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2012 INTERNATIONAL ASIAN SUMMER SCHOOL IN LINKED DATA             IASLOD 2012, August 13-17, 2012, KAIST, Daejeon, Korea  ...
Semantic Web and Linked Data• Semantic Web   – What is Semantic Web   – How to realize Semantic Web       •   Metadata    ...
Semantic Web      Hideaki Takeda / National Institute of Informatics
The Aim of The Semantic Web• "The Semantic Web is an extension of the current web in  which information is given well-defi...
Semantic Web• Realization of various information exchanging via Web                                  Automation           ...
Next Generation Web?• Evolution of Web   – HTML: Web for Display   – XML: Web with Syntax   – ?? : Web with Semantics• Why...
A brief introduction of XML• Limitation of HTML   – Chaos by mixture of displaying and text structures        • e.g.,     ...
XML• XML(eXtensible Markup Language)  – Can define original tags  – Represent logical structures of data     • DTD  – Do n...
Whey is XML not sufficient?<person>                                 <個人>  <name> Hideaki Takeda</name>             <名前>Hid...
Architecture for the Semantic Web   Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/                         ...
How to describe “meaning”?• Need to describe “information on information”  – “Meaning of something” is a description (“mea...
Metadata• What is metadata?  – Data about data  – What one can say about any information object• What is described as meta...
Metadata• Metadata to individual information objects  – Bibliography,Dublin Core• Metadata to part or structure of informa...
A Layer model for Semantic Web•   RDF (Resource Description Framework)     – The most primitive model for metadata descrip...
RDF (Resource Description             Framework)• A framework to describe metadata• Separation of model and syntax• W3C Re...
RDF Model• Element  – Resource:     • URI(Universal Resource Identifier)     • Literal(string)        – No need to be spec...
RDF model•   Statement     – Creator of http://www-kasm.nii.ac.jp/~takeda is “Hideaki Takeda”•   Structure     – Resource ...
RDF model•   Creator of http://www-kasm.nii.ac.jp/~takeda is http://www.nii.ac.jp/staffid/123456 which    has name “Hideak...
RDF model• Creator of http://www-kasm.nii.ac.jp/~takeda has name  “Hideaki Takeda” email “takeda@nii.ac.jp” .             ...
RDF syntax• Creator of http://www-kasm.nii.ac.jp/~takeda is “Hideaki Takeda”                                            Cr...
RDFS (RDF Schema)• Stronger knowledge representation model   – RDF: ER model,semantic net   – RDF Schema: Frame model,obje...
RDFS•   Class Definition     – rdfs:Resource     – rdfs:Class     – rdf:Property     – rdfs:ConstraintProperty     – rdfs:...
RDF Schema• rdfs:Class                       Range• rdfs:SubclassOf                     Only one  – Detailed class      ...
<rdf:RDF xml:lang="en"               RDF Schema  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" “The class of per...
OWL(Web Ontology Language)•   More general knowledge representation•   Based on Description Logics•   Features     – Class...
Linked Data     Hideaki Takeda / National Institute of Informatics
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
Architecture for the Semantic Web   The world of classes (Ontologies)   The world of instances    (Linked Data)         ...
Layers of Semantic Web• Ontology   – Descriptions on classes   – RDFS, OWL   – Challenges for ontology building       • On...
Layers of Semantic Web• Linked Data   – Descriptions on instances (individuals)   – RDF + (RDFS, OWL)   – Pros for Linked ...
Linked Data   Linked Data is “Web of Data”     – Data published as RDF     – Can refer from outside• The four rules for L...
Linked Data• The four rules for Linked Data   – Use URIs as names for things       • Give a URI to every object in the wor...
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
Linking Open Data (LOD)•   The project to collect published Linked Data•   Major Linked Data•   (Translated from the origi...
