• Progress in Superconductivity
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• 제14권1호
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• pp.30-33
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• 2012

We have grown $MgB_2$ superconducting thin films on the SiC buffer layers by means of hybrid physical-chemical vapor deposition (HPCVD) technique. Prior to that, SiC was first deposited on $Al_2O_3$ substrates at various temperatures from room temperature to $600^{\circ}C$ by using the pulsed laser deposition (PLD) method in a vacuum atmosphere of ${\sim}10^{-6}$ Torr pressure. All samples showed a high transition temperature of ~40 K. The grain boundaries of $MgB_2$ samples with SiC layer are greater in amount, compare to that of the pure $MgB_2$ samples. $MgB_2$ with SiC buffer layer samples show interesting change in the critical current density ($J_c$) values. Generally, at both 5 K and 20 K measurements, at lower magnetic field, all $MgB_2$ films deposited on SiC buffer layers have low $J_c$ values, but when they reach higher magnetic fields of nearly 3.5 Tesla, $J_c$ values are enhanced. $MgB_2$ film with SiC grown at $600^{\circ}C$ has the highest $J_c$ enhancement at higher magnetic fields, while all SiC buffer layer samples exhibit higher $J_c$ values than that of the pure $MgB_2$ films. A change in the grain boundary morphologies of $MgB_2$ films due to SiC buffer layer seems to be responsible for $J_c$ enhancements at high magnetic fields.

• 대한치과교정학회지
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• 제12권2호
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• pp.145-154
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• 1982

Plaster models were constructed and orthopantomographs were taken for 86 male and 70 female primary school pupils, whose upper and lower permanent 4 incisors and 1st molars were completely erupted without crowding; whose deciduous canines and molars were found almost uniformly even without any visible tooth fractures, dental caries or restorations on proximal surfaces of the teeth. Certain reference points on the orthophantomograph were set up and measured and the values were compared with actual or predicted values from the models. The following results were obtained: 1. In regards to available space, the values from the orthopantomograph were greater than the values from the models by a mean of 3.24% on the upper and 10.06% on the lower for males; 3.05% on the upper and 10.01% on the lower for females. 2. In regards to total mesiodistal widths of permanent canine, 1st and 2nd premolars, the values from the orthopantomograph were greater than the presumed values based on the size of lower permanent 4 incisors from the models by a mean of 18.50% on the upper and 24.09% on the lower for males; 14.54 on the upper and 20.51% on the lower for females. 3. Comparing the magnified values of total mesiodistal widths of permanent canine, 1st and 2nd premolars with those of available space, the regression constants of regression equation (Y = a + bX) between them were a=3.2336, b=0.6533 on the upper and a=5.0138, b=0.3290 on the lower for males; a=2.5994, b=0.6521 on the upper and a=3.0113, b=0.6586 on the lower for females. 4. The correlation coefficients between the magnified values of available space and permanent canine, 1st and 2nd premolars were moderately positive as 0.6474 in the upper and 0.505 on the lower for males; 0.6493 on the upper and 0.6183 on the lower for females. 5. In regards to magnified values of the available space from the orthopantomographs there were no significant difference between sexes, (P>0.05) but of the total mesiodistal widths of permanent canine, 1st and 2nd premolars, a significant difference between sexes was found.(p<0.01).

• The Journal of Advanced Prosthodontics
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• 제15권3호
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• pp.101-113
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• 2023

PURPOSE. This randomized controlled trial aimed to evaluate the effect of implants' two different diameters and cantilever lengths on the marginal bone loss and stability of mplants supporting maxillary prostheses. MATERIALS AND METHODS. Ninety-six implants were placed in sixteen completely edentulous maxillary ridges. Patients were randomly divided into two groups: Group A, implants were placed with a cantilever to anterior-posterior AP spread length (CL:AP) at a ratio of 1:3; Group B, implants were placed with a CL:AP at a ratio of 1:2. Patients were further divided into four sub-groups: Groups A1, A2, B1, and B2. Groups A1 and B1 received small diameter implants while Groups A2 and B2 received standard diameter implants. Bone height and stability measurements around each implant were performed at 0, 4, 8 and 24 months after definitive prostheses delivery. RESULTS. Statistical analysis of the mean implant stability and height values revealed an insignificant difference between Group A1 and Group A2 at all the different time intervals while significantly higher values in Group B1 in comparison with Group B2. Results also showed significantly higher values in Group A1 in comparison with Group B1 and an insignificant difference between Group A2 and Group B2 at all the different time intervals. CONCLUSION. It can be concluded that the use of small diameter implants placed with a CL:AP at a ratio of 1:3 provided predictable results and that the 1:2 CL:AP significantly induced more critical bone loss in the small diameter implants group, which can significantly reduce long term success and survival of implants

• 한국재료학회지
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• 제21권9호
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• pp.515-519
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• 2011

The purpose of this study was to determine the optimal firing condition and composition for $Al_2TiO_5$ crystal, which is suitable for stable coloration in glazes at high temperatures, using $Cr_2O_3$ as chromophore for the synthesis of $Al_2TiO_5$ system pigments. $Al_2TiO_5$ has a high refractive index and good solubility of chromophore in the $Al_2TiO_5$ lattice, making this structure a good candidate for the development of new ceramic pigments. Pigments were synthesized by using $Al_2O_3$ and $TiO_2$ mainly. Various amounts of $Cr_2O_3$ such as 0.01, 0.02, 0.03, 0.04 and 0.05 mole were also added. Each compound was synthesized at $1300^{\circ}C$, $1400^{\circ}C$, and $1500^{\circ}C$ for 2 hours and cooled naturally. The crystal structure, solubility limit, and color of the synthesized pigments were analyzed by XRD, SEM, Raman spectroscopy, UV and UV-vis. The changes in color as the result of applying 6 wt% of the synthesized pigments to lime barium glaze were expressed as CIE-L*a*b* values. A $Cr_2O_3$ 0.03 mole doped $Al_2TiO_5$ brown pigment was successfully synthesize at $1400^{\circ}C$, and the values of CIE-L*a*b* parameters were L* = 44.62, a* = 3.10, and b* = 17.25. In the case of the pigment synthesized at $1500^{\circ}C$, the brown color was obtained at 0.01 mole and 0.02 mole $Cr_2O_3$, and the CIE-L*a*b* values were 55.34, 1.73, 28.64, and 49.39, 0.51, 21.33, respectively. At $1500^{\circ}C$, the maximum limit of solid solution was 0.03 mole $Cr_2O_3$. The glazed sample showed green color, and the values of the CIEL* a*b* parameters were L* = 45.69, a* = -0.98, and b* = 20.38.

• 한국식품영양학회지
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• 제15권1호
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• pp.1-6
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• 2002

진공포장이 냉장 돈육의 지질산화 및 육색에 미치는 영향을 조사하기 위해 돈육의 등심부위를 진공포장한 후30일 동안4$^{\circ}C$에서 냉장저장하면서 저장기간에 따라 TBA가, PH, 홍색화 시간 및 CIE L$^{*}$ a$^{*}$ b$^{*}$ 값의 변화론 측정하였다. TBA가는 랩포장육의 경우 저장 7일 이후에 급격히 증가되었으나, 진공포장육은 저장 30일까지 낮은 수준으로 유지되었다. PH도 랩포장육의 경우 저장 7일 이후에 급격히 증가되었으나, 진공포장육은 저장말기까지 매우 완만하게 증가되었다. CIE a$_{*}$ 값과 반사도의 측정 결과 진공포장육의 홍색화 시간은 포장개봉 후 30분이었다. 따라서 진공포장 개봉 직후와 개봉 30분후에 CIE L$^{*}$ a$^{*}$ b$^{*}$ 값을 측정하여 랩포장육과 비교하였다. CIE L$_{*}$ 포장육의 경우 저장 7일부터 급격히 감소되었으나, 진공포장육은 개봉 직후의 경우 저장말기까지 점차 증가되는 경향이 었으며, 개봉 30분후의 경우 개봉 직후보다 약간 높거나 큰 차이가 없었다. CIE a$_{*}$ 값은 랩포장육의 경우 저장 7일까지 점차 증가되었고 그 후 급격히 저하되었으나, 진공포장육은 개봉 직후의 경우 저장초기에는 랩포장육보다 매우 낮은 수준이었고, 저장기간이 경과 됨에 따라 점차 증가되었으며, 개봉 30분후의 경우 개봉 직후보다 전반적으로 높은 수준이었다. CIE b$_{*}$ 값은 랩포장육의 경우 저장 4일째에 크게 증가되었고 그 후 급격히 저하되었으나, 진공포장육은 개봉 직후의 경우 랩포장육보다 매우 낮은 수준이었고, 저장기간이 경과됨에 따라 완만하게 증가되는 경향이었으며, 개봉 30분후의 경우 개봉 직후보다 매우 높은 수준으로 유지되었다.

