According to the above method, depending on {HEAD ~ a combination} of {TAIL ~ transmission elements} for ultrasonic wave transmission, it is possible to change the detection area of the ultrasonic wave 
of
According to the above method , depending on { HEAD ~ a combination } of { TAIL ~ transmission elements } for ultrasonic wave transmission , it is possible to change the detection area of the ultrasonic wave
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH