• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.27-31
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• 2011

ZnS:Mn yellow phosphors doped with Sm for white light emitting diodes were synthesized by solid state reaction method. These sample showed the characteristic X-ray diffraction patterns for main peak (110) of ZnS:Mn,Sm. Photoluminescence excitation spectra originated from $Mn^{2+}$ were ranged from 450 nm to 500 nm. The yellow emission at around 580 nm was associated with $^4T_1{\rightarrow}^6A_1$ transition of $Mn^{2+}$ ions in ZnS:Mn,Sm phosphors. The highest photolum inescence intensity of the phosphors under 405 nm and 450 nm excitation was obtained at Sm concentration of 1 mol%. The enhanced photoluminescent intensity in the ZnS:Mn,Sm phosphors was interpreted by energy transfer from Sm to Mn. The highest luminescent intensity of white LED was obtained at the epoxy-to-yellow phosphor ratio of 1:3. At this ratio, the CIE chromaticity of the white LED was X=0.3886 and Y=0.2928.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.159-164
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• 2015

Color is distinguished due to the light in which natural light is reflected by object and made with combination of RGB(red, green, blue; three colors). This study proposes color analysis system with optical method to be used conveniently. Color information of sample is determined with the optical sensor. By using the CIE diagram in particular, it detects purity value and wavelength. The method to distinguish color is very economical, simple, and convenient. The result can be used to confirm accurate information of color for various applications.

• 전자공학회논문지 IE
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• v.47 no.4
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• pp.53-58
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• 2010

In this paper we propose symbol decision method reflecting the color non-uniformity in 3-dimensional color space. By comparing with 2-dimensional color space decision method, we show the superiority of BER performance of the proposed method. Proposed method may reflect the non-uniformity since the symbol decision boundary in color space is transformed from 3D RGB space, and one dimension corresponding to Y value is added. Therefore, we can obtain the better BER performance by using the symbol decision method in 3D color space. In this paper, through numerical simulation, show the superior BER performance of 3D color space symbol decision method compared with 2D color space symbol decision method under AWGN and common mode noise channel.

• The Journal of Advanced Prosthodontics
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• v.7 no.5
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• pp.400-405
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• 2015

PURPOSE. The purpose of this study is to mix dental ceramic powder in varying ratios and evaluate the effect of the mixing ratio on color and translucency. MATERIALS AND METHODS. The ceramic powder of shade A3 of the same product was mixed with the shade A2 of three products: IPS e.max Ceram (Ivoclar Vivadent, Schaan, Liechtenstein), Vintage Halo (SHOFU Inc., Kyoto, Japan), and Ceramco 3 (Ceramco-Dentsply, Burlington, NJ, USA) in the following fixed ratios (0 wt%, 25 wt%, 50 wt%, 75 wt%, and 100 wt%) and then fired. A total of 150 specimen of ceramic fired were manufactured in a regular size (W: 8.5 mm, L: 10.5 mm, and H: 1.5 mm). For color and translucency, $L^*$, $a^*$, and $b^*$ were measured and Two-way analysis of variance (ANOVA) and One-way analysis of variance (ANOVA) were used for data analysis (${\alpha}$=0.05). RESULTS. The higher the mixing ratio was, $L^*$, $a^*$, and $b^*$ of IPS e.max Ceram were all increased, and $L^*$ of Vintage Halo was reduced and $a^*$ and $b^*$ were increased. $L^*$ and $a^*$ of Ceramco3 were reduced and $b^*$ of Ceramco3 was increased. Color difference (${\Delta}E^*ab$) was increased in all three products as the mixing ratio got higher. Increased mixing ratios resulted in decreased translucency parameter (TP) values for IPS e.max Ceram but increased TP values for Vintage Halo and Ceramco3. CONCLUSION. In this limited study, CIE $L^*$, $a^*$, and $b^*$ were influenced by the mixing ratio of the A3 powders and porcelain powder mixtures represented a various color and translucency.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.4
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• pp.549-559
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• 1994

The purpose of this study was to study accumlated residual soils which may be one of the causes for yellowing of worn cloths. Wear and wash tests of white cotton undershirts were repeated at 30 households sellected at random over a period of 60 days. Laundry conditions were similar to home laundry habits in a fact-finding survey, using a powdery heavy duty detergent containing no enzymes or enzymes. The subjects in this study were survey of laundry actual condition, the undershirts from prior to and after the final washing was measured residual soils, $L^*a^*b^*$ value and mellowness index of CIE system. D3ta were analysed by simple correlation analysis of wear and wash cycle, residual soils, whiteness The results obtained were summarized as follows: 1. Using pattern of washing machine, Presoaking was no singinificant differnece in general characteristics of survey respondent. Laundry frequency was significant difference in income level, occupation of housewives whether or not. Use of cold and hot water was significant difference in residence shape. 2. The analyzed consequences of recognition and actual behavior in connection with laundry were found variables each other to have independence or not. 3. Amount of residual sebum soils is using non-enzyme detergent were much more than in using enzyme detergent, increased linearly with increase of the number of wear and wash cycles. 4. Residual protein soils with increase of the number wear and wash cycles less than in laundering more easy than sebum soils. Since accumulated residual sebum soils were much more than residual protein soils. 5. Increase of residual soils was raised mellowness index and diminshed whiteness. yellowness index of residual sebum soils was higher than protein soils. If increase of whiteness will be incresed, amount of residual sebum soils will be decreased sebum soils. Because amount of residual sebum soils much more than protein soils, yellowness index of residual sebum soils was more higher than that of protein soils.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.693-700
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• 2011

To evaluate the antioxidant effects of vitamin C, vitamin E and sorghum bran, alone or in combination on chicken sausages, 9 kg of chicken thigh meat was prepared. All thigh meat was divided into seven different batches as follows; no antioxidant (CON); vitamin C (VTC), vitamin E (VTE) or sorghum bran (SOR) at 0.02%; or three different combination ratios of vitamin C, vitamin E and sorghum bran at 0.02% (VT2, 2:1:1; VT4, 4:1:1; VT6, 6:1:1). All cooked sausages were stored at $4^{\circ}C$, and six sausages per treatment were used for chemical analysis on five different storage days. As the addition of vitamin E was increased, sausages stored for 10 d had decreased redness; thereby, VTE showed the lowest CIE $a^*$ (p<0.05). Sausages mixed with vitamins and sorghum bran combinations had lower peroxide and free fatty acid values (p<0.05) when compared to sausages without antioxidants. The TBARS were the lowest in sausages containing vitamin C, vitamin E and sorghum bran at 6:1:1 ratio, and they significantly differed to CON, VTC and SOR treatments (p<0.05). Therefore, our results suggest that meat mixed with vitamins and sorghum bran had more antioxidant activity than the meat mixed with only antioxidant vitamins or without antioxidants.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.865-871
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• 2011

This study was conducted to evaluate the antioxidant effects of pumpkin leaf extracted using a 50% ethanol on ground pork during storage. The pumpkin leaf extracts were added at concentrations of 0.05 (PE-0.05), 0.1 (PE-0.1), and 0.2% (PE-0.2) to ground pork, and 0.05% of ascorbic acid (As-0.05) was added as a control. Each sample was collected after 1, 4, 7, and 10 d of storage and the pH, total viable counts (TVC), conjugated dienes (CD), free fatty acids (FFA), and thiobarbituric reaction substance (TBARS) values were measured. The pH of the pork samples decreased until day 7, and then increased thereafter, except for the control and PE-0.05 sample. Lower CIE $a^*$ values were observed for pork samples containing PE relative to As-0.05 at increasing storage time (p<0.05). The addition of PE decreased the TVC, CD, FFA and TBARS values levels in the ground pork when compared to the control during 10 d of storage. These results indicate that PE can produce notable effects on meat products, such as inhibiting lipid oxidation and discoloration.

• Journal of the Korean Ceramic Society
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• v.49 no.1
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• pp.84-89
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• 2012

Attempts were made to develop a stable gray pigment at reducing atmosphere, substituting Ti in $ZrTiO_4$ with Mn, Fe, Co and Cu The pigment synthesized at $1300~1500^{\circ}C$ by solid state method with the composition of $ZrTi_{1-x-y}A_xB_yO_4$ (x = y = 0.005, 0.015, 0.035, 0.055, 0.075, 0.095, 0.115, 0.135, 0.155, 0.175 and 0.195 mole, A = Mn(III), Fe(III), Co(II, III) and Cu(II) (chromophores), B = Sb (counterion). The pigments were fired at $1400^{\circ}C$ for 3 h with substitute amount changes of Mn, Fe, Co and Cu to $ZrTiO_4$ crystals, and analyzed by Raman spectroscopy to figure out substitute limits. Results indicated 0.035 mole for Mn, 0.115 mole for Fe, 0.015 mole for Co and 0.015 mole for Cu as substitute limits, respectively. Figs. 1, 2, 3, and 4 represent each substitute pigments of Mn, Fe, Co and Cu. Synthesized pigment was applied to a lime and a lime-magnesia glaze at 7 wt% each, and fired at reducing atmosphere of $1240^{\circ}C$, soaking time 1h. Gray color was obtained with CIE-$L^*a^*b^*$ values at 44.55, -0.65, 1.19(Mn), 40.36, -0.90, 0.30(Fe), 42.63, -0.03, -1.49(Cu) and -40.79, -0.28, -0.91(Co), respectively.

• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.583-586
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• 2009

The Tantalum nitride has attracted wide at attention as issues related to the toxicity of Cd-related materials. But in the titration process of Ta$Cl_5$ solution with $NH_4$OH, $NH_4$Cl, as a by product, was remained in the prepared Tantalum precursor. The tantalum precursor with $NH_4$Cl was nitrided by ammonolysis. The red color tone of $Ta_3N_5$ was reduced by the residual $NH_4$Cl reduce. Therefore, amorphous Tantalum precursor was prepared by filtering process with as hydrous ethanol to remove the $NH_4$Cl. In the case of using Tantalum precursor without $NH_4$Cl, we successfully synthesized the Tantalum nitride with good red color. The value of red color tone was improved from $a^*$=36.8 to $a^*$=53.0. The synthesized powder was characterized by XRD, SEM, the Nitrogen / Oxygen Determinator, TG-DTA, and the CIE $L^*a^*b^*$ colorimeter.

• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.639-642
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• 2009

The research was performed to find out the optimum firing condition for the $SnO_2-TiO_2-V_2O_5$ system yellow pigment. The pigment based on $SnO_2-V_2O_5$ system showed very intense yellow color and it was used widely in ceramics industry. Synthesized pigment, with partial substitutions of $SnO_2\;by\;TiO_2$, was fired at $1300{^{\circ}C}$ soaking 1h and it showed bright yellow color. $SnO_2-TiO_2-V_2O_5$ system was very more intensive changes in yellow color by colorimetric value $b^*$ than $SnO_2-V_2O_5$ system. Synthesized yellow pigments were characterized by X-ray diffraction (XRD), FT-IR, and UV-vis spectroscopy. The best composition for yellow pigment was 93:7:0.5(mole%) for $SnO_2-V_2O_5-TiO_2$. The measurement of CIE $L^*a^*b^*$ of pigment was $L^*(78.82),\;a^*(-4.88)\;and\;b^*$(59.25).