• The Journal of Advanced Prosthodontics
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• v.6 no.4
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• pp.309-316
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• 2014

PURPOSE. The color of the ceramic restorations is affected by various factors such as brand, thickness of the layered the ceramic, condensation techniques, smoothness of surface, number of firings, firing temperature and thickness of dentin. The aim of this study was to evaluate the color change and surface roughness in dental porcelain with different thicknesses during repeated firings. MATERIALS AND METHODS. Disc-shaped (N=21) metal-ceramic samples (IPS Classic; Ivoclar Vivadent; Shaar, Liechtenstein) with different thickness were exposed to repeated firings. Color measurement of the samples was made using a colorimeter and profilometer was used to determine surface roughness. ANOVA and Tukey tests with repeated measurements were used for statistical analysis. RESULTS. The total thickness of the ceramics which is less than 2 mm significantly have detrimental effect on the surface properties and color of porcelains during firings (P<.05). CONCLUSION. Repeated firings have effects on the color change and surface roughness of the dental ceramics and should be avoided.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.3
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• pp.429-437
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• 1996

This paper surveys extraction condition-temperature, pH, and changes of adsorbance in accordance with extraction condition of curcuma Longa L. solution. Using extracted curcuma Longa L. Solution, dyeing behaviors with natural fiber, effect of mordants to color fastness and color change were investigated. It was found that the amount of absorption (K/S value) was increased by mordants (Fe, Cr) and mordants treatment affected color change of dyed fabric. Among the mordants, effect of citric acid to color change of dyed fabric was the smallest, and color difference of post- mordant treatment is smaller than that of pee-mordant treatment in making use of citric acid as mordant. And K/S value of post mordant was higher than that of pre mordant. It was found that the pre - and post- mordants treatment little affected color fastness, but affected the amound of adsorption and color change of dyed fabric.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.343-357
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• 1999

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600 hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smalt or color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order of non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light absorber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.

• Journal of The Korea Institute of Healthcare Architecture
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• v.29 no.3
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• pp.29-36
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• 2023

Purpose: The purpose of this study is to find out whether the color change of the LED light source has a significant effect on the beta wave activity of EEG in the learning state. Methods: The subjects of the experiment were 20 male and female college students between the ages of 19 and 25 who routinely perform their studies. In the created learning environment, the EEG change according to the change in the lighting color was measured while solving the Mensa thinking ability problem while sitting on a desk with LED lights installed on the top and a chair with a footrest to stabilize the legs. The light source consisted of 3 ready-made colors and 6 newly created colors. A total of 9 color light stimuli were given for 2 minutes each, and the EEG change of the subject was observed. After the experiment, the correlation was analyzed based on the mid-beta wave data recorded on the QEEG according to the color change of light and the Mensa problem score. Results: It was found that the activation of mid-beta waves was stimulated in the temporal lobes (T5, T3, T6, T4) and occipital lobes (O1, O2) of all subjects who focused on solving Mensa thinking problems. As a result of comparing the top 20% and the bottom 20% of problem solving scores, the upper group had no effect of lighting, while the lower group showed increased beta wave activity in response to color light stimulation in the order of T4, T6, and T5. Implications: It was confirmed that the color of light that activates the middle beta wave varies greatly depending on the subject's attention and learning ability, and it is judged that the color of light including the green wavelength is helpful in activating the middle beta wave in the group with low learning ability.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.2
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• pp.172-183
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• 2002

This study is going to compare the degree of color change which occurs in the following two cases of the factors which cause the color change of extra-staining, one is during glazing by the dental technician, the other is tooth brush abrasion which makes the biggest influence on color change. To compare the degree of color change before and after glazing, a sample was made with vintage incisal porcelain No. 59 OPAL(Shofu Inc, Japan), after that it was painted with three colors of porcelain stainers, then the degree of color was measured with a spectrophometer(Model Chromaview 300, Spectoron Tech Co. Korea) after it had been treated with firing only and glazing after firing 40,000-cycle and 80,000-cycle of tooth brush abrasion test were carried out in order to simulate the brushing effect of 4 years and 8 years by using the abrasion tester. The colors were measured before the test, and after the 40,000-cycle and 80.000-cycle operations and the surfaces were examined by SEM. The results of this study were as follows ; 1. The color change before and after glazing was not great enough to have a clinical significance but the orange color was changed more significantly statistically than the blue and light brown(p<0.05). 2. In the case of the color change of stained porcelain by tooth brushing, carrying out staining and glazing with two-times firings resulted in statically less color change than one firing only(p<0.05). 3. In the case of the difference in the stainer's color, the orange color which has higher chroma was statically more sensitive than the blue color(p<0.05) 4. In the case of the color change after the 80,000-cycle abrasion, all showed color change when there was one firing and the orange stainer showed some color change with clinical significance when firings were done two times.

