Qingdao University, Yeungnam University, Qingdao University, Qingdao University, Qingdao University, Qingdao University, affiliation not provided to SSRN, Qingdao University, Qingdao University, Qingdao University, Qingdao University, Konkuk University, Qingdao University - University-Industry Joint Center for Ocean Observation and Broadband Communication and Qingdao University