채경수 문성욱 2024-01-12T05:31:56Z 2024-01-12T05:31:56Z 2002-04-04 https://pubs.kist.re.kr/handle/201004/78594 광스위칭장치 Patent 2002-04-04 2000-05-04 332996 00-23922 KO 특허 한국과학기술연구원