• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제36권5호
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• pp.494-499
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• 2023

In this paper, in order to apply the CF (color filter) type of the micro light emitting device (Micro LED) display method, a study on the manufacturing process of red and green phosphor inks for the inkjet process was conducted. The blue light-emitting KSF and LuAG phosphors were respectively used to control the phosphor particle size to about 1㎛, and a phosphor ink was prepared by synthesizing with a low-viscosity solution (IPA/Eg). A chemical dispersion method was applied to selectively control the dispersion characteristics in the manufacture of phosphor inks, and in particular, phosphor inks with a dispersant applied a dispersant secured stable dispersion characteristic compared to phosphor inks without a dispersion process. Therefore, it seems possible to manufacture CF for Micro LED through an inkjet process capable of controlling the dispersion characteristics of phosphor ink.

• Fashion & Textile Research Journal
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• 제19권5호
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• pp.653-660
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• 2017

Recently, consumers' evaluation and purchase of online design has been increasing due to the popularization of designing through personal computers, but there has not been enough studies on consumers' brain wave responses depending on the change of PC monitor's color. Therefore, this study investigated how brain waves changed when different background colors with gray patterns were presented through PC monitors. Six background colors with same tone of slightly low saturation were selected, including ivory, yellow, pink, green, blue and pure white as a base color. The brightness and characteristics of color used were analyzed using the luminance meter and color scales. Brain wave was measured by EEG measurement equipment. Brain wave measurement was carried out with 9 subjects at 6 points: F3, F4, T3, T4, O1, and O2. Stimuli were shown for 15 seconds each and black screens were displayed for 15 seconds between each stimulus. As results, the brain waves at O1 responded sensitively by different background colors, followed by F4 and T4. Brain index such as 'RT', 'RA', 'RG', 'RSA', and 'RAHB' showed significant differences depending on the background color at O1, whereas 'RST' differed at F4. Yellow and blue backgrounds pair was the only stimuli that showed significant differences in six brain indices mentioned. Yellow background had higher value of 'RG' at O1 and higher 'RST' at F4, indicating yellow background enhanced concentration. Blue background activated 'RT', 'RA', 'RSA', 'RAHB' at O1, meaning blue background induced calm and stable state.

• Journal of Korean Society of Water and Wastewater
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• 제11권4호
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• pp.110-117
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• 1997

Performances of combined adsorption and coagulation were evaluated as one of the options for pre-treatment or post-treatment of MSW landfills leachate and industrial landfill leachate. The COD and color removals of leachate from an old MSW landfill were 35% and 33% at an alum dose of 300mg/L with preceding PAC(powdered activated carbon) dose of 200mg/L, respectively. The COD and color removals of leachate from an young MSW landfill were 58% and 25% at an alum dose of 700mg/L and PAC dose of 500mg/L, respectively. The COD and color of biologically treated leachate from an industrial waste landfill were removed up to 32% and 68%, respectively, with pH control at addition of 500mgAlum/L and 1,000mgPAC/L. Adsorption and coagulation process with pH control showed better COD and color removals than the process without pH control for biologically treated leachate from an industrial waste landfill. The color removal was influenced greatly by pH control, while COD removal was not significant. No difference in removal efficiency was observed between adsorption-coagulation and coagulation-adsorption process. The COD removal was accomplished mainly by adsorption, while coagulation was a key mechanism of color removal. However, the mechanism of COD removal was obscure, when BOD/COD ratio was high. Maximum net increases in COD and color removals by the adsorption-coagulation process were respectively 45% and 46% compared with the unit process of adsorption or coagulation, although those removals depended on leachate characteristics. Thus, adsorption-coagulation process was considered to be effective for pre- and post-treatment of landfill leachate, and has distinct features of simple, flexible, stable and reliable operation against fluctuation leachate quality and flowrate.

