• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.18-25
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• 2014

In this paper, tried to find out the proper luminous intensity distribution for the cabin with low-level height by analyzing the changing tendency of discomfort glare according to luminous intensity distribution of marine indoor luminaires using Unified Glare Rating(UGR). First, we analyzed UGR of the indoor luminaires in the existing cabin, and then evaluated influence on luminous intensity distributions of marine indoor luminaire. The results showed that $cos^2{\Theta}$ distribution got almost low UGR results regardless of height and UGR 16.5 in cabin height of 2m. However, Gaussian distribution with the same beam angle showed that UGR results consistently increased by getting lower height and UGR 20.7 in the same height. In conclusion, the $cos^2{\Theta}$ distribution in consideration of luminous intensity on the direction of observer's eye was appropriate for general cabin indoor luminaires because it decreased UGR in the low-level height.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.575-584
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• 2010

The aim of study is to suggest the design procedure of automobile headlamp by considering driver's experience in regard of the visibility and glare during nighttime driving. The characteristics of driver were investigated in terms of the drivers' cognitive ability and reaction time, headlamp specification and visibility, light source and glare. And, the degree of visual discomfort was categorized and recognized as a tool to represent the subjective user experience. The UX point of view was stated when the existing results were seemingly lacking of it. The visual comfort and safety of elderly drivers were also discussed by reviewing the studies of ageing regarding the visibility and driving responses. Finally, this study suggested how to reduce the negative effect of nighttime driving due to the height of headlamp, angle of lighting, color spectrum, discomfort glare, source of light by using the UX perspective and methodology.

• KIEAE Journal
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• v.12 no.6
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• pp.107-112
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• 2012

The purpose of this study is to determine the optimum slat angle of the venetian blind which was applied at an outer skin of a curtain-wall system. The evaluation of the blind slat angle was performed in terms of the comfortable visual environment and decreased energy consumption. The office building prototype was considered for the analysis and simulation variables include application of blind, blind slat angle and dimming control of lighting. The annual energy consumption and incidence rate of discomfort glare were analyzed using EnergyPlus which is developed by the U. S. Department of Energy for the detailed building energy simulation. As a result, it turns out that when the blind (reflectance: 0.5) was installed, the annual energy consumption was greater than that of the base model. However, when the dimming control was applied, the maximum energy saving of 16.3% could be achieved at a slat angle of $0^{\circ}$. In addition, in case of the base model, the incidence rate of discomfort glare was 84%, while the case of the blind with the slat angle of $0^{\circ}$ showed that the incidence rate of discomfort glare was 42.4%. Consequently, the results showed that the slat angle of $55^{\circ}$ with dimming control was the optimum strategy for the comfortable visual environment and decreased energy consumption.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.165-173
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• 2021

Anti-glare (AG) coating films are applied to various display fields such as liquid crystal displays, LED lighting, and touch panels. In this study, micrometer-sized silica particles were added as fillers in the UV-curable coating solutions to provide anti-glare effect. During this process, the effects of the particle size, content, stirring time, and mixing ratio of silica particles of different sizes were investigated on the haze values and visible light transmittance of the coating films. As a result, as the size of the silica particles increased and the content of the silica particles increased, the haze values increased, but the visible light transmittance decreased. On the other hand, the stirring time did not significantly affect the haze value and transmittance of coating films. In addition, as the mixing ratio of large-sized silica particles increased, the haze value increased, but on the contrary, the visible light transmittance decreased.

