A shock threshold of the shock detector is initialized, and a first number of shock events is detected in {HEAD ~ response} to {TAIL ~ the shock detector} operating at the initial shock threshold 
to
A shock threshold of the shock detector is initialized , and a first number of shock events is detected in { HEAD ~ response } to { TAIL ~ the shock detector } operating at the initial shock threshold
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH