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| author | Sebastian Trueg <trueg@kde.org> | 2009-11-30 19:16:03 +0000 |
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| committer | Sebastian Trueg <trueg@kde.org> | 2009-11-30 19:16:03 +0000 |
| commit | 97ed16d3dc30e537baf7a2984c8fff3535dfc32e (patch) | |
| tree | 287d99810798324d308cec50dde553f9e98ab69c /nao | |
| parent | 12cec34c5c50eb50fe551b725eaa36d62f3b0239 (diff) | |
Moved the docs out of the ontologies tree for two reasons: 1. we do not use them yet and 2. I will add a svn:external to kdesupport and nobody wants to download the tons of MBs that are the docs.
Diffstat (limited to 'nao')
| -rw-r--r-- | nao/doc/nao-header.html | 3466 |
1 files changed, 0 insertions, 3466 deletions
diff --git a/nao/doc/nao-header.html b/nao/doc/nao-header.html deleted file mode 100644 index d4694cc..0000000 --- a/nao/doc/nao-header.html +++ /dev/null @@ -1,3466 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html style="direction: ltr;" xmlns="http://www.w3.org/1999/xhtml" lang="en-us"> -<head> - - - - - - - - - - - - <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> - - - - - - - - - - - - <link rel="stylesheet" type="text/css" href="nepomuk-ontology-docs.css" /> - - - - - - - - - - - - - - - - - - <title>NEPOMUK Annotation Ontology (NAO)</title> - <meta content="Simon Scerri" name="author" /> - - - - - - - - - - - - <meta content="Specifications for the NEPOMUK Annotation Ontology, including Graph Metadata Vocabulary" name="description" /> -</head> - - -<body> - - - - - - -<div class="head"> -<div class="nav"> <a href="http://nepomuk.semanticdesktop.org"> <img src="nepomuk1.png" /></a><a href="http://nepomuk.semanticdesktop.org/"><img style="border: 0px solid ; width: 180px; height: 88px;" alt="NEPOMUK Logo" src="nepomuk.png" /></a></div> - - - - - - -<h1>NEPOMUK Annotation Ontology Specification</h1> - - - - - - -<big style="color: rgb(0, 90, 156);">Task-Force Ontologies</big> -<dl> - - - - - - - <dt>Latest Version:</dt> - - - - - - - <dd><a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nao">http://www.semanticdesktop.org/ontologies/nao</a></dd> - - - - - - - <dt></dt> - - - - - - - <dt>This Version:</dt> - - - - - - - <dd><a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nao">http://www.semanticdesktop.org/ontologies/2007/08/15/nao</a></dd> - - - - - - -</dl> - - - - - - -<dl> - - - - - - - <dt>Authors:</dt> - - - - - - - <dd>Simon Scerri, DERI/NUIG, <a href="mailto:simon.scerri@deri.org">simon.scerri@deri.org</a></dd> - - - - - - - <dd>Michael Sintek, DFKI, <a href="mailto:michael.sintek@dfki.de">michael.sintek@dfki.de</a></dd> - - - - - - - <dd>Ludger van Elst, DFKI, <a href="mailto:elst@dfki.uni-kl.de">elst@dfki.uni-kl.de</a></dd> - - - - - - - <dd>Siegfried Handschuh, DERI/NUIG, <a href="siegfried.handschuh@deri.org">siegfried.handschuh@deri.org</a></dd> - - - - - - -</dl> - - - - - - -<span style="font-weight: bold;">Editor:</span> <br /> - - - - - - -<div style="margin-left: 40px;">Simon Scerri, DERI/NUIG, <a href="mailto:simon.scerri@deri.org">simon.scerri@deri.org</a> -</div> - - - - - - -<dl> - - - - - - - <dt>Contributors:</dt> - - - - - - - <dd>Leo Sauermann, DFKI, <a href="mailto:leo.sauermann@dfki.de">leo.sauermann@dfki.de</a></dd> - - - - - - - <dd>Max Völkel, FZI, <a href="mailto:voelkel@fzi.de">voelkel@fzi.de</a></dd> - - - - - - - <dd>Sebastian Trüg, EDGE-IT, <span class="wikiexternallink"><a href="mailto:strueg@mandriva.com">strueg@mandriva.com</a></span></dd> - - - - - - - <dd>Knud Möller, DERI/NUIG, <a href="mailto:knud.moeller@deri.org">knud.moeller@deri.org</a></dd> - - - - - - - <dd>Julien Gaugaz, L3S, <a href="mailto:gaugaz@l3s.de">gaugaz@l3s.de</a> </dd> - - - - - - - <dd>Antoni Mylka, DFKI, <a href="mailto:antoni.mylka@dfki.de">antoni.mylka@dfki.de</a> <br /> - - - - - - - </dd> - - - - - - -</dl> - - - - - - -<dl> - - - - - - - <dt><span style="font-weight: bold;">Ontology:</span></dt> - - - - - - - <dd>XML/RDFS Serialization: <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nao/nao_data.rdfs">NAO -(Data Graph Only)</a></dd> - - - - - - - <dd>XML/RDFS Serialization: <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nao/nao_metadata.rdfs">NAO -(Metadata Graph Only)</a></dd> - - - - - - - <dd>TriG Serialization: <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nao/nao.trig">NAO -(Graph Set)</a><span class="wikiexternallink"></span></dd> - - - - - - -</dl> - - - - - - -<dl> - - - - - - - <dd></dd> - - - - - - -</dl> - - - - - - -</div> - - - - - - -<p class="copyright"> Copyright © 2007 <a href="http://nepomuk.semanticdesktop.org/">NEPOMUK Consortium</a><sup>®</sup> -This work is made available under the terms of NEPOMUK <a href="LICENSE.txt">software license</a> -</p> - - - - - - -<hr /> -<h2><a class="mozTocH2" name="mozTocId474323"></a>Abstract</h2> - - - - - - -<p style="text-align: justify;">The annotation ontology -provides -vocabulary that enables users to attach custom descriptions, -identifiers, tags and ratings to resources on their desktop. Via other -properties, the user is also able to make generic relationships between -related resources explicit. Some relationships between resources are -too general to be included at the domain ontology level. Instead, these -properties are also defined in the annotation ontology. Given the -high-level status of this ontology, these propreties can be -used -to link any related resources on the user's desktop, as well -as -provide custom human-readable textual annotations.</p> - - - - - - -<h2><a class="mozTocH2" name="mozTocId596458"></a>Status -of this document</h2> - - - - - - -<div id="sotd"> -<p style="text-align: justify;"> This document arose from -the work of the Task-Force ontologies within the [<a href="http://nepomuk.semanticdesktop.org/">NEPOMUK Project</a>]. -It presents the specifications for the first version of the NAO -vocabulary. The ontology is still being tested, which means that the -ontology and this specification document are prone to -change. The -document itself is pending a review by the general NEPOMUK consortium, -upon which it might be promoted from a draft to an official form. -Subsequent versions of NAO might mean that the specification documents -of the later versions render this document obsolete, with respect to -the version of NAO in use, but not with respect to this version. </p> - - - - - - -</div> - - - - - - -<div class="toc"> -<h2 id="contents"><a class="mozTocH2" name="mozTocId577732"></a>Contents</h2> - - - - - - -</div> - - - - - - -<div> -<ul id="mozToc"> - - - - -<!--mozToc h2 1 h3 2 h4 3 h5 4--><li><a href="#mozTocId474323">Abstract</a></li> - - - - - <li><a href="#mozTocId596458">Status -of this document</a></li> - - - - - <li><a href="#mozTocId577732">Contents</a></li> - - - - - <li><a href="#mozTocId738538">1. Introduction</a></li> - - - - - <li><a href="#mozTocId127057">2. Generic -Annotation Vocabulary</a> - - - - - <ul> - - - - - <li><a href="#mozTocId775195">2.1. -Basic Annotation</a> - - - - - <ul> - - - - - <li><a href="#mozTocId991277">2.1.1. nao:annotation - - </a></li> - - - - - <li><a href="#mozTocId95916">2.1.2. rdfs:label - - </a></li> - - - - - <li><a href="#mozTocId231785">2.1.3. rdfs:comment - - </a></li> - - - - - <li><a href="#mozTocId827817">2.1.4. nao:hasSymbol - - </a></li> - - - - - <li><a href="#mozTocId309849">2.1.5. nao:rating - - </a></li> - - - - - <li><a href="#mozTocId802441">2.1.6. nao:identifier - - </a></li> - - - - - <li><a href="#mozTocId554293">2.1.7. nao:Symbol - - </a></li> - - - - - <li><a href="#mozTocId323566">2.1.8. nao:Tag - - </a></li> - - - - - <li><a href="#mozTocId540464">2.1.9. nao:Party - - </a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId187157">2.2. More -Specific Annotation</a> - - - - - <ul> - - - - - <li><a href="#mozTocId17438">2.2.1. nao:isRelated - - </a></li> - - - - - <li><a href="#mozTocId953268">2.2.2. nao:hasTopic - - </a></li> - - - - - <li><a href="#mozTocId682683">2.2.3. nao:isTopicOf - - </a></li> - - - - - <li><a href="#mozTocId292538">2.2.4. nao:hasTag</a></li> - - - - - <li><a href="#mozTocId891981">2.2.5. -nao:isTagFor</a></li> - - - - - <li><a href="#mozTocId460510">2.2.6. nao:prefLabel - - </a></li> - - - - - <li><a href="#mozTocId337732">2.2.7. nao:altLabel - - </a></li> - - - - - <li><a href="#mozTocId418437">2.2.8. -nao:pluralPrefLabel - - </a></li> - - - - - <li><a href="#mozTocId541375">2.2.9. nao:prefSymbol - - </a></li> - - - - - <li><a href="#mozTocId27440">2.2.10. nao:altSymbol</a></li> - - - - - <li><a href="#mozTocId845316">2.2.11. -nao:description - - </a></li> - - - - - <li><a href="#mozTocId591601">2.2.12. -nao:personalIdentifier - - </a></li> - - - - - <li><a href="#mozTocId4771">2.2.13. -nao:numericRating</a></li> - - - - - <li><a href="#mozTocId430224">2.2.14. nao:creator</a></li> - - - - - <li><a href="#mozTocId321643">2.2.15. -nao:contributor</a></li> - - - - - <li><a href="#mozTocId287675">2.2.16. nao:modified</a></li> - - - - - <li><a href="#mozTocId288437">2.2.17. nao:created</a></li> - - - - - <li><a href="#mozTocId412121">2.2.18. -nao:lastModified</a></li> - - - - - <li><a href="#mozTocId601106">2.2.19. -nao:score</a></li> - - - - - <li><a href="#mozTocId105820">2.2.20. -nao:scoreParameter</a></li> - - - - - <li><a href="#mozTocId400559">2.2.21. -nao:FreeDesktopIcon</a></li> - - - - - <li><a href="#mozTocId232585">2.2.22. -nao:iconName</a></li> - - - - - <li><a href="#mozTocId880189">2.2.23. -nao:hasSubResource</a></li> - - - - - <li><a href="#mozTocId693750">2.2.24. -nao:hasSuperResource</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId620976">2.3. -Tagging as Annotation - - </a></li> - - - - - <li><a href="#mozTocId873837">2.4. -Generic Annotation Example</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId836701">3. Graph -Metadata Vocabulary</a> - - - - - <ul> - - - - - <li><a href="#mozTocId215877">3.1 -General Graph Metadata</a> - - - - - <ul> - - - - - <li><a href="#mozTocId925972">3.1.4. -nao:hasDefaultNamespace</a></li> - - - - - <li><a href="#mozTocId505129">3.1.5. -nao:hasDefaultNamespaceAbbreviation</a></li> - - - - - <li><a href="#mozTocId297228">3.1.6. -nao:engineeringTool - - </a></li> - - - - - <li><a href="#mozTocId652689">3.1.7. nao:version</a></li> - - - - - <li><a href="#mozTocId642918">3.1.8. nao:status</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId370287">3.2. Document -Graph Metadata</a> - - - - - <ul> - - - - - <li><a href="#mozTocId89753">3.3.1. -nao:serializationLanguage</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId785190">3.3. Graph -Metadata Example</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - - <li><a href="#mozTocId760420">References</a></li> - - - - - <li><a href="#mozTocId78171">Appendix -A. NAO Vocabulary Summary - - </a> - - - - - <ul> - - - - - <li><a href="#mozTocId177728">A1: -Ontology Classes Description</a></li> - - - - - <li><a href="#mozTocId918756">A2: -Ontology Properties Description</a></li> - - - - - - - - - </ul> - - - - - </li> - - - - -</ul> - - - - - - -<hr style="width: 100%; height: 2px;" /> -<h1>NAO Vocabulary Specification</h1> - - - - - - -<p style="text-align: justify;">This document presents the -specifications for the NEPOMUK Annotation Ontology, a vocabulary for -resource annotation that is based on the NEPOMUK Representational -Language [<a href="#References">NRL SPECIFICATION</a>]. -The ontology is available for general and individual use and -is independent of the domain for which it was initially designed for, -namely the [<a href="http://nepomuk.semanticdesktop.org/">NEPOMUK -Social Semantic Desktop</a>] initiative. The -NEPOMUK in -the ontology name (NAO) has been -retained only for historic purposes. </p> - - - - - - -<p style="text-align: justify;">The document is -structured as follows. -Section 1 provides an insight of what we consider to be annotation -within the context of NRL and the social semantic desktop. Section 2 -introduces vocabulary for generic annotation, i.e. general annotation -of resources, with a particular emphasis on how conventional tagging -can also be represented using this ontology. Section 3 introduces -vocabulary that supports annotation for graphs, or graph metadata. -Given the important role that named graphs have in NRL, -annotation for graphs is also consideted part of this -ontology. Finallya summary of all the NAO -vocabulary elements is given in [ <a href="#Appendix_A._NAO_Vocabulary_Summary">Appendix A</a>]. -</p> - - - - - - -<h2><a class="mozTocH2" name="mozTocId738538"></a><a name="1._Introduction"></a>1. Introduction</h2> - - - - - - -<div style="text-align: justify;"> -<p>The meaning of the term annotation is highly contextual. -Depending -on the context, anything or nothing can be considered as annotation -within a data set (or named graph). On the social semantic -desktop, the average user is frequently seen creating representations -of objects on their desktop, while the more experienced user is also -frequently creating representations of concepts and their -relationships. Sharing and creating relationships between all -these resources across multiple desktops is what makes a user's desktop -social and semantic. Within this context, we consider annotation to be -anything that goes further than creating resources and -defining -their elementary relationships. A user can create an instance of a -'Person', and provide values for all the elementary properties that an -instance of 'Person' can have. The user can then go one step ahead and -annotate the resources with more information, of a textual (e.g. custom -human-readable descriptions) or non-textual (e.g. links to related -resources) -nature. In a typical scenario there may be a -number of domain-centric properties for the classes 'Person' (e.g. -name, address, knows etc.) and 'Document' (e.g. author, title etc.). -Via vocabulary in the annotation ontology the user can provide -personalized, user-friendly labels and descriptions for a resource, as -well as other things like tags and ratings. Generic -relationships may exist between resources across multiple domains, and -making these relationships explicit would be of great benefit for the -user. For example, a user wants to state that a -'Document' is about some instance of 'Person'. This relationship is too -general to be applied at the domain -ontology level, since such a relationship may exist between -other concepts in other domains e.g. between 'Conference' and -'Technology'. Vocabulary that is able to express these generic -relationships are therefore provided by the annotation -ontology. Although this information is optional and does not reflect -the elementary nature of a 'Document', it contributes to -improved -data unification and eases user search. </p> - - - - - - -<p style="text-align: justify;">We model annotation via -properties, rather than classes, since -we -believe that annotation is a relationship and not a concept. This was -also the idea for the rdfs:label and rdfs:comment properties in the -RDFS vocabulary, which we consider as textual annotation. These -properties are in fact included in our specifications, especially since -in the context of this ontology and that of the social semantic desktop -they have a slightly different meaning. Generic annotation is -represented at its highest level with the abstract nao:annotation -property. Although it is not meant to be used, it is the superproperty -of many other annotation properties in this ontology. Vocabulary for -generic annotation is introduced in <a href="#2._Generic_Annotation_Vocabulary">Section 2</a>.