The output of the apparatus is useful for controlling {HEAD ~ process parameters} which affect {TAIL ~ image quality} 
affect
The output of the apparatus is useful for controlling { HEAD ~ process parameters } which affect { TAIL ~ image quality }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL