Your SlideShare is downloading. ×
0
Semantic Web                                 TechnologiesLecture 2: Semantic Web - Basic Architecture I                   ...
2Lecture 2: Semantic Web - Basic Architecture I                      Open HPI - Course: Semantic Web Technologies    Seman...
2. Semantic Web - Basic Architecture    Part 13    Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, U...
4    01 How to Identify Things? - URIsOpen HPI - Course: Semantic Web Technologies - Lecture 2: Semantic Web Basic Archite...
What is this?5    Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
What`s the difference?6    Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
Semiotic Triangle7                                                      Concept                           symbolizes      ...
Semiotic Triangle7                                                    shared concept                                      ...
The Designator in the Web8    Uniform                                                                                  □ d...
Uniform Resource Identifier9    ■ A Uniform Resource Identifier (URI) defines a simple and extensible schema      for worldw...
URI, Resource and                                                                                                 Resource...
Representation and     Presentation11     Metadata:      Content-type: text/html     Data:                                ...
HTTP Request / Response12                                                                                                 ...
HTTP Request / Response13                                               Browser sends HTTP Request                        ...
Designator and Designatum                                                                           Designatum14          ...
2. Semantic Web Basisarchitektur     2.1 Uniform Resource Identifier - URI15     Bezeichner und Bezeichnetes               ...
16                                                                                                 Johannes Osterhoff::   ...
Designator and Designatum17          The distinguishing characteristic of [information] resources          is that all of ...
18                                       Metadata     Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut...
URI, Ressource and     Metadata19               URI                  http://www.tour-eiffel.fr/index.html                 ...
Uniform Resource Identifier20   ■ URI combines     Address       □ Address (Locator)              □ Uniform Resource Locato...
URI - Generic Syntax21     ■ US-ASCII Encoding     ■ Percent Encoding for reserved characters, or characters that do not e...
URI - Generic Syntax22       URI = schema"://"[userinfo"@"]host[:port][path]["?"query]["#"fragment]     ■ schema: e.g. htt...
URIs in the Semantic Web23     ■What if a URI for a resource does not exist?     ■ Define a URI by yourself:        □ avoid...
24Lecture 2: Semantic Web - Basic Architecture I                       Open HPI - Course: Semantic Web Technologies     Se...
24Lecture 2: Semantic Web - Basic Architecture I                       Open HPI - Course: Semantic Web Technologies     Se...
Upcoming SlideShare
Loading in...5
×

OpenHPI 2.1 - How to Identify Things - URIs

976

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
976
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
72
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "OpenHPI 2.1 - How to Identify Things - URIs"

