CLODA: A Crowdsourced Linked Open Data Architecture

Dagstuhl Seminar 10042, Demetris Zeinalipour, University of Cyprus, 26/1/2010

1 © Larkou, Metochi, Chatzimilioudis and Zeinalipour-Yazti, Mobisocial'13, Milan, Italy

First IEEE Intl. Workshop on Mobile Data Management, Mining and Computing on Social Networks (MobiSocial), co-located with IEEE MDM'13, June 3, 2013, Milan, Italy.

CLODA: A Crowdsourced Linked Open Data Architecture

Georgios Larkou, Julia MetochiGeorgios Chatzimilioudis andDemetrios Zeinalipour-YaztiData Management Systems Laboratory

Department of Computer ScienceUniversity of Cyprus

http://dmsl.cs.ucy.ac.cy/


3Presenter: Demetris Zeinalipour, http://dmsl.cs.ucy.ac.cy/

Crowdsourcing Definitions• Crowdsourcing = Crowd + Outsourcing

– Jeff Howe (2006). "The Rise of Crowdsourcing". Wired.

• Definition from Wikipedia:– "Crowdsourcing refers to a distributed

problem-solving model in which a crowd of undefined size is engaged in the task of solving a complex problem through an open call"

“Crowdsourcing with Smartphones”, Georgios Chatzimiloudis, Andreas Konstantinidis, Christos Laoudias, Demetrios Zeinalipour-Yazti, IEEE Internet Computing, Special Issue: Sep/Oct 2012 - Crowdsourcing, May 2012. IEEE Press, Volume 16, Pages: 36-44, 2012.



Crowdsourcing StakeHoldersOpen Call (Task)

Solutions

RewardsRequester

(Crowdsourcer)

Workers(Solvers)Platform



Crowdsourcing Incentives• Tangible (Monetary) Incentives

– Cash, Credit or Gifts (MTurk, Kickstarter)– Unintended or as-a-by-product (reCaptchas)

• Ethical Incentives– Socialize & Fun – Earn Prestige– Altruism – Learn something New

• Usually a combination of several incentives



CLODA Motivation

Closed Data: Web 2.0 APIs (Google,

Twitter, Facebook)

VerificationReward

Collect

Sensor / Geo Data

CLODA (LOD)

Linked Open Data (LOD) (Freebase, DBPedia)

CLODA Prototype

Collect & Link Open and Close Data with smartphones through an open call for ethical benefit

a

b

c

d



Linked Open Data (LOD)• Linked data refers to web accessible data

(HTTP/URI addressable) that is structured (RDF) to allow computer link and query (SPARQL) the data [ aka 4 principles ]

• Conceived by Tim Berners-Lee and realized by the Semantic Web Community.– Tim Berners-Lee (2006). "Linked Data—Design Issues". W3C.

• Linked Open Datasets (LOD): – DBPedia (3.6M things describing Wikipedia)– GeoNames (describing 7.5M Geographic features)– YAGO & YAGO2 (combining Wikipedia, GeoNames and others)– Freebase (39M things - Google's LOD project!)– FOAF (describing People – Relationships –Open Social Net!)



Traditional LOD (RDF)• DBPedia Example: LOD describing 3.64M

Wikipedia things out of which 1.83M are classified in a consistent ontology– 416,000 persons, 526,000 places, 106,000 music albums,

60,000 films, 17,500 video games, 169,000 organizations, 183,000 species and 5,400 diseases

Infobox example



LOD the Google (JSON) Way!• Freebase Example: another LOD by Google.

Instances Relationships



LOD is Interlinked & AnnotatedLOD is interlinked, e.g., Freebase points to Dbpedia

predicates …

http://dbpedia.org/page/Manchester



LOD is Highly Interlinked!

http://www.stateofsearch.com/search-in-the-knowledge-graph-era/



LOD can be Queried!

MQL Queries

Resembles Xpath Querying

LOD can be queried!, e.g., Freebase with MQL Queries (JSON encoded like Web2.0 APIs)



CLODA Motivation


Twitter, Facebook)

VerificationReward

Collect

Sensor / Geo Data

CLODA LOD


CLODA Prototype




Web1.0: The Unstructured Webhttp://books.google.com/

(content in HTML only apprehensible to

User)



Web2.0: The Structured but Closed Webhttps://www.googleapis.com/books/v1/volumes?q=databases

content in XML/JSON apprehensible to Computer

This web is closed: Requires Keys to access (OAUTH) and has download quotas



In fact, Web2.0 Services are omnipresent!(Google, Twitter, Facebook, Youtube, Linkedin, …)

https://code.google.com/apis

http://www.programmableweb.com/ - 7800 APIs!!! + 6800 Mashups!

Web2.0: The Structured but Closed Web

quota



CLODA Motivation


Twitter, Facebook)

VerificationReward

Collect

Sensor / Geo Data

CLODA LOD


CLODA Prototype




CLODA: Indoor Localization• Numerous ways to localize without power-hungry GPS

but most of the solutions rely on additional hardware (RFID, sensor networks, etc.)