</p> - - - - - - -<p style="text-align: justify;">Graph Metadata is also a -form of annotation, where instead -of annotating general resources, one annotates Named -Graphs. Therefore graph metadata properties can be modelled -under the general annotation property <a href="#2.1.1._nao:annotation">nao:annotation</a>, -where the resource being annotated is a graph role (instance -of nrl:Data) and the annotations are provided via the graph metadata -properties. The major difference is -that while generic annotation can be stored within any graph the user -is working with (e.g. the graph where the annotated resource is -defined), -metadata about a graph should always be stored outside that -graph, -in a separate special named graph that is aptly represented in NRL -by <span style="background-color: rgb(255, 255, 255);">[<a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.7._nrl:GraphMetadata">nrl:GraphMetadata</a>]. -Graph Metadat Vocabulary is introduced in <a href="#3._Graph_Metadata_Vocabulary">Section 3</a>. -</span></p> - - - - - - -</div> - - - - - - -<span style="background-color: rgb(255, 255, 0);"></span> -<h2 style="text-align: justify;"><a class="mozTocH2" name="mozTocId127057"></a><a name="2._Generic_Annotation_Vocabulary"></a>2. Generic -Annotation Vocabulary</h2> - - - - - - -<p style="text-align: justify;">In this section we -introduce vocabulary that serves generic annotation, i.e., -vocabulary that models general, common relationships between things. <a href="#2.1._Basic_Annotation">Section 2.1</a> presents -the basic annotation vocabulary. All other vocabulary in the annotation -ontology will require or derive from these basic terms. <a href="#2.2._More_Specific_Annotation">Section 2.2</a> -introduces richer annotation relationships that derive from the basic -annotation properties presented in Section 2.1. In <a href="#2.3._Tagging_as_Annotation">Section 2.3</a> we -discuss how we also model tagging as a form of annotation and finally -in <a href="#2.4._Generic_Annotation_Example">Section 2.4</a> -we present a concise example of how the vocabulary presented in this -section can be employed.<br /> - - - - - - -</p> - - - - - - -<h3><a class="mozTocH3" name="mozTocId775195"></a><a name="2.1._Basic_Annotation"></a>2.1. -Basic Annotation</h3> - - - - - - -<p style="text-align: justify;">The most basic annotation -property is nao:annotation, which simply defines a -descriptive -property for a resource. Given that an annotation's nature can be -textual or non-textual (i.e. semantic annotation pointing to -a resource), the range of this abstract high-level property is left -undefined. Specific subproperties -can have richer semantics (e.g. symmetric properties), but in order to -abstract over all annotation properties, no such semantics are defined -for <a href="#2.1.1._nao:annotation">nao:annotation</a>. </p> - - - - - - -<p style="text-align: justify;">rdfs:label and -rdfs:comment are also (indirectly) considered as part of our annotation -ontology, as they provide textual annotations for a resource. Although -we do not define them as being subproperties of -nao:annotation, we also include them in these specifications, in order -to define their meaning in the context of the social semantic -desktop. </p> - - - - - - -<p style="text-align: justify;">These and other annotation -properties and required classes are specified below. The annotation -properties defined in this section are also illustrated in <a href="#Fig_1">Fig.1</a>.<br /> - - - - - - -</p> - - - - - - -<div style="text-align: center;"><img src="basic.png" alt="basic" style="width: 425px; height: 173px;" /><br /> - - - - - - -<a name="Fig_1"></a> -Figure1. Basic annotation properties<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId991277"></a><a name="2.1.1._nao:annotation"></a>2.1.1. nao:annotation<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">An abstract property -representing a -general annotation for a resource. Given its abstract nature -and its undefined range, this property is not meant to be used directly.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId95916"></a><a name="2.1.2._rdfs:label"></a>2.1.2. rdfs:label<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">We consider this RDFS -property as part of our annotation -ontology, since it provides a textual annotation which relates a -resource to -a literal. In the context of the social semantic desktop this property -provides technical labels for a resource, i.e, a -non-user -customizable label that is not meant to be seen by the user. -User-customizable labels are possible via the use of our own -sub-properties <a href="#2.2.6._nao:prefLabel">nao:prefLabel</a> -and <a href="#2.2.7._nao:altLabel">nao:altLabel</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId231785"></a><a name="2.1.3._rdfs:comment"></a>2.1.3. rdfs:comment<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This RDFS property is also -considered as part of our -annotation ontology, -since it provides a textual annotation which relates a resource to -a literal. -In the context of the social semantic desktop, this property -provides technical descriptions for a -resource. Non-technical, custom user descriptions can be -provided by our own subproperty, <a href="#2.2.11._nao:description">nao:description</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId827817"></a><a name="2.1.4._nao:hasSymbol"></a>2.1.4. nao:hasSymbol<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">A resource can be -annotated with an instance of <a href="#2.1.7._nao:Symbol">nao:Symbol</a> -via -subproperties of this abstract property, <a href="#2.2.9._nao:prefSymbol">nao:prefSymbol</a> and <a href="#2.2.10._nao:altSymbol">nao:altSymbol</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId309849"></a><a name="2.1.5._nao:rating"></a>2.1.5. nao:rating<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">Users can rate a resource -via subproperties of this property, -which is not meant to be used directly. Specific subproperties can -extend it and be used to rate resources, e.g. an audio file. -The range of this property is undefined. Numeric ratings can be -assigned via <a href="#2.2.13._nao:numericRating">nao:numericRating</a> -(maximum cardinality 1). -If other kinds of ratings are needed, this property can -arbitrarily and easily extend be extended (e.g. with a property that -has as range a class for which a number of instances can be enumerated).</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId802441"></a><a name="2.1.6._nao:identifier"></a>2.1.6. nao:identifier<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This property enables -further types of identifiers for a -resource, apart from its standard URI. The property itself -is not meant to be directly used since it is an abstract property and -does not have a defined range. The annotation ontology -provides a subproperty for this property, <a href="#2.2.12._nao:personalIdentifier">nao:personalIdentifier</a>. - Although this property is not applied any form of -restriction, all its subproperties, including <a href="#2.2.12._nao:personalIdentifier">nao:personalIdentifier</a>, -are meant to be inverse functional. <span style="font-weight: bold;"></span></p> - - - - - - -<div style="text-align: center;"> -<div style="text-align: left;"> -<h4><a class="mozTocH4" name="mozTocId554293"></a><a name="2.1.7._nao:Symbol"></a>2.1.7. nao:Symbol<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This -class represents a symbol, which can be an icon -or an image for example, that is used to annotate a resource. -Resources can be annotated with a standard graphical symbol via the -subproperties of <a href="#2.1.4._nao:hasSymbol">nao:hasSymbol</a>, <a href="#2.2.9._nao:prefSymbol">nao:prefSymbol</a> and <a href="#2.2.10._nao:altSymbol">nao:altSymbol</a>. Any -such graphical symbol that is in this way used to annotate a resource -automatically becomes an instance of this class.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId323566"></a><a name="2.1.8._nao:Tag"></a>2.1.8. <span style="background-color: rgb(255, 255, 0);"></span>nao:Tag<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This class is useful for -modelling conventional tagging practices. The user can tag resources in -conventional ways, automatically creating an instance of this tag, -which is then related to the annotated resource via the <a href="#2.2.4._nao:hasTag">nao:hasTag</a> property. For -more on tagging as annotation see <a href="#2.3._Tagging_as_Annotation">Section 2.3</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId540464"></a><a name="2.1.9._nao:Party"></a>2.1.9. nao:Party<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;"><span style="background-color: rgb(255, 255, 255);">Annotations -are provided by an individual or a group of individuals. Some -annotations are contained in a separate named graph whose role is to -provide annotations about another named graph (e.g. graph metadata for -a graph, See <a href="#3._Graph_Metadata_Vocabulary">Graph -Metadata Vocabulary</a>). In such cases it is useful to -state the contributor(s) for the set of annotations. This -class -is provided to represent a party who created such a set of annotations, -where a party can be either one individual or a group of individuals -(e.g. an organization). Once a user or an group provides these -annotations, they automatically become an instance of this -class. </span></p> - - - - - - -</div> - - - - - - -</div> - - - - - - -<h3><a class="mozTocH3" name="mozTocId187157"></a><a name="2.2._More_Specific_Annotation"></a>2.2. More -Specific Annotation</h3> - - - - - - -<p style="text-align: justify;">The Annotation Ontology -provides more specific vocabulary that -extends the description power of the basic annotation vocabulary -presented in -the previous section. Vocabulary in this category consists -solely of properties which extend properties given in <a href="#2.1._Basic_Annotation">Section 2.1</a>. An -overview of these properties is illustrated in <a href="#Fig_2">Fig.2</a>. The -specifications for this vocabulary are given below. </p> - - - - - - -<span style="font-weight: bold;"></span> -<div style="text-align: center;"><img style="width: 664px; height: 271px;" alt="lower level properties" src="lowerLevel.png" /><br /> - - - - - - -<a name="Fig_2"></a> -Figure 2. More specific annotation properties<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId17438"></a><a name="2.2.1._nao:isRelated"></a>2.2.1. nao:isRelated<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This property defines a -symmetric relation between any two resources. A subproperty of -<a href="#2.1.1._nao:annotation">nao:annotation</a>, -one can use this property to annotate a resource with pointers -to related resources. For example, a blog entry for an event -may -be linked to an image of the same event via this property. In -order for this property to be used legally, the relationship must be -symmetric. </p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId953268"></a><a name="2.2.2._nao:hasTopic"></a>2.2.2. nao:hasTopic<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">A subproperty of <a href="#2.2.1._nao:isRelated">nao:isRelated</a>, -this property does not inherit its symmetric nature. It further defines -the relationship given by its superproperty, stating that a resource is -about some concept. Instead, this vocabulary provides an inverse -property for this property, <a href="#2.2.3._nao:isTopicOf">nao:isTopicOf</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId682683"></a><a name="2.2.3._nao:isTopicOf"></a>2.2.3. nao:isTopicOf<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This property is also a -subproperty of <a href="#2.2.1._nao:isRelated">nao:isRelated</a> -and is the inverse property of <a href="#2.2.2._nao:hasTopic">nao:hasTopic</a>. -It is used to create a relationship between two resources, where the -subject resource is said to be the topic of the object. It is -not -a symmetric property.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId292538"></a><a name="2.2.4._nao:hasTag"></a>2.2.4. nao:hasTag</h4> - - - - - - -<p style="text-align: justify;">Used to model conventional -tagging practices, this property annotates a resource with a tag, -represented by an instance of <a href="#2.1.8._nao:Tag">nao:Tag</a>. -For -more on tagging as annotation see <a href="#2.3._Tagging_as_Annotation">Section 2.3</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId891981"></a><a name="2.2.5._nao:isTagFor"></a>2.2.5. -nao:isTagFor</h4> - - - - - - -<p style="text-align: justify;">This property is the -inverse of <a href="#2.2.4._nao:hasTag">nao:hasTag</a>. -It links an instance of <a href="#2.1.8._nao:Tag">nao:Tag</a> -to resources that are tagged with it. For more on tagging as annotation -see <a href="#2.3._Tagging_as_Annotation">Section 2.3</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId460510"></a><a name="2.2.6._nao:prefLabel"></a>2.2.6. nao:prefLabel<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This property is one of -two provided by this ontology to handle -custom user labels. Alternative -labels can be provided via <a href="#2.2.7._nao:altLabel">nao:altLabel</a>. -Both properties are subproperties of <a href="#2.1.2._rdfs:label">rdfs:labe</a>l -and expect a -literal as value. Given that the domain of this property is -rdfs:Resource, it is not applied -any cardinality restrictions. Where required, such -properties -can be defined by extending this property via appropriate -subproperties. However, it is intended that at most one -value per (natural) language is defined via this property and -that at most one literal without any -defined language exists. Other usages, although legal, are considered -invalid NAO data and are strongly discouraged as -they may generate errors.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId337732"></a><a name="2.2.7._nao:altLabel"></a>2.2.7. nao:altLabel<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">Via this property a user -can provide further custom labels for -resources on their desktop, alongside the required, unique value given -by <a href="#2.2.6._nao:prefLabel">nao:prefLabel</a>. Both -properties are subproperties of <a href="#2.1.2._rdfs:label">rdfs:labe</a>l -and expect a literal as value.