• Communications of the Korean Mathematical Society
• /
• v.39 no.2
• /
• pp.345-352
• /
• 2024

We introduce a new class of bi-partition function c_k(n), which counts the number of bi-color partitions of n in which the second color only appears at the parts that are multiples of k. We consider two partitions to be the same if they can be obtained by switching the color of parts that are congruent to zero modulo k. We show that the generating function for c_k(n) involves the partial theta function and obtain the following congruences: c₂(27n + 26) ≡ 0 (mod 3) and c₃(4n + 2) ≡ 0 (mod 2).

• The Journal of Advanced Prosthodontics
• /
• v.13 no.1
• /
• pp.1-11
• /
• 2021

PURPOSE. The study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment. MATERIALS AND METHODS. Four hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test. RESULTS. The maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)]. CONCLUSION. The comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.

• Journal of Conservation Science
• /
• v.33 no.6
• /
• pp.553-564
• /
• 2017

This report compared and analyzed the degree of surface change and results of a deterioration experiment to assess the possibility of using Dobak glue as an adhesive in the fossilizing treatment of the paint layer in earthen mural paintings. The weathering experiments were performed with a color-difference meter (CR-400, MINOLTA). After the experiment, Cinnabar 3% specimens, which exhibited diverse changes in the durability test, were additionally tested with a reflection-transmission device (CARY-5000, AGILENT). Post UV degradation, most of the Dobak-glue samples exhibited lesser color change than animal-glue samples, and after moisture absorption and drying, the 0.5% and 3% Dobak samples displayed a lower degree of change in the value of color difference. Furthermore, results of the reflection-transmission test after deterioration indicated that Dobak glue presented a lesser color change than animal glue. Therefore, if Dobak glue is used as a consolidating agent, discoloration on account of degradation is minimal.

• Fashion & Textile Research Journal
• /
• v.13 no.6
• /
• pp.972-982
• /
• 2011

The purpose of this study is to improve the method of color developing with alkali solution as a promotor of color developing for feasible use. Cotton fabric was dyed with persimmon extract ranged with 0~3% alkali component with 5 types of strong to mild alkali solution. Heat treatment for color developing was applied to fabric dyed with persimmon extract and alkali mixing solution. Tests were carried out to analyze the change of surface color, ${\Delta},Ea^*b^*$, and water repellent of the dyed cotton fabric. The alkali mixing sample showed higher ${\Delta},Ea^*b^*$ value than control one without alkali mixing on the base of dyed fabric due to high color developing by alkali in the initial step of dyeing process. As alkali concentration increased, deeper dark color appeared on the fabric. The fabric color was changed to more dark in the application of sodium hydroxide, sodium carbonate, potassium carbonate in the initial step of dyeing process but color was not changed by increased heating time. However, the fabric showed a slight dark color with sodium acetate and more color change than that of the fabric dyed with persimmon extract without alkali. Therefore, sodium acetate seemed to a suitable promotor for color developing in persimmon extract dyeing. Property of water repellent was showed after color developing by heating with low concentration of alkali treatment.

• The Journal of Korean Academy of Prosthodontics
• /
• v.42 no.2
• /
• pp.133-141
• /
• 2004

Statement of problem : Porcelain restorations are widely used in restorative dentistry with a high degree of general success. However, porcelain is brittle and may fracture intraorally. Sometimes a repair may be attempted using composite resin and bonding system available. Color stability of porcelain repair resins affects esthetics and prognosis of prosthesis, so that provides important criteria for the choice of porcelain repair resins. Purpose : The purpose of this study was to investigate the color stability of composite resins used widely as porcelain repair system. Materials and method : Composite resins used for this study were Carisma(Kulzer, Germany), Tetric ceram(Ivoclar, Liechtenstein), Filtek Z250(3M, USA), and Arabesk Top(VOCO, Germany). Thirty disc-shaped specimens($10{\times}2mm$) were fabricated from each composite resin. Color changes of specimens after treatment using thermocycling system(KD-TCS30, Kwang-duk F.A. Korea) and after immersion in methylene blue(0.05% by Wt) were measured with colorimeter(Model Tc-6Fx, Tokyo Denshoku Co.) and obtained data were analyzed. Results and Conclusion: The results obtained from this study were as fo11ows. 1. The color change of Filtek Z250 was lesser than those of Tetric ceram and Arabesk Top after thermocycling (12000 times). 2. All of the composite resins in this study showed increase of color change according to increase of thermocycling frequency. 3. After treatment with methylene blue, the color change of Arabesk Top was greater than those of Carisma and Tetric ceram, and Tetric ceram was more stable than others.