• Journal of the Korea Institute of Building Construction
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• 제15권6호
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• pp.607-614
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• 2015

Generally surface finishing of building is done with water paint that performs basic water repellency and resisting. When painting the exterior of the building with water paint, application method is easy and inexpensive and it has the advantage of building maintenance. But surface finishing of water paint is easy to discolored or aging due to ultraviolet light so the effect is not satisfying than expected. Therefore this study is to analyze durability of water-repellent paints mixed with water-repellents as outer surface finishing materials, and evaluate its feasibility. Color change and color different due to the accelerated time were tested, and the feasibility was evaluated based on the test results. The experimental results of color different, brightness different and chromaticity suggested that water-repellent paints mixed with water-repellents were suitable for finishing materials. Considering overall general durability performances, stable mixing ratios were 2, 5, and 8%.

• Food Science and Preservation
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• 제9권3호
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• pp.327-331
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• 2002

To develop the use of natural pigment for food, anthocyanins were isolated from grape peels which were wasted much in korea, and their characteristics were as fellows. pH has a marked influences on the color of the grape peels anthocyanin solution(GPAS). At low pH the color of GPAS was more stable than high pH. With increasing pH the color gradually fades as colorless pseudobases are formed. It showed characteristic bathnochromic shift as the solution increased. Among the sugars tested, glucose showed the most protective effect on the color of GPAS to raise the color stability, while fructose showed an adverse effect. Orgarnic acid such as citric acid prevented the degradation of anthocyanin, but ascorbic acid lowered stability of color considerably. The effect of light on GPAS was found to be very deleterious. The pigment degradation can be minimized by shielding the light from the pigment solution.

• Journal of the Korea Society of Computer and Information
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• 제15권3호
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• pp.27-35
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• 2010

Accurately extracting skin color regions is very important in various areas such as face recognition and tracking, facial expression recognition, adult image identification, health-care, and so forth. In this paper, we evaluate the performances of several skin color detection algorithms in indoor environments by changing the distance between the camera and the object as well as the background colors of the object. The distance is from 60cm to 120cm and the background colors are white, black, orange, pink, and yellow, respectively. The algorithms that we use for the performance evaluation are Peer algorithm, NNYUV, NNHSV, LutYUV, and Kimset algorithm. The experimental results show that NNHSV, NNYUV and LutYUV algorithm are stable, but the other algorithms are somewhat sensitive to the changes of backgrounds. As a result, we expect that the comparative experimental results of this paper will be used very effectively when developing a new skin color extraction algorithm which are very robust to dynamic real environments.

• Journal of the Korean Ceramic Society
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• 제45권4호
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• pp.214-219
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• 2008

The zirconia ceramics are widely used because of their excellent mechanical properties. Recently, many researches to make a colored zirconia was achieved to satisfy the individual aesthetic requirements. In this study, the synthesis of black-color spinel-based inorganic pigments which are stable above $1400^{\circ}C$ and the fabrication of black-colored zirconia using the synthesized pigments are investigated. Inorganic pigments which have spinel structure and near black color were synthesized by a solid state reaction method using a $Fe_2O_3,\;Cr_2O_3$, CoO and NiO powder as a starting materials at $1600^{\circ}C$. Most of synthesized pigments were black colored spinel phases and single spinel phase was successfully synthesized at the composition range of $Cr_2O_3:25{\sim}35%,\;Fe_2O_3:45{\sim}55%$, CoO:20% and NiO:$6{\sim}10%$. The black-colored zirconia was fabricated at $1410^{\circ}C$ with the 5 wt% synthesized pigments and their properties were evaluated. The results showed that the strength value was more than 848 MPa, absorption rate was 0.1%, the brightness of color was $L^*:40{\sim}42$, the tone of color is $a^*:0.2{\sim}0.8$ and $b^*:-1.1{\sim}2.4$. As a result, the black-colored zirconia was suitable for a artificial jewelry or decoration zirconia goods.

• Restorative Dentistry and Endodontics
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• 제42권2호
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• pp.118-124
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• 2017

Objectives: This study aimed to evaluate the color stability of bulk-fill and nanohybrid resin-based composites polished with 3 different, multistep, aluminum-oxide impregnated finishing and polishing disks. Materials and Methods: Disk-shaped specimens (8 mm in diameter and 4 mm in thickness) were light-cured between two glass slabs using one nanohybid bulk-fill (Tetric EvoCeram, Ivoclar Vivadent), one micro-hybrid bulk-fill (Quixfil, Dentsply), and two nanohybrid incremental-fill (Filtek Ultimate, 3M ESPE; Herculite XRV Ultra, Kerr) resin-based composites, and aged by thermocycling (between $5-55^{\circ}C$, 3,000 cycles). Then, they were divided into subgroups according to the polishing procedure as SwissFlex ($Colt\grave{e}ne/Whaledent$), Optidisc (Kerr), and Praxis TDV (TDV Dental) (n = 12 per subgroup). One surface of each specimen was left unpolished. All specimens were immersed in coffee solution at $37^{\circ}C$. The color differences (${\Delta}E$) were measured after 1 and 7 days of storage using a colorimeter based on CIE Lab system. The data were analyzed by univariate ANOVA, Mann-Whitney U test, and Friedmann tests (${\alpha}=0.05$). Results: Univariate ANOVA detected significant interactions between polishing procedure and composite resin and polishing procedure and storage time (p < 0.05). Significant color changes were detected after 1 day storage in coffee solution (p < 0.05), except Quixfil/Optidisc which was color-stable after 7 days (p > 0.05). Polishing reduced the discoloration resistance of Tetric EvoCeram/SwissFlex, Tetric EvoCeram/Praxis TDV, Quixfil-SwissFlex, and all Herculite XRV Ultra groups after 7 days storage (p < 0.05). Conclusions: Discoloration resistance of bulk-fill resin-based composites can be significantly affected by the polishing procedures.

• FLOWER RESEARCH JOURNAL
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• 제16권1호
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• pp.49-56
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• 2008

Typical rose flowers, 'Red Corvette (red)', 'Nobless (pink)', 'Golden Metal (yellow)', and 'Rose Yumi (white)', were used as experimental materials to examine flower color changes as affected by pressing method and light treatment for four weeks and eight weeks by 2,000 lux fluorescent light at a 16 hours daylength. Pressing materials in silicagel mat resulted in the least change after pressing and light treatment for all kinds. On the contrary, an electric pressing device caused color to change to brown. Flower colors deteriorated the most by an electric pressing device made in Korea for pink rose; an electric pressing device made in Japan for white rose; and paper sheet made in Korea for red rose. The sequence of degree in severity of color change after pressing was pink, yellow, and white roses. Light treatment brought about the most extreme color change in yellow 'Nobless' rose, while other three cultivars were rather stable in change of color.

• Animal Bioscience
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• 제36권5호
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• pp.785-796
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• 2023

Objective: We aimed to evaluate the color and oxidative stability of beef gluteus medius (GM) from cattle raised in organic and non-organic production systems. Methods: The GM samples (n = 10) were obtained from organic (ORG; n = 5) or nonorganic (NORG; n = 5) beef samples, sliced into 2.54-cm steaks, packaged in aerobic conditions, and stored for nine days at 4℃. ORG and NORG steaks were compared regarding myoglobin concentration, pH, instrumental color, delta E (ΔE), metmyoglobin reducing activity (MRA), and lipid oxidation on days 0, 5, and 9. Results: Feeding system did not influence (p>0.05) the myoglobin concentration. ORG steaks exhibited greater (p<0.05) meat pH, yellowness, and MRA, whereas NORG steaks exhibited greater (p<0.05) redness, chroma, R630/580, delta E, and lipid oxidation. ORG and NORG steaks exhibited similar (p>0.05) lightness and hue angle. During storage, ORG and NORG exhibited an increase in muscle pH, hue angle, and lipid oxidation; and a decrease (p<0.05) in redness, yellowness, chroma, and color stability (R630/580). Both samples exhibited a stable (p>0.05) pattern for lightness and MRA. Conclusion: Therefore, the production system can affect beef color and lipid stability during storage.