Semantic integration of authoritative and VGI
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This document discusses integrating authoritative and volunteered geographic information using an ontological approach. It presents the problems caused by semantic heterogeneity between different data sources. The proposed approach uses a domain ontology and R2RML mappings to provide a common conceptualization and allow flexible integration of datasets in RDF. Current work is analyzing semantic heterogeneity in OpenStreetMap tags by studying how tags used for real-world features vary over spatial scale and time. Future work includes developing the ontology further and creating a user interface for the R2RML mappings.
![INTEGRATING AUTHORITATIVE
AND VOLUNTEERED
GEOGRAPHIC INFORMATION -
AN ONTOLOGICAL APPROACH
Crowd Sourcingin
NationalMapping
InternshipFunding
ACTIVITYWorkshop
Leuven(Belgium)
14thMay2013
JimenaMartínezRamos
[jmr125@mun.ca]](https://image.slidesharecdn.com/semanticintegrationofofficialandvgijmr-130516012122-phpapp01/85/Semantic-integration-of-authoritative-and-VGI-1-320.jpg)
![Thank you. Gracias.
Questions?
12
AGILE/EuroSDR
NSERC
TUDelft
IGNSpain
SinfogeoLtd.
Dr.JeanBrodeur
Drs.MariandeVries
MarineandGeomaticsLabcolleagues
<amenity=plane>
Acknowledgements
PNOA aerial images. IGN Spain Icons by http://dryicons.com Jimena Martinez [jmr125@mun.ca]](https://image.slidesharecdn.com/semanticintegrationofofficialandvgijmr-130516012122-phpapp01/85/Semantic-integration-of-authoritative-and-VGI-12-320.jpg)
Semantic integration of authoritative and VGI
- 1. INTEGRATING AUTHORITATIVE AND VOLUNTEERED GEOGRAPHIC INFORMATION - AN ONTOLOGICAL APPROACH Crowd Sourcingin NationalMapping InternshipFunding ACTIVITYWorkshop Leuven(Belgium) 14thMay2013 JimenaMartínezRamos [jmr125@mun.ca]
- 2. Table of contents 2 1. Background 2. Problem 3. Objective 4. Proposed approach 5. Semantics in OSM datasets (ongoing work) 6. Conclusions and future work
- 3. Background 3 (*) http://ggim.un.org/ (UN Report, 2012) National Mapping Agencies (NMAs) are likely to find difficult to justify the costs of traditional data maintenance mechanisms. VGI projects (like OpenStreetMap) are growing and are seen as a good data source to be integrated with authoritative datasets. There is growing need of integrating different data sources. Semantic interoperability is still an issue in the integration problem. TheneedofintegratingGeographicInformationfromdifferentsources ? Levels of heterogeneity System Syntactic Structural Semantic (meaning of words)
- 4. The Problem 4 SemanticHeterogeneityinGeographicInformation motorway Conceptualization turnpike trunk Conceptualization Words or symbols stand for things through ideas Different conceptualizations: Semantic Heterogeneities Ogden and Richards, 1923 Conceptualization Conceptualization Reality (road)Symbol (freeway)
- 5. trunk Conceptualization The Problem 5 SemanticHeterogeneityinGeographicInformation turnpike Pre-process Everybody thinking the same Post-process Matching symbols with the same meaning STANDARDS!ONTOLOGIES! Reality (road) Conceptualization freewayfreeway Conceptualization Conceptualization trunk Conceptualization ConceptualizationConceptualization
- 6. 6 ObjectSubject Road Transpor tation “Explicit specification of a conceptualization” Gruber, 1993 They are ways to conceptualize a domain. The Problem Whatareontologiesabout? Class Properties (Sub)class isSubclassOf Predicate isSuperclassOf
- 8. motorway trunk freeway Official source 1 turnpike Proposed Approach 8 Themethodaccordingtheobjectives “turnpike” R2RML mapping R2RML mapping R2RML mapping RDF RDF RDF Standard Domain Ontology Reality Common Knowledge “motorway” Official source 1 OpenStreetMap
- 9. Quebec • <highway=bus_stop> St. John´s ▪ <public_transport=stop_position> 9 Morethanonetagperreal-worldphenomenon (synonymy) Ongoingwork:SemanticHeterogeneityin OSM datasets ▪▪▪ ▪▪▪ ▪ ▪ Number of tags per phenomenon increases with the scale, and % is important •<highway=bus_stop> ▪<public_transport=stop_position>
- 10. 10 Morethanonetagperreal-worldphenomenon (synonymy) Ongoingwork:SemanticHeterogeneityin OSM datasets Number of tags per phenomenon evolve with time, and % is still important •<highway=bus_stop> ▪<public_transport=stop_position> 2006 2008 Agreement through timeIncreasing level of agreementDecreasing level of agreement
- 11. Conclusions and future work 11 Proposed approach is based in a domain ontology, which allows: • Matching datasets to a common pivot (R2RML allows flexible and direct mappings) • No need to know how to handle ontologies. • Reusing the mappings. Semantic Heterogeneity in OSM datasets. • Number of tags and their % of occurrence per real-world phenomenon • Time and spatial scale are factors affecting SH in OSM datasets. Future work: • Developing more the ontology. • User-friendly interface for making R2RML mappings. • Deeper study factors involved in SH in OSM datasets, trying to model it.
- 12. Thank you. Gracias. Questions? 12 AGILE/EuroSDR NSERC TUDelft IGNSpain SinfogeoLtd. Dr.JeanBrodeur Drs.MariandeVries MarineandGeomaticsLabcolleagues <amenity=plane> Acknowledgements PNOA aerial images. IGN Spain Icons by http://dryicons.com Jimena Martinez [jmr125@mun.ca]