Table of Contents
0 IntroductionIn this document, Qualified Dublin Core ([DC15], [DCQual]) is encoded in terms of RDF, the Resource Description Framework as defined by the RDF Model & Syntax Specification [RDFMS] (XML namespace for RDF [RDFName]), a W3C recommendation. The RDF Schema specification 1.0 [RDFS] is also used (XML Namespace for RDFS [RDFSName]) which is a W3C candidate recommendation. Quite often the notion of a URI (Uniform Resource Identifier) is used which is defined by RFC 2396 [URI]. The notion of URI embraces URL and URN. We also discuss collaboration of qualified DC with other vocabularies and the DumbDown algorithm. An explicit encoding is provided for classical classification systems and thesauri. Additionally a procedure is discussed to create encoding for more general schemes. One of the major changes with respect to the Guidance on expressing the Dublin Core within the RDF ([DM]) is the more systematic use of RDF Schema.
More specific RDF issues will be described later in this document. Basic Observation: DC Elements correspond to RDF properties.1 Unqualified DC: The hedgehog modelThe following graph re-expresses unqualified DC in HTML in
RDF in a schematic way. There is a tiny bit of extra
information in the hedgehog model as opposed to HTML: all
assertions made are about a fixed resource. (Throughout this
document resources are indicated by 
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:creator>a</dc:creator>
<dc:contributor>b</dc:contributor>
<dc:publisher>c</dc:publisher>
<dc:subject>d</dc:subject>
<dc:description>e</dc:description>
<dc:identifier>f</dc:identifier>
<dc:relation>g</dc:relation>
<dc:source>h</dc:source>
<dc:rights>i</dc:rights>
<dc:format>j</dc:format>
<dc:type>k</dc:type>
<dc:title>l</dc:title>
<dc:date>m</dc:date>
<dc:coverage>n</dc:coverage>
<dc:language>o</dc:language>
</rdf:Description>
</rdf:RDF>
Note that all DC properties are optional and repeatable. 1.1 Example
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:creator>Karl Mustermann</dc:creator>
<dc:title>Algebra</dc:title>
<dc:subject>mathematics</dc:subject>
<dc:date></dc:date>
<dc:language>EN</dc:language>
<dc:description>An introduction to algebra</dc:description>
</rdf:Description>
</rdf:RDF>
The graph given by the hedgehog model is unsatisfactory in various respects. In particular there is no way to provide structure for a resource discovery process. 2 Qualified DCThe DCMI has recognized two broad classes of qualifiers. We collect from the Qualifier Recommendation the information we need.
2.1 Element RefinementThe first issue for qualification is what DCMI calls Element refinement. RDFS provides a special property for this kind of semantic refinement:
2.1.2 Example
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dcterms:abstract>The paper resolves the issues of the data model
draft.
</dcterms:abstract>
</rdf:Description>
<rdf:Description rdf:about="http://purl.org/dc/terms/abstract">
<rdfs:subPropertyOf
rdf:resource="http://purl.org/dc/elements/1.1/description"/>
</rdf:Description>
</rdf:RDF>
Here three new features of RDF are being used:
2.1.3 RemarkOther communities can also use
The declaration of 2.1.4
An earlier version of the data model draft ([DM]) did not make use of RDFS and instead introduced an ad-hoc work around, which was cumbersome if one wanted to refine for instance the notion of dcterms:abstract further. Basically this is all that one has to say about element refinement. The flexible notion of subProperty frees us from the HTML dot notation. It gives room for transparent encoding of partial orderings on refinements of given elements. A draft for an RDF Schema Declaration for the element refinements specified in the DC Qualifiers recommendation is given in [DCQS]. 2.1.5 RemarkThere are relations between parts of RDF Vocabulary and DC Vocabulary which can be seen by reviewing the definitions.
2.1.5.3Note that 2.1.5.4
2.1.5.5Note that the direction of the
For example, although the definitions of
2.2 Repeated Properties and ``MetaMetaData''All Dublin Core Elements are repeatable. Repeating element E has as basic meaning: The objects which are values of the element E all are related to the subject under description by the relation element E. In RDF, properties can be repeated:
all the properties are
asserted (or logically Sometimes one wants to explicitly say something slightly different: the objects fulfill the relation E as a group, either in a particular order or in any order or as alternatives with respect to E. RDF allows the marking of such relationships by creating new
resources from the given objects in three different ways,
called 2.2.1 Repeating Properties - AND
The three constructions 2.2.2 Bag
Such a Bag may or may not have a public URI. The same applies to resources of type Person. In the example below the bag construction is used with otherwise unqualified Dublin Core. Even in this form the meaning differs from the previous AND Example. Jon Doe and Karin Mustermann together formed an entity, which as such represents a creator. The order in the record is an artifact of the coding and nothing else.
2.2.3 SeqSome academic circles expect some meaning from the ordering
of author names. This can be modeled with the Below we describe a use of
2.2.4 Alt
Another typical application of 2.2.5 WarningThe RDF Container 2.2.6 ReificationOne often wants to express some kind of authority on a given assertion. RDF here offers a method called Reification. Despite it's awkward name and seemingly complicated representation as a graph, Reification is hardly more than providing a resource for an assertion, one can reference. A reification unambiguously identifies the assertion, it provides a resource for. To that objective explicitly subject, object and predicate of the assertion are given in the graph representation. The general method of Reification avoids the introduction of particular vocabulary for ``MetaMetaData'', but makes the Dublin Core Vocabulary available in that situation also.
