• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.73-80
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• 2003

The purpose of this study was to analyze daylighting performance in a semi-infinite size office space for lighting energy conservation. DOE2.1E was used for simulations for the model space of $12\times12\times2.6m$. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption rate and energy reduction rate for daylighting design. Major results of simulations are as follows ; 1) When blinds facing south were installed, 43% of workplane illuminance diminished, but the flare index didn't exceed the recommended max-glare value. 2) In a semi-infinite office space facing south. energy consumption rate in the case space of 500 lux workplane illuminance is larger then case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the semi-infinite office faces south and naintains 300 lux workplane illuminance level.

• Korean Institute of Interior Design Journal
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• v.13 no.2
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• pp.176-183
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• 2004

This research is aimed at being a cornerstone to elicit the evaluation methodology of systematic and objective lighting design process on the basis of investigation of documentation and interviews on lighting design of architecture which is drawing more and more attention in an architectural field. In evaluating lighting design in architecture, such factors as appropriate illumination, quality of light, completion degree, reflection of use, visual amenity, understanding, amiability, artistic value, recognition, regional conditions, and extent of glare are to be more considered than anything else. In so far as general sectors of society show ever-increasing interest in lighting design, developments in both its quality and its quantity are also expected; thus, evaluation items shown in this research will be useful in appraisal of interior and exterior lighting of architecture.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.76-81
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• 2013

In our former study, we proposed that the AC-Model might be applied to various conditions. And we also introduced the method for daylighting that it was possible to reduce discomfort glare and to improve visual impressions as the supplementary type and blind-control type on the compound lighting. The purpose of this study was to examine the relationship between physical elements and psychological evaluation of lighting space. The study was made using an full-size space, which were equipped with various luminaries. We investigated the relationship between subjective evaluation and characteristics of light distribution and showed the high correlation between the evaluation rating and luminance distribution over whole room.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.9
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• pp.1-9
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• 2015

The aim of this study is to deduce color temperature and illuminance by conducting the preference & affective evaluation consequent on illuminance change of ambient light in case of the lighting method of ambient light mixed with task light in time of reading which is visual work action among the action in learning space. As a result of the prior survey on preferred lighting method in time of the act of reading targeting 20 experts before doing evaluation, the method of lighting mixed with ambient light and task light was found to be the highest. Such a result is analyzed to be attributable to the fact that the less the difference in illuminance of nearby space and work surface because of the mixed method of lighting, the less the glare, which makes a reader feels easy and concentrate on reading. On the basis of descriptive statistics of evaluation results and impact analysis by category, this study recommends the application of combinations of ambient light illuminance ranging from 40lx to 100lx with color temperature of 5500~6000K in case of the method of lighting mixed with general light and task light.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.115-125
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• 2003

The concrete median barriers are the most popular safety appurtenance that can be installed on narrow medians and are effective in keeping uncontrolled vehicles from crossing into opposing lanes of traffic. It is necessary to install and maintain median barriers because it is very difficult to reserve enough room required for medians in KOREA. Also, concrete median barriers are accepted as the actual alternatives for median barriers, mostly because they require almost no maintenance even after serious collisions. Typical concrete median barriers are 810mm high and have 596mm high glare screens on top of them. However we have experienced a number of "climb" and "roll-over" accidents of heavy vehicles and most of all, there have been some serious accidents caused by the part of broken glare screens. So the improvement study of concrete median barriers started. Prior to this study, a new type of concrete median barrier was suggested which is 1,270mm high and has no glare screens on top of it. So it was required to compare the properties of various types of concrete median barriers including the new type to find the optimal type of concrete median barrier. In this study, we have evaluated the characteristics of four types of concrete median barriers (New Jersey type, F type, constant slope type, and wall type). We have performed many computer simulations for the evaluation of the crashworthiness of them, and through the simulations we have tried to find a proper type of concrete median barrier. Through the computer simulations, we evaluated the structural stability and safety of the four types of concrete median barriers. We confirmed the structural stability and safety of them But in regard to the probability of "roll-over" of heavy vehicles, the higher concrete median barriers showed better performances than the lower. As the result of this study a new type of concrete median barrier was recommended.

