Wireless Sensor and Actuator Networks for Lighting Energy ...

IF (k) small, THEN sensing rate low;
IF (k) medium, THEN sensing rate moderate;
IF (k) large, THEN sensing rate high.
The membership functions for determining the sensing rate are shown in Figure
5-7. The membership functions on the left are for fuzzification, where m is the
fuzzification parameter and max is the upper limit beyond which (k) is
deterministically considered as large. The membership functions on the right are for
defuzzification, where m SR is the defuzzification parameter, and SR min and SR max are the
minimum and maximum allowed sensing rate respectively. While m and m SR need to be
tuned, max can be specified from the nature of the sensed environment and SR min and
SR max are determined according to the specifications of the sensing tasks.
Figure 5-7 Membership functions for determining sensing rate.
The promising performance of the adaptive sensing algorithm is verified through
simulation in the next section as shown in Figure 5-9, Figure 5-10, and Figure 5-11. It
is, however, not impossible to encounter a circumstance where (k) becomes very small
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