2.3 Encoding SchemesOne may view But there are simpler structures, which one may think about first. Perhaps the simplest case of value encoding (above the basic character representation rules which come from using XML for RDF transport) is that of a classic subject classification scheme. Typically here we have a code - some obscure string - and a caption, which is (supposed to be) human understandable. This sounds like providing a value/label pair. In the case where there is a URI, specifying the object we
want to use in it's relation with the scheme, we could make an
2.3.1 Poor Man's Structured Values
<?xml version="1.0" ?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<Description>
<dc:subject>
<Description>
<value>19D10</value>
<rdfs:label>Algebraic K-Theory of spaces</rdfs:label>
<rdfs:isDefinedBy rdf:resource="URI2"/>
</Description>
</dc:subject>
</Description>
</RDF>
2.3.2 Remark: value/label modelIf there is some RDF Class given to identify the Scheme, we might know how to process the value and also how to take advantage of a partial order within the scheme itself. If the Class definition has a machine understandable form of how to process thevalue, one can dispense with the
rdfs:isDefinedBy on the resource itself, but in
general this is not very likely to happen. The Thesaurus - like
case was already briefly discussed in connection with the
Alt container. Please observe, that
rdfs:label by definition must target literal
content and cannot be processed by RDF any further.
2.3.3 RemarkNote that it is NOT required that It can become necessary to repeat
2.3.5 RemarkAs long as it is possible to embed iterated poor man's structured values in the sense of the DC Model section, a record can be viewed as qualified DC compliant and can expect a useful interpretation at least on the unqualified DC level. 2.3.6 RemarkSome properties one might want to use may not be
subordinated to any DC Element at all in their definition, but
if in addition a DC Element or one of its refinements applies
(i.e. there is semantic overlap) then RDF's 2.3.7 RemarkThe notion of Microprofile seems useful in this context. One is tempted to construct Application Profiles from such micro structures which in themselves rest on primitive Data - Types. Some work in this direction is documented at CARMEN AP6. Such a procedure is in particular advisable in the area where MetaData meets Data. This for instance happens in the notations for dates and locations. The work done on data typing in XML - Schema appears relevant. An integration of XML Schema data types with RDF in general is proposed in [DAML+OIL]. It fits with value/label model and is basically compliant with the cooperation of Dublin Core with other vocabularies as discussed in section 3. DCMI recommended Schemes for dates and locations will be dealt with in a separate document. 2.3.8 URI Identifier Scheme
[RDFMS] gives the URI scheme a
privileged role with respect to resources. There is no
particular processing instruction required once a URI is given.
We simply can call a resource by the 2.3.8.1 Example
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:identifier rdf:resource="http://www.myorg"/>
</rdf:Description>
</rdf:RDF>
In case one will not use URI as labeling scheme for resources or one is not satisfied with a simple string without further processing instructions,
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:identifier>1234564TGRF</dc:identifier>
</rdf:Description>
</rdf:RDF>
then one should proceed as described in general at the beginning of this paragraph to construct a DC compliant RDF encoding. 2.3.9 Subject Schemes
For each DCMI recommended encoding scheme an RDFS class is defined by the DC Terms RDF Schema. 2.3.9.1 Example
The following RDF/XML is a fragment from the DC Terms RDF Schema. < -- Class definition -- > <rdfs:Class rdf:about="http://purl.org/dc/terms/MESH"> <rdfs:label>MeSH</rdfs:label> <rdfs:comment>Instances of this class are Medical Subject Headings and must provide an rdf:value (with content the code) and should provide an rdfs:label arc (with content the caption). </rdfs:comment> <rdf:type rdf:resource = "http://purl.org/dc/terms/SubjectScheme" /> <rdfs:isDefinedBy rdf:resource="http://purl.org/dc/terms/" /> </rdfs:Class> 2.3.9.2 Example: Usage of a MeSH object as subject.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dc:subject>
<dcterms:MESH>
<rdf:value>D</rdf:value>
<rdfs:label>Formate Dehydrogenase</rdfs:label>
</dcterms:MESH>
</dc:subject>
</rdf:Description>
</rdf:RDF>
2.3.10 Language Schemes
For each DCMI recommended encoding scheme an RDFS class is defined by DC Terms RDF Schema. 2.3.10.1 Example
The following RDF/XML is a fragment from the DC Terms RDF Schema:
<rdfs:Class rdf:about="http://purl.org/dc/terms/RFC1766">
<rdfs:label>RFC1766</rdfs:label>
<rdfs:comment>Internet RFC 1766 'Tags for the identification of Language'
specifies a two letter code taken from ISO 639, followed optionally by a
two letter country code taken from ISO 3166.</rdfs:comment>
<rdf:type rdf:resource = "http://purl.org/dc/terms/LanguageScheme" />
<rdfs:seeAlso rdf:resource = "http://www.ietf.org/rfc/rfc1766.txt" />
<rdfs:isDefinedBy rdf:resource="http://purl.org/dc/terms/" />
</rdfs:Class>
