• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8901-8907
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• 2015

Conventional streetlight with the not-adjustable light distribution characteristic is generating light pollution such as glare, damage to the crops and disturbed sleep, because beam of streetlight is not distributed evenly according to the surrounding areas and road conditions. In this paper, we proposed the new structure LED streetlight controlled light irradiation angle according to the surrounding areas and road conditions. Proposed LED streetlight are available to the adjustable light distribution characteristic using the half-circle angle control device. Result of measurement and simulation, beam angle is made available to control at least from $100^{\circ}$ up to $154^{\circ}$, average illumination exceeded 15% of KS regulation and overall uniformity exceeded more than 50% of KS regulation. the Developed large capacity LED streetlight luminaire is considered to minimize glare and light pollution and optimize uniformity ratio of illuminance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.42-48
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• 1996

Glare phenomenon by sun's altitude and strong sunlight make a much visual handicap. And so, it reaches to unreadable situation although enough illumination in the fore site student of a window site and passage site. In school student seat arrange in the order of their height. So, cause the eyesight acuity according to distance is different, eyesight of backseat's student drop 1.0 and less in spite of 1.0, a learning effect reduces rather then that of the fore site student for site and Passage sitestudents. Therefore. in school, the conclusion's alteration of school structure, position's alteration and material quality's improvement of blackboard are needed, should be local lighting in blackboard. Therefore, we think that in other in improve the effect of lesson by the student, the student seats are not given by uniform disposition in the order of their height but change by a specified period.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.1-8
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• 2004

Nowadays the soccer becomes one of the best spot lighting sports in the world Especially the 2002 Korea-Japan World Cup was deeply impressed on all the korean. One goal of illuminating engineering should be the design of lighting system that can provide consistently high task visibility regardless of where a task might be located within a working space. The television broadcasting on the soccer has been an important role in the media. The standard of FIFA(The Federation Internationale do Football Association) requires recommended illuminance levels for artificial lighting for a player, an audience, TV broadcasting, as well as everybody in the stadium. This paper has proposed an algerian to select the suboptimal lighting tower position for watching and TV broadcasting a soccer game within a pleasant environment and an optimum illuminance distribution. The position using the software Philip's Calculux was chosen based an the calculations of a horizontal illuminance, vertical illuminance, uniformity, glare, and so on by changing lighting tower positions.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.73-81
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• 2000

This review on ocular toxicology concentrates on the effects on ocular health and contact lens wear induced by systemically used drugs, including alcohol. Many systemically administered drugs produce ocular adverse effects. Fortunately, relatively few are capable of causing significant, irreversible visual impairment. The visual symptoms of acute intoxication are as follows : Drop in vision/visual acuity, diplopia, poor dark adaptation, increase in time for glare recovery, early cataract, decreased depth perception, blue-yellow or red-green colour defect and visual hallucinations. Blinking pattern, tear production, and discoloration of contact lenses can be affected by some systemic or local ocular medications. The cornea, conjunctiva, or eyelids may react to some systemic medications and to some preservatives used in contact lens solutions. The hydrogel contact lens act as a drug reservoir that emits the drug over time. I discuss management of contact lens-induced infectious and inflammatory conditions.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.618-627
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• 2007

As our society progresses rapidly toward an aged society, there is a stiff increase in the population of the aged persons who have difficulties in adjusting themselves to environments due to declines of their physical functions. Therefore, there is a great need for the concept of 'Universal Design' that demands the design of overall social structure to care for the elderly. Due to this reason, the physical function of the aged persons should thoroughly be studied for the development of rehabilitation and training equipments to help the recovery of physical functions of the elderly. Among the variety of physical functions of the elderly, visual functions, motion characteristics, hearing functions, and somatosensory functions have significant influence toward everyday lives and are physical functions to study for the construction of urgently needed physical function databases of the elderly. This study concentrates on visual functions among the variety of physical functions of the elderly. To measure various visual functions of the elderly, a measurement room for the elderly has been developed, which can mimic everyday lives and perform measurements of visual functions with subjects in seated position. The measurement items for the construction of the database were capabilities in everyday vision according to changes in arrangement of colors and light intensity and capabilities in everyday vision, color distinction, dark adaptation, and light glare against changes in contrast.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.11-14
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• 2007

