• The Journal of Advanced Prosthodontics
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• v.8 no.1
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• pp.37-42
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• 2016

PURPOSE. This study investigated the effect of amount of thickness reduction on color and translucency of dental monolithic zirconia ceramics. MATERIALS AND METHODS. One-hundred sixty-five monolithic zirconia specimens ($16.3mm{\times}16.3mm{\times}2.0mm$) were divided into 5 groups (Group I to V) according to the number of A2-coloring liquid applications. Each group was then divided into 11 subgroups by reducing the thickness up to 1.0 mm in 0.1-mm increments (Subgroup 0 to 10, n=3). Colors and spectral distributions were measured according to CIELAB on a reflection spectrophotometer. All measurements were performed on five different areas of each specimen. Color difference (${\Delta}E^*{^_{ab}}$) and translucency parameter (TP) were calculated. Data were analyzed using one-way ANOVA and multiple comparison $Scheff{\acute{e}}$ test (${\alpha}=.05$). RESULTS. There were significant differences in CIE $L^*$ between Subgroup 0 and other subgroups in all groups. CIE $a^*$ increased (0.52<$R^2$<0.73), while CIE $b^*$ decreased (0.00<$R^2$<0.74) in all groups with increasing thickness reduction. Perceptible color differences (${\Delta}E^*{^_{ab}}$>3.7) were obtained between Subgroup 0 and other subgroups. TP values generally increased as the thickness reduction increased in all groups ($R^2$>0.89, P<.001). CONCLUSION. Increasing thickness reduction reduces lightness and increases a reddish, bluish appearance, and translucency of monolithic zirconia ceramics.

• The Journal of Advanced Prosthodontics
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• v.16 no.3
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• pp.174-188
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• 2024

PURPOSE. The purpose of this study was to investigate the effects of surface treatments, liquids, and aging on color, translucency, and surface properties of monolithic ceramics. MATERIALS AND METHODS. Lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) ceramics (n = 135 each) were cut and divided into three groups [crystallization+glaze (single stage), crystallization-glaze (two stages), and crystallization-polish (two stages)]. One sample from each group was examined using scanning electron microscopy (SEM). Remaining samples were divided into four subgroups (distilled water, coffee, grape juice, and smoothie) (n = 11 each), stored for 12 d in the respective liquids, and thermally aged. One sample from each subgroup was analyzed using SEM. The color, gloss, and roughness values of the samples were analyzed after surface treatment (initial) and storage under different liquids+aging conditions. The initial data and both the aged data and data change values were analyzed using robust two- and three-way analyses of variance. RESULTS. The glazed groups exhibited smoother surfaces. Ceramic type and ceramic-surface treatment interactions affected the initial translucency parameter (TP) (P < .001) and the initial and aged roughness values (P ≤ .001). Surface treatment type affected the color change (P < .001), and ceramic type affected the aged TP values (P < .001). Type of ceramic, surface treatment, and their interactions affected both the initial and aged gloss (P ≤ .001) and TP change values (P ≤ .015). Surface treatment type and ceramic-surface treatment interactions affected the gloss change values (P ≤ .001). CONCLUSION. Although both ceramics and all surface treatments are clinically applicable, crystallization-glaze is recommended. When gloss and smoothness are important or when translucency is important, ZLS or LDS may be preferred, respectively.

• Proceedings of the ESK Conference
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• 1996.04a
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• pp.264-269
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• 1996

Facial expression is innate communication skill of human. Human can recognize theri psychological state by facial parameters which contain surface movement, color, humidity and etc. This study is to quantify or qualify human emotion by measurement of facial electromyography (EMG) and facial movement. The measurement is taken at the facial area of frontalis and zygomaticus The results is indicative to discriminate the positive and negative respond of emotion and to extract the parameter sensitive to positive and negative facial-expression. The facial movement according to EMG shows the possibility of non-invasive technique of human emotion.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.218-226
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• 2018

