Funding for this research was provided by:
Ministry of Education (2016R1A6A1A03010528)
Text and Data Mining valid from 2020-02-10
Received: 18 September 2019
Revised: 13 January 2020
Accepted: 2 February 2020
First Online: 10 February 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.