClassOf geo:Feature .geonames:Olympia geonames:name "Ancient Olympia";rdf:type dbpedia:Community .geonames:Olympia geo:hasGeometry ex:polygon1.ex:polygon1 rdf:type geo:Polygon;geo:isEmpty "false"^^xsd:boolean;geo:asWKT "POLYGON((21.5 18.5, 23.518.5, 23.5 21, 21.5 21,21.5 18.5))"^^sf:wktLiteral.Spatialdata type
  112. 112. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data10GeoSPARQL Geometry ExtensionSpatial analysis functions Construct new geometric objects from existing geometricobjectsgeof:boundary (geom1: ogc:geomLiteral): ogc:geomLiteralgeof:envelope (geom1: ogc:geomLiteral): ogc:geomLiteralgeof:intersection( geom1: ogc:geomLiteral,geom2: ogc:geomLiteral): ogc:geomLiteralgeof:union ( geom1: ogc:geomLiteral,geom2: ogc:geomLiteral): ogc:geomLiteralgeof:difference ( geom1: ogc:geomLiteral,geom2: ogc:geomLiteral): ogc:geomLiteralgeof:symDifference (geom1: ogc:geomLiteral,geom2:ogc:geomLiteral): ogc:geomLiteralgeof:buffer(geom: ogc:geomLiteral, radius: xsd:double,units: xsd:anyURI): ogc:geomLiteralgeof:convexHull(geom1: ogc:geomLiteral): ogc:geomLiteral Spatial metric functionsgeof:distance(geom1: ogc:geomLiteral, geom2:ogc:geomLiteral, units: xsd:anyURI): xsd:double
  113. 113. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data11GeoSPARQL Topology Vocabulary Extension The extension is parameterized by the family of topologicalrelations supported. Topological relations for simple features The Egenhofer relations e.g., geo:ehMeet The RCC-8 relations e.g., geo:rcc8ec
  114. 114. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Datagag:Olympiardf:type gag:Community;geonames:name "Ancient Olympia".gag:OlympiaBoroughrdf:type gag:Borough;rdfs:label "Borough ofAncient Olympia".gag:OlympiaMunicipalityrdf:type gag:Municipality;rdfs:label "Municipality ofAncient Olympia".gag:OlympiaBorough geo:sfContains geonames:Olympia .gag:OlympiaMunicipality geo:sfContainsgeonames:OlympiaBorough.12ExampleAssertedtopologicalrelation
  115. 115. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data13GeoSPARQL: An exampleSELECT ?mWHERE {?m rdf:type gag:Borough.?m geo:sfContains geonames:Olympia.}Find the borough that contains thecommunity of Ancient OlympiaTopologicalPredicate
  116. 116. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data14GeoSPARQL: An exampleSELECT ?mWHERE {?m rdf:type gag:Municipality.?m geo:sfContains geonames:Olympia.}Find the municipality that contains thecommunity of Ancient OlympiaWhat is theanswer to thisquery?
  117. 117. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data15Example (cont’d)The answer to the previous query is?m = gag:OlympiaMunicipalityGeoSPARQL does not tell you how tocompute this answer which needsreasoning about the transitivity ofrelation geo:sfContains.Options:• Use rules• Use constraint-based techniques
  118. 118. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data16GeoSPARQL Geometry Topology Extension Defines Boolean functions that correspond to each ofthe topological relations of the topology vocabularyextension: OGC Simple Features Accessgeof:sfEquals(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfDisjoint(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfIntersects(geom1: ogc:geomLiteral,geom2: ogc:geomLiteral): xsd:booleangeof:sfTouches(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfCrosses(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfWithin(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfContains(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:booleangeof:sfOverlaps(geom1: ogc:geomLiteral, geom2: ogc:geomLiteral): xsd:boolean Egenhofer RCC-8
  119. 119. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Provides a mechanism for realizing the RDFS entailments thatfollow from the geometry class hierarchies defined by the WKTand GML standards. Systems should use an implementation of RDFS entailment toallow the derivation of new triples from those already in a graph.17GeoSPARQL RDFS Entailment Extension
  120. 120. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data18ExampleGiven the triplesex:f1 geo:hasGeometry ex:g1 .geo:hasGeometry rdfs:domain geo:Feature.we can infer the following triples:ex:f1 rdf:type geo:Feature .ex:f1 rdf:type geo:SpatialObject .