• Journal of the Korea Fashion and Costume Design Association
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• v.7 no.2
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• pp.121-135
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• 2005

From a social psychological perspective, Make-up is an tool for run a lot smoother and perform communication efficiently. Many people give a turn to hair color through dyeing form due to yearning to change individual image through the image which the color is having. This paper study how make-up behavior, hair color and self-consciousness will affect the Level of Expected social-psychological effect of College Girl Students. In the sense of make-up behavior, according to result, a group of make-up behavior of self-satisfaction-oriented the level of expected social-psychological effect higher than a group of make-up behavior of tradition-oriented. Hair colors doesn't seem to be having much effect on the level of expected social- psychological effect, but have been shown to influence make-up behavior and self-consciousness. On the self-consciousness, a group of high self-consciousness the level of expected social-psychological effect higher than a group of low or fair self-consciousness. They doesn't have much effect passive expected effect as 'complement of self insufficiency' or 'a person consciousness' But they are affect active expected effect as 'the pleasure of change' and 'positive ascent'.

• Journal of the Korean Society of Costume
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• v.27
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• pp.121-132
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• 1996

This study showed the proper pigment extract in the Phe. Dyeing which is the basic dye of the natural plants dyeing,. Also it compared and examined the K/S the promotion of the color fastness and the effect of color difference change were attended by mordants and method of mordanting. 1. The most absorbance of Phellodendron. sol-ution is 330nm berberine is 430nm. 2. The best and proper temperature to extrat Phe,. was 80 and dyeing solution for 24 hours. 3. The pH effect was stable in the absorbances and color differences change. 4. Mordanted group increased the absorbances compared to non-mordanted sample. In case depth the most absorbance of Al. Sn. K. Cu and C. A solution were in 3% Fe and Cr were in 5%. In the color difference change they became dark reduced greenish and increased yellowish when their absorbances were in 3% 5. K./S was recoginzed by tainnin and fe, K/S was more increased pre-mordants than post-mordants. 6. Fe is the unchangable mordant in the color difference change and pre-mordants is more stable than post-mordants in the difference color. 7. Generally light C. F indicated more than grade 2 and light C. F, was much improved in post-mordanted by alumium potassium potass-ium dichromate. Washing C.F was improved in mordanted by tainnin and ferrous suulfate mordanted group was better than non-mordanted sample. Perspir-ation C,F was more stable in acid than alkali. Dry cleaning C.F indicated more than grade. 4.

• The Journal of Advanced Prosthodontics
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• v.12 no.3
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• pp.150-156
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• 2020

PURPOSE. The aim of this study was to evaluate the effect of different surface finishing processes on the color stabilities of lithium disilicate glass-ceramics, zirconia-reinforced lithium silicate ceramics, and resin nanoceramics after artificial ageing. MATERIALS AND METHODS. 216 samples were prepared from 3 different CAD/CAM materials (LAVA Ultimate, IPS e.max CAD, VITA Suprinity) with A1 HT color at a size of 14 × 12 mm and a thickness of 0.5 ± 0.05 mm. Color measurements of the samples were performed with a spectrophotometer using color parameters and CIE Lab color system on a gray backing between baseline color and after 5000 cycles of artificial ageing in 4 stages (i.e. the first measurement before the treatment, the second measurement after polishing, the third measurement after cement application, and the fourth measurement after artificial ageing). The results were evaluated using the Variance analysis and Fisher's LSD test. RESULTS. Resin nanoceramics (LU) exhibited higher color change values than zirconia-reinforced lithium silicate (VS) and lithium disilicate (EC) ceramics after artificial ageing. Manual polishing and glazing resulted in similar color change for LU and VS (P>.05). In the EC group, glazing provided statistically different results as compared to the manual polishing and control groups (P<.05). Among the ceramic groups, color change values of the subgroup, which was treated by glazing, of the zirconia-reinforced lithium silicate (VS) and lithium disilicate (EC) samples were below the clinically acceptable level (ΔE < 3.5). CONCLUSION. The lowest color change for all stages was observed in Vita Suprinity.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.81-86
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• 2009

The luminescence and fluorescence were investigated by photoluminescence spectroscopy for six gemstones which exhibit color change effect. The shape of luminescence peaks appears different when observed by a photoluminescence spectroscopewith a 514 nm Ar laser source. However, it was not possible to observe the difference in the spectra between the natural and synthetic origins for the same type of gemstones. It was found that the photoluminescence spectrum was related to the crystal structure of the stones. Photoluminescence spectra using a 325 nm He-Cd source reveal that fluorescence is relatively strong for synthetic alexandrite, synthetic color change sapphire and natural alexandrite comparing to the rest of gemstones examined.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.7-16
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• 2010

In this paper, we propose an ambient light control method based on the difference of image frames in video. The proposed method is composed of three steps. 1) The first step is to extract a dominant color of a current frame. 2) The second step is to compute the amount of change and the representative color in the changed region using the difference image. 3) The third step is to make a new representative color. The difference image is created from two images transformed into the YUV color space. The summed color difference of each pixel is used for the amount of change. The new representative color is created by synthesizing the current color and the changed color in proportion to the amount of change. We compare the variations of the light effect according to time with and without the proposed method for the same video. The result shows that the new method generates more dynamic light effects.