홍예선 2024-01-12T05:35:56Z 2024-01-12T05:35:56Z 1997-07-02 https://pubs.kist.re.kr/handle/201004/78755 건물유리외벽　세척용　로봇 Patent 1997-07-02 1995-04-15 117446 95-8889 KO 특허 한국과학기술연구원