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId418437"></a><a name="2.2.8._nao:pluralPrefLabel"></a>2.2.8. -nao:pluralPrefLabel<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">This property supplements <a href="#2.2.6._nao:prefLabel">nao:prefLabel</a> -to provide plural forms for custom user resource labels. In particular -it is useful to refer to multiple instances of a calss. It is also a -subproperty of <a href="#2.1.2._rdfs:label">rdfs:labe</a>l -and expects a -literal as value. No cardinality restrictions are -imposed. -</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId541375"></a><a name="2.2.9._nao:prefSymbol"></a>2.2.9. nao:prefSymbol<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">A subproperty of <a href="#2.1.4._nao:hasSymbol">nao:hasSymbol</a>, this -property specifies a preferred symbol for resource annotation, given by -an instance of <a href="#2.1.7._nao:Symbol">nao:Symbol</a>. -Resources can be -annotated with alternative symbols via nao:altSymbol. </p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId27440"></a><a name="2.2.10._nao:altSymbol"></a>2.2.10. nao:altSymbol</h4> - - - - - - -<p style="text-align: justify;">This property is used to -annotate a resource with alternative symbols, given by instances -of <a href="#2.1.7._nao:Symbol">nao:Symbol</a>, -alongside the preferred symbol that is linked via <a href="#2.2.9._nao:prefSymbol">nao:prefSymbol</a>. It -is a subproperty of <a href="#2.1.4._nao:hasSymbol">nao:hasSymbol</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId845316"></a><a name="2.2.11._nao:description"></a>2.2.11. -nao:description<br /> - - - - - - -</h4> - - - - - - -<p style="text-align: justify;">A subproperty of <a href="#2.1.3._rdfs:comment">rdfs:comment</a>, the -purpose of this property is similar to <a href="#2.2.6._nao:prefLabel">nao:prefLabel</a> and <a href="#2.2.7._nao:altLabel">nao:altLabel</a>. However -this property is also a subproperty of <a href="#2.1.1._nao:annotation">nao:annotation</a>. -Whereas -in the context of the social semantic desktop the textual annotation -provided via <a href="#2.1.3._rdfs:comment">rdfs:comment</a> -is meant for technical users, the textual annotation here -is aimed -at average users and is meant to be used to define custom descriptions -of resources on their desktop. The maximum cardinality is 1, and the -property expects a literal value.<br /> - - - - - - -</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId591601"></a><a name="2.2.12._nao:personalIdentifier"></a>2.2.12. -nao:personalIdentifier<br /> - - - - - - -</h4> - - - - - - -<p>This property should be used to provide alternative values -that identify a -resource -alongside the default URI. A subproperty of the abstract <a href="#2.1.6._nao:identifier">nao:identifier</a>, -the range of this property is a literal. The property is inverse -functional, which effectively means that personal identifiers for -resources should be unique, and two resources cannot have the same -personal identifier.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId4771"></a><a name="2.2.13._nao:numericRating"></a>2.2.13. -nao:numericRating</h4> - - - - - - -<p>This property extends <a href="#2.1.5._nao:rating">nao:rating</a>, -to restrict the range to an XSD float datatype. Values must be between -'1' and '10' whereas a value of '0' is interpreted as not -set. Furthermore, -resources can only be given at most one numeric rating, thus the -maximum cardinality is 1. </p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId430224"></a><a name="2.2.14._nao:creator"></a>2.2.14. nao:creator</h4> - - - - - - -<div style="text-align: justify;"> -<p>Via this property the creator/s of a resource can be -specified graph. The creator -can be a an individual or a group as represented by an instance of the -<a href="#2.1.9._nao:Party">nao:Party</a> -class. </p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId321643"></a><a name="2.2.15._nao:contributor"></a>2.2.15. -nao:contributor</h4> - - - - - - -<p>This property -refers to additional contributors for a resource and is -otherwise similar to <a href="#2.2.14._nao:creator">nao:creator</a>.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId287675"></a><a name="2.2.16._nao:modified"></a>2.2.16. nao:modified</h4> - - - - - - -<p>Represents the modification date/time [<a href="http://www.w3.org/TR/xmlschema-2/#dateTime">xsd:dateTime</a>] -for a resource. More of an abstract class, its subproperties <a href="#2.2.17._nao:created">nao:created</a> and <a href="#2.2.18._nao:lastModified">nao:lastModified</a> -prove to be more useful.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId288437"></a><a name="2.2.17._nao:created"></a>2.2.17. nao:created</h4> - - - - - - -<p>Via this property the creation date/time for a resource can be -defined. A subproperty of nao:modified, the expected value is of -type [<a href="http://www.w3.org/TR/xmlschema-2/#dateTime">xsd:dateTime</a>] -and a typical value is of the form -"2007-08-15T23:59:55.329Z". The maximum cardinality for this property -is set to 1.</p> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId412121"></a><a name="2.2.18._nao:lastModified"></a>2.2.18. -nao:lastModified</h4> - - - - - - -<div style="text-align: justify;"> -<p>This property defines the date/time when a resource was most -recently modified. It is a subproperty of <a href="#2.2.16._nao:modified">nao:modified</a>. The -maximum cardinality -for this property is also set to 1.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId601106"></a><a name="2.2.19._nao:score"></a>2.2.19. -nao:score</h4> - - - - - - -<div style="text-align: justify;"> - - -<p>This property refers to an authorative score for an item -(resource), valued between [0, 1]. A score is a weight of a -resource compared to all other resources, and it is computed via a -mathematical combination of score -parameters e.g. nao:numericRating, -nao:lastModified as well external parameters. For this purpose, -parameters -that go into the score need to be marked as being sub-properties of <a href="#2.2.20._nao:scoreParameter">nao:scoreParameter</a>. Allowed values -for this property are of the [<a href="http://www.w3.org/TR/xmlschema-2/#float">xsd:float</a>] -datatype.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId105820"></a><a name="2.2.20._nao:scoreParameter"></a>2.2.20. -nao:scoreParameter</h4> - - - - - - -<p>Multiple score parameters -(e.g. nao:numericRating, -nao:lastModified) can be input to a mathematical -algorithm that -computes an overall <a href="#2.2.19._nao:score">nao:score</a> -for a resource. The score parameters in question need to be -defined as a subproperty of this property - thus effectively -nao:scoreParamter is a marker property. Ranking algorithms -will compute the values of multiple subproperties of scoreParameter and -then compute the nao:score based on a mathematical combination of score -parameters. The allowed range is a float number. The exact algorithm is -open to implementations. Allowed values for this property are -of the [<a href="http://www.w3.org/TR/xmlschema-2/#float">xsd:float</a>] -datatype.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId400559"></a><a name="2.2.21._nao:FreeDesktopIcon"></a>2.2.21. -nao:FreeDesktopIcon</h4> - - - - - - -<p>This class represents a desktop icon as defined -in the <a href="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">FreeDesktop -Icon Naming standard</a> and it is a subclass of <a href="#2.1.7._nao:Symbol">nao:Symbol</a>. <a href="#2.2.22._nao:iconName">nao:iconName</a> is a -required property referring to the name of the icon.