Therefore, it is possible to transmit the ultrasonic wave whose directivity is different from that of {HEAD ~ the ultrasonic wave} transmitted from {TAIL ~ single transmission element} 
transmitted from
Therefore , it is possible to transmit the ultrasonic wave whose directivity is different from that of { HEAD ~ the ultrasonic wave } transmitted from { TAIL ~ single transmission element }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL