]> An example description of a hypothetical accelerometer sensor related to one of the SmartProducts use cases (cooking guidance). The ontology describes measurement capabilities of a class of accelerometer sensors (WiTilt v3.0 [1]), and an example of such a sensor attached to a kitchen utensil (knife). [1] http://www.sparkfun.com/datasheets/Accelerometers/WiTilt-v3.pdf Acceleration measurement capability This class describes measurement capabilities for accelerometer sensors. The property ssn:forProperty is restricted to ucum:acceleration. Acceleration observation A class describing acceleration observations. Properties ssn:observationResult, ssn:observedBy, and ssn:observedProperty are restricted accordingly. Acceleration sensor output A class describing sensor output for acceleration measurements. Properties ssn:hasValue and ssn:isProducedBy are restricted accordingly. Acceleration value Acceleration value measured in g - standard acceleration of free fall. Accelerometer is a subclass of sensing devices which measures acceleration. The individual describing a phisical quality "acceleration" is defined in the imported MobileWeb ontology of measurement units. To align the MobileWeb ontology with the SSN ontology, the class muo:PhysicalQuality from the MobileWeb ontology is defined as a subclass of the class ssn:Property. Frequency value Frequency value measured in Hz. Quantity observation value 1 1 Because SSN ontology does not specify the format of ssn:ObservationValue, in this example we define our own class representing quantities. It is characterised by the value () and the measurement unit. WiTilt 3.0 acceleration measurement capability 1 1 This class describes measurement capabilities of WiTilt 3.0 acceleration sensors. Measurement capabilities are characterised by two parameters: measurement range and frequency. Possible values of these parameters are described by classes WiTilt30MeasurementRange and WiTilt30MeasurementFrequency respectively. A specific instance of a WiTilt 3.0 sensor must have exactly one value for each of these parameters. This class describes WiTilt v3.0 accelerometers. All possible configurations of their measurement capabilities are defined using the class WiTilt30AccelerationMeasurementCapability, so the property ssn:hasMeasurementCapability is restricted to instances of this class. WiTilt 3.0 measurement frequency This class describes maximal output frequency values of WiTilt 3.0 accelerometers in four modes: degree mode (50Hz), gravity mode (135Hz), raw ADC mode (220Hz), and binary mode (610Hz). Because the SSN ontology does not specify how the values of measurement properties should be expressed, three properties are introduced: hasMeasurementPropertyValue (for exact values), hasMeasurementPropertyMaxValue (for maximal values), and hasMeasurementPropertyMinValue (for minimal values). WiTilt 3.0 measurement range This class defines possible measurement ranges of a WiTilt 3.0 accelerometer sensor. These sensors can be calibrated to measure acceleration in the ranges of +/-1.5g, +/-2g, +/-4g and +/-6g. These four ranges are expressed using instances of this class: WiTilt30MeasurementRange_1...WiTilt30MeasurementRange_4. Because the SSN ontology does not specify how the values of measurement properties should be expressed, three properties are introduced: hasMeasurementPropertyValue (for exact values), hasMeasurementPropertyMaxValue (for maximal values), and hasMeasurementPropertyMinValue (for minimal values). A specific instance of a WiTilt 3.0 accelerometer attached to a knife. Measurement capabilities of our example sensor. It is set to the "binary" mode where the frequency is 610 Hz and measures acceleration in the range of +/- 1.5g. An example of the acceleration observation produced by our ExampleWiTilt30Accelerometer. An example of the acceleration sensor output produced by our ExampleWiTilt30Accelerometer. An example knife with an attached WiTilt 3.0 accelerometer. It belongs to both ssn:Platform and ssn:Feature because it is both the platform of the sensor and the feature being observed by the sensor. 610 50 135 1.5 -1.5 2 -2 4 -4 6 -6 220 0.98