var D2R_namespacePrefixes = {
    rdf: 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
    rdfs: 'http://www.w3.org/2000/01/rdf-schema#',
    owl: 'http://www.w3.org/2002/07/owl#',
    dc: 'http://purl.org/dc/elements/1.1/',
    foaf: 'http://xmlns.com/foaf/0.1/',
    swrc: 'http://swrc.ontoware.org/ontology#',
    'swrc-ext': 'http://www.cs.vu.nl/~mcaklein/onto/swrc_ext/2005/05#',
    geo: 'http://www.w3.org/2003/01/geo/wgs84_pos#',
    ical: 'http://www.w3.org/2002/12/cal/ical#',
    swc: 'http://data.semanticweb.org/ns/swc/ontology#',
};