• Title/Summary/Keyword: Illuminance difference

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Visual Performance Evaluation Study of a Scaled Light-Shelf Model (축소모형을 이용한 광선반의 시환경 특성 평가 연구)

  • Cho, Yil-Sik;Kim, Byoung-Soo;Lee, Jin-Sook
    • Journal of the Korean Solar Energy Society
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    • v.23 no.3
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    • pp.63-71
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    • 2003
  • According to the recent report, the lighting energy consumption of commercial buildings reaches to $30%\sim40%$ of the total energy consumption. It is more than that of cooling & heating energy consumption and it is the major target of energy-saving policy. It is obvious that they are interested in natural lighting device such as Light-shelf for the purpose of raising the lighting energy-saving efficiency. In most of highly developed countries, a thorough study on Light-shelf makes it possible to propose a practical plan while at home there leaves much to be desired to study a guiding principle of optimum plan in spite of its efficiency based on experiments using scale4 model and analysis of simulation. Aiming at making an optimum plan of Light-shelf suitable for the domestic situation, this study is worked by experiments using light-shelf and analysis of variables using illumination program. The experiments is to analyse the efficiency of Light-shelf on condition of the sky and the analysis is to make the simulation using illumination program. This study is composed of 1) the analysis of light with some variables such as presence of light-shelf and degree of angle using 1/2 scaled model 2) making the simulation using Lightscape, illumination program, In brief, concerning presence of light-shelf, it causes little difference in its efficiency in the overcast sky, whereas it decreases an illuminance of window side and provides inner side with the light, which decreases the ratio of the maximum to the minimum inner illuminance and makes the inner of illuminance to range evenly in the clear sky. On degree of angle, as the daylight increases in proportion of degree of angle, the ratio of the maximum to the minimum inner illuminance decreases, which makes it possible to increase the proportion of inner daylight.

Analysis of Fish Blocking Effect using Illuminance Difference (조도 차이를 이용한 어류 차단 효과 분석)

  • Kang, Joon-Gu;Kang, Su-Jin;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.76-83
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    • 2017
  • Fish respond sensitively to light, so it is possible to develop fish management technology using this feature. In this study, we developed a light-based fish barrier and analyzed itsblocking effect using the difference in illuminance for the major fish species in Korea, bass and bluegill. The light was generated by a light emitting diode and the facility was installed vertically from the bottom. Considering the fish's ability to travel upstream, the flow rate was divided into three stages (0.2, 0.1, and 0.05 m/s). To prevent the learning effect, an experiment was carried out with fish that had rested for more than one day in a rearing tank. The experiment was carried out in such a way as tocompare the number of fish which travelled upstream after the introductionof the fish barrier and that of the fish which travelled upstream after itsremoval. It was also carried out after sunset to increase the effectiveness of the barrier. According to the results of the experiment, the fish blocking effect depending on the difference in illuminance was high and, overall, the blocking rate for bass was lower than that for bluegill. Based on the total size of the experimental population, the blocking rates for bass and bluegill were 96.33% and 99.00%, respectively. Based on the number of fish that travelled upstream, the blocking rates for bass and bluegill were 91.73% and 98.73%, respectively.

A Study on the Actual Condition of Illumination Environment in Public Libraries in Daegu

  • Seo, Ji-Eun;Kim, Hyun-Ji;Kim, Sung-Hwa;An, Ok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.3
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    • pp.1-9
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    • 2009
  • This study investigated the actual condition focusing on the lighting environment which is a major element in aspect of indoor environment of a public library and assessed user satisfaction. Research results are as follows: Firstly, numbers of lighting fixtures per dimension of a reading room in a public library were inconsistent due to the lack of definite regulations, which was found to have negative effect on night time illuminance. Secondly, it was assessed that illuminance between the day time influenced by natural lighting and in the nighttime without natural lighting has more than 10-fold difference. Therefore, such a condition is judged to be inappropriate for lighting environment of a reading room where users spend a long time studying and thus, it is considered that an appropriate measures should be taken. Thirdly, as the survey result on users' satisfaction with lighting environment was revealed to be lesser than 3 points, lighting plan in consideration of its users should be progressed.

