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Yang Ou School of GeoSciences The University of Edinburgh Expressing the Semantics of Geographic Information and Processes.

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Presentation on theme: "Yang Ou School of GeoSciences The University of Edinburgh Expressing the Semantics of Geographic Information and Processes."— Presentation transcript:

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2 Yang Ou School of GeoSciences The University of Edinburgh Expressing the Semantics of Geographic Information and Processes

3 Syntactic Semantic data conversion Spatial Data Transfer Standard (SDTS) Open Geodata Interoperability Specification (OGIS) Web Services Ontologies InformationProcessesInteroperability Approaches to Achieve GIS Interoperability

4 Describing the Semantics of Geographic Information

5 Model 1 Model 2Model 3Model n … Ontology conceptual level data level

6 Real-world Entities Spatial Database represents geometryidname … … geometryid Schemas/Data model Domain Ontology conceptualises models implements Relationship between Representations of Spatial Information

7 Real-world Entities Spatial Database represents geometryidname … … geometryid Schemas/Data model conceptualises models implements Domain OntologyData Ontology conceptualises hasLocation hasConcept

8 SpatialDataset RasterDataset PointDatasetPolygonDataset VectorDataset LineDataset subClassOf hasLocationhasConcept Literal domain range Basic Conceptualisation of Spatial Dataset in RDFS VectorDataset ≡ SpatialDataset u = 1hasGeometry PointDataset ≡ VectorDataset u 8 hasGeometry.Point LineDataset ≡ VectorDataset u 8 hasGeometry.Line PolygonDataset ≡ VectorDataset u 8 hasGeometry.Polygon RasterDataset ≡ SpatialDataset u : VectorDataset u = 1hasResolution SpatialDataset ≡ Dataset u = 1hasCoordinateSystem Part of the Definition of the Data Ontology

9 To utilise the “semantic information”, we need “semantic processes”.

10 Constructing Semantic Web Services for Geospatial Processes

11 Point {double x; double y} Example: there was a Web service that was providing a process to calculate the distance between two points. double distanceBetween(Point a, Point b);

12 Geospatial Process spatial data SOAP message ontological instance Web Service Semantic Web Service Semantic Interface Syntactic Interface Interoperability Structure for Geospatial Processes

13 Syntactic Interface Semantic Interface data Atomic Process Input handler instance dataset describes fetch data Input Handling Process

14 describes Syntactic Interface Semantic Interface creates data Atomic Process Output handler instance dataset instance stores Output Handling Process

15 Atomic Geospatial Process Input Handling Process Output Handling Process spatial data instance spatial data Atomic Geospatial Processing Unit

16 A Running Example Identifying a certain kind of facility near given locations Process 1: Creating buffer areas of the given locations break down into two steps Process 2: Selecting the features that drop within the buffer areas

17 The Processing Unit of the Buffering Process

18 The Processing Unit of the Selection Process

19 Combination of the Two Processing Units

20 Randomly Produced Layers for Testing

21 Virtual Data Source

22 Describing the Datasets in an Ontology

23 choose the layer to be selected choose the layer to be buffered specify the buffer distance Output: the URI of the instance that describes the process result

24 explore the output URI

25 retrieve the spatial data of the process result through the location property in the ontology

26 Visualisation of the Output Data Sets

27 geometry id name currency population Iceland Krona Iceland 100 polygon geometryfeature_idcountry_namecurrencypopulation POLYGON100IcelandKrona record individual A Further Idea to Apply Ontologies in GIS Representing Geographic Information as Geographic Knowledge Database vs. Knowledge base

28 hasName hasValue hasName hasValue hasAttribute hasGeometry geometryfeature_idcountry_namecurrencypopulation POLYGON100IcelandKrona Iceland polygon attribute integerid 100Iceland namestring Krona currency string double population attribute record individual

29 Some potential advantages: The process of such a kind of semantic geographic information doesn’t require communicating ontologies with spatial data. Reasoning capability of ontologies can be considered to perform potential geospatial analyses. Developing Geographic Information Systems towards Geographic Knowledge Systems.

30 Thank you!


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