2.3.10.2 Example: Usage of a RFC1766 object as language.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dc:language>
<dcterms:RFC1766>
<rdf:value>EN</rdf:value>
<rdfs:label>English</rdfs:label>
</dcterms:RFC1766>
</dc:language>
</rdf:Description>
</rdf:RDF>
2.3.11 Format Schemes
For each DCMI recommended encoding scheme an RDFS class is defined by DC Terms RDF Schema. 2.3.11.1 Example
The following RDF/XML is a fragment from the DC Terms RDF Schema:
<rdfs:Class rdf:about="http://purl.org/dc/terms/IMT">
<rdfs:label>IMT</rdfs:label>
<rdfs:comment>
Instances of this class are the Internet media types
</rdfs:comment>
<rdf:type rdf:resource="http://purl.org/dc/terms/FormatScheme"/>
<rdfs:isDefinedBy rdf:resource="http://purl.org/dc/terms/"/>
<rdfs:seeAlso
rdf:resource="http://www.isi.edu/in-notes/iana/assignments/media-types/media-types"/>
</rdfs:Class>
2.3.11.2 Example: Usage of an IMT object as format.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://prul.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dc:format>
<dcterms:IMT>
<rdf:value>text/html</rdf:value>
<rdfs:label>HTML</rdfs:label>
</dcterms:IMT>
</dc:format>
</rdf:Description>
</rdf:RDF>
2.3.12 Type Schemes
For each approved term given by the DCMI Type Vocabulary a RDFS class is defined in the RDF Schema for DCMI Type. 2.3.12.1 Example
The following RDF/XML is a fragment from the DC Terms/DCMI Types RDF Schema:
<!-- class of type classes -->
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/"
xmlns:dctype="http://purl.org/dc/dcmitype/">
<rdfs:Class rdf:about="http://purl.org/dc/dcterms/DCMIType">
<rdfs:label>DCMI Type Vocabulary</rdfs:label>
<rdfs:comment>A list of types used to categorize the nature or
genre of the content of the resource.</rdfs:comment>
<rdf:type
rdf:resource="http://purl.org/dc/terms/TypeScheme"/>
<rdfs:seeAlso
rdf:resource="http://purl.org/dc/dcmitype/"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:isDefinedBy
rdf:resource="http://purl.org/dc/dcterms/"/>
</rdfs:Class>
<!-- Example: Image -->
<rdfs:Class rdf:about="http://purl.org/dc/dcmitype/Image">
<rdfs:label>Image</rdfs:label>
<rdfs:isDefinedBy
rdf:resource="http://purl.org/dc/dcmitype/"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
An image is a primarily symbolic visual representation other than text.
For example - images and photographs of physical objects, paintings,
prints, drawings, other images and graphics, animations and moving
pictures, film, diagrams, maps, musical notation. Note that image may
include both electronic and physical representations.
</rdfs:comment>
<rdf:type rdf:resource="http://purl.org/dc/dcterms/DCMIType"/>
</rdfs:Class>
</rdf:RDF>
2.3.12.2 Example: Usage of Image as type.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dctype="http://purl.org/dc/dcmitype/">
<dctype:Image>
<dc:creator>Carl</dc:creator>
</dctype:Image>
</rdf:RDF>
2.3.13 Date Schemes
For each DCMI recommended encoding scheme an RDFS class is defined by DC Terms RDF Schema. 2.3.13.1 Example
The following RDF/XML is a fragment from the DC Terms RDF Schema: <rdfs:Class rdf:about="http://purl.org/dc/terms/W3CDTF"> <rdfs:label>W3C-DTF</rdfs:label> <rdfs:comment>Instances of this class are dates and times encoded with the W3C Encoding rules - a profile based on ISO8601 </rdfs:comment> <rdf:type rdf:resource = "http://purl.org/dc/terms/DateScheme" /> <rdfs:seeAlso rdf:resource = "http://www.w3.org/TR/NOTE-datetime" /> <rdfs:isDefinedBy rdf:resource="http://purl.org/dc/terms/" /> </rdfs:Class> 2.3.13.2 Example: Usage of a W3C-DTF object as date.
The following RDF/XML is a fragment from the DC Terms RDF Schema:
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dc:date>
<dcterms:W3CDTF>
<rdf:value>T14:20+10:00</rdf:value>
</dcterms:W3CDTF>
</dc:date>
</rdf:Description>
</rdf:RDF>
2.3.14 Coverage Schemes
For each DCMI recommended encoding scheme an RDFS class is defined by DC Terms RDF Schema. 2.3.14.1 Example
The following RDF/XML is a fragment from the DC Terms RDF Schema:
<rdfs:Class rdf:about="http://purl.org/dc/terms/Point">
<rdfs:label>DCMI Point</rdfs:label>
<rdfs:comment>
DCMI Point is used for identifying a point in space using
its geographic coordinates
</rdfs:comment>
<rdf:type
rdf:resource="http://purl.org/dc/terms/SpatialScheme"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/2000/07/28/dcmi-point/"/>
<rdfs:isDefinedBy
rdf:resource="http://purl.org/dc/terms/"/>
</rdfs:Class>
2.3.14.2 Example using DCMI Point as coverage.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description>
<dc:coverage>
<dcterms:Point>
<rdfs:label>Perth</rdfs:label>
<rdf:value>
name=Perth, W.A.; east=115.85717; north=-31.95301
</rdf:value>
</dcterms:Point>
</dc:coverage>
</rdf:Description>
</rdf:RDF>
3 DC in collaboration with other vocabularies and DumbDownThe DC has proven to be able to interact with other vocabularies and community defined schemes. The following more or less well known example shows how it works with vCard as suggested in [VCARD]. In view of the DumbDown algorithm which we will discuss in section 3.2, one only has to give a useful rdfs:label to follow. This is particularly easy with vCard for it provides the full name of the person as a literal value. 3.1 Example3.1.1 Using vCard with Dublin Core