  121. 121. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data19GeoSPARQL Query Rewrite Extension Provides a collection of RIF rules that use topological extensionfunctions to establish the existence of topological predicates. Example: given the RIF rule named geor:sfWithin, theserializations of the geometries of dbpedia:Athens anddbpedia:Greece named AthensWKT and GreeceWKT and thefact thatgeof:sfWithin(AthensWKT, GreeceWKT)returns true from the computation of the two geometries, we canderive the tripledbpedia:Athens geo:sfWithin dbpedia:Greece One possible implementation is to re-write a given SPARQLquery.
  122. 122. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data20RIF RuleForall ?f1 ?f2 ?g1 ?g2 ?g1Serial ?g2Serial(?f1[geo:sfWithin->?f2] :-Or(And (?f1[geo:defaultGeometry->?g1]?f2[geo:defaultGeometry->?g2]?g1[ogc:asGeomLiteral->?g1Serial]?g2[ogc:asGeomLiteral->?g2Serial]External(geo:sfWithin (?g1Serial,?g2Serial)))And (?f1[geo:defaultGeometry->?g1]?g1[ogc:asGeomLiteral->?g1Serial]?f2[ogc:asGeomLiteral->?g2Serial]External(geo:sfWithin (?g1Serial,?g2Serial)))And (?f2[geo:defaultGeometry->?g2]?f1[ogc:asGeomLiteral->?g1Serial]?g2[ogc:asGeomLiteral->?g2Serial]External(geo:sfWithin (?g1Serial,?g2Serial)))And (?f1[ogc:asGeomLiteral->?g1Serial]?f2[ogc:asGeomLiteral->?g2Serial]External(geo:sfWithin (?g1Serial,?g2Serial)))))Feature-FeatureFeature-GeometryGeometry-FeatureGeometry-Geometry
  123. 123. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21GeoSPARQL: An exampleSELECT ?featureWHERE {?feature geo:sfWithingeonames:OlympiaMunicipality.}Discover the features that are inside the municipality ofAncient Olympia
  124. 124. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data22GeoSPARQL: An exampleSELECT ?featureWHERE { {?feature geo:sfWithin geonames:Olympia }UNION{ ?feature geo:defaultGeometry ?featureGeom .?featureGeom geo:asWKT ?featureSerial .geonames:Olympia geo:defaultGeometry ?olGeom .?olGeom geo:asWKT ?olSerial .FILTER (geof:sfWithin (?featureSerial, ?olSerial)) }UNION { ?feature geo:defaultGeometry ?featureGeom .?featureGeom geo:asWKT ?featureSerial .geonames:Olympia geo:asWKT ?olSerial .FILTER (geof:sfWithin (?featureSerial, ?olSerial)) }UNION { ?feature geo:asWKT ?featureSerial .geonames:Olympia geo:defaultGeometry ?olGeom .?olGeom geo:asWKT ?olSerial .FILTER (geof:sfWithin (?featureSerial, ?olSerial)) }UNION {?feature geo:asWKT ?featureSerial .geonames:Olympia geo:asWKT ?olSerial .FILTER (geof:sfWithin (?featureSerial, ?olSerial)) }
  125. 125. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data23Conclusions Geospatial data in the Semantic Web The query language GeoSPARQL Core Topology vocabulary extension Geometry extension Geometry topology extension Query rewrite extension RDFS entailment extension Next topic: Implemented RDF Stores with GeospatialSupport
  126. 126. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography24[Perry and Herring, 2012]Open Geospatial Consortium. OGC GeoSPARQL - A geographic querylanguage for RDF data. OGC Candidate Implementation Standard(2012)
  127. 127. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataImplemented RDF Stores withGeospatial SupportPresenter: Kostis KyzirakosReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  128. 128. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataOutline Relational DBMS with a geospatial extension RDF stores with a geospatial component:• Research prototypes• Commercial systems2
  129. 129. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Geometries are not explicitly handled by query language (SQL) Define datatypes that extend the SQL type system• Model geometries using Abstract Data Type (ADT)• Hide the structure of the data type to the user The interface to an ADT is a list of operations For spatial ADTs: Operations defined according to OGCSimple Features for SQL Vendor-specific implementation irrelevant - extend SQL withgeometric functionality independently of a specificrepresentation/implementationHow does an RDBMS handlegeometries? (1/2)3
  130. 130. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSpecial indices needed for geometry data typesHow does an RDBMS handlegeometries? (2/2)4Specialised query processing methods