</p> - - - - - - -<h4><a class="mozTocH4" name="mozTocId232585"></a><a name="2.2.22._nao:iconName"></a>2.2.22. -nao:iconName</h4> - - - - - - -<p>Values of this property contain the FreeDesktop standard icon -name (literal) as -defined in the <a href="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">FreeDesktop -Naming Specification</a>. The use of the property is required for -every instance of <a href="#2.2.21._nao:FreeDesktopIcon">nao:FreeDesktopIcon</a> -since its minimum cardinality is set to 1.</p> - - - - -<h4><a class="mozTocH4" name="mozTocId880189"></a><a name="2.2.23._nao:hasSubResource"></a>2.2.23. -nao:hasSubResource</h4> - - - - - - -<p>This property defines a super-sub relationship between two instances -of rdfs:Resource - whereby one resource can be treated as dependent on -another. Thus if a resource is deleted or removed from a system, all -its subresources can also be automatically removed, unless they have -other superresources still existant on the system. This property is the -inverse property of <a href="#2.2.24._nao:hasSuperResource">nao:hasSuperResource</a>. This property is transitive in nature. -</p> - - - - -<h4><a class="mozTocH4" name="mozTocId693750"></a><a name="2.2.24._nao:hasSuperResource"></a>2.2.24. -nao:hasSuperResource</h4> - - - - - - -<p>This property is the inverse of <a href="#2.2.23._nao:hasSubResource">nao:hasSubResource</a>. -It defines a dependency relationship between two resources such that, -when the superresource is removed from a system, the defined -subresources should also be removed unless they are also subresources -of other remaining superresources. This property is transitive in -nature.<span style="text-decoration: underline;"></span><br /> - - - - -</p> - - - - -<p> - -</p> - - - - - - -</div> - - - - - - -</div> - - - - - - -<h3><a class="mozTocH3" name="mozTocId620976"></a><a name="2.3._Tagging_as_Annotation"></a>2.3. -Tagging as Annotation<br /> - - - - - - -</h3> - - - - - - -<p style="text-align: justify;">Given tagging is a popular -Web 2.0 -concept which we want to adopt and retain in our semantic approach to -data modelling, in this section we provide an example of how semantic -tagging can be performed using our annotation ontology. <a href="#Fig_3">Fig.3</a> shows how -nao:Tag can -be used as a special case of the nao:annotation relation given in -<a href="#Fig_2">Fig.2</a>. The unique -default name given by the user when creating a -tag is defined by <a href="#2.2.6._nao:prefLabel">nao:prefLabel</a>. -Other custom names for the tag can be defined using <a href="#2.2.7._nao:altLabel">nao:altLabel</a> while a -custom user description can be provided via <a href="#2.2.11._nao:description">nao:description</a>. A -custom default icon or image can be attached to the tag via <a href="#2.2.9._nao:prefSymbol">nao:prefSymbol</a>, -making the icon in question an instance of <a href="#2.1.7._nao:Symbol">nao:Symbol</a>. -This icon, like any other resource, can also be annotated. The newly -created tag is then linked to the resource being tagged (or annotated) -via <a href="#2.2.4._nao:hasTag">nao:hasTag</a>. An -automatic inverse relationship is created to link the new tag with the -resource via <a href="#2.2.5._nao:isTagFor">nao:isTagFor</a>.<br /> - - - - - - -</p> - - - - - - -<div style="text-align: center;"><img style="width: 533px; height: 174px;" alt="tag class" src="tagClass.png" /><br /> - - - - - - -<a name="Fig_3"></a> -Figure 3. Modelling conventional tagging<span style="font-weight: bold;"></span></div> - - - - - - -<br /> - - - - - - -<h3><a class="mozTocH3" name="mozTocId873837"></a><a name="2.4._Generic_Annotation_Example"></a>2.4. -Generic Annotation Example</h3> - - - - - - -<div style="text-align: justify;"> -<p>A person wants to annotate a file of type -image/photo on their personal desktop. The photo depicts a friend, -Claudia, drinking coffee in the -SAP offices. The user states that the photo 'is related' (via -nao:isRelated - a symmetric property) to the following resources:</p> - - - - - - -<ul> - - - - - - - <li>[1] a resource representing Claudia on the user's desktop -(ex:Claudia) </li> - - - - - - - <li>[2] a resource representing the organisation SAP on the -user's desktop (ex:SAP)</li> - - - - - - -</ul> - - - - - - -Furthermore, the user states that the photo 'is about' (via -nao:hasTopic) the following resources: -<ul> - - - - - - - <li>[3] a concept from a Work ontology defining a colleague at -work (work:Colleague)</li> - - - - - - - <li>[4] a concept from a Work ontology defining a -working office (work:Office)</li> - - - - - - -</ul> - - - - - - -[5] The user defines a custom personal identifier for the photo, -'ClaudiaOffice20070815'.<br /> - - - - - - -[6] Finally, the user also tags the photo with an instance of nao:Tag -they create:<br /> - - - - - - -<ul> - - - - - - - <li>[7],[8] The user labels the new tag 'Work', with the -alternative labels 'SAP' and 'WorkPlace'.</li> - - - - - - - <li>[9],[10] The user also selects an icon for the new tag that -they -find on their desktop, and creates a custom description for the new tag.</li> - - - - - - -</ul> - - - - - - -<p>The resulting statements are generated and stored -within a -named graph 'ex:i1'. Apart from the obvious statements, -note the -following automatically generated statements </p> - - - - - - -<ul> - - - - - - - <li>[11] Since nao:hasTag has the inverse property -nao:isTagFor, the -newly generated tag is also related to the tagged resource via this -inverse property.<br /> - - - - - - - </li> - - - - - - - <li>[12] The icon used as a symbol for the tag (ex:WorkIcon) is -now also an instance of nao:Symbol.</li> - - - - - - - <li>Since nao:isRelated is symmetric the resources related to -the -photo via this property (ex:SAP and ex:Claudia) are themselves defined -as related to the photo.</li> - - - - - - -</ul> - - - - - - -<p> </p> - - - - - - -</div> - - - - - - -<br /> - - - - - - -<table style="text-align: left; font-family: monospace; width: 100%;" border="1" cellpadding="2" cellspacing="2"> - - - - - - - <tbody> - - - - - - - <tr> - - - - - - - <td><span style="font-family: monospace;"> - ex:i1 {</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[1] ex:DSCF001 </span><span style="font-family: monospace;">nao:isRelated ex:Claudia ,</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[2] - - - - - ex:SAP ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[3] - - nao:hasTopic work:Colleague ,</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[4] - - - - work:Office ;<br /> - - - - - - - </span><span style="font-family: monospace;">[5] - - nao:personalIdentifier "ClaudiaOffice20070815" ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[6] - nao:hasTag -ex:Work .</span><br style="font-family: monospace;" /> - - - - - - - <br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"> - -ex:Work a nao:Tag ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[7] - - nao:prefLabel "Work" ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[8] - nao:altLabel -"WorkPlace" ,</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"> - - - "SAP" ;</span><span style="font-family: monospace;"><br /> - - - - - - -[9] - </span><span style="font-family: monospace;">nao:hasSymbol ex:WorkIcon ;</span><span style="font-family: monospace;"> </span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[10] - </span><span style="font-family: monospace;"></span><span style="font-family: monospace;">nao:description "Represents -all about my work, workplace, workmates -etc" ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[11] - nao:isTagFor ex:DSCF001 .</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"> - </span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[12] -ex:WorkIcon a nao:Symbol . </span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"> - </span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[13] ex:SAP -nao:isRelated ex:DSCF001 .</span><br style="font-family: monospace;" /> - - - - - - - <br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[14] -ex:Claudia nao:isRelated ex:DSCF001 . }</span> </td> - - - - - - - </tr> - - - - - - - - - - - - </tbody> -</table> - - - - - - -<br /> - - - - - - -<h2><a class="mozTocH2" name="mozTocId836701"></a><a name="3._Graph_Metadata_Vocabulary"></a>3. Graph -Metadata Vocabulary</h2> - - - - - - -<div style="text-align: center;"> -<div style="text-align: justify;"> -<p>In this section we -provide the -description and specifications for the subpart of the annotation -ontology dealing with Graph Metadata. Graph metadata -is a form of annotation where the subject of the annotations -are -named graphs, as specified in [<a href="#References">NRL -SPECIFICATION</a>]. -Given the important and central role that named graphs have in the NRL -concept, this graph metadata, or graph annotation, vocabulary is -considered to be part of the -annotation ontology, and the properties are subproperties -of nao:annotation. </p> - - - - - - -<p>NRL already provides vocabulary -that is -used to define essential graph metadata [See <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2._Graph_Roles_Vocabulary">Graph -Roles Vocabulary</a>], -including graph role speficiation and whether the graph is a document -graph (see <a href="#Fig_4">Fig.4.</a>), whether -a graph is updatable or otherwise (via <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl/#mozTocId379929">nrl:updatable</a>) -and specification of the declarative -semantics for a graph (via <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl/#mozTocId737534">nrl:hasSemantics</a>).</p> - - - - - - -<p>Generic annotation vocabulary given in this ontology is also -applicable to named graphs (which are in fact special cases of a -resource). In particular, <a href="#2.2.14._nao:creator">nao:creator</a>, -<a href="#2.2.15._nao:contributor">nao:contributor</a>, -<a href="#2.2.17._nao:created">nao:created </a>and <a href="#2.2.18._nao:lastModified">nao:lastModified</a> -are of special relevance when it comes to providing metadata for a -named graph. The vocabulary provided in this section enables additional -graph annotations to those provided by NRL and by the NAO generic -annotation vocabulary. An example that makes full use of all the -relevant vocabulary is given in <a href="#3.3._Graph_Metadata_Example">Section 3.3</a>.<br /> - - - - - - -</p> - - - - - - -<p> -In -contrast to vocabularies like the Ontology Metadata Vocabulary [<a href="#References">OMV REPORT</a>], -which was a major source of inspiration for this vocabulary, our -vocabulary -is applicable to all Graph Roles as defined in NRL (<a href="#Fig_4">Fig.4.</a>), -and not -just ontologies. The majority of graph metadata properties thus have -nrl:Data as their domain. Other properties apply specifically -to nrl:DocumentGraph (documents that encode -named graphs). <span style="background-color: rgb(255, 255, 255);"></span></p> - - - - - - -<span style="background-color: rgb(255, 255, 255);"></span></div> - - - - - - -<div style="text-align: center;"><img style="width: 602px; height: 349px;" alt="roles" src="NamedGraphs.png" /><br /> - - - - - - -</div> - - - - - - -<div style="text-align: center;"><a name="Fig_4"></a> -Figure 4. Graph Roles Hierarchy</div> - - - - - - -<br /> - - - - - - -<div style="text-align: justify;"> -<p>While generic annotation -for a resource is usually stored within the graph where the resource is -defined, -metadata about a graph is stored outside that graph, in a -separate but associated metadata graph. <span style="background-color: rgb(255, 255, 255);">These special -graphs -are marked using the [<a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.7._nrl:GraphMetadata">nrl:GraphMetadata</a>] -role, also shown in <a href="#Fig_4">Fig.4.</a> and -linked to their respective graphs via [<a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.8._nrl:graphMetadataFor">nrl:graphMetadataFor</a>]. -The unique metadata graph that defines the non-subjective attributes -(graph role, semantics, -namespace, etc) for a graph is instead linked to that graph -via [<a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.9._nrl:coreGraphMetadataFor">nrl:coreGraphMetadataFor</a>].</span></p> - - - - - - -</div> - - - - - - -<h3><a class="mozTocH3" name="mozTocId215877"></a><a name="3.1_General_Graph_Metadata_Vocabulary"></a>3.1 -General Graph Metadata</h3> - - - - - - -<div style="text-align: justify;"> -<p>The following vocabulary -applies to -all NRL Graph Roles. Although some of them appear to be -ontology-specific, -properties which apply to e.g. both -nrl:InstanceBase and nrl:Ontology are listed here, since their common -superclass is nrl:Data. Given that graph metadata is considered to be a -special case of annotation, most of the vocabulary consists of -subproperties of nao:annotation. These properties are depicted -in -<a href="#Fig_5">Fig.5.</a> and described -individually in the following subsections. -Although the use of none of these properties is compulsory, their use -is recommended as a best practice.</p> - - - - - - -</div> - - - - - - -<br /> - - - - - - -<div style="text-align: center;"><img style="width: 706px; height: 264px;" alt="Data Properties" src="DataProperties.png" /><br /> - - - - - - -<br /> - - - - - - -<a name="Fig_5"></a> -Figure 5. General Graph Metadata properties<br /> - - - - - - -</div> - - - - - - -<br /> - - - - - - -<h4><a class="mozTocH4" name="mozTocId925972"></a><a name="3.1.4._nao:hasDefaultNamespace"></a>3.1.4. -nao:hasDefaultNamespace</h4> - - - - - - -<div style="text-align: justify;">This property -explicitally defines the default namespace for a -named graph. The value for this property should therefore be a valid -URI ending with the '#' sign.<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId505129"></a><a name="3.1.5._nao:hasDefaultNamespaceAbbreviation"></a>3.1.5. -nao:hasDefaultNamespaceAbbreviation</h4> - - - - - - -<div style="text-align: justify;">A default namespace -abbreviation for a named graph can be defined via the use of this -property. This prevents a scenario where different random -abbreviations are generated from different applications for the same -graph.<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId297228"></a><a name="3.1.6._nao:engineeringTool"></a>3.1.6. -nao:engineeringTool<br /> - - - - - - -</h4> - - - - - - -<div style="text-align: justify;">Graphs that are -generated via a specific graph engineering tool can make use of this -property. -The value is a string stating the name of the editing tool.