Funding for this research was provided by:
Ministry of Education (2016R1D1A1A02936968)
Ministry of Health and Welfare (KR) (HI16C1501)
Ministry of Education (KR) (2014R1A5A2009242)
Text and Data Mining valid from 2019-06-24
Received: 12 March 2019
Accepted: 13 June 2019
First Online: 24 June 2019
Ethics approval and consent to participate
: This study was approved by our institutional ethics committee.
: Publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out.
: The authors declare that they have no competing interests.