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