• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.609-614
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• 2014

The fringe field effects on the transient characteristics of nano-electromechanical (NEM) memory cells have been discussed by using an analytical model. The influence of fringe field becomes stronger as the size of a cell decreases. By using the proposed model, the dependency of NEM memory transient characteristics on cell parameters has been evaluated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.518-519
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• 2005

We have studied the transmittance of fringe-filed switching(FFS) using a liquid crystal with positive dielectric anisotropy. Generally, FFS having positive dielectric anisotropy has less transmittance than FFS using negative dielectric anisotropy. FFS mode transmittance depends on horizontal director deformation, however fringe filed is composed of vertical and horizontal field. Vertical field in the middle of electrode suppresses the transmittance of FFS mode, especially when we use positive one. So, it is important to prevent the LC director from the effect of vertical field. We changed the splay elastic constant and checked the transmittance. The transmittance of FFS having positive dielectric anisotropy was improved. Less tilted LC directors improve the transmittance of FFS using positive dielectric anisotropy. We can improve the transmittance by using LC which have high splay elastic constant when another LC properties are equal.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 동계학술발표회 논문집
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• pp.381-382
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• 2008

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.914-922
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• 2003

The FFS (fringe-field switching) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using a liquid crystal with negative dielectric anisotropy. We have studied cell gap-dependent electrode-optic characteristics of the FFS mode using the LC with negative dielectric anisotropy. In case of a small cell gap of 2 ${\mu}$m, the transmittance at the center of pixel and common electrodes is relatively low because effect of surface anchoring that holds the LC to the initial state is larger than that in a large cell gap of 4 .urn such that the LCs in those regions cannot rotate enough. However, in case of a large cell gap of 4 .urn, the effect of surface anchoring becomes relatively small so that the LCs at the center of pixel and common electrode can be twisted enough by applied voltage, giving rise to high transmittance. Therefore, we can conclude that the light efficiency is dependent on the cell gap.

• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.1008-1013
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• 2003

We have studied the effect of black matrix (BM) according to the dielectric anisotropy of liquid crystals (LCs) for a homogeneously aligned LC cell driven by fringe-electric field. The results show that for a LC with positive dielectric anisotropy (+LC) there is a large transmittance change when using a conductive BM, whereas the transmittance change is low for a LC with negative dielectric anisotropy (-LC). The conductive BM existing on top substrate produces vertical electric field, which makes the LC molecules be tilt upward from the substrate and have small twist angle for the +LC. However, for the -LC the conductive BM affects the LC distribution only slightly due to characteristic of the -LC orienting perpendicular to the field. Therefore, for the +LC the electro-optic characteristics are strongly dependent on conductivity of the BM on top substrate in a homogeneous liquid crystal cell driven by fringe-electric field.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.403-411
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• 2022

Appearance management is evolving as a means of self-expression or as a way of expressing one's individuality. In particular, hairstyle is the most important part of a person's appearance and accounts for 70% of the appearance. Improving people's appearance by changing their hairstyle gives them confidence. Among them, the fringe hair style plays an important role in determining the first impression and reflects the trend. Fringe is shorter and simpler than general hair treatment, but even these small treatments have the effect of changing the impression, so women are trying to transform into a fringe hair style. A previous study was conducted on four lines classified: round, heart, square, and triangular. In this study, we added them to define 5 hairlines and created them by combining each hairline. that have been produced 5 fringe hair styles that suit the shape of the face. It is expected that the results of this study will be used as educational materials for hair line and fringe hair styles in the field, contributing to the beauty industry.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.156-164
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• 2016

We demonstrated the pretilt angle effect on the viewing angle properties of a single-domain fringe-field switching (FFS) liquid crystal (LC) mode. By performing the Póincare sphere analysis, we investigated, in detail, the origin of the viewing angle asymmetry that exists in the single-domain FFS LC mode both in the field-on and field-off states. Using this analysis, we confirmed that the pretilt angle reduces the viewing angle symmetry in the single-domain FFS LC mode. Finally, we examined the effect of a zero pretilt angle on the viewing angle symmetry by evaluating real single-domain FFS LC cells.

• 한국전기전자재료학회논문지
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• 제15권8호
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• pp.720-725
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• 2002

The fringe-field switching (FFS) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using the liquid crystal (LC) with negative dielectric anisotropy. In the device, the LC director rotates almost in-plane. However, in the bright state the device shows bluish and yellowish color along parallel and perpendicular to the LC director at off-normal directions since the LC director rotates only in one direction. Such a problem was greatly improved using a wedge shape of only pixel electrodes. In this way two different field directions exist in a pixel, enabling the LC director to rotate in two opposite directions. Consequently, owing to dual domain effect when using the LC with negative dielectric anisotropy, the viewing angle characteristics are greatly improved.

• 한국진공학회지
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• 제5권4호
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• pp.278-283
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• 1996

Field terminator를 이용하여 singl path cylindrical mirror analyser를 제작하였다. 먼저 컴퓨터 모의실험을 바탕으로 CMA의 원통형 전극양단에서 fringing field effect를 최소로 하여 log-scale의 등전위면을 그대로 유지하는 terminator의 전압비와 위치 등을 구하였다. 계산된 전압을 직렬로 연결된 금속산화물저항으로 만든 voltage divider로 field terminator에 직접 인가하여 CMA의 fringing field effect를 줄이는 방법으로 개발하였다. 이 방법으로 제작된 CMA의 분해능이 $\Delta$E/E=0.4% 이상임을 확인하였다.

• 마이크로전자및패키징학회지
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• 제22권3호
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• pp.57-65
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• 2015

반도체 패키지는 여러 가지 다양한 재료로 구성되어 있으며, 제조시나 사용 환경에서 온도가 변하면 각 재료의 열팽창 계수의 차이로 인하여 굽힘변형이 발생하게 된다. 그림자 무아레 방법은 비접촉으로 전체 영역에 걸친 면외변위를 측정하는 광학적 방법이지만 측정 감도가 $50{\mu}m/fringe$ 이상이어서 반도체 패키지의 굽힘변형을 측정하기에는 적당하지 않은 면이 있었다. 본 논문에서는 그림자 무아레 시스템에 위상이동 기법을 적용하여 $12.5{\mu}m/fringe$의 향상된 감도를 갖는 측정장치를 구성하였다. 그림자 무아레 측정에서 나타나는 탈봇 현상을 고려하여 1/2 탈봇 영역에서 변형을 측정할 수 있도록 실험을 수행하였다. 위상이동에 의해 기록되는 4장의 그림자 무늬를 영상처리하여 감도가 4배 향상된 그림자 무늬를 얻어내었다. 본 논문에서 개발한 측정방법을 기존의 섬유강화 패키지 기판과 무섬유 패키지 기판에 적용하여 상온과 약 $100^{\circ}C$의 환경에서 발생하는 굽힘변형을 측정하였다.