• Solar Energy
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• v.17 no.4
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• pp.35-43
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• 1997

An increase in the design of commercial buildings with daylighting is beginning to receive more attention, claimed by some as a second revolution in architecture. The benefits of daylighting may vary significantly because a characteristic of daylight is the way in which it varies. Indirect sunlight, however, received in the interior of a building after reflection, can serve a useful purpose as the main source of illumination. In a cloudy climate it can serve as an occasional welcome addition to the available skylight. Also, site constraints or surrounding urban context may necessitate using reflected light sources, or such sources may be an integral part of the overall design objectives and aesthetics of the proposed projects. When reflected sunlight is introduced into a space, its role in general illumination is what is of interest in this study. Results show that reflected sunlight may help the general illumination in almost same level of significance as daylight from diffuse sky. It is also summarized that the contribution of reflected sunlight to general illumination through the year round may be even and uniform regardless of the season. Consequently, introduction of reflected sunlight should be regarded as one of the successful means to enhance the visual environment in quantitative and qualitative way.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.11a
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• pp.30-33
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• 2004

• KIEAE Journal
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• v.13 no.2
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• pp.61-66
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• 2013

This study is to eliminate the need for conventional high density plant factory's artificial light source such as LED to reduce the initial investment of the light source installation as well as the operation cost. Use of solar light could enhance the quality of the vegetables similar to those grown in the natural environment. Provision of solar light into the multilayer vegetable cultivation facilities and collecting maximum and sustainable sunlight without too much loss by tracing solar path and properly distributing it through careful control during daytime are crucial for realizing the investigated rooftop light shelf system for multi-layered vegetable cultivation. In this study, we developed an innovative way of effectively allocating sunlight inside even to otherwise shaded zone of a multi-layer vegetable cultivation facility. To prove the effectiveness of the system's sunlight collection and distribution capability, both simulation and experiment in Daejeon are performed and the outcome is analyzed.

• Journal of The Korean Digital Architecture Interior Association
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• v.5 no.2
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• pp.9-14
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• 2005

The analysis system has been needed to pre-evaluate and analyze the right for sunlight and the right for view in a residential environment since the urban high density and high rise residentinal building types have been prevailing these days. The purpose of this study is to propose an digital analysis method to evaluate sunlight and view conditions in a residential environment to improve the system performance in the sense of speed and accuracy. The digital analysis method using the object-oriented 3D CAD system and parametric library is studied and applied in the system and the various outputs of the analysis system makes possible to modify the design with the speed and accuracy as a result of the analysis. The study includes the evaluation for a daylight and view condition of each unit, and the interruption degree to a vicinity environment in terms of sunlight and view conditions comparing before and after construction.

• KIEAE Journal
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• v.17 no.3
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• pp.35-44
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• 2017

Purpose: This study questioned the efficiency of daylight factor as a daylight adequacy and investigated a method of how to complement its weakness by considering a direct sunlight component under a clear sky condition. Method: The Snowdon visitor centre cafe was chosen as a case study building and various techniques such as BRE formula, BRE sky protractor, Pilkington dot diagram and mock-upscale model under the artificial sky simulator were used to analyse and compare daylight factor values. An analysis of direct sunlight component under the clear sky condition was carried out by Climate Consultant 5.5, sun path diagram, and the artificial sky simulator. Result: The result of daylight factor analysis differed by the adopted techniques and it was also contradictory to the results on a direct sunlight penetration. The result not only showed the limitation of daylight factor as a metric but also suggested an improvement by combining it with direct sunlight analysis. The techniques used in this study had a merit of being applied in the early design stage and thus be beneficial to many design professions in order for early daylight performance analysis.

