• Title/Summary/Keyword: Daylight illumination

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주광을 활용한 LED조명시스템의 컨트롤에 관한 실험적 연구 (An Experimental Study on Control Strategy of LED System Using Daylight)

  • 윤경;윤갑천;김강수
    • KIEAE Journal
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    • 제10권6호
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    • pp.33-39
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    • 2010
  • Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

천창루버에 의한 내부공간 바닥면 조도변화와 설치방식에 관한 연구 (A study of Illumination on Floor Surface by Flat Form Louver of Top Lighting System)

  • 김미희;태원진
    • 한국태양에너지학회 논문집
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    • 제31권6호
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    • pp.132-138
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    • 2011
  • Inducing the natural lighting into building has been commonly applied to the spaces where artistic objects are displayed to create better visual environment for the appreciation. The direct natural lighting, especially through top lighting system may, however, bring forth discoloing of highly light-sensitive materials such as paintings or demanding additional cooling load. In addition, it causes to create glare against appreciators or to yield in visual distraction due to the extreme contrast on the inner surfaces of the spaces. Shading device such as louver is capable of preventing such voidable cases with careful manipulation. This study aims to provide basic design guide-line when the flat-form louver has to be applied to top lighting system. Interaction between the daylight and louver was simulated by Reluxpro program with variation of the attachment location, the angle of the lover, surface reflectivity, to obtain the illumination of the floor surface. This study yields the louver just under the top lighting window with 90 degree angle gives the most desirable way of employment when the uniform illumination on the floor surface is required.

통합 채광시스템의 건물 냉난방 에너지 성능평가 (Building Energy Savings due to Incorporated Daylight-Glazing Systems)

  • 김정태;안현태;김곤
    • 조명전기설비학회논문지
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    • 제19권6호
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    • pp.1-8
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    • 2005
  • 건물 내에 존재하는 자연광은 조명원으로 국한되지 않고 시각적, 심리적 자극을 통한 실내 환경의 질적 향상에 이르기까지 에너지절약 및 공간의 쾌적성에 큰 영향을 미친다. 유입되는 자연광량에 비례적으로 연동되는 건물에너지는 전기조명에너지를 절감시키고 난방 기간동안 일사열의 유입에 따른 난방에너지를 절감시킨다. 여름철에는 전기조명의 소등으로 인한 조명원의 발열량이 감소됨으로써 냉방부하의 감소에 이르기까지 포괄적인 영향을 미친다. 조명개발분야의 선진국에서는 에너지 절약형 광원의 대체와 아울러 자연채광과 통합된 최적 조명제어 기술의 운용만이 건물이 가지고 있는 에너지 절약의 잠재력을 현실화시킬 수 있다고 판단하고 있다. 따라서 본 연구는 일반적인 사무소 모델 공간의 에너지 절약형 인공조명을 대상으로 자연광 유입에 따른 연동적 조명제어 기법을 적용하는 경우를 대상으로, 인공조명의 소등량에 따른 조명에너지의 절감량과 이에 수반되는 냉방에너지의 점감량 및 일사열 취즉에 따른 겨울철 난방 부하 절감량을 분석함으로써 자연채광의 건물에너지에 대한 연간 기여도를 통합 분석하였다. 특히 자연채광의 성능은 실험을 통한 측정 데이터를 이용하고 에너지 해석 프로그램을 재구성하여 실질적인 절감량을 도출하도록 시도하였다.

Color Image Enhancement by Fundamental Vector Transformation and Nonlinear Mapping

  • Kim, Kyeong-Man;Lee, Cheol-Hee;Lee, Chae-Soo;Ha, Yeong-Ho
    • Journal of Electrical Engineering and information Science
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    • 제3권3호
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    • pp.330-335
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    • 1998
  • In this paper, a new light-value approaching method to enhance a color image by excluding the effect of incident illumination is proposed. The method uses the fundamental vector transformation in which an estimated color of illumination is rotated to the white color of natural daylight. Then the transformed red, green, and blue values of each pixel are nonlinearly mapped into the 8-bit values to enhance intensity and saturation in the dark portion of the image. The proposed algorithm can produce the enhanced color image fast and efficiently without any space conversion or noticeable distortion.

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자연채광을 이용한 인공조명의 제어방법에 관한 실험적 연구 (A Experimental Study on Artificial Illumination Control System Illuminated by Daylighting)

  • 차광석;김회서
    • 한국조명전기설비학회지:조명전기설비
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    • 제8권1호
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    • pp.21-28
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    • 1994
  • 기존 상업용빌딩은 실내 시환경 개선의 필요성이 중시됨에 따라서 자연채광과 인공조명을 겸용하는 천장형태에 따른 조명제어 방법으로 전기에너지도 절약하면서 실내의 작업면 조도는 적정조도를 이루게 하는 방안을 찾고자 한다. 이에 본 논문에서는 창 유리의 종류와 실내의 마감색채, 천장타입에 따른 인공조명의 제어방법을 가지고 실험을 하였으며, 실험한 데이터는 실내의 조명설계시 참고할 수 있는 기초적 자료로 제시하고자 했다.

