• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.788-797
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• 2010

This study examines the influence of fluctuating daylight illuminance on daylight dimming control systems. Field measurements were performed for a full-scale mocked-up model under various daylight conditions in winter. Fluctuating ranges for a partially-shielded photosensor were great when the variation of sky ratio was great. When solar altitude was lower the illuminance and fluctuating range of illuminance were great due to the influence of direct components of daylight and the interrefelction between surfaces in rear area of space. It implies that daylight dimming system would not function effectively, unless the desktop illuminance by daylight is enough. Fluctuation ranges of photosensor illuminance were lower than 50 lx under clear sky conditions, but they were greater than 100 lx under partly-cloudy sky conditions. It means that the fluctuation range of electric light output of lighting fixture would greater under the partly-cloudy conditions and cause potential visual annoyance to occupants. Outdoor vertical illuminance reaching the windows would be an effective factor that can be used to predict the fluctuation of photosensor signals for effective controls of daylight dimming system.

• Journal of the Korean Solar Energy Society
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• v.22 no.4
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• pp.26-34
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• 2002

Daylighting in building is very important as it has an effect on work performance as well as on their visual health. It is also regarded as a good energy conservation measure in saving energy used for lighting. There are many daylighting evaluation tools such as empirical equations, tables, nomograms, diagrams, protractors, computer simulation, scale models. This study conducted initial daylight measurements to analyze luminous environment in classrooms of elementary school and comparative analysis on three daylighting evaluation tools, such as daylight factor calculation formula, the graphic method with BRE Protractor and computer simulation with Adeline 3.0. It is found that the computer simulation tool produced the closest result to actual measurements of luminous environment in elementary school classroom, and the other simplified tools made appropriate results so that they can be used in the early stage of daylighting design process.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.97-100
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• 2008

The daylight responsive dimming system is an energy saving system that automatically controls lighting output of artificial lighting according to available daylight in inside, as well as keeps uniform workplace illuminance. The basic three components of the daylight responsive dimming system consist of a photosensor, a controller and a dimming ballast. This paper is a fundamental study of photosensor modeling for the daylight responsive dimming system. The correlation between photosensor illuminance on the ceiling and workplace illuminance is an important factor to accuracy of system performance, so that the purpose of this study is to improve accuracy for daylight responsive dimming system. This study performs to derive the optimized conditions of photosensor using the RADIANCE.

• KIEAE Journal
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• v.13 no.6
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• pp.77-82
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• 2013

Light environment in the school building is one of the most important elements of the plan in order to improve student's ability to learn and the healthy growth. Thus, the window plan of the school building is a great addition to improve environmental-friendly performance through the daylight control. Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the school building design process, because of lack of previous studies on the light environment of student and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. ECOTECT simulation were performed using weather data. As a result, ECOTECT simulation are performed for daylight autonomy and useful daylight illuminance. Using this data, Window planing is to propose and effective method in the early stages of design.

• KIEAE Journal
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• v.13 no.4
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• pp.3-10
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• 2013

This study aims to identify convenient surrounding of the hospital room to be improved by specifically focusing on light environment and to examine a change of inflow of the daylight in the hospital room by using blind and light shelf device as base data of preliminary research for comprehending the relationship between healing environment and natural day light. Simulation analysis on previous facilities and the installation of horizontal light shelf that derives the inflow of day light has been specifically referred by using ECOTECT2011 program. In case of C-facility that mostly adjoined to exterior spaces, it was shown to be closer to a proper uniformity factor when an angle was controlled on the light shelf with blind installed at the same time. However, it was not overall appropriate because of visual displeasure occurred from inflow of much day light. In conclusion, it is the form of flat surface such as H-facility that provides an effect after installing the device to derive day light. Especially, it was shown that interior day light environment was improved when installing blind and controlling the angle at the same time.

• KIEAE Journal
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• v.11 no.6
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• pp.71-79
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• 2011

There are high recognitions on the importance of comforts in Elderly living environment, but the circumstance is that studies on seniors facility space itself are approached only in planning level, and studies on lighting environment which is significantly associated with the comfort in the indoor environment of seniors where they actually spend the majority of their time are not that active. This study was intended to deduce cozy bedroom environment to which existing elderly care facility can be improved by using light shelf the lighting system with the advantage of being able to serve both as building sun visor and lighting window simultaneously in order to analyze the interior environment of bedroom space of elderly care facility the indoor space where the aged spend the majority of their life and examine the directions for the improvement of existing building lighting system through remodeling and renovation. In this study, lighting performance analysis was done in a way that the windows of the bedroom unit in existing facility were set in southbound direction based on two standard types and were put under initial simulation with the use of Autodesk Revit 2011, and after the simulation results were converted to Green Building Studio gbXML file to be used in ECOTECT, Daylight Autonomy a dynamic simulation and static natural lighting simulation the existing method of calculating daylight factors were deduced through Ecotect Analysis 2011. In conclusion, exiting standard model was found in such a condition that the daylight factors for both type A and type B were above 5% the proper standard value, and required improvement. In case light shelf the natural lighting system was attached, the daylight factor was improved to proper standard value for type A, and also was improved above existing facility for type B.

• 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.

• Journal of the Korean Solar Energy Society
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• v.34 no.5
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• pp.1-9
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• 2014

Daylight is very useful to control the indoor environment, and can save energy in buildings. So it is necessary to evaluate the daylighting performance of buildings. We proposed a simplified equation that can be used in the early stages of design. And we verified the equation by using the measured illuminance data from the 1/5 scale model. We compared the calculated indoor illuminances and measured illuminance including Daylight Factors of scale model in order to verify the applicability of the simplified equation, and proved the analyzed values are acceptable. When we have a target value of the Daylight Factor, we just have to determine the window area, transmittance of the glazing system, and indoor surface reflectance, then can achieve it with this simplified equation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.58-62
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• 2017

In this study, the design conditions for the Korean-style glass greenhouse structure has been reduced to achieve the most efficient use of natural light. The AGI program was simulated for the optimal conditions of daylight in a glass greenhouse. From the results of daylight simulation, the axis position of the glass greenhouse's roof was not an important factor in the daylight effects regarding illumination and uniformity. In summer, there were long periods of daylight and high illumination levels. The illumination value of daylighting increased with increasing glass transparency value, and the illumination value was greatest at 14:00 hours. At this time, the rate of light variation according to the glass transparency was 89 [lux/%]. In addition, the optimal design conditions for the glass greenhouse were established, which were a $30[^{\circ}]$ or $150[^{\circ}]$ installation angle and higher transmittance of glass.

• Journal of the Korean Institute of Educational Facilities
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• v.9 no.5
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• pp.13-21
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• 2002

Daylighting in educational environment is very important as it has an effect on students' performance as well as in their visual health. It is regarded as a good energy conservation method in saving energy used for lighting. This study conducted initial daylight measurements to analyze luminous environment in classrooms of Korean elementary school. The results indicated that the typical classroom had a reasonable level of daylight. However, it also found that the classroom had some problems of the uniformity of illuminance and the contrast of brightness of surfaces in the classroom. It is argued that daylighting design for school classroom should consider these aspects to make daylit classrooms ideal so as to provide comfortable visual environment.