Hideaki Takeda / National Institute of Informatics
Hideaki Takeda / National Institute of Informatics
LOD Cloud(Linking Open Data)         Hideaki Takeda / National Institute of Informatics
http://dbpedia.org/page/TokyoHideaki Takeda / National Institute of Informatics
http://en.wikipedia.org/wiki/TokyoHideaki Takeda / National Institute of Informatics
Hideaki Takeda / National Institute of Informatics
Hideaki Takeda / National Institute of Informatics
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
How to use Linked DataLinked Data            Linked Data                Linked Data  Browser                Mashup        ...
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
Linked Data Browser• Browse linked data just as browsing web pages  – Show RDF data  – Prompt links to follow• System/Serv...
Hideaki Takeda / National Institute of Informatics
Tabulator    Hideaki Takeda / National Institute of Informatics
Hideaki Takeda / National Institute of Informatics
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
Linked Data Search Engine• Search RDF data with crawled data set  – Swoogle  – Sindice  – watson                        Hi...
http://sindice.com/Hideaki Takeda / National Institute of Informatics
Hideaki Takeda / National Institute of Informatics
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
How to use Linked Data• Semantic Data Mash-up Applications  – SemaPlorer     • http://btc.isweb.uni-koblenz.de/  – Dbpedia...
DBpedia Mobile                 Hideaki Takeda / National Institute of Informatics
Bio2RDF• Search LOD in  bioscience• Translate data into RDF  if not                            Hideaki Takeda / National I...
Bio2RDF   Hideaki Takeda / National Institute of Informatics
Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data  – Linking Open Data (LOD)• How to use Linked Data ...
RDFa• Add extra structured content to the (X)HTML  pages  – adds new (X)HTML/XML attributes     • “RDF in attributes”  – P...
Principles of RDFa• RDF contents are defined through XML  attributes (no elements)• XML/HTML tree structure is used• Vario...
Examples http://example.com/alice/posts/trouble_with_bob <div xmlns:dc="http://purl.org/dc/elements/1.1/">  <h2 property="...
<div xmlns:dc="http://purl.org/dc/elements/1.1/"> <div about="/alice/posts/trouble_with_bob">   <h2 property="dc:title">Th...
<div about="/alice/posts/trouble_with_bob"> <h2 property="dc:title">The trouble with Bob</h2>   The trouble with Bob is th...
<div typeof="foaf:Person" xmlns:foaf="http://xmlns.com/foaf/0.1/"> <p property="foaf:name"> Alice Birpemswick </p> <p> Ema...
<div xmlns:foaf="http://xmlns.com/foaf/0.1/" about="#me" rel="foaf:knows"> <ul>  <li typeof="foaf:Person">    <a property=...
Using RDFa• RDF Validator  – http://validator.w3.org/• RDF Distiller  – http://www.w3.org/2007/08/pyRdfa/                 ...
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN"  "http://www.w3.org/MarkUp/DT...
Summary• Linked Data is the practical application of  Semantic Web  – The bottom-up approach  – Postpone the ontology issu...
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General Introduction for Semantic Web and Linked Open Data

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2012 INTERNATIONAL ASIAN SUMMER SCHOOL IN LINKED DATA 
IASLOD 2012, August 13-17, 2012, KAIST, Daejeon, Korea

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Transcript of "General Introduction for Semantic Web and Linked Open Data"

  1. 1. 2012 INTERNATIONAL ASIAN SUMMER SCHOOL IN LINKED DATA IASLOD 2012, August 13-17, 2012, KAIST, Daejeon, Korea General Introductionfor Semantic Web and Linked Open Data Hideaki Takeda National Institute of Informatics takeda@nii.ac.jp Hideaki Takeda / National Institute of Informatics
  2. 2. Semantic Web and Linked Data• Semantic Web – What is Semantic Web – How to realize Semantic Web • Metadata • RDF • RDFS • OWL• Linked Data – What is Linked Data? – The State-of-the-Art of Linked Data • Linking Open Data (LOD) – How to use Linked Data • Linked Data Browser • Linked Data Search Engine • Linked Data Applications – How to use RDF • RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  3. 3. Semantic Web Hideaki Takeda / National Institute of Informatics
  4. 4. The Aim of The Semantic Web• "The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." The Semantic Web, Scientific American, May 2001, Tim Berners-Lee, James Hendler and Ora Lassila• The Semantic Web is a vision: the idea of having data on the web defined and linked in a way that it can be used by machines not just for display purposes, but for automation, integration and reuse of data across various applications. http://www.w3.org/2001/sw/ Hideaki Takeda / National Institute of Informatics
  5. 5. Semantic Web• Realization of various information exchanging via Web Automation 自動化 Integration 統合 Re-use of data データの再利用 Hideaki Takeda / National Institute of Informatics
  6. 6. Next Generation Web?• Evolution of Web – HTML: Web for Display – XML: Web with Syntax – ?? : Web with Semantics• Why should we embed semantics into Web? From – Web for Human To – Web for human and machines cf. Web for machines Hideaki Takeda / National Institute of Informatics
  7. 7. A brief introduction of XML• Limitation of HTML – Chaos by mixture of displaying and text structures • e.g., – <h3></h3> should be used for “the third-level heading”, but are often used just for bigger fonts – <b></b> is specifying “bold” , not “emphasis”. – Fixed Structure • e.g., – If you need <h7></h7>…. – I need a structure just for my data <h1> A list of lectures</h1> <h2> Knowledge Sharing Systems</h2> <h3> Lecturer: Hideaki Takeda</h3> <h3>Wednesday 3rd</h3> Hideaki Takeda / National Institute of Informatics
  8. 8. XML• XML(eXtensible Markup Language) – Can define original tags – Represent logical structures of data • DTD – Do not include style information <lecturelist> • XST <lecture> <title id=1234> Knowledge Sharing Systems</title> <lecturer> Hideaki Takeda</lecturer> <schedule> <week>Wednesday</week> <time>3rd</time> </lecture> ... </lecturelist> Hideaki Takeda / National Institute of Informatics
  9. 9. Whey is XML not sufficient?<person> <個人> <name> Hideaki Takeda</name> <名前>Hideaki Takeda</名前> <age> 20</age> <年齢> 20</年齢></person> </個人>• What are specified by “person” and “name” ?• Is “name” and “名前” the same?• Is this description sufficient as a description for “person”?• …• In short, syntax alone cannot solve these problems Hideaki Takeda / National Institute of Informatics
  10. 10. Architecture for the Semantic Web Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/ Hideaki Takeda / National Institute of Informatics
  11. 11. How to describe “meaning”?• Need to describe “information on information” – “Meaning of something” is a description (“meaning”) to a description (“something”) in computers – Metadata • Data about data• Need to architecture for common understanding – Syntax (language or scheme) – Vocabulary (ontology) Hideaki Takeda / National Institute of Informatics
  12. 12. Metadata• What is metadata? – Data about data – What one can say about any information object• What is described as metadata? – Content relates to what the object contains or is about, and is intrinsic to an information object. – Context indicates the who, what, why, where, how aspects associated with the objects creation and is extrinsic to an information object. – Structure relates to the formal set of associations within or among individual information objects and can be intrinsic or extrinsic Setting the State, Anne J.Gilliand-Swetland, Introduction to Metadata – Pathways to Digital Information, Murthsa Baca (ed.), Getty Information Institute. Hideaki Takeda / National Institute of Informatics
