• 제목/요약/키워드: Aligned

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Alignment Effects for Nematic Liquid Crystal on a New Diamond-like Carbon Layer

  • Seo, Dae-Shik;Jo, Yong-Min;Hwang, Jeoung-Yeon;Lee, Sang-Keuk
    • Transactions on Electrical and Electronic Materials
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    • 제3권2호
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    • pp.1-5
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    • 2002
  • Alignment effects for nematic liquid crystal (NLC) and electro-optical (EO) characteristics of the ion beam (IB) aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the diamond-like carbon (DLC) thin film surface were studied. A high pretilt angle of 3.5$^{\circ}$ in NLC by ion beam exposure on the DLC thin film layer can be measured. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

프린지 필드에 의해 구동되는 하이브리드형 네마틱 액정 셀에서 러빙방향에 따른 전기광학 특성 (Influence of Rubbing Direction on the Electro-Optic Characteristics of Fringe Field Driven Hybrid Aligned Nematic Liquid Crystal Cell)

  • 김완철;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.957-960
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    • 2003
  • We have studied the influence of rubbing directions on electro-optic characteristics of the fringe field driven hybrid aligned nematic liquid crystal (LC) cell by computer simulation. When a LC with positive dielectric anisotropy is used, the results show that the driving voltage and transmittance decreases as the rubbing direction with respect to horizontal electric field direction increases. The reason for decrease in light transmission is the reduction of twist angle and increase of tilt angle on the center of common electrode. In this paper, we have studied how the rubbing angle effects on the transmittance of the cell by investigating a distribution of electric field and LC director.

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새로운 틸트제어법을 이용한 하이브리드 네마틱 액정 셀의 전기 광학특성 (Electro-optic Characteristics of Hybrid-aligned Nematic Cell Using Novel Tilt Angle Control Method)

  • 김강우;황정연;김종환;김영환;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.575-578
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    • 2004
  • In this study, we designed HAN(hybrid-aligned nematic) cell using novel tilt angle control method. It was possible to make novel HAN cell using a single polyimide by hot plate baking method. This new HAN cells showed slower response time as compared with conventional HAN cell. However, the alignment state and V-T curve of HAN cell using novel method were acceptable. Also, it showed better C-V characteristic than that of conventional HAN cell.

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수평 배향된 네마틱 액정 디스플레이에서 액정의 광축과 편광판축의 편향각에 따른 명암 대비비 값 비교 (Comparison of Contrast Ratio in a Homogeneously Aligned Nematic Liquid Crystal Display Depending on an Angle Between Polarizer Axis and Optic Axis of a Liquid Crystal)

  • 송일섭;원해경;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.150-152
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    • 2004
  • We have studied contrast ratio of a homogeneously aligned nematic liquid crystal (LC) display as a function of the angle between the polarizer axis and LC director. The results show that a cell configuration in which a polarizer axis facing a light source coincides with a short LC axis has a better process margin in terms of high contrast ratio than that of the cell coinciding with a long LC axis.

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$2{\times}2$ 방향성 결합형 광 변조기의 제작 연구 (Fabrication of electro-optical modulator of directional coupler $2{\times}2$)

  • 강기성;채기병;소대화
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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    • pp.113-116
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    • 1993
  • A guided - wave electro - optical modulatored directional coupler $2{\times}2$ was fabricated on X-cut $LiNbO_3$ by proton exchange wi th self-aligned method. The Electode pattern was formed by the four extra gap electrode separtion within self-aligned electrode mask. Initial cross over state turned that by controlling the anneal ing process and self-aligned electrodes are used in fabricating the electro-optical modulatored directional coupler $2{\times}2$. The modulatored directional coupler $2{\times}2$ has very good figures of merits: the measured crosstalk was -28.2 dB and the modulating valtage of 3.2[V].