PURPOSE. The aim of this study was to define a color space of non-vital teeth and to compare it with the color space of matched vital teeth, recorded in the same patients. MATERIALS AND METHODS. In a group of 218 patients, with the age range from 17 to 70, the middle third of the buccal surface of 359 devitalized teeth was measured using a clinical spectrophotometer (Vita Easyshade Advance). Lightness ($L^*$), chromatic parameters ($a^*$, $b^*$), chroma ($C^*$), hue angle (h) and the closest Vita shade in Classical and 3D Master codifications were recorded. For each patient, the same data were recorded in a vital reference tooth. The measurements were performed by the same operator with the same spectrophotometer, using a standardized protocol for color evaluation. RESULTS. The color coordinates of non-vital teeth varied as follows: lightness $L^*$: 52.83-92.93, $C^*$: 8.23-58.90, h: 51.20-101.53, $a^*$: -2.53-24.80, $b^*$: 8.10-53.43. For the reference vital teeth, the ranges of color parameters were: $L^*$: 60.90-97.16, $C^*$: 8.43-39.23, h: 75.30-101.13, $a^*$: -2.36-9.60, $b^*$: 8.36-39.23. The color differences between vital and non-vital teeth depended on tooth group, but not on patient age. CONCLUSION. Non-vital teeth had a wider color space than vital ones. Non-vital teeth were darker (decreased lightness), more saturated (increased chroma), and with an increased range of the hue interval. An increased tendency towards positive values on the $a^*$ and $b^*$ axes suggested redder and yellower non-vital teeth compared to vital ones.

• The Journal of Internal Korean Medicine
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• v.34 no.1
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• pp.71-85
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• 2013

Objectives : The aim of this study was to evaluate the distribution of tongue color and the correlation of the tongue colors with clinical laboratory parameters. Methods : Statistical analysis on the frequency of each tongue color and the results of the clinical laboratory parameters in each tongue color group. Results : Tongue colors that appeared most frequently were 702c, 695c, 493c, 694c, 701c, 500c, 7432c, 7431c, 7634c, 7419c in that order. Following them, 494c and 507c were rarer colors, and 501c, 673c, 687c, 693c, 696c, 703c, 7418c were equally rarest colors. Among each tongue color group, a significant difference was found in the result of complete blood cell count (CBC). The level of red blood cell (RBC) of 7432c group was significantly higher than that of the other groups except 694c group. The level of hemoglobin (Hb), hematocrit (Hct) of 7432c group were significantly higher than those of all the other groups. The level of RBC of 7431c group was lowest and significantly different from 694c, 7432c group. In results of the other tests were not significantly different. However the level of total cholesterol was higher in 695c, 694c, 500c group, and the level of triglyceride was higher in 500c, 7431c, 694c group. Those four colors have a low chroma and 7431c, 695c take blue violet color. Conclusions : The tongue color is distributed throughout following colors by order of frequency: 702c, 695c, 493c, 694c, 701c, 500c, 7432c, 7431c, 7634c, 7419c, 708c, 494c, 507c, 501c, 673c, 687c, 693c, 696c, 703c, 7418c. Some parameters of CBC has a significant correlation with some tongue colors. Other results including lipid profile, renal function test, and liver function test had no significant difference according to tongue color. However, the colors which have low chroma or take blue violet color tented to be higher in the levels of total cholesterol and triglyceride.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.173-181
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• 2003

Physicochemical changes in corn starch caused by irradiation were investigated, and irradiated samples were identified. Viscosity, TBA value, Hunter color, and total viable count were measured after irradiation of corn starch. Corn starches from Korea and China were irradiated at 0, 2.5, 5, 7.5, 10, and 15 kGy using a $Co^{60}$ irradiator and stored for 9 months at $0^{\circ}C$ and $20^{\circ}C$. Viscosity and specific parameter values decreased in all samples with increasing irradiation dosage at 50 rpm, showing a dose-dependent relationship $(above\;R^2=0.80)$ between non-irradiated and irradiated samples during storage. These results suggest that detection of irradiated corn starches is possible using viscometric method during storage. Total viable count, TBA value, and Hunter color were determined as supplemental indices for measuring viscosities of samples. Total viable count and TBA values showed dose-dependent relationship $(2.5{\sim}15 kGy)$. Differences in viscosity and total viable count, and TBA values among non-irradiated samples showed little changes with the lapse of post-irradiation time, but were still distinguishable for more than 6 months at $0^{\circ}C$ and $20^{\circ}C$ for corn starches from korea and China.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1235-1243
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• 2021

Geostationary Ocean Color Imager 2 (GOCI-II) on Geo-KOMPSAT-2 (GK2B)satellite was developed as a mission successor of GOCI on COMS which had been operated for around 10 years since launch in 2010 to observe and monitor ocean color around Korean peninsula. GOCI-II on GK2B was successfully launched in February of 2020 to continue for detection, monitoring, quantification, and prediction of short/long term changes of coastal ocean environment for marine science research and application purpose. GOCI-II had already finished IAC and IOT including early in-orbit calibration and had been handed over to NOSC (National Ocean Satellite Center) in KHOA (Korea Hydrographic and Oceanographic Agency). Radiometric calibration was periodically conducted using on-board solar calibration system in GOCI-II. The final calibrated gain and offset were applied and validated during IOT. And three video parameter sets for one day and 12 video parameter sets for a year was selected and transferred to NOSC for normal operation. Star measurement-based INR (Image Navigation and Registration) navigation filtering and landmark measurement-based image geometric correction were applied to meet the all INR requirements. The GOCI2 INR software was validated through INR IOT. In this paper, status and results of IOT, radiometric calibration and INR of GOCI-II are analysed and described.

• The Journal of Advanced Prosthodontics
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• v.15 no.5
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• pp.238-247
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• 2023

PURPOSE. The purpose of this study was to assess the effect of resin cement shade on the color of different novel ultratranslucent monolithic zirconia and lithium disilicate veneer materials. MATERIALS AND METHODS. For a total of 40 specimens, flat cylindrical discs with a 9-mm diameter and 0.5-mm thickness were created using CAD/CAM technology. The specimens were divided into five groups according to their material (n = 8) (e.max, Prettau, Aidite, Shofu and Dima) using A1 shade. Resin discs with the same diameter and shade as the specimens served as tooth-colored substructures. Three shades (neutral, light and warm) of resin cement try-in pastes (Variolink Esthetic LC) were used as the luting cement material. The color of each material group was measured before and after cementation using the three cement shades, and the CIE L^*a^*b^* coordinates were obtained with a spectrophotometer. Values for the translucency parameter (TP) and color change delta E (E) before (baseline) and after cementation of each specimen were determined. To compare differences among the material groups within each shade of cement and among various shades of cement within each material, the data were analyzed using one-way ANOVA and post hoc testing. RESULTS. Color coordinates L^*, a^* and b^* significantly changed after the application of try-in pastes relative to baseline values, with a noticeable decrease in lightness (L^*) (P < .05). A significant color change (ΔE) was observed in all tested materials after cementation, with ΔE values exceeding 3.3 (P < .05). Although TP changed after cementation for most materials tested, these changes were not statistically significant (P > .05). Shofu and Dima ceramics showed the lowest TP values, while Aidite and Prettau showed the highest TP values. For e.max, translucency decreased after cementation with neutral and warm shades, and it significantly increased after cementation with a light shade. CONCLUSION. The shade of cement significantly altered the final color of the ceramic veneer material to a level above the threshold at which the clinical perception of color change occurred (> 3.3). The TP was not influenced by the cement shade. The translucency levels of the novel ultratranslucent multilayer monolithic zirconia ceramics Aidite and Prettau were higher than that of the lithium disilicate e.max material.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.68-74
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• 2006

To utilize sea tangle single cell detritus (SCD) as food additive, SCD noodle was developed using mixture model. Flour improved, whereas water decreased texture of SCD noodles. Texture of SCD noodle decreased initially and then increased as SCD content increased. Flour and SCD increased, whereas water decreased $L^*$ and $b^*$ values of dried and cooked noodles. Flour decreased $a^*$ values of dried and cooked noodles, while SCD increased $a^*$ value of cooked noodle. Response constraint coefficient showed SCD influence on texture, and $L^*$ and $b^*$ values of dried and cooked noodles was higher than those of flour and water, whereas water influence on $a^*$ value was higher than those of flour and SCD. Texture and color values fitted nonlinear model with interaction terms for flour-water, flour-SCD, and water-SCD. Optimum mixing ratio value of flour : water : SCD was 63.3 : 31.0 : 3.7%. Sensory evaluation value of SCD noodles was lower than those of industrial and electrolyzed SCD noodles.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.649-654
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• 1989

The color distribution of fish sauces was studied by using the change in log absorbance per 100nm as a parameter of color tone. A linear relationship was found between the logarithm of absorbance (log A) and wavelength at 450 nm to 650 nm in the color of fish sauces. Change in log A per 100nm $({\Delta}A)$ in the color of the fish sauce products was in the range of 0.55 to 0.59. Absorbance at 450 nm (A 450) of the fish sauce treated with soy sauce koji was high in comparison with A 450 of the fish sauce treated by pronase and control. The color of fish sauces treated with soy sauce koji was dark reddish orange, and was similar to the color of soy sauce. A 450 of every fish sauce increased with the progress of fermentation but ${\Delta}A$of the fish sauces slightly increased at the beginning of fermentation and then decreased at the end of fermentation. In the results of sensory evaluation for the flavor of fish sauce products, the fish sauce product treated with soy sauce koji that 20% salt was added at the first stage was the molt desirable in the strength of flavor, tastefulness and after taste, and the fish sauce was also the best in acceptability.