• Title/Summary/Keyword: lighting model

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Study on full color RGB LED source lighting for general lighting and Improvement of CRI (Color Rendering Index)

  • Park, Yung-Kyung
    • Science of Emotion and Sensibility
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    • v.15 no.3
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    • pp.381-388
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    • 2012
  • The purpose of this study is to check if LED lighting can be used as general lighting and examine the color rendering property of full color RGB LED lighting. CRI is one of the important properties of evaluating lighting. However the present CRI does not fully evaluate LED lightings. Firstly, the performance of a simple task was compared other than comparing CRI values for different lighting. For experimental preparation three types of lightings were used; standard D65 fluorescent tube, general household fluorescent tube, and RGB LED lighting. All three lightings show high error for Purple-Red. All three lightings show similar error for all hues and prove that color discrimination is not affected by the lighting. This proves that LED could be used as general lighting. Secondly, problems of the conventional CIE CRI method are considered and new models are suggested for the new lighting source. Each of the models was evaluated with visual experiment results obtained by the white light matching experiment. The suggested model is based on the CIE CRI method but replaces the color space model by CIELAB, color difference model by CIEDE2000, and chromatic adaptation model by CAT02.

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Dynamic Thermal Model of a Lighting System and its Thermal Influence within a Low Energy Building

  • Park, Herie;Lim, Dong-Young;Choi, Eun-Hyeok;Lee, Kwang-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.1
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    • pp.9-15
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    • 2014
  • This paper focuses on the heat gain of a lighting system, one of the most-used appliances in buildings, and its thermal effect within a low energy building. In this study, a dynamic thermal model of a lighting system is first established based on the first principle of thermodynamics. Then, thermal parameters of this model are estimated by experiments and an optimization process. Afterward, the obtained model of the system is validated by comparing simulation results to experimental one. Finally it is integrated into a low energy building model in order to quantify its thermal influence within a low energy building. As a result, heat flux of the lighting system, indoor temperature and heating energy demands of the building are obtained and compared with the results obtained by the conventional model of a lighting system. This paper helps to understand thermal dynamics of a lighting system and to further apply lighting systems for energy management of low energy buildings.

A Study on Daylight Control Method for Securing Visual Comfort and Reducing Lighting Loads on Interior Lighting Environment (실내조명환경의 시각적 쾌적성 확보 및 조명부하 저감을 위한 채광제어방법에 관한 연구)

  • Han, Sang-Pil
    • Journal of the Korean Solar Energy Society
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    • v.32 no.6
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    • pp.100-105
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    • 2012
  • In previous study, to investigate the impression of the compound lighting based on the AC-Model at the full-size room, the impressions of various compound lighting were completed as compared with that of the uniform lightings through the comparison method (a paired comparison) by Semantic Differential scaling. Also, we examined the effect of the supplementary lighting type increasing the lights at the side of the window and the blind-control lighting type, and they were compared with the existing compound lighting type. In results, pared comparison of the compound lighting and the uniform lighting, indicates that the impression of the compound lighting is generally similar to that of the uniform lighting when there are same ratios of the light from the window. Based on these results, we suggest that the AC-Model might be applied to various conditions. And we also introduce the method for daylighting that it is possible to reduce discomfort glare and to improve visual impressions as the supplementary type and blind-control type on the compound lighting. And it was found that electric power consumption of the compound lighting room was lower than that of the uniform lighting room when as same lighting ratio of the compound lighting and the uniform lighting from the window was provided or there was the lighting distribution simulated to same light ratio from the window. Since the method of the ACModel was described in the experimental condition, additional studies should be performed to determine if this model could be applied to different window configurations, lighting layout and types of a room.

Verification of Significancebetween Experiment Devices and Scaled-down Model for the Study of PSALI (PSALI 연구를 위한 실물대 실험 장치와 축소 모형간의 유의성 검증)

  • Lee, Jin-Sook;Kim, So-Yeon;Ha, Tae-Hyun;Jung, Young-Gyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.12
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    • pp.11-20
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    • 2011
  • PSALI is referred to the supplementary lighting for the interior lighting under the daily lighting situation, and pursuant to the pertinent regulations in energy savings design standard and others in recent architecture works, the importance thereof has been increasing gradually coupled with the energy performance index (EPI), energy savings plan and the like as well as expansion of submittal and implementation policies. However, this type of PSALI studies indeed have a number of limitations since it has surrounding environmental conditions in direction, season, region, climate, time, opening rate, window area ratio, actual index, reflection rate of finishing materials and others in the architecture work as well as frequent changes in interior lighting environment for variables in daily light volume flowing into the interior, and others. Therefore, this study has analyzed existing advance research cases to produce the actual-sized model and scaled-down model, and installed the artificial lighting of LED light source possible to reproduce with same capability on both models. As a result of comparison and analysis of the artificial lighting with the key light, it has certain level of error rate from the scaled down lighting device in certain rate and actual model butit was noticeably significant within specific scope.

A New Lighting System for the Inspection of Check Defect of CRT Panel (CRT 판넬의 첵 불량 검출을 위한 새로운 조명 시스템)

  • 차준혁;권인소;하종은
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.6
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    • pp.487-493
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    • 2004
  • In this Paper, we propose a lighting system for the stable detection of check defects of the CRT panel through the analysis of the lighting interaction between the lighting unit and the CRT panel. The check defect is very difficult to detect reliably because of its high sensitivity according to the direction of incident light. At first, we model the physical shape of check defects using SEM image. And then we apply physics based illumination model to investigate the optical characteristics of the check defect. Finally, we propose a lighting system for the stable detection of check defect. Experimental results show the feasibility of the proposed lighting system for check inspection.

Evaluation of Lighting Environment of Residential Space for Senior People by each Life Behavior with Mock-up Model (실물대 모형을 이용한 고령자 주거공간의 생활행위별 조명환경 평가에 관한 연구)

  • Kim, Byoung Soo;Yim, Oh Yon
    • KIEAE Journal
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    • v.7 no.5
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    • pp.35-40
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    • 2007
  • The purpose of this study is to execute evaluation experiment to know the evaluation property of lighting environment of residential space for senior people, considering visual characteristics along aging, and finally provide basic data for the lighting plan to ensure the visual amenity. Processes of this study are as follows;1) Analyzed the variation property of visual sensibility and visual ability of senior people along aging. 2) Selected 3 types of life behavior(rest, conversation and reading) after checking life behavior in residential space for senior people based on advanced study. 3) Made the Mock-up Model that Dimming is possible, actual furnace to model. 4) Executed sensitivity evaluation experiment about lighting environment. 5) Analyzed evaluation property of lighting environment of residential space for senior people. Results of this study are as follows, 1) With lens-filter, we got comfort and amenity in bulb-color lamp which has similar color temperature with red of lens filter. 2) Lighting environment tests during conversation : With lens filters, they felt comfort on bulb color in case of higher illuminance than 850lux and daylight color in 500lux. 3) Lighting environment tests at reading : With lens filter, bulb color got better score in brightness and appropriateness than daylight color.

ACHIEVING CONSISTENCY IN LIGHTING SCHEMES FOR CONSTRUCTION WORK ZONES THROUGH LIGHTING SIMULATION

  • Khaled Nassar;Soo-Young Kim
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.269-278
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    • 2007
  • Nighttime construction is being adopted by many state DOT's as a way to mitigate the impact of construction operations on the traveling public. Although a number of states have developed standard specifications for nighttime lighting, these standards are usually in the form of generic requirement statements that only specify minimum illuminance levels. The lighting standards do not include specific ways to achieve this illuminance level such as lighting arrangements and configurations for various work zone plans and construction operations. This leaves confusion between the traffic engineers and the contractors and does not guarantee consistency in those plans, thus affecting productivity and safety (lighting conditions account for 18% to 28% of work zone accidents). The main objective of this study is to utilize three dimensional animation and lighting analysis software to study and model lighting conditions of a construction site. This is expected to increase the safety and productivity of construction operations by achieving consistency in work zone lighting schemes. A computerized model was developed, called Nitelite. Various lighting schemes can be studied using the software to provide for typical applications including lighting fixture's locations, luminance, mounting height, tilt angle, and fixture type. The results from the developed software tool were validated through comparisons with previous research conducted using field measurements.

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A Reconfigurable Lighting Engine for Mobile GPU Shaders

  • Ahn, Jonghun;Choi, Seongrim;Nam, Byeong-Gyu
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.1
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    • pp.145-149
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    • 2015
  • A reconfigurable lighting engine for widely used lighting models is proposed for low-power GPU shaders. Conventionally, lighting operations that involve many complex arithmetic operations were calculated by the shader programs on the GPU, which led to a significant energy overhead. In this letter, we propose a lighting engine to improve the energy-efficiency by supporting the widely used advanced lighting models in hardware. It supports the Blinn-Phong, Oren-Nayar, and Cook-Torrance models, by exploiting the logarithmic arithmetic and optimizing the trigonometric function evaluations for the energy-efficiency. Experimental results demonstrate 12.7%, 42.5%, and 35.5% reductions in terms of power-delay product from the shader program implementations for each lighting model. Moreover, our work shows 10.1% higher energy-efficiency for the Blinn-Phong model compared to the prior art.

The Study of domestic application for the Guideline of Model Outdoor Lighting Ordinance (MLO 옥외조명 설치지침의 국내 적용성 연구)

  • Jung, Jong-Hwan;Lee, Kyumok;Gu, Jinhoi
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.11
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    • pp.20-29
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    • 2012
  • The outdoor lighting is provided for a variety of purposes, for work or recreation, for safety or security, for amenity and for advertising or display. But the effects of lighting on the natural environment can be difficult to quantify. At present, in many countries, various policies to manage the light trespass from outdoor light have been planned. For example, Model Lighting Ordinance(MLO) will allow communities to drastically reduce light pollution and glare and lower excessive light levels. The recommended practices of the IES can be met using readily available, reasonably priced lighting equipment. So, it this paper, we analyze the effect of road lighting on light trespass using by RELUX program. And then we consider the possibility of practical application of BUG rating in Korea.

A Study on The Development of The Relationship Model of Building Facades and Exterior Lighting for Streetscape Design (가로경관 조명설계를 위한 건축물 외관유형과 경관조명방식과의 상관관계모델 개발에 관한 연구)

  • 김미연;최진원
    • Korean Institute of Interior Design Journal
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    • no.40
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    • pp.139-148
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    • 2003
  • For lighting design in such diverse structures, we need lots of considerations, such as use and characteristics of the structure, harmony with its surroundings, and the function and type of lighting to be installed. The structural characteristics is determined by its shape and several vertical and horizontal factors based on the shape, which can be focused on at day time by shading, the surface structure, the quality of the surface and the color. On the other hand, they can be at night hidden in the darkness or enforced strongly by the effect of the lighting. In this paper, correlation between the ways of lighting and building facade types according to vocabularies for sensitivity is explored based upon an analysis of building facades for small-scale commerce which plays an important role in cityscape lighting design. It is considered that categorization of types of building facades, presented in this article, and the classification system of exterior lighting methods can be useful in planning lighting. And the process of the study is thought to be able to present a method about the exterior lighting planning. Furthermore, computer simulation on the bases of the correlation model of the lighting methods related to vocabularies for sensitivity about the building facade types is expected to be data and means which can be a great help for designers to predict various results quickly.