Article History
Received: 14 December 2017
Revised: 23 June 2018
Accepted: 27 June 2018
First Online: 9 July 2018
Compliance with ethical standards
:
: The authors declare that there is no conflict of interest regarding the publication of this paper.
: All the subjects provided written informed consent prior to participation. The experimental protocol was approved by the ethics committees of Handong Global University and was conducted in accordance with the ethical standards outlined in the Declaration of Helsinki.