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:vCard = "http://www.w3.org/2001/vcard-rdf/3.0#">
<rdf:Description>
<dc:creator>
<rdf:Description rdf:about = "http://qqqfoo.com/staff/corky" >
<rdfs:label> Corky Crystal </rdfs:label>
<vCard:FN> Corky Crystal </vCard:FN>
<vCard:N rdf:parseType="Resource">
<vCard:Family> Crystal </vCard:Family>
<vCard:Given> Corky </vCard:Given>
<vCard:Other> Jacky </vCard:Other>
<vCard:Prefix> Dr </vCard:Prefix>
</vCard:N>
<vCard:BDAY> </vCard:BDAY>
</rdf:Description>
</dc:creator>
</rdf:Description>
</rdf:RDF>
3.1.2 Math-NetThis is a more elaborate example that uses some vocabulary from Math-Net Schemes in addition to the vCard vocabulary. See section 3.2 how this metadata description is mapped to unqualified Dublin Core by the DumbDown algorithm.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rdf:RDF [
<!ENTITY mnpns 'http://www.iwi-iuk.org/material/RDF/1.1/Schema/Property/mnp#'>
]>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/1999/02/22-rdf-schema-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/"
xmlns:mnp="&mnpns;"
xmlns:mn="http://www.iwi-iuk.org/material/RDF/1.1/Schema/Class/mn#"
xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">
<!--
subPropertyOf relations
encoded in the .../mnp# Namespace
-->
<rdf:Description
rdf:about="&mnpns;primarySubject">
<rdfs:subPropertyOf
rdf:resource="http://purl.org/dc/elements/1.1/subject"/>
</rdf:Description>
<rdf:Description
rdf:about="&mnpns;secondarySubject">
<rdfs:subPropertyOf
rdf:resource="http://purl.org/dc/elements/1.1/subject"/>
</rdf:Description>
<!-- An example file -->
<mn:Preprint>
<dc:title>Algebra</dc:title>
<dc:creator>
<rdf:Bag>
<rdf:li>
<mn:Person>
<vCard:FN>John Smith</vCard:FN>
<rdfs:label>John Smith</rdfs:label>
<vCard:EMAIL>smith</vCard:EMAIL>
<vCard:N rdf:parseType="Resource">
<vCard:Family>Smith</vCard:Family>
<vCard:Given>John</vCard:Given>
</vCard:N>
</mn:Person>
</rdf:li>
</rdf:Bag>
</dc:creator>
<dcterms:created>
<dcterms:W3CDTF>
<rdf:value></rdf:value>
<rdfs:label>25 September 1999</rdfs:label>
</dcterms:W3CDTF>
</dcterms:created>
<dc:identifier>
<rdf:Alt>
<rdf:li rdf:resource="http://www.math.org/doc.ps"/>
<rdf:li rdf:resource="http://www.math.org/doc.html"/>
</rdf:Alt>
</dc:identifier>
<mnp:primarySubject>
<mn:MSC2000>
<rdf:value>15-06</rdf:value>
<rdfs:label>Proceedings, conferences, collections, etc. </rdfs:label>
</mn:MSC2000>
</mnp:primarySubject>
<mnp:secondarySubject>
<mn:MSC2000>
<rdf:value>15A12</rdf:value>
<rdfs:label>Conditioning of matrices</rdfs:label>
</mn:MSC2000>
</mnp:secondarySubject>
<dcterms:abstract>An introduction to algebra</dcterms:abstract>
<dc:subject>algebra, function, relation</dc:subject>
</mn:Preprint>
<!-- Formats -->
<rdf:Description rdf:about="http://www.math.org/doc.ps">
<dc:format>
<dcterms:IMT rdf:value="application/PostScript"
rdfs:label="Postscript Document">
</dcterms:IMT>
</dc:format>
</rdf:Description>
<rdf:Description rdf:about="http://www.math.org/doc.html">
<dc:format>
<dcterms:IMT rdf:value="text/html"
rdfs:label="HTML Document">
</dcterms:IMT>
</dc:format>
</rdf:Description>
<!-- /Formats -->
</rdf:RDF>
3.2 DumbDown AlgorithmThe goal of a DumbDown algorithm is to provide a useful approximation of RDF graphs extending qualified DC with other vocabularies by a set of unqualified DC hedgehogs. The algorithm is described below and extends the version originally given in [DC]. The algorithm gives preference to the linking of Dublin Core
with other vocabulary by means of Particular emphasis is given to close approximation of the RDF/S concepts. 3.2.1 An Extended DumbDown AlgorithmThis algorithm creates from an arbitrary RDF graph containing Dublin Core elements (or subPropertyOf Dublin Core elements) a (new) RDF graph whose arcs are all given by the 15 Dublin Core elements pointing to an 'appropriate literal'. Suppose we have a property X which has been recognized as a subProperty of a DC15 element Y or is itself a DC15 element and R --- X ---> N is contained in the given RDF graph. (In particular the subPropertyOf relations mentioned in section 2.1.5 are recognized.) The function dumbDownOf(Y,N) described below returns a set n1,...,nk of 'appropriate literals' for this property. For each returned value ni an arc R --- Y --> ni starts at the resource R in the result graph.
dumbDownOf(dc:property,N):
1. if the Node N is a literal we have unqualified Dublin Core. Return the
literal.
2. else the Node N is a resource:
2.1 if dc:property is in {dc:identifier,dc:source,dc:relation}
/* In this case the algorithm should preferably calculate a URI */
2.1.1 if N is a Bag or Sequence: return the literal that is
calculated by dumbDown_Bag_Seq(dc:property,N).
2.1.2 if N is an Alt: return the literals that are
calculated by dumbDown_Alt(dc:property,N).
2.1.3 if N is given a fully expanded URI return the string (literal)
given by the URI.
2.1.4 if N has rdfs:label arcs: return the set of literals that are
target of those arcs.
2.1.5 if N has rdf:value arcs: return the union of sets of literals
calculated by dumbDown(dc:property,V) for every Node V that
is target of an rdf:value arc.
2.1.6 else: return empty set.
2.2 else:
2.2.1 if N has rdfs:label arcs: return the set of literals that are
target of those arcs.