• Fashion & Textile Research Journal
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• v.3 no.3
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• pp.271-276
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• 2001

In this study, We endeavored to revaluate the effects of different types of clothing and colors on clothing microclimate in the subjects wearing sports wear at sunlight environment. This study was conducted 4 different kinds (cotton 100%) of clothing ensembles, that was W-1(long trousers and shirt of white color), B-1 (long trousers and shirt of black color), W-s (short trousers and shirt white color), B-s (short trousers and shirt black color) and were done in a climate chamber under sunlight ambient temperature ($33.67{\pm}1.8^{\circ}C$, $46.0{\pm}8.5%RH$) by three males subject who are in good healthy. Start a 20-min rest period, 20-min bouts of exercise and final 20-min recovery period were performed. The kinetic load was given for 20 minutes under the condition of 6.0 km/hr walking speed on the treadmill. The results is as followed In case of same type of garment, temperature within clothing which is based on difference of color the white ensemble keeps higher temperature than black one. According to distribution chart of temperature within clothing in case of chest, white one shows higher temperature than black one, in case of back, black one shows higher temperature than white one. Difference of heart rate was so clear and sequence is W-1>B-1>W-s>B-s, so we could find same tendency with temperature within clothing.

• Journal of The Geomorphological Association of Korea
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• v.28 no.2
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• pp.59-70
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• 2021

This study aims to determine the sunlight exposure according to depositional environment to improve the accuracy of optically simulated luminescence (OSL) dating. Sufficient sunlight exposure during transportation of sediment is a basic assumption of the OSL dating, and if the process does not occur enough, the results may be overestimated compared to the actual depositional age. Therefore, the main purpose of this study is to establish a correction method by determining residual or unbleachable dose after sunlight exposure in the actual deposition process, not in the laboratory measurement. Four samples from two sites were collected according to the depositional environment from rivers and coasts, and various OSL signals, including the size of residual dose, degree of dispersion between grains, and OSL signal sensitivity, were measured. As a result, it was confirmed that sediments formed under temporarily high energy environments, such as floods and surges, had relatively high residual dose or large dispersion of residual dose between particles. In further studies, the OSL signal characteristics of river sediments by flow velocity will be identified and the relationship between energy and OSL signal characteristics will be identified in more detail. Moreover, a method of reconstructing the paleo-environment at the time of deposition for existing sediments will be devised. It is expected to provide important information for the frequency of disaster recurrence and prediction of future climate change.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.123-126
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• 2014

This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

• Journal of the Korean housing association
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• v.14 no.6
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• pp.51-58
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• 2003

When apartment buildings are builed and re-builded, they tends to be taller. This tendency causes the problems for solar access and view in the neighboring area. So the impact factor of sunlight and view by apartment building in its neighboring area is examined. The results of this study are as follows： When analyzing sky view by dividing the sky vault into the differential area, the analysis of view can be efficient. The shorter the apartment building, the more the continuous solar access time. And the taller the building, the more the accumulated solar access time. As the height of building is taller and it is farther from the border of apartment building, view ratio, sky view ratio, and form ratio are increased. It implies that the slimmer the building, the more the visual environment can be improved.

• Advances in nano research
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• v.13 no.5
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• pp.475-485
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• 2022

Crystalline silicon photovoltaic cells have advantages of zero pollution, large scale and high reliability. A major challenge is that sunlight wavelength with photon energy lower than semiconductor band gap is converted into heat and increase its temperature and reduce its conversion efficiency. Traditional cooling PV method is using water flowing below the modules to cool down PV temperature. In this paper, the idea is proposed to reduce the temperature of the module and improve the energy conversion efficiency of the module through the modulation of the solar spectrum. A spectrally selective nanofilm reflector located directly on the surface of PV is designed, which can reflect sunlight wavelength with low photon energy, and even enhance absorption of sunlight wavelength with high photon energy. The results indicate that nanofilm reflector can reduce spectral reflectivity integral from 9.0% to 6.93% in 400~1100 nm wavelength range, and improve spectral reflectivity integral from 23.1% to 78.34% in long wavelength range. The nanofilm reflector can reduce temperature of PV by 4.51℃ and relatively improved energy conversion efficiency of PV by 1.25% when solar irradiance is 1000 W/m². Furthermore, the nanofilm reflector is insensitive in sunlight's angle and polarization state, and be suitable for high irradiance environment.