An adaptive filter is {HEAD ~ a computational device} that attempts to model {TAIL ~ the relationship} between two signals in real time in an iterative manner 
attempts to model
An adaptive filter is { HEAD ~ a computational device } that attempts to model { TAIL ~ the relationship } between two signals in real time in an iterative manner
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH