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

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

The Solent 7 April Image: Image: Strait separating the Isle of Wight from English mainland Complex tidal and wave patterns Data integration on the SemSorWeb – Alasdair J G Gray

The Solent 7 April Images: Data integration on the SemSorWeb – Alasdair J G Gray

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 Image: Data integration on the SemSorWeb – Alasdair J G Gray

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

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 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

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

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

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

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 Data integration on the SemSorWeb – Alasdair J G Gray

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 Data integration on the SemSorWeb – Alasdair J G Gray

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

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 Data integration on the SemSorWeb – Alasdair J G Gray

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

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

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

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 Data integration on the SemSorWeb – Alasdair J G Gray

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

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 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

Semantic Integrator 7 April 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

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 Data integration on the SemSorWeb – Alasdair J G Gray

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

Data Translation 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray waveheightwavets

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

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

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 Data integration on the SemSorWeb – Alasdair J G Gray

D EMO 7 April 2011Data integration on the SemSorWeb – Alasdair J G Gray27

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

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

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

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

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 Data integration on the SemSorWeb – Alasdair J G Gray

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 Data integration on the SemSorWeb – Alasdair J G Gray

Acknowledgements Christian Brenninkmeijer Alvaro Fernandes Ixent Galpin Norman Paton Jean-Paul Calbimonte Oscar Corcho 7 April Data integration on the SemSorWeb – Alasdair J G Gray For more information:

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, 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, 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 Springer. (Alphabetical authorship, equal responsibility). 7 April Data integration on the SemSorWeb – Alasdair J G Gray