• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.124-128
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• 2017

A light guide improves the spatial resolution of a gamma ray imaging system by diffusing the scintillation light. Similarly, light diffusion film, which has been applied to flat-panel-display engineering, spreads the light from the light guide panel. In this study, we adopted light diffusion film for the light guide of a gamma ray imaging system, and evaluated its diffusion characteristics. We compared the light diffusion performance of the film to an ordinary acrylic plate. As a result, the diffusion film widely spreads scintillation light. As for the thickness of the light guide, we acquired more distinct images with three films overlapped than with an acrylic plate. We expect light diffusion film to be a promising candidate for light guides in gamma ray imaging systems.

• KIEAE Journal
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• v.17 no.3
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• pp.91-97
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• 2017

Purpose: Various studies on a light shelf are in progress, but it has the problem of glare occurrence. The present study suggested a diffusion film as the method for resolving the glare problem, and aimed to establish light shelf-related basic data by conducting the performance evaluation of a light shelf depending on the installation position of the diffusion film. Method: To carry out the light shelf performance evaluation depending on the diffusion film installation position, three cases were established: no diffusion film installation (Case 1), diffusion film installation on the reflector (Case 2), and diffusion film installation on the upper glass surface of the window for light shelf installation (Case 3); and the energy reduction performance, luminance, and luminance contrast were analyzed based on a testbed. Result: The conclusions of this study are as follows. 1) When the diffusion film was applied, the amount of light introduced through the light shelf decreased, and the average indoor illumination decreased accordingly. 2) For Case 3, the lighting energy reduction performance was identical to the lighting energy reduction efficiency of the existing light shelf; and for Case 2, it was found to be inappropriate as the lighting energy consumption increased compared to that of the existing light shelf. 3) The analysis of the glare for the cases established in this study showed that the luminance contrast was low for Case 3, and thus the glare problem could be minimized. 4) The specific angle of the light shelf could induce the glare problem by increasing the luminance depending on the external condition. 5) Based on the aforementioned contents, the installation position of the diffusion film for improving the lighting performance and glare problem of the light shelf was found to be the upper glass surface of the window for light shelf installation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.144-147
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• 2003

Cu+ ions drift diffusion in formal oxide film and SiOCH film for interlayer dielectric is evaluated. The diffusion is investigated by measuring shift in the flatband voltage of capacitance/voltage measurements on Cu gate capacitors after bias temperature stressing. At a field of 0.2MV/cm and temperature $200^{\circ}C,\;300^{\circ}C,\;400^{\circ}C,\;500^{\circ}C$ for 10min, 30min, 60min. The Cu+ ions drift rate of $SiOCH(k=2.85{\pm}0.03)$ film is considerable lower than termal oxide. As a result of the experiment, SiOCH film is higher than Thermal oxide film for Cu+ drift diffusion resistance. The important conclusion is that SiOCH film will solve a causing reliability problems aganist Cu+ drift diffuion in dielectric materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1262-1265
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• 2004

To increase the performance of the light diffusion films, we controlled the three dimensional microstructure of the organic fillers(beads). The refractive index, the size distribution and the three dimensional distribution of beads play an important role to determine the performance of light diffusion films for the backlight unit of TFT-LCD.

• Korean Management Science Review
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• v.32 no.1
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• pp.133-145
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• 2015

Motion picture industry in Korea has been growing constantly and aroused various kinds of research attention. Particularly, the introduction of official box-office database service brought quantitative studies. However, approaches based on diffusion models have been rarely found with domestic film markets. In addition to the fundamental statistical review on Korea and US film markets, we applied a diffusion model to daily box-office revenue. Unlike conventional preference of Gamma distribution on the film markets, estimation results proved that BMIC can also explain the trend of daily revenue successfully. The comparison with BMIC showed that there is a distinctive difference in diffusion patterns of Korea and US film markets. Generally, word-of-mouth effect appeared more significant in Korea.

• Textile Coloration and Finishing
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• v.19 no.6
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• pp.21-27
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• 2007

The factors which affect the absorption and diffusion of disperse dye in print paste for polyester film were investigated using film roll method. When Emvatex print paste of different disperse dye concentrations were fixed by high temperature steaming(HTS) for 2 hr at $190^{\circ}C$, the dye uptake and diffusion distance of 50g/kg dye concentration for PET film were very low, but those of 100$\sim$300g/kg were increased with increasing dye concentration. It was found that sodium alginate(5%) was more effective for the absorption and diffusion of disperse dye to PET film than CMC(3%) and Emvatex(18%), and Emvatex showed comparatively low absorption in three thickeners used. The dye uptake and diffusion distance of disperse dye in sodium alginate paste for PET film were increased with increasing paste thickness to $160\sim180{\mu}m$, but were decreased at $200\sim220{\mu}m$ in both fixations of baking and HTS for 2 hr at $190^{\circ}C$, and were far more largely increased by fixation of HTS than baking because steam was very important for fixation. Also it was confirmed that dye uptake was slightly increased as steam supply pressure was raised from 1 $kg/cm^2$ to 2 $kg/cm^2$, andthe dye uptake and diffusion distance of disperse dye were outstandingly increased with raising fixing temperature from $170^{\circ}C$ to $190^{\circ}C$ and fixing time from 0.5 hr to 3 hr in the fixation of HTS.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.1
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• pp.72-80
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• 1999

Separation of VOCs(Volatile Organic Compounds) in Water Using Activated Carbon is known to be effective. Activated Carbon has been and will be employed in many water treatment plants. Simplified plug flow homogeneous surface diffusion model(PFHSDM) has been used to predict adsorption of organic matter. Finite Element Method(FEM) was used to analyze the model. Out of water quality control substances, benzene, toluene and tetrachloroethylene were used in the small column test. Film diffusion coefficients and surface diffusion coefficients were obtained from the column test, and were compared with the modeling results. Mc Cune, Williamson, William and Kataoka model, were compared with film diffusion coefficients obtained in the test. McCune model was fitted best for those VOCs used in this experiment. Film diffusion coefficients of VOCs obtained were benzene 0.265 cm/min, toluene 0.348 cm/min and tetrachloroethylene 0.298 cm/min. Surface diffusion coefficients of VOCs obtained were benzene $6.36{\times}10^{-8}cm^2/min$, toluene $3.20{\times}10-8cm2/min$, and tetrachloruethylene $4.94{\times}10^{-8}cm^2/min$.

• Textile Coloration and Finishing
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• v.2 no.4
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• pp.231-236
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• 1990

The diffusion coefficient of C.I. Disperse Red 4 in the dyeing of carrier-pretreated poly (ethylene terephthalate) film was Investigated by Sekido's film-rolled method. From the result it was shown that the diffusion coefficient increases exponentially with the content-ration of carrier in the film, and, for the films containing same concentration of carrier, the carrier effect was enhanced with the molar volume of the carriers. The greater carrier effect was accompanied by the decrease in diffusion activation energy and entropy, which shows that the carrier with larger molar volume plasticizes PET film to more extent.

• Journal of the Korean Ceramic Society
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• v.54 no.5
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• pp.429-437
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• 2017

Micro hollow plate type silica with low refraction properties was synthesized and its hollow structure was applied as an optical structure to develop a light diffusion material that simultaneously satisfies the requirements of good light diffusibility, high transmissibility, and high luminance. The developed light diffusion material was applied to a light diffusion film and the film's optical properties were assessed. Hollow silica was synthesized by precipitation method using $Mg(OH)_2$ core particles, sodium silicate, and ammonium sulfate as the silica precursors. The concentration of the silica precursor was adjusted to control hollow silica shell thickness. The total light transmittance of the light diffusion film composed of the hollow silica was 94.55%, which was 4.57% higher than that of the PC film; new film's haze was 71.20%, which was 70.9% higher. Furthermore, the luminance increased by 5.34% compared to that of the light source. The reason for the results is not only that the micro plate type hollow silica, which has a low refractive property, played a role in reducing the difference in refractive index between the medium boundaries, but also that there was a light-concentrating effect due to the changing of light paths to the front direction inside the hollow structure. Optical simulation verified the enhanced optical properties when hollow silica was applied to the light diffusion film.

• Journal of the Korean Applied Science and Technology
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• v.20 no.4
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• pp.332-340
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• 2003

Crosslinked poly(methyl methacrylate) particles from 2.4 to $8.1{\mu}m$ in diameter were prepared by homogenized suspension polymerization. The effect of polymerization parameters such as homogenizing speed, homogenizing time and stabilizer concentration on the particle size were examined. Optical diffusion films were prepared with the crosslinked poly(methyl methacrylate) particles. The effect of film thickness, particle size, and particle size distribution on transmittance and haze of optical diffusion film was examined. Transmittance of optical diffusion film increased with increasing particle size and decreasing film thickness. Haze increased with increasing film thickness and decreasing particle size. We also found the existence of an optimum ratio for optical performance when the mixture of small particle and large particle was used.