• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.78-86
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• 2008

The aim of this paper is to show the daylight environment of a light pipe system according to sun movement. A light pipe system has been mounted on the roof of the windowless full scale model: the solar spot has diameter of 0.65m and is 1.3m long, giving an aspect ratio of 1:2. The full scale model was installed on the rooftop of the SHINAN apartment in Yongin city that has no obstructions against sunlight. The test room is equipped with sensors for the measurements of the internal illuminance and has an area of 6m(W)$\times$6m(D)$\times$4m(H). The system has been monitored with a data-logger to evaluate the cumulative distribution of illuminance on a floor-plane from 16th, April to 29th, May, 2008 over one month and selected clear sky condition. For the daylight performance of floor area, the totally 49 measuring points has been used to determine the internal illuminance and an HP datalogger(HP34970A) records the measurements for one consecutive month. The horizontal external illuminance has been measured with two outdoor sensors. This paper presents the results of monitoring light pipe system with internal/external illuminance ratio and cumulative frequency distribution of floor-plane illuminance are discussed The results show that lightpipe is proficient device for introducing daylight into the building. However It provided different daylight indoor environment with wide or narrow Interquatile range of illuminance, internal/external illuminance ratio and cumulative frequency distribution according to solar positions under suuny sky condition. For more achieving the improvement of lightpipes also include energy savings, user visual comfort with various indicators; seasonal solar height, room and lightpipes geometries.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.23-34
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• 2004

In this study, 1 dependent variable and 9 independent variables were established to examine suitable illuminance by spaces in urban parks in consideration of night users' psychological reactions and activity types. Such fixed variables were evaluated by a series of experiments of changing illuminance, and correlation among those variables was verified by correlation analysis and multiple regression analysis to suggest suitable illuminance by spaces. The results of this study are as follows: 1) The independent variables influencing suitable illuminance by spaces in urban parks were directly influenced rather by the psychological reaction of night users than the activity types by spatial functions. 2) Securing suitable illuminance by spaces commonly increased spatial availability, created certain atmosphere, and provided safety in the psychological reaction of night users. 3) Suitable illuminance by spaces in urban parks is: Central square is 31.88lx, resting space 6.30lx, exercising space 33.14lx, children's playground 14.19lx, pedestrian road 12.29lx, entry space 16.30lx, and green space 7.03lx. That is, when a place had more positive activities, spatial illuminance was increased. 4) Though comparison by spaces with the illuminance standard for urban parks as mentioned in KS A 3011-1993 can not be made, such illuminance was relatively compatible with the permissible range of illuminance in the author's opinion. It is expected that this study investigating suitable illuminance by spaces for night use in urban parks, will provide necessary knowledge for securing suitable illuminance by spaces in urban parks through classifyingin detail the illuminance standard of KS A 3011-1993. Besides, by helping make us aware of the importance of illuminance in urban parks as well as of external space in the night, this study will contribute to academic research and development in the field of landscape architecture and associated fields and be utilized in establishing legal and institutional standards.

• Journal of the Korean Institute of Educational Facilities
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• v.15 no.2
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• pp.4-15
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• 2008

The purpose of this study was to evaluate the characteristics of daylighting environment in classroom of an school building due to the external shading devices such as fixed louvers, light shelves and exterior venetian blinds. In this study, we have made a field research with regard to the facade design in classroom of an school building. And we have made a classification of external shading devices considering the design parameters. Finally, through RADIANCE simulation, we have calculated the spatial distribution of illuminance, uniformity ratio of illuminance and daylight factors. The results of this study will provide the building designer with the basic daylighting performance data at early design stages.

• KIEAE Journal
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• v.8 no.1
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• pp.53-60
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• 2008

The daylighting affects on the human biological cycles and physiological alterations. Daylighting is also an important element in visual comfort and it sometimes influences the quality of vision. Therefore the absence of natural light during the day brings contradictory result. To solve the problems of natural light lack and provide sufficient daylight in interior spaces, it might be necessary to apply some daylighting systems. One of these systems, light pipe system, which is simple, cheep and easily constructed, is very useful to apply for small buildings. The light pipe is simple means of directing daylighting (diffuse and direct lighting)into interior space. In order to application of light pipe system in Korea, it is necessary to optical data of light pipe system. This study aims to evaluate preliminary experiment of the daylighting environment of light pipe system. Light pipe system, that aspect ratio is 1:2(diameter and length), was installed in a windowless mock-up with $27m^2$. The mock-up model was constructed as a prototype of Korean office surface. Illuminance was measured with a Topcon IM-5 Luxmeter to evaluate the distribution of the illuminance on a floor. The indoor and outdoor illuminance and the internal/external illuminance ratio are compared to discuss with in the graphs. Luminance was measured with Radiant imaging Promertric 1400 that is digital photometer to evaluate the distribution of luminance on interior surface. The contrast of luminance is discussed with table and graphs.

