Text and Data Mining valid from 2018-10-16
First Online: 16 October 2018
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: The authors verify that this manuscript describes a study wherein humans were subjects, the treatment of human subjects was in accordance with established ethical guidelines and appropriate institutional approval. The research that this manuscript reports was approved by the University of Seoul IRB where the first author, Yun-Jeong Shin, is affiliated.
: The authors verify that every participant for a study that this manuscript describes provided written informed consent. In prior to give informed consent, all participants were provided with detailed information of study. Written information about the study includes research purpose and procedures, potential risks and benefits of participation, confidentiality, and compensation and highlighted voluntary participation.