DG Joint Research Center

13th of March 2014

Study and guidelines on Geospatial Linked Data as part of ISA Action 1.17 Resource Description Framework

Danny Vandenbroucke

Diederik Tirry

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Agenda

Introduction

Context

3

2

2

Literature study results

4

5

Sharing your experience – Issues/Challenges?

1

Next steps - Experiments

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Introduction

3

We will provide an outline of the study and our work so far. This webinar is also an opportunity to provide feedback and to exchange experiences: where could INSPIRE RDF be used in e-government?

METHODOLOGIES

WEBINAR II Guidelines on

methodologies Presentation of the first version of the guidelines for a common RDF Vocabulary for INSPIRE data and an approach to PID governance: opportunities for community-led improvements and next steps towards an official INSPIRE encoding.

Today’s webinar

1. Setting the scene

2. Developing proposals

3. Refinement & recommendations

Resource Description Framework

(RDF)

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Agenda

Introduction

Context

3

2

4

Literature study results

4

5

Sharing your experience – Issues/Challenges?

1

Next steps - Experiments

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Context

5

This study has been prepared in the context of

the Interoperability for European Public

Administrations (ISA) Programme and, in

particular A Reusable INSPIRE Reference

Platform (ARE3NA, ISA Action 1.17)

Connecting Geospatial Data This study should provide:

1. Shared evidence about the current status

in Europe of linked (geospatial) data

related to INSPIRE.

2. An initial common/agreed methodology

and guidelines towards RDF encodings for

INSPIRE

3. Recommendations for how location PIDs

could be governed for INSPIRE and other

relevant activities.

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Context

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INSPIRE Interoperability of geospatial data sets and services through harmonised data models and encodings for the exchange of data related to one of the 34 spatial data themes

1. Data models using UML at conceptual level 2. Encoding using GML based on encoding rules

Several European project and national initiatives using publishing geospatial data as Linked Data

Using the Resource Description Framework (RDF)

However No agreed rules or guidelines on how to create

such RDF vocabularies from the UML models

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Agenda

Introduction

Context

3

2

7

Literature study results

4

5

Sharing your experience – Issues/Challenges?

1

Next steps - Experiments

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Current State and State of the Art

8

Literature selection and review approach

Compile and examine relevant, existing studies • External publications from presentations, technical reports, papers and books (see list)

Describe different projects/initiatives at the European, national and sub-national

levels, in the form of an overview table, including the approach followed • Most of the literature is related to (pilot) projects that took/are taking place in some

Member States, among others The Netherlands, UK, Germany, Spain, Italy and Belgium or

in European projects such as GeoKnow

A selection of different projects/initiatives will be analyzed in more detail based

upon agreed criteria • The focus for this part of the analysis will be on the technical aspects of the

transformation of UML models into RDF

The literature analysis is currently ongoing • The literature overview for RDF/UML is presented in the table below

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Literature study results

9

Author(s) Date Title Type Description

Folmer, E., Reuvers, M., & Wilko, Q.

2013 Pilot Linked Open Data Nederland (NL) B

Source: http://www.pilod.nl/doc/boek2.pdf

Hart, G., & Dolbear, C. 2013 Linked Data: a Geographic Perspective B Source: Boca Raton: CRC Press, Taylor & Francis Group

Heath, T., Hausenblas, M., Bizer, C., Cyganiak, R., & Hartig, O.

2008

How to Publish Linked Data on the Web W

Source: http://events.linkeddata.org/iswc2008tutorial/

Jentzsch, A. 2011 LOD Cloud Diagram as of September 2011 W Source:

http://en.wikipedia.org/wiki/File:LOD_Cloud_Diagram_as_of_September_2011.png

W3C 2013 Linking Open Data - W3C SWEO Community Project. W Source:

http://www.w3.org/wiki/SweoIG/TaskForces/CommunityProjects/LinkingOpenData

Folmer, E. 2013 Introductie tweede Linked Open Data Pilot PPT Source:

http://www.geonovum.nl/sites/default/files/Presentatie%200%20ErwinFolmerv4.pdf

Farazi, F. et al. 2012

Trentino government linked open geodata: first results

PPT Source: http://inspire.jrc.ec.europa.eu/events/conferences/inspire_2012/presentations/14.pdf

Lopez-Pellicer, F.J., Florczyk, A.J., Nogueras-Iso, J., Muro-Medrano, P.R. & Zarazaga-Soria, F.J.

2011

Linked Open Data for INSPIRE: From 3 to 5 star geospatial data

PPT Source: http://inspire.jrc.ec.europa.eu/events/conferences/inspire_2011/presentations/170.pdf

Schade, S. & Lutz, M. 2010 Opportunities and Challenges for using Linked Data in INSPIRE

P Source: http://publications.jrc.ec.europa.eu/repository/handle/111111111/15247

Tschirner, S., Scherp, A. & Staab, S.

2011 Semantic access to INSPIRE: How to publish and query advanced GML data

P Source: http://ceur-ws.org/Vol-798/paper7.pdf

Vanbockryck, J. & Robbrecht, J.

2012 Start to Link, a practical POI approach PPT Source: http://www.poweredbyinspire.eu/documents/0503-linkeddata-

robbrecht.pdf Beckers, V. & Tirry, D. 2013 Linked Open Data: Pilot Project of NGI-Belgium R Source: currently internal (report waiting for approval) De Keyzer, M., Loutas, N., Colas, C. & Goedertier, S.

2013 TM1.2. Introduction to Linked Data (en) PPT Source: https://joinup.ec.europa.eu/community/ods/document/tm12-introduction-

linked-data-en De Keyzer, M., Loutas, N. & Goedertier, S.

2013 TM1.3. Introduction to RDF & SPARQL (en) PPT Source: https://joinup.ec.europa.eu/community/ods/document/tm13-introduction-

rdf-sparql-en Loutas, N., De Keyzer, M. & Goedertier, S.

2013 TM2.3. Design & Manage Persistent URIs (en) PPT Source: https://joinup.ec.europa.eu/community/ods/document/tm23-design-

manage-persistent-uris-en

van den Brink, L., Janssen, P., Quak, W.

2013 From geodata to linked data: Automated Transformation from GML to RDF

BC Source:

http://www.pilod.nl/wiki/Boek/BrinkEtAl-GML2RDF

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Literature study results

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Author(s) Date Title Type Description

Archer, P., Loutas, N. & Goedertier, S.

2013 Cookbook for translating Data Models to RDF Schemas

R Source: https://joinup.ec.europa.eu/community/semic/document/cookbook-

translating-data-models-rdf-schemas

Colas, C., Goedertier, S., Kourtidis, S, Loutas, N. & Rubino, F.

2013 Core Location Pilot - Interconnecting Belgian Address Data

R Source: https://joinup.ec.europa.eu/asset/core_location/document/core-

location-pilot-interconnecting-belgian-address-data

Athanasiou, S. et al. 2013 Deliverable 2.2.1 Integration of External Geospatial Databases

R Source:

http://svn.aksw.org/projects/GeoKnow/Public/D2.2.1_Integration_of_Geospa

tial_Databases.pdf

Williams, H. et al. 2013 Deliverable 2.3.1 Prototype of built in Geospatial Capabilities

R Source:

http://svn.aksw.org/projects/GeoKnow/Public/D2.3.1_Prototype_of_Built-

in_Geospatial_Capabilities.pdf

Ngonga, A., Sherif, M. & Hassan, M.

2013 Deliverable 3.1.1 Development of First Prototype for Spatially Interlinking Data Sets

R Source:

http://svn.aksw.org/projects/GeoKnow/Public/D3.1.1.Development_of_First_

Prototype_for_Spatially.pdf

Wauer, M., Both, A., Stadtler, C. & Isele, R.

2013

Deliverable 6.1.2 Report on Customer Data Preparation

and Transformation for Linked Data Usage

R Source:

http://svn.aksw.org/projects/GeoKnow/Public/D6.1.2_Customer_data_prepa

ration.pdf

GeoKnow 2013 Task 2.7: Exposing INSPIRE data as Linked Data. R Source: http://geoknow.eu/t2-7.html

OGC 2012 GeoSPARQL - A Geographic Query Language for RDF Data

S Source: http://www.opengeospatial.org/standards/geosparql

Abbas, S. & Ojo, A. 2013 Towards a Linked Geospatial Data Infrastructure. P Source: EGOVIS/EDEM 2013: 196-210. DOI: 10.1007/978-3-642-40160-

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Kerry Taylor, K., Lefort, L., Squire, G., Walker, G., Woolf, A., Shu, Y., Ratcliffe, D., Cox, S., Haller, A.

2014

Developing Ontologies for Linked Geospatial Data P

http://www.w3.org/2014/03/lgd/papers/lgd14_submission_41.pdf

Tsinaraki, C., Stavrakantonakis, I. & Christodoulakis, S.

2007 XS2OWL: Representation of XML Schemas in OWL syntax

W

http://www.music.tuc.gr/projects/sw/xs2owl/

Click to edit Master title style INSPIRE community • Tschirner, S., Scherp, A. & Staab, S. -

Semantic access to INSPIRE: How to publish and query advanced GML data

• van den Brink, L., Janssen, P. & Quak, W. - Linking spatial data: automated conversion of geo-information models and GML data to RDF

• Hobona, G., Brackin, R. – OGC OWS-8 Cross Community Interoperability (CCI) Semantic Mediation Engineering Report

• ISO/TC 211 – DIS-19150-2 - Ontology - Part 2: Rules for developing ontologies in the Web Ontology Language (OWL)

• GeoKnow - Task 2.7: Exposing INSPIRE data as Linked Data (and related work)

Linked Data community • Archer, P., Loutas, N. & Goedertier, S.

Cookbook for translating Data Models to RDF Schemas

• Colas, C., Goedertier, S., Kourtidis, S, Loutas, N. & Rubino, F. - Core Location Pilot - Interconnecting Belgian Address Data

• Hyland, B., Atemezing, G. & Villazón-Terrazas, B. - Best Practices for Publishing Linked Data

• ISA Programme – Action 1.1 - Deliverable 3.1 - Process and Methodology for Developing Core Vocabularies

• …

Literature study results

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Literature

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If there is anything relevant missing from our list, please contact us:

are3na@jrc.ec.europa.eu

The list will be provided together with this current presentation.

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Literature study results

Example of project on transformation: Geonovum & TU Delft (Linda van den Brink, Paul Janssen & Wilko Quak)

1. Transforming GML into RDFS/OWL (automated using XSLT)

2. Transforming UML into RDFS/OWL (annotating the UML model)

Motivation for the work

• Currently service based dissemination of GML structured data

• Semantics for predefined domains and clear use cases, controllable

• Not flexible in view of new/revised concepts and relations

• Transformation needed from local sources to INSPIRE data specs

• The use of RDF and GeoSPARQL might be complementary

• RDF transformation can/should be standardized

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Literature study results

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UML data model

(semantics)

GML Application

Schema

RDFS/OWL (ontologies)

RDF

ISO 19150

Issues/challenges for the mapping as defined in ISO • Closed world of UML versus

open world of OWL

• Connection of concepts in UML and related concepts in vocabularies

• Modeling conventions and restrictions in UML

Questions tackled in the research and experiments • Is it possible to describe a generic transformation from GML to RDF without knowledge

about the underlying model?

• How should geometry be encoded in RDF?

• How to transform (automatically) the UML model into RDFS/OWL and can it be integrated with other ontologies on the web

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Literature study results

The experiment - IMRO

• Transformation of GML data to RDFS/OWL (automatically) using GML2RDF

• Elements such as names and descriptions are mapped

• Objects, also nested features, data types and properties are mapped

• Point and surface features transformed to a WKT serialization

• Transformation of UML to RDFS/OWL (semi-automatically) using ShapeChange

• Generation of an OWL vocabulary from GML application schema and UML model

• Improved mapping from UML to OWL by adding information (annotation)

• Attributes

• Classes

• Open issues

• Modifications ShapeChange

• Open-world oriented ontology

• Tackle UML anomalies

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Geonovum Experiments

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Agenda

Introduction

Context

3

2

16

Literature study results

4

5

Sharing your experience – Issues/Challenges?

1

Next steps - Experiments

Sharing your experience – Issues/Challenges?

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Sharing your experience Issues/Challenges?

• From the literature review (so far) and from the discussions in the London workshop several issues can be raised ...

1. It seems that there are too many semantics in UML stereotypes that are not amenable to a generic UML to OWL toolset (Taylor)

• Potentially loss of much of the intrinsic OWL capabilities

• Hampering the interoperability with other RDF datasets

For the transformation of domain models, start over again from scratch for developing an OWL model?

2. Rules for generation of OWL and the work in ISO/TC 211

• Rule-based conversion without harmonization with existing ontologies

• Relating it to other OWL ontologies can be done by using RDFS/OWL mechanisms

• Other set of rules exist (e.g. in ShapeChange)

Do we need to go for a flat rule-based conversion or not?

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Sharing your experience Issues/Challenges?

• From the literature review (so far) and from the discussions in the London workshop several issues can be raised ...

3. Standards for geometry in RDF

• Which standards to use? Debate during the London workshop: GeoSPARQL

• Which alternative? Revise GeoSPARQL ?

• In the Dutch experiments GeoSPARQL was used with the WKT serialization

• Only Simple Feature Geometry and because WKT is compact

• Many vocabularies and extensions exist

4. Other issues ?

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LinkedGeoData Basic Geo GeoRSS

GeoOWL GeoSPARQL

Core Location NeoGeo

...

What are the key public service and policy areas

where INSPIRE-related RDF can be (re)-used

in e-government?

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Agenda

Introduction

Context

3

2

20

Literature study results

4

5

Sharing your experience – Issues/Challenges?

1

Next steps - Experiments

Next steps - Experiments

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Next steps - Experiments

In order to have a common methodology for the experiments some questions have to be answered A first series of questions / ideas based on the elements of Generic Conceptual Model

1. How do you transform the general Feature model? What are the rules used for transforming spatial object types, attributes (spatial, temporal, locational, metadata, thematic), associations, constraints?

2. Which related concepts from existing ontologies can be re-used?

3. Are there any domain independent core vocabularies such as NASA’s sweet ontology, UCUM that could be used for units, dimensions…

4. Which data types will be used for common data types (dates, integers, strings, etc…)

5. How can target classes be identified in UML?

6. How closed or open should the final OWL model be?

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Next steps - Experiments

In order to have a common methodology for the experiments some questions have to be answered A first series of questions / ideas based on the elements of Generic Conceptual Model

7. How to include links to application schema’s, INSPIRE feature concept dictionary, themes, code lists in the OWL schema?

8. How to encode geometry? How to encode raster data?

9. Should a distinction be made between enumerations and code lists? Is there a need to distinguish between different types of code lists (extensible vs non-extensible)

10. How to deal with versioning and lifecycle information in OWL?

11. How to deal with the concept of voidability?

12. How to identify CRS? (now it is part of the geometry literal in GeoSPARQL)

13. How to identify temporal reference systems?

14. …

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Literature

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If there is anything relevant missing from our first list of issues/questions to be

tackled please say so

What are the priorities?

contact us: are3na@jrc.ec.europa.eu

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Next steps

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WEBINAR II: Guidelines & methodologies 5 & 6 May 2014

1. Highlights

2. Refinement

Follow us on Joinup. We will provide the highlights of this

webinar

AND….

At any time, your feedback is very appreciated.

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Next steps

26

Join the collaborative platforms in

other areas of Open Source &

Semantic Interoperability on

https://joinup.ec.europa.eu/

Connecting Geospatial Data

Thank you for your participation!