• 한국태양에너지학회 논문집
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• 제32권6호
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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.

• 한국태양에너지학회 논문집
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• 제32권spc3호
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• pp.199-206
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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 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, the two variables were used in this study. 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.

• 조명전기설비학회논문지
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• 제17권4호
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• pp.13-19
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• 2003

학교 교실 조명은 교사와 학생들에게 쾌적한 명시 환경을 주어 시력 보호와 학습 효과의 향상을 도모하는데 매우 중요한 역할을 하고 있다. 이러한 교실 조명 환경의 향상을 도모하기 위한 방법으로 칠판등 개발이 이루어지고 있다. 본 논문에서는 칠판면에 일정한 조도를 제공하고 효율이 높은 칠판등용 경면 반사판 형상을 설계하는 과정을 설명하였다. 이러한 과정에서 크기가 있는 광원에 의한 설계상의 문제점을 고찰하고자 한다.

• 한국광학회지
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• 제31권4호
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• pp.183-190
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• 2020

본 논문에서는 넓은 조사 면적에 단거리 조사시에도 균일한 조명도 분포를 가지도록 하는 비대칭 배광의 조명 광학계에 대한 연구를 진행하였다. 단거리에 설치되는 조명의 경우 조사 거리가 짧기 때문에 충분한 배광 분포 형성이 되지 못해 조명의 균일도를 만족하기 어렵다. 또한 시인성을 위해 조명기기가 기울어져 설치되기 때문에 비대칭 배광의 조명 설계가 요구된다. 이러한 문제점을 해결하기 위해 비대칭 배광을 가지는 조명 광학계 설계를 통해 근거리 조사 시에도 대상 표면에 균일한 조명도를 얻을 수 있었으며, 이를 근거리 조명 중 하나인 라이선스 램프에 적용하여 법규 기준을 만족하는 것을 확인하였다.

• 전기학회논문지
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• 제65권1호
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• pp.158-164
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• 2016

That's the reason why LED lighting has to employ AC power inlet. However, LED is a kind of diode, semiconductor, it's driven by DC power. With whis reason all of LED lighting should have AC/DC converter in its systems. This converter causes energy loss, it's the target for lesson the energy loss. To reduce this energy loss, DC power distribution structure can be used. LED lighting system using LVDC is a kind of DC power distribution structure, but LVDC has severe voltage drop which makes non-uniform brightness in lighting system. In this paper, we suggest a novel structure for the uniform brightness in LVDC LED lighting system using IoT based network system. The constructed test-bed system of suggested structure shows this structure can con control the brightness with uniformity.

• Transactions on Electrical and Electronic Materials
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• 제18권1호
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• pp.35-41
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• 2017

This study looks at optimizinge light redistribution to improve the overall illuminance uniformity of commercial IRED modules. To obtain uniform illumination over a prescribed rectangular area, a freeform surface lens was evaluated using TracePro. The LED light overall illuminance uniformity regulated in KSC 7658 was verified using Relux software. Experimental test results showed 0.81 overall illuminance uniformity for rectangular light distribution of LED lights having a radiation angle of $80^{\circ}$. After fabricating prototype IRED lights based on these simulation results, illuminance performance was observed when used as actual IRED lighting with a nighttime CCTV system. Image observation photographs of the prototype $80^{\circ}$ rectangular IRED lights confirmed that object images can be seen clearly owing to high overall illuminance uniformity, and that dark regions of the CCTV screen were not shown.

• 설비공학논문집
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• 제24권5호
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• pp.443-453
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• 2012

This study examines visual perception and spatial satisfaction according to lighting conditions. Field measurements and surveys were performed in three rest space of university buildings where various lighting conditions were employed. Results indicate that overall impression of space improved when low color temperature, such as 3,000 K governed overall lighting environment and accent lighting was used for wall surfaces. Lighting conditions that kept uniform illuminance levels using area light sources containing fluorescent lamps with 6,500 K failed to keep favorable spatial satisfaction for space. High color temperature was not recommended for lighting in rest space. Asymmetrical illuminance levels formed by low color temperature such as 3000 K is recommended to keep positive mood and improve spatial satisfaction in rest space. Overall impression of the space was influenced by visual comfort, color temperature, spatial satisfaction and brightness. Spatial satisfaction for space was effectively impacted by psychological comfort, color temperature and overall impression for lighting conditions. Psychological comfort in space was influenced by color temperature, spatial satisfaction and visual annoyance from reflected light.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.13-17
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• 2013

In lighting system where several large-area organic light-emitting diode (OLED) lighting panels are involved, panel aging may appear differently from each other, resulting in a falling-off in lighting quality. To achieve uniform light output across large-area OLED lighting panels, we have employed an optical feedback circuit. Light output from each OLED panel is monitored by the optical feedback circuit that consists of a photodiode, I-V converter, 10-bit analogdigital converter (ADC), and comparator. A photodiode generates current by detecting OLED light from one side of the glass substrate (i.e., edge emission). Namely, the target luminance from the emission area (bottom emission) of OLED panels is monitored by current generated from the photodiode mounted on a glass edge. To this end, we need to establish a mapping table between the ADC value and the luminance of bottom emission. The reference ADC value corresponds to the target luminance of OLED panels. If the ADC value is lower or higher than the reference one (i.e., when the luminance of OLED panel is lower or higher than its target luminance), a micro controller unit (MCU) adjusts the pulse width modulation (PWM) used for the control of the power supplied to OLED panels in such a way that the ADC value obtained from optical feedback is the same as the reference one. As such, the target luminance of each individual OLED panel is unchanged. With the optical feedback circuit included in the lighting system, we have observed only 2% difference in relative intensity of neighboring OLED panels.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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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.

• 한국주거학회논문집
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• 제18권1호
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• pp.35-42
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• 2007

This study aims at examining the actual conditions of lighting environment and the consciousness and responses of residents with the living room of apartment house, grasping the problems of existing lighting methods, offering the lighting environment design standard in harmony with the various demands of residents, functions of living room space, life in living room and interior decoration and then pursuing the comfortable living environment. As the scope and methods of research for these, existing research methods are examined through the consideration of preceding researches and the basic outline of this research is constructed. Questionnaire survey is conducted with six apartment complexes including Kumho district, Munhung district, Sangmu district, Unnam district, Ilkok district and Chumdan district, the problems and improvements of lighting environment conditions are examined, conception and selection of lighting equipment design image are made, lighting equipment design of living room is suggested and the expected effects of lighting equipment ordering method are arranged as follows. As a result of examining and analyzing the lighting environment of living room in existing apartment houses, it is known that the conditions of existing lighting environment considered uniform lighting plan for functional sides of each room which didn't consider the various living behaviors and preference of residents and while the degree of interior decoration design is actually positive. Accordingly it seems that the lighting equipment ordering which considers the various preferences of residents is applied as the means for comfortable lighting environment, the interior environmental mood will be greatly improved.