• 한국컴퓨터정보학회논문지
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• 제4권3호
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• pp.60-66
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• 1999

본 논문은 새로운 교육환경에 부응하는 학습자 중심의 시뮬레이션 코스웨어를 설계 구현하였다. 그 소재는 고등학교 물리과목의 빛의 반사와 굴절로 한다. 이 논문에서는 코스웨어의 유형과 학생 중심 학습 신념이나 대체 개념을 교수-학습에 고려한 구성주의 학습 개념을 정의하고 이론적 배경을 소개한다. 컴퓨터 시뮬레이션의 교수-이론 구조 절차를 살펴보았으며. 빛의 반사와 굴절에 대한 기본적인 개념을 다루고, 구면거을의 상과 렌즈의 상을 간단한 원리와 관계식 모형으로 설명한다. 구성주의 학습이론에 근간한 컴퓨터시뮬레이션 코스웨어 설계절차를 제시하고 구현함으로써 빛의 반사와 굴절시 물체의 거리와 초점거리의 변화에 따라 상의 종류 상의 형태상의 거리가 변화함을 보여주고 있다.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.693-699
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• 2020

355nm UV pulse laser is irradiated on the surface of polyimide (PI) by LDW (Laser Direct Writing) method to produce a high sensitivity flexible humidity sensor using a simple one-step process. The LDW method continuously investigates 2-D CAD data using a galvano scanner and an F-lens. This method is non-contact, so it minimizes physical strain on the PI. Laser-induced graphene (LIG) produced by lasers has a high surface area due to its high flexibility and numerous pores and oxidizers compared to conductors. For this reason, it is highly useful as a flexible humidity sensor. The humidity sensor produced in this study was attached to the inside of a mask filter, which has become a hot topic recently, and its applicability was confirmed.The measurement of humidity measured the sensitivity, reactivity, stability and recovery behavior of the sensor by measuring changes in capacitance and resistance.

• Food Science and Biotechnology
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• 제14권3호
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• pp.344-349
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• 2005

Aldose reductase catalyzes the conversion of glucose into sorbitol. Inhibiting this enzyme in diabetes mellitus can delay or prevent pathogenic process. Aldose reductase inhibitor was screened from Korean fermented soybean pastes (Doen-jang) and purified via sequential processes of ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. Aldose reductase inhibitor was identified as genistein with molecular weight of 270 Da and molecular formula of $C_{15}H_{10}O_5$ based on UV spectrometry, $^1H$ and $^{13}C\;NMRs$, and mass spectrometry. Genistein inhibited aldose reductase of pig lens with $IC_{50}$ level of $20\;{\mu}M$. Because genistein was effective against aldose reductase of animal source, it may be a potential therapeutic agent for diabetic complications.

• 정보저장시스템학회논문집
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• 제7권1호
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• pp.19-24
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• 2011

Holographic Data Storage System, one of the next generation data storage devices, is a 2-dimensional page oriented memory system using volume holograms in writing and retrieving process. Recently photopolymer with disc type substrate was selected as a media for the Holographic Data Storage System. The disc tilt occurs when the media rotates and the external disturbance applies. The disc tilt causes the change of the angle between the reference beam and the media, the data cannot be retrieved with the right angle or other data page is retrieved. The tilt is generated in a 2-axis direction (tangential, radial). The tangential tilt direction is the same with the multiplexing plane, while the radial tilt direction is a perpendicular to the multiplexing plane. In this research we propose 2-axis tilt angle servo system. The tilt errors are measured by using external photo detector and the additional red laser. Then the tangential direction tilt is compensated by using the galvano mirror. Also the radial direction tilt is compensated by the rotating prism between the relay lens in the reference field. Finally we confirm the compensation results through the Signal to Noise Ratio(SNR) and Bit Error Rate(BER).

• World Technopolis Review
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• 제1권2호
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• pp.92-106
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• 2012

This study focuses on exploring the behaviours of high-tech start-up firms in response to the policy interventions undertaken to promote regional innovation in South Korea since 1997. High-tech start-ups and their technological entrepreneurship are increasingly considered by policy makers and academics to play a crucial role in the generation of innovation and economic development. However, this study started from a basic concern of why government intervention does not necessarily result in an increase of regional innovation capacity. To explain this concern, we constructed a new conceptual framework of 'government dependency' and apply this to 'Daedeok,' a regional innovation system in South Korea, to explore the reproduction of path dependency as an impact induced by innovation policy. This conceptual framework was developed by remodeling path dependency approaches through a systemic and interactive lens. An empirical study used qualitative interviews of start-up founders to delineate the emergence of a new development path and the extent to which dependency was reproduced in the Daedeok regional innovation system. Empirical analysis suggested that 'reliance' and 'persistence' were the crucial factors in the production and reproduction of the government dependency. Some firms accepted dependency as reliance, but others regarded it as policy utilization. Thus, a critical juncture could not be clearly identified in actors' behaviour. It was also unclear if dependency had hindered innovation, but it was shown that the regional and institutional contexts strongly influenced the reproduction process. The study concludes that the construct of government dependency can also provide useful insights into policy learning as well as the success of government interventions.

