• Fire Science and Engineering
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• v.17 no.4
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• pp.36-41
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• 2003

This experimental study shows the combustion characteristics for each coating thickness of water and oil paint which are used as fire retardant paints that prevent fire propagation through cables in underground culverts and trays. To evaluate combustion characteristics, smoke density(ASTM E 662) and Limited Oxygen Index(ASTM D 2863) experiment method was used. As the results of this study, the combustion characteristics of fire retardant paints produced the following : (a) The molt suitable coating thickness of fire retardant paint was 1.5∼2.0 mm in water paint and 0.2 mm in oil paint. (b) Flaming method in experiments of smoke density were found to be higher than Non-flaming method. (c) Water paint has the fire retardant effect and characteristics better than oil paint in measurement results of smoke density and oxygen index. (d) The oxygen index of water and oil fire retardant was able to know that it was satisfied a standard (30 or above).

• Transactions on Electrical and Electronic Materials
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• v.1 no.4
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• pp.11-15
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• 2000

This paper presents a process optimization of antireflection (AR) coating on crystalline Si solar cells. Theoretical and experimental investigations were performed on a double-layer AR(DLAR) coating of MgFe$_2$/GeO$_2$. We investigated GeO$_2$ films as an AR layer because they have a proper refractive index of 2.46 and demonstrate the same lattice constant as Si substrate. RF sputter grown GeO$_2$ film showed deposition temperature strong dependence. The GeO$_2$ at 400$\^{C}$ exhibited a strong (111) preferred orientation and the lowest surface roughness of 6.87 $\AA$. Refractive index of MgFe$_2$film was measured as 1.386 for the most of growth temperature. An optimized DLAR coating showed a reflectance as low as 2.04% in the wavelengths ranged from 0.4 ㎛ to 1.1 ㎛. Solar cells with a structure of MgFe$_2$/GeO$_2$/Ag/N$\^$+//p-type Si/P$\^$+//Al were investigated with the without DLAR coatings. We achieved the efficiency of solar cells greater than 15% with 3.12% improvement with DLAR coatings. Further details about MgFe$_2$,GeO$_2$ films, and cell fabrication parameters are presented in this paper.

• ETRI Journal
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• v.31 no.6
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• pp.675-679
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• 2009

$Ti_xSi_{1-x}O_y$ (TSO) thin films are fabricated using plasma-enhanced atomic layer deposition. The Ti content in the TSO films is controlled by adjusting the sub-cycle ratio of $TiO_2$ and $SiO_2$. The refractive indices of $SiO_2$ and $TiO_2$ are 1.4 and 2.4, respectively. Hence, tailoring of the refractivity indices from 1.4 to 2.4 is feasible. The controllability of the refractive index and film thickness enables application of an antireflection coating layer to TSO films for use as a thin film solar cell. The TSO coating layer on an Si wafer dramatically reduces reflectivity compared to a bare Si wafer. In the measurement of the current-voltage characteristics, a nonlinear coefficient of 13.6 is obtained in the TSO films.

• Journal of the Korean Ceramic Society
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• v.42 no.6 s.277
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• pp.399-404
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• 2005

Anti-reflection film was coated by using spherical silica nano colloidal particles and fumed silica particles. Silica colloid sol was reserved between two inclined slide glasses by capillary force, and particles were stacked to form a film onto the substrate as the upper glass was sliding. The deposition processes were studied to enhance the wavelength dependency of the light transmittance and to control the effective refractive index of the film. Both of the spherical and fumed silica particles showed an enhancement of $4.0-4.4\%$ in light transmittance by one step coating. The dependence of the transmittance on wavelength was largely improved at the longer wavelength by partial coating of fumed particles on the film of spherical particles. The effective refractive index of the film was controlled by removing latex particles that were co-deposited with silica particles. Using this process the light reflectance from one side of the glass substrate could be reduced from $4.2\%$ to $0.6\%$ although zero reflectance was not achieved due to the agglomeration of the latex particles.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.821-825
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• 2015

Anti-reflective (AR) thin film was fabricated on a glass substrate by sol-gel method. The coating solution was synthesized with TEOS (tetraethlyorthosilicate) and poly ethylene glycol (PEG, 4.0 wt%). As the withdrawal speed of coating was changed from 0.1 mm/sec to 0.3 mm/sec, the thickness and refractive index of prepared thin films were changed. The reflectance and transmittance of coating glass fabricated by the withdrawal speed of 0.1 mm/sec were 0.62% and 95.0% in visible light range. The refractive index and thickness of single layer thin film were n= 1.29 and ca. 99.0 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.61-66
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• 2002

A method for designing antireflection (AR) and antistatic (AS) coating layer by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR coating is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The poly(3,4-ethylenedioxythiophene) which has the surface resistivity of 10$^4$Ω/$\square$ is used as a conductive layer. Optical constant of each ARAS coating layers such as refractive index and optical thickness were measured by 7he spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the risible region. The reflectance of ARAS films on glass substrate was below 1 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.341-350
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• 2023

In the present study, effects of a thin Zn-flash coating on hydrogen evolution, infusion, and embrittlement of advanced high strength steel during electro-galvanizing were examined. The electrochemical permeation technique in conjunction with impedance spectroscopy was employed under applied cathodic polarization. Moreover, a slow-strain rate test was conducted to evaluate loss of elongation (i.e., indicative of hydrogen embrittlement (HE)) and examine fracture surfaces. Results showed that the presence of a thin Zn-flash coating, even when it was not distributed uniformly, reduced hydrogen evolution rate and substantially impeded infusion of hydrogen into the steel substrate. This was primarily due to a hydrogen overvoltage on Zn coating and trapping of hydrogen at the interface of Zn coating/flash coating/steel substrate. Consequently, the sample with flash coating had a smaller HE index than the sample without flash coating. These results suggest that a thin Zn-flash coating could be an effective technical strategy for mitigating HE in advanced high-strength steels.

• Journal of Oral Medicine and Pain
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• v.39 no.1
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• pp.15-21
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• 2014

Purpose: The purpose of this study was to investigate the relationship between personality type and oral hygiene controllability. Methods: Four hundred eighty-two college students in Gyeonggi-do completed the Myers-Briggs type indicator (MBTI) and a questionnaire and collected data were analyzed by SAS 9.2 program. Results: Compared to extroverted subjects, a significantly increased percentage of introverted subjects demonstrated oral malodor and stress (p<0.05). Tongue coating and stress seemed to occur the most frequently in intuition-feeling (NF) type, while oral malodor seemed to occur the most frequently in sensation-feeling (SF) type among four fuctional types. Tongue coating and stress seemed to occur the most frequently in NF type, while oral malodor seemed to occur the most frequently in sensation-perceiving (SP) type among four temperaments. Significantly increased mean scales of tongue scraping index and oral hygiene controllability index were found for extroverts (p<0.05). Mean scales of tooth brushing index and oral hygiene controllability index appeared to be the highest in NF type among four fuctional types. Mean scales of tongue scraping index and oral hygiene controllability index appeared to be the highest in sensation-judging (SJ) type among four temperaments. Conclusions: Oral hygiene controllability was associated with personality type and it is necessary to develop oral health education program considering personality type.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.226-231
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• 2019

A WTCI is an important criteria for evaluating an mount of patient's tongue coating in tongue diagnosis. However, Previous WTCI tongue coating evaluation methods is a most of quantitatively measuring ration of the extracted tongue coating region and tongue body region, which has a non-objective measurement problem occurring by exposure conditions of tongue image or the recognition performance of tongue coating. Therefore, a WTCI based on deep learning is proposed for classifying an amount of tonger coating in this paper. This is applying the AI deep learning method using big data. to WTCI for evaluating an amount of tonger coating. In order to verify the effectiveness performance of the deep learning in tongue coating evaluating method, we classify the 3 types class(no coating, some coating, intense coating) of an amount of tongue coating by using CNN model. As a results by testing a building the tongue coating sample images for learning and verification of CNN model, proposed method is showed 96.7% with respect to the accuracy of classifying an amount of tongue coating.

• The Journal of Internal Korean Medicine
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• v.29 no.1
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• pp.258-264
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• 2008

Objectives : The aim of this study was to confirm the characteristics of oral malodor patients by evaluating the differences of salivary flow rate, secretory immunoglobulin A (sIgA) level in saliva between the patient and control groups, and the correlation with the tongue coating, volatile sulfur compound (VSC), salivary flow rate and sIgA level in saliva in the patients group. Methods : Forty-seven patients with oral malodor and twenty healthy volunteers were included in this study. Their tongue coating was assessed with the Winkel tongue coating index, and salivary flow rate, sIgA concentrations in saliva and the level of VSC in oral cavity were measured. Results : There were no significant differences of the salivary flow rate and the sIgA level in saliva between the patient and control groups, but there was a significant relationship between the accumulation of tongue coating and the level of VSC in oral cavity. Conclusions : Our results suggest that tongue coating is closely related to oral malodor, but further studies are needed to confirm the relationship between tongue coating and sIgA level in saliva.