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터널의 조명환경 개선을 위한 반사거울 시스템의 위치 선정에 관한 기초연구 (A basic study on the location of mirror reflector system to improve illumination environment)

  • 정명순;주재성;정인영;송규동
    • 한국터널지하공간학회 논문집
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    • 제13권5호
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    • pp.385-393
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    • 2011
  • 경제성장의 달성과 직선도로의 증가에 따라 터널은 전보다 더 많이 만들어졌다. 이러한 터널들의 입구 조명은 안전하고 편안한 운전을 위해 중요하다. 대부분의 터널 조명은 인공조명으로 많은 에너지를 사용한다. 본 연구에서는 터널의 조명 개선과 에너지 절약으로 반사거울 시스템을 적용하여 평가하였다. 반사거울 시스템을 적용하면 주광을 유입하여 터널 조명 환경을 개선할 수 있으며, 본 연구는 터널 인공조명 에너지의 절약을 위한 선행연구의 일환으로 진행되었다.

교사환경기준에 관한 연구 (A Study on Environmental Standards of School Building)

  • 홍석표;박영수
    • 한국학교ㆍ지역보건교육학회지
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    • 제1권1호
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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AVR Microcontroller를 이용한 하이브리드 자연채광시스템의 성능에 관한 기초연구 (A Study on the Performance of a Hybrid Daylighting System Using AVR Microcontrollers)

  • 임상훈;오승진;김원식;정해준;천원기
    • 한국태양에너지학회 논문집
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    • 제35권6호
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    • pp.1-7
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    • 2015
  • This paper deals with the design and operation of a hybrid daylighting system that uses natural and artificial lighting to enhance visual comfort in buildings. The system was developed using an AVR micro controller for solar tracking in conjunction with dimming controls, which, acting together, enables the maximum use of natural daylight and also improves energy efficiency in buildings. Experimental results clearly demonstrates the usefulness of the present system capable of enhancing indoor lighting conditions when sufficient daylight is available and distributed appropriately in harmony with artificial lighting.

사무공간 적용 BIPV시스템의 자연채광 및 성능평가에 관한 연구 (A Study on Evaluation of Daylighting in Office Space Applied BIPV Systems in Accordance with Power Performance)

  • 서영석;오민석;김회서
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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    • pp.148-154
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    • 2009
  • By the skyscraper building, increase of skin area and expansion of curtain wall system will be the important factors of acceleration in extending supply of BIPV system. In the future interior environmental evaluation is not a necessary to the residents but an essential term which will bring enormous influence. In the interior environmental evaluation, natural light will let the residents with direct contact with outside circumstances and make them feel opened. also only the daylight has radiant energy and color rendering that will have a great influence to residents' mental, operation efficiency and advancing productivity. This research compares and analyzes BIPC system in office spaces with two general sunlight's module. In addition to natural light's efficiency for BIPC system's comfort and confirmed economical efficiency will be applied to basic research data. Hence forth, ensuring indoor intensity of illumination and controlling light system to reducing energy research data will be demanded to increase the amount of supplying BIPC system. Also continuance research in the possibility of applying BIPC system in various buildings, room temperature affected by location of windows and its condensation, and economical evaluation will be required.

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Air Pressure Regulation in Air Bladders of Ascophyllum nodosum(Fucales, Phaeophyceae)

  • ;강은주
    • ALGAE
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    • 제21권2호
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    • pp.245-251
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    • 2006
  • Diurnal and age-related changes in air pressure were measured in air bladders of Ascophyllum nodosum from the Atlantic coast of Nova Scotia. Exterior and interior bladder volumes vary significantly with 4 and 6 y bladders being about 40% larger than 2 y bladders (p < 0.01). Freshly collected bladders yielded a mean pressure of 40.8 ± 6.5 cm H2O. Overnight (20 h) dark treatment at 15°C generated pressure reductions by 80% in 2 y bladders but only by about 30% in 4 and 6 y bladders. Furthermore, in 2 y bladders 8 out of 11 bladders were reduced to atmospheric pressure. Pressure losses were inversely related to pressure recovery after 2.5 h in natural daylight, but after 5 h in daylight there was no significant difference in pressure within the age groups. Even under 25% of full illumination, bladders inflated to full pressure after 5 h. The results show that differences in bladder age and bladder wall thickness have roles in diurnal patterns of bladder inflation and deflation. These results confirm that bladder inflation is based on photosynthetic O2 production and not on partial pressures of O2 in the surrounding medium as was suggested for Sargassum. Chemical analyses of fluid recovered after the interior of bladders were washed with saline showed no evidence for the occurrence of surfactant that might be responsible for maintaining the air-liquid interface.