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The ICAN CSW Mediator

The ICAN CSW Mediator. Yassine Lassoued y.lassoued@ucc.ie. Omar Boucelma omar.boucelma@lsis.org. Dawn Wright dawn@dusk.geo.orst.edu. Luis Bermudez bermudez@sura.org. Outline. Outline Introduction ICAN Problem Terminology Idea Approach Architecture Ontologies Mappings

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The ICAN CSW Mediator

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  1. The ICAN CSW Mediator Yassine Lassoued y.lassoued@ucc.ie Omar Boucelma omar.boucelma@lsis.org Dawn Wright dawn@dusk.geo.orst.edu Luis Bermudez bermudez@sura.org

  2. Outline • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Ontologies Mappings • Query Rewriting • Demonstration • Conclusion • Future Work JIGOT’08 – Marseille

  3. Introduction • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Demonstrate how ontologies and standards can be used to: • Help geographic information systems interoperate • Improve data discovery • Facilitate resources sharing JIGOT’08 – Marseille

  4. ICAN • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • International Coastal Atlas Network • Network of scientists, organisations and institutions with interest in the coastal and marine domain • Objective • Build and strengthen atlas networks • Develop an internationally-enabled coastal Web atlas (CWA) JIGOT’08 – Marseille

  5. ICAN • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • More than 30 members from more than 12 countries: • Coastal and Marine Resources Centre • Oregon State University • European Environmental Agency • Marine Metadata Interoperability • International Oceanographic Data and Information Exchange • Marine Institute • Etc. JIGOT’08 – Marseille

  6. Problem • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Interoperability of distributed autonomous and heterogeneous coastal Web atlases (CWA) … JIGOT’08 – Marseille

  7. Problem • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Coastal Web Atlas (CWA): • Web application for the delivery of coastal resources such as: • Geographic datasets • Maps • Metadata • Thematic (educational) information JIGOT’08 – Marseille

  8. Problem • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Heterogeneity: • Syntactic (data formats, query languages) • Structural (data schemas) • Semantic (meaning of data values)  E.g.:  Metadata: • Different metadata standards (ISO vs. FGDC) • Different terms: ‘Seabed’ vs. ‘Seafloor’ ‘Coastline’ vs. ‘Shoreline’ JIGOT’08 – Marseille

  9. Terminology • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • OGC Web Service: • OGC specification • Interface allowing requests for geographic “resources” across the Web using platform-independent calls • Main OGC services: • Catalogue Service for the Web (CSW) • Web Feature Service (WFS) • Web Coverage Service (WCS) • Web Map Service (WMS) JIGOT’08 – Marseille

  10. Terminology • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • OGC Web Service: • Catalogue Service for the Web (CSW) • Allows requests for metadata across the Web • E.g. GeoNetwork is a CSW implementation JIGOT’08 – Marseille

  11. Terminology • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Ontologies: • A Knowledge Organisation System (KOS) • Define concepts (classes and objects) • Define relationships between concepts • Define inference rules • Examples: • John is a Person • Mary is a Person • Mary is mother of John • If (X is father of Y & Y is father of Z) then X is grand-father of Z JIGOT’08 – Marseille

  12. Same data structure Same semantics Query Response Mediator Same query language Same data model and format Wrapper Wrapper Wrapper Oracle DB Access DB Text Heterogeneous data sources Terminology • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Mediation: • A virtual data integration approach • Allows transparent access and integration of autonomousdistributedheterogeneous data sources JIGOT’08 – Marseille

  13. Global atlas Local atlases Idea • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Connect individual coastal atlases to an integrated global atlas … JIGOT’08 – Marseille

  14. Approach • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Centralised system  Resources are accessed through one central system (ICAN global atlas) • Virtual integration approach  Data are not copied into the global Atlas • Local atlases autonomy  Each data atlas is autonomous and organises resources in its own way and uses its own terminology (ontology) JIGOT’08 – Marseille

  15. Approach • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • To achieve interoperability: • Harmonisation: • Harmonise access interfaces and resource formats • Implement OGC Web Services • Catalogue Service for the Web (CSW) • Web Feature Service (WFS) • Web Coverage Service (WCS) • Web Map Service (WMS) • Use ISO metadata standards • ISO-19115 & ISO-19139  Harmonise Web querying and delivery formats JIGOT’08 – Marseille

  16. Approach • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • To achieve interoperability: • Mediation: • Allow local atlases to use their own data structures, semantics and vocabularies (ontologies) • Use a common data structure and a common ontology for the global atlas • Provide mappings (translations) between local ontologies and the global ontology JIGOT’08 – Marseille

  17. Mediation Mediation Harmonisation Harmonisation Approach • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work Harmonisation vs. Mediation ICAN Mediation Mediation Harmonisation Harmonisation JIGOT’08 – Marseille

  18. Approach • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • We focus on Metadata interoperability “Seabed” “Seafloor” Atlas X ISO Metadata & MIDA terminology FGDC Metadata & OCA terminology X Standard & X terminology … JIGOT’08 – Marseille

  19. ICAN Ontology Inference Engine Mappings MIDA Ontology OCA Ontology X Ontology Architecture • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work Mapping Example: ICAN:Coastline is similar to OCA:Shoreline Virtual CSW CSW CSW CSW X … JIGOT’08 – Marseille

  20. Local and Global Ontologies • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • A global ontology represents the keywords used in the virtual ICAN catalogue service • For each atlas X, a local ontology represents the keywords used by the X catalogue service • Five types of keywords (ISO-19115): Theme, Discipline, Place, Temporal, Stratum JIGOT’08 – Marseille