  1. 1. Semantic Web TechnologiesLecture 2: Semantic Web - Basic Architecture I 01: How to Identify Things? - URIs Dr. Harald Sack Hasso Plattner Institute for IT Systems Engineering University of Potsdam Spring 2013 This file is licensed under the Creative Commons Attribution-NonCommercial 3.0 (CC BY-NC 3.0)
  2. 2. 2Lecture 2: Semantic Web - Basic Architecture I Open HPI - Course: Semantic Web Technologies Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  3. 3. 2. Semantic Web - Basic Architecture Part 13 Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  4. 4. 4 01 How to Identify Things? - URIsOpen HPI - Course: Semantic Web Technologies - Lecture 2: Semantic Web Basic Architecture I Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  5. 5. What is this?5 Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  6. 6. What`s the difference?6 Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  7. 7. Semiotic Triangle7 Concept symbolizes refers to Symbol Object stands for „apple“ Ogden, Richards: Semiotic Triangle, 1923 Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  8. 8. Semiotic Triangle7 shared concept Concept symbolizes refers to Symbol Object stands for „apple“ Ogden, Richards: Semiotic Triangle, 1923 Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  9. 9. The Designator in the Web8 Uniform □ different types of resource identifiers all constructed according to a uniform schema Resource □ whatever may be identified via URI Identifier □ to distinguish one resource from another Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  10. 10. Uniform Resource Identifier9 ■ A Uniform Resource Identifier (URI) defines a simple and extensible schema for worldwide unique identification of abstract or physical resources (RFC 3986). ■ Resource can be every object with a clear identity (according to the context of the application) □ as e.g., web pages, books, locations, persons, relations among objects, abstract concepts, etc. ■ The concept of URI is already established in various domains, as e.g., □ the Web (URL, PRN, pURL), □ Books and publications (ISBN, ISSN), □ Digital Object Identifier (DOI) Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  11. 11. URI, Resource and Resource Representation10 URI http://www.tour-eiffel.fr/index.html identifies representation represents (stands for) Metadata: Content-type: text/html Data: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Le site officiel de la Tour Eiffel</title> ... </html> Eiffel Tower Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  12. 12. Representation and Presentation11 Metadata: Content-type: text/html Data: defines <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> Presentation <head> <title>Le site officiel de la Tour Eiffel</title> ... </html> Representation Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  13. 13. HTTP Request / Response12 Browser sends HTTP Request GET http://www.tour-eiffel.fr/index.html HTTP/1.1 Host: www.tour-eiffel.fr Accept: text/htmlUser clicks Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  14. 14. HTTP Request / Response13 Browser sends HTTP Request Web Server processes request GET http://www.tour-eiffel.fr/index.html HTTP/1.1 Host: www.tour-eiffel.fr Accept: text/html Browser interprets representation and displays presentation Web Server sends HTTP Response HTTP/1.1 200 OK Content-Length: 3134 Web Server of Content-Type: text/html; charset=utf-8 www.tour-eiffel.fr <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Le site officiel de la Tour Eiffel</title> ... </html> Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  15. 15. Designator and Designatum Designatum14 Designator ≠ The web page describes (designates) the Eiffel Tower The Eiffel Tower is described (designated) by the web page Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  16. 16. 2. Semantic Web Basisarchitektur 2.1 Uniform Resource Identifier - URI15 Bezeichner und Bezeichnetes René Magritte: Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam La trahison des images (1928)
  17. 17. 16 Johannes Osterhoff:: Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam La trahison des pommes (2011)
  18. 18. Designator and Designatum17 The distinguishing characteristic of [information] resources is that all of their essential characteristics and can be conveyed in a message. W3C: Architecture of the World Wide Web, Volume One □ A resource can be described (designated) via Metadata □ Even if the resource itself cannot be delivered from the web server, probably its representation might be available that describes the resource sufficiently. Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  19. 19. 18 Metadata Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  20. 20. URI, Ressource and Metadata19 URI http://www.tour-eiffel.fr/index.html identifies Resource: Eiffel Tower Representation describes (designates) Metadata: Content-type: text/html Data: <!DOCTYPE HTML PUBLIC "-//W3C//DTD represents HTML 4.01 Transitional//EN" Information about Resource: "http://www.w3.org/TR/html4/loose.dtd"> the Eiffel Tower Eiffel Tower <html> (stands for) <head> Metadata <title>Le site officiel de la Tour Eiffel</title> ... </html> Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  21. 21. Uniform Resource Identifier20 ■ URI combines Address □ Address (Locator) □ Uniform Resource Locator (URL, RFC 1738) □ denotes, where a resource can be found in the Web by stating its primary access mechanism □ might change during life cycle □ Identity (Name) Name □ Uniform Resource Name (URN, RFC 2141) □ persistent identifier for a Web resource □ remains unchanged during life cycle Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  22. 22. URI - Generic Syntax21 ■ US-ASCII Encoding ■ Percent Encoding for reserved characters, or characters that do not exist in US-ASCII encoding existieren pct-encoded = "%" HEXDIG HEXDIG ■ Reserved characters with special function reserved = gen-delims / sub-delims gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@“ sub-delims = "!" / "$" / "&" / "" / "(" / ")" / "*" / "+" / "," / ";" / "=" ■ Permitted characters unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~" ■ Extension to Universal Character Code (Unicode/ISO 10646) □ Internationalized Resource Identifier (IRI, RFC 3987) e.g.: Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  23. 23. URI - Generic Syntax22 URI = schema"://"[userinfo"@"]host[:port][path]["?"query]["#"fragment] ■ schema: e.g. http, ftp, mailto,... ■ userinfo: e.g. username:password ■ host: e.g. Domain-Name, IPv4/IPv6 Address ■ port: e.g. :80 for standard http port ■ path: e.g. path in file system of WWW server ■ query: e.g. parameters to be passed over to applications ■ fragment: e.g. determines a specific fragment of a document Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  24. 24. URIs in the Semantic Web23 ■What if a URI for a resource does not exist? ■ Define a URI by yourself: □ avoid overlaps  use your own website □ enables documentation at the same place ( Content Negotiation) ■ Separate URI for resource (Designatum) and its documentation (Designator) via URI references (i.e. via "#" fragments) or Content Negotiation z.B.: http://hpi.uni-potsdam.de/harald_foaf.rdf#me Sauermann, Cyganiak: Cool URIs for the Semantic Web, W3C Interest Group Note 03 December 2008, http://www.w3.org/TR/cooluris/ Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  25. 25. 24Lecture 2: Semantic Web - Basic Architecture I Open HPI - Course: Semantic Web Technologies Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  26. 26. 24Lecture 2: Semantic Web - Basic Architecture I Open HPI - Course: Semantic Web Technologies Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×