  131. 131. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataWill examine following aspects: Data model Query language Functionality exposed Coordinate Reference System support Indexing MechanismsImplemented Systems5
  132. 132. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Strabon Parliament Brodt et al. PerryResearch Prototypes6
  133. 133. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Storage and query evaluationmodule for stSPARQL Geometries represented using typed literalsWKT & GML serializations supported Spatial predicates represented as SPARQL functionsOGC-SFA, Egenhofer, RCC-8 families exposedSpatial aggregate functions Support for multiple coordinate reference systems GeoSPARQL supportCoreGeometry ExtensionGeometry Topology ExtensionStrabon7
  134. 134. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataStrabon - Implementation8stRDFgraphsstSPARQL/GeoSPARQLqueriesWKT GMLOpen Source, available from http://www.strabon.di.uoa.gr/
  135. 135. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Storage Engine Developed by Raytheon BBN Technologies Implementation of GeoSPARQL• Geometries represented using typed literalsWKT & GML serializations supported• Three families of topological functionsexposedOGC-SFAEgenhoferRCC-8• Multiple CRS supportParliament9
  136. 136. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Rule engine included Paired with queryprocessor R-tree usedParliament - Implementation10Open Source, available fromhttp://www.parliament.semwebcentral.org
  137. 137. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Built on top of RDF-3X Implemented at University of Stuttgart No formal definitions of data model andquery language given Geometries expressed according to OGC-SFATyped LiteralsWKT serialization supportedExpressed in WGS84 Spatial predicates represented as SPARQLfilter functionsOGC-SFA functionality exposedBrodt et al.11
  138. 138. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataFocus on spatial queryprocessing and spatialindexing techniques forspatial selectionse.g. "Retrieve featureslocated inside a givenpolygon"Naive spatial selectionoperatorPlaced in front of the executionplan which the plannerreturnsSpatial index(R-Tree) implementedOnly utilized in spatialselectionsBrodt et al. - Implementation12Available upon request
  139. 139. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Built on top of Oracle 10g Implemented at Wright State University Implementation of SPARQL-STUpper-level ontology imposed Geometries expressed according to GeoRSS GML Spatial and temporal variables introduced Spatial and temporal filters used to filter results withspatiotemporal constraintsRCC-8 calculusAllen’s interval calculusPerry13
  140. 140. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Spatiotemporal operators implemented using Oraclesextensibility framework Three spatial operators defined Strictly RDF concepts implemented using Oracle’s RDFstorage and inferencing capabilities R-Tree used for indexing spatial objectsPerry - Implementation14Available upon request
  141. 141. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data AllegroGraph OWLIM Virtuoso uSeekMCommercial RDF Stores15
  142. 142. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Well-known RDF store, developed by Franz Inc. Two-dimensional point geometriesCartesian / spherical coordinate systems supported GEO operator introduced for queryingSyntax similar to SPARQL’s GRAPH operatorAvailable operations:Radius / Haversine (Buffer)Bounding BoxDistance Linear Representation of data X and Y ordinates of a point are combined into a single datum Distribution sweeping technique used for indexing• Strip-based index Closed source, available fromhttp://www.franz.com/agraph/allegrograph/AllegroGraph16
  143. 143. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Semantic Repository, developed by Ontotext Two-dimensional point geometries supportedExpressed using W3C Geo VocabularyPoint GeometriesWGS84 Spatial predicates represented as property functionsAvailable operations:Point-in-polygonBufferDistance Implemented as a Storage and Inference Layer for Sesame Custom spatial index used Closed SourceFree version available for evaluation purposeshttp://www.ontotext.com/owlimOWLIM17
  144. 144. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Multi-model data server, developed by OpenLink Two-dimensional point geometriesTyped literalsWKT serialization supportedMultiple CRS support Spatial predicates represented as functionsSubset of SQL/MM supported R-Tree used for indexing Spatial capabilities firstly included in Virtuoso 6.1 Closed SourceOpen Source Edition available fromhttp://virtuoso.openlinksw.com/Does not include the spatial capabilities extensionVirtuoso18
  145. 145. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data Add-on library for Sesame-enabled semantic repositories,developed by OpenSahara Geometries expressed according to OGC-SFAWKT serializationOnly WGS84 supported Spatial predicates represented as functionsOGC-SFA functionality exposedAdditional functionse.g. shortestline(geometry,geometry) Implemented as a Storage and Inference Layer (SAIL) for SesameMay be used with RDF stores that have a Sesame Repository/SAIL layer R-tree-over-GiST index used (provided by PostGIS) Open Source, Apache v2 License Available from https://dev.opensahara.com/projects/useekmuSeekM19
  146. 146. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSystem Language Index Geometries CRS support Comments onFunctionalityStrabon stSPARQL/GeoSPARQL*R-tree-over-GiSTWKT / GMLsupportYes • OGC-SFA• Egenhofer• RCC-8Parliament GeoSPARQL R-Tree WKT / GMLsupportYes •OGC-SFA•Egenhofer•RCC-8Brodt et al.(RDF-3X)SPARQL R-Tree WKT support No OGC-SFAPerry SPARQL-ST R-Tree GeoRSSGMLYes RCC-8AllegroGraph ExtendedSPARQLDistributionsweepingtechnique2D pointgeometriesPartial •Buffer•Bounding Box•DistanceOWLIM ExtendedSPARQLCustom 2D pointgeometries(W3C Basic GeoVocabulary)No •Point-in-polygon•Buffer•DistanceVirtuoso SPARQL R-Tree 2D pointgeometries(in WKT)Yes SQL/MM(subset)uSeekM SPARQL R-tree-overGiSTWKT support No OGC-SFA
  147. 147. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data21Conclusions Semantic Geospatial Systems: Research Prototypes Commercial Systems Next topic: Geospatial information withdescription logics, OWL and rules
  148. 148. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography22[Kyzirakos et al, 2010]K. Kyzirakos , M. Karpathiotakis, M. Koubarakis: DevelopingRegistries for the Semantic Sensor Web using stRDF and stSPARQL(short paper). In: Proceedings of the 3rd International Workshopon Semantic Sensor Networks (SSN10) (2010)[Kyzirakos et al, 2012]K. Kyzirakos , M. Karpathiotakis, M. Koubarakis: Strabon: A SemanticGeospatial DBMS. In: Proceedings of the 11th InternationalSemantic Web Conference (2012)[Battle and Kolas, 2011]Battle, R., Kolas, D.: Enabling the Geospatial Semantic Web withParliament and GeoSPARQL (2011)
  149. 149. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography23[Brodt et al, 2010]A. Brodt, D. Nicklas, and B. Mitschang. Deep integration of spatialquery processing into native rdf triple stores. In ACM SIGSPATIAL,2010.[Perry, 2007]Matthew Perry. A Framework to Support Spatial, Temporal andThematic Analytics over Semantic Web Data. PhD thesis, WrightState University, 2008
  150. 150. Geospatial Information withDescription Logics, OWL, andRulesPresenter: Charalampos NikolaouReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  151. 151. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataOutline§  Geospatial information with description logicsand OWL§  OWL reasoners with geospatial capabilities§  Geospatial information with SWRL rules2
  152. 152. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with DLs andOWLThree main approaches:1.  Use a DL as it is2.  Define a spatial DL (concrete domain approach)3.  Hybrid: OWL + Spatial ABox3
  153. 153. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is4
  154. 154. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is5Use OWL-DL§  Regions are represented by concepts§  Points are represented by individuals§  RCC-8 relations among regions expressed by DL axiomsTranslation of PO(X, Y) asXYZ1 Z3 Z2TBoxABox
  155. 155. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataUse a DL as it is7Use OWL-DLDiscussion§  Impractical when implemented in a reasoner[Stocker-Sirin, OWLED’09]§  Unnatural modeling?§  Can we generalize the approach?§  For example, can we define the concept of a dream house as onethat is located inside a forest?§  How do we express disjunctions of RCC-8 relations (indefiniteinformation)?
  156. 156. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataDefine a spatial DL(concrete domain approach)11
  157. 157. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConcrete domains§  Reason about specific domains(real numbers, time intervals, spatial regions)§  Formalization of a concrete domain using a first-ordertheory§  From roles to features: associate an individual to avalue from a concrete domain§  Notation:12
  158. 158. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConcrete domainsExamples:§  Reals with order ( )Domain: the set of real numbersPredicates: < interpreted by the “less-than” relation§  Allen’s Interval CalculusDomain: the set of time intervalsPredicates: Allen’s basic interval relations (before, starts, etc.)and Boolean combinations of them§  RCC-8 CalculusDomain: the set of non-empty, regular closed subsets ofPredicates: basic RCC-8 relations (EQ, PO, etc.) and Booleancombinations of them13
  159. 159. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTBoxConcept equivalences/inclusions can include features andconcrete domain predicatesABoxAssertions can associate an individual to values from aconcrete domain14Concrete domains
  160. 160. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTwo state of the art approaches§  : with RCC-8 calculus as the concrete domain§  extension of model-theoretic semantics of§  ω-admissibility property§  tableau-based technique15Concrete domains
  161. 161. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataTwo state of the art approaches§  : with RCC-8 calculus as the concrete domain§  extension of model-theoretic semantics of§  ω-admissibility property§  tableau-based technique§  : DL-Lite with RCC-8 calculus as the concretedomain§  extension of model-theoretic semantics of DL-Lite§  FOL-rewritability for unions of conjunctive queries16Concrete domains
  162. 162. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne that is located inside a pine forest and borders a lake17
  163. 163. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne that is located inside a pine forest and borders a lake18
  164. 164. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne that is located inside a pine forest and borders a lake19
  165. 165. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne that is located inside a pine forest and borders a lake20
  166. 166. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example§  DreamHouseOne that is located inside a pine forest and borders a lake21
  167. 167. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox22
  168. 168. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox§  Question: Is individual h a DreamHouse?23
  169. 169. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox§  Question: Is individual h a DreamHouse?§  Answer: Yes.24
  170. 170. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox§  Question: Is individual h a DreamHouse?§  Answer: Yes.§  Why?25☐☐
  171. 171. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox26☐☐
  172. 172. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox27☐☐
  173. 173. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox28☐☐
  174. 174. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataAn Example (classification)§  ABox29☐☐
  175. 175. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox30
  176. 176. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox31General architectureKBTBox ABoxDLDL Reasoning
  177. 177. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox32General architectureKBTBox ABoxDLDL Reasoning
  178. 178. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox33General architectureKBTBox ABoxDLDL ReasoningSpatialABoxSpatial Reasoning
  179. 179. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox341. Grutter et al.2. Reasoner RacerPro (DL/OWL + Spatial ABox)3. Reasoner PelletSpatial (DL/OWL + Spatial ABox)
  180. 180. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox35Domain Knowledge (TBox)§  Introduction of roles (e.g., partiallyOverlaps) for RCC relations(e.g., PO)§  spatiallyRelated: top role for topological relations§  Role inclusion axioms for RCC relationsAssertions (ABox)§  Assertion of the “connectsWith” relation, connectsWith(a, b),between two regions (individuals)[Grütter et al., ISWC‘08]
  181. 181. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox36RCCBox§  Definition of RCC relations based on the “connectsWith” relation§  Axioms for composition tables of RCCPredicate C(x, y)corresponds to roleconnectsWith(x, y) in ABox[Grütter et al., ISWC‘08]
  182. 182. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataHybrid: OWL + Spatial ABox38Application1.  Input: a set of geometries (polygons in )2.  Compute assertions of the form connectsWith(a, b)3.  Update ABox with new spatial relations according to definitions in RCCBox1.  Should DC(a, b) be inferred in RCCBox, then2.  the role assertion disconnectedWith(a, b) is inserted in ABox4.  Check spatial consistency of ABox using path consistency on the RCC networkconstructed from the spatial role assertions of the ABox[Grütter et al., ISWC‘08]
  183. 183. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataThe reasoner RacerPro39§  Description Logic:§  Spatial Extension: the ABox is associated to a spatialrepresentation layer (RCC substrate)§  RCC substrate: offers representation and querying facilities forRCC networksFeatures§  Representation of indefinite information: disjunctions of RCCrelations can be used between two individuals§  Consistency checking of RCC networks§  Querying of asserted and entailed RCC relations using the querylanguage nRQL[Möller et al.][Wessel-Möller, JAPLL’09]Available fromhttp://www.racer-systems.com/products/racerpro/
  184. 184. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data40§  Spatial regions: a, b, and c§  Region a contains b(rcc-related a b ((:ntppi :tppi)))§  Region a is disjoint with c(rcc-related a c (:dc))bXacbXaRacerPro: ABox Reasoning
  185. 185. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data41§  Spatial regions: a, b, and c§  Region a contains b(rcc-related a b ((:ntppi :tppi)))§  Region a is disjoint with c(rcc-related a c (:dc))(?) Which regions are disjoint?bXacbXaRacerPro: ABox Reasoning
  186. 186. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data42§  Spatial regions: a, b, and c§  Region a contains b(rcc-related a b ((:ntppi :tppi)))§  Region a is disjoint with c(rcc-related a c (:dc))?(retrieve (?x ?y) (and (?x ?y :dc)))bXacbXaRacerPro: ABox Reasoning
  187. 187. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataRacerPro: ABox Reasoning43§  Spatial regions: a, b, and c§  Region a contains b(rcc-related a b ((:ntppi :tppi)))§  Region a is disjoint with c(rcc-related a c (:dc))?(retrieve (?x ?y) (and (?x ?y :dc)))(a, c) and (c, b)bXacbXa
  188. 188. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataDream House (definition)§  DreamHouseOne that is located inside a pine forest and borders a lake44
  189. 189. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  DreamHouseOne that is located inside a pine forest and borders a lake45(implies DreamHouse(and(all hasForest PineForest)(all hasLake Lake)))Dream House (definition)
  190. 190. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  DreamHouseOne that is located inside a pine forest and borders a lake46(implies DreamHouse(and(all hasForest PineForest)(all hasLake Lake)))?Dream House (definition)
  191. 191. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox47Dream House (ABox reasoning)
  192. 192. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are the houses that are threatened?48Dream House (ABox reasoning)
  193. 193. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are the houses that are threatened?§  Answer: House h.49Dream House (ABox reasoning)
  194. 194. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data§  ABox§  Question: What are the houses that are threatened?§  Answer: House h.§  Why?50Dream House (ABox reasoning)
  195. 195. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data51Dream House (ABox reasoning)
  196. 196. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data52NTPPDream House (ABox reasoning)
  197. 197. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data53NTPPECDream House (ABox reasoning)
  198. 198. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data54NTPPNTPPECDream House (ABox reasoning)
  199. 199. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data55NTPPECComposition of edge(vh, vn) and (vn, vf)NTPPDream House (ABox reasoning)
  200. 200. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data56NTPPECComposition of edge(vh, vn) and (vn, vf)NTPPDream House (ABox reasoning)
  201. 201. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data57NTPPPO, TPP, NTPPECNTPPDream House (ABox reasoning)
  202. 202. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data58NTPPPO, TPP, NTPPECNTPPDream House (ABox reasoning)
  203. 203. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataThe reasoner PelletSpatial59§  Description Logic: OWL 2 ( )§  Spatial Extension: Separate ABox for spatial data§  Spatial ABox: Topological relations are managed as a basicRCC-8 network (a single relation between two nodes)Features§  Representation of definite information only§  Consistency checking of basic RCC-8 networks (path consistency)§  Querying of asserted and entailed basic RCC-8 relations using asubset of SPARQL (BGPs and operator AND)[Stocker-Sirin, OWLED‘09]Available fromhttp://clarkparsia.com/pellet/spatial
  204. 204. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataSWRL Rules60
  205. 205. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules61Extension of OWL for the representation of qualitative andquantitative spatial information (SOWL)§  RCC-8§  Directional relations (e.g., East, North-West), and§  Distance relations (e.g., “3Km away from Vienna”)[Batsakis et al., RuleML’11]
  206. 206. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataModelingGeospatial information with SWRLrules62FootprintPolyline MBRLinePointX Y XminYminXmaxYmaxReg2DistanceReg1-Reg2Reg13LocationWestOfclassinstancedatatypesubclasspropertyLegend[Batsakis et al., RuleML’11]
  207. 207. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules63Spatial assertions§  RCC-8 relations between two regions§  Directional relations between two regions§  Distance relations between two regions§  Geometry of regions (in subclasses of Footprint)[Batsakis et al., RuleML’11]
  208. 208. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules64Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations[Batsakis et al., RuleML’11]
  209. 209. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules65Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)[Batsakis et al., RuleML’11]
  210. 210. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules66Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)[Batsakis et al., RuleML’11]
