Tsai M.S.Huang C.T.Yao S.H.2019-07-042019-07-0420069.78161E+12https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865460896&partnerID=40&md5=e84be40e8c87cbef8aa0b9d44173b3e5https://scholars.lib.ntu.edu.tw/handle/123456789/412713Dynamic analysis of contact mechanism for a piezoelectric ultrasonic motorconference paper2-s2.0-84865460896