• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.247-255
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• 2012

Daylighting has a very effective role in reducing power consumption and improving indoor environments in office buildings. Previously, it was not under consideration as a major source of renewable energy due to poor reliability in the design. Optical fiber as a transmission medium in the daylighting system demands uniform distribution of light to solve cost, heat, and efficiency issues. Therefore, this study focuses on the uniform distribution of sunlight through the fiber bundle and to the interior of the building. To this end, two efficient approaches for the fiber-based daylighting system are presented. The first approach consists of a parabolic mirror, and the second approach contains a Fresnel lens. Sunlight is captured, guided, and distributed through the concentrator, optical fibers, and lenses, respectively. At the capturing stage, uniform illumination solves the heat problem, which has critical importance in making the system cost-effective by introducing plastic optical fibers. The efficiency of the system is increased by collimated light, which helps to insert maximum light into the optical fibers. Furthermore, we find that the hybrid system of combining sunlight and light emitting diode light gives better illumination levels than that of traditional lighting systems. Simulation and experimental results have shown that the efficiency of the system is better than previous fiber-based daylighting systems.

• KIEAE Journal
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• v.7 no.5
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• pp.41-46
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• 2007

The lightshelf system, a horizontal shading and light redirect device, should improve the visual environment by optimal light distributions and intense illumination levels of a interior. This study aims to evaluate the daylighting performance of window integrated lightshelf systems by computer simulations. For the study, the standard office plan is analyzed through the field surveys. And then, the various lightshelf types attached window systems are picked out from existed research results. The max, minimum and average illuminance levels of interiors and illuminance distributions are evaluated by Lightsacpe 3.2 programs based on the installing height, shape type and moving angle of lightshelfs. As results, it is suggested that the optimum lightshelf shapes are the height 1.8m and the width 600mm. Also, in mixed lightshelf, the outside width 600mm, inside width 400 are efficient on indoor daylighting performance.

• Journal of the Korean Solar Energy Society
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• v.29 no.1
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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.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.265-273
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• 2013

The purpose of this study is to analyze the state-of-the-art daylighting design among LEED(Leadership in Energy and Environmental Design) multi-family housing cases and to explore the feasibilities for their applications in domestic housing design. Occupants in multi-family houses are reported to consume more electricity power than those in single houses. That may imply the problems of daylighting design in domestic housing design for multi-family houses have better insulation system and less windows and outside walls than single houses. Therefore two systems, daylight delivery system and daylight control system, are scrutinized for daylighting design with LEED cases. The findings show when windows as a daylight delivery system are combined with overhangs, fins, louvers, fenestration materials, speciality fenestration, or interior controls as a daylight control system, the outcome goes with more energy savings and better facade design. Beside those, lightshelves as a daylight delivery system seem to have potentials in domestic multi-family houses with deep plans and less outside walls. Daylighting designs in domestic multi-family houses need to pursue available options more to achieve the integration of energy and aesthetics values.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.136-141
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• 2009

Considerable part of energy consumption is occurred by through buildings. Especially, Lighting energy consumption is most part of one in building. There is very various ways and systems for saving lighting energy. In method, It can be divided Passive Daylighting System and Active Daylighting System. Louver, Screen and use of window's character is representative ways of passive system. Reflection mirror, optical pipe and optical fiber is representative method of active system. Introducing day light on which place can't be introduced day light by typical method is important advantage of active system. Except introducing day lighting methods, efficient lighting management system can save lighting energy. It called lighting automation system. Representatively, Occupancy-related automation and Brightness-related automation system is that. According to occupancy and introducing daylighting level properly operate lamp's intensity of illumination that can save lots of energy. Though Introducing daylighting method, effective lighting system we can get proper intensity of illuminance level and energy saving.

• KIEAE Journal
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• v.6 no.2
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• pp.67-74
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• 2006

As sustainable design technologies, advanced daylighting systems with lightshelves have been developed and are currently under monitoring the daylighting performance. This study aims to evaluate the comparative daylighting performance of sloped lightshelf and conventional glazing window with mock-up model, reconstructed as a prototype of Korean office building, sized $12.0m{\times}7.3m{\times}3.7m$ ($w{\times}d{\times}h$) and $1.8m{\times}4.8m$($w{\times}h$) for the south facing side-window was installed on the rooftop of engineering building, Kyung Hee University in Korea. It has an identical configuration of reference room and the test room. For the test room, the sloped type lightshelf system was designed as 10mm transparency sheet glass, tilt angle degree $29^{\circ}$, and total sized 1.28m (interior length 0.88m, exterior length 0.49m). It consisted of daylighting collector, entrance glazing and reflector. To assess daylighting performance, the totally 37 measuring points for illuminance and 2 view points of luminance were monitored in every 30 minutes from 12:00 to 15:00. For the detailed analysis, photometric sensors of each room were installed at work-plane (8 points), wall (7 points), ceiling (3points), and exterior horizontal illuminance (1 point). Luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio, uniformity, and luminance are discussed.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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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.

• KIEAE Journal
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• v.2 no.3
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• pp.17-24
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• 2002

For sustainable building design, using day lighting is considered a variable technique to save energy and create comfort indoor environments. Specially, the lightself as a integrated daylighting system is one of the most important techniques due to it's durability, availability and lighting performance. This paper aims to analyze the development and architectural application of a lightself system to buildings as a integrated day lighting system. For the study, advanced lightself systems developed in abroad such as "Integrated Enveloped and Lighting System", "Anidolic Daylighting System" and etc. are analyzed. Also, the architectural examples are investigated. As results, the new technologies such as optically treated reflective and sun-tracking are adopted to improve daylight performance. And, lots of environmentally friendly buildings are installed on integrated lightself system.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.93-102
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• 2021

In this research, we present a natural lighting system with transmission distance of 30m and lighting efficiency of 35% (30m standard) for operating hours of 7h/day (based on clear sky). The system is composed of parabolic reflective mirror and modified light pipe that can secure more than 88% of light concentration efficiency. The light loss rate of newly designed light pipe transmission system is demonstrated to 0.8 %/m in the straight-line part and 2%/m in the curved part. Modified light pipe daylighting system shows better performance over fiber optic daylighting system in terms of transmission distance (1.5 times longer) and illuminance (3.05 times higher).

• Korean Institute of Interior Design Journal
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• v.24 no.4
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• pp.91-98
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• 2015

Double skin façade is known that several features affected the building energy and daylighting performance. That is why the envelope is able to consist of all architectural materials such as glass, aluminum, wood and insulation for vision of residents and workers in buildings. Its specifications is very diverse according to the building designers and building owners. In recent times, visual environment became a major focus and resulted in the development of cutting edge engineering of diverse glazing systems and shading devices by growing interests of friendly environment. Thus this research has evaluated the fluctuations of interior lighting and atmospheric conditions based on double skin facade systems. Especially in terms of daylighting environment as dependent on solar variations, this research provides quantitative analysis of interior lighting conditions and how it affects the living conditions as well as improve the design of interior spaces.