ACKNOWLEDGMENTS
We thank our colleagues Soyeon Park, Sook-Jin Jang, Lee Bitna, and
Won-Kyung Lee for their assistance in the field. Support was provided by
the National Research Foundation (NRF) of Korea and the Korean
government, Ministry of Science, Information and Communication
Technology, and Future Planning of Korea (MSIP) (NFR-2015R1A4A1041997)
to Y-J. W.