  21. Local and Global Ontologies • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work Local Ontology (OCA) Global Ontology JIGOT’08 – Marseille

  22. Ontology Mappings • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work JIGOT’08 – Marseille

  23. Ontology Mappings • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work MIDA Mappings OCA Mappings Each mappings file is an OWL ontology JIGOT’08 – Marseille

  24. Query Rewriting • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Rewrite user’s request into requests supported by local CSWs JIGOT’08 – Marseille

  25. Query Rewriting • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work http://ican.ucc.ie/srv/en/csw?request=GetRecords&service=CSW&version=2.0.1 &resultType=results&namespace=csw:http://www.opengis.net/cat/csw&maxRecords=1000 &elementSetName=summary &constraint= <?xml version="1.0" encoding="UTF-8"?> <Filter xmlns=http://www.opengis.net/ogc xmlns:gml=http://www.opengis.net/gml xmlns:csw="http://www.opengis.net/cat/csw/2.0.2"> <And> <PropertyIsLike wildCard="%“ singleChar="_" escape="\"> <PropertyName>keyword</PropertyName> <Literal>HumanResponsesToCoastalChange%</Literal> </PropertyIsLike> <BBOX> <PropertyName>/csw:Record/ows:BoundingBox</PropertyName> <gml:Envelope srsName="http://www.opengis.net/gml/srs/epsg.xml#4326"> <gml:lowerCorner>-180 -90</gml:lowerCorner> <gml:upperCorner>180 90</gml:upperCorner> </gml:Envelope> </BBOX> </And> </Filter> &constraintLanguage=FILTER &constraint_language_version=1.1.0 JIGOT’08 – Marseille

  26. Query Rewriting • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work http://ican.ucc.ie/srv/en/csw?request=GetRecords&service=CSW&version=2.0.1 &resultType=results&namespace=csw:http://www.opengis.net/cat/csw&maxRecords=1000 &elementSetName=summary &constraint= <?xml version="1.0" encoding="UTF-8"?> <Filter xmlns=http://www.opengis.net/ogc xmlns:gml=http://www.opengis.net/gml xmlns:csw="http://www.opengis.net/cat/csw/2.0.2"> <And> <PropertyIsLike wildCard="%“ singleChar="_" escape="\"> <PropertyName>keyword</PropertyName> <Literal>HumanResponsesToCoastalChange%</Literal> </PropertyIsLike> <BBOX> <PropertyName>/csw:Record/ows:BoundingBox</PropertyName> <gml:Envelope srsName="http://www.opengis.net/gml/srs/epsg.xml#4326"> <gml:lowerCorner>-180 -90</gml:lowerCorner> <gml:upperCorner>180 90</gml:upperCorner> </gml:Envelope> </BBOX> </And> </Filter> &constraintLanguage=FILTER &constraint_language_version=1.1.0 JIGOT’08 – Marseille

  27. Query Rewriting • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work Mediator uses inference engine to translate global terms into local terms MIDA Mappings OCA Mappings JIGOT’08 – Marseille

  28. Query Rewriting • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work <PropertyIsLike wildCard="%“ singleChar="_" escape="\"> <PropertyName>keyword</PropertyName> <Literal>HumanResponsesToCoastalChange%</Literal> </PropertyIsLike> Global MIDA <Or> <PropertyIsLike wildCard="%“ singleChar="_" escape="\"> <PropertyName>keyword</PropertyName> <Literal>CoastalProtection%</Literal> </PropertyIsLike> <PropertyIsLike wildCard="%“ singleChar="_" escape="\"> <PropertyName>keyword</PropertyName> <Literal>CoastalDefenceStructure%</Literal> </PropertyIsLike> </Or> JIGOT’08 – Marseille

  29. Demonstration • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work http://ican.ucc.ie JIGOT’08 – Marseille

  30. Conclusion • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Efficient solution for facilitating syntactic, structural and semantic interoperability • A system that can be integrated as a node within another mediated system • Ontologies and standards facilitate interoperability • This is a first step in atlases interoperability focusing only on metadata and catalogue services JIGOT’08 – Marseille

  31. Future Work • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work • Include Web Map Service (WMS) for data visualisation • Include Web Feature Service (WFS) & Web Coverage Service (WCS) for actual data delivery • Share resources (thematic information about layer) JIGOT’08 – Marseille

  32. ICAN Ontology Mappings MIDA Ontology OCA Ontology X Ontology Future Work • Outline • Introduction • ICAN • Problem • Terminology • Idea • Approach • Architecture • Ontologies • Mappings • Query Rewriting • Demonstration • Conclusion • Future Work Mapping Example: ICAN:Coastline is similar to OCA:Shoreline CSW WMS WFS CSW WMS WFS CSW WMS WFS X … JIGOT’08 – Marseille

  33. Thank You

  34. Terminology • OGC Web Service: • Web Feature Service (WFS)  Vector data • Allows requests for geographic features across the Web • E.g. GeoServer, Deegree are WFS implementations JIGOT’08 – Marseille

  35. Terminology • OGC Web Service: • Web Coverage Service (WCS)  Raster data • Allows requests for grid data across the Web • E.g. GeoServer, Deegree implement WCS JIGOT’08 – Marseille

  36. Terminology • OGC Web Service: • Web Map Service (WMS)  Maps • Allows requests for maps across the Web • E.g. UMN MapServer is a WMS JIGOT’08 – Marseille

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