• 한국인쇄학회지
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• 제27권1호
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• pp.1-14
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• 2009

The color reproduction of digital still camera does not, in general, match those of the final output device. Because color gamut of these devices is different, it is therefore necessary to take account of a way to match. The way uses the optimized profile to output device an image. This paper proposed a way to create the input profile of digital still camera for standardization soft proofing process. The results of proposed way showed that for input profiles equivalent, good results relatively. In this paper, an experiment was done where the illumination sources used as the standard illumination 5200K and illuminated at a $45^{\circ}$ angle in the best illumination efficiently. The white balance was in mode 'custom' : aperture F11, exposure time 1/60s, ISO50, focal length 80mm. The images were exported and saved as 16bit RGB TIFF(AdobeRGB, sRGB, ProphotoRGB) images. To do the test, the RGB values of the RGB TIFF images are processed through the ICC input profile to arrive at processed $CIEL^*a^*b^*$ values. A profiling tool such as ProfileMaker 5.0 and Monacoprofile 4.8 are used to do this. The processed $CIEL^*a^*b^*$ values are compared to the reference $CIEL^*a^*b^*$ values and these two values are used to calculate a ${\Delta}E{^*}_{ab}$.

• 한국식품과학회지
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• 제17권6호
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• pp.426-430
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• 1985

자초(紫草)추출물의 외관상 변색에 영향을 주는 온도와 pH에 대해 조사하였다. 변색은 Hunter치(値)의 차이로 표시 할 수 있으며 자초추출물의 Hunter치(値)는 $50^{\circ}C$ 이상에서 변화하기 시작하고 $60^{\circ}C$ 이상에서는 온도와 상관관계를 이루었다. 온도에 따른 Hunter L, a, b, 치(値)의 변이상관계수는 열처리 시간이 증가함에 따라 감소하였으며, 전체변색의 상관계수는 증가하였다. 66.7% 에탄올로 추출한 추출물을 1시간 열처리 할때 Hunter치(値) 변이 상관계수는 L치(値)의 경우 -0.3696, a치(値)의 경우 -0.4124, b치(値)의 경우 -0.2279, 전체 변색에 있어선 0.5983이었다. 이 때 전체변색의 상관계수는 Hunter L, a, b 각각의 상관계수로부터 직접 계산할 수 있었으며 0.5988로서 거의 비슷한 값을 보여주었다. 한편 pH를 낮추면 Hunter a치(値)는 감도하고 L, b치(値)는 약간 증가하였으나 pH를 증가시키면 pH6.5를 전후로 해서 Hunter L, a, b 치(値) 모두 다 급격히 감소하여 외관상 색깔이 좋지 않았다. 자초(紫草)추출물은 pH가 4.0-6.5일 때 외관상 가장 좋은 '선명한 붉은색'을 나타내었다.

• 한국지역사회생활과학회지
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• 제17권4호
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• pp.39-48
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• 2006

