example for an RDF-XML representation of the NASA-STI categories

definitions_astronomy.xml

<?xml version="1.0"?>

<!-- Definition of Category Astronomy -->
        
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:skos="http://www.w3.org/2004/02/skos/core#">


    <skos:Concept rdf:about="http://mydomain.com/astronomy">

        <skos:definition>Includes observations of celestial bodies; astronomical instruments and techniques; radio, gamma-ray, x-ray, ultraviolet, and infrared astronomy; and astrometry.</skos:definition>

        <skos:prefLabel xml:lang="en">Astronomy</skos:prefLabel>

        <skos:scopeNote>Exhaustive Interest : Except for astrophysics, all facets of astronomy including radio and gamma-ray astronomy, observations of celestial bodies, their structure, motions, and locations.</skos:scopeNote>

        <skos:broader rdf:resource="http://mydomain.com/space+sciences#"/>

        <skos:related rdf:resource="http://dbpedia.org/page/Astronomy"/>

    </skos:Concept>

</rdf:RDF>

definitions_infrared+astronomy.xml

<?xml version="1.0"?>

<!-- Definition of Category infrared astronomy -->

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:skos="http://www.w3.org/2004/02/skos/core#">


    <skos:Concept rdf:about="http://mydomain.com/infrared+astronomy">

        <skos:definition></skos:definition>

        <skos:prefLabel xml:lang="en">infrared astronomy</skos:prefLabel>

        <skos:broader rdf:resource="http://mydomain.com/astronomy#"/>

        <skos:related rdf:resource="http://mydomain.com/space_sciences#"/>

        <skos:related rdf:resource="http://dbpedia.org/page/Infrared"/>

    </skos:Concept>

</rdf:RDF>

definitions_infrared+telescopes.xml

<?xml version="1.0"?>

<!-- Definition of Keyword infrared telescopes -->

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:skos="http://www.w3.org/2004/02/skos/core#">


    <skos:Concept rdf:about="http://mydomain.com/infrared+telescopes">

        <skos:definition></skos:definition>

        <skos:prefLabel xml:lang="en">infrared telescopes</skos:prefLabel>

        <skos:broader rdf:resource="http://mydomain.com/astronomy#"/>

        <skos:related rdf:resource="http://mydomain.com/space_sciences#"/>

        <skos:related rdf:resource="http://dbpedia.org/page/Infrared"/>

    </skos:Concept>

</rdf:RDF>

definitions_rdf-studies.html

Three examples of RDF-SKOS definitions: a keyword, a category and a division taken from NASA-STI (http://www.sti.nasa.gov/sscg/main.html)

Common prefixes:
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

    File 1:
    <!-- defining a keyword as a Concept, at URI = http://mydomain.com/infrared+astronomy# -->

    <http://mydomain.com/infrared+astronomy> rdf:type skos:Concept ;
      skos:prefLabel "infrared astronomy"@en ;
      skos:inScheme <http://mydomain.com/astronomy> ;
      skos:related <http://dbpedia.org/page/Infrared>  .

    File 2:
    <!-- defining a subject as a ConceptScheme, at URI = http://mydomain.com/astronomy# -->

    <http://mydomain.com/astronomy> rdf:type skos:ConceptScheme ;
      skos:prefLabel "Astronomy"@en ;
      skos:definition "definition of Astronomy category in NASA-STI"@en ;
      skos:member <http://mydomain.com/infrared+astronomy> , <http://mydomain.com/extrasolar+planets> , <etc> .

    File 3:
    <!-- defining a division as a Collection, at URI = http://mydomain.com/space_sciences# -->

    <http://mydomain.com/space_sciences> rdf:type skos:Collection ;
      skos:prefLabel "Space Sciences"@en ;
      skos:definition "definition of Space Science division in NASA-STI"@en ;
      skos:member <http://mydomain.com/astronomy> , <http://mydomain.com/astrophysics> , <etc> .


XML-SKOS EXAMPLE for a WEBPAGE


<!-- Namespace definitions -->

<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:skos="http://www.w3.org/2004/02/skos/core#">


<!-- rdf description (using skos namespace) -->

  <skos:Concept rdf:about="http://www.nasa.gov/mission_pages/nustar/news/nustar20130829.html">

    <skos:definition>a webpage about nustar and x-ray</skos:definition>

    <skos:prefLabel xml:lang="en">NuSTAR Delivers the X-Ray Goods</skos:prefLabel> <!-- title -->

    <skos:altLabel xml:lang="en">NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is giving the wider astronomical community a first look at its unique X-ray images of the ...</skos:altLabel>

    <skos:broader rdf:resource="http://mydomain.com/NASA_mission"/>

    <skos:related rdf:resource="http://mydomain.com/x-ray+astronomy#"/>
    <skos:related rdf:resource="http://mydomain.com/space_sciences#"/>
    <skos:related rdf:resource="http://mydomain.com/astronomy#"/>

  </skos:Concept>

</rdf:RDF>


EXAMPLE JSON-LD (http://json-ld.org/playground/index.html)

{
  "@context": {
    "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
    "skos": "http://www.w3.org/2004/02/skos/core#"

  },
  "rdf:about":"http://www.nasa.gov/mission_pages/nustar/news/nustar20130829.html",
  "skos:prefLabel": "NuSTAR Delivers the X-Ray Goods",
  "skos:related": "http://mydomain.com/x-ray+astronomy#",
  "skos:related": "http://mydomain.com/astronomy#",
  "skos:related": "http://mydomain.com/space+sciences#"
}