이명현 김대준 2024-01-12T05:36:36Z 2024-01-12T05:36:36Z 1999-11-02 https://pubs.kist.re.kr/handle/201004/78786 도재내관의　제조방법 Patent 1999-11-02 1998-02-04 5,975,905 09/018,643 US 특허 한국과학기술연구원