Semantic Web

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Semantic Web

• World Wide Web ConsortiumKeio University/Environm
  ental InformationTatsuya Hagino

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Semantic Webby Tatsuya Hagino

• Table of contents
• Semantic Web
• Development of Web
• Tim Berners-Lee's Goal of Web
• Semantic Web is not HTML Web
• What Semantic Web can do - Example -
• Transation and Interaction
• Semantic Web is Metadata Web
• Semantic Web Architecture

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Development of Web

• HTML
• Separate structure and presentation
• Accessibility
• HTML 4.01 is the current and final version of
  HTML
• HTML 4.01 has three DTDs
• Strict
• Transitonal
• Frameset
• XML
• New Standard for Internet Document
• Easy to process
• Mixing documents using namespace
• Generalize HTML ideas
• Stylesheet XSL, XSL-T
• Hyperlink XLink, XPointer
• XML Schema for more powerful constraint
• XML base Web document
• XHTML
• MathML

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Tim Berners-Lee's Goal of Web

• Human to human communication
• Information available for anytime, anywhere and
  anyone.
• HTML
• Human to machine communication
• Machine solves problems
• Semantic Web

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Semantic Web is not HTML Web

• HTML documents are for human to read and
  understand.
• Metadata in Semantic Web is for machine to
  process and understand.
• Metadata
• data for data
• RDF (Resource Description Framework) is metadata
  of Web
• Metadata history
• PICS (Platform for Internet Content Selection)

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What Semantic Web can do - Example -

• Plan a trip to Boston
• Current Web
• Use search engine to list airlines.
• Check each airline for suitable flights, and
  decide the airline company.
• Use search engine to list travel agencies.
• Check each travel agency for price of the ticket,
  decide the travel agency, and actually make a
  reservation.
• Figure out how to buy the ticket (how to pay).
• Check Narita express and reserve one.
• Use search engine to list hotels at Boston.
• Check each hotel, decide the hotel and make a
  reservation.
• Print out the information about flight, Narita
  express and hotel.
• Semantic Web
• Ask to list available flights to Boston for any
  airline with low price. Pick one and it
  automatically reserve the flight.
• It also reserve Narita express automatically.
• Then, it automatically search hotels at Boston
  which is convenient for the business. Pick one
  and it automatically reserve the hotel.
• All the information is put into your handheld
  device.
• It may also put restaurant phone numbers and
  other useful information into the handheld
  device.

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Transation and Interaction

• Current Web
• HTML form
• CGI
• HTML result page
• Query result can only be understandable by human.
  
• Semantic Web
• Metadata query (HTML form may generate it)
• Metadata result (with HTML for human readability)
  
• Machine can understand and further process

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Semantic Web is Metadata Web

• Machine communication each other
• Apply the design principle of the Web
• Interoperability
• Evolution
• Decentralization
• Use RDF for metadata
• Use RDF Schema for basic type definition (class
  hierarchy)
• Use Ontology to cope with different vocabulary

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Semantic Web Architecture