<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId652689"></a><a name="3.1.7._nao:version"></a>3.1.7. nao:version</h4> - - - - - - -<div style="text-align: justify;">This property specifies -version -information for the graph role and is particularly useful -for tracking, -comparing and -merging data. Legal values for this property are of the [<a href="http://www.w3.org/TR/xmlschema-2/#float">xsd:float</a>] -datatype. A graph can have at most one version, hence the -maximum cardinality is 1. -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId642918"></a><a name="3.1.8._nao:status"></a>3.1.8. nao:status</h4> - - - - - - -<div style="text-align: justify;">Tracking -information for the contents of a graph can be specified via this -property. Typical values, of type string, -include "Stable", "Unstable" and "Testing". -</div> - - - - - - -<br /> - - - - - - -<h3><a class="mozTocH3" name="mozTocId370287"></a><a name="3.2._Document_Graph_Metadata"></a>3.2. Document -Graph Metadata</h3> - - - - - - -<div style="text-align: justify;"> -A special class in the NRL specifications, [<a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.1.2._nrl:DocumentGraph">nrl:DocumentGraph</a>], -is defined to mark graphs that are completely represented within a -document which can be accessed via a URL, which effectively also -becomes the name of the graph. The following property, also shown in -<a href="Fig_6">Fig.6.</a>, applies only to -instances of such graphs.<br /> - - - - - - -</div> - - - - - - -<br /> - - - - - - -<div style="text-align: center;"><img style="width: 476px; height: 84px;" alt="Document Graph" src="DocumentGraph.png" /><br /> - - - - - - -<a name="Fig_6"></a> -Figure 6. Graph Metadata for Graphs encoded in documents<br /> - - - - - - -</div> - - - - - - -<h4><a class="mozTocH4" name="mozTocId89753"></a><a name="3.3.1._nao:serializationLanguage"></a>3.3.1. -nao:serializationLanguage</h4> - - - - - - -<div style="text-align: justify;"> -This property states the graph serialization -language for the document, e.g. XML/RDFS, RDFS/N3, TriG etc.<br /> - - - - - - -</div> - - - - - - -<br /> - - - - - - -<h3><a class="mozTocH2" name="mozTocId785190"></a><a name="3.3._Graph_Metadata_Example"></a>3.3. Graph -Metadata Example</h3> - - - - - - -<div style="text-align: justify;"> -<p>The following example demonstrates the use and best practice -for the Graph Metadata Vocabulary given in this section.</p> - - - - - - -</div> - - - - - - -<div style="text-align: justify;">[1] In this example we -assume that a named graph with the role of an ontology exists and is -given by ex:o1.<br /> - - - - - - -[2] Graph metadata for this ontology is provided by the metadata graph -ex:o1_metadata. This graph consists of annotations for the -ontology stored in graph ex:o1. These annotations are defined using the -graph metadata vocabulary specified in this document. <br /> - - - - - - -[3],[4] The metadata graph includes first and foremost a description -about itself, stating that it is indeed a named graph with a -nrl:GraphMetadata role. It is further stated that this is the core -graph -metadata that defines the core properties for the graph -ex:o1, via <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.9._nrl:coreGraphMetadataFor">nrl:coreGraphMetadataFor</a>.<br /> - - - - - - -[5] Metadata for the actual graph being described is then provided. -This metadata includes the following:<br /> - - - - - - -<ul> - - - - - - - <li>[6] The creator of the ontology is defined to be ex:SAP, -with two -separate contributors being ex:Dirk and ex:Claudia. This automatically -generates the statement <span style="background-color: rgb(255, 255, 255);">(usually not -within this -graph)</span> that ex:SAP, ex:Dirk -and ex:Claudia are annotators and therefore instances of nao:Party.</li> - - - - - - - <li>[7] The ontology is defined to be 'Stable' at version 1.2. -The last modified time is also represented.</li> - - - - - - - <li>[8] A static, standard namespace and namespace -abbreviation are defined.</li> - - - - - - - <li>[9] The graph is said to be non-updatable, meaning that if -the -ontology needs to be changed, a new version needs to be generated while -leaving the original unchanged. See <a href="http://www.semanticdesktop.org/ontologies/2007/08/15/nrl.html#3.2.14._nrl:updatable">nrl:updatable</a>.</li> - - - - - - -</ul> - - - - - - -</div> - - - - - - -<table style="text-align: left; width: 100%;" border="1" cellpadding="2" cellspacing="2"> - - - - - - - <tbody> - - - - - - - <tr> - - - - - - - <td><span style="font-family: monospace;">[1] </span><span style="font-family: monospace;">ex:o1 {<br /> - - - - - - - # Work Ontology -provided in this named graph<br /> - - - - - - - </span><span style="font-family: monospace;"> - </span><span style="font-family: monospace;"> }<br /> - - - - - - - <br /> - - - - - - - </span><span style="font-family: monospace;">[2] -ex:o1/metadata { </span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[3] - </span><span style="font-family: monospace;">ex:o1/metadata -a nrl:GraphMetadata ;<br /> - - - - - - -[4] - nrl:coreGraphMetadataFor -ex:o1 .</span><span style="font-family: monospace;"> } </span><span style="font-family: monospace;"> <br /> - - - - - - - <br /> - - - - - - -[5] </span><span style="font-family: monospace;">ex:o1 a -nrl:Ontology ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;">[6] - - nao:creator -ex:SAP ;<br /> - - - - - - - - nao:contributor ex:Dirk ,<br /> - - - - - - - - - ex:Claudia ;<br /> - - - - - - - </span><span style="font-family: monospace;">[7] - nao:version "1.2" ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"></span><span style="font-family: monospace;"> - - nao:lastModified "2007-08-15T23:59:55.329Z" .<br /> - - - - - - - </span><span style="font-family: monospace;"> - nao:status "Stable" ;<br /> - - - - - - - </span><span style="font-family: monospace;">[8] - -nao:hasNamespace "http://www.example.org/ontologies/work#" ;</span><br style="font-family: monospace;" /> - - - - - - - <span style="font-family: monospace;"> - nao:hasNamespaceAbbreviation "work" ;<br /> - - - - - - - </span><span style="font-family: monospace;">[9] - nrl:updatable "0" . }<br /> - - - - - - - </span><span style="font-family: monospace;"></span><span style="font-family: monospace;"><br /> - - - - - - - </span></td> - - - - - - - </tr> - - - - - - - - - - - - </tbody> -</table> - - - - - - -</div> - - - - - - -<h2><a class="mozTocH2" name="mozTocId760420"></a><a name="References"></a>References</h2> - - - - - - -<dl> - - - - - - - <dt>[NRL SPECIFICATIONS]</dt> - - - - - - - <dd><a href="http://www.semanticdesktop.org/ontologies/nrl">NEPOMUK Representation -Language (NRL) Vocabulary Specification</a><cite></cite>.</dd> - - - - - - - <dd>NEPOMUK., Task-Force Ontologies.</dd> - - - - - - - <dd><small style="font-family: monospace;"><a href="http://www.semanticdesktop.org/ontologies/nrl">http://www.semanticdesktop.org/ontologies/nrl</a>.</small></dd> - - - - - - -</dl> - - - - - - -<span style="font-weight: bold;">[OMV Report] -<br /> - - - - - - -</span> -<div style="margin-left: 40px;"><a href="http://ontoware.org/projects/omv/">Ontology Metadata -Vocabulary for the Semantic. Web</a>. Jens Hartmann (University -of Karlsruhe), Raul Palma (Universidad Politecnica de Madrid) and Elena -Paslaru Bontas (Free University of Berlin).<small style="font-family: monospace;"><br /> - - - - - - -<a href="http://ontoware.org/projects/omv/">http://ontoware.org/projects/omv/</a>.</small><br /> - - - - - - -<small style="font-family: monospace;"> -</small></div> - - - - - - -<dl> - - - - - - -</dl> - - - - - - -</div> |