• 제목/요약/키워드: light direction

검색결과 853건 처리시간 0.028초

Analysis of Polarization Properties of Optical Isolator for Fiber Laser

  • Kim, Tae-Gon;Cheon, Min-Woo;Park, Yong-Pil;Cho, Kyung-Jae;Kang, Sung-Hak
    • Transactions on Electrical and Electronic Materials
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    • 제12권6호
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    • pp.241-244
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    • 2011
  • An isolator transmits light in the forward direction and blocks light from passing in the reverse direction. It is regarded an essential optical component in medical, industrial, and research lasers for blocking reflection beams that cause optical damage and noise. It is also used as a communicative light intensifier to expand the lifespan of devices and enhance transmission quality. This study analyzed the characteristics of the core components in the construction of a polarization-independent isolator, namely, the walk-off polarizer and the Faraday rotator. Measurement of the extinction ratio of the resultant walk-off polarizer revealed that the ratio between the vertical and horizontal rays was 1,050:1 with a laser output of 0.032 W and 1,010:1 with a laser output of 2.68 W, thus presenting ratios similar to 1,000:1. In addition, the walk-off polarizer and Faraday rotator constructed in this study were used to compare output changes according to changes in power of input light and to check the penetration ratio. Results from the study presented variations in output value according to changes in power of input light. However, the average penetration ratio remained relatively consistent (~81.4%).

Light Field 기술개발 동향 (Trends in the Technology Development of Light Field)

  • 전황수;한미경;장종현
    • 전자통신동향분석
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    • 제33권2호
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    • pp.56-63
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    • 2018
  • A light field (LF) is a field for expressing the intensity and direction of light reflected from a subject in a 3D space. Dual LF cameras are equipped in smart phones in Korea, mainly those by Samsung and LG. Lytro, Apple, Nvidia, MIT Media Lab, Magic Lip, and NHK are also developing LF camera technologies. LF displays are being researched by ETRI, Samsung Electronics, KIST, KAIST, SNU, MIT Media Lab, USC, HP, Apple, Microsoft, SeeReal, Musion Eyeliner, Dimenco, and Holografika.

광이성화 유기박막의 스위칭 특성에 관한 연구 (The Study on Swtiching Characterics of Organic Film by Photoisomerization)

  • 강용철;이우선;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.306-308
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    • 1997
  • The Maxwell displacement current was investigated in the connection with stwiching characteristics by photoisomerization of monolayers. The displacement current was generated due to the trans-to-cis photoisomerization by irradiation with ultraviolet light( λ$_1$1=360nm). whereas the displacement current was generated in the opposite direction due to the sis-to-trans photoisomerization by irradiation with visible light( λ$_1$=450nm). The reversible displacement current generation was found to be sustained by alternative irradiation with UV light and visible light.

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승용 자동차 주요 조종장치의 스테레오타입 조사 (Investigation of stereotypes for principal controls in passenger cars)

  • 기도형
    • 대한안전경영과학회지
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    • 제14권2호
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    • pp.35-40
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    • 2012
  • The aims of this study are to investigate stereotypes of motion-direction and real motion-directions for seven principal controls in passenger cars, and to compare the stereotypes and real motion-directions for the controls. The stereotypes were obtained by using questionnaire survey, in which 385 subjects participated. The real motion-direction data were gathered for 64 passenger cars including RVs and SUVs. The results showed that while there are dominant motion-directions for head light, door key and door lock controls, dominant motion-directions are not found for other controls investigated in this study. The stereotypes of motion-directions for seven controls obtained in this study were much different from those of the real data. Furthermore, the stereotypes for wiper, head light and high beam controls based on the questionnaire survey were opposite to the real motion-directions.

전극 함몰형 고효율 실리콘 태양전지에서의 texturing 효과 (Texturing Effects on High Efficiency Silicon Buried Contact Solar Cell)

  • 지일환;조영현;이수홍
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.172-176
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    • 1995
  • Schemes to trap weakly absorbed light into the cell have played an important role in improving the efficiency of both amorphous and crystlline silicon solar cells. One class of scheme relies on randomizing the direction of light within the cell by use of Lambertian(diffuse)surfaces. A second class of scheme relies on the use fo well defined geometrical features to control the direction of light wihin the cell, Widly used geometrical features in crystalline silicon solar cells are the square based pyramids and V-shaped grooves formed in (100) orientated surfaces by intersecting(III) crystallographic planes exposed by anisotropic etching. 18.5% conversion efficiency of Buried Contact Solar Cell with pyramidally textured surface has been achieved. 18.5% efficiency of silicon solar cell is one the highest record in the world The efficieny of cell without textured surface was 16.6%, When adapting textured surface to the Cell, the efficiency has been improved over 12%.

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PSD 센서를 이용한 모션캡쳐센서의 정밀도 향상을 위한 보정에 관한 연구 (A Study on the Sensor Calibration of Motion Capture System using PSD Sensor to Improve the Accuracy)

  • 최훈일;조용준;유영기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.583-585
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    • 2004
  • In this paper we will deal with a calibration method for low cost motion capture system using psd(position sensitive detection) optical sensor. To measure the incident direction of the light from LED emitted marker, the PSD is used the output current ratio on the electrode of PSD is proportional with the incident position of the light focused by lens. In order to defect the direction of the light, the current output is converted into digital voltage value by opamp circuits peak detector and AD converter with the digital value the incident position is measured. Unfortunately, due to the non-linearly problem of the circuit poor position accuracy is shown. To overcome such problems, we compensated the non-linearly by using least-square fitting method. After compensated the non-linearly in the circuit, the system showed more enhanced position accuracy.

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Dependence of Retardation Dispersion on the Ultraviolet Polarization Direction During Photopolymerization of Self-organized Smectic Reactive Mesogen Molecules

  • Jeong, Jinyoung;Choi, Yu-Jin;Jeong, Kwang-Un;Lee, Ji-Hoon
    • Current Optics and Photonics
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    • 제2권3호
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    • pp.286-290
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    • 2018
  • We investigated the dependence of the retardation dispersion on the polarization direction of ultraviolet (UV) light during the photopolymerization of self-organized smectic reactive mesogen (RM) molecules. RM retarder film that was photopolymerized with UV light linearly polarized parallel to the layer plane showed negative dispersion (ND) of retardation for a wide range of UV polymerization temperatures. On the other hand, film that was photopolymerized with unpolarized UV light showed negative dispersion in a narrow range of UV polymerization temperatures. With a certain UV polymerization temperature, the dispersion of retardation was converted from positive to negative, depending on the UV polarization.

빛을 통해 표현되는 공간인지에 관한 연구 (A Study on The Space Recognition to be represented through Light)

  • 오승남;이호중
    • 한국실내디자인학회논문집
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    • 제14권2호
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    • pp.188-196
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    • 2005
  • The light has been considered as a main character that can not be omitted in architecture since ancient time. The recognition of space by light means that light makes the fictional space recognizable concretization. Light and shade make emptiness and substance can be easily recognized. Also reiteration and location of light and shade change the degree of acknowledgement. The character of light can strengthen or weaken the power of recognition concerning territory, direction and location. Also it can broaden, close, and segregate the domain and eventually strengthen recognition. In this study, I will try to find how space can be recognized with the help of light in architectural territories in terms of actual states. Also the main aim of my study will be the study of the light application in real space with the architectural example of space recognition by light and possible opportunity of it in space plan.

종교공간에 있어서 현상학적인 빛의 연출에 관한 연구 (A Study on the Effects of the Phenomenological Light in the Religious Space)

  • 김미례;김문덕
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 추계학술발표대회 논문집
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    • pp.135-140
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    • 2006
  • From the ancient to contemporary architecture, the light has been an important theme determining the characteristics of interior space. Especially in the religious space, the light was manipulated to express the worship for a god more than a physical element of the nature. It implied that human's space perception through the light was considered prior to the space itself. The perceptual experience in space was primarily elicited by the light with other factors, such as water, texture, and sound which temporarily renewed and updated the information of space. In this study, we critically analyzed the effects of the light which enhanced human's perceptual experience in the religious space in the view of Merleau Ponty's phenomenological philosophy. We suggested that the light was one of the mos4 effective factors to express the characteristics of the religious space with respect to the Phenomenological Light which contributed to the continuity of time, expansion and direction of space, immaterialzation, and perceptual illusion.

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Structure and Function of the Phytochromes: Light Regulation of Plant Growth and Development

  • Park, Chung-Mo;Song, Pill-Soon
    • Journal of Photoscience
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    • 제10권1호
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    • pp.157-164
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    • 2003
  • Light exerts two primary roles in plant growth and development. Plants acquire all biochemical energy required for growth and propagation solely from light energy via photosynthesis. In addition, light serves as a medium through which plants recognize environmental fluctuations, such as photoperiod and presence of neighboring animals and plants. Plants therefore constantly monitor the direction, intensity, duration, and wavelength of environmental light and integrate these light signals into the intrinsic regulatory programs to achieve an optimized growth in a given light condition. Although light regulates all aspects of plant growth and developmental aspects, the molecular mechanisms and signaling cascades involved have not been well established until recently. However, recent advances in genetic tools and plant transformation techniques greatly facilitated the elucidation of molecular events in plant photomorphogenesis. This mini-review summarizes the gist of recent findings in deetiolation and suppression of shade avoidance response as classic examples of the phytochrome-mediated photomorphogenesis.

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