• Applied Science and Convergence Technology
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• v.25 no.6
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• pp.133-137
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• 2016

The surface treatment of cover glass for conversion efficiency of photovoltaic cell is important to reduce reflectivity and to increase the incident light. In this work, random textured anti glare (RTAG) glass was prepared by wet surface coating method. Optical properties due to the changes of surface morphology of RTAG glass were compared and conversion efficiency of photovoltaic cell was researched. Grain size and changes of surface morphologies formed with surface etching time greatly affected optical transmittance and transmission haze. Current density (Jsc) were high at the condition when surface morphologies reflection haze were low and transmission haze were high. Jsc was $40.0mA/cm^2$ at glancing angle of $90^{\circ}$. Incidence light source was strongly influenced by surface treatment of cover glass at high incidence angle but was hardly affected light source at the low angle of incidence.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.394-401
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• 2004

In this study the mechanical behaviors of fiber metal laminates(FMLs) such as ARALL, GLARE and CARE which are recently developed as new structural materials and known to have excellent fatigue resistant characteristics while with relatively low densities compared to the conventional aluminum materials, are considered through the classical lamination theory. The mechanical properties such as elastic moduli, thermal expansion coefficients and hygro-thermally induced residual stresses in the fiber metal laminates are obtained and compared each other. Also, carpet plots of effective elastic moduli, Poisson's ratio and the thermal expansion coefficient for GLARE FML are plotted.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.303-308
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• 2018

Currently hydrofluoric acid (HF) based glass etch method is widely used for anti-glare (AG) surface treatment since it can effectively alleviate the specular reflection problem with relatively low processing cost. However, due to the environmental regulation and safety problem, it is essential to develop alternative technology to replace this method. For this, in this paper, we propose sand blasting based AG surface treatment method for display glass. To characterize the sand blasting process, surface roughness, haze, surface durability, and flatness are considered as process outputs and central composite design (CCD) method and response surface model (RSM) method are applied to model each process output. Models for surface roughness and haze showed 96.44% and 97.24% of R-squared values, respectively and they can be applied to optimize AG surface treatment process for various haze level requirements of display industries.

• Journal of the Korean housing association
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• v.23 no.1
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• pp.27-41
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• 2012

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight and solar irradiation by opening/closing of a blind. As previous researches on blind controls have limited outdoor environmental conditions to those in specific regions, orientations and dates, these resulted in problems at various conditions for general-purpose application. Major problem is that the time interval and amount of blind movement do not meet the control objective at the end of control zone and discontinuous curve. To overcome these limitations revealed in the previous researches, following tasks were performed in this study. 1) To establish the control objective to accomplish the goal of this study. 2) To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various profile angle curves. 3) To validate the general-purpose applicability and performance of the developed control methods and algorithms by simulation and its data analysis at various conditions. It was found that the proposed methods and algorithms can prevent the direct glare on the work-plane at all the time and also increase the incoming daylight and solar irradiation.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.64-68
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• 2014

This paper introduces the use of a crown-shaped (CR) lens to effectively diffuse the light from a light-emitting diode (LED) without any loss in the light intensity, in contrast to polymer-bulb-type diffusers. The diffusion lens was designed based on the Snell's law, which describes the physical path of a ray passing through the boundary between different media. CR lenses were fabricated by polydimethylsiloxane (PDMS) casting and UV-embossing processes, which used a pre-designed metal mold and UV-curable resin, respectively. Through experiments and optical evaluations, it was verified that the newly proposed CR lens not only decreased the vertical light strength and glare effect from an LED light source but also improved the diffusion characteristics while maintaining the quality of the LED's light intensity.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.125-131
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• 2012

PURPOSES : Road lighting facilities increase the visibility of road at night in order to improve traffic driver safety and comfort. Generally speaking, current pole lighting has a tendency to create problems of glare and flicker. The phenomenon of glare gives discomfort due to increase of scattered light, when high luminance is in driver's field of view. The phenomenon of flicker occurs due to the driver passing through discontinuous pockets of pole lighting areas. These phenomenon increase eye strain and decrease driver safety. METHODS : Low height line lighting that distributes light lower than driver's eye level has been developed and evaluated to reduce the problems linked to current pole lighting. A test was undertaken with 4 conditions(turn on the general pole lighting, turn off alternate pole lighting, turn on the line lighting and line lighting with 50% dimming). A driver written survey was conducted in order to gain driver feedback. RESULTS : Pupil size and brow frequency compared with degree in pole lighting are reduced. CONCLUSIONS : Low height line lighting environment makes drivers more comfortable than pole lighting environment and is positive lighting method in the energy saving and landscape aspect.