1. 1 Virtualisation and Validation of Smart City Data Dr Sefki Kolozali Institute for Communication Systems Electronic Engineering Department University of Surrey Dr Payam Barnaghi Institute for Communication Systems Electronic Engineering Department University of Surrey

2. 2 Things, Data, and lots of it image courtesy: Smarter Data - I.03_C by Gwen Vanhee

3. We need more linked open data

4. (near) real-time linked open data Streams Sometimes it’s even better if we have:

5. 5 The world of IoT and Semantics

6. Semantics & the IoT − The Semantic Sensor (&Actuator) Web is an extension of the current Web/Internet in which information is given well-defined meaning, better enabling objects, devices and people to work in co-operation and to also enable autonomous interactions between devices and/or objects. 6

7. Semantic Descriptions in Semantic (Web) World 7

8. Semantic Web these days… 8

9. Semantic Sensor Web 9 “The semantic sensor Web enables interoperability and advanced analytics for situation awareness and other advanced applications from heterogeneous sensors.” (Amit Sheth et al, 2008)

10. Several ontologies and description models 10

11. 11 We have good models and description frameworks; The problem is that having good models and developing ontologies is not enough.

12. 12 Semantic descriptions are intermediary solutions, not the end product. They should be transparent to the end- user and probably to the data producer as well.

13. A WoT/IoT Framework WSN Network-enabled Devices Semantically annotate data 13 Gateway CoAP HTTP CoAP HTTP 6LowPAN Semantically annotate data http://mynet1/snodeA23/readTemp? WSN MQTT Gateway And several other protocols and solutions…

14. 14 Publishing Linked Data

15. Understanding the principles of Linked Data − It really is all about applying Tim Berners Lee's 4 rules to encourage re-use of data − use URIs as the names of things − use HTTP URIs so we can look them up − provide useful RDF when things are looked up − link to other URIs to facilitate discovery 15

16. 6 steps to publishing Linked Data − Understand the principles − Understand your data − Choose URIs for Things in your data − Setup your infrastructure − Link to other data sets − Describe and publicize your data 16

17. Key Points for Publishing Semantic annotations − We need a model (ontology) – this is often the easy part for a single application. − Interoperability between the models is a big issue. − Express-ability vs Complexity is a challenge − How and where to add the semantics − Where to publish and store them − Semantic descriptions for data, streams, devices (resources) and entities that are represented by the devices, and description of the services. 17

18. 18 Simplicity can be very useful…

19. 19 Complex models are (sometimes) good for publishing research papers…. But they are often difficult to implement and use in real world products.

20. What happens afterwards is more important − How to index and query the annotated data − How to make the publication suitable for constrained environments and/or allow them to scale − How to query them (considering the fact that here we are dealing with live data and often reducing the processing time and latency is crucial) − Linking to other sources 20

21. The IoT is a dynamic, online and rapidly changing world 21 isPartOf Annotation for the (Semantic) Web Annotation for the IoT Image sources: ABC Australia and 2dolphins.com

22. Make your model fairly simple and modular 22 SSNO model

23. 23 Semantic descriptions can be fairly static on the Web; In the IoT, the meaning of data and the annotations can change over time/space…

24. Static Semantics 24

25. Dynamic Semantics temp Celsius 12:30:23UTC 80% 51.2365 0.5703 25 But this could be a function of time and location; What would be the accuracy 5 seconds after the measurement?

26. 26 Some good existing models: SSN Ontology Ontology Link: http://www.w3.org/2005/Incubator/ssn/ssnx/ssn M. Compton et al, "The SSN Ontology of the W3C Semantic Sensor Network Incubator Group", Journal of Web Semantics, 2012.

27. Dynamic annotations for provenance data 27 S. Kolozali et al, A Knowledge-based Approach for Real-Time IoT Data Stream Annotation and Processing", iThings 2014, 2014.

28. CityPulse Ontologies: Stream Annotation Ontology

29. CityPulse Ontologies: Quality Ontology

30. CityPulse Ontologies: Complex Event Processing Ontology

31. 31 Validation of sensory linked data

32. To check RDF descriptions To enable user to validate an ontology or Linked Data Undefined classes and properties Poorly formed namespaces Problematic prefixes Literal syntax validation and other optional heuristics Validation of Sensory Linked Data

33. Related Ontologies and Terms to the SSN Ontology 6 ? ? SSN ?

34. The architecture of the SSN Validator web application Available at: http://iot.ee.surrey.ac.uk/SSNValidation/

35. A screenshot of the SSN Validation web application Available at: http://iot.ee.surrey.ac.uk/SSNValidation/

36. Tag Cloud Representation of the Related Terms Available at: http://iot.ee.surrey.ac.uk/SSNValidation/

37. SPITFIRE :SavedEnergyOf rdfs:domain :SavedEnergy :value rdf:type owl:ObjectProperty ; rdfs:domain :OV ; ssn:subPropertyOf qudt:numericValue ; rdfs:isDefinedBy. IoT.est and SemsorGridEnv @prefix ssn:. OntoSensor :event_Description a owl:FunctionalProperty, owl:DatatypeProperty ; rdfs:domain :Event ; rdfs:range xsd:string. Some examples from the validation outputs :SavedEnergyOf is NOT defined! Wrong URIs have been used! ssn:subPropertyOf is used instead of rdfs:subPropertyOf Needs to be updated: OWL-2 guidelines - FunctionalDataProperty

38. 38 Hands on Session!

39. 39 Link for the hands on session: http://iot.ee.surrey.ac.uk/citypulse/ontologies/sao/sa opy.html

40. − Thank you. − EU FP7 CityPulse Project: http://www.ict-citypulse.eu/ @ictcitypulse s.kolozali@surrey.ac.uks.kolozali@surrey.ac.uk & p.barnaghi@surrey.ac.uk p.barnaghi@surrey.ac.uk