• 제목/요약/키워드: multilayer structure

검색결과 478건 처리시간 0.027초

Switchable Holographic Polymer Dispersed Liquid Crystals for Full Color-Reflective Display

  • Cho, Young-Hee;Kim, Byung-Kyu;Kim, Jae-Chang
    • KIEE International Transactions on Electrophysics and Applications
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    • 제11C권3호
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    • pp.91-95
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    • 2001
  • Reflective holographic polymer dispersed liquid crystal(HPDLC) device has a multilayer structure consisting of alternate layers of polymer and liquid crystal droplets. Periodic modulation of a refractive index reflects light of a specific wavelength in accordance with Braggs law. Samples cured isotropically were illuminated with an Argon-ion lase at 514nm. We optimized the reflcetion efficiency of HPDLC as a function of monomer functionality, LC composition and irradiation intensity. The properties of the HPDLC films were observed by UV-visible spectroscopy. We found that the maximum reflection efficiency depends on the monomer functionality, LC composition, and laser intensity. We expect these films could be used in full-color reflective display by stacking them to obtain a mixture of colors.

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SOI 응용을 위한 반도체-원자 초격자 구조의 특성 (Characteristics of Semiconductor-Atomic Superlattice for SOI Applications)

  • 서용진
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권6호
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    • pp.312-315
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    • 2004
  • The monolayer of oxygen atoms sandwiched between the adjacent nanocrystalline silicon layers was formed by ultra high vacuum-chemical vapor deposition (UHV-CVD). This multilayer Si-O structure forms a new type of superlattice, semiconductor-atomic superlattice (SAS). According to the experimental results, high-resolution cross-sectional transmission electron microscopy (HRTEM) shows epitaxial system. Also, the current-voltage (Ⅰ-Ⅴ) measurement results show the stable and good insulating behavior with high breakdown voltage. It is apparent that the system may form an epitaxially grown insulating layer as possible replacement of silicon-on-insulator (SOI), a scheme investigated as future generation of high efficient and high density CMOS on SOI.

가변구조 시스템을 위한 신경회로망 학습 알고리즘 (Neural Network Learning Algorithm for Variable Structure System)

  • 조정호;이동욱;김영태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.401-403
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    • 1996
  • In this paper, a new control strategy is presented that combines sliding mode control theory with a neural network. Sliding mode control theory requires the complete knowledge of the dynamics of the controlled system. However, in practice, one often bas only a small number of state measurements. This could be a serious limitation on the practical usefulness of sliding mode control theory. A multilayer neural network is employed to solve this kind of problem. The neural network serves as a compensator without a prior knowledge about the system. The proposed control algorithm is applied to a class of uncertain nonlinear system. The robustness against parameter uncertainty, nonlinearity and external disturbances, and the effectiveness is verified by the simulation results.

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EXPRESS - CONTROL OF THIN FILM TECHNOLOGIES BY ANODIZATION SPECTROSCOPY METHOD

  • Vojtovich, D.
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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    • pp.74-76
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    • 2004
  • It is the new promising method of obtaining the information about the state of a surface of a solid body, thin and multilayer structures. An idea of the method consists in reading and analyzing the relations U(t), dU/dt(t), dU/dt(U) on an electrical cell when anodizing an investigated object. By these relation it is possible to control the presence of impurities in the metal on the path of the anodization front, a structure and characteristics of the object being oxidized as well as of an oxide which is being formed during anodizing, the change in composition of the oxide layer, the thickness and composition of metallic and dielectric layers being a part of the layers boundaries.

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기능성 LB단분자막의 물성에 관한 연구 (A Study on the Physical Properties of Functional LB Monolayers)

  • 송진원;신훈규;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.404-407
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    • 2003
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. Until now, many methodologies have been developed in order to gain a better understand. Photoisomerization in monolayers of a novel azobenzene compound, azobenzene dendrimer, was investigated for the first time by means of the absorption spectrum and Maxwell displacement current (MDC) technique. Dendrimers are well-defined macromolecules exhibiting a tree-like structure, first derived by the cascade molecule approach. According to the absorption spectrum, trans-to-cis conversion ratio was estimated to the third generation of azobenzene dendrimer deposited onto a glass substrate. Temperature-dependent induced charge with trans-cis isomerization was also measured by means of MDC technique.

