linked open data final

8/10/2019 Linked Open Data Final

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Linked Data

Relational Links Identical Links Vocabulary Links

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Use Semantic Web technologies to1. publish structured data on the Web,2. set links between data from one data source

to data within other data sources.


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RLFinder

http://www.visualdataweb.org/relfinder.php


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Linked Data Principles

1. Use URIs as names for things.2. Use HTTP URIs so that people can look up those

names.

3. When someone looks up a URI, provide usefulRDF information.

4. Include RDF statements that link to other URIs sothat they can discover related things.

Tim Berners-Lee 2007http://www.w3.org/DesignIssues/LinkedData.html


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The RDF Data Model

Richard Cyganiak

dbpedia:Berlin

foaf:name

foaf:based_near

foaf:Personrdf:typepd:cygri


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Data objects are identified with HTTP URIs

pd:cygri

Richard Cyganiak

dbpedia:Berlin

foaf:name

foaf:based_near

foaf:Personrdf:type

pd:cygri = http://richard.cyganiak.de/foaf.rdf#cygri dbpedia:Berlin = http://dbpedia.org/resource/Berlin


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Dereferencing URIs over the Web

dp:Cities_in_Germany

3.405.259dp:population

skos:subject

Richard Cyganiak

dbpedia:Berlin

foaf:name

foaf:based_near

foaf:Personrdf:typepd:cygri


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Dereferencing URIs over the Web

dp:Cities_in_Germany

3.405.259dp:population

skos:subject

Richard Cyganiak

dbpedia:Berlin

foaf:name

foaf:based_near

foaf:Personrdf:type

dbpedia:Hamburg

dbpedia:Muenchen

skos:subject

skos:subject

pd:cygri


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Correspondence between thing-URI andsource-URI (slash URIs)

User Agent

Webserver

HTTPGET

RDF303HTTPGET

303 See Other is a way to redirectweb applications to a new URI


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Correspondence between thing-URI andsource- URI (hash URIs)

User Agent

Webserver

HTTP GET RDF


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The Disco Hyperdata Browser


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Content Negotiation Use a generic document URL with RDF and HTML

variants Clients express preferences for formats in Accept

HTTP header Server decides which variant to serve

Generic document: e.g. .../about Format-specific: e.g. .../about.rdf, .../about.html


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Content Negotiation


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Content Negotiation


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Linked Open Data Rating

- Available on the web (whatever format), but withan open licence

- Available as machine-readable structured data

(e.g. excel instead of image scan of a table)

- Non-proprietary format (e.g. CSV instead of excel)

- All the above plus, Use open standards from W3C(RDF and SPARQL) to identify things

- All the above, plus: Link your data to other peoplesdata

(Berners-Lee, 2010)


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W3C Linking Open Data Project

Community project with W3C support to publish existing open license datasets as Linked Data on the Web in

RDF interlink things between different data sources Began early 2007


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LOD Datasets on the Web: May 2007

Over 500 million RDF triplesAround 120,000 RDF links between data sources


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LOD Datasets on the Web: September 2011

Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lodcloud.net/


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Types of Data in the Linking Open Data Cloud

http://www4.wiwiss.fu-berlin.de/lodcloud/state/ (Sept 2010)


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Beautiful Applications over Raw Data

Source: Berners-Lee, TED 2009


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Applications

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links

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SearchEngines

Linked DataMashups

Linked DataBrowsers

What can I do with this?


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Linked Data Browsers

Tabulator Browser (MIT, USA)Disco Hyperdata Browser (FU Berlin, DE)

OpenLink RDF Browser (OpenLink, UK)

Zitgist RDF Browser (Zitgist, USA)

Humboldt (HP Labs, UK)

Fenfire (DERI, Irland)Marbles (FU Berlin, DE)


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Linked Data Mashups

Domain-specific applications using Linked Data from the Web A Mashup is a way of combining related data into a pictorial

form using Socially Rich computing technology to make thedata easy to read and understand

ChartsGraphs

WebsitesMaps

Tables

MoviesAJAX Rich Applications


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DBtune Slashfacet Visualizes music-related Linked Data Uses LastFM, MySpace, and BBC data


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Web of Data Search Engines

Falcons (IWS, China) Sindice (DERI, Ireland) MicroSearch (Yahoo, Spain) Watson (Open University, UK) SWSE (DERI, Ireland) Swoogle (UMBC, USA)


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Falcons


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Roles in the Linked Data Scenario Data Publisher

1. Publish data itself2. Set RDF links to other

data items describing thesame real-world entity.

3. Reuse terms fromexisting vocabularies orset links to relatedschemata.

4. Publish metadata about provenance timeliness data license

Client Application1. Map data into single

schema.