  13. 13. Metadata• Metadata to individual information objects – Bibliography,Dublin Core• Metadata to part or structure of information objects – Drawings,RDF,RDFS, OWL Type:tractor Owner:Taro Product year:2002 Body Axis: Connect body to wheel Wheel Hideaki Takeda / National Institute of Informatics
  14. 14. A Layer model for Semantic Web• RDF (Resource Description Framework) – The most primitive model for metadata description • SVO model • Entity-Relation Model • Semantic net• RDF Schema – Addition of “concept” to RDF • class-subclass,constraints• OWL – More general concept description language • Logical consistency • Various class expressions • Various constraints• DAML-S – Descriptions on processes Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/ Hideaki Takeda / National Institute of Informatics
  15. 15. RDF (Resource Description Framework)• A framework to describe metadata• Separation of model and syntax• W3C Recommendation (2004) Hideaki Takeda / National Institute of Informatics
  16. 16. RDF Model• Element – Resource: • URI(Universal Resource Identifier) • Literal(string) – No need to be specified by Web – Property: • Attribute when describing resources • URI or Literal just as Resource – Statement: triad of resource, property, and resource Hideaki Takeda / National Institute of Informatics
  17. 17. RDF model• Statement – Creator of http://www-kasm.nii.ac.jp/~takeda is “Hideaki Takeda”• Structure – Resource (subject): http://www-kasm.nii.ac.jp/~takeda – Property (predicate): Creator – Value (object): “Hideaki Takeda” Creator http://www-kasm.nii.ac.jp/~takeda “Hideaki Takeda” Resource Property Value Hideaki Takeda / National Institute of Informatics
  18. 18. RDF model• Creator of http://www-kasm.nii.ac.jp/~takeda is http://www.nii.ac.jp/staffid/123456 which has name “Hideaki Takeda” and email “takeda@nii.ac.jp” . Creator http://www-kasm.nii.ac.jp/~takeda http://www.nii.ac.jp/staffid/123456 name email “Hideaki Takeda” “takeda@nii.ac.jp” Hideaki Takeda / National Institute of Informatics
  19. 19. RDF model• Creator of http://www-kasm.nii.ac.jp/~takeda has name “Hideaki Takeda” email “takeda@nii.ac.jp” . Creator http://www-kasm.nii.ac.jp/~takeda name email “Hideaki Takeda” “takeda@nii.ac.jp” Hideaki Takeda / National Institute of Informatics
  20. 20. RDF syntax• Creator of http://www-kasm.nii.ac.jp/~takeda is “Hideaki Takeda” Creator http://www-kasm.nii.ac.jp/~takeda “Hideaki Takeda” Resource Property Value <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://dublincore.org/2001/08/14/dces#"> <rdf:Description about="http://www-kasm.nii.ac.jp/~takeda"> <dc:Creator>Hideaki Takeda</dc:Creator> </rdf:Description> </rdf:RDF> <rdf:RDF> <rdf:Description about="http://www-kasm.nii.ac.jp/~takeda"> <dc:Creator rdf:resource=“Hideaki Takeda” /> </rdf:Description> </rdf:RDF> Hideaki Takeda / National Institute of Informatics
  21. 21. RDFS (RDF Schema)• Stronger knowledge representation model – RDF: ER model,semantic net – RDF Schema: Frame model,object-oriented paradigm • Minimal definition • Property-centered approach• RDFS is defined as extension of RDF• RDFS gives definitions of RDF descriptions Hideaki Takeda / National Institute of Informatics
  22. 22. RDFS• Class Definition – rdfs:Resource – rdfs:Class – rdf:Property – rdfs:ConstraintProperty – rdfs:Literal• Property Definition – rdf:type – rdfs:subClassOf – rdfs:subPropertyOf – rdfs:comment – rdfs:label – rdfs:seeAlso – rdfs:isDefinedBy• ConstraintProperty Definition – rdfs:range RDFS Structure by RDF – rdfs:domain Resource Description Framework(RDF) Schema Specification 1.0 http://www.w3.org/TR/2000/CR-rdf-schema-20000327/ Hideaki Takeda / National Institute of Informatics
  23. 23. RDF Schema• rdfs:Class  Range• rdfs:SubclassOf  Only one – Detailed class  No cardinality – Multiple  Domain – Transivity  Multiple (or)• rdf:type – Indicate an instance of a class• rdf:property – Attribute• rdfs:subPropertyOf – Detailed property – Transivity Hideaki Takeda / National Institute of Informatics
