• Title/Summary/Keyword: Glare

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Study on Sensitivity of Variables of the Experiment to Evaluate Discomfort Glare of Interior Artificial Illumination (건축실내 인공조명의 불쾌글레어 평가실험에 적용된 실험변수의 민감도 분석에 관한 연구)

  • Lee, Jin-Sook;Kim, Won-Do;Kim, Chang-Soon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.1
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    • pp.24-32
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    • 2008
  • The ultimate purpose of the study is to develop a discomfort glare forecasting formula that can be practically used in Korea in order to effectively forecast discomfort glare considering the optical characteristics of the Koreans. The study was to examine the relations between discomfort glare and the variables such as luminance, background luminance, solid angle, luminous area and louver. To this end, experiments were conducted in a mock-up office that emulates the lighting environment of an ordinary office. The study was conducted by four steps as follow. First, previous studies on discomfort glare rating to define and rate discomfort glare were analyzed and modified to be applied to the experiments of this study. Second, experiment variables, variable scope, evaluation objects and evaluation points were determined after review on existing discomfort glare evaluation experimental formulas. Third, experiments were conducted in a mock-up office to be able to control variables. Finally, sensitivity of experiment variables were analyzed through examination of the relation between discomfort glare and the variables such as luminance, solid angle, louver, luminous area and subject's position. The result showed that the most influential variables on discomfort glare of an artificial light source is luminance and louver, luminous area and subject's position(solid angle) followed.

Research of the Performance Improvement of a Light Shelf Depending on the Diffusion Film Installation Position (확산필름 부착 위치에 따른 광선반 성능개선 연구)

  • Park, Eunsu;Lee, Heangwoo;Song, Seonkjae;Kim, Yongseong
    • KIEAE Journal
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    • v.17 no.3
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    • pp.91-97
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    • 2017
  • Purpose: Various studies on a light shelf are in progress, but it has the problem of glare occurrence. The present study suggested a diffusion film as the method for resolving the glare problem, and aimed to establish light shelf-related basic data by conducting the performance evaluation of a light shelf depending on the installation position of the diffusion film. Method: To carry out the light shelf performance evaluation depending on the diffusion film installation position, three cases were established: no diffusion film installation (Case 1), diffusion film installation on the reflector (Case 2), and diffusion film installation on the upper glass surface of the window for light shelf installation (Case 3); and the energy reduction performance, luminance, and luminance contrast were analyzed based on a testbed. Result: The conclusions of this study are as follows. 1) When the diffusion film was applied, the amount of light introduced through the light shelf decreased, and the average indoor illumination decreased accordingly. 2) For Case 3, the lighting energy reduction performance was identical to the lighting energy reduction efficiency of the existing light shelf; and for Case 2, it was found to be inappropriate as the lighting energy consumption increased compared to that of the existing light shelf. 3) The analysis of the glare for the cases established in this study showed that the luminance contrast was low for Case 3, and thus the glare problem could be minimized. 4) The specific angle of the light shelf could induce the glare problem by increasing the luminance depending on the external condition. 5) Based on the aforementioned contents, the installation position of the diffusion film for improving the lighting performance and glare problem of the light shelf was found to be the upper glass surface of the window for light shelf installation.

The Changes in Contrast Sensitivity and Glare Sensitivity when Wearing Circle Contact Lenses after the Refractive Surgery (시력교정술 후 써클콘택트렌즈 착용 시 대비감도 및 눈부심감도 변화)

  • Kwon, Ki Nam;Park, Sang Hee;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.21 no.1
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    • pp.23-34
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    • 2016
  • Purpose: In the present study, the effect of circle contact lenses wear on contrast sensitivity and glare sensitivity in a refractive surgery group was investigated. Methods: The contrast sensitivity and glare sensitivity were evaluated using by CGT-1000 for a non-refractive surgery group as control group(40 eyes) and a refractive surgery group(30 eyes) applied plano circle contact lenses, and pupil size was also measured. The correlation between contrast/glare sensitivity and the pupil size was analyzed. Results: In the refractive surgery group, contrast sensitivity in the range of high spatial frequency decreased with wearing circle contact lenses, and amount of decrease for the refractive surgery group was larger than for the control group. The correlation between pupil size and the change of contrast sensitivity was decreased by wearing circle contact lenses, and the correlation was lower in the refractive surgery group than the control group. Furthermore, the wear of circle contact lenses affected on glare sensitivity. In analyzing the change of glare sensitivity by pupil size, the glare was larger in the refractive surgery group than control group. Circle contact lenses in refractive surgery group were not fitted on the center of cornea. Conclusions: In the present study, it is suggested that the sufficient understanding and consideration about the decrease of contrast sensitivity and the increase of glare by wearing circle contact lenses after the refractive surgery is necessary.

Evaluation of Glare and Forward Visibility of Headlamp for Elder Friendly Vehicle (고령자용 자동차 전조등의 눈부심 및 시인성 평가)

  • Kang, Byung-Do;Kim, Hyoung-Gu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.4
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    • pp.1-6
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    • 2011
  • The elder population with 65 years old or more in Korea has been entered into an aging society as 9.1[%] in 2005 to 14.3[%] in 2018. The elder population in 2026 will be expected to 20.8[%] with the rapid aging society. In this study, there has been conducted a study on development of headlamp for elder friendly vehicle in order to ffrom two different groups, one group for elder with over 65 ages, the other group for compared ages(20 ages, 30~50 ages). Glare test and forward visibility test were performed on wet and dry road conditions. As the result of these tests, it showed to prefer headlamp installed partially yellow coated bulb, which gives warm feeling on dry road condition. Forward visibility of headlamp which developed to fit on wet road condition is similar to existing HID headlamp. Glare was evaluated less than halogen and HID headlamp. However, it need to more improve glare and forward visibility performance of headlamp for old drivers.

