• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.55-64
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• 2010

The study has conducted a research on the main shape of domestic multi-family residential buildings. The four arrangements were selected after the research and each of them was analyzed for daylight, view and natural ventilation according to the different pitch of buildings. Based on the results from the analysis, the optimum pitch of buildings for each of the arrangements are as follows. With looking at the outcomes from the analysis on changes in residential environment by the pitch of building buildings in the four arrangements, it was figured out that it would be the best if the distance is more than 1.0H for Case_1. For Case_2, it should be more than 0.9H and for Case_3, it has to be 1.0H or more. Last but not least, it seems to be superb if the distance is more than 0.9H for Case_4.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.433-442
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• 2012

The influence of outdoor sky conditions on photosensor signals were examined to determine an appropriate index that is effectively used for optimum illuminance fluctuation when a daylight dimming system is used for a small office. Field measurements were conducted under various sky conditions. Results indicate that the outdoor global and vertical illuminance fluctuated within narrow ranges under clear and overcast sky conditions. The fluctuation of sky ratio under partly-cloudy sky caused wide ranges of illumnance fluctuation. A partially-shielded photosensor at backwall produced 56% of light output from fixtures controlled by a photosensor at ceiling. This implies that the photosensor at backwall does not always guarantee target illuminance due to the less output. The fluctuation of light output from fixtures were insignificant under clear and overcast sky. The fluctuation range of photosensor illuminance under partly-cloudy sky caused wide fluctuation ranges of light output. Regression result implies that the outdoor vertical illuminance was recommended for an effective index that is used for control of light output.

• Journal of Power System Engineering
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• v.20 no.1
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• pp.63-68
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• 2016

The study is arranged in the form of plate-shaped in the Apartment Houses with placed at right angles. After examined the daylight environment and the indoor illumination in this form of Apartment Houses, in order to improve the daylight environment of the lower floors, I examined the daylight environment. In order to match the indoor illumination, as a standard illumination 400lx, I examine the necessary lighting energy based on the direction and time for the different parts in the Apartment Houses, As the first floor, the lowest power requirement appeared to the South(457W), and the most power requirement appeared to the East(843W).

• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.513-517
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• 2007

To elucidate possible challenges for outdoor practical use of dye-sensitized solar cells (DSCs), we compared conventional Si solar cells with DSCs. DSC modules still require a larger area than conventional Si solar modules to attain the same rated output because of lower photoelectron-chemical conversion efficiency. However, in backup systems by using batteries, the measured data shows that DSCs generated 15% more electricity than Si solar cells of the same rated output power in the same interval of cloudy daylight. Moreover, the battery charging time of DSCs is about 1 hour faster than the same rate of Si solar cells under outdoor cloudy daylight. This result also indicates that conversion efficiency obtained by the certified condition less than AM 1.5 condition does not always coincide with the electricity generated outdoors daily, and it is not a crucial measure to evaluate the performance of solar cells.

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.245-252
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• 2010

Korea Astronomy and Space Science Institute (KASI) has developed a mobile satellite laser ranging (SLR) system called ARGO-M since 2008 for space geodesy research and precise orbit determination technologies using SLR with mm level accuracy. ARGO-M is capable of night tracking and daylight tracking for which requires spatial, spectral and time filters due to high background noises. In this study, characteristics and specifications of ARGO-M are discussed and its tracking capabilities of night and daylight tracking are analyzed for STSAT-2B and KOMPSAT-5 through link budget. Additionally false alarm and signal detection probabilities are also analyzed depending on spectral and time filters for daylight tracking for these satellites.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.74-86
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• 2012

For the improvement of environmental comfort in the buildings with the blind control, the objective of this study is to prevent the direct glare caused by the daylight inlet. During the process of solar profile prediction, time are significant factors that may cause error and glare during the blind control. This research proposes and evaluates the correction and control method to minimize prediction error. For the local areas with different longitude and local standard meridian, error occurred in the process of the time conversion from local standard time to apparent solar time. In order to correct error in time conversion, apparent solar time should be recalculated after adjusting the day of year and the equation of time. To solve the problems by the potential time errors, control method is suggested to divide the control sections using the calibrated fitting-curve and this method is verified through simulations. The proposed correction and control method, which considered potential time errors by loop lop leap years, could solve the problems about direct glare caused by daylight inlet on the work-plane according to the prediction errors of solar profile. And also these methods could maximize daylight inlet and solar heat gain, because the blocked area on windows could be minimized.

