Text and Data Mining valid from 2018-09-12
Received: 12 December 2017
Accepted: 3 September 2018
First Online: 12 September 2018
Ethics approval and consent to participate
: This research was approved by the Institutional Review Board of Chung-Ang University, and all participants provided written informed consent for the study.
: Not applicable.
: The authors declare that they have no competing interests.
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