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GLUES


About

As part of the BMBF funded project GLUES, 52°North supports the efforts in building up an SDI for scientific geodata. The data comes from various regional subprojects all over the world.

The lead for developing the GLUES SDI is the Technical University Dresden (TUD) and the contact point is Stephan Mäs.

A central component of the GLUES SDI is the GLUES geoportal as well as the CSW server which acts as a central hub to the different datasets.

Contact

GLUES team at 52°North: Christoph Stasch, BenjaminPross, DanielNuest (former member: ArneBroering)


Linked Data to support the GLUES SDI

To improve the discovery of GLUES data sets, we investigate the usage of Linked Data. The white paper describes an approach for integrating Linked Data and SDI.

In short, the LOD services and websites below contain a mirror of the GLUES catalog's data. The mirror is created by a Java tool that reads the catalog via the CSW interface, transforms the XML to RDF, and inserts it into a triple store.

Mapping from CSW to LOD

The mapping from CSW to LOD is not formally defined but was implemented in an agile manner as part of the software project CSWLoDEnabler (see description below). The following class implements the mapping: https://github.com/52North/CSWLoDEnabler/blob/6bda37fbf5ccc8ea31125d3c334e15db8cfc6f06/src/main/java/org/n52/lod/csw/mapping/CSWtoRDFMapper.java

There exists a WPS process to start the CSWLoDEnabler and create up-to-date LOD. More information here: CSWLoDEnablerStarter

Used vocabularies

The following vocabularies are used in the GLUES LOD:

Services

SPARQL endpoint

Fictitious (just as didactic example): http://example.org:8890/sparql

Example Queries

All members of the project
PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
SELECT *
WHERE {
    <http://example.org/glues-lod/project/GLUES> foaf:member ?m .
}

Live link

Identifiers and titles of all datasets

PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>

SELECT ?id ?title
WHERE {
    ?dataset dc:type "http://example.org/glues-lod/types/dataset" .
    ?dataset dc:identifier ?id .
    ?dataset dc:title ?title .
}

Live link (RDF format)

Names and role of all people working at TU Dresden (within GLUES)
PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>

SELECT ?name ?r
WHERE {
    <http://example.org/glues-lod/organization/TU-Dresden> foaf:member ?person .
    ?person foaf:name ?name .
    ?person vcard:ROLE ?r .
}

Live link

Names of all datasets published by scientists from UFZ
PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>

SELECT ?name ?dataset
WHERE {
    <http://example.org/glues-lod/organization/UFZ> foaf:member ?person .
    ?person foaf:name ?name .
    ?person vcard:ROLE ?role .
    FILTER regex(?role, "Scientist" ) .
    ?dataset dc:publisher ?person .
}

Live link

Boundingbox query

SELECT ?object ?pg
WHERE
  {
    ?object <http://geovocab.org/geometry#geometry> ?pt.
    ?pt <http://www.opengis.net/ont/geosparql#asWKT> ?pg.
    FILTER
     (
      bif:st_intersects
       (
        bif:st_geomfromtext
         (
          "BOX(100 10, 110 30)"
         ),
         ?pg
       )
     )
  }

Live link

All datasets derived from glues:lmu:metadata:dataset:agriculturallandevaluationgrowingcycle
PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>
PREFIX prov: <http://www.w3.org/ns/prov#>

SELECT ?dataset
WHERE {
    ?dataset dc:type "http://example.org/glues-lod/types/dataset" .
    ?dataset prov:wasDerivedFrom ?dataset2 .
    ?dataset2 dc:identifier ?id
    FILTER regex(?id, "glues:lmu:metadata:dataset:agriculturallandevaluationgrowingcycle" ) .
}

Live link

All process steps conducted by UFZ personnel
PREFIX foaf:  <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>
PREFIX prov: <http://www.w3.org/ns/prov#>

SELECT ?name ?process
WHERE {
    <http://example.org/glues-lod/organization/UFZ> foaf:member ?person .
    ?person foaf:name ?name .
    ?process prov:wasAssociatedWith ?person .
}

Live link

Pubby

HTML browsing of LOD resources based on the SPARQL endpoint.

Software Projects

We investigated specifically the integration of the GLUES CSW server (a standardized OGC Catalog) with Linked Data. To achieve this integration, we developed a tool, called the CSWLoDEnabler, which (1.) crawls a CSW by querying all available resources in ISO 19115 format and (2.) translates those resources to the RDF format using well-known vocabularies and (3.) inserts the RDF resources into a triple store.

The code repository of the CSWLoDEnabler is available here: https://github.com/52North/CSWLoDEnabler

Deployment Documentation

The triple store is a Virtuoso Server providing a SPARQL endpoint.

For quick browsing, Pubby is used and provides an HTML view of available Linked Data resources.

Provenance

See GLUES Linked Data Provenance Google Doc

Reproducible Scientific Geoprocesses

Based on WPS4R the GLUES team work on publishing scientific analyses based on the R programming language and software environment for statistical computing and graphics. WPS4R is a collaboration platform that allows scientists to extend their R scripts with comments so that the script can be published in a standardized Web Processing Service (WPS).

Servers

TUD Server

Topic revision: r30 - 28 Feb 2020, christophgossen
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