This study was carried out to make a search for the usefulness of marigold plants (Tagetes erecta) as a natural dye. And we have also examined into the dyeability and antifungal activity of silk and cotton fabrics dyed with 2% powdered colorant and 1% liquid colorant. Almost surface colors of silk and cotton fabrics dyed with 2% powdered colorant and that dyed with 1% liquid colorant except for that treated Cu and Fe with mordants were shown by Y-level. $L^*$ values of silk fabrics dyed with 2% powdered colorant were 66.2 to 86.39, those $a^*$ values were -1.97 to 6.09, and those $b^*$ values were 13.69 to 35.97. And $L^*$ values of cotton fabrics dyed with 2% powdered colorant were 78.97 to 89.62, those a values were -3.39 to 0.38, and those $b^*$ values were 5.63 to 15.61 $L^*$ values of silk fabrics dyed with 1% liquid colorant were 34.37 to 85.57, those a values were -7.79 to 12.33, and those $b^*$ values were 15.13 to 82.91, And $L^*$ values of cotton fabrics dyed with 1% liquid colorant were 44.12 to 87.90, those $a^*$ values were -8.37 to 6.18, and those $b^*$ values were 11.65 to 78.87. Colorfastness of silk fabrics against light treated nothing with mordants and that dyed with 1% liquid colorant decreased for a little by second grade, however, that against washing, rubbing, perspiration and dry cleaning were increased over fourth grade. Colorfastness of cotton fabrics in terms of rubbing, light, and dry cleaning, except for washing and perspiration, were shown by over third grade, when that was treated nothing with mordants. Antifungal activities of silk fabrics treated nothing with mordants and dyed with 1% liquid colorant of marigold extracts were shown by 28.9% against Staphylococcus aureus. However, those of Al, Ca, Cu and tartaric acid mordanting were more than 25.5% against Staphylococcus aureus and Klebsiella pneumoniae.

• 한국정보통신학회논문지
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• 제13권6호
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• pp.1181-1187
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• 2009

본 논문에서는 퍼지 추론 기법을 이용하여 구름의 종류를 분석하는 방법을 제안한다. 본 논문에서는 가시 영상과 적외 영상을 대상으로 육지 영역은 RGB 컬러 정보 중에 G 채널 값의 수치가 높고, 바다 영역에서는 B 채널 값의 수치가 높다는 정보를 이용한다. 이 정보를 이용하여 육지 영역에서는 R과 B 채널 값을 적용하고, 바다 영역에서는 R과 G 채널 값을 적용한다. 가시 영상과 적외 영상에서 임계치를 적용하여 잡음(구름 이외의 영역)을 제거하고, 잡음을 제거한 영상에서 육지 영역과 바다 영역을 구분한 후, 각 R, G, B 채널 정보를 퍼지 기법에 적용하여 구름 영역을 판별한다. 그리고 가시 영상과 적외 영상에 모두 포함된 구름 영역에 대해서는 두 영상을 합성하여 구름을 판별한다. 제안된 기법을 구름 분류에 적용한 결과, 제안된 방법 이 기존의 양자화를 적용한 방법보다 구름의 분석 성능이 개선된 것을 확인하였다.

• 환경생물
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• 제36권4호
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• pp.620-625
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• 2018

김은 한국에서 가장 경제성이 높은 양식 해조류이다. 그러나 최근 김 양식장에서 발생하는 황백화 현상으로 인해 엽체의 변색과 탈락이 자주 유발되어 수산업에 큰 피해를 유발하고 있다. 이 연구는 영양염 부족에 의한 김 황백화를 간단하고 빠르게 평가할 수 있는 방법을 개발하기 위한 목적으로 수행되었다. 10일 동안 빈영양 해수에서 배양한 방사무늬김 엽체의 색도를 정량화하기 위해 색차계를 사용하였다. 색차계로 측정한 명도(L), 적색강도(a)와 노란색강도(b) 값들로 방사무늬김의 황백화를 평가하였다. 방사무늬김 엽체의 액포는 4일차부터 관측되었으며, 6일차부터 액포가 증대하였다. 색차계의 L, a와 b값은 배양시간에 따라 유의한 차이를 보였다. 명도(L)는 시간의 경과에 따라 어두움에서 점차 밝아졌다. 노란색강도 (b) 값은 시간에 따라 증가하였으나, 적색강도(a) 값은 감소하였다. 색차계의 a/b 비와 적색강도(a) 값은 방사무늬김의 색도 차이를 구분하는 주요한 요인이었다. 황백화된 방사무늬김은 명도 (L) 70 이상, 적색강도(a) 2.6 이하와 노란색강도(b) 15.0 이상의 정량적인 값으로 구분되었다. 이 연구결과 색차계는 김 황백화의 정도를 손쉽고 빠르게 진단할 수 있는 유용한 도구로 이용할 수 있음을 밝혔다.