  24. 24. <rdf:RDF xml:lang="en" RDF Schema xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" “The class of person” Animal s xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> rdfs:comment<rdfs:Class rdf:ID="Person"> Person <rdfs:comment>The class of people.</rdfs:comment> d d <rdfs:subClassOf rdf:resource="http://www.w3.org/ maritalStatus d 2000/03/example/ r ssn classes#Animal"/> age</rdfs:Class> MaritalStatus r<rdf:Property ID="maritalStatus"> rdfs:comment <rdfs:range rdf:resource="#MaritalStatus"/> Integer <rdfs:domain rdf:resource="#Person"/> t t</rdf:Property> Married “Social Security Number”<rdf:Property ID="ssn"> t Single <rdfs:comment>Social Security Number</rdfs:comment> Windowed <rdfs:range t = rdf:type rdf:resource="http://www.w3.org/2000/03/example/classes#Integer"/> t d = rdfs:domain <rdfs:domain rdf:resource="#Person"/> Divorced r = rdfs:range</rdf:Property> = class<rdf:Property ID="age"> = class instance <rdfs:range = property rdf:resource="http://www.w3.org/2000/03/example/classes#Integer"/> <rdfs:domain rdf:resource="#Person"/></rdf:Property><rdfs:Class rdf:ID="MaritalStatus"/><MaritalStatus rdf:ID="Married"/><MaritalStatus rdf:ID="Divorced"/> Resource Description Framework(RDF) Schema Specification 1.0<MaritalStatus rdf:ID="Single"/> http://www.w3.org/TR/2000/CR-rdf-schema-20000327/<MaritalStatus rdf:ID="Widowed"/></rdf:RDF> Hideaki Takeda / National Institute of Informatics
  25. 25. OWL(Web Ontology Language)• More general knowledge representation• Based on Description Logics• Features – Class • Necessary condition / necessary and sufficient condition • Class expression: – Constraint by property » Like slot definition of a class » Type constraint (all/some), cardinality, typed cardinality – Logical operation of classes: union, intersection, negation – Property • Multiple ranges and domains • Specifying meta-property – Import of definitions Hideaki Takeda / National Institute of Informatics
  26. 26. Linked Data Hideaki Takeda / National Institute of Informatics
  27. 27. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  28. 28. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  29. 29. Architecture for the Semantic Web The world of classes (Ontologies) The world of instances (Linked Data) Tim Berners-Lee http://www.w3.org/2002/Talks/09-lcs-sweb-tbl/ Hideaki Takeda / National Institute of Informatics
  30. 30. Layers of Semantic Web• Ontology – Descriptions on classes – RDFS, OWL – Challenges for ontology building • Ontology building is difficult by nature – Consistency, comprehensiveness, logicality • Alignment of ontologies is more difficult 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
  31. 31. Layers of Semantic Web• Linked Data – Descriptions on instances (individuals) – RDF + (RDFS, OWL) – Pros for Linked Data • Easy to write (mainly fact description) • Easy to link (fact to fact link) – Cons for Linked Data • Difficult to describe complex structures • Still need for class description (-> 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
  32. 32. Linked Data Linked Data is “Web of Data” – Data published as RDF – Can refer from outside• The four rules for Linked Data Hideaki Takeda / National Institute of Informatics
  33. 33. Linked Data• The four rules for Linked Data – Use URIs as names for things • Give a URI to every object in the world! – Use HTTP URIs so that people can look up those names. • Don’t use URN – When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL) • Provide machine-readable data for URI – Include links to other URIs. so that they can discover more things. • Make data linked together just like Web Linked Data, TBL, http://www.w3.org/DesignIssues/LinkedData.html Hideaki Takeda / National Institute of Informatics
