Funding for this research was provided by:
Ministry of Science ICT and Future Planning (2016M3A9E8941329)
Text and Data Mining valid from 2019-01-19
First Online: 19 January 2019
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human or animal subjects performed by any of the authors.
: This is not needed as no studies on human subjects were performed.