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.
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
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