  34. 34. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  35. 35. Linking Open Data (LOD)• The project to collect published Linked Data• Major Linked Data• (Translated from the original resources) – Dbpedia (Wikipedia) 270 Million Triples – Geonames:Geo names and their latitudes and longitudes, 93 Million Triples – MusicBrainz:Music – WordNet:Dictionary – DBLP bibliography:Bibliography for technical papers. 28 Million Triples – US Census Data: 1 Billion Triples• (Crawling) – FOAF (Friend Of A Friend)• (Wrapper) – Flickr Wrapper Hideaki Takeda / National Institute of Informatics
  36. 36. Hideaki Takeda / National Institute of Informatics
  37. 37. Hideaki Takeda / National Institute of Informatics
  38. 38. LOD Cloud(Linking Open Data) Hideaki Takeda / National Institute of Informatics
  39. 39. http://dbpedia.org/page/TokyoHideaki Takeda / National Institute of Informatics
  40. 40. http://en.wikipedia.org/wiki/TokyoHideaki Takeda / National Institute of Informatics
  41. 41. Hideaki Takeda / National Institute of Informatics
  42. 42. Hideaki Takeda / National Institute of Informatics
  43. 43. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  44. 44. How to use Linked DataLinked Data Linked Data Linked Data Browser Mashup Search EngineThings Things Things Things Things Hideaki Takeda / National Institute of Informatics
  45. 45. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  46. 46. Linked Data Browser• Browse linked data just as browsing web pages – Show RDF data – Prompt links to follow• System/Service – Mables • Display data by following links – Tabulator • Firefox plugin/online • Adding information in a single page – Sig.ma • Showing RDF resources which can be operated Hideaki Takeda / National Institute of Informatics
  47. 47. Hideaki Takeda / National Institute of Informatics
  48. 48. Tabulator Hideaki Takeda / National Institute of Informatics
  49. 49. Hideaki Takeda / National Institute of Informatics
  50. 50. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  51. 51. Linked Data Search Engine• Search RDF data with crawled data set – Swoogle – Sindice – watson Hideaki Takeda / National Institute of Informatics
  52. 52. http://sindice.com/Hideaki Takeda / National Institute of Informatics
  53. 53. Hideaki Takeda / National Institute of Informatics
  54. 54. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  55. 55. How to use Linked Data• Semantic Data Mash-up Applications – SemaPlorer • http://btc.isweb.uni-koblenz.de/ – Dbpedia Mobile • http://wiki.dbpedia.org/DBpediaMobile – Bio2RDF • http://bio2rdf.org/ Hideaki Takeda / National Institute of Informatics
  56. 56. DBpedia Mobile Hideaki Takeda / National Institute of Informatics
  57. 57. Bio2RDF• Search LOD in bioscience• Translate data into RDF if not Hideaki Takeda / National Institute of Informatics
  58. 58. Bio2RDF Hideaki Takeda / National Institute of Informatics
  59. 59. Linked Data• What is Linked Data?• The State-of-the-Art of Linked Data – Linking Open Data (LOD)• How to use Linked Data – Linked Data Browser – Linked Data Search Engine – Linked Data Applications• How to use RDF – RDFa – SPARQL Hideaki Takeda / National Institute of Informatics
  60. 60. RDFa• Add extra structured content to the (X)HTML pages – adds new (X)HTML/XML attributes • “RDF in attributes” – Programs can extract those and turn into RDF – Flexibility for using Literals and URI resources Hideaki Takeda / National Institute of Informatics
  61. 61. Principles of RDFa• RDF contents are defined through XML attributes (no elements)• XML/HTML tree structure is used• Various attributes are defined by RDFa – Some attributes (@href, @rel) are also reused• The text content can be also reused Hideaki Takeda / National Institute of Informatics
  62. 62. Examples http://example.com/alice/posts/trouble_with_bob <div xmlns:dc="http://purl.org/dc/elements/1.1/"> <h2 property="dc:title">The trouble with Bob</h2> <h3 property="dc:creator">Alice</h3> ... </div>In N3<http://www.example.com/alice/posts/trouble_with_bob> <http://purl.org/dc/elements/1.1/title> "The Trouble with Bob"; <http://purl.org/dc/elements/1.1/creator> "Alice" . Hideaki Takeda / National Institute of Informatics
