• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.831-833
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• 2004

A novel transflective-type LC mode with good display performance has been developed In order to drive both transmissive and reflective modes simultaneously without any modulation of gamma in a single-gap structure, we have introduced a new design concept in the reflective region, where the capacitance is separated into liquid crystal($C_{LC}$} and organic layer($C_{OL}$), playing a key role as a voltage divider in our cap-divided VA-mode. With this cap-divided method having both merits of simplifying process and good legibility, we have achieved good optical characteristics such as high contrast ratio and wide viewing angle in a single-gap homeotropic panel design.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2003년도 하계학술대회
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• pp.286-288
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• 2003

In this paper, in order to obtain a large differential phase shift with a little change in applied voltage, a ferroelectric reflective load circuit has been designed on top of barium strontium titanate $(Ba,Sr)TiO_3$ [BST] thin film. The design of the ferroelectric reflection-type phase shifter is based on a reflection theory of terminating circuit, which has a reflection-type analogue phase shifter with two ports terminated in symmetric phase-controllable reflective networks. To achieve large amounts of phase shift in low bias-voltage range, the effects of change of capacitance and transmission line connected with two coupled ports of a 3-dB $90^{\circ}$ branch-line hybrid coupler have been investigated. A large phase shift with a small capacitance change in the parallel terminating circuit has been demonstrated in the paper.

• 정보교육학회논문지
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• 제16권3호
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• pp.363-371
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• 2012

본 연구는 프로그래밍 교육에 구성주의 교수-학습을 적용하여 프로그래밍 습득 및 전이에 미치는 영향을 분석해 보는데 목적이 있다. 이에 따라 프로그래밍 학습을 위한 구성주의 기반 교수 환경을 설계하고 이러한 환경에서 실제로 수업을 실시하였다. 본 연구의 목적 및 선행 연구에 기초하여 고안된 연구 도구를 사용하여 프로그래밍 학습 및 태도에 미치는 효과 및 관련 변인들을 측정 분석하였다. 분석 결과 구성주의 기반 프로그래밍 교수-학습 과정에서 연구 대상의 학년 및 교수 환경에 따라 유의미한 효과가 있었으며 긍정적인 영향을 미치는 것으로 나타났다. 본 연구의 결과에 대한 시사점 및 후속 연구에 대한 제언을 제시하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1070-1076
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• 2001

In this study, the room acoustics of a hall in Kimhae Performing Arts Center is discussed. The hall is designed as a multi-purpose hall. The reverberation time of the hall is varied by absorptive/reflective surfaces. A design method using both objective and subjective evaluations is investigated. As a result, the geometrical shape and the interior materials are determined.

• 한국항해학회지
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• 제19권2호
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• pp.99-106
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• 1995

A wide band design method of an electromagnetic wave absorber with square ferrite cylinders in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is also evaluated and proposed for its accuracy by comparison with Hashin-Shtrikman formulas. Based on the developed model, wide band electromagnetic wave absorbers with excellent reflective frequency characteristics in the frequency range of 30MHz to 3, 690MHz were designed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.556-559
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• 2002

We designed a low cost optical structure of transflective LCD that uses only a half number of retardation films compared to general active matrix transflective LCD. The prototype embodied by this design shows reasonable reflective and transmissive performance. This design would provide us thinner, lighter and cheaper product due to its reduced retardation film structure.

• 천문학회보
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• 제46권2호
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• pp.55.5-56
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• 2021

The optical design of the Linear-Astigmatism-Free Three-Mirror-System (LAF-TMS) for KASI-Deep Rolling Imaging Fast-optics Telescope(K-DRIFT) is presented. LAF-TMS is an all-reflective imaging system consists of three freeform mirrors. Due to its well-corrected aberrations and obstruction-free clear aperture, the LAF-TMS provides a wide field of view with very low scattered lights.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2273-2280
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• 2013

본 논문에서는 차세대 항공 감시시스템에 대하여 소개하고, 지상국 수신기 전단부 저잡음 증폭기 설계에 관하여 연구하였다. 국제 표준 문서와 기존 제품의 성능을 고려하여 수신감도, 신뢰성 등이 경쟁력 있게 전체 시스템을 링크 버짓 하였으며, 이에 적합한 저잡음 증폭기를 얻기 위해 이득, 이득 평탄도, 반사손실 등을 최적이 되도록 설계 규격을 결정하였다. 설계시 저전력, 저잡음, 고이득 특성에 적합한 바이어스 회로를 구성하였으며, 최적 설계 후 실시한 모의실험 결과로 이득은 16.24dB, 잡음지수는 0.36dB, 입출력 반사손실은 각각 -18dB와 -28dB, 주파수 안정도는 1.11을 얻었고, 제작 후 측정 결과는 이득 17dB, 잡음지수 0.51dB, 이득 평탄도 0.23dB, 입출력 반사손실은 각각 -18.28dB, -24.50dB로 전체 시스템 구성에 적합한 결과를 얻었다.

• 항공우주기술
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• 제1권1호
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• pp.177-187
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• 2002

본 논문에서는 위성탑재용 고해상도 카메라 광학부의 예비설계 내용을 소개하고 차기 위성탑재체 개발에 필요한 기술적 제안사항을 수록하였다. 위성탑재용 고해상도 전자광학카메라 개발을 위한 광학 설계로서, 685㎞ 고도에서 지상 해상도 5m 성능을 가진 카세그레인 응용 Catadioptric 설계와 Unobscured Reflective Triplet 설계를 각각 수행, 그 spot diagram 및 MTF 등을 분석하였으며 이를 제작하는데 필요한 재질과 궤도상 운용조건까지 고려하여 실제 개발에 충분한 성능을 가진 광학설계 임을 입증하였다. 또한 차세대 위성탑재용 분광영상카메라(Hyperspectral Imager) 개발을 위하여 HSI Development Model을 설계하고 제작하였는데 그 설계 내용을 본 논문에 수록하였다. Off-axis 2-mirror 체계인 Telescope 부분과 Collimator-Grating-Reimaging lens cell로 이루어진 항우연 HSI DM의 광학 설계를 소개하고, 약 25%에 이르는 MTF성능을 포함한 설계부터 성능특성까지 주요기술사항을 기록하였다.

• 설비공학논문집
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• 제27권8호
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• pp.395-401
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• 2015

Recently, many research studies have been carried out on the efficiency of light-shelf daylighting systems, especially comparing performance improvements and the limitations of reflective surfaces and their lighting performance. In this study, a crystal face reflective surface is proposed. The objective of the study is to evaluate the lighting performance of a crystal face light-shelf through a performance study. The performance study was carried out in a full scale test-bed in order to calculate the light distribution and energy consumption utilizing the standard indoor illumination as an index. The conclusions of the performance study are as follows. 1) The optimal angle of incidence for daylighting for both the operable flat type light-shelf and the crystal face light-shelf are taken in the natural environment on the dates of the winter and summer solstices, as well as the autumn and spring equinoxes. 2) The application and installation of the crystal face light-shelf can produce a 29.9%~34.3% increase of light distribution within the indoor space. However, the increase of light distribution can also lead to a decrease in the uniformity ratio, a design challenge that should be considered when applying a crystal face light-shelf. 3) It is possible to achieve a 7.98%~13.3% greater reduction in energy consumption when applying a crystal face light-shelf than when applying a flat type light-shelf. The increase in the number of crystal faces should concur with the analysis of the energy reduction. A limitation of the study is that only one predetermined pattern was performance tested for a crystal face light-shelf. In order to carry out further research on crystal face light-shelves, additional performance studies are needed based on alternative patterns and designs.