• KIEAE Journal
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• v.10 no.2
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• pp.25-30
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• 2010

The daylited space can improve visual comfort and occupant's well-being. However discomfort glare from the daylight is a common problem in indoor environments and in general, the window is the main glare sources. Some formulas have been proposed for predicting glare from the daylight, however, they do not consider the effect on glare of the view through a window and some studies proved that they are inadequate in real daylight situation. This research aims to identify the relationship between view and discomfort glare considering the subjective impressions. As a preliminary experiment, this paper sets up the experimental protocol to reveal relationships between views from a window and visual perception in a controlled laboratory experiment. $1.2m{\times}1.2m$ artificial window was developed and $0.9m{\times}0.9m$ view image was placed on the window. Discomfort glare and impression evaluation was carried out under four different views and one blank view as a reference condition. The results showed that the subjects evaluated discomfort glare differently with the views even under the same luminance conditions and tended to feel less glare with distance views compared to near views.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.15-21
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• 2003

This paper presents field measurements on daylighting and electric lighting with dimming controlled systems for a small office in Seoul, Korea. And the main purpose of this study is to provide the evaluation data of lighting energy performance when a dimming system is installed. For the performance evaluation, the mock-up room(3.6x7.2x2.6[m]) was used for the actual test. The results of this study were as follows; 1) The correlation between daylight illuminance at a workplane(Ed) and the photosensor signal(Sd) was an important factor affecting the performance of daylight responsive dimming system, 2) The mock-up office space gained a sufficient workplace illuminance of 579[lux] with the dimming control system 3) About 53[%J of monthly lighting energy could be saved using the dimming control system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.7
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• pp.491-499
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• 2007

An architectural means of optimal daylight distribution is by using so-called light shelf systems, horizontal shading and redirecting devices. The overall performance of the daylighting system can be improved by the incorporation with electric lighting control devices. This paper aims to exemplify the benefit of daylighting in term of economic consideration. In such a case a reasonable technique to compare system costs is by life-cycle costing. Stated simply, a life-cycle cost represents the total cost of a system over its entire life cycle, that is, the sum of first cost and all future costs. Four different electric lighting system designs are proposed and a lighting control system that is continuously operating according to the level of daylight in the space has been adapted. The result shows clearly that although denser layout of lighting fixtures might be more effective to interface to the level of daylight ceaselessly changeable, its economic benefit may not meet the expected criterion the reason of increased initial investment and maintenance cost for the fixtures and control devices.

• Journal of the Korean housing association
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• v.4 no.2
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• pp.1-9
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• 1993

This study is a basic research to analyze and estimate the light environment of the classroom by serial correlation of time. Its purpose lies in the comparison by time period in order In select floor for laboratory and to calculate the uniformity factor. The proving ground is T building in W university, Which is five floor of central hall type. The subject of investigating is eight classrooms, four rooms in South and North, from the second floor that is net influenced by the shelter. The results that compared and estimated them in the illumination of daylight, Uniformity factor, Daylight factor, are as follows1. The illumination of classroom in South and North is over 10001x, but the classroom in North is good and the classroom in South excellent.2. The uniformity factor of classroom in South is good and that of classroom in North is normal.3. The daylight factor of each classroom is over 5% but the classroom in South is above that in North. The classroom in South surpasses the classroom in North in the general light environment and the classroom in third and fourth floor is so better than that in second and fifth floor in the condition of laboratory In the uniformity factor, the classroom in fourth can be better than any classroom.