  63. 63. <div xmlns:dc="http://purl.org/dc/elements/1.1/"> <div about="/alice/posts/trouble_with_bob"> <h2 property="dc:title">The trouble with Bob</h2> <h3 property="dc:creator">Alice</h3> ... </div> <div about="/alice/posts/jos_barbecue"> <h2 property="dc:title">Jos Barbecue</h2> <h3 property="dc:creator">Eve</h3> ... </div> ...</div> Hideaki Takeda / National Institute of Informatics
  64. 64. <div about="/alice/posts/trouble_with_bob"> <h2 property="dc:title">The trouble with Bob</h2> The trouble with Bob is that he takes much better photos than I do: <div about="http://example.com/bob/photos/sunset.jpg"> <img src="http://example.com/bob/photos/sunset.jpg" /> <span property="dc:title">Beautiful Sunset</span> by <span property="dc:creator">Bob</span>. </div></div> Hideaki Takeda / National Institute of Informatics
  65. 65. <div typeof="foaf:Person" xmlns:foaf="http://xmlns.com/foaf/0.1/"> <p property="foaf:name"> Alice Birpemswick </p> <p> Email: <a rel="foaf:mbox" href="mailto:alice@example.com">alice@example.com</a></p> <p> Phone: <a rel="foaf:phone" href="tel:+1-617-555-7332">+1 617.555.7332</a> </p></div> Hideaki Takeda / National Institute of Informatics
  66. 66. <div xmlns:foaf="http://xmlns.com/foaf/0.1/" about="#me" rel="foaf:knows"> <ul> <li typeof="foaf:Person"> <a property="foaf:name" rel="foaf:homepage" href="http://example.com/bob">Bob</a> </li> <li typeof="foaf:Person"> <a property="foaf:name" rel="foaf:homepage" href="http://example.com/eve">Eve</a> </li> <li typeof="foaf:Person"> <a property="foaf:name" rel="foaf:homepage" href="http://example.com/manu">Manu</a> </li> </ul></div> Hideaki Takeda / National Institute of Informatics
  67. 67. Using RDFa• RDF Validator – http://validator.w3.org/• RDF Distiller – http://www.w3.org/2007/08/pyRdfa/ Hideaki Takeda / National Institute of Informatics
  68. 68. <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xmlns:foaf="http://xmlns.com/foaf/0.1/" <body about="http://example.org/john-d/#me"> xmlns:dc="http://purl.org/dc/elements/1.1/" <h1>Johns Home Page</h1> version="XHTML+RDFa 1.0" xml:lang="en"> <p>My name is <span property="foaf:nick">John D</span> <head> and I like <title>Johns Home Page</title> <a href="http://www.neubauten.org/" rel="foaf:interest" <base href="http://example.org/john-d/" /> xml:lang="de">Einsturzende Neubauten</a>. <meta property="dc:creator" content="Jonathan Doe" /> </p> <link rel="foaf:primaryTopic" <p> href="http://example.org/john-d/#me" /> My <span rel="foaf:interest" </head> resource="urn:ISBN:0752820907">favorite book is the inspiring <span about="urn:ISBN:0752820907"> <cite property="dc:title">Weaving the Web</cite> by <span property="dc:creator">Tim Berners-Lee</span></span> </span> </p> </body> </html> <http://example.org/john-d/> <http://xmlns.com/foaf/0.1/primaryTopic> <http://example.org/john- d/#me>. <http://example.org/john-d/> <http://purl.org/dc/elements/1.1/creator> "Jonathan Doe"@en. <http://example.org/john-d/#me> <http://xmlns.com/foaf/0.1/nick> "John D"@en. <http://example.org/john-d/#me> <http://xmlns.com/foaf/0.1/interest> <http://www.neubauten.org/>. <http://example.org/john-d/#me> <http://xmlns.com/foaf/0.1/interest> <urn:ISBN:0752820907>. <urn:ISBN:0752820907> <http://purl.org/dc/elements/1.1/title> "Weaving the Web"@en. <urn:ISBN:0752820907> <http://purl.org/dc/elements/1.1/creator> "Tim Berners-Lee"@en. Hideaki Takeda / National Institute of Informatics
  69. 69. Summary• Linked Data is the practical application of Semantic Web – The bottom-up approach – Postpone the ontology issue• A technological solution for data sharing – Data science – Open Government Hideaki Takeda / National Institute of Informatics
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