Since only four parameters are needed to specify the input signal, the signal is easy to construct, and it thus practical for {TAIL ~ use} in {HEAD ~ high density disk drive applications} 
Since only four parameters are needed to specify the input signal , the signal is easy to construct , and it thus practical for { TAIL ~ use } in { HEAD ~ high density disk drive applications }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD