• Title/Summary/Keyword: Glare Index

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Evaluation of Discomfort Glare Indices in Office Lighting (사무실 조명에서의 Discomfort Glare 계산법 적용 및 평가)

  • Hur, Nam-Don;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.6
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    • pp.13-21
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    • 2002
  • In the interior lighting, usually we refer to TAL and general lighting. The last one is that we generally adopt it in the interior lighting conditions. Here, glare is most important factor of them, especially in working place using VDT. Reference or development of estimation on glare has been studied in CIE, IESNA etc. and these of glare regulations now are applied differently in the interior lighting design or estimation on glare. But we have no glare regulation in detail, of course except G classification, which has limit of itself, so in my case it is impossible to apply in the interior lighting. On this paper, with some of main glare regulations in the world and our conditions in the interior lighting which are selected carefully, in an actual state it has been estimated So, it intended to blow which one is most suitable or what factors are considered of them, also show glare index which are appropriate to our interior lighting.

Assessment of The Luminance Distribution from Daylighting window by Using Image Processing Methodology (이미지 프로세싱 기법을 활용한 채광창의 휘도분포 평가)

  • Park, Jong Myung;Lim, Hong Soo;Kim, Jeong Tai;Kim, Gon
    • KIEAE Journal
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    • v.12 no.5
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    • pp.77-84
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    • 2012
  • Daylighting is the controlled admission of natural light into a space, reducing electric lighting and saving energy. By providing a direct link to the dynamic and perpetually evolving patterns of outdoor illumination, daylighting helps create a visually stimulating and comfort environment for building occupants, while reducing energy costs. Especially, however, glare is the most important factor in daylighting, which is issued by incoming direct sunlight into windows. This study analyzed the discomfort glare on a daylighting window by using Image processing methodology and found a solution to problems with glare source of occupants. There are several ways to evaluate discomfort glare such as UGR (Unified Glare Rating) of CIE, DGI (Daylight Glare Index, Hopkinson, 1972) and VCP (Visual Comfort Probability) of IES. These are used to apply to the relatively little artificial light source and they cannot cover discomfort glare from a real daylighting window. In this regarding, this paper aimed to calculate DGI index of the real daylighting window in a experimental space by using image processing methodology. The variables and outcomes are luminance distribution of non-shading window, effect of venetian blind installed on the window and locations related to position index of DGI.

Effects of Security Lighting Lamps on Discomfort Glare to Indoor Occupants

  • Lee, Yoon Jeong;Kim, Jeong Tai
    • KIEAE Journal
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    • v.15 no.4
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    • pp.21-28
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    • 2015
  • Purpose: Although security lights are used to secure pedestrian visibility and safety at nighttime, they can generate light trespass in the neighboring residential space. To prevent this, standards for acceptance limits on vertical illuminance and light pollution by the windows of residential buildings are presented. Method: This study thus representatively selected three types of lamps and, through an evaluation and analysis of the physical and subjective discomfort glare per lamp, proposed a discomfort glare index for each lamp. The evaluation and analysis according to the lamps were conducted through experiments. The variables were the security lights' lamps (NH 100W, MH 70W, LED 50W), installation angles ($0^{\circ}$, $20^{\circ}$), and installation distances (3m, 5m, 7m, 9m). Result: According to the results of the discomfort glare evaluation depending on the angles and distances of the security lights, the following minimum standards are proposed: for NH 100W, a discomfort glare index of 30 and an installation distance of 4m; for MH 70W, a discomfort glare index of 32 and an installation distance of 4m; and, for LED 50W, a discomfort glare index of 31 and an installation distance of 6m, respectively. In addition, this paper recommends the use of MH 70W, when the road width is 4m-6m, and LED 50W, when the road width is over 6m, respectively.

A Comparative Study on Discomfort Glare Sensation in Entire Visual Field for Position Index (포지션 인덱스 작성을 위한 상·하부 시야의 불쾌글레어감 비교)

  • Kim, Won-woo;Park, Sung-Ryul;Kim, Jeong Tai
    • KIEAE Journal
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    • v.7 no.6
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    • pp.37-43
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    • 2007
  • Discomfort glare is an important factor influencing appraisal for lighting environment. Unified Glare Rating (UGR) which has been proposed by CIE is one of the formula for evaluating discomfort glare. Position index is an important factor in the UGR formula. Position index was proposed by Guth in 1949. It has been used until present limiting upper visual field. Lower visual field has different sensation of brightness in comparing with upper visual field. Therefore, it is necessary to propose position index about lower visual field. The objective of this study is to investigate the brightness sensation in upper and lower visual field. First, the visual field was measured on the self-made Glare Tester. Second, luminance of the Borderline between Comfort and Discomfort (BCD) was measured on the glare Tester. Circular sources of brightness were located at various angular distances from the line of vision along five meridians, $0^{\circ}$, $45{\circ}$, $90{\circ}$, $-45{\circ}$, $-90{\circ}$. The size of the glare source is 0.0011sr. The luminance of the surrounding field, which extended over the entire visual field, was maintained $34ccd/m^2$. Ten subjects aged from 25 to 29 were participated in the experiment. The results show that the luminance of BCD on the line of vision is $4337cd/m^2$ and the glare sensation of the lower visual field is more sensitive than the upper visual field.

Subjective Evaluation of Glare for Blinking and Colors of Vertical LED Lighting (수직형 LED 조명의 색상 및 점멸에 따른 눈부심 주관평가)

  • Jung, Hyun-Ji;Kim, In-Tae;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.1
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    • pp.22-30
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    • 2015
  • Currently, in South Korea, 'Light Pollution Prevention Act by Artificial Lighting' has been enforced. For advertising lighting, it is limited based on only the light-emitting luminance. Luminance is a concept related to the glare. Not only the luminance of the light source, but also glare is affected depending on some situations like blinking, luminance contrast, background illuminance. This study conducted glare subjective evaluation with brightness, color, and blinking by looking at the LED lighting box. The results showed that the glare indexes were higher about 2 times in a decrease of background illuminance from 100lx to 0lx. The glare index of R, G, B light was higher than that of white light. The average glare index of the blue light was higher about 8 times compared to 2,700K. And the blink rate had little effect on the glare, but it affected the irritation. Therefore, the glare effect of light color and blinking needs to be considered for the standard of luminous environment.

A Study on the Optimal Window Floor Ratio Acording to Transmitance of Dye Sensitized Solar Cell(DSSC) by Analysis of Daylighting perfomance and Glare Index of Transmitance (염료감응태양전지의 투과율에 따른 채광성능 및 현휘지수 분석을 통한 적정창면적비에 대한 연구)

  • Oh, Myung-Hwan;Sim, Se-Ra;Lee, Chul-Sung;Chin, Kyung-Il;Yoon, Jong-Ho
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.92-97
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    • 2009
  • It is more necessary to consider the various factors for developmenting visible PV module of alternative window than traditional PV module. It must have sufficient performance which is Tvis, daylighting, daylight factor, glare index. so that more needs to consider suitable plan and total evaluated technology. Under the this background. For using commonly a combination BIPV module system and Daylinghting that can alternative architectural window, our goal on this study is drawing proper window area ratio as the window by analyzing lighting performance and glare index depending on transmittance of DSSC. On this study, we drew the result about window area ratio that can apply in the building when applying DSSC in the window. In situation that window is alternated as curtain wall in atrium that has big Widow area, if applying red 15.8% DSSC of low transmittance, it is expect to proper because it is suitable illumination standard and doesn't occur a discomfort glare. In case of office, we propose to apply red 33.2% or blue 35.2% DSSC of high transmittance for no affecting lighting load. we expect to contribute to select proper and effective window when applying the window in the building by drawing the window area ratio that can apply in thee building depending on transmittance of DSSC and offering the glare index data.

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Analysis of Elderly Driver's Visual Function (고령 운전자의 시각적 기능 분석에 관한 연구)

  • Kim, Jung Bok;Hwang, Jeong Hee;Chu, Byoung Sun
    • The Korean Journal of Vision Science
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    • v.20 no.4
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    • pp.505-511
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    • 2018
  • Purpose : This study investigated the visual functions of drivers aged over 65 year olds and drivers aged 50~65 year olds. In addition, difference of visual functions between professional drivers and normal drivers were investigated. Methods : Forty Driver aged over 65 year olds and 67 drivers aged less than 67 year olds were participated. All participants had more than 5 years of driving experiences and had no ocular pathology. Demographic data(gender, job, age, body condition) and visual functions such as contrast sensitivity(CS), stereopsis, glare recovery time and discomfort glare index were measured. Results : Constrast sensivity under photopic condition was higher with bus driver group. In addition, difference of CS at 12cpd and 18cpd were signifcantly different between normal drivers(1.57) and bus drivers(1.70) (p<0.05). There was no significant difference for glare recovery time, despite of trend of longer recovery time with age. Discomfort glare index was significantly different that normal drivers with more than 65 year olds had 3, taxi and truck driver presented almost 5 index score (p<0.05). Conclusion : Analysis of visual function of elderly drivers, it was confirmed that their visual functions decreased with age. Therefore, visual function tests such as CS, discomfort glare index and stereopsis in addition to current available test may need to be considered for drivers aged over 65.

