• 제목/요약/키워드: Uniform lighting

검색결과 67건 처리시간 0.027초

천창루버에 의한 내부공간 바닥면 조도변화와 설치방식에 관한 연구 (A study of Illumination on Floor Surface by Flat Form Louver of Top Lighting System)

  • 김미희;태원진
    • 한국태양에너지학회 논문집
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    • 제31권6호
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    • pp.132-138
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    • 2011
  • Inducing the natural lighting into building has been commonly applied to the spaces where artistic objects are displayed to create better visual environment for the appreciation. The direct natural lighting, especially through top lighting system may, however, bring forth discoloing of highly light-sensitive materials such as paintings or demanding additional cooling load. In addition, it causes to create glare against appreciators or to yield in visual distraction due to the extreme contrast on the inner surfaces of the spaces. Shading device such as louver is capable of preventing such voidable cases with careful manipulation. This study aims to provide basic design guide-line when the flat-form louver has to be applied to top lighting system. Interaction between the daylight and louver was simulated by Reluxpro program with variation of the attachment location, the angle of the lover, surface reflectivity, to obtain the illumination of the floor surface. This study yields the louver just under the top lighting window with 90 degree angle gives the most desirable way of employment when the uniform illumination on the floor surface is required.

고 효율, 이종 전원 지원 교류 구동 발광 다이오드 조명 연구 장치 개발 (A Study on AC-Driven LED Lighting System with High Efficacy, and Heterogeneous power)

  • 임준형;김영길
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2017년도 춘계학술대회
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    • pp.555-558
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    • 2017
  • 본 논문은 서로 다른 크기의 교류 전원을 인가하더라도 균일한 소비 전력과 광 효율을 나타낼 수 있는 이종 전원 지원 AC LED 구동 장치를 설계 하였다. 서로 다른 크기의 입력 전압과 편차를 설정하여, 두 입력전압에서 전기적 광 특성이 동일함을 확인 하였다. 또한 교류 전원의 피크전압에 따라 특정 LED 구간에서 발생하는 미 점등을 개선하여, 모든 상용 교류 입력 전압에서 전 구간 LED 점등을 구현하였다.

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학습공간으로 이용되는 대학주변 커피전문점의 조명 실태 및 평가 (The Actual State and Evaluation of Artificial Lighting on Coffee Houses Using Study Place around University)

  • 최솔지;최윤정
    • KIEAE Journal
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    • 제11권6호
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    • pp.53-62
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    • 2011
  • This study aimed at suggesting improvement of lighting environment of the coffee house using study place. To this end, a series of field investigation was conducted in four possible target coffee houses around university. The field measurement included measurement of general illuminance and tabletop illuminance, observing illumination condition, and status of artificial lighting. Also, on-site questionnaire survey was administrated to 80 users of field measurement targets about using characteristics of coffee house and user's subjective response on light environment. The results are summarized as follows: (1) According to questionnaire survey, most of users checked 'learning (study and reading)' in 'purpose of coffee house using', and 'slightly dark' was checked most in each subjective response (brightness on general space and on tabletop at daytime/night); (2) as results of measurements on general illuminance and on tabletop illuminance during daytime, only one coffee house was suitable for standard; (3) as results of measurements on illuminance during night, all target coffee houses were not met the standard; (4) as results of uniformity ratios, almost uniformities of general illuminance were not met the standard except one case. The common problems of lighting environment of coffee house were analyzed as lack of daylight illumination e.g. having low amount of sunshine from skylight, un-uniformity of insolation by floor plan and absence of window blind, and un-uniformity of artificial luminous intensity e.g. lack of the number or brightness of artificial lighting, using the indirect lighting, using only local lighting, and non-uniform arrangement of artificial lighting.

Illuminance Distribution and Photosynthetic Photon Flux Density Characteristics of LED Lighting with Periodic Lattice Arrangements

  • Jeon, Hee-Jae;Ju, Kang-Sig;Joo, Jai-Hwang;Kim, Hyun-Gyun
    • Transactions on Electrical and Electronic Materials
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    • 제13권1호
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    • pp.16-18
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    • 2012
  • LED lighting systems that combine lighting capability, emotional and physiological characteristics are required for lighting source and multifunctional applications. In this work, Simulation studies using optical analysis software packages, Light Tools, are presented. This is done to estimate the uniformity ratio of illuminance and photosynthetic photon flux density (PPFD) of the periodic 2D lattice arrangements, such as square, diamond, two-way bias quadrangular, hexagonal, and Kagome lattices, under the same transmissivity, absorptance and reflectivity. It has been found out that the two-dimensional Kagome lattice arrangement exhibited high uniformity ratio of illuminance and PPFD compared to other lattices. Accordingly, these results can be used to guide a design and improve the lighting environment which in turn would maximize the uniform distributions of illuminance.

조명등기구 배선용 커넥터의 안전성 평가 및 분석에 관한 연구 (Safety Estimation and Analysis Study of the Connector for Lighting Fixture Wiring)

  • 최충석
    • 전기학회논문지P
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    • 제58권4호
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    • pp.541-545
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    • 2009
  • This study evaluated the contact resistance, insulation resistance, withstand voltage characteristics and insertion force, etc., of the wire connector used inside an integrated LITE WAY lighting fixture developed for efficient installation. Since the connector connecting the lighting fixture's internal wires is housed, it is easily connected and separated and has a structure enabling a close-fitting connection. The temperature and time applied to the high temperature characteristics test of the connector are $105^{\circ}C$ and 16 hours, respectively. The measured contact resistance of the high temperature tested connector was 3.258 mV/A, and its measured insulation resistance was greater than $10\;G{\Omega}$ All specimens demonstrated uniform insulation characteristics, which could be seen to be in good condition. From the withstand voltage test results found before and after performing the high temperature operation test on the connector for cable connection, it was confirmed that the withstand voltage characteristics between all terminals were good. The insertion force of the connector connecting the internal wiring averaged 9.67 kgf. It was observed that the insertion force between the plug housing and the female terminal, and that between the plug housing and the male terminal, were 0.680 kgf and 1.27 kgf on average, respectively.

영상처리를 이용한 용선시편의 표면결함 검사방법 (Surface Defect Inspection Method of Iron Samples using Image Processing)

  • 안현식;정규원;김정하
    • 한국정밀공학회지
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    • 제12권10호
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    • pp.78-88
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    • 1995
  • For producing iron or steel products with good quality, the concentration of the material components should be analyzed quickly with high relability using XRF(Fluorescent X-Ray Spectrometer). Since the analysis results are much dependent upon the surface con- dition, the samples have to be prepared to have good test condition. This study presents an image processing system for inspecting the surface condition of the iron test sample. In order to use thd computer vision system, we need to develop a lighting device and image processing algorithm. For the adequate lighting device of inspection system, the indirect lighting device is contrived to cut the external light and provide uniform, stable and cold light. The image processing algorithm is aimed to reduce inspection time and to get similar analyzing results to those of the experienced operators. At first, the image processing algorithm checks whether the surface of the iron sample is ground well or not. Then, the defects; hole or dig are conted and surface condition is evaluated. In addition, the algorithm gives the reliability of the analyzing results in order to help operator's decision.

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LED용 실리콘 봉지재의 경화방법이 신뢰성에 미치는 영향 (Effect of Curing Method on the Reliability of Silicone Encapsulant for Light Emitting Diode)

  • 김완호;장민석;강영래;김기현;송상빈;여인선;김재필
    • 한국전기전자재료학회논문지
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    • 제25권10호
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    • pp.844-848
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    • 2012
  • Encapsulant curing in terms of convection oven leads to thermal induced stress due to nonuniform thermal conductivity in LED package. We have adopted infrared (IR) light for silicone curing in order to release the stress. The light uniformity irradiated on an encapsulant surface is confirmed to be uniform by optical simulation. Shear strength of die paste using IR compared to convection oven is increased 19.2% at the same curing time, which indicates curing time can be shortened. The indentation depth difference between center and edge of silicone encapsulant in terms of convection oven and IR are 14.8% and 3.4%, respectively. Curing by IR also shows 2.3% better radiant flux persistency rate of LED at $85^{\circ}C$ after 1,000 h reliability test compared to convection curing.

Development of Optical Fiber-based Daylighting System with Uniform Illumination

  • Ullah, Irfan;Shin, Seoyong
    • Journal of the Optical Society of Korea
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    • 제16권3호
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    • pp.247-255
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    • 2012
  • Daylighting has a very effective role in reducing power consumption and improving indoor environments in office buildings. Previously, it was not under consideration as a major source of renewable energy due to poor reliability in the design. Optical fiber as a transmission medium in the daylighting system demands uniform distribution of light to solve cost, heat, and efficiency issues. Therefore, this study focuses on the uniform distribution of sunlight through the fiber bundle and to the interior of the building. To this end, two efficient approaches for the fiber-based daylighting system are presented. The first approach consists of a parabolic mirror, and the second approach contains a Fresnel lens. Sunlight is captured, guided, and distributed through the concentrator, optical fibers, and lenses, respectively. At the capturing stage, uniform illumination solves the heat problem, which has critical importance in making the system cost-effective by introducing plastic optical fibers. The efficiency of the system is increased by collimated light, which helps to insert maximum light into the optical fibers. Furthermore, we find that the hybrid system of combining sunlight and light emitting diode light gives better illumination levels than that of traditional lighting systems. Simulation and experimental results have shown that the efficiency of the system is better than previous fiber-based daylighting systems.

Vicarious Calibration-based Robust Spectrum Measurement for Spectral Libraries Using a Hyperspectral Imaging System

  • Chi, Junhwa
    • 대한원격탐사학회지
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    • 제34권4호
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    • pp.649-659
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    • 2018
  • The aim of this study is to develop a protocol for obtaining spectral signals that are robust to varying lighting conditions, which are often found in the Polar regions, for creating a spectral library specific to those regions. Because hyperspectral image (HSI)-derived spectra are collected on the same scale as images, they can be directly associated with image data. However, it is challenging to find precise and robust spectra that can be used for a spectral library from images taken under different lighting conditions. Hence, this study proposes a new radiometric calibration protocol that incorporates radiometric targets with a traditional vicarious calibration approach to solve issues in image-based spectrum measurements. HSIs obtained by the proposed method under different illumination levels are visually uniform and do not include any artifacts such as stripes or random noise. The extracted spectra capture spectral characteristics such as reflectance curve shapes and absorption features better than those that have not been calibrated. The results are also validated quantitatively. The calibrated spectra are shown to be very robust to varying lighting conditions and hence are suitable for a spectral library specific to the Polar regions.