Minimum about fuzzy logic
Using in safety technique

Threshold and majority functions are often applied in solutions of fire alarm systems when fire sensors (fire detectors) with binary output are being used. Those are used in redundant number and the resulting decisions about fire risk are implemented as threshold functions. Thus, the sensors are backed up to some extent and the solution is resistant to malfunction of any sensor. Occurrence of false alarms upon abolition or disoperation of any of the sensors is also reduced.