A flow discouraging system includes a stator assembly, a rotor assembly, and a plurality of fingers. The impeller includes a plurality of vanes each formed into a generally rectangular plate including a tip end face that extends circumferentially to define an outer peripheral surface of the impeller, and front and rear faces respectively located on forward and rearward sides in the rotational direction of the impeller. Feature vectors may be extracted from the sampled network traffic. The outer fitting portion has an inner peripheral surface. The processing may be adaptively modified to simulate directional reception of signals by the first microphone and the second microphone when the microphones are omnidirectional. Detection of an error signal associated with the transient is used to adjust the modulation depth of the CW phase generated carrier to a null the error signal so that there is a known ratio between the coefficients of the sine and cosine terms in the interferometer output signal to allow for normalization.