• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.9
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• pp.769-774
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• 2016

Epoxy polymer exposed to solar radiation on long-term is required to a long-term environmental test in order to ensure the reliability of operation performance. In this paper, the solar aging experiment is performed for 7, 14, 28, 56, and 84 cycles, using solar simulator designed according to MIL-STD-810. After the aging experiment, measuring RGB values and using the CIE1976 color space, each RGB decreasing rates and total color shift are calculated. In addition, using a universal testing machine, mechnical properties according to ASTM-D638 are measured. As a result, by increasing solar aging period, total color shift is increased, and the tensile strength and elongation are decreased, but the elastic modulus and the poisson's ratio are slightly changed.

• Restorative Dentistry and Endodontics
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• v.28 no.3
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• pp.195-202
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• 2003

The purpose of this study was to evaluate the color changes of the composite resin resulting from xenon lamp exposure in different environments. Composite resin (Z 250 ; shade Al, A2, A3, A3.5, and A4) were applied in a cylindrical metal mold. Seventy five specimens according to environments of exposure were made as follows; Group I aluminum foiling of the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group II : exposure of xenon lamp to the specimens in the air at $37^{\circ}C$ for 1 day and 7 days. Group III: exposure of xenon lamp to the specimens in distilled water at $37^{\circ}C$ for 1 day and 7 days. The color characteristics ($L^{*},a^{*},b^{*}$) of the specimens before and after exposure of xenon lamp were measured by spectrophotometer and the total color differences (${\Delta}E^{*}$) were computed. The results obtained were as follows : 1. In all groups except A1 shade of group III, the ${\Delta}E^{*}$ values presented below 2.0, and group III showed the highest ${\Delta}E^{*}$ values followed by group II and group I in a decreasing order(p<0.05). 2 In all shades and groups, the more the exposure time of xenon lamp and the lighter the shade were, the higher the tendency for discoloration (p<0.05). 3. The composite resins which was exposed to xenon lamp in the distilled water was more discolored than those in the air (p<0.05). 4. The major changes of composite resins which were exposed to xenon lamp in the air were an increase in yellowness through a positive shift of the $b^{*}$ value, and those in the distilled water were an increase in darkness and yellowness through a negative shift of the $L^{*}$ value and a positive shift of the $b^{*}$ value.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.215-222
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• 2013

Bovine coat color is decided by the melanocortin receptor 1 (MC1R) genotype mutation and melanogenesis. Specially, in the various cattle breeds, dominant black coat color is expressed by dominant genotype of $E^D$, red or brown is expressed in the frame shift mutation of recessive homozygous e by base pair deletion and wild type of $E^+$ is expressed in various coat colors. However, not very well known about the effected of MC1R genotype mutation on the coat color through family lines in KBC. Therefore, this study were to investigate effect of MC1R genotype mutation on the coat color, and to suggest mating breed system in accordance with of MC1R genotype for increased on brindle coat color appearance. Parents (sire 2 heads and dam 3 heads) and offspring (total : 54 heads) from crossbreeding in KBC family line with the MC1R genotype and phenotype records were selected as experimental animals. The relationship between melanocortin 1 receptor (MC1R) genotypes expression verified by PCR-RFLP, and brindle coat color appearance to the family line of the cross mating breed from MC1R genotype pattern was determined. As a result, 4MC1R genetic variations, $E^+/E^+$ (sire 1), $E^+/e$ (sire 2 and dam 3), $E^+/e$ with 4 bands of 174, 207 and 328 bp (dam 1) and $E^+/e$ with 3 bands of 174, 207, 328 and 535 bp (dam 2) from parents (sire and dam) of KBC. However, 3 genetic variations, e/e (24%), $E^+/E^+$ (22%) and $E^+/e$ (56%) were identified in offspring. Also, brindle coat color expressrated was the e/e with the 0%, $E^+/E^+$ with 67% and $E^+/e$ with 77% from MC1R genotype in offspring on the cross mating of KBC. Furthermore, when the sire had $E^+/e$ genotype and the dam had $E^+/E^+$ with the 3 bands or $E^+/e$ genotype, and both had whole body-brindle coat color, 62% of the offspring had whole body-brindle coat color. Therefore, the seresults, the mating system from MC1R genotype patterns of the sires ($E^+/e$) and dams ($E^+/E^+$ with the 3 bands or $E^+/e$) with brindle coat color may have the highest whole body-brindle coat color expression in their offspring.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.736-742
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• 2009

This study was conducted to investigate the effect of various high pressure freezing and thawing treatments on the physical properties of pork. To compare the effects of the freezing and thawing process on meat quality, atmospheric freezing followed by running water thawing (AFRT), pressure shift freezing followed by running water thawing (SFRT), and pressure shift freezing and pressure assisted thawing (SFAT) were conducted at pressure of 250 MPa and cooling temperature of $-22^{\circ}C$. SAFT and SFRT showed a shorter phase transition time and total thawing time than AFRT. The pH value of treated samples increased significantly (p<0.05) compared to unfrozen meat. In addition, SFAT and SFRT showed a higher pHvalue than AFRT. Although the water holding capacity was significantly decreased (p<0.05) for SFAT and SFRT, SFRT reduced drip loss. In regards to color, SFAT and SFRT resulted in a significant increase in color parameters (p<0.05) relative to AFRT, while SFAT produced a higher L*-value. High pressure treatment significantly increased shear force (p<0.05) compared to AFRT, and, where SFRT showed the highest shear force. Therefore, these combined results indicated that the hydrostatic pressure treatment improved the functional properties of pork and increased the freezing and thawing rate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.949-956
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• 2016

There are a number of effects by solar radiation in many aerospace industrial fields, such as degradation of mechanical properties, sealing effect of sealants or decolorization. Because it takes long time to investigate these effects by using the light of natural state, new methods are developed for accelerating this phenomenon. In this paper, we developed an apparatus to simulate accelerated solar radiation phenomenon selecting irradiation intensity $1,120W/m^2$ as the designed environment. Epoxy polymer as the composite material was chosen and processed by ASTM-D638, a reference for tensile test of polymer and plastic. Total color shift was selected as the test category to evaluate acceleration of the test. We obtained acceleration factors and numerical model from test data and concluded it can shorten test periods by accelerated irradiation intensity of $1,120W/m^2$.