현재, 새로운 조명광원으로서 백색 LED가 기대되고 있으며, 이를 이용하는 조명이 확대되어 실용화 될 것으로 예상된다. LED 광원을 이용하여 조명기구를 제작하고 이것을 실내조명으로 사용할 때 조명기구에 의한 글레어가 편안함을 주는지 불편함을 주는지에 대한 평가가 요구된다. 실내 조명환경에 대한 불쾌글레어를 평가하기 위해 UGR(Unified Glare Rating)을 추천하고 있다. 그러나 균일한 글레어 광원의 평균휘도를 이용하여 계산된 종래의 불쾌글레어 평가법들은 불균일한 휘도를 갖는 LED 조명기구에 대해서는 적용하기 어렵게 될 것으로 판단된다. 그래서 UGR를 이용하였을 경우, 균일한 휘도를 갖는 조명기구와 불균일한 휘도를 갖는 조명기구에 대해서 어떠한 차이가 있는지 다음의 불쾌글레어의 주관평가 실험을 수행하였다. 평균휘도가 같고 최대 휘도와 최소 휘도가 다른 조명기구(균일한 휘도를 갖는 조명기구 1종과 불균일한 휘도를 갖는 조명기구 2종)를 글레어 광원으로 사용하였다. 입체각(${\omega}$)과 위치지수(Position Index)를 고정시키고 배경휘도($L_b$)와 광원휘도($L_s$)를 임의로 변화시켰다. 주어진 환경에서 피험자로 하여금 얼마나 편안하진 또는 불편한지에 대한 느낌을 값으로 평가하도록 하였다. 우선, UGR과 주관평가 사이에 차이가 나타났으며, 이는 동 서양에 따른 문화적 및 생리적 차이에 기인한다고 생각된다. 다음으로 균일한 휘도를 갖는 조명기구보다 불균일한 휘도를 갖는 LED 조명기구가 더 높은 값을 할당 받아 LED 조명기구가 불쾌감을 더 유발시키는 것으로 나타났다. 또한 LED 소자 간격에 따른 영향은 글레어 광원의 휘도가 높아질수록 크게 나타났으며, 배경휘도에 대해서도 광원의 휘도가 높아질수록 LED 소자 간격의 차이에 의한 영향이 나타났다. 따라서 UGR식은 균일한 휘도를 갖는 조명기구에 적용하기에는 적합하지만, 불균일한 휘도를 갖는 조명기구에 적용하기에는 부적합하다고 판단된다.

• KIEAE Journal
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• v.15 no.3
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• pp.49-56
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• 2015

Purpose: Due to recent increase on energy consumption for light in building, many studies to mitigate this issue have been conducted. Various researches have been carried out to suggest light shelf as one of the solutions, but researches for its reflectivity is very few. In fact, existing research on light shelf shows that utilizing more than 90% of high-illumination materials causes imbalance of glare and illuminance. Method: Therefore this research aimed to evaluate the performance of light shelves depending on reflectivity and to identify proper solution through test-bed. Result: The results are following: 1) Increased reflectivity generally contributed to increase of indoor illuminance but degrade uniformity factor related with indoor comfort of light environment. 2) The $0^{\circ}fixed$ light shelf with 75% of reflectivity and width of 300mm and 40mm appeared to consume more energy than other shelves. Therefore, it is analyzed as unsuitable. 3) This research was conducted by calculating appropriate angle of light shelf around winter and summer solstices and vernal/autumnal equinox. Based on this, performance evaluation was undertaken depending on reflectivity of movable light shelf, which is activated by external sources and can be applied with lower reflectivity than fixed shelf. However, one exception was a movable shelf with width of 600mm that increased light energy consumption when 75% of reflectivity was applied. 4) Performance evaluation of fixed and movable light shelf showed that the shelf with 80% of reflectivity came up with suitable results, but 75% of reflectivity may be applied depending on the width and angle of the shelf. This research is meaningful in that estimation of appropriate reflectivity of light shelf can resolve the glare problem and improve light environment, and further research would be desirable under more diverse conditions to identify proper solution.

• 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.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.1
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• pp.21-28
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• 2008

Diagnostic display monitor QA according to AAPM TG18 is usually performed by PACS administrator, product manager and reading doctor, and for acceptance testing and periodic quality control evaluation, a combination of visual and quantitative tests can be used, as outlined in sections 5 and 6 of 'assessment of display performance for medical imaging systems'. Although many display tests can be performed visually, a more objective and quantitative evaluation of display performance requires special test tools. The required instruments vary in their complexity and cost, depending on the context of the evaluation(research, acceptance testing, or quality control) and how thorough the evaluation needs to be. Objective and reliable assessment of many display characteristics can be performed with relatively inexpensive equipment, So, we made 'AAPM TG18 guiding instrument' to ues variable purpose of the evaluation of 'geometrical distortions(quantitative"', 'veiling glare(visual)' and 'sensor calibration'. The spatial measurements for the quantitative evaluation of geometric distortions, and the measurement of the veling-glare ring response function which provides information regarding the spatial extent of the luminance spread, can be performed using the TG18 guiding instrument can be used to sensor calibration to standardize the basic rate of 0% luminance when periodic calibration.