Funding for this research was provided by:
National Research Foundation of Korea (2017R1A2B4006407)
Article History
Received: 13 July 2017
Accepted: 11 January 2018
First Online: 18 January 2018
Ethics approval and consent to participate
: This study was approved by the Kyung Hee University Ethics Committee (KHSIRB-13-052 (EA)).
: Not applicable.
: The authors declare that they have no competing interests.
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