Such signals may thus demonstrate a relationship between {TAIL ~ the pressure signal} 302 and {HEAD ~ the density signal} 304, as those signals change over time 
Such signals may thus demonstrate a relationship between { TAIL ~ the pressure signal } 302 and { HEAD ~ the density signal } 304 , as those signals change over time
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH