detect a third number of shock events in response to {HEAD ~ the shock detector} operating at {TAIL ~ the increased shock threshold}; and 
operating at
detect a third number of shock events in response to { HEAD ~ the shock detector } operating at { TAIL ~ the increased shock threshold } ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH