semantic mediation on the sensor web
DESCRIPTION
Semantic Mediation On The Sensor WebTRANSCRIPT
Semantic Mediation
On The Sensor Web
Arne Bröring, Patrick Maué, Christian Malewski,
Krzysztof Janowicz
IGARSS, 25.7.2012, München
Variety of environmental sensors…
Sensor Web
Interoperable sensor infrastructure required
Sensor Web an infrastructure which enables the interoperable usage of sensor
resources by providing services for:
(1) discovery, (2) access, (3) tasking, & (4) eventing & alerting.
Sensor Web Enablement (SWE) by
– Web Service interfaces & data encodings
Geosensor Infrastructure Stack
Application Layer
Sensor Web Layer
Sensor Layer
Challenge: On-the-fly Integration
Service 1
Service 2
Problem: Match Assurance
Observed Property:
air_flow_direction
Output:
wind_direction
Characteristics have to match syntactically & semantically!
Goal:
Automated Integration of
Sensors and Services
Sensor Bus
Application Layer
Sensor Web Layer
Sensor Layer
Sensor Bus
Semantic Mediation
Sensor Bus
Required
Characteristics
Advertised
Characteristics
Mediator *
Semantic Mediation
1. Semantic Annotation
2. Concept Creation
3. Matchmaking
4. Conversion
Semantic Annotation - Service
Via SubscribeService message:
SubscribeService * serviceA
* observedProperty
* http://sweet#Temperature
* uom
* K
* http://ssn#SurvivalRange
* <QuantityRange>
<uom code=‘m’/>
<value>-50 0</value>
</QuantityRange>
W3C SSN Ontology
Concept Creation - Service
Semantic Annotation - Sensor
...
<sml:output name = ‘water_temperature'>
<swe:Quantity
definition = 'http://sweet#WaterTemperature'>
<swe:uom code = ‘Cel' />
</sml:output>
...
<sml:capabilities>
<swe:QuantityRange
definition = ‘http://ssn#SurvivalRange’>
<swe:uom code = ‘m’ />
<swe:value>-100 0</swe:value>
</swe:QuantityRange>
Via referenced SensorML file:
Concept Creation - Sensor
Matchmaking
Conversion With SWRL Rules
Example to attach conversion rule
AdvertisedObservationValue(?aSO),
isParameterizedBy(?aSO, Celsius)
->
applyConversionRule(?aSO,
DegreeCelsiusToKelvin)
Communicating Mediation
Example of a Mediate message
Mediate * sensor1 * serviceA
* sweet#WaterTemperature
* sweet#Temperature
* <math>
<mrow>
<mi>VAL</mi>
<mo>+</mo>
<mi>273,15</mi>
</mrow>
</math>
Discussion & Future Work
Aligned ontologies are required
incorporation of automated ontology alignment
Maintenance of SWRL rules
automatic generation from unit dictionaries
Support for spatial & temporal matchmaking
Improve support for quantitative matchmaking
usage of SWRL rules
Acknowledgements
This work is financially supported by the project
Flexible and Efficient Integration of Sensors and
Sensor Web Services funded by the European
Regional Development Fund (ERDF) for NRW
(contract number N 114/2008).
Questions?
Thank you!
Arne Bröring, Ph.D.
Email: [email protected]
Project website: http://52north.org/sensorBus