• Ocean and Polar Research
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• v.40 no.3
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• pp.127-143
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• 2018

This study analyzed the influence of climate change on the spawning ground area of the common squid, Todarodes pacificus. To estimate long term changes in the area of the spawning ground of the common squid, water temperature at 50 m deep that can be inferred from sea surface temperature (SST) based on both NOAA/AVHRR (1981.07-2002.12) and MODIS/AQUA (2003.01-2009.12) ocean color data was analyzed. In addition, five climate indices, Arctic Oscillation Index (AO), Siberian High Index (SH), Aleutian Low Pressure Index (ALP), East Asia Winter Monsoon Index (EAWM) and Pacific Decadal Oscillation (PDO) which are the main indicators of climate changes in the northwestern Pacific were used to study the relationship between the magnitude of the estimated spawning ground and climate indices. The area of the estimated spawning ground was highly correlated with the total catch of common squid throughout four decades. The area of the estimated spawning ground was negatively correlated with SH and EAWM. Especially, PDO was negatively correlated with the area of the spawning ground in the northwestern Pacific (r = -0.39) and in the southern part of the East Sea (r = -0.38). There was a positive relationship between the AO and the area of the spawning ground in the northwestern Pacific (r = 0.46) as well as in the southern part of the East Sea (r = 0.32). Temporally, the area of the winter spawning ground in the southern part of the East Sea in the 1980s was smaller than those areas in the 1990s and 2000s, because the area was disconnected with the western coastal spawning ground of Japan in the 1980s, while the area had been made wider and more continuous from the Korea strait to the western coastal water of Honshu in the 1990s and 2000s.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.05a
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• pp.47-70
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• 2008

Cost efficiency is today the primary requirement in the paper and board industry. This has led therefore, to a greater preponderance of products with specifically designed functionality to take account of current industry needs. Continually increasing machine coating speeds together with these new coating colour components have put more emphasis on the importance of the correct rheology and water retention of the coating colours to achieve good runnability and end product quality. In the coating process, some penetration of the aqueous phase, to the base paper or board must occur to anchor the pre-coating to the base or the topcoat to the pre-coat. The aqueous phase acts as a vehicle not only for the binder, but also for the other components. If this water or material penetration is not controlled, there will be excessive material shift from the coating colour to the base, before immobilization of the coating colour will stop this migration. This can result in poor machine runnability, unstable system and uneven coating layer, impacting print quality. The performance of rheology modifiers or thickeners on the coating color have tended to be evaluated by the term, "water retention". This simple term is not sufficient to explain their performance changes during coating. In this paper we are introducing a new concept of "material retention", which takes note of the total composition of the coating colour material and therefore goes beyond the concept of only water retention. Controlled material retention leads to a more uniform z-directional distribution of coating colour components. The changes that can be made to z-directional uniformity will have positive effects on print quality as measured by surface strength, ink setting properties, print gloss, mottling tendency. Optical properties, such as light scattering, whiteness and light fastness delivery should also be improved. Additionally, controlled material retention minimizes changes to the coating colour with time in re-circulation giving less fluctuation in quality in the machine direction since it more closely resembles fresh coating for longer periods. Use of the material retention concept enables paper and board producers to have more stable runnability (i.e. lower process costs), improved end product quality (i.e. better performance of used chemicals) and/or optimized use of coating colour components (i.e. lower total formulation cost)

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1991-2001
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• 2009

This study provides basic information that is needed to build marketing strategies related to consumer brand-switching, through the investigation of consumer motivations for brand-switching, as determined by the types of fashion products. The study was implemented by a descriptive survey method using a questionnaire. The survey was conducted during the period of May $11^{th}$ through July $5^{th}$ 2008. A total of 184 completed responses were analyzed. All respondents were from the Seoul area and between the ages of 20 and 31. Factor analysis and Cronbach's alpha coefficients, one-way ANOVA and Duncan test were employed for the analysis of data. Significant differences were found in brand-switching motives according to the types of fashion products. For clothing, shift behavior occurred more often in conjunction with the attributes of the products itself, such as design, color, price, size, and fiber content. In general, clothes more than shoes, were likely subject to brand-switching most often on the basis of situational factors. On the other hand, for shoes, more brand-switching activities occurred because of non-product attributes, such as discounts, coupons, desire for a change, and wearing of friends. In light of the results, there is a need to differentiate brand related marketing strategies with respect to clothing and shoes. For clothing, efforts focusing on the improvement of the product attributes will be more effective in minimizing brand-switching. There is also a need to improve instructions for increasing the product understanding of salespersons as well as the ability to give advice in accordance with personal consumer characteristics. With regard to shoes, greater efforts should be given to promotional activities, and the desire of consumers for a change in order to prevent brand-switching of customers.