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다층구조를 갖는 DWDM용 광필터의 설계 (Design of Optical Filter with Multilayer Structure filter for DWDM)

  • 정찬권;김선엽;박형근;나유찬
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2007년도 추계학술발표논문집
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    • pp.259-261
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    • 2007
  • 본 논문에서는 DWDM용 광필터를 설계하기 위하여 광섬유 다층 슬래브 도파로에 결합시킨 형태의 광섬유/다층 슬래브 결합구조의 광필터를 제안하였다. 광섬유와 슬래브의 분리간격이 $3{\mu}m$일 때 제안된 광필터는 $1.3{\mu}m$의 통신창에서 편광 독립성은 32nm로서 TM 모드와 TE 모드에 대해 중심파장이 각각 $\lambda_0=1.274755{\mu}m$$\lambda_0=1.30591{\mu}m$일 때 0.1 nm의 FWHM(Full Width at Half Maximun) 특성을 가진다.

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기판온도에 따른 PZT(4060)/(6040) 다층 박막의 유전 특성 (Dielectric Properties of PZT(4060/6040) Multilayered Thin Films with Substrate Temperature)

  • 한상욱;이상헌;이성갑;배선기;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.667-670
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    • 2004
  • The dielectric properties of PZT(4060)/(6040) multilayered thin films with substrate temperature were investigated. PZT(4060)/(6040) thin films were deposited by RF sputtering method on Pt/Ti/$SiO_2$/Si substrates with different substrate temperature of $200{\sim}700^{\circ}C$. Increasing the substrate temperature, perovskite structure was increased, and PZT (001), (110), (002), (200) peaks were increased. The relative dielectric constant and dielectric loss of PZT(4060)/(6040) multilayered thin films at the substrate temperature of $700^{\circ}C$ were 843 and 2.45, respectively at 1000(Hz).

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1-D Photonic Crystals Based on Bragg Structure for Sensing and Drug Delivery Applications

  • Koh, Youngdae
    • 통합자연과학논문집
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    • 제4권1호
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    • pp.11-14
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    • 2011
  • Free-standing multilayer distributed Bragg reflectors (DBR) porous silicon dielectric mirrors, prepared by electrochemical etching of crystalline silicon using square wave currents are treated with polymethylmethacrylate (PMMA) to produce flexible, stable composite materials in which the porous silicon matrix is covered with caffeine-impregnated PMMA. Optically encoded free-standing DBR PSi dielectric mirrors retain the optical reflectivity. Optical characteristics of free-standing DBR PSi dielectric mirrors are stable and robust for 24 hrs in a pH 12 aqueous buffer solution. The appearance of caffeine and change of DBR peak were simultaneously measured by UV-vis spectrometer and Ocean optics 2000 spectrometer, respectively.

측면 연마 광섬유가 금속 박막이 포함된 평면 도파로 사이의 광 결합 (Optical coupling between a side polished fiber and planar waveguide including a thin metal film)

  • 김광택;황중호;이준옥;김상우;강신원;서동일;손재원
    • 한국광학회지
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    • 제12권5호
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    • pp.406-413
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    • 2001
  • 측면이 코어 가까이 연마된 단일모드 광섬유 위에 금속박막이 포함된 평면 도파로가 올려진 광섬유-평면도파로의 파장 및 편광 선택성에 관하여 이론 및 실험 결과를 보고한다. 금속 박막이 포함된 평면도파로의 특성을 구하기 위한 간단하지만 정확한 해석기법을 기술하였다. 소자를 1차원으로 등가화 시켜 결합모드 이론으로 소자의 거동을 분석하였다. 금속막의 두께와 최상부층 물질의 굴절률이 동작 특성에 미치는 영향을 측정하였고 그 결과는 설명 하였다.

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AZO/Ag/AZO 다층박막의 Ag두께에 따른 특성 연구 (Influence of Ag thickness on properties of AZO/Ag/AZO Multi-layer Thin Films)

  • 연제호;김홍배
    • 반도체디스플레이기술학회지
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    • 제16권2호
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    • pp.27-31
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    • 2017
  • AZO/Ag/AZO multi-layer films deposited on glass substrate by RF magnetron sputtering and thermal evaporator have a much better electrical properties than Al-doped ZnO thin films. The multi-layer structure consisted of three layers, AZO/Ag/AZO, the electrical and optical properties of AZO/Ag/AZO were changed mainly by thickness of Ag layers. The optimum thickness of Ag layers was determined to be $90{\AA}$ for high optical transmittance and good electrical conductivity. The Ag layers thickness $90{\AA}$ is an optical transmittance greater than 80% of visible light and the obtained multilayer thin film with the low resistivity of $8.05{\times}10-3{\Omega}cm$ and the low sheet resistance $5.331{\Omega}/sq$. Applying to TCO and Solar electrode will improve efficiency.

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