SIG-SWO 鯖江 2012年10月5日
LinkedDataにおける識別子とスキー
マ
武田英明
国立情報学研究所
takeda@nii.ac.jp
Hideaki Takeda / National Institute of Informatics
2.
どのようにして
コンピュータにデータを入れる?
• データをどのように記述するか?
–個別のデータの記述の仕方
• スキーマ/クラス/概念 (Schema/Class/Concept)
– データ記述間の関係
• オントロジー/タキソノミー/シソーラス
(Ontology/Taxonomy/Thesaurus)
• 個々のデータをどう参照するか?
– 個別データの識別の仕方
• 識別子(Identifier)
– 識別子同士の関係
Hideaki Takeda / National Institute of Informatics
3.
Architecture for theSemantic Web
クラスの世界(Ontologies)
インスタンスの世界
(Linked Data)
Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/
Hideaki Takeda / National Institute of Informatics
4.
Layers of SemanticWeb
• Ontology
– クラスの記述
– RDFS, OWL
– ontology buildingの課題
• Ontology buildingはそもそも難しい
– 整合性、一貫性、論理性
• オントロジー間の関係はもっと難しい
Descriptions on classes
Ontology
インスタンスに関する記述
Linked Data
Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/
Hideaki Takeda / National Institute of Informatics
5.
Layers of SemanticWeb
• Linked Data
– 個物の記述
– RDF + (RDFS, OWL)
– いい点
• 書きやすい(事実の記述)
• リンクしやすい (事実間の関係)
– よくない点
• 複雑な構造は書きづらい
• それでもクラス記述は必要 (-> ontology)
Descriptions on classes
Ontology
Description on instances
Linked Data
Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/
Hideaki Takeda / National Institute of Informatics
識別子のまとめ
• 識別子はLODのコア
–データの手に入りやすさ Data availability
– データの一貫性 Data inconsistency
– データの相互運用性 Data interoperability
• よい識別子システムを構築することは信
頼でき持続可能なLODをつくることにつな
がる
Hideaki Takeda / National Institute of Informatics
UDC ELEMENT DEFINITION
UDC as Linked Data SKOS TERM UDC
SUBPROPERTY
UDC number (notation) UDC notation is combination of symbols (numerals, signs and letters) that represent a class, its skos:notation ---
position in the hierarchy and its relation to other classes. Notation is a language-independent
indexing term that enables mechanical sorting and filing of subjects. Also called 'UDC number'
and 'UDC classmark'
class identifier (URI) A unique identifier assigned to each UDC class. It identifies the relationship between a class' skos:Concept ---
meaning and its notational representation
broader class (URI) Superordinate class: the class hierarchically above the class in question skos:broader ---
caption Verbal description of the class content skos:prefLabel ---
including note Extension of the caption containing verbal examples of the class content (usually a selection of skos:note udc:includingN
important terms that do not appear in the subdivision) ote
application note Instructions for number building, further extension and specification of the class skos:note udc:application
Note
scope note Note explaining the extent and the meaning of a UDC class. Used to resolve disambiguation or skos:scopeNot ---
to distinguish this class from other similar classes e
examples Examples of combination are used to illustrate UDC class building i.e. complex subject skos:example ---
statements
see also reference Indication of conceptual relationship between UDC classes from different hierarchies skos:related ---
<skos:Concept rdf:about="http://udcdata.info/025553">
69,000 records <skos:inScheme rdf:resource="http://udcdata.info/udc-schema"/>
40 Languages <skos:broader rdf:resource="http://udcdata.info/025461"/>
<skos:notation rdf:datatype="http://udcdata.info/UDCnotation">510.6</skos:notation>
<skos:prefLabel xml:lang="en">Mathematical logic</skos:prefLabel>
<skos:prefLabel xml:lang="ja">記号論理学</skos:prefLabel>
<skos:related rdf:resource="http://udcdata.info/000016"/>
http://udcdata.info/ </skos:Concept>
Hideaki Takeda / National Institute of Informatics