The Combined Environmental Factors on the Human Physiological and Psychological Responses in Indoor Space (실내공간의 복합 환경 조건이 인체의 생리 및 심리반응에 미치는 영향)

  • Yoon, In
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.3
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    • pp.87-94
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    • 2012
  • Kruithof demonstrated the preferred combination of illuminance levels and color temperatures. However, as Benett pointed out, difference of themal variables in such preference may be expected. The purpose of this study is to clarify the combined effects of lighting conditions(illuminance, color temperature), operative temperature on the human physiological and psychological responses. In order to observe operative temperature change in preference of color temperatures for three illumination levels, three subjects were exposed to two different conditions of color temperatures of 2,850K, 4,200K and 6,850K combined with operative temperatures(OT) of $25{\sim}31^{\circ}C$ at 100~1000lx. Thermal sensation vote and comfortable sensation vote, brightness perception vote were reported in each experiment conditions. The following results were obtained : 1) When illuminace level was at 100lx in operative temperatures of OT $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, Color temperature affect not themal sensation but Warm-cool sensation. 2) Operative temperatures affect not brightness perception vote but visual comfort sensation vote, satisfactive sensation vote, warm-cool sensation vote and themal sensation vote.

Energy consumption by Spectral Power Distribution Of LED lighting (LED 조명의 분광 분포에 따른 건물에너지 소비)

  • Jung, Ho-Youn;Kim, Hyo-In;Kim, Gon;Yun, Geun-Young
    • KIEAE Journal
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    • v.12 no.3
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    • pp.101-106
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    • 2012
  • Lighting energy accounts for approximately 20% of the electrical energy used worldwide. Thus, High efficiency Light emitting diode(LED)lighting is getting more popular as the next generation lighting replaced to traditional lighting fixtures. Also, LED lighting not only has a long lifetime but also can realize a variety visual environments through the wavelengh control. The lighting energy varies depending on the Spectral Power Distribution(SPD) even though the Illuminance level is same. Therefore, This study indicates that the difference of indoor energy consumption under the same illuminance level when Spectral Power Distribution(SPD) is different. As a result, Lighting energy consumption under red-color emphasizing SPD is about 10% lower than under blue-color emphasizing SPDs.

A Study on Visual Comfort for Light Control Method of Applied Daylighting (자연채광방식의 응용에 따른 시각적 쾌적성에 관한 연구)

  • Han, Sang-Pil;Han, Sang-Cheol
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.140-145
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    • 2012
  • The purpose of this study is to understand the change of impression by comparing the uniformity lighting with the compound lighting. In previous study, we proposed a light controlling method to harmonize daylight from a window and artificial lights from a ceiling and obtained the results to support our method. We referred this method as the Adjusted Compound-Lighting Model (AC Model). The model claims that lighting in a room with a side-window are perceived as harmonious when the overall light distribution in the room is well approximated by a compound of lights from the window and the entire ceiling. The experiment is carried out with the scaled-models and mock-up spaces that were supposed to be an office space. One is lit by the uniform lighting and the other by the compound lighting in each experimental space. In order to present varying illuminance distributions, thetwo variables were used in this study. One was the ratio of thelight from the window and ceiling in the standard and evaluation box. The standard box was provided by the ratio of 20% to 40% from the window and 80% to 60% from the ceiling as two lighting ratio patterns [Wu20(=Cu80) and Wu40(=Cu60)]. And the evaluation box was provided by the light ratio of 0% to 40 from the window and 100% to 60% from the ceiling [Wcp0(=Ccp100), Wcp20(=Ccp80) and Wcp40(=Ccp60)]. The other variable was themean illuminance level in both boxes. Two level of mean illuminance (700lx and 300lx) were used in this experiment. Each lighting condition was established at equal horizontal mean illuminance level, held constant near 700lx or 300lx in both boxes. Both of them were similar in the shape of distribution when there were same ratios of lights from the window and the ceiling. Subjects were asked to evaluate the point of difference by semantic differential rating on their overall impression after comparing with two rooms. The results showed that the impressions of compound lighting were more positive score than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open', and that there was no significant difference in impressions between two spaces on other items.

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Evaluation for the cognition and usability of HUD while driving (주행 중 운전자의 HUD 인지성과 활용성 평가)

  • Yun, BoRam;Park, DaEun;Kim, BoKyung;Cho, JuYung;Park, YungKyung
    • Science of Emotion and Sensibility
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    • v.17 no.3
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    • pp.117-128
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    • 2014
  • As the main cause of car accidents is driver distraction, HUD utilization is important to boost drivers' front-observing. Recently, As HUD includes a variety of contents products have appeared on market, the possibility increases cognitive load while driving. The purpose of this study is that currently being used HUD contents how much affect drivers while driving. To investigate about it, the experiment is examined cognitive aspect with utilization aspect of different gender and illuminance environment. The study provides, in accordance with the internal and external illuminance, the visibility make a difference. The gap between the internal and external illuminance is higher, the visibility is better. Also, this study confirms that HUD's awareness of contents depends on driving information. Drivers concentrate more on higher related driving contents than lower ones.

An Approach to the Design of Museum Luminous Environment (박물관의 조명환경 계획에 대한 소고)

  • Kim, Hong-Bum
    • 보존과학연구
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    • s.16
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    • pp.139-154
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    • 1995
  • In this paper the fundamental elements relevant to schematic daylighting design for museum are discussed and suggested. The illuminance difference between outdoor and exhibition space in consideration of the constraints necessary for the conservation of artifacts can be solved by conversion into Luminance. Also it is considered that transition zone in two stages should be provided for adaption before entering exhibition space and overall luminance within the visual field along viewing circulation should be balanced including the apertures designed for introducing the daylight or visual linking.

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Experimental Evaluation of the Lighting Environment for Main Activities of the Residents in Living Room (거실 거주자의 주요 행위에 적합한 조명환경 평가 실험)

  • Kim, Hyun-Ji;Woo, Seong Jun;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.9
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    • pp.6-14
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    • 2013
  • The position of the light source, illuminance distribution, and color temperature were evaluated in each lighting environment for the three main activities in a living room - 'watching TV,' 'reading' and 'relaxing.' In 'watching TV', the experiment was done to estimate the degree of comfort felt by the subjects when they watch static video and moving video, respectably, with different ambient brightness, with or without partial lighting above the TV set, and with different color temperatures. In 'reading', the comfortableness was estimated by the illuminance ratio of the ambient lighting to the lighting for reading and by the difference in color temperature. And in 'relaxing', the comfortableness was estimated by means of the ambient brightness, use/no use of a relaxing lamp, and color temperature. This experiment determined the general satisfaction for each visual act and the optimum lighting environment to reduce glare.

The Availability Examination for Vegetation Measurement of The SLR Digital Camera (SLR 디지털카메라의 식생관측센서로서의 유효성 검토)

  • Kim, Jong-Hwan;Kim, Eung-Nam;Jun, Byung-Dug;K., Sugiyama
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.1
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    • pp.683-692
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    • 2009
  • On-site remote sensing technique by using single lens reflex(SLR) digital camera will be expected as the useful tool for the vegetation measurement field such as a crop growth management, the monitoring of revegetation slope and the evaluation of environment. We reviewed the availability of the vegetation measurement using a digital camera which is sailed for general-purpose. As a result, we could analysis relationship with the illuminance of image plane and incidence energy of multitemporal observation images by doing gamma correction and exposure compensation. And also, we proposed the model formulas for the correction of influences of capturing angle and illuminance. In addition, we obtained high correlation of normalized difference vegetation index(NDVI) between digital camera and spectral photometer.