Wireless Sensor and Actuator Networks for Lighting Energy ...

(a)
Figure 8-7 Sensor placement of subject No. 3.
(b)
(a)
Figure 8-8 Sensor placement of subject No. 7.
(b)
In the remaining two of the ten cases, the fused values were higher than the
meter readings. These results were not expected since it was intuitive to assume that the
lighting on the subjects’ working areas is always unblocked, and thus the sensors are
much more likely to be placed at darker spots than brighter spots. For the sensor
locations chosen by subject No. 9 as shown in Figure 8-9, the fused values were 8.38%
above the meter readings on average. Two of the sensors measured the illuminance
higher than the meter while one gave lower readings. One possible explanation of the
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