  211. 211. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules67Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)denotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  212. 212. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules68Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)denotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  213. 213. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules69Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)denotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  214. 214. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules70Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)Current relation between regions x and ydenotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  215. 215. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules71Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)Composition of Rj with RkCurrent relation between regions x and ydenotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  216. 216. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules72Implementation of the previous framework using OWL1. OWL 2 property axioms for expressing inverse, symmetry, and transitivityfor spatial relations2. SWRL rules to§  encode composition of spatial relations§  compute the intersection of two sets of spatial relations§  check spatial consistency (using Pellet)Composition of Rj with RkCurrent relation between regions x and yNew relation between x and ydenotes disjunction ofrelations DC and EC[Batsakis et al., RuleML’11]
  217. 217. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataGeospatial information with SWRLrules73§  Implementation of SOWL is available athttp://www.intelligence.tuc.gr/prototypes.php[Batsakis et al., RuleML’11]
  218. 218. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataConclusions75§  We talked about§  Geospatial information with description logics andOWL§  OWL reasoners with geospatial capabilities§  Geospatial information with SWRL rules§  Next topic: conclusions, questions, discussion
  219. 219. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography76[Katz et al., OWLED’05]Yarden Katz, Bernardo Cuenca Grau: Representing Qualitative SpatialInformation in OWL-DL. OWLED 2005[Lutz-Milicic, JAR‘07]Carsten Lutz, Maja Milicic: A Tableau Algorithm for Description Logicswith Concrete Domains and General TBoxes. J. Autom. Reasoning(JAR) 38(1-3):227-259 (2007)[Özçep-Möller, DL‘12]Özgür L. Özçep, Ralf Möller: Combining DL-Lite with Spatial Calculifor Feasible Geo-thematic Query Answering. Description Logics 2012[Grütter et al., ISWC‘08]Rolf Grütter, Thomas Scharrenbach, Bettina Bauer-Messmer:Improving an RCC-Derived Geospatial Approximation by OWLAxioms. International Semantic Web Conference 2008:293-306
  220. 220. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial DataBibliography77[Wessel-Möller, JAPLL’09]Michael Wessel, Ralf Möller: Flexible software architectures forontology-based information systems. J. Applied Logic (JAPLL) 7(1):75-99 (2009)[Stocker-Sirin, OWLED‘09]Markus Stocker, Evren Sirin: PelletSpatial: A Hybrid RCC-8 and RDF/OWL Reasoning and Query Engine. OWLED 2009[Batsakis-Petrakis, RuleML’11]Sotiris Batsakis, Euripides G. M. Petrakis: SOWL: A Framework forHandling Spatio-temporal Information in OWL 2.0. RuleML Europe2011:242-249
  221. 221. ConclusionsPresenter: Manolis KoubarakisReasoning Web 2012Dept. of Informatics and TelecommunicationsNational and Kapodistrian University of AthensSummer School
  222. 222. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data2What we talked about Introduction Background in geospatial data modeling Geospatial data in the Semantic Web(extensions to RDF, stSPARQL andGeoSPARQL, spatial DLs, rules) Implemented systems (RDF stores,spatial DL reasoners, rule-based)
  223. 223. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data3What we did not talk about: Tools• Tools for translating GIS data (e.g.,shape files or tables from a geospatialDBMS) into the geospatial extensions ofRDF that we presented.
  224. 224. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data4What we did not talk about:Representational issues• What are appropriate vocabularies andontologies for representing geospatialinformation? (GeoSPARQL only)• Is the GeoSPARQL vocabularies/ontologiesalways appropriate?• Is using the WKT/GML encoding of a spatialobject always a good idea?
  225. 225. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data5What we did not talk about: Theory• Semantics: How do we extend the semanticsof SPARQL, to give semantics to stSPARQL andGeoSPARQL?• Computational complexity of queryprocessing: What is the complexity ofstSPARQL or GeoSPARQL querying?• Same questions for DLs, OWL and rules.
  226. 226. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data6Some open research questions• More efficient geospatial RDF stores (can you beatStrabon?)• Federations of geospatial RDF stores• More expressive/efficient spatial DL reasoners• Theory (extensions of SPARQL, extensions of DLs,extensions of SWRL)• OWL 2 and geospatial (e.g., new data types)• More efficient SWRL+spatial implementations
  227. 227. Reasoning Web 2012 – Summer SchoolData Models and Query Languages for Linked Geospatial Data7Thank you for Attending!• Questions?• Feedback?

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