2.2.2 if N has rdf:value arcs: return the union of sets of literals
calculated by dumbDown(dc:property,V) for every Node V that
is target of an rdf:value arc.
2.2.3 if N is a Bag or Sequence: return the literal that is
calculated by dumbDown_Bag_Seq(dc:property,N).
2.2.4 if N is an Alt: return the literals that are
calculated by dumbDown_Alt(dc:property,N).
2.2.5 if N has dc:title arcs:return the union of sets of literals
calculated by dumbDown(dc:property,V) for every Node V that
is target of a dc:title arc.
2.2.6 if N is given a fully expanded URI return the string (literal)
given by the URI.
2.2.7 else: return empty set.
Subroutines:
dumbDown_Bag_Seq(dc:property,N):
Let N_1,...,N_n denote the elements of the container N.
Join the strings (literals) calculated by dumbDownOf(dc:property,N_i)
(for all elements) separated by "; ". Return *the* constructed string.
dumbDown_Alt(dc:property,N):
Let N_1,...,N_n denote the elements of the container N.
Return the set of literals calculated by dumbDownOf(dc:property,N_i)
(for all elements).
This algorithm terminates.
3.2.2 Garbage collectionThe resulting graph constructed by the DumbDown algorithm described in section 3.2.1 may contain some useless information in terms of isolated subgraphs of the following form:
It is recommended to delete isolated arcs that start at an
anonymous resource, are labeled with There might be further application-specific requirements for refining the resulting graph of the DumbDown algorithm. 3.2.3 Demonstration of DumbDownThe [CARA] based online Demo [DDD] already has 'recognized' the subPropertyOf relations in the DCQ namespace as proposed in the DC Term RDF Schema Draft (section 5.1). 3.2.4 ExampleThe example given in section 3.1.2 results in the following DC15 description:
4 Language qualificationRDF/XML allows for the general XML language attribute
4.1 Example
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:creator>Karl Mustermann</dc:creator>
<dc:title>Algebra</dc:title>
<dc:subject xml:lang="en">mathematics</dc:subject>
</rdf:Description>
</rdf:RDF>
The following is a valid RDF graph representation (with respect to [RDFMS]):
4.1.1 NoteThe working draft RDF/XML Syntax Specification
(Revised) [RDFMSRev] (issued 25
March 2002) of W3C's RDF Core Working Group suggests a
change to [RDFMS] in the treatment of
Section
[RDFMSRev, 3.1.2] requires parsers to keep
This solution of the 4.2 Poor mans language qualificationApplications, which want language qualification accessible on the level of RDF triples, are recommended to employ a poor man's approach as in the following example: 4.2.1 Example
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description>
<dc:creator>Karl Mustermann</dc:creator>
<dc:title>Algebra</dc:title>
<dc:subject>
<rdf:Description dc:language="en">
<rdf:value xml:lang="en">mathematics</rdf:value>
</rdf:Description>
</dc:subject>
</rdf:Description>
</rdf:RDF>
4.3 RemarkNote that the Further qualification of the 5 AppendixThe code in this section is for example only and is not normative. Up to date RDF Schema declarations will be published elsewhere on the DCMI web site. 5.1 DC Terms RDF Schema DraftNote added in proof: In May 2002 the dc-usage board
has approved a property
<?xml version="1.0"?>
<!--
Previous Version:
RDF Schema declaration for the Qualified Dublin Core Element
Set 2000/03/13
(comments to Eric Miller, emiller)
This Version:
RDF Schema declaration Draft for the Qualified Dublin Core
Element Set 2002/05/15
(comments to DC Architecture WG,
http://www.jiscmail.ac.uk/lists/dc-architecture.html)
-->
<!DOCTYPE rdf:RDF [
<!ENTITY rdfns 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
<!ENTITY rdfsns 'http://www.w3.org/2000/01/rdf-schema#'>
<!ENTITY dcns 'http://purl.org/dc/elements/1.1/'>
<!ENTITY dctermsns 'http://purl.org/dc/terms/'>
<!ENTITY dctypens 'http://purl.org/dc/dcmitype/'>
]>
<rdf:RDF
xmlns:rdf="&rdfns;"
xmlns:rdfs="&rdfsns;"
xmlns:dc="&dcns;"
xmlns:dcterms="&dctermsns;"
xmlns:dctype="&dctypens;">
<!-- Description of this Schema -->
<rdf:Description rdf:about="&dctermsns;">
<dc:title>The Dublin Core Terms namespace providing access
to it's content by means of an RDF Schema</dc:title>
<dc:publisher>The Dublin Core Metadata Initiative</dc:publisher>
<dc:description>The Dublin Core Terms namespace provides URIs for the
Dublin Core Element Set Qualifier Vocabulary. Vocabulary terms are
declared using RDF Schema language to support RDF applications.
The Dublin Core qualifiers form a richer vocabulary,
which is intended to facilitate discovery of resources.
</dc:description>
<dc:language>English</dc:language>
<dcterms:requires rdf:resource="http://www.dublincore.org/documents/2000/07/11/dcmes-qualifiers/"/>
<dc:source rdf:resource="http://www.dublincore.org/documents/2000/07/11/dcmes-qualifiers/"/>
</rdf:Description>
<!-- Begin: Title -->
<!-- Title refinement declarations -->
<rdf:Property rdf:about="&dctermsns;alternative">
<rdfs:label>Alternative</rdfs:label>
<rdfs:comment>Any form of the title used as a substitute or
alternative to the formal title of the resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource = "&dcns;title" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
</rdf:Property>
<rdf:Description rdf:about="&rdfsns;label">
<rdfs:subPropertyOf rdf:resource="&dcns;title"/>
</rdf:Description>
<!-- End: Title Declaration -->
<!-- End: Title -->
<!-- Begin: Subject -->
<!-- Encoding Scheme declarations -->
<rdfs:Class rdf:about="&dctermsns;SubjectScheme">
<rdfs:label>Subject Encoding Schemes</rdfs:label>
<rdfs:comment>A set of subject encoding schemes
and/or formats</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;LCSH">
<rdfs:label>LCSH</rdfs:label>
<rdfs:comment>Library of Congress Subject Headings
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SubjectScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;LCC">
<rdfs:label>LCC</rdfs:label>
<rdfs:comment>Library of Congress Classification
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SubjectScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
<rdfs:seeAlso
rdf:resource="http://lcweb.loc.gov/catdir/cpso/lcco/lcco.html"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;DDC">
<rdfs:label>DDC</rdfs:label>
<rdfs:comment>Dewey Decimal Classification
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SubjectScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
<rdfs:seeAlso
rdf:resource="http://www.oclc.org/dewey/index.htm"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;UDC">
<rdfs:label>UDC</rdfs:label>
<rdfs:comment>Universal Decimal Classification
</rdfs:comment>
<rdf:type rdf:resource = "&dctermsns;SubjectScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
<rdfs:seeAlso
rdf:resource="http://www.udcc.org/"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;MESH">
<rdfs:label>MeSH</rdfs:label>
<rdfs:comment>Medical Subject Headings
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SubjectScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
<rdfs:seeAlso
rdf:resource="http://www.nlm.nih.gov/mesh/meshhome.html"/>
</rdfs:Class>
<!-- End: Subject -->
<!-- Begin: Description -->
<!-- Description refinement declarations -->
<rdf:Property rdf:about="&dctermsns;abstract">
<rdfs:label>Abstract</rdfs:label>
<rdfs:comment>A summary of the content of the resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;description"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;tableOfContents">
<rdfs:label>Table Of Contents</rdfs:label>
<rdfs:comment>A list of subunits of the content of the resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;description"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Description rdf:about="&rdfsns;comment">
<rdfs:subPropertyOf rdf:resource="&dcns;description"/>
</rdf:Description>
<!-- End: Description -->
<!-- Begin: Date -->
<!-- Date refinement declaration -->
<rdf:Property rdf:about="&dctermsns;created">
<rdfs:label>Created</rdfs:label>
<rdfs:comment>Date of creation of the resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;date"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;issued">
<rdfs:label>Issued</rdfs:label>
<rdfs:comment>Date of formal issuance (e.g., publication) of the
resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;date"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;modified">
<rdfs:label>Modified</rdfs:label>
<rdfs:comment>Date on which the resource was changed.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;date"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;valid">
<rdfs:label>Valid</rdfs:label>
<rdfs:comment>Date (often a range) of validity of a resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;date"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;available">
<rdfs:label>Available</rdfs:label>
<rdfs:comment>Date (often a range) that the resource will become or
did become available.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;date"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<!-- Encoding Schemes -->
<rdfs:Class rdf:about="&dctermsns;DateScheme">
<rdfs:label>Date Encoding Schemes</rdfs:label>
<rdfs:comment>A set of date encoding schemes and/or formats
</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;W3CDTF">
<rdfs:label>W3C-DTF</rdfs:label>
<rdfs:comment>
encoded with the W3C Encoding rules for dates and times - a profile based on ISO8601
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DateScheme"/>
<rdf:type rdf:resource="&dctermsns;TemporalScheme"/>
<rdfs:seeAlso rdf:resource="http://www.w3.org/TR/NOTE-datetime"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;Period">
<rdfs:label>DCMI Period</rdfs:label>
<rdfs:comment>A specification of the limits of a time interval.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DateScheme"/>
<rdf:type rdf:resource="&dctermsns;TemporalScheme"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-period/"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<!-- End: Date -->
<!-- Begin: format -->
<!-- format refinement declarations -->
<rdf:Property rdf:about="&dctermsns;extent">
<rdfs:label>Extent</rdfs:label>
<rdfs:comment>The size or duration of the resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;format"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;medium">
<rdfs:label>Medium</rdfs:label>
<rdfs:comment>The material or physical carrier of the resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;format"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<!-- Encoding Scheme declarations -->
<rdfs:Class rdf:about="&dctermsns;FormatScheme">
<rdfs:label>Format Encoding Schemes</rdfs:label>
<rdfs:comment>A set of format encoding schemes.</rdfs:comment>
<rdfs:isDefinedBy rdf:resource ="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;IMT">
<rdfs:label>IMT</rdfs:label>
<rdfs:comment>The Internet media type of the resource.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;FormatScheme"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
<rdfs:seeAlso
rdf:resource="http://www.isi.edu/in-notes/iana/assignments/media-types/media-types"/>
</rdfs:Class>
<!-- End: format -->
<!-- Begin: Language -->
<!-- Language refinement declarations -->
<!-- Encoding Scheme declarations -->
<rdfs:Class rdf:about="&dctermsns;LanguageScheme">
<rdfs:label>Language Encoding Schemes</rdfs:label>
<rdfs:comment>A set of language encoding schemes and/or formats.
</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;RFC1766">
<rdfs:label>RFC1766</rdfs:label>
<rdfs:comment>Internet RFC 1766 'Tags for the identification of
Language' specifies a two letter code taken from ISO 639, followed
optionally by a two letter country code taken from ISO 3166.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;LanguageScheme"/>
<rdfs:seeAlso rdf:resource="http://www.ietf.org/rfc/rfc1766.txt"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;ISO639-2">
<rdfs:label>ISO 639-2</rdfs:label>
<rdfs:comment>ISO 639-2: Codes for the representation of names of
languages.</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;LanguageScheme"/>
<rdfs:seeAlso
rdf:resource="http://www.loc.gov/standards/iso639-2/langhome.html"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<!-- End: language -->
<!-- Begin: Relation -->
<!-- Relation refinement declarations -->
<rdf:Property rdf:about="&dctermsns;isPartOf">
<rdfs:label>Is Part Of</rdfs:label>
<rdfs:comment>The described resource is a physical or logical part
of the referenced resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;hasPart">
<rdfs:label>Has Part</rdfs:label>
<rdfs:comment>The described resource includes the referenced resource
either physically or logically.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;isVersionOf">
<rdfs:label>Is Version Of</rdfs:label>
<rdfs:comment>The described resource is a version, edition, or
adaptation of the referenced resource. Changes in version imply
substantive changes in content rather than differences in format.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;hasVersion">
<rdfs:label>Has Version</rdfs:label>
<rdfs:comment>The described resource has a version, edition, or
adaptation, namely, the referenced resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;isFormatOf">
<rdfs:label>Is Format Of</rdfs:label>
<rdfs:comment>The described resource is the same intellectual content
of the referenced resource, but presented in another format.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;hasFormat">
<rdfs:label>Has Format</rdfs:label>
<rdfs:comment>The described resource pre-existed the referenced
resource, which is essentially the same intellectual content presented
in another format.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;references">
<rdfs:label>References</rdfs:label>
<rdfs:comment>The described resource references, cites, or otherwise
points to the referenced resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;isReferencedBy">
<rdfs:label>Is Referenced By</rdfs:label>
<rdfs:comment>The described resource is referenced, cited, or
otherwise pointed to by the referenced resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;requires">
<rdfs:label>Requires</rdfs:label>
<rdfs:comment>The described resource requires the referenced resource
to support its function, delivery, or coherence of content.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;isRequiredBy">
<rdfs:label>Is Required By</rdfs:label>
<rdfs:comment>The described resource is required by the referenced
resource, either physically or logically. </rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;replaces">
<rdfs:label>Replaces</rdfs:label>
<rdfs:comment>The described resource supplants, displaces, or
supersedes the referenced resource.
</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;isReplacedBy">
<rdfs:label>Is Replaced By</rdfs:label>
<rdfs:comment>The described resource is supplanted, displaced, or
superseded by the referenced resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Description rdf:about="&rdfsns;seeAlso">
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
</rdf:Description>
<rdf:Description rdf:about="&rdfsns;isDefinedBy">
<rdfs:subPropertyOf rdf:resource="&dcns;relation"/>
</rdf:Description>
<!-- Encoding Scheme declarations -->
<!-- End: Relation -->
<!-- Begin: coverage -->
<!-- Coverage refinement declarations -->
<rdf:Property rdf:about="&dctermsns;spatial">
<rdfs:label>Spatial</rdfs:label>
<rdfs:comment>Spatial characteristics of the intellectual content of
the resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;coverage"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<rdf:Property rdf:about="&dctermsns;temporal">
<rdfs:label>Temporal</rdfs:label>
<rdfs:comment>Temporal characteristics of the intellectual content
of the resource.</rdfs:comment>
<rdfs:subPropertyOf rdf:resource="&dcns;coverage"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdf:Property>
<!-- Coverage range declarations -->
<!-- Encoding Schemes -->
<rdfs:Class rdf:about="&dctermsns;SpatialScheme">
<rdfs:label>Place Encoding Schemes</rdfs:label>
<rdfs:comment>A set of geographic place encoding schemes and/or
formats</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;TGN">
<rdfs:label>TGN</rdfs:label>
<rdfs:comment>The Getty Thesaurus of Geographic Names
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SpatialScheme"/>
<rdfs:seeAlso
rdf:resource="http://www.getty.edu/research/tools/vocabulary/tgn/"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;" />
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;ISO3166">
<rdfs:label>ISO3166</rdfs:label>
<rdfs:comment>ISO3166 Codes for the representation of names of
countries</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SpatialScheme" />
<rdfs:seeAlso
rdf:resource="http://www.din.de/gremien/nas/nabd/iso3166ma/codlstp1/"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;Box">
<rdfs:label>DCMI Box</rdfs:label>
<rdfs:comment>The DCMI Box encoding scheme is a method for identifying
a region of space using its geographic limits.</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SpatialScheme"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-box/"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;Point">
<rdfs:label>DCMI Point</rdfs:label>
<rdfs:comment>DCMI Point is used for identifying a point in space
using its geographic coordinates</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;SpatialScheme"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-point/"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;TemporalScheme">
<rdfs:label>Encoding Schemes for temporal characteristics
of the intellectual content of a resource</rdfs:label>
<rdfs:comment>A set of encoding schemes and/or
formats for temporal characteristics of the intellectual
content of a resource</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<!-- End: coverage -->
<!-- Begin: type -->
<!-- Encoding Schemes -->
<rdfs:Class rdf:about="&dctermsns;TypeScheme">
<rdfs:label>Resource Type Encoding Schemes</rdfs:label>
<rdfs:comment>A set of resource type encoding schemes and/or
formats</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctermsns;DCMIType">
<rdfs:label>DCMI Type Vocabulary</rdfs:label>
<rdfs:comment>A list of types used to categorize the nature or
