If the temperature is below setpoint, the output will be on longer; if the temperature is too high, the output will be off longer. The third controller type provides proportional with integral and derivative control, or PID.
Noise figure. Noise figure (NF) and noise factor (F) are measures of degradation of the signal-to-noise ratio (SNR), caused by components in a radio-frequency (RF) signal chain. It is a number by which the performance of an amplifier or a radio receiver can be specified, with lower values indicating better performance.
The difference between how much the revenue should have been, given the actual level of activity, and the actual revenue for the period. A favorable (unfavorable) revenue variance occurs because the revenue is higher (lower) than expected, given the actual level of activity for the period.