• Journal of the Korean Society of Costume
• /
• v.59 no.2
• /
• pp.1-17
• /
• 2009

This study is to understand the characteristics of Korean Women's Jeogories in modern times on the changes of its color and coloration over the time. The research was that the characteristics of the costumes produced in modern times ($1890{\sim}2000$) can be categorized into six periods according to the change of times. 1106 women's Jeogories were researched intensively in order to understand them, the conclusions are following: When the Chi-Square Test is applied to conduct cross analγsis of the said six periods divided on the basis of relevant theories, it is found that there is just partial difference in the hues in1890-1959 while there has been a big change in the hues of all Jeogories since 1960. It also seems that such a sudden change In hues took place till the end of the 1970s but there have been no significant difference and no distinct changes in hues sin[e the 1980s. As for color tones, high luminosity and low chroma hues were mainly used in all periods, but low luminosity and high chroma hues have been frequently used since the 1960s. It indicates that the long-used conventional and traditional colors gave way to various colors which were freely applied according to the tendency of individualism In the selection of colors as well. As for the coloration, one-color arrangement was predominant in white clothes while the combination of main color Y and supplementary rotor R was overwhelming in two-color arrangement. After the 1960s, not just the five major rotors but diverse colors, including bluish green, dark blue, were used, even varied patterns for linings.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.3
• /
• pp.65-74
• /
• 2009

Scene change detection is pretreatment to index and search video information in video search system, and it is very important technology for overall performance. Existing scene change detection used single characteristic of pixel value difference, histogram difference, etc or mixed single characteristics that have complementary relationship. However, accuracy of those researches is very poor for special video such as infrared camera, night shooting. Therefore, this paper is proposed the method that is mixed color histogram and at algorithm for scene change detection at the specific movie. To verify the usefulness of a proposed method, we did an experiment which used color histogram only and KLT algorithm with color histogram. In result, evaluation index of proposed method is improved about 11.4% at the specific movie.

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

• Journal of Fashion Business
• /
• v.11 no.1
• /
• pp.15-25
• /
• 2007

As a part of the study for the materials development of compound feelings, therefore, this study investigated into the effects of the colors of warp and weft on the overall colors of fabrics, along with the visual changes of colors by the measuring angle of both warp and weft, by means of cross-dyeing of cotton/PET union fabrics. First, the dyeing of cotton and PET fabrics individually with the same color, the dyeing of PET fabrics followed by that of cotton fabrics resulted in a small difference in color than the dyeing in the reversed order. Second, in the case of the dyeing of cotton/PET union fabrics with the color of one fiber fixed and that of the other in ten colors, the color of cotton fiber, which is warp, gave much influence. In addition, the color change was remarkable among complementary colors, while it was negligible among adjacent colors. Third, in the case of dyeing of cotton/PET union fabrics with the color of one fiber fixed and that of the other in ten colors, the results were different by the measuring angle. When PET was fixed in green and cotton was dyed in ten colors, color-deepening was observed by the inclination in the direction of warp and weft without the dominance over all colors like cotton. When cotton was dyed in red and PET in ten colors, the color of PET appeared dimly in the horizontal case by the direction of the light, and red appeared as inclined in the direction of warp and weft. This is because of the dominance of cotton color over the overall color, since the density of cotton fiber, the warp of union fabrics, is higher than that of PET, the weft. Thus, this is to be considered in the selection of the warp's color. In view of the above results, the color changes are outstanding when the color of warp dominates the overall color and when the colors of warp and weft are complementary, in comparison with the case when the colors are adjacent. The colors also change by the measuring angle.

• Korean Institute of Interior Design Journal
• /
• v.16 no.2 s.61
• /
• pp.295-302
• /
• 2007

The use of colors plays an important role in the field of space design. The selection of proper colors influences on people who use space by making the most of the psychological and physical functions of colors. Especially, the medical space is relatively more important than other indoor spaces in the selection of colors. The medical space has to be something to do with diversity and functions, and at the same time with stability and quietude, as well as the space with general convenient facilities. Color is not only related to the expression but also to the distinction of things and the existence. It also functions as a visual language. Human beings depend heavily on the function of color as a visual language. According to previous studies, human beings depend on color by 80% of the whole range of eyesight. Thus, color is an important factor in recognizing things and space. For example, in hospital, it Is very important to apply proper colors to various medical treatment spaces for the sake of patients' rest and healing. Various colors which do not consider the function of patients' rest and healing may make the space confusing against the change of space and structure. It is also important to apply colors to the change of space and structure. Another key point that I would like to make is that color has visual, direct and physical influence on the human body. For example, the color red with long wavelength serves to regulate body temperature. Research on the color scheme for hospitals should consider both physical and psychological factors. That is why the research should be carried out in depth through continuous clinical demonstration. The present research aims to outline color planning.