genre of the content of the resource.</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;TypeScheme"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:seeAlso rdf:resource="&dctypens;"/>
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdf:Description rdf:about="&rdfns;type">
<rdfs:subPropertyOf rdf:resource="&dcns;type"/>
</rdf:Description>
<!-- End: type -->
</rdf:RDF>
5.2 DCMIType RDF Schema Draft
<?xml version="1.0"?>
<!--
RDF Schema declaration Draft for DCMI Type Vocabulary
This Version:
2002/05/15
(comments to DC Architecture WG,
http://www.jiscmail.ac.uk/lists/dc-architecture.html)
-->
<!DOCTYPE rdf:RDF [
<!ENTITY rdfns 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
<!ENTITY rdfsns 'http://www.w3.org/2000/01/rdf-schema#'>
<!ENTITY dcns 'http://purl.org/dc/elements/1.1/'>
<!ENTITY dctermsns 'http://purl.org/dc/terms/'>
<!ENTITY dctypens 'http://purl.org/dc/dcmitype/'>
]>
<rdf:RDF
xmlns:rdf="&rdfns;"
xmlns:rdfs="&rdfsns;"
xmlns:dc="&dcns;"
xmlns:dcterms="&dctermsns;"
xmlns:dctype="&dctypens;">
<!-- Description of this Schema -->
<rdf:Description rdf:about="&dctypens;">
<dc:title>The DCMI Types namespace providing access
to it's content by means of an RDF Schema</dc:title>
<dc:publisher>The Dublin Core Metadata Initiative</dc:publisher>
<dc:description>The Dublin Core Types namespace provides URIs for the
entries of the DCMI Type Vocabulary. Entries are declared using RDF Schema
language to support RDF applications.</dc:description>
<dc:language>English</dc:language>
<dcterms:requires rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<dc:source rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
</rdf:Description>
<rdfs:Class rdf:about="&dctermsns;DCMIType">
<dc:description>
The DCMI Type Vocabulary provides a general, cross-domain list of approved
terms that may be used as values for the Resource Type element to identify
the genre of a resource.
</dc:description>
<rdf:type rdf:resource="&dctermsns;TypeScheme" />
<rdfs:isDefinedBy rdf:resource="&dctermsns;"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Collection">
<rdfs:label>Collection</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
A collection is an aggregation of items. The term collection means that
the resource is described as a group; its parts may be separately
described and navigated.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Dataset">
<rdfs:label>Dataset</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
A dataset is information encoded in a defined structure (for example,
lists, tables, and databases), intended to be useful for direct
machine processing.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Event">
<rdfs:label>Event</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
An event is a non-persistent, time-based occurrence. Metadata for an
event provides descriptive information that is the basis for discovery
of the purpose, location, duration, responsible agents, and links to
related events and resources. The resource of type event may not be
retrievable if the described instantiation has expired or is yet to occur.
Examples - exhibition, web-cast, conference, workshop,day,
performance, battle, trial, wedding, tea-party, conflagration.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Image">
<rdfs:label>Image</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
An image is a primarily symbolic visual representation other than text.
For example - images and photographs of physical objects, paintings,
prints, drawings, other images and graphics, animations and moving
pictures, film, diagrams, maps, musical notation. Note that image may
include both electronic and physical representations.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;InteractiveResource">
<rdfs:label>Interactive Resource</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
An interactive resource is a resource which requires interaction from the
user to be understood, executed, or experienced. For example - forms on web
pages, applets, multimedia learning objects, chat services, virtual reality.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Software">
<rdfs:label>Software</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
Software is a computer program in source or compiled form which may be
available for installation non-transiently on another machine. For
software which exists only to create an interactive environment, use
interactive instead.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Service">
<rdfs:label>Service</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
A service is a system that provides one or more functions of value to the
end-user. Examples include: a photocopying service, a banking service,
an authentication service, interlibrary loans, a Z39.50 or Web server.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Sound">
<rdfs:label>Sound</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
A sound is a resource whose content is primarily intended to be rendered
as audio. For example - a music playback file format, an audio compact
disc, and recorded speech or sounds.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
<rdfs:Class rdf:about="&dctypens;Text">
<rdfs:label>Text</rdfs:label>
<rdfs:isDefinedBy rdf:resource="&dctypens;"/>
<rdfs:seeAlso
rdf:resource="http://dublincore.org/documents/dcmi-type-vocabulary/"/>
<rdfs:comment>
A text is a resource whose content is primarily words for reading.
For example - books, letters, dissertations, poems, newspapers, articles,
archives of mailing lists. Note that facsimiles or images of texts are still
of the genre text.
</rdfs:comment>
<rdf:type rdf:resource="&dctermsns;DCMIType"/>
</rdfs:Class>
</rdf:RDF>
6 Appendix: Summary DC QualifiersThis is a convenience copy. The normative reference is [DCQual].
7 AcknowledgementsThe authors wish to thank Tom Baker, Dan Brickley, Tim Cole, Makx Dekkers, Carl Lagoze, Sigfrid Lundberg, Eric Miller, Tod Matola, Judith Plümer, Hartmut Polzer, Harry Wagner and Stu Weibel for helpful and stimulating contributions. Particular thanks to Aaron Swartz for his suggestions and contributions to the DumbDown algorithm and bug reports and to the contributors of the Namespace Policy for the Dublin Core Metadata Initiative (DCMI) , which provided the necessary namespace normalization. Thanks to the DC Architecture Working Group for its patience. Most of the techniques proposed here have their basis in [DM],[RDFMS] and [RDFS]. The scheme proposals are essentially due to Eric Miller. Thanks to Dave Beckett for his constructive suggestions for the final version. 8 References8.1 Required
8.2 Informational
Roland
Schwänzl The authors wish to thank the BMBF (SFM CARMEN) for partial support during the preparation of this document.
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