• Title/Summary/Keyword: total reflection

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Measurement of Brownian motion of nanoparticles in suspension using a network-based PTV technique

  • Banerjee A.;Choi C. K.;Kihm K. D.;Takagi T.
    • 한국가시화정보학회:학술대회논문집
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    • 2004.12a
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    • pp.91-110
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    • 2004
  • A comprehensive three-dimensional nano-particle tracking technique in micro- and nano-scale spatial resolution using the Total Internal Reflection Fluorescence Microscope (TIRFM) is discussed. Evanescent waves from the total internal reflection of a 488nm argon-ion laser are used to measure the hindered Brownian diffusion within few hundred nanometers of a glass-water interface. 200-nm fluorescence-coated polystyrene spheres are used as tracers to achieve three-dimensional tracking within the near-wall penetration depth. A novel ratiometric imaging technique coupled with a neural network model is used to tag and track the tracer particles. This technique allows for the determination of the relative depth wise locations of the particles. This analysis, to our knowledge is the first such three-dimensional ratiometric nano-particle tracking velocimetry technique to be applied for measuring Brownian diffusion close to the wall.

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Polarized Light Out-coupling in Backlight by Collimating the Beam into Lightguide Plate

  • Hwang, Seong-Mo;Kim, Yeun-Tae;Nam, Seung-Ho;Lee, Sin-Doo
    • Journal of Information Display
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    • v.8 no.1
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    • pp.18-21
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    • 2007
  • We developed a new configuration of polarized light out-coupling lightguide plate (LGP) in the LCD backlight. By collimating the light into the LGP, one linear polarization component experienced total internal reflection at the planar interface of LGP and anisotropic layer, whereas the orthogonal polarization was out-coupled along the normal direction through a birefringent layer and subsequent isotropic microstructures.

Measurement of Refractive Index of Solid Medium by Critical Angle Method When Air Gap is Present

  • Lim, Hwan-Hong;Kwon, Moon-Soo;Choi, Hee-Joo;Kim, Byoung-Joo;Cha, Myoung-Sik
    • Journal of the Optical Society of Korea
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    • v.12 no.3
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    • pp.210-214
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    • 2008
  • A critical angle method was used to measure the index of refraction of a solid medium when an air gap between the prism and the medium is present. The gap effect was analyzed both numerically and experimentally. Since the total internal reflection is severely disturbed by the large gap, determination of the critical angle and the resulting refractive index becomes ambiguous and inaccurate. By using an index matching fluid, we could determine the index of refraction with an uncertainty of ${\pm}2{\times}1^{-3}$ even when the gap is as large as 1 ${\mu}m$.

Optical Pickup applied to Phase Shift(PS) Mirror (Phase Shift(PS) Mirror를 이용한 광 Pickup)

  • Kim, Kyeong-Min;Kim, Sang-Bae
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.337-338
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    • 2007
  • The present paper proposes the method which improves a record and remaking efficiency of the optical pickup as applying the mirror where Phase Shift(PS) principle is applied to optical pickup. Plan to get a circularly polarized light quality above quality which is embodied through Existing Quater Wave Plate(QWP) and a function of total reflection mirror as applying PS mirror which integrates QWP with the function of the total reflection to optical pickup. In the present paper, embody circularly polarized light quality through applying PS mirror to optical pickup, and it through, plan to propose to come true the optimization of recording and remaking CD/DVD disc.

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An Approach to Improve the Contrast of Multi Scale Fusion Methods

  • Hwang, Tae Hun;Kim, Jin Heon
    • Journal of Multimedia Information System
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    • v.5 no.2
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    • pp.87-90
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    • 2018
  • Various approaches have been proposed to convert low dynamic range (LDR) to high dynamic range (HDR). Of these approaches, the Multi Scale Fusion (MSF) algorithm based on Laplacian pyramid decomposition is used in many applications and demonstrates its usefulness. However, the pyramid fusion technique has no means for controlling the luminance component because the total number of pixels decreases as the pyramid rises to the upper layer. In this paper, we extract the reflection light of the image based on the Retinex theory and generate the weight map by adjusting the reflection component. This weighting map is applied to achieve an MSF-like effect during image fusion and provides an opportunity to control the brightness components. Experimental results show that the proposed method maintains the total number of pixels and exhibits similar effects to the conventional method.

Anti-Reflection Thin Film For Photoelectric Conversion Efficiency Enhanced of Dye-Sensitized Solar Cells (염료감응형 태양전지의 광전변환효율 향상을 위한 무반사 박막)

  • Jung, Haeng-Yun;Ki, Hyun-Chul;Hong, Kyung-Jin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.12
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    • pp.814-818
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    • 2016
  • DSSCs (dye-sensitized solar cells) based on $TiO_2/SiO_2$ multi layer AR (anti-reflection) coating on the outer glass FTO (fluorine-doped tin oxide) substrate are investigated. We have coated an AR layer on the surface of a DSSCs device by using an IAD (ion beam-assisted deposition) system and investigated the effects of the AR layer by measuring photovoltaic performance. Compared to the pure FTO substrate, the multi layer AR coating increased the total transmittance from 67.4 to 72.9% at 530 nm of wavelength. The main enhancement of solar conversion efficiency is attributed to the reduction of light reflection at the FTO substrate surface. This leads to the increase of Jsc and the efficiency improvement of DSSCs.

Soft Mold Imprinting Fabrication of Anti-reflection Film using Self-Organized Nanostructure Polymer Surfaces Irradiated by Ion Beams (이온빔 처리된 폴리머 표면의 자가나노구조화를 이용한 반사방지 필름 제조용 소프트 몰드 임프린팅 연구)

  • Lee, Seunghun;Byeon, Eun-Yeon;Choi, Juyeon;Jung, Sunghoon;Yu, Byeong-Gil;Kim, Do-Geun
    • Journal of the Korean institute of surface engineering
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    • v.50 no.6
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    • pp.480-485
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    • 2017
  • Soft mold imprinting method that uses nanostructured polymer mold was investigated for anti-reflection film fabrication. The nanostructured soft mold was polyethylene terephthalate(PET) irradiated by oxygen ion beams. The collisional energy transfer between oxygen ion and the polymer surface induced cross-linking and scission reactions, resulting in self-organized nanostructures with regular patterns of the wavenumber of $5{\mu}m^{-1}$. Post processes including ultra-violet curable resin coating and delamination fabricated anti-reflection films. The imprinted resin surface also showed the consistent wavenumber, $5{\mu}m^{-1}$. Pristine PET, oxygen ion beam treated PET, and imprinted replica sample showed total transmittance of 91.04, 93.25, and 93.57-93.88%, respectively.

A Study on Effects of Well-structured Cognitive Reflection Journal on Metacognition and Learning Achievement (구조화된 인지적 성찰일지가 메타인지와 학업성취에 미치는 영향에 관한 연구)

  • Park, Sun-Hee;Lee, Seung-Ki;Choi, Mi-Na
    • Journal of Engineering Education Research
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    • v.11 no.1
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    • pp.5-14
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    • 2008
  • The purpose of this study is to analyze how a well-structured cognitive reflection journal can affect a learner's metacognition and learning achievement in the area of Engineering Education. The objects of this study were 143 students in total (experimental group: 52, control group: 91) who are taking the 'Fundamental Semiconductor Engineering' course in the Engineering Department at D college in the metropolitan area. For his particular study, we undertook three steps as follows. First, we verified that the two groups of students were equal in areas of metacognition and learning achievement. Second, the experimental group was asked to keep writing the well-structured reflection journal for four weeks and the control group was not. Third, we evaluated the metacognition and learning achievement. This study used a questionnaire to measure metacognition by Sperling(2002) in a Korean translation as well as a well-structured cognitive reflection journal. As a result, we found that the well-structured cognitive reflection journal affects learners positively in the sense of metacognition ability, continuity as well as learning achievement.