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나노 다공 구조를 가진 알루미나 재료의 UV 레이저 미세가공에 관한 실험적 기초 연구
신보성(Bo-Sung Shin),이정한(Jung-Han Lee) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.1
Recently UV laser is widely used to process micro parts using various materials such as polymers, metals and ceramics because it has a very high intensity at the focused spot area. It is generally known that there are still some difficulties for alumina(Al₂O₃) ceramics to directly make micro patterns like holes and lines on the surface of working material using 355nm UV laser because the alumina has a very low absorption coefficient at that wavelength. But nowadays new alumna with nano-porous holes is developed and applied to advanced micro functional parts of IT, BT and BT industries. In this paper, we are going to show the mechanism of photo-thermal ablation for nano-porous ceramics. Inside hole there is a lot of multiple reflections along the depth of hole. Experimentally we can find the micro hole drilling and micro grooving on the surface of nano-porous alumina.
신보성(Bo-sung Shin),박강수(Kang-su Park),박연경(Yeon-kyoung Bahk),고정상(Jeung-sang Go) 한국생산제조학회 2007 한국공작기계학회 춘계학술대회논문집 Vol.2007 No.-
It is well known that abrasive waterjet (AWJ) was developed a kind of high-density energy processing technologies. AWJ is used to obtain the better cutting quality of various materials such as metals, ceramics, glass and composite materials within a short manufacturing time because of the characteristics of heatless and noncontact processing. However AWJ have still been some difficulties to improve the quality of thin workpiece. In this paper, we investigate the optimal microcutting conditions of AWJ, such as maximum pressure, cutting speed and standoff distance, of thin multi-layered materials. The experimental results show that AWJ have possibilities and potential to apply to the microcutting of thin multi-layered materials for IT industrial applications.
신보성 ( Bo Sung Shin ),이석훈 ( Seok Hoon Lee ) 한국재무관리학회 2010 財務管理硏究 Vol.27 No.4
지난 1990년대 후반에서 2000년대 초반에 걸쳐 위탁 매매수수료 율 자유화, 온라인거래 활성화, 진입요건 완화에 따른 증권회사의 대규모 신규진입 등이 집중되면서 국내 증권산업은 많은 환경변화를 겪었다. 본 연구는 이러한 환경변화가 증권산업의 경쟁도에 어떠한 영향을 주었는지를 실증 분석 한다. Panzar-Rosse 모형을 통해 1990년대와 2000년대의 경쟁정도를 비교해 본 결과, 환경변화가 이루어진 2000년 이후 증권산업의 경쟁도는 비교적 큰 폭으로 상승한 것으로 나타났다. 특히 위탁매매업무에서의 경쟁도 상승폭이 매우 큰 것으로 분석되었는데, 이는 위탁 매매수수료 율 자유화와 온라인거래 활성화 등의 요인이 겹치면서 가격경쟁이 심화되었기 때문으로 보인다. 한편, 증권회사의 규모에 따른 경쟁도를 살펴본 결과, 규모가 작은 중소형 증권사들이 직면하는 경쟁도가 대형 증권사에 비해 훨씬 높은 것으로 나타났다. 이는 증권산업의 경쟁도가 전반적으로 상승하는 가운데에서도, 자본력, 인력, 점포망 등이 취약한 중소형 증권사일수록 더 많은 경쟁위험에 노출되고 있음을 보여주는 것이다. The late 1990s and the early 2000s marked the beginning of major environmental changes to Korea`s securities industry including the liberalization of the brokerage commission, the introduction of on-line trading, and an influx of startup securities firms because of regulatory changes that increased ease of entry. We investigate whether these environmental change shave impacted the degree of competition in the securities industry. Using the Panzar-Rosse method, we find that competition among securities firms has been tougher in the 2000s than in the 1990s. More specifically, the increase of competition has been greater in the brokerage business, implying that the liberalization of the brokerage commission coupled with the introduction of on-line trading has led to price competition. Our study also reveals the differing degrees of competition among large and small-and-medium size firms. Small-and-medium size securities firms are inferior to large firms in terms of size of capital, human resources, branch network, and other characteristics. Due to the differences in these characteristics, small-and-medium size firms face tougher competition than large firms.