• 한국터널지하공간학회 논문집
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• 제14권1호
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• pp.93-105
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• 2012

대부분의 터널 조명은 인공조명에 의존하고 있어 조명설비의 유지관리비 및 전력비를 절감하기 위해 자연채광을 적용한 기초연구가 선행되었다. 이에 본 연구는 터널 조경 바형식 반사거울시스템의 채광성능(조도, 휘도)을 평가하였다. 수평면 조도를 측정한 결과, 전체 평균 1,170 lx로 미설치 대비 6.5배 이상 증가하여 채광유효구간에서 구간별 터널기준조도(KSA 3703)를 만족시키는 것으로 나타났으며, 터널 밖으로 나오는 반대편 차로 운전자의 휘도를 측정하여 분석한 결과, 전체 평균 3.01로 현휘 기준치인 10 이내로 평가되어 눈부심이 발생하지 않는 것으로 나타났다.

• 한국태양에너지학회 논문집
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• 제23권3호
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• pp.93-102
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• 2003

One of the promising optical daylighting systems is light shelf type daylighting system, Two types of lighting performance analysis methods are 1) Ray-Tracing method and 2) Radiosity method. The purpose of this paper is to compare two methods in terms of advantages and disadvantages by further looking at the detail algorithm. Also. model verification with Lightscape simulations has been conducted. Effectiveness of light penetration factor in terms of daylighting factor has been investigated and quantified. In summer time. the performance of the light shelf was twice better than the case without it.

• 마이크로전자및패키징학회지
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• 제21권3호
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• pp.37-41
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• 2014

본고에서는 태양광 조명 시스템 중 태양을 추적하며 오목한 형태의 반사경으로 태양광을 집광하고, 전기에너지로 변환과정 없이 그대로 조명으로 사용하는 시스템의 효율 향상에 관해 다뤘다. 반사경 및 렌즈들의 초점거리, 위치 등에 따라 시스템 전체의 효율이 크게 좌우되고, 제품의 조립 및 제작 과정, 외적 환경요인 등에 의해 렌즈 및 거울간의 정렬 상태가 집광효율에 상당한 영향을 준다. 시뮬레이션을 통해 최대효율을 내기 위한 convex lens의 위치를 확인하였다.

• 한국태양에너지학회 논문집
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• 제28권3호
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• pp.27-34
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• 2008

A series of outdoor tests were conducted on a fiber optic solar concentrator system for its performance on daylighting. The system is comprised of four main components - a parabolic dish reflector, a convex mirror, a homogenizer tube and an optical fiber cable. Results show that the system could be successfully applied for indoor lighting if some improvements are made for light transmiting (optical) cables. A maximum concentration ratio of 90 was observed delivering the illuminance of 4,800 lux at a distance of 1.2m from the diffuser for the outdoor illuminance of 102,100 lux.

• KIEAE Journal
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• 제8권1호
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• pp.45-52
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• 2008

Daylighting systems can improve the luminous quality of indoor environment and reduce the building's electric lighting energy consumption. For designing good daylighting, place the light where it is desired and avoid excessive contrasts, glare and high light levels. Sun scoop, light scoop and sun catcher systems have been used for alternative systems compared to other natural lighting systems. This study aims to evaluate daylighting performance of sun scoop, light scoop and sun catcher systems using scale model experiments. For the purpose, the 1/10 scale models of the systems were made as the same areas of glazing(10 percent of floor area) on the top of the center roof. Totally 15 measuring points of illuminance on the horizontal work plane were monitored from 09:30 to 12:30 on October 29, 2007. Agilent data logger and photometric sensors Li-cor were used. As the results, the topside lighting systems can improve the illumination uniformity than side lighting and top lighting. However, the appropriated shading system should be integrated to prevent the direct sunlight.