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2개의 구를 지나는 유동에 대한 수치 해석적 연구 (I) -유동방향으로 놓여진 2개의 구- (Numerical Simulation of Flows Past Two Spheres (I) -Two Spheres Aligned in the Streamwise Direction-)

  • 윤동혁;양경수
    • 대한기계학회논문집B
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    • 제29권2호
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    • pp.247-254
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    • 2005
  • A parametric study on the interactions of two spheres aligned in the streamwise direction is carried out using an immersed boundary method. The numerical results for the case of single sphere for the range of $Rs{\le}300$ are in good agreement with other authors' experimental and numerical results currently available. Then, our main investigation is focused on identifying the change of the vortical structures in the presence of a nearby sphere aligned in the streamwise direction for the range $Re{\le}300$. It turns out that significant changes in physical characteristics are noticed depending on how close the two spheres are. In this paper, not only quantitative changes in the key physical parameters such as the force coefficients, but also qualitative changes in vortex structures are reported and analyzed.

Magnetic Fields of the Youngest Protostellar System L1448 IRS 2 revealed by ALMA

  • 권우진;;;;;;김종수
    • 천문학회보
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    • 제43권1호
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    • pp.44.3-45
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    • 2018
  • Magnetic fields affect star formation in a broad range of scales from parsec to hundreds au. In particular, interferometric observations and ideal magneto-hydrodynamic (MHD) simulations have reported that formation of a rotation-supported disk at the earliest young stellar objects (YSOs) is largely suppressed by magnetic fields aligned to the rotational axis of YSOs: magnetic braking. Our recent ALMA observations toward L1448 IRS 2, which has a rotation detected and its magnetic fields aligned to the rotation axis (poloidal fields) in ~500 au scales, show that the fields switch to toroidal at the center in ~100 au scales. This result suggests that magnetic braking may not be so catastrophic for early disk formation even in YSOs with magnetic fields aligned to the rotational axis.

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Vertically Aligned Carbon Film Synthesized from Magnetically Oriented Polyacetylene using Morphology Retaining Carbonization

  • Goh, Munju;Choi, Yong Mun
    • Carbon letters
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    • 제13권4호
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    • pp.226-229
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    • 2012
  • Polyacetylene (PA) films with vertically aligned fibril morphology were synthesized in homeotropic nematic liquid crystal (N-LC) solvent by using a magnetic field of 5 Tesla as an external perturbation. Scanning electron microscope (SEM) photographs indicated that the lengths of fibrils from the substrate were $5-35{\mu}m$, depending on polymerization time. Carbonization was carried out using iodine-doped PA film and a morphology-retaining carbonization method. From the SEM results, we confirmed that the vertical morphology of the PA remains unchanged even after carbonization at $800^{\circ}C$. The weight loss of the films due to carbonization at $800^{\circ}C$ is about 20% of the weight of the film before iodine doping. It is expected that vertically aligned carbon might be a precursor for preparing vertical graphite materials, which materials could be useful for electrochemical energy storage and cell electrodes.

오프셋 마스크를 이용하지 않는 새로운 자기 정합 폴리 실리콘 박막 트랜지스터 (A novel self-aligned offset gated polysilicon thin film transistor without an additional offset mask)

  • 민병혁;박철민;한민구
    • 전자공학회논문지A
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    • 제32A권5호
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    • pp.54-59
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    • 1995
  • We have proposed a novel self-aligned offset gated polysilicon TFTs device without an offset mask in order to reduce a leakage current and suppress a kink effect. The photolithographic process steps of the new TFTs device are identical to those of conventional non-offset structure TFTs and an additional mask to fabricate an offset structure is not required in our device due to the self-aligned process. The new device has demonstrated a lower leakage current and a better ON/OFF current ratio compared with the conventional non-offset device. The new TFT device also exhibits a considerable reduction of the kink effect because a very thin film TFT devices may be easily fabricated due to the elimination of contact over-etch problem.

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Skewed Angle Detection in Text Images Using Orthogonal Angle View

  • Chin, Seong-Ah;Choo, Moon-Won
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.62-65
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    • 2000
  • In this paper we propose skewed angle detection methods for images that contain text that is not aligned horizontally. In most images text areas are aligned along the horizontal axis, however there are many occasions when the text may be at a skewed angle (denoted by 0 < ${\theta}\;{\leq}\;{\pi}$). In the work described, we adapt the Hough transform, Shadow and Threshold Projection methods to detect the skewed angle of text in an input image using the orthogonal angle view property. The results of this method are a primary text skewed angle, which allows us to rotate the original input image into an image with horizontally aligned text. This utilizes document image processing prior to the recognition stage.

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