Download - Short guide to the Semantic Web
![Page 2: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/2.jpg)
THE SEMANTIC WEB
WHAT IS THE GOAL?
WHAT ARE THE BUILDING BLOCKS?
HOW DO WE CREATE THE GRAPH?
WHY LINKED DATA?
SHORT INTRO TO ONTOLOGIES
![Page 3: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/3.jpg)
What’s in a page ? And in a link ?
?
?
?
![Page 4: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/4.jpg)
VISION FOR THE WEB
TIM BERNERS-LEE, THE 1ST WORLD WIDE WEB CONFERENCE, GENEVA, MAY 1994:
DESCRIBE DOCUMENTS IN MACHINE READIBLE FORM CREATE MEANINGFUL LINKS (“RELATIONSHIP VALUES”) “ONLY WHEN WE HAVE THIS EXTRA LEVEL OF SEMANTICS
WILL WE BE ABLE TO USE COMPUTER POWER TO HELP US EXPLOIT THE INFORMATION TO A GREATER EXTENT THAN OUR OWN READING.”
![Page 5: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/5.jpg)
Aims of the Semantic Web
BRIDGING THE GAP BETWEEN A WEB OF DOCUMENTS TO A WEB OF DATA, WITH TYPED OBJECTS AND TYPED RELATIONSHIPS ADDING MACHINE-READABLE METADATA TO EXISTING CONTENT, SO THAT INFORMATION CAN BE PARSED, QUERIED, REUSED
![Page 6: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/6.jpg)
Aims of the Semantic Web
DEFINING SHARED SEMANTICS FOR THIS METADATA TO ALLOW INTEROPERABILITY BETWEEN APPLICATIONS AND FOR ADVANCED PURPOSES, SUCH AS REASONING ENABLING MACHINE-READABLE KNOWLEDGE AT WEB SCALE, MAKING INFORMATION MORE EASY TO FIND AND PROCESS
![Page 7: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/7.jpg)
The Semantic Web, circa 2010
MOST STANDARDISATION WORK IS DONE IN THE W3C:
HTTP://WWW.W3.ORG/
INCUBATOR GROUPS, WORKING GROUP, INTEREST GROUPS:
WGS FOR SPARQL, RDB2RDF, RIF, ETC. HCLS IG, SOCIAL WEB XG, ETC.
![Page 8: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/8.jpg)
Name everything
![Page 9: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/9.jpg)
Identifying resources with URIs
URIS ARE USED TO IDENTIFY EVERYTHING IN A UNIQUE AND NON-AMBIGUOUS WAY NOT ONLY PAGES (AS ON THE CURRENT WEB), BUT ANY RESOURCE (PEOPLE, DOCUMENTS, BOOKS, INTERESTS, ETC.) A URI FOR A PERSON IS DIFFERENT FROM A URI FOR A DOCUMENT ABOUT THE PERSON, BECAUSE A PERSON IS NOT A DOCUMENT! e.g. http://deri.ie/user/maciej-dabrowski
e.g. http://deri.ie/content/modelling-preference-relaxation-e-commerce
![Page 10: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/10.jpg)
Defining assertions with RDF
• URIS IDENTIFY RESOURCES: • WE USE RDF (RESOURCE DESCRIPTION
FRAMEWORK) TO DEFINE ASSERTIONS ABOUT THESE RESOURCES
• RDF IS A DATA MODEL; A DIRECTED, LABELED GRAPH USING URIS
• RDF IS BASED ON TRIPLES: – <SUBJECT> <PREDICATE> <OBJECT>.!
![Page 11: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/11.jpg)
Simple triples
Maciej Dabrowski
MDabrowski-lecture3
author
Semantic_Web
Introduction to the Semantic Web
title
subject
![Page 12: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/12.jpg)
Use Uris
http://example.org/maciej-dabrowski
http://example.org/MDabrowski-lecture3
http://example.org/author
http://example.org/Semantic_Web
Introduction to the Semantic Web
http://example.org/title
http://example.org/subject
![Page 13: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/13.jpg)
Abbreviating uris
PREFIX ex: http://example.org/# ex:maciej = <http://example.org/#maciej>
ex:maciej-dabrowski
ex:MDabrowski-lecture3
ex:author
ex:Semantic_Web
Introduction to the Semantic Web
ex:title
ex:subject
![Page 14: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/14.jpg)
Reuse existing vocabularies
PREFIX dct: http://purl.org/dc/terms/
http://deri.ie/user/maciej-dabrowski
http://example.org/MDabrowski-lecture3
dct:creator
http://dbpedia.org/resource/Semantic_Web
Introduction to the Semantic Web
dct:title
dct:subject
![Page 15: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/15.jpg)
RDF by example !!@prefix dct: <http://purl.org/dc/terms/> . !<http://example.org/dm110-semweb>!!dct:title “Introduction to the Semantic Web” ; !
!dct:author <http://www.deri.ie/users/maciej-dabrowski> ; !!!dct:subject <http://dbpedia.org/resource/Semantic_Web> .!
![Page 16: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/16.jpg)
RDFA
A WAY OF EMBEDDING RDF IN (X)HTML DOCUMENTS:
ONE PAGE FOR BOTH HUMANS AND MACHINES DON’T NEED TO REPEAT YOURSELF INTRODUCING NEW XHTML ATTRIBUTES
CURRENT WORK IS ONGOING ON RDFa 1.1: FOR PROFILES, ETC.
![Page 17: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/17.jpg)
RDFa example
![Page 18: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/18.jpg)
Triples are everywhere!
10/06/2013
SUBJECT
PREDICATE OBJECT
PREDICATE OBJECT OBJECT …
![Page 19: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/19.jpg)
![Page 20: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/20.jpg)
Defining semantics with ontologies
• RDF PROVIDES A WAY TO WRITE ASSERTIONS ABOUT URIS
• WHAT ABOUT THE SEMANTICS OF THESE ASSERTIONS, E.G. TO STATE THAT HTTP://XMLNS.COM/FOAF/0.1/KNOWS IDENTIFIES AN ACQUAINTANCE RELATIONSHIP?
• ONTOLOGIES PROVIDE COMMON SEMANTICS FOR RESOURCES ON THE SEMANTIC WEB
![Page 21: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/21.jpg)
Ontologies consist mainly of classes and properties – :Person a rdfs:Class .!– :father a rdfs:Property .!– :father rdfs:domain :Person .!– :father rdfs:range :Person .!
:Maciej
:Mark
:father
:Persona
:Persona
![Page 22: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/22.jpg)
Notable ontologies
SOCIAL NETWORKS AND SOCIAL DATA:
FOAF, SIOC TAXONOMIES AND CONTROLLED VOCABULARIES:
SKOS, MOAT
![Page 23: Short guide to the Semantic Web](https://reader033.vdocuments.mx/reader033/viewer/2022052822/554bc3f2b4c90530298b5328/html5/thumbnails/23.jpg)
Linked Data