1. Data Integration on the Semantic Sensor Web Alasdair J G Gray Information Management Group University of Manchester Seminar at Imperial College London 7 April 2011

2. Overview of the Talk Motivation: Estuarine Flooding Semantic Sensor Web – SemSorWeb –Requirements –Architecture Ontology-based query access over sensor, streaming, and stored sources Demo 7 April 20111Data integration on the SemSorWeb – Alasdair J G Gray

3. The Solent 7 April 20112 Image: http://www.chandlery-online.com/ Image: http://www.combinedops.com/ Strait separating the Isle of Wight from English mainland Complex tidal and wave patterns Data integration on the SemSorWeb – Alasdair J G Gray

4. The Solent 7 April 20113 Images: http://www.wikipedia.com/ Data integration on the SemSorWeb – Alasdair J G Gray

5. Estuarine Flood Warning Financial implications –Damage –Loss of business Personal factors –Emotional Flood prediction –Early warning/forecasting –Locations –Severity Requires correlating –Sea-state data –Weather forecasts –Details of sea defences Response Planning –Evacuation routes –Personnel deployment –… Requires more data –Traffic reports –Shipping –… 7 April 20114 Image: http://www.metro.co.uk/ Data integration on the SemSorWeb – Alasdair J G Gray

6. Flood Risk Alert: English South Coast Detect conditions likely to cause a flood “Provide details of overtopping events in the Solent region with high wind speed observations” Need to correlate data from multiple sources Sensor data Web feeds Databases and other sources Present data model in terms of the user domain: e.g. Flood risk assessment 5... Flood defences data (database) Other sources Meteorological forecasts 7 April 2011 Real-time sensor data Wave, Wind, Tide Data integration on the SemSorWeb – Alasdair J G Gray

7. 1.Accurate characterisation of conditions that define an event 2.Correlation of data of differing modalities 3.Integrating data from heterogeneous data models 4.Discovery of relevant data sources 5.Presentation and control of information 7 April 20116 Sensor Web Requirements “Provide flood risk details of overtopping events in the Solent region with high wind speed observations” Data integration on the SemSorWeb – Alasdair J G Gray

8. Ontology Network: Reconcile Terminology SSN SWEET Service Coastal Defences Ordnance Survey Additional Regions Role DOLCE UltraLite Schema FOAF Upper External SSG4Env infrastructure Flood domain 7 April 20117Data integration on the SemSorWeb – Alasdair J G Gray

9. Application Tier Middleware Tier Data Tier Application Services Semantic Registry Semantic Integrator Data Source Connectivity Bridge Applications Concrete Resource SemSorWeb Architecture 7 April 20118

10. D ATA S OURCES 7 April 20119Data integration on the SemSorWeb – Alasdair J G Gray

11. Channel Coastal Observatory: Observing Sea-State 43 sensors deployed around UK coast Measuring –Tides (7) –Waves (24) –Weather conditions (12) On and off shore Bespoke hardware Fixed functionality Fixed (low) data rate –No bursts Central data centre 7 April 201110Data integration on the SemSorWeb – Alasdair J G Gray

12. Publishing CCO Data Relational data streams –envdata_sandownpier_tide ( ts:int, Observed:float, Tz:float, Hs:float, HMax:float, Tp:float) Streaming data service Semantically annotated metadata description –Service description –Spatiotemporal data coverage –Thematic data coverage Tide height 7 April 201111Data integration on the SemSorWeb – Alasdair J G Gray

13. Environment Agency: Flood Defences Database (NFCDD) Flood defence details –Type of defence Wall Sand banks … –Location –Height –… 7 April 201112Data integration on the SemSorWeb – Alasdair J G Gray

14. Publishing NFCDD Data Relational database –locations (id:int, latitude:decimal, longitude:decimal,location:string, storm_threshold:decimal) Stored data service Semantically annotated metadata description –Service description –Spatiotemporal data coverage –Thematic data coverage Sea defences 7 April 201113Data integration on the SemSorWeb – Alasdair J G Gray

15. I NTEGRATING D ATA 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray14

16. Abstract Problem Stored data Sensor Network Integrator 7 April 201115 Sensor Network Stored data service Streaming data service Data integration on the SemSorWeb – Alasdair J G Gray

17. Data source Data stream Query capabilities Data access Types of Heterogeneity Stored data Sensor Network Integrator 7 April 201116 Sensor Network Stored data service Streaming data service Data semantics Data integration on the SemSorWeb – Alasdair J G Gray

18. Querying Approach Use ontologies as common model Requires: –Representation of RDF stream –Expressing continuous queries over an RDF stream –Establishing mappings between ontology models and data source schemas –Accessing data sources through queries over ontology model 7 April 201117Data integration on the SemSorWeb – Alasdair J G Gray

19. RDF Stream Named graph Continuously updating Triples annotated with timestamp 7 April 201118 STREAM http://www.semsorgrid4env.eu/ccometeo.srdf... (, t i ), (, t i+1 ),... cd:Observation xsd:double cd:observationResult Data integration on the SemSorWeb – Alasdair J G Gray

20. SPARQL Stream PREFIX cd: PREFIX sb: PREFIX rdf: RSTREAM SELECT ?windspeed ?windts FROM STREAM [ NOW – 1 MINUTE TO NOW STEP 5 MINUTES ] WHERE { ?WindObs a cd:Observation; cd:observationResult ?windspeed; cd:observationResultTime ?windts; cd:observedProperty ?windProperty; cd:featureOfInterest ?windFeature. ?windFeature a cd:Feature; cd:locatedInRegion cd:SolentCCO. ?windProperty a cd:WindSpeed. } 7 April 201119 cd:Observation xsd:double cd:observationResult cd:Feature cd:featureOfInterest cd:Property cd:observedProperty cd:Region cd:locatedInRegion “Every 5 minutes give me with the wind speed observations over the last minute in the Solent Region ” Data integration on the SemSorWeb – Alasdair J G Gray

21. Semantic Integrator 7 April 201120 Streaming Source Stored data Streaming Source Tuples Q SPARQL Stream query over ontology Data Translator [[Q]] SPARQL bound variables Query Translator q S 2 O Mappings SNEEql query over source schema SNEE Query Evaluation Engine [[q]] Tuples Data integration on the SemSorWeb – Alasdair J G Gray

22. Query Translation RSTREAM SELECT ?x FROM STREAM [NOW–1 MIN TO NOW STEP 5 MIN] WHERE { ?y a cd:Observation; cd:observationResult ?x. } Conjunctive queries Extended with windows Extended with window-to-stream 7 April 201121Data integration on the SemSorWeb – Alasdair J G Gray

23. Query Execution 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray22 PREFIX cd: PREFIX sb: PREFIX rdf: SELECT ?waveheight ?wavets ?lat ?lon FROM STREAM WHERE { ?WaveObs a cd:Observation; cd:observationResult ?waveheight; cd:observationResultTime ?wavets; cd:observationResultLatitude ?lat; cd:observationResultLongitude ?lon; cd:observedProperty ?waveProperty; cd:featureOfInterest ?waveFeature. ?waveFeature a cd:Feature; cd:locatedInRegion cd:SouthEastEnglandCCO. ?waveProperty a cd:WaveHeight. } Ontologies Streams v v v v envdata_rhylflats Timestamp: long Hs : float Lon: float Lat: float envdata_hornsea envdata_milford envdata_chesil envdata_westbay S 2 O Mapping Observation WaveHeigh tProperty observe dPropert y hasObservatio nResult xsd:float locatedIn Region Region Feature SPARQL Stream (SELECT Lon,timestamp,Hs,Lat FROM envdata_rhylflats) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_hornsea) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_milford) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_chesil) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_perranporth) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_westbay) UNION (SELECT Lon,timestamp,Hs,Lat FROM envdata_pevenseybay) SNEEql

24. Data Translation 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray23 4.850 1272588663 2.1230 1272587400 waveheightwavets 4.8501272588663 2.12301272587400

25. F LOOD A PPLICATION “Smashing it all together” 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray24

26. Flood Web Application Discover relevant sources –Role –Task –Location Mashup data –Layers on a map Limited execution environment –Application services provide REST access to Web services 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray25

27. Relevant Data Sources Sensor/Streaming Data Sea-state sensor data –CCO –Port authority –WaveNet Shipping –AIS Traffic Alerts –RSS feed Contextual Data Base Maps Flood defense details Land usage Weather forecasts Flooding forecasts 7 April 201126Data integration on the SemSorWeb – Alasdair J G Gray

28. D EMO http://www.semsorgrid4env.eu/services/dynamic-demo 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray27

29. Application Login 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray28

30. Initial Display 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray29

31. Sensor Data 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray30

32. Sea-state Forecast Model 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray31

33. Conclusions: SemSorWeb 1.Accurate characterisation of conditions that define an event –Declarative queries 2.Correlation of data of differing modalities –Query evaluation over streaming and stored 3.Integrating data from heterogeneous data models –Ontology-based access to streaming data 4.Discovery of relevant data sources –Semantic registry (not covered in this talk) 5.Presentation and control of information –Application service to support, e.g. smash-ups 7 April 201132Data integration on the SemSorWeb – Alasdair J G Gray

34. Conclusions Query-based access to RDF streams –SPARQL Stream Continuous query language –S 2 O mappings Relational streams to ontology Global-as-View approach –Query translation to SNEEql Query substition –Query execution by SNEE-DQP 7 April 201133Data integration on the SemSorWeb – Alasdair J G Gray

35. Acknowledgements Christian Brenninkmeijer Alvaro Fernandes Ixent Galpin Norman Paton Jean-Paul Calbimonte Oscar Corcho 7 April 201134Data integration on the SemSorWeb – Alasdair J G Gray For more information: http://www.semsorgrid4env.eu/http://www.semsorgrid4env.eu/

36. References 1.I. Galpin, C. Y. A. Brenninkmeijer, A. J. G. Gray, F. Jabeen, A. A. A. Fernandes, and N. W. Paton. SNEE: A query processor for wireless sensor networks. Distributed and Parallel Databases, 29(1-2):31–85, 2011. Special issue on Query Processing in Sensor Networks. 2.A. J. G. Gray, R. García-Castro, K. Kyzirakos, M. Karpathiotakis, J.-P. Calbimonte, K. Page, J. Sadler, A. Frazer, I. Galpin, A. A. A. Fernandes, N. W. Paton, O. Corcho, M. Koubarakis, D. De Roure, K. Martinez, and A. Gómez-Pérez. A semantically enabled service architecture for mashups over streaming and stored data. In European Semantic Web Conference (ESWC 2011), pages 300–314, 2011. To appear. 3.J.-P. Calbimonte, Ó. Corcho, and A. J. G. Gray. Enabling ontology-based access to streaming data sources. In Proceedings of 9th International Semantic Web Conference (ISWC 2010), volume 6496 of LNCS, pages 96–111, Shanghai, China, November 2010. Springer. (Alphabetical authorship, equal responsibility). 7 April 201135Data integration on the SemSorWeb – Alasdair J G Gray