Semantic web


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Semantic web

  1. Agenda• World Wide Web• Semantic Web• Semantic Web Tools and Applications• Linking Open Data• Social Semantic Web• Open Government
  2. Agenda World Wide Web• Semantic Web• Semantic Web Tools and Applications• Linking Open Data• Social Semantic Web• Open Government
  3. World Wide Weba system of interlinked hypertext documentsaccessed via the Internet
  4. Web Architecture the main markup language for displaying web pages and other information that can be displayed in an web browser HTML Document HTTP URIan application protocol for a string of charactersdistributed, collaborative, Protocol Identifier used to identify a namehypermedia information systems or a resource
  5. HTML is usedto display web pagesfor human.
  6. Hyperlink in HTML isa reference to document. <a href=""> HTML </a> <a href=""> Web </a> hyperlink hyperlink
  7. What is problem? same information, but … How to use it for machine as data?
  8. Agenda• World Wide Web Semantic Web• Semantic Web Tools and Applications• Linking Open Data• Social Semantic Web• Open Government
  9. providing a common framework that allows data to be shared andreused across application, enterprise, and community boundaries
  10. Basic Concept for Data Description on the Semantic Web Gasoline 3.0L V6 AWD 24V GDI fuel engine drivetrain wheelbase 4 A6 115” doors transmission body_style type 8-Speed Sedan Automatic Car
  11. Semantic Web Layer Cake
  12. URI (Uniform Resource Identifier)a string of characters used to identify a name or a resource URI URN (Uniform Resource Name) + URL (Uniform Resource Locator) urn:isbn:0451450523 urn:isan:0000-0000-9E59-0000-O-0000-0000-2 urn:issn:0167-6423
  13. to be used as a general method for conceptual description ormodeling of information that is implemented in web resources, using avariety of syntax formats
  14. RDF Example 115”
  15. XML (Extensible Markup Language)a markup language that defines a set of rules for encodingdocuments in a format that is both human-readable and machine-readable <?xml version="1.0" encoding="utf-8"?> <note> <to>Tove</to> <from>Jani</from> <heading>Reminder</heading> <body>Dont forget me this weekend!</body> </note>
  16. RDF/XMLan XML syntax for writing down and exchanging RDF graphs,called RDF/XML <?xml version="1.0"?> <!DOCTYPE rdf:RDF [<!ENTITY xsd "">]> <rdf:RDF xmlns:rdf="" xmlns:car="" xml:base=""> <rdf:Description rdf:ID="A6"> <rdf:type rdf:resource="Car" /> <car:engine rdf:resource="GDI" /> <car:body_style rdf:resource="Sedan" /> <car:doors rdf:datatype="&xsd;int">4</car:doors> ... </rdf:Description> ... </rdf:RDF>
  17. RDFS (RDF Schema) a set of classes with certain properties using the RDF extensible knowledge representation language, providing basic elements for the description of ontologies, otherwise called RDF vocabularies, intended to structure RDF resourcesTBox - terminological component rdf:type car:Vehicle rdf:Property rdfs:Class rdfs:subClassOf rdf:type rdf:type car:Car car:body_style rdfs:domain rdf:type rdfs:range car:A6 car:Sedan car:Style car:body_style rdf:typeABox - assertion component
  18. Ontologyknowledge representation as a set of concepts within a domain, andthe relationships between those conceptsformal, explicit specification of a shared conceptualisation "Ontologies are often equated with taxonomic hierarchies of classes, class definitions, and the subsumption relation, but ontologies need not be limited to these forms. Ontologies are also not limited to conservative definitions — that is, definitions in the traditional logic sense that only introduce terminology and do not add any knowledge about the world. To specify a conceptualization, one needs to state axioms that do constrain the possible interpretations for the defined terms."
  19. OWL (Web Ontology Language)a family of knowledge representation languages for authoringontologies on the Semantic Web
  20. Semantics of RDF, RDFS, and OWLEach language for the Semantic Web provides a formal meaningbased on a model-theoretic semantics in its abstract syntax. car:Vehicle rdfs:subClassOf <x, y> is in IEXT(I(rdfs:subClassOf)) car:Car rdf:type if and only if x and y are in IC and ICEXT(x) is a subset of ICEXT(y) rdf:type car:A6
  21. Language for the Rule DescriptionSWRL (Semantic Web Rule Language) is a proposal for a SemanticWeb rules-language, combining sublanguages of the OWL Web OntologyLanguage (OWL DL and Lite) with those of the Rule Markup Language(Unary/Binary Datalog). hasParent(?x1,?x2) ∧ hasBrother(?x2,?x3) ⇒ hasUncle(?x1,?x3) <ruleml:imp> <ruleml:_rlab ruleml:href="#example1"/> <ruleml:_body> <swrlx:individualPropertyAtom swrlx:property="hasParent"> <ruleml:var>x1</ruleml:var> <ruleml:var>x2</ruleml:var> </swrlx:individualPropertyAtom> <swrlx:individualPropertyAtom swrlx:property="hasBrother"> <ruleml:var>x2</ruleml:var> <ruleml:var>x3</ruleml:var> </swrlx:individualPropertyAtom> </ruleml:_body> <ruleml:_head> <swrlx:individualPropertyAtom swrlx:property="hasUncle"> <ruleml:var>x1</ruleml:var> <ruleml:var>x3</ruleml:var> </swrlx:individualPropertyAtom> </ruleml:_head> </ruleml:imp>
  22. Inferencebeing able to derive new data from data that you already know hasWife if hasParent(?x, ?y) hasParent(?x, ?z) Man(?y) hasParent hasParent Woman(?z) then hasWife(?y, ?z)
  23. SPARQLan RDF query language, that is able to retrieve and manipulate datastored in Resource Description Framework format PREFIX foaf: <> SELECT ?name ?email WHERE { ?person a foaf:Person. ?person foaf:name ?name. ?person foaf:mbox ?email. }
  24. Agenda• World Wide Web• Semantic Web Semantic Web Tools and Applications• Linking Open Data• Social Semantic Web• Open Government
  25. Ontology Editortools that provide complex development environments for Semantic Web applications, goingbeyond a simple library for a programming languageProtégéa free, open source ontology editor and knowledge-base frameworkTopBraid Composera visual modeling environment from industry experts for creating andmanaging domain models and ontologies in the Semantic Web standardsRDF, RDFS and OWLOntoStudioa professional developing environment of ontologies for ontologies andrules with components for the integration of heterogeneous data sources
  26. TopBraid Composer Class Panel Editing Panel Property Panel
  27. Programming Environment for the Semantic Webtools that provide a working environment to develop Semantic Web applications in the formsof application libraries, modules, etcJenaa Java framework to construct Semantic Web Applications for RDF, RDFSand OWL, SPARQL, GRDDLOWL APIa Java interface and implementation for the W3C Web Ontology LanguageOWLSesamean open source RDF database with support for RDFS inferencing andquerying
  28. Jena
  29. Triple Storetools that can be installed to serve as RDF databasesJenaTDB which provides a lightweight, scalable non-transactional storage andSDB which is a SPARQL database subsystem for JenaOpenLink Virtuosoa SQL-ORDBMS and Web Application Server hybrid (aka Universal Sever)that provides SQL, XML, and RDF data management in a singlemultithreaded server processOracle Spatial 11gan open, scalable, secure and reliable RDF management platform basedon a graph data modelOWLIMthe most scalable semantic repository that includes triple store, inferenceengine and SPARQL query engine
  30. OpenLink Virtuoso
  31. SPARQL Endpointtools that can be serve as SPARQL endpoints to large data setsOpenLink Virtuosothe Virtuoso SPARQL query service that implements the SPARQL Protocolfor RDF providing SPARQL query processingOnline Demo: Linked Data interface to local or remote SPARQL protocol serversMost of triple stores support a interface for SPARQL.
  32. Reasonertools that can perform reasoning tasks, typically based on RDFS, OWL, or some rule engineJena, OWL API, OpenLink Virtuoso, Pellet, …Most of programing environments and triple stores support reasoningbased on RDF, RDFS, and OWL semantics and rule.
  33. RDB2RDFtools can be used to extract RDF data from a Relational Database, using either RDB2RDFDirect Mapping or R2RMLD2RQa system for accessing relational databases as virtual, read-only RDFgraphsSpongerthe Linked Data middleware component of Virtuoso that generates LinkedData from a variety of data sources, supporting a wide variety of datarepresentation and serialization formats
  34. online search engines specialized in OWL and/or RDF content,possibly including ontologies and vocabularies
  35. Swooglea search engine for Semantic Web ontologies, documents, termsand data published on the Web
  36. Watsonweb interface for searching ontologies and semantic documentsusing keywords
  37. Naver Semantic Movie Search
  38. Apple’s Sirian intelligent personal assistant and knowledge navigatorwhich works as an application for Apples iOSa natural language user interface to answer questions, makerecommendations, and perform actions by delegating requests to a set ofWeb services
  39. How Siri Works Siri’s knowledge is represented in a unified modeling system that combines ontologies, inference networks, pattern matching agents, dictionaries, and dialog models. ... Siri isn’t a source of data, so it doesn’t expose data using Semantic Web standards.
  40. Google’s Semantic Search They decided to call it “Knowledge Graph”.
  41. Knowledge Grapha knowledge base used by Google to enhance its search engines searchresults with semantic-search information gathered from a widevariety of sources
  42. Agenda• World Wide Web• Semantic Web• Semantic Web Tools and Applications Linking Open Data• Social Semantic Web• Open Government
  43. Linking Open Dataa method of publishing structured data to share information in away that can be read automatically by computers based on standard Webtechnologies such as HTTP and URIs
  44. Components for LOD• URIs (specifically, of the dereferenceable variety)• HTTP• Resource Description Framework (RDF)• Serialization formats (RDFa, RDF/XML, N3, Turtle, and others)
  45. Four Principles of Linked Data1. Use URIs to identify things.2. Use HTTP URIs so that these things can be referred to and looked up ("dereferenced") by people and user agents.3. Provide useful information about the thing when its URI is dereferenced, using standard formats such as RDF/XML.4. Include links to other, related URIs in the exposed data to improve discovery of other related information on the Web.
  46. Linked Open Data star scheme ★ make your stuff available on the Web (whatever format) under an open license ★★ make it available as structured data (e.g., Excel instead of image scan of a table) ★★★ use non-proprietary formats (e.g., CSV instead of Excel) ★★★★ use URIs to identify things, so that people can point at your stuff★★★★★ link your data to other data to provide context
  47. 2007-11-10 2008-09-18 2009-07-14 2010-09-22 2011-09-19
  48. DBPediaa project aiming to extract structured content from the informationcreated as part of the Wikipedia project using the ResourceDescription Framework (RDF) to represent the extractedinformationmore than 3.64 million things, out of which 1.83 million are classified ina consistent ontology2,724,000 links to images and 6,300,000 links to external web pagesover 1 billion pieces of information (RDF triples)
  49. DBPedia Lookup Services
  50. Faceted Wikipedia Search based on DBPedia
  51. DBPedia Mobile
  52. Freebasea large collaborative knowledge base consisting of metadatacomposed mainly by its community members
  53. Linked Data on BBCData from WikipediaData from MusicBrainz
  54. Best Buy with GoodRelations <div class="vcard" typeof="gr:LocationOfSalesOrServiceProvisioning" about="#store_1796"> <div class="hours" rel="gr:hasOpeningHoursSpecification"> <li class="day0" typeof="gr:OpeningHoursSpecification" about="#storehours_sun"> <span rel="gr:hasOpeningHoursDayOfWeek" resource="" class="day"> <span property="gr:opens" datatype="xsd:time" content="11:00:00" class="open"> ...
  55. Agenda• World Wide Web• Semantic Web• Semantic Web Tools and Applications• Linking Open Data Social Semantic Web• Open Government
  56. Social Semantic Web a Web of collective knowledge systems, which are able to provide useful information based on human contributions and which get better as more people participate
  57.  Social Web Social  Wikis, blogs, social networks Semantic Web SIOC, DBpedia, Twine World Wide Web Semantic Web URIs, HTML, HTTP RDFS, OWL, SPARQL Syntax Semantic
  58. Vocabularies for SSWFOAF (Friend of a friend)a phrase used to refer to someone that one does not know well, literally, afriend of a friendSIOC (Semantically-Interlinked Online Communities)methods for interconnecting discussion methods such as blogs, forumsand mailing lists to each otherSKOS (Simple Knowledge Organization System)formal languages designed for representation of thesauri, classificationschemes, taxonomies, subject-heading systems, or any other type ofstructured controlled vocabularyMOAT (Meaning Of A Tag)a Semantic Web framework to publish semantically-enriched content fromfree-tagging one
  59. Facebook’s Open Graph Protocolsimple protocol for enabling any web page to become a rich objectin a social graph watch is a friend of is a friend of is a friend of is a friend of watch Myungjin Lee like like cook
  60. In 2010, we extended the social graph, via theOpen Graph protocol, to include 3rd party websites and pages that people liked throughoutthe web. We are now extending the Open Graphto include arbitrary actions and objects createdby 3rd party apps and enabling these apps tointegrate deeply into the Facebook experience.
  61. Social Object cookMyungjin Lee me:cook rdf:type og:title Stuffed Cookies og:image og:url og:description The Turducken of Cookies
  62. Twitter Annotationsto add one or more annotations that represent structured metadataabout the tweet
  63. How to make Annotations on your tweetsFirst element is a type. Every Annotations has a type. Type maps to attribute and value pair.Second element is one or more attribute names with values.
  64. Agenda• World Wide Web• Semantic Web• Semantic Web Tools and Applications• Linking Open Data• Social Semantic Web Open Government
  65. Open Government Data Open By “open”, “open” data is free for anyone to use, re-use and re- distribute. Open Open Data Open Gov Gov By “government data” we mean data Data and information produced orData Gov Data commissioned by government or Gov government controlled entities.
  66. Publishing Open Government DataStep 1: The quickest and easiest way to make data available on theInternet is to publish the data in its raw form (e.g., an XML file of pollingdata from past elections). However, the data should be well-structured likeXML, RDF and CSV.Step 2: Create an online catalog of the raw data so people can discoverwhat has been posted.Step 3: Make the data both human- and machine-readable: • enrich your resources with semantics, metadata, and identifiers; • encode the data using open and industry standards - especially XML - or create your own standards based on your vocabulary; • make your data human-readable by either converting to (X)HTML, or by using real-time transformations through CSS or XSLT. • use permanent patterned and/or discoverable "Cool URIs"; • allow for electronic citations in the form of standardized hyperlinks.
  67. (the United States Government)
  68. (HM Government)
  69. A Timeline of Open Government Data
  70. Data-Gov Wikia project for investigating open government datasets using semantic webtechnologies
  71. Clean Air Status and Trends - Ozone
  72. Code for Americaa non-partisan, non-political 501(c)3 organization founded in2009 to bring web-industry professionals to work with city governmentsin the United States in order to promote openness, participation,and efficiency in municipal governments
  73. SolarCity
  74. DataMarketa privately held Icelandic company that specialises in providing accessto and visually displaying data from public and, to a lesser extent,private institutions and companies
  75. Contents Search on the Semantic Web Dr. Myungjin Lee e-Mail : Twitter : Facebook : SlideShare :
  76. References