The Web = The Internet + links + documents or The Web = The Internet + http + html Image from - http://www.bbc.co.uk/blogs/radiolabs/s5/linked-data/s5.html
Current Web• HTTP protocol is used for accessing and exchanging web data• HTML language is used for creating web pages• Machines can read the language• But they don’t “understand” the content
People and the Web• But people aren’t interested in documents!• People are interested in things (objects)• People can extract knowledge from web pages• Machines can’t!• So we need a way to help machines help us!
The Web as we know it…is not the Web thatTim Berners Lee wanted
Social Machines“Computers can help if we usethem to create abstract socialmachines on the Web : processesin which the people do the creativework and the machine does theadministration…” Berners-Lee, Weaving the Web, 1999
Semantic Web• The idea of the Semantic Web aims at converting the current web of unstructured documents into a web of data• Tim Berners Lee defines the Semantic Web as "a web of data that can be processed directly and indirectly by machines."
Technologies - RDF• RDF – Resource Description Language – Triples – Subject, Predicate, Object,• “Stefan works at DERI” – Stefan – Subject – Works at – Predicate – DERI - Object
URI• But Stefan can be described by a URIhttp://www.deri.ie/fileadmin/scripts/foaf.php?id=12• And DERI can be described by it’s homepagehttp://www.deri.ie• So we can rewrite it in English ashttp://www.deri.ie/fileadmin/scripts/foaf.php?id=12 works at http://www.deri.org/
SPARQL• SPARQL - SPARQL Protocol and RDF Query Language• Think of it as SQL for RDF• But because RDF data is more “expressive” – SPARQL allows for more complicated queries• Give me all artists signed to Elektra Records that are from the genre Rock
Ontologies• Ontology define the terms used to describe and represent an area of interest – Concepts (classes) – Relationships (subclasses) – Properties (attributes)• FOAF– Friend of a Friend• SIOC – Semantically Interlinked Online Communities• DC – Dublin Core• SSN – Semantic Sensor Network
Ontologies• Ontologies are used to describe certain areas of interest• For example FOAF – describes relationships between people• SIOC – Describes groups and creates interoperability between blogs/forums/social networks• SSN ontology describes sensor stations/sensor nodes and their sensing capabilities
Linked Data• Linked Data is about using the Web to connect related data that wasnt previously linked• Without Linked Data there is no Web of Data• For example - DBPedia – is a Linked Data version of Wikipedia which recreates the data on Wikipedia and linked it to other data sources (Geonames)
Is publishing data enough? http://lab.linkeddata.deri.ie/2010/star-scheme-by-example/
Citizen Sensing• Networks of Humans with Sensors• Humans process data (a positive and a negative)• Sensor nodes generally do not process data• But using mobile devices’ sensors we can add an additional layer to human in the loop sensing
Semantic Sensing• Describing Sensors with Semantic Technologies• SSN Ontology and adding reasoning on top of that• For example – if light temperature is reading low light levels and the humidity sensor is reading high humidity then rain is likely!
Annotating Sensor data to Social web posts!• Define a standard way for attaching mobile sensor data to social web content• Twitter Annotations• Extend SIOC ontology and align with SSN Ontology
Why?• Natural Disaster Management• Traffic Reporting Applications• All kinds of crowdsourcing applications• Crowdsourcing, citizen sensing and sensor web technologies for public and environmental health surveillance and crisis management: trends, OGC standards and application examples - http://www.ij- healthgeographics.com/content/10/1/67/abstrac t
References• Hand drawn slide used with permission of John Breslin - http://www.slideshare.net/Cloud/the-social- semantic-web-1328494• Other slides from John Breslin’s slideshare also used (LOD cloud images)• BBC Presentation on Linked Data - http://www.bbc.co.uk/blogs/radiolabs/s5/linked- data/s5.html• BBC Blog Post about using Sem Web Technologies for World Cup 2010 - http://www.bbc.co.uk/blogs/bbcinternet/2010/07/bbc _world_cup_2010_dynamic_sem.html