• KIEAE Journal
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• v.14 no.1
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• pp.15-22
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• 2014

Among the various building envelope elements, the glass area takes up the largest portion in the office building design. However, a large area of glass can cause problems such as excessive solar radiation, thermal comfort, and glare. Thus it is important to install the glass area to an appropriate level, and control solar radiation and inflow of daylight with blind devices. This study aims to improve the visual performance of the work plane through the automatic control of the venetian blinds. A total of eight kinds of control strategies were chosen; Case 1 does not control the blinds, Case 2 with the blind slats fixed at the angle of 0 degree, Case 3 to 6 using the existing blind control programs, and Case 7 and 8 with improved blind control. Case 3 with 90 degrees had the best energy performance, but the average indoor illuminance was 113lux, which is below the standards. Cases 4 and 5 showed higher levels of interior daylight illuminance with the average of 281lux and 403lux respectively. However, the fixed angles may have difficulties controlling excessive direct sunlight coming into the room and may cause glare. Cases 6 and 7 used sun tracking angle control and cut-off angle control, and the average interior illuminance was measured 250lux and 385lux respectively. Case 8 used the cut-off angle control in an hourly manner, satisfying the standard illuminance of 400lux with an average interior illuminance of 561lux. It was evaluated to be the best method to control direct solar radiation and to guarantee proper level of interior illumination.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.7-12
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• 2008

Purpose: To evaluate ultraviolet (UV) blocking characteristics of transparent and tinted ophthalmic lenses. Methods: The transmittance spectra of ophthalmic lenses were measured using the method suggested in ANSI Z80.1 standard. Transmittance percentage were calculated for each lens for UV (200~380 nm; UVA, UVB, UVC) and blue light portions (380~400 nm) of spectrum. Results: The results indicate that transparent plastic lenses with middle, high refractive index and tinted plastic lenses had superior UV blocking characteristics at UV radiation while UV blocker-untreated lenses such as crown glasses and CR39 did not. All except high refractive index lenses and anti-glare night vision lens was not effectively blocked blue light. Conclusions: Crown glass and CR39 lenses need to treat UV blockers to protect eyes from UV. Also, all lenes except high refractive index lenses and anti-glare night vision lens need to treat blue light blockers for protecting from blue light.

• Journal of radiological science and technology
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• v.31 no.1
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• pp.55-60
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• 2008

Purpose: This study is to decide a quality control and calibration period of LCD display devices used for reading diagnostic images. Materias and Methods: The assessment test of 20 flat panel LCD color display devices used for reading diagnostic images were performed based on AAPM TG 18 protocol over the total six sessions at one month intervals from three months after primary calibration, in terms of geometric distortion, reflection test, luminance response evaluation, luminance uniformity, resolution, noise, veiling glare and chromaticity test. Results: The results of geometric distortion, reflection test, luminance uniformity, resolution, noise, veiling glare and chromaticity test were within the criteria recommended by AAPM TG 18, except for luminance response evaluation. In the measured luminance deviation of luminance response evaluation, 4(25%) of 20 display devices were passed a criterion from four months after calibration, and 11 (55%) were passed from eight months. Also in the contrast response of the luminance response evaluation, 1(5%) display device was passed a criterion from four months after calibration, and 3(15%) were passed from eight months. Conclusion: Considering the passing deviation after calibration, the time required and a manpower, the quality control and calibration period of LCD display devices used for reading diagnostic images should be a three months and six months after calibration.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.125-130
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• 2007

The aim of this study is to discover the possibility as the shading systems, and to analyze daylight distribution and characteristic of light on the Korean traditional paper. Korean traditional paper has a good efficiency to diffuse the light and is less glare than Roller Shade fabric. In the president office buildings and apartment houses, daylight characteristic of Korean traditional paper windows could be used as a preliminary data to develop a window system which makes greatest performance of daylight.

• KIEAE Journal
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• v.10 no.4
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• pp.3-8
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• 2010

Recently, various daylight evaluation methods for visual environment have been developed; simulation analysis methods, numerical calculation, and data monitoring methods. However, it is impossible for simulation analysis to make real scenes and visualize real images exactly. Also, a numerical calculation is considered as an out of date and time-consuming mean. Therefore, for acquisition of accurate results, many studies often use the monitoring data methods. Especially, most studies regarding discomfort glare are evaluated by measuring the physical quantity of luminance through traditional measuring Minolta Luminance meters as an instrument. But, this method has a difficulty in measuring several points at the same time because of the limitation of spaces and time when mapping. So, this study focused on the potential usefulness of High Dynamic Range photography technique as a luminance mapping tool. In order to evaluate the accuracy of proposed programs such as webHDR, Photomatix and PHOTOLUX, this paper has conducted an experiment by using Canon EOS 5D and NICON Coolpix8400 digital camera.