• 반도체디스플레이기술학회지
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• 제18권2호
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• pp.23-28
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• 2019

Wire breakage in drawing, which is the most critical process in glass fiber manufacturing, is caused by numerous factors such as height, drawing speed, and air flow. The vibrations of the draw tower, however, is the most dominant factor to create the wire breakage. In this study, the structure of a draw tower has been analyzed through experiments and computer simulations to figure out the main reasons of the vibrations. And the design alterations were applied to the machine to identify the effects of those alterations. The result shows that design alterations of the draw tower structure can suppress the 87% of the vibrations, and further can prevent the wire breakage.

• 공학교육연구
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• 제13권2호
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• pp.3-6
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• 2010

In this paper, we report a case study of applying puzzle solving as a programming practice. There are many students, who have attended computer programming language courses, have had difficulties in accomplishing the course assignments. It is because just following and citing the programming language course materials is not sufficient for constructing computer programs. Many professional developers have stated that computer programming for small problems is an art of puzzle solving, where developing enterprise-size computer programming projects involves architectural insights which are already dealt in software engineering literatures. Following those backgrounds, we have explored the applicability of puzzle solving in a C++ object oriented programming course and have reported the results. The experimental results show that puzzle solving is effective to the students who are interested in computer programming and have at least beginner-level knowledge and expertise, but it turned out that puzzle solving assignments still does not draw much attention of the students who are not seriously interested in computer programming.

• Journal of the Optical Society of Korea
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• 제17권4호
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• pp.300-304
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• 2013

Novel breakthrough random-hole optical fibers (RHOFs) are fabricated in a draw tower facility, by tapering an optical fiber preform packed with a silica powder mixture capable of producing air holes in situ at the high temperature of tens of hundreds in degrees Celsius. Structural and propagation characteristics of the porous RHOF are explained briefly. Experimental investigations of the invented RHOF are performed for pressure sensor applications. Remarkable results are obtained for the RHOF with desirable pressure sensitivity independent of temperature, as is required for harsh conditions as in oil reservoirs.

• Journal of the Optical Society of Korea
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• 제12권1호
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• pp.19-24
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• 2008

In this paper, we describe the fabrication process and the characteristics of polarization maintaining photonic crystal fibers (PM-PCFs). The PM-PCF is fabricated by stack-and-draw method, i.e., stacking silica capillary tubes (making a PM-PCF preform) and drawing to optical fiber. Firstly, a PM-PCF preform is formed by stacking two kinds of capillary tubes around a solid silica rod and jacketing these stacked tubes with an outer silica tube (out-jacket tube). Later, the desired preform is drawn to a fiber in a high temperature drawing tower. We also compare the polarization properties such as polarization dependent loss, birefringence, and differential group delay of the fabricated PM-PCF with those of the conventional PANDA PM fiber.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.378-389
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• 2018

본 연구는 정부 위기관리시스템에 대한 고찰을 통하여 위기관리 수준을 파악하고 문제점 및 개선방안을 도출하여 향후 효율적인 위기관리시스템 구축에 대한 시사점을 제시하는 것이다. 이를 위해 박근혜 정부의 주요 재난 사례를 통해 법 제도, 조직, 네트워크를 중심으로 위기관리시스템의 운영 실태를 살펴보았다. 연구 결과 법 제도상 법령들의 상호 연계성과, 대응 매뉴얼, 재난대비 교육 훈련이 미흡한 것으로 나타났다. 위기관리 조직은 부적절한 위기 대응, 형식적인 조직개편, 조직의 기능적 역할 부족 문제가 나타났다. 네트워크에서는 중앙-지방정부 간 관계의 문제, 부문별 협력 및 연계 미흡, 운영방식의 문제가 제기되었다. 이에 대한 개선 방안으로 포괄적 법 제도의 정비, 위기관리 조직의 대응성 확보, 유기적 네트워크 체계 구축을 제시하였다.