• 한국태양에너지학회 논문집
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• 제29권1호
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• pp.11-17
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• 2009

Daylighting is core of sustainable design in most buildings. Well-designed daylighting systems can significantly reduce or even eliminate the electric lighting loads during the day time, including air conditioning energy loads. Among window systems. the topside lights systems including monitor lighting, sawtooth lighting, sunscoop and, lightscoop is one of the most popular apparatus to improve the lighting quantity. Also they are important both in terms of energy savings and visual quality. The objective of this study is to analyse daylighting performance of topside lighting system for different orientations. Four types of topside lighting system were tested and comparpd: monitor lighting, sawtooth lighting, lightscoop and sunscoop. Totally 25 measuring points of illuminance on the horizontal plane were monitored from 09:00 to 17:00 on October 6, 2008. Agilent data logger and photometric sensors Li-cor were used. Comparisons with a light factor is discussed. The results found in this study would mean that there were no significant differences in light factor between three cases.

• KIEAE Journal
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• 제5권3호
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• pp.3-9
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• 2005

Venetian blinds are used with windows to improve the uniformity ratio of illuminance and interior daylighting distribution under direct sunlit conditions. The main objective of Venetian blinds shading system is to obstruct direct sunlight and at the same time allow daylight to penetrate into the room. Venetian blinds would have greater effect on the interior daylighting condition under clear sky which has both skylight and sunlight than overcast sky which has only skylight. However, due to the lack of data, design and evaluation tools, it is difficult for architects to choose or install venetian blinds during the building design stages. The purpose of this study was to develop an analysis method for shading and daylighting effects of Venetian blinds using the RADIANCE program. The major variables related to the venetian blinds included blinds's slat angle and the ratio of slat width to window height, the radius slat of curvature and the building azimuth. In this study, a series of parametric physical mock-up model measurements and genblinds command in the RADIANCE simulations. The results of this study will provide building designers with the design data at early design stages.

• 한국태양에너지학회 논문집
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• 제33권1호
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• pp.89-95
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• 2013

A DBLP(Double blind light pipe) daylight system can be installed at a building exterior wall or roof to replace artificial light during the day time. This system was consisted of a double blind light collector, a mirror duct type light transformer and a prism light pipe distributor. The double blinds were used to track the sun's altitude and azimuth movements to collect the sunlight throughout the day. The sunlight collected by the light collector was reflected on the first mirror and the second mirror and sent to the light pipe through the light transformer. The transformer was designed to deliver the sunlight into the light pipe efficiently. The light distributor plays a role in diffusing the sunlight coming in through the light collector to be used for indoor lighting. In this paper, a DBLP system has been designed, installed and tested at a KIER daylighting twin test cell. The DBLP daylighting system was applied to the experimental test cell which has an indoor area of 2.0 m wide ${\times}$ 2.4 m height ${\times}$ 3.8 m length. The experiment was conducted from January 30 to February 27, 2012, under clear skies and partially cloudy skies. Data was collected from 10:00 am to 16:00 pm every 2 minute and the average was calculated for every 30 minute of the data collection to obtain the system efficiency. The results indicated that the DBLP system efficiency was evaluated as 11.67%. The DBLP system indoor illumination energy reduction was predicted as 0.822 kWh/day. This could replace 4 sets of a 32W fluorescent lamp operating 6.4 hours per a day.

• 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.

• KIEAE Journal
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• 제9권1호
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• pp.69-76
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• 2009

The use of natural light can improve the quality of indoor environment and also occupants health. In recent years, with an increasing awareness of sustainable development, various innovative methods of integrating daylight into the building have been developed. One such device is the light pipe system. The light pipes are innovative daylighting system that allow the transmission of daylight into the hard-to-reach indoor space. The system consist of mainly three parts. First, a top collector which is mounted on the outside of the roof and gathers skylight and sunlight. Second, light-reflective tube which is coated with highly reflective mirror finish material to transmit the daylight into the diffuser. Third, a diffuser which is installed on the ceiling in the room and spread the daylight into the room. Light pipes have been widely used and researched in many countries such as Australia, America, Canada and Britain. However, despite the significant daylight potential, little work have been carried out in Korea compare to the other countries. In this study, recent lighting technology and application of light pipe system in both Korea and other countries have been compared. For the results, the benefits of each light pipe system and suitable application in Korea is also discussed.