• 한국정보통신학회논문지
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• 제12권12호
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• pp.2271-2276
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• 2008

본 논문에서는 3D 영상의 해상도 개선을 위한 크기가변 확대 기법 기반의 컴퓨터적 집적 영상 재생 방법을 제안한다. 먼저 컴퓨터적 집적 영상 재생 방법에서 요소 영상 사이의 간섭 문제를 설명한다. 큰 확대개수는 요소 영상의 확대 중첩 과정에서 큰 간섭을 야기하여 재생 3D 영상의 해상도를 저하시킨다. 이 간섭 문제를 극복하기 위해서 최소 확대 계수를 계산하는 방법을 제안한다. 새로운 최소 확대 계수는 해상도가 향상된 3D 영상을 제공하며, 제안하는 방법은 기존의 방법보다 계산량이 작다. 제안하는 방법의 유용함을 보이기 위해서 컴퓨터 복원 실험을 수행하고 그 결과를 보고한다.

• 한국광학회지
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• 제14권6호
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• pp.630-635
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• 2003

광을 이용하여 암호화를 하는 경우는 위조 및 복제의 방지를 위하여 세기성분보다는 위상성분을 이용하여 주로 암호화를 하고 있다. 그러나 위상정보를 검출할 수 있는 장비가 개발된다면 정보를 유출 당할 수 있는 위험이 있다. 이러한 위험을 줄이기 위해 본 논문에서는 가상 위상영상을 이용하고 또한 정보를 다수가 공유할 수 있도록 시각 암호화(visual cryptography) 방법을 이용하여 정보를 보다 안전하게 보관하고 공유하는 시스템을 제안하였다.

• 한국광학회지
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• 제30권1호
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• pp.8-14
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• 2019

본 논문에서는 추가적인 광학부품 및 조립공정 없이 차량용 헤드램프의 cut-off line에서 발생하는 색수차를 보정하는 방법과 이를 평가하는 방법을 제안한다. 기하학적인 방법으로 색수차를 보정하기 위해 비구면 프로젝션 렌즈의 볼록면에 tilt를 적용하여 파장별 최대 출사각도의 차이를 줄였으며, 색수차를 평가하기 위한 위치와 광도를 정하고 색 좌표를 통해 색수차 기준을 제시하였다. 이러한 기하학적인 방법을 이용하여 설계된 자동차용 헤드램프를 평가한 결과 cut-off line의 색수차가 상당히 감소되었음을 확인할 수 있었다.

• 영어영문학
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• 제64권1호
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• pp.61-76
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• 2018

This essay examines Toni Morrison's African-American characters' struggle in The Bluest Eye (1970) and Home (2012) through the lens of heteronormativity, arguing that they suffer double victimization due to both their race and gender. The Bluest Eye portrays a family tragedy caused by an African-American husband and wife's failure to live up to images of gender as represented in white, middle-class media. Written forty-two years later, Home describes an African-American man and woman who establish their own lives away from gendered standards after striving to meet social expectations and becoming traumatized in the process. Their adversities stem not only from the deeply rooted racial discrimination in American society but also from subtle gendered norms implanted by heteronormativity. Morrison's characters in her earlier narrative face a tragic denouement, ultimately destroying their children's lives. By contrast, Morrison's later characters explore more utopian ways of life unfettered by heteronormativity, overcoming hardships imposed by white-centered heteronormal society. By portraying socially victimized characters, Toni Morrison problematizes the power behind the discriminatory nature of heteronormativity and suggests a more gender-neutral, egalitarian way of organizing society, free from the constraints of heterosexuality and from violence created by normalized gender rules.

• Current Optics and Photonics
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• 제6권4호
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• pp.381-391
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• 2022

Two-photon-polymerization additive-manufacturing systems feature high resolution and precision. However, there are few reports on specific methods and possible problems concerning the use of small lasers to independently build such platforms. In this paper, a femtosecond-laser two-photon-polymerization additive-manufacturing system containing an optical unit, control unit, monitoring unit, and testing unit is built using a miniature femtosecond laser, with a detailed building process and corresponding control software that is developed independently. This system has integrated functions of light-spot detection, interface searching, micro-/nanomanufacturing, and performance testing. In addition, possible problems in the processes of platform establishment, resin preparation, and actual polymerization for two-photon-polymerization additive manufacturing are explained specifically, and the causes of these problems analyzed. Moreover, the impacts of different power levels and scanning speeds on the degree of polymerization are compared, and the influence of the magnification of the object lens on the linewidth is analyzed in detail. A qualitative analysis model is established, and the concepts of the threshold broadening and focus narrowing effects are proposed, with their influences and cooperative relation discussed. Besides, a linear structure with micrometer accuracy is manufactured at the millimeter scale.