• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.131-132
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• 2023

Recently, the construction industry has seen the emergence of interior and exterior finishes using ultra-high performance concrete (UHPC) and colored concrete products using precast concrete (PC). However, the excessive amount of pigment used for coloring reduces the strength of the concrete. There is a need to improve the durability and chromaticity of colored concrete, and further analytical studies on the properties of colored concrete are also required. Therefore, in this paper, colored ultra-high strength cement composites (C-UHSCC) containing red and green inorganic pigments were prepared, and the compressive strength and color of the specimens were measured according to the age, and the correlation between strength and color was analyzed by simple linear regression analysis using R² value. The results showed that the red color was highly correlated with L^* and a^*, and the green color was highly correlated with a^*. These results can be considered for various concrete formulations, but research is needed to suggest the optimal pigment mixing ratio for proper strength and color development.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.85-94
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• 2005

Display characterization, deriving the relationship between digital input values and the corresponding CIEXYZ tri-stimulus values, is important to reproduce the accurate color in color management system. The relationship can be estimated from the nine channel TRCs(tone response curves) and the result of this characterization method is better than that of using three channel TRCs. However, the inverse display characterization using nine channel TRCs cannot be directly inverted because the CIEXYZ values corresponding to each of RGB values are inseparable. Accordingly, inverse display characterization is usually implemented by the 3D-LUT (look-up table) method. Although the result of 3B-LUT is accurate, creating the 3D-LUT requires a lot of memory space and considerable amount of measurements. Therefore the inverse characterization method is proposed based on the modeling of channel-dependent values and nine channel inverse process based on the GOG(gain, offset gamma) model. The proposed method enhances the accuracy of display characterization and reduces the complexity and the number of measurements data required for accuracy in 3-D LUT.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.76-83
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• 2000

This paper proposes a new color halftorning method using color correction by vector error diffusion to reduce color difference, necessarily appears on cross-media color reproduction In order to predict output colors on each device, a neural system IS applied and mean prediction errors in device characterization for monitor and printer are defined to calculate the thresholds for color correction Thus, color difference between monitor and printer is compared per each pixel If color difference is larger than the predetermined mean prediction errors, the halftoned dots to the current pixel are rearranged by vector error diffusion The proposed method can reduce the smear artifact by selective vector error diffusion and decrease color difference on cross- media color reproduction by color correction.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.140-142
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• 2011

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2007.11a
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• pp.85-86
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• 2007

• Journal of the Korean institute of surface engineering
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• v.38 no.1
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• pp.44-48
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• 2005

We prepared nickel silicide layers from p-Si(l00)/SiO₂(2000 Å)/poly-Si(700 Å)/Ni(400 Å) structures, feasible for gates in MOSFETs, by annealing them from 500℃～900℃ for 30 minutes. We measured the color coordination in visible range, cross sectional micro-structure, and surface topology with annealing temperature by an UV-VIS-IR spectrometer, field effect scanning electron microscope(FE-SEM), and scanning probe micro-scope respectively. We conclude that we may identify the nickel silicide by color difference of 0.90 and predict the silicide process reliability by color coordination measurement. The nickel silicide layers showed similar thickness while the columnar grains size and surface roughness increased as annealing temperature increased.

• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.379-384
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• 2009

Zirconia is widely used for structural materials in machinery due to its superior properties, such as high strength, high hardness, and high toughness. Zirconia generally has ivory or white color. Therefore many studies are performed for diversification of zirconia color, in order to be widely uitilized for decoration and machine parts which need distincfive color. In this study, graphite is used to prevent structural defect, to maintain superior properties, and to develop black color of zirconia by impregnation method. As specimen was impregnated at $1600^{\circ}C$ for 2 h, bending strength is 1221 MPa, density is $6.01\;g/cm^3$, hardness is 10.1 GPa, absorption coefficient is 0%, transmittance is Fail, chromaticity is 54. The results indicate that black zirconia has enough properties to be adopted as mechanical parts. Optimum impregnation time is 2 h for various observations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.7
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• pp.528-533
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• 2013

We focused on the development of red azo colorants with high thermal stability and good solubility for LCD color filter in this research. For the synthesis of hybrid azo colorants, we used the couplers of aniline, naphthol and benzoimidazol functional group. The synthesized hybrid azo colorants were charaterized by using NMR, UV/visible spectroscopy, FT-IR, EA and TGA. They represented the maximum absorption wavelengths which are longer than 500 nm in UV/visible spectrum. So they were confirmed to be suitable for red colorants of LCD color filter. Azo compound (1a, 1b) with aniline functional group had good solubility in organic solvents such as acetone, methanol, chloroform and PGMEA. Moreover azo compounds (1c, 1d and 1e) with naphthol and benzoimidazolone functional group gave excellent thermal stability higher than $250^{\circ}C$ in TGA thermograms.

• Korean Journal of Metals and Materials
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• v.50 no.1
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• pp.23-27
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• 2012

The color of a natural diamond that contains nitrogen impurities can be enhanced by a high pressure high temperature (HPHT) treatment. Type IaAB diamond samples containing nitrogen impurities were executed by HPHT process of 5.6 Gpa, 10 min by varying the annealing temperature at 1600, 1650, and $1700^{\circ}C$. Property characterization was carried out using an optical microscope, FT-IR spectrometer, low-temperature PL spectrometer, and micro Raman spectrometer. By observing optical micrographs, it can be seen that diamond sample began to alter its color to vivid yellow at $1700^{\circ}C$. In the FT-IR spectrum, there were no Type changes of the diamond samples. However, amber centers leading to brown colors lessened after $1700^{\circ}C$ annealing. In the PL spectrum, all the H4 centers became extinct, while there were no changes of yellow color center H3 before or after treatment. In the Raman spectrum, no graphite spots were detected. Consequently, diamond color enhancement can be done by higher than $1700^{\circ}C$ HPHT annealing at 5.6 GPa-10 min.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1049-1055
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• 2023

The purpose of this study was to investigate the association of twinkling artifacts according to the types of urinary stones in color Doppler ultrasound. For two types of urinary stones with different colors, the degree of occurrence of color Doppler twinkling artifact in water tank was analyzed, and the surface condition and composition of the stones were analyzed. The composition of Calcium and phosphorus were the most frequent components in white and brown stones excluding carbon and oxygen. Twinkling artifacts of color Doppler appear stronger in brown stone. The higher the phosphorus content of the stones, the shorter the twinkling artifact appears, so it is possible to predict the main composition of stones.