A Study on the Design of a Floodlighting Tower with LED Source of Light Considering the Reduction of a Glare (눈부심 저감을 고려한 LED광원 계류장 조명탑 설계에 관한 연구)

  • Kim, Dong-Su;Huh, Chang-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.4
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    • pp.271-275
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    • 2015
  • The floodlighting assists the pilot in taxiing the aircraft into and out of the final parking position and provide lighting suitable for passenger to embark and debark and for personnel to load and unload cargo. It is composed of sodium lamps which is consuming high energy. It needs to develop a dedicated LED lamp to replace the existing lamps. In this paper, We propose a suitable asymmetric angle of LED lamps to avoid a pilot's glare and to meet the standard illumination. For this, we analyze asymmetric angle of sodium lamps which are using in airport and confirm whether the illumination distribution and glare index meet the relating standards by using simulation method. Also, we study the needs of asymmetric characteristics of LED ramp by simulating the LED lamps with and without asymmetric characteristics of ramp respectively. With the simulation result, finally we propose the best asymmetric angle of LED lamp to meet the average illumination standard, and avoid a pilot's glare.

Development of Anti-Glare Coating Technique Using Screen Printing (스크린 프린팅 기법을 이용한 눈부심 방지 기술 개발)

  • Choi, Jeongju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.272-277
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    • 2019
  • In this paper, a manufacturing method of an anti-glare cover glass on LCD for outdoor use is proposed. The main specification of cover glass is hardness and anti-glare. Hardness is achieved by using the tempered glass, and anti-glare(AG) film is laminated to meet anti-glare specification no the tempered glass. However, the AG film is difficult to maintain the AG performance continuously because the abrasion resistance of the PET film itself is as weak as about 3H. Therefore, a novel production procedure using screen printing method is proposed. The proposed coating is implemented by applying $ZnO-B_2O_3-SiO_2$ powder on glass surface and the glass is made with enhanced hardness through tempering process. In order to apply the ZBS powder uniformly on the glass surface, a screen printing process is used. The main parameters to be considered in screen printing are the oil concentration and mesh opening size. Because the amount of ZBS powder applied to the printing process is controlled by these two parameters, the correlativity is confirmed through the experiments. In order to evaluate the performance of the proposed method, the haze, surface roughness and transmittance are selected as the performance index and are compared with the AG film. As a result of comparison, it is verified that the transmittance of the proposed tempered glass is 83.1%, which is slightly lower than 89.5% of AG film, but the hardness is more than double to 7H.

A Daylighting Design Indicator for Korean Dementia Nursing Homes Based on the Therapeutic Effects of Light - Focusing on maximizing daylight availability, optimizing therapeutic views, and minimizing glare (빛에 의한 치료적 효과 기반의 한국형 치매요양시설의 자연채광 계획지표 개발 - 주광 가용성 최대화, 치료적 조망 최적화 및 현휘 최소화 지표 중심으로)

  • Jee, Soo In
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.1
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    • pp.29-42
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    • 2023
  • Purpose: This study aimed to develop a daylighting design indicator for Korean dementia nursing homes based on the therapeutic effects of light, focusing on the serious aging index facing Korea and the importance of natural light that occupies the most important position in the therapeutic environments for the elderly with dementia. Methods: A wide range of literature-oriented research methods were mobilized to develop the daylighting design indicator of Korean dementia nursing homes. Results: The daylighting design indicator of Korean dementia nursing homes was derived from three perspectives: maximizing daylight availability, optimizing therapeutic view, and minimizing glare. In addition, eighteen basic indicators were derived within seven indicator items in the range of building layout, windows, glazing, shading devices, spaces, interior finishings, and daylight factor. Implications: The daylighting design indicator of Korean dementia nursing homes revealed in this study will contribute to realizing Korean dementia nursing homes as a therapeutic environment for the elderly with dementia.