• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.146-154
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• 2008

This study was carried out for the purpose of obtaining the basic data for color identification of amethyst by spectrophotometer. For this, the eleven amethyst stone and one citrine stone from eight countries were prepared in facet cut or plate. The transmittance and reflection of this samples were investigated as a function of wavelength. The transmittance or reflection was transformed to tristimulus value (X, Y, Z) and chromaticity value (x, y, z) and then compared with the results of eye observation which was plotted on cm xyY color space. Finally, the influence of the amethyst's thickness on transmittance or reflection was investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.259-262
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• 2005

Image retention is a kind of fatal shortcoming of the AC PDPs for realizing high-quality picture. In this work, the measurement method of image retention was proposed using temporal measurement of luminance, CIEXYZ tristimulus values, IR emission of reset pulse, and temperaturel. On the base of temporal measurement of luminance, CIEXYZ tristimulus value, and IR emission of reset pulse, the retention time of Ne+5%Xe gas-mixture discharge was about 2 hours after white window image. However, it was about 20 minute on the base of temporal measurement of temperature.

• Journal of Korea Multimedia Society
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• v.18 no.9
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• pp.1027-1038
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• 2015

For last several decades, the color correction methods have been proposed for HDR(high dynamic range) images. However, color distortion problems take place after correcting the colors such as halos, dominant color as well known. Accordingly, this article presents a novel approach in which the method consists of tone-mapping method and cone response function. In the proposed method, the tone mapping method is used to improve the contrast in the given HDR image based on chromatic and achromatic based on the CIEXYZ tristimulus value, expressed in c/m². The cone response function is used to deal with mismatch between corrected image and displayed image as well as to estimate various human visual effects based on the CMCAT2000 color appearance model. The experimental results show that the proposed method yields better performance of color correction over the conventional method in subjective and quantitative quality, and color reproduction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.1
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• pp.25-30
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• 1982

To evaluate the quality of commercial dehydrated tea-products, the relationships between particle sizes, densities, moisture absorption & desorption and color appearance were studied by using Hunter-lab tristimulus colorimeter and spectrophotometer. Among the tea-products was held no significant relation between particle sizes and color appearance but red ginseng extract powder (RGEP) was included L, a and b values when was reduced particle size. appearance color of tea-products indicated red-orange color, L, a and b values were ranged 32.7 to 48.0, 4.0 to 10.0 and 5.6 to 18.0, respectively, densities of tea-products ranged 0.232 to 0.898 g/ml and increased L values, Hunter's a/b ratio values was included in 0.61 to 0.90. Color stability in this products was well agreed with decrease of total color difference value ($\Delta$E) and chromaticity difference value ($\Delta$C) of the Hunter-lab color data.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.769-781
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• 1997

The tristimulus values of 180 extracted maxillary and mandibular anterior teeth were measured by colorimeter. And it were colnverted to Munsell color order system(Hue, Value, Chroma) and CIE $L^*a^*b^*$ color coordinates. The commonly used Vita, and Bioform shade guides, 2 composite resin shade guides(Prisma APH and Z-100), and a glass-ionomer shade guide(Fuji II) were compared with these teeth. At the middle facial surface, color distributions of teeth were Hue(0.56YR to 9.77Y), Value(2.46 to 7.9), and Chroma(0.14 to 2.02). And the aberaged values and standard deviations for $L^*a^*b^*$ were $63.18{\pm}10.44$, $1.11{\pm}1.66$, and $5.79{\pm}2.36$. The shade guide did not match well with the color space of the human teeth. Especially, the lacks of the Yellow-red Hues and higher values were prominent. Compare with other measurements, the Hues of the teeth measured in this study were broadly distributed(most of ranges in Y and YR were included), while the Value and chroma were shown to the lower.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.12
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• pp.1405-1411
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• 2003

본 연구의 목적은 기계에 의한 객관적 오염제거 평가와 육안에 의한 주관적 오염제거 평가를 비교하기 위한 것이다. 본 연구를 위해 백색의 순면직물과 65%/35% 폴리에스테르/면직물 시료에 9가지의 오염을 각각 처리한 오염포를 제작한 후, 세탁 실험을 하였다. 주관적 오염제거의 평가는 오염시키지 않은 포를 기준시료로 하여 오염포와 같은 조건으로 세탁한 후, 오염제거도를 AATCC Gray Scale for Staining으로 평가하였다. 세탁 후 오염제거도를 객관적으로 평가하기 위해서 각 시료의 K/S values, CIELAB, CMC, ASTM E313 Whiteness Index(WI), ASTM E313 Yellowness Index, and CIE tristimulus values를 구하였고. 세탁에 의한 control 시료의 반사율 변화에 대한 오염포의 반사율 변화를 비교한 오염제거율(PSR)을 구하였다 육안에 의한 주관적 평가 결과와 기계에 의한 객관적 평가의 결과와의 관계를 파악하고자 상관분석을 실시하였다. 본 연구 결과, 주관적 평가와 객관적 평가사이에 유의적인 상관관계가 확인되었으며, 주관적 평가 결과 중 WI가 주관적 평가 결과와 가장 상관관계가 높았으며, PSR과 주관적 평가 결과와의 상관이 상대적으로 가장 낮은 것으로 나타났다. 따라서 백색포의 오염 판정이 필요한 산업체에서 현재 많이 사용하고있는 PSR보다는 WI나 다른 색차를 이용하여 객관적 오염 평가를 하는 것이 주관적인 오염평가 결과에 더 근접할 수 있음을 알 수 있었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.641-646
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• 1994

changes in HMF content, capsanthin content, Hunter tirstimulus values, color-preference, and pruchasing intent were investigated during storage of industry-produced kochujang packed with polyethylene and nylon complex film at 13, 27 and 37$^{\circ}C$. HMF content, which was very low at initial , did not showed significant increase during storage at 13$^{\circ}C$ for 180 days, but the accumulation of HMF was accelerated by higher temperature. Capsanthin content decreased more rapidly at higher temperature . L values decreased up to 60 days of storage and the storage temperature had little influence on the rate . But, after 60 days, L value decreased more slowly at 13 than at 27 and 37$^{\circ}C$ , a and b values showed linear decrease at 37$^{\circ}C$, but increase in a and b values at 13 and 27 $^{\circ}C$ during early storage was followed by decrease. ΔE decreased more rapidly at higher temperature . Color-preference and purchasing-intent for kochujang decreased during storage at 27 and 37 $^{\circ}C$, but did not show significant changes during storage at 13 $^{\circ}C$ for 180 days. L, and ΔE values of kochujang stored at 37 and 27Δ showed positive correlation with color-preference, but Hunter tristimulus values of Kochujang stored at 13$^{\circ}C$ did not show not any significant correlation with color preference.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.306-312
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• 2008

This study investigated the influence of pH on the color development of melanoidins formed from amino acid enantiomer model systems. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry. The browning and browning index showed no difference according to the type of amino acid enantiomers, while that formed from the D-Asn system was the only difference according to pH level. The tristimulus value of melanoidins formed from all model systems was located on a dominant wavelength of 475 nm, the blue zone of the diagram. In addition, the $L^*$, $a^*$, $b^*$, $C^*_{ab}$ values, and ${\Delta}E^*$ index on the basis of the type of amino acid enantiomers, the differences were markedly found at pH 4.0. At pH 7.0, significantly differences were found in the $L^*$, $a^*$, $b^*$ values, and ${\Delta}E^*$ index and not in the case of the lysine enantiomers. In addition, at pH 10.0, the differences were found in the $a^*$ and $b^*$ values from the lysine enantiomers and $C^*_{ab}$ value from the asparagine enantiomers. Therefore, the color development of melanoidins was influenced by the type of amino acid enantiomers and pH levels. Especially, it is thought that the $a^*$ and $b^*$ values can be used to explain the differences among the amino acid enantiomers in the color development of melanoidins.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.387-393
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• 1988

Changes in chemical composition, viscosity and color during fermentation of improved Kochoojang from four starch sources (wheat, barley, rice and glutinous rice) were examined. Analyses included measurements of moisture, reducing sugars, amino nitrogen, pH, total acidity, viscosity, color and sensory panel scores for viscosity, color, odor and taste. Changes in chemical composition were similar for all Kochoojang products. Decrease in viscosity was greatest during the first 10 days of fermentation. Hunter tristimulus values decreased gradually during fermentation, and total color difference after 60 days was greatest for rice flour Kochoojang. Sensory evaluation showed that the viscosity of rice flour Kochoojang was less desirable than that of the others. However, no significant differences were found in color, odor and taste of all Kochoojang products. A high negative correlation was observed between Hunter a value and visual preference.

• Journal of The Korean Association of Information Education
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• v.3 no.1
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• pp.134-142
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• 1999

The demand for recognizing the color as well as the object shape is increasing to use the detailed information, because-the expense of color input/output devices become cheap. The research on the color correction should be researched for the exact color presentation and color reproduction of color input/output systems. In this paper, we researched on the color correction of color scanner. The characterization of color scanner is a two step process of gray-balancing and color transformation. The decoupling of the gray-balancing from the color transformation enables the portability of the scanner characterization. We used the least square methods for the line fitting and the Neural Network for the storage space and computation speed. The output of Neural Network is similar to the target value in three-dimensional tristimulus space. The proposed color correction method can be used for all scanners of a manufacturer's model because of the portability.