1. a Department of Materials Science and Engineering/ReSEM , Chungju National University , 123 Gumdan-ri, Iryu-myeon, Chungju-si , Chungbuk , 380-702 , South Korea
2. b ZENIXON Co. LTD, Business Incubation Building , Chungju National University , 123 Gumdan-ri, Iryu-myeon, Chungju-si , Chungbuk , 380-702 , South Korea
3. c Department of Materials Science & Engineering , Chungbuk National University , 48 Gaeshin-dong, Heungduk-gu, Cheongju-si , Chungbuk , 361-763 , South Korea