openhpi 1.7 - applications in the web of data
DESCRIPTION
Free online Lecture "Semantic Web Technologies" at OpenHPI. Visit the Course website, registration is free. You will find the lecture recordings as mp3 and also as video at https://openhpi.de/course/semanticwebTRANSCRIPT
Dr. Harald Sack
Hasso Plattner Institute for IT Systems Engineering
University of Potsdam
Spring 2013
Semantic Web Technologies
This file is licensed under the Creative Commons Attribution-NonCommercial 3.0 (CC BY-NC 3.0)
Lecture 1: The Web of Data 07: Applications in the Web of Data
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
Lecture 1: The Web of Data
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Open HPI - Course: Semantic Web Technologies
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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07: Applications in the Web of Data OpenHPI - Course Semantic Web Technologies - Lecture 1: The Web of Data
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
4 Linked Data□ Linked Open Data (LOD) denote publicly available (RDF) Data in the Web, identified via
URI and accessable via HTTP. Linked data link to other data via URI.
Semantic Web Technologies Applications on the Web of Data
The ,Web of Data‘
• >31 billion facts
• >500 million links (Oct. 2011)
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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http://www.bbc.co.uk/music
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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What is so special about the BBC Music Website?
• Information is dynamically aggregated from external, publicly available data (Wikipedia, MusicBrainz,...)
• no Screen Scraping
• no specialized API
• data available als Linked Open Data
• data access via simple HTTP Request
• data is always up-to-date without manual interaction
Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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• Refine ,jaguar‘ CAR or ANIMAL or OPERATINGSYSTEM etc. ?Refine: CAR
Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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•Name: Jaguar E Type•Category: Car•...• ConstructionYear <Integer>• technicalParameter• CylinderCapacity <Integer>• Power <Integer>• ...
• ...
Knowledge Representation(Ontology, Linked Data)
Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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•Refine ,2000‘ ConstructionYear or technicalParameter ?Refine: ConstructionYear
•Name: Jaguar E Type•Category: Car•...• ConstructionYear <Integer>• technicalParameter• CylinderCapacity <Integer>• Power <Integer>• ...
• ...
Knowledge Representation(Ontology, Linked Data)
Search Engines - Document Retrieval
•Search Engine Query String: “Jaguar of 2000“
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
9Search Engines - Document Retrieval
• General Problems:
• correct interpretation of query string
• correct identification of entities
• automatic disambiguation
• usability
• personalization
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Search Engines - Fact Retrieval
•Query String: “Where can I fill up the tank at a considerable discount?“
Answer : - Hohenfelden, xy-Str. 32 -> Super leaded, 1,99 € - fuel-efficient route will be passed to navigation - drive only at half throttle for saving fuel…
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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dbpedia-owl:mission
dbpedia:Neil_Armstrong
dbpedia:Apollo_11dbpedia-owl:mission
category:Apollo_program
dcterms:subject
dbpedia:Apollo_13
dcterms:subject
yago:Space_accidents_and_incidents
rdf:type
rdf:type
dbpedia:Space_Shuttle_Challenger
dbpedia-owl:mission
dbpedia:Buzz_Aldrin
dbpedia:Michael_Collins
Search Engines - Exploratory Search
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Intelligent Agents in the Semantic Web
User
retrieval service(e.g. Google)
WWW documents
presentation service(e.g. Firefox)
WWW
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Intelligent Agents in the Semantic Web
User
retrieval service(e.g. Google)
WWW documents
presentation service(e.g. Firefox)
WWW
WWW documents
SemanticWeb
User
personalassistant
intelligentinfrastructure
services
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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3 Generations of Web Documents
staticweb pages
HTML / CSS
1. Generation
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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3 Generations of Web Documents
staticweb pages
HTML / CSS
1. Generation
interactiveweb pages
dynamicweb pages
JavaScript / Applets
Data Base AccessTemplate-based
Generation
2. Generation
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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3 Generations of Web Documents
staticweb pages
HTML / CSS
1. Generation
interactiveweb pages
dynamicweb pages
JavaScript / Applets
Data Base AccessTemplate-based
Generation
2. Generation
adaptiveweb pages
virtualweb pages
User ModelsMachine Learning
Online Layout
NetbotsInformation ExtractionPresentation Planning
3. Generation
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
14 Toolbox for the Semantic Web
•Standardized languages to express semantics of information content in the Web (XML/XSD, RDF(S), OWL, RIF)
•Tools to use semantic information in the Web (RDFa, GRDDL, ...)
•Various fields of computer science:
• artificial intelligence
• linguistics
• cryptography
• data bases
• theoretical computer science
• computer architecture
• software engineering
• systems theory
• computer networks
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Lecture 2: Basic Architecture of the Semantic Web
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