Korea University Research and Business Foundation; Kim, Hwan-Kyu; Song, Bok-Joo; Seo, Kang-Deuk; Kang, Min-Soo; Ju, Myung-Jong; Song, Hae-Min; Choi In-Taek; Kim, Sang-Gyun; Song, Sang-Hyun Patent: EP2711359 A1, 2014 ;