• Smartphones can nowadays localize off-the-shelf with onboard sensors and WiFi signal fingerprints (coined Hybrid Localization)

• These solutions require that services acquire local data through Crowdsourcing (e.g., Google Indoor)

– Building RadioMaps, MagnetometerMap, etc.– [Airplace] "The Airplace Indoor Positioning Platform for Android

Smartphones", C. Laoudias et. al., Best Demo Award at IEEE MDM'12.– [HybridCywee] "Demo: the airplace indoor positioning platform", C.-L. Li, C.

Laoudias, G. Larkou, Y.-K. Tsai, D. Zeinalipour-Yazti and C. G. Panayiotou, in ACM Mobisys'13. Video at: http://youtu.be/DyvQLSuI00I

– Wifislam.com (bought recently by Apple for 20M)



CLODA: Scanning Items

Scan & LinkLOD LOD

Preview



CLODA: Scanning Items



CLODA: Indoor Localization

Cywee / AirplaceAirplace and Anyplace

(Navigate) seamlessly indoor or outdoorhttp://anyplace.cs.ucy.ac.cy/ http://youtu.be/DyvQLSuI00I

Founded on prior work



CLODA Motivation


Twitter, Facebook)

VerificationReward

Collect

Sensor / Geo Data

CLODA LOD


CLODA Prototype




NoSQL DataStore: CouchDB

function(doc) { for (i in doc.authors) { author = doc.authors[i]; emit(doc._id, author); }}

Map Function

Results (through REST/HTTP or Futon)

Document in CouchDB



NoSQL DataStore: CouchDB

Export JSON Data to RDF with Sessel (CouchApp that

generates RDF triples from CouchDB documents)



CLODA Motivation


Twitter, Facebook)

VerificationReward

Collect

Sensor / Geo Data

CLODA LOD


CLODA Prototype


Last step essentially provided interlinking with existing LOD



CLODA on the LOD Graph!

http://www.stateofsearch.com/search-in-the-knowledge-graph-era/

CLODA



CLODA Incentives

• Incentives:– Ethical Benefit

• Similar to people-centric sensing / wardriving– Enhance collaboration between users

• Richer querying possibilities in the future.– Might be imposed by an Organization.

• E.g., Inventory Management in a Hospital



CLODA Quality Issues

• Data Quality / Data Freshness– LOD data suffers from both of these aspects– Crowdsourcing offers Freshness but still lacks

explicit Quality guarantees (repeat N times then majority vote)

• Possible Solutions: Integrate Location-aware Techniques to validate data added and linked– Task of Identifying the neighbors of all users

continuously with Proximity, see IEEE MDM'12.– Task of Identifying similarly moving users with

SmartTrace, see IEEE TKDE, June, 2013.



CLODA Testbed Issues• Currently, there are no testbeds (like motelab, planetlab)

for realistically prototyping Smartphone Network applications and protocols at a large scale.

• Currently applications are tested in emulators.– Sensors are not emulated. – Reprogramming is difficult.

• SmartLab (http://smartlab.cs.ucy.ac.cy/) is a first-of-a-kind programmable cloud of 40+ smartphones deployed at our department enabling a new line of systems-oriented research on smartphones.

"Crowdsourcing with Smartphones", Georgios Chatzimiloudis, Andreas Konstantinides, Christos Laoudias, Demetrios Zeinalipour-Yazti IEEE Internet Computing (IC '12), Special Issue: Sep/Oct 2012 - Crowdsourcing, May 2012. IEEE Press, 2012

"Demo: A Programming Cloud of Smartphones", A. Konstantinidis, C. Costa, G. Larkou and D. Zeinalipour-Yazti, "Demo at the 10th International Conference on Mobile Systems, Applications and Services" (Mobisys '12), Low Wood Bay, Lake District, UK, 2012.



CLODA Testbed Issues

SmartLab: Massive smartphone simulations with our first global open smartphone IaaS cloud –

http://smartlab.cs.ucy.ac.cy/

Static Androids[SmartLab] "Demo: a programming cloud of smartphones", A. Konstantinidis, C.

Costa, G. Larkou, D. Zeinalipour-Yazti, In ACM Mobisys '12. [ By our Group ]

Mobile Androids



CLODA Testbed Issues

http://smartlab.cs.ucy.ac.cy/


32 © Larkou, Metochi, Chatzimilioudis and Zeinalipour-Yazti, Mobisocial'13, Milan, Italy

First IEEE Intl. Workshop on Mobile Data Management, Mining and Computing on Social Networks (MobiSocial), co-located with IEEE MDM'13, June 3, 2013, Milan, Italy.

CLODA: A Crowdsourced Linked Open Data Architecture

Thanks! Questions?Georgios Larkou, Julia MetochiGeorgios Chatzimilioudis andDemetrios Zeinalipour-Yazti

http://dmsl.cs.ucy.ac.cy/

Technology

CLODA: A Crowdsourced Linked Open Data Architecture