• Architectural research
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• v.7 no.2
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• pp.47-54
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• 2005

A photoelectric dimming control system for a small private office space with a double skin envelope system was analyzed for the purpose of examining optimum control performances under a variety of daylight conditions. Computer simulations were performed for the three different photosensor types positioned at the center of ceiling in the space. They were applied in both a south and north-facing room. Daylight conditions were a fixed horizontal venetian blind on an external envelope and a retractable shading device on an internal envelope under a clear, intermediate and overcast sky at different times of a day and year. Partially-shielded photosensors provided good control performances providing the required electric light output under clear and intermediate sky conditions. Unshielded photosensors failed to provide necessary illuminance levels producing less electric output and fully-shielded photosensors generally provided excessive light output. Reasonable electric lighting energy savings were achieved except under overcast sky conditions where the control system did not contribute to energy savings due to the less daylight through envelopes. The retractable shading device covering 50% of the internal envelope reduced energy savings up to 19.62%, but the workplane illuminance levels were maintained within recommended ranges. The coefficients of determination between workplane illuminance and photosensor illuminance due to daylight ranged from 0.74 to 0.98. Partially-shielded conditions provided best correlations and the north-facing room yielded stronger correlation than the south-facing room.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.117-128
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• 2014

As the main cause of car accidents is driver distraction, HUD utilization is important to boost drivers' front-observing. Recently, As HUD includes a variety of contents products have appeared on market, the possibility increases cognitive load while driving. The purpose of this study is that currently being used HUD contents how much affect drivers while driving. To investigate about it, the experiment is examined cognitive aspect with utilization aspect of different gender and illuminance environment. The study provides, in accordance with the internal and external illuminance, the visibility make a difference. The gap between the internal and external illuminance is higher, the visibility is better. Also, this study confirms that HUD's awareness of contents depends on driving information. Drivers concentrate more on higher related driving contents than lower ones.

• KIEAE Journal
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• v.12 no.1
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• pp.35-43
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• 2012

Algorithm-based architecture helps specifically dividing the environmental variables of a target space into individual factors to build object-oriented programming, classifying them into an individual object according to the environmental variables of each planning circumstance, and distributing each structure into small structures. In addition, each itemized matter of construction is set as a condition, and thus it is possible to respond to the space condition of various circumstances which occur in the architectural planning process. This study is intended for predicting that a sketch role in the design process can be replaced by a design method utilizing an algorithm, through the external solar radiation and the illuminance value of indoor lighting device among the environmental variables of a target space, and for seeking a way to create a design alternative and improve the design quality by using computer-based algorithm design.

• New & Renewable Energy
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• v.19 no.3
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• pp.13-21
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• 2023

Smart windows are capable of varying their visible light transmittance (VLT) in response to changing environmental conditions. The VLT variability of architectural windows is highly valuable because it enables indoor lighting and energy environments to align with external changes. However, challenges such as high installation costs and assurance of glass visibility have prompted the exploration of alternative solutions, including models incorporating partially applied smart windows., Prior research focused on useful daylight illuminance (UDI) analysis for south-facing office buildings, pointing out suitable areas for smart-window implementation to enhance lighting control. In this study, we broadened this scope by determining optimal smart-window application zones under changing building orientation. Furthermore, we studied the correlation between building orientation and smart-window deployment areas.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.129-135
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• 2015

The Ubiquitous City (U-City) spatial information technology aimed to provide services freely anytime and anywhere by converging high-tech information & communication technology in urban infrastructure has been available in diverse patterns. In particular, there have been studies on the development of 3D spatial information after selecting and matching key points with stereo images from the many Closed Circuit TV (CCTV) in the U-City. However, the data mostly used in extracting matching points haven't considered external environmental impacts such as illuminance. This study tested how much the matching points needed to construct 3D spatial information with the CCTV whose image quality is dependent upon changes in illuminance fluctuate under the same hardware performances. According to analysis on the number of matching points by illuminance, the number of matching points increased up to 3,000Lux in proportion to the illuminance when IRIS, shutter speed and ISO were fixed. In addition, a border between an object and background became more distinctive. When there was too much light, however, the page became brighter, and noise occurred. Furthermore, it was difficult to name key points because of the collapse of an inter-object border. It appears that if filmed with the study results, the number of matching points would increase.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.14-19
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• 2013

Tunnel lighting design and operation are both regulated based on luminance in and out of Korea these days. However, domestic tunnel lighting is operated by internal lighting depending on external brightness by using an illuminometer applying the conversion factor on luminance. The purpose of tunnel lighting is to alleviate the visual shock occurring from the rapid change from external brightness to internal brightness when entering a tunnel. However, when looking at the tunnels operated based on an illuminometer, it is not a system where the driver can measure the brightness within his or her viewing angle when entering the tunnel. It is general to install and operate the illuminometer on the roof of an administrative office near the tunnel; however, this method is not structured to connect with the internal lighting by checking the brightness of the viewing scope of the driver, thus is not structured to properly apply the viewing conditions of the driver. Rather, it should be in a method for extracting the luminance value within the viewing scope of the driver pursuant to tunnel lighting standards and in connection with internal lighting. This research seeks to find the difference between operations based on luminance and operations based on intensity of Illuminance in road tunnels through field measuring, and to suggest the necessity of operating based on luminance with the resulting value.