Optimum Blind Control to Prevent Glare Considering Potential Time Error (잠재적 시간 오차에 따른 현휘의 발생 방지를 위한 최적 블라인드 제어)

  • Seong, Yoon-Bok
    • Journal of the Korean Solar Energy Society
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    • v.32 no.2
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    • pp.74-86
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    • 2012
  • For the improvement of environmental comfort in the buildings with the blind control, the objective of this study is to prevent the direct glare caused by the daylight inlet. During the process of solar profile prediction, time are significant factors that may cause error and glare during the blind control. This research proposes and evaluates the correction and control method to minimize prediction error. For the local areas with different longitude and local standard meridian, error occurred in the process of the time conversion from local standard time to apparent solar time. In order to correct error in time conversion, apparent solar time should be recalculated after adjusting the day of year and the equation of time. To solve the problems by the potential time errors, control method is suggested to divide the control sections using the calibrated fitting-curve and this method is verified through simulations. The proposed correction and control method, which considered potential time errors by loop lop leap years, could solve the problems about direct glare caused by daylight inlet on the work-plane according to the prediction errors of solar profile. And also these methods could maximize daylight inlet and solar heat gain, because the blocked area on windows could be minimized.

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.

A Study on Simulation of Daylight for Reducing Glare of the Lecture Room's Front Side in University (대학강의실 전면현휘 감소를 위한 주간채광유입 시뮬레이션에 관한 연구)

  • Jeong, Ji-Seok
    • Journal of the Korean housing association
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    • v.24 no.3
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    • pp.1-8
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    • 2013
  • The University students learn their major or a general education in lecture rooms. In these days, lecturer use frequently various multimedia in lecture room. Appropriate control lighting environment in lecture room should be essential and related in efficient studying. Daylighting on front-side of lecture room will cause glare and students are hard to read contents on white-board at their seat. Therefore, in order to preventing glare we simulated daylighting of lecture room with using computer software in this study. Results from simulation and analysis as follows: The first, if students' left-side is east-oriented in lecture room, best daylighting condition about glare in lecture room. The second, architectural designers can use simulation data of daylighting or simulate data in designing university buildings with lecture rooms. Finally, if reducing size of windows (narrow and deep daylight: more closing vertically, from up to down daylighting: more closing horizontally) we will be able to reduce energy from lecture room.

Investigating the deflection of GLARE and CARALL laminates under low-velocity impact test, experimentally and FEM simulation

  • Meisam Mohammadi;Mohammad Javad Ramezani
    • Steel and Composite Structures
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    • v.47 no.3
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    • pp.395-403
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    • 2023
  • The main objective of this article is to investigate the response of different fiber metal laminates subjected to low velocity impact experimentally and numerically via finite element method (FEM). Hence, two different fiber metal laminate (FML) samples (GLARE/CARALL) are made of 7075-T6 aluminum sheets and polymeric composites reinforced by E-glass/carbon fibers. In order to study the responses to the low velocity impacts, samples are tested by drop weight machine. The projectiles are released from 1- and 1.5-meters height were the speed reaches to 4.42 and5.42 meter per second and the impact energies are measured as 6.7 and 10 Joules. In addition to experimental study, finite element simulation is done and results are compared. Finally, a detailed study on the maximum deflection, delamination and damages in laminates and geometry's effect of projectiles on the laminate response is done. Results show that maximum deflection caused by spherical projectile for GLARE samples is more apparent in comparison with the CARALL samples. Moreover, the maximum deflection of GLARE samples subjected to spherical projectile with 6.7 Joules impact energy, 127% increases in comparison with the CARALL samples in spite of different total thickness.

A Study on the Visual Impairment of Pilots and Controllers caused by Large Lighting Facilities around Airports during Nighttime Flight Operation (야간운항 중 공항 주변 대형 조명시설에 의한 조종사와 관제사의 시각장애현상에 대한 연구)

  • Jong-jin Jeon;Hyun-seung Lee
    • Journal of Advanced Navigation Technology
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    • v.25 no.6
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    • pp.466-475
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    • 2021
  • Airport-related laws restrict the installation of lights that obstruct the identification of airport lights or cause glare to pilots and controllers around the airport. However, with regard to the glare that lights give to the pilot or controller, it is only judged whether there is a limit based on a qualitative judgment, and a quantitative review has not been made. Therefore, in this study, visual disturbances that may occur to pilots and controllers due to large lighting facilities around airports during nighttime flight operation were quantitatively calculated and confirmed through disability glare, object recognition, and identification obstruction. And based on this study, it was suggested to supplement the related system to prevent the visual impairment of pilots and controllers caused by lighting facilities.

Acceptable Luminance Levels of a LCD TV Based on Glare of Human Visual System

  • Kim, Ki-Duk;Ahn, Ji-Young;Yoon, Jae-Kyung;Shin, Hyun-Ho;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.125-128
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    • 2005
  • The visual perception tests were conducted to determine limits of luminance of a LCD TV from a viewpoint of glare. The results showed that people, who watch TV in their living room, perceive glare above $410\;cd/m^2$ at full window and $590\;cd/m^2$ at 1/25 window.

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