1. SIG-SWO 鯖江 2012年10月5日
Linked Data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 the Semantic 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 Semantic Web
• 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 Semantic Web
• 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
15. 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
20. 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