2. Smush data fromdifferent sources aboutreal-world entity.

3. Resolve inconsistenciesin the data.

4. Keep track of informationprovenance and lineage.

5. Explain fusion process.

CREATE LINKS owl:sameAsBETWEEN a FROM dbpedia AND b FROM factbookRESTRICT a TO { ?a rdf:type dbpedia-owl:Country }

METRIC { STRING_SIMILARITY(a/rdfs:label, b/rdfs:label), NUM_SIMILARITY(a/p:populationEstimate,

b/factbook:population_total),

NUM_SIMILARITY(a/p:areaKm, b/factbook:area_total) }THRESHOLDS MATCH 0.9 VERIFY 0.7;

# Metadata and Licensing Information rdf:type foaf:Document ;

dc:publisher ;dc:date "2007-07-13"^^xsd:date ;dc:rights .

# The Document Content rdf:type foaf:Person;

foaf:name "Empire, Alec" ;dbpedia-owl:associatedBand dbpedia:Atari_Teenage_Riot ;

# TriG Representation of three Named Graphs :G1 { :Monica ex:name "Monica Murphy" .

:Monica ex:homepage .:Monica ex:email .}

:G2 { :Monica rdf:type ex:Person .

:Monica ex:hasSkill ex:Programming }

:G3 { :G1 swp:assertedBy _:w1 ._:w1 swp:authority :Chris ._:w1 dc:date "2003-10-02"^^xsd:date .

:G2 swp:quotedBy _:w2 ._:w2 swp:authority :Chris ._:w2 dc:date "2003-09-03"^^xsd:date . }


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How can we publish Linked Data?

Serving Linked Data as Static RDF/XML Files Serving Linked Data as RDF Embedded in HTML Files Serving RDF and HTML with Custom Server-Side

Scripts Serving Linked Data from Relational Databases Serving Linked Data from RDF Triple Stores

Serving Linked Data by Wrapping Existing Applicationor Web APIs


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Linked Data Platforms and Tools

Linked Data Publishing Platforms D2R server Triplify Talis platform Kasabi Pubby Paget etc.

Linked Data/RDF Editors and Validators Hyena Vapour


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Linked Data Tools

Data Access Tools LDspider, SQUIN, Linked Data Client Libraries

Identity Resolution Tools

SILK, LIMES Data Translation Tools

R2R Mapping Framework


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Future of Linked Data Linked Data : The Next Big Wave or Another Tech Fad? Future SEO : Linked Open Data (LOD) Is Linked Data the future of data integration in the enterprise? Linked Data and Internet of Things


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Dbpedia Mobile Location-centric DBpedia

client applicationfor mobile devices

Geospatial entry pointinto the Web of Data

Starts with DBpedia,Revyu and Flickr data

http://mes-semantics.com/DBpediaMobile/


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DBpedia Mobile

Consists of a map view, the Marbles Linked Data Browserand a GPS-enabled launcher application.

Renders a map containing information about nearby locationsfrom the DBpedia dataset.

Geographic locations are currently available for 300,000of DBpedia's 2.18 million things.



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Dbpedia Mobile Usage

Provides browser-based area map that indicates the user's positionand nearby DBpedia resources with appropriate labels and icons.

Clicking on a resource brings up a summary view of the selecteditem generated by the Marbles Linked Data Browser.

The view may include short text describing the resource , an image,a link to the resource's foaf:homepage and reviews from the Revyurating site if existent.

If the displayed data contains RDF links into other datasets, the user

may click them to obtain a full details view of the referencedresource.

In this manner, the user can navigate from the DBpedia dataset intoother interlinked datasets



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Credits

DBpedia Mobile's Map View uses the following components: Core DBpedia datasets (labels, geo -coordinates and categories) are

pre-loaded into Marbles' Sesame 2.1 MySQL store Map tiles provided by OpenStreetMap

Jibbering RDF Parser to parse RDFXML map data results GeoLite City for IP Lookup Google Maps API GxMarker V2 Prototype JavaScript framework



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RelFinder

Interactive Relationship Discovery in RDF Data Developed and maintained by http://www.visualdataweb.org. It extracts and visualizes relationships between given objects

in RDF data and makes these relationships interactivelyexplorable.

Highlighting and filtering features support visual analysis bothon a global and detailed level.

The RelFinder is based on the open source framework AdobeFlex, easy-to-use and works with any RDF dataset thatprovides standardized SPARQL access.



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RelFinder

The RelFinder can easily be configured to work with differentRDF datasets. It can even be called from remote to access a specific dataset

and/or certain objects.

The RelFinder can also be more deeply integrated with ourproject. URLs can also be composed dynamically to integrate the

RelFinder with our tool.

Integration requiresRelFinder.swf - the Flash file that is executed config/Config.xml - the file that configures the RelFinder for the dataset(s) config/examples.xml - a file with examples



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RLFinder



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Thank You

References Linking Open Data Project Wiki

http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/

LinkingOpenData Tutorial on How to Publish Linked Data on the Web

http://www4.wiwiss.fu-berlin.de/bizer/pub/LinkedDataTutorial/

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