• Title/Summary/Keyword: chromatic change

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Application of UV-Vis Spectroscopic Analysis for Transformer Insulating Paper Degradation (UV-Vis 분광분석에 의한 전기변압기 내 절연지 열화도 측정)

  • Kong, Hosung;Han, Hung-Gu
    • Tribology and Lubricants
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    • v.35 no.3
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    • pp.151-157
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    • 2019
  • Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, $CO_2$ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.

Relationship between Reading Speed and Blinking Rate according to Longitudinal Chromatic Aberration during Book Reading (종이책 독서 시 종색수차에 따른 읽기속도와 순목횟수의 상관관계)

  • Kim, Se-il;Park, Mijung;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.369-375
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    • 2015
  • Purpose: The current study was performed to estimate the changes in reading speed and blinking rate according to different background colors when reading paper book and further investigate their correlation. Methods: Twenty-nine adults (10 males, 19 females) who consented to the present study and had no ocular disease, ocular surgery history showing normal binocular vision were participated into the study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min, respectively. Then, the reading speed per page and blinking rate per page were measured during reading and analyzed according to background colors. Results: Reading speed per page according to the background color showed a tendency to accelerate in the white and green background as the reading time increased however, it was almost unchanged in the blue background and rather decelerated in the red background. On the other hand, the blinking rate per page tended to decrease in all background as the reading time was increased however, the smallest reduction was shown in the red background. There was a correlation that the reading speed increased as the blinking rate decreased in all backgrounds and the best correlation was shown in the green background. Conclusions: From the results, a correlation between the increasing reading speed and the reducing blinking rate while reading paper book with same demand on accommodation and convergence was confirmed however, the change in blinking rate and reading speed was varied depending on the main wavelength of light. It might mean that the working speed and visual fatigue can be varied depending on the difference of main wavelength when doing near work. Thus, it can be suggested that the adjustment of working environment and conditions should be made according to the kind of required perception.

Change of Contrast Sensitivity Induced by Tinted Spectacle Lens (칼라필터 렌즈에 따른 대비감도의 변화)

  • Seo, Jae-Myoung
    • Journal of Korean Ophthalmic Optics Society
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    • v.21 no.1
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    • pp.47-51
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    • 2016
  • Purpose: The purpose of this study was to investigate the change of contrast sensitivity by prescribing tinted lenses and to provide the clinical manual. Methods: Contrast sensitivity was measured for twenty adults with normal vision while they wore yellow, orange and green tinted lenses. To measure contrast sensitivity, the 5 spatial frequencies (2, 4, 6, 8 and 10 cpd) were used for 33 ms and 233 ms, respectively. Results: The contrast sensitivity was overall higher with 233 ms than 33 ms (p<0.05). The peaks of contrast sensitivity with 33 ms and 233 ms were 1.75 log unit with the yellow lens and 1. 85 log unit without the color respectively. However, there was no significance between the yellow and orange tinted lens (p>0.64) Conclusions: Yellowish tinted lens that reduces chromatic aberration and the scattering is prescribed for the various purposes to improve visual functions. Before prescribing tinted lens, identifying characteristic of user and tinted lens for cut off wavelengths is recommended.

Stability Evaluation of Cleaning Agent for Ceramics (토기 및 도자기 유물에 사용되는 보존처리용 세척제의 안정성 평가)

  • Park, Daw-Woo;Kang, Hyun-Mi;Nam, Byeong-Jik;Jang, Sung-Yoon
    • Journal of Conservation Science
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    • v.25 no.4
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    • pp.451-464
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    • 2009
  • To do conservation for ceramics, sometimes it needs to clean the ceramics chemically to remove stains on the ceramics, which should be performed with caution. This study will provide quantitative data about the extraction characteristics of major elements from ceramics through the soaking test to evaluate the stability of ceramic cleaning agents. As soft textured pottery(fired at $700^{\circ}C$) had high absorption, it showed higher extraction characteristics in short soaking time. Especially the strong acid among chemical cleaning agents caused the expoliation and the color change on the surface of soft textured pottery. But these color change had no effect on the physical characteristics of soft textured pottery. The hard textured pottery(fired at $1,000^{\circ}C$) is relatively stable in the cleaning agent because it is ascertained the extraction of that was not enough and also it had little chromatic and physical change by strong acid. Porcelains(Celadon, Whiteware and Puncheong ware) was safer than the soft textured pottery due to their low extraction. But it should take precautions to clean the porcelains with lots of cracklewares such like Puncheong ware chemically in connection with the extraction characteristics and their cracklewares.

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A Study on the Role of -SO3- Ions in the Dehydration Limit of Poly(styrene-co-styrenesulfonic acid) Membrane

  • Ko, Kwang-Hwan;Kim, Joon-Seop;Lee, Chang Hoon
    • Elastomers and Composites
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    • v.52 no.3
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    • pp.180-186
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    • 2017
  • In this work, the effect of low-temperature dehydration of a poly(styrene-co-styrenesulfonic acid) (PSSA) membrane was investigated by differential scanning calorimetry, fourier transform infrared spectroscopy (FT-IR), electron magnetic resonancespectroscopy (EMR), and $^1H$- and $^{13}C$ solid-state nuclear magnetic resonance spectroscopy. These analyses were performed at room temperature for powdered PSSA specimens with and without dehydration and the following key observations were made. First, FT-IR analysis showed that low-temperature dehydration not only transformed the [${SO_3}^-{\cdots}H^+$] ionic pair in the non-hydrated PSSA to an $SO_3H$ group, but also induced the formation of -C=C- double bonds in the dehydrated PSSA. Second, the ${-SO_3}^{\bullet}$ radical was unambiguously identified by EMR spectroscopy. Third, H-abstraction was detected by $^1H$ magic-angle spinning spectroscopy. Finally, an unexpected color shift from white for the non-hydrated PSSA to a yellowish brown for the dehydrated sample was observed. In order to explain these experimental results, it was proposed that the formation of the intermediate hydrogen ($H^{\bullet}$) or hydroxyl radical ($HO^{\bullet}$) species was initiated by the dehydration process. The sespecies attacked the $SO_3H$ group and the tertiary proton at the ${\alpha}-carbon$, resulting in the formation of $-SO^{\bullet}$ radicals and -C=C- double bonds, which correlated with the color shift in the dehydrated PSSA sample. The semechanisms are useful for understanding the simultaneous loss of an aromatic ring and -SO- groups in the PSSA fuel cell membrane.

The Characteristics and Change of Colors on Fashion Collections in 1990s

  • Kim, Honey;Kim, Young-In
    • International Journal of Costume and Fashion
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    • v.7 no.2
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    • pp.18-31
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    • 2007
  • The purpose of this study is to examine color characteristics and color changes of the fashion collections through 1990s, and to provide the efficient color information for color planning upon fashion themes. For this research, a total of 30,084 colors were collected from Paris, Milan, London, New York Collections in 1990s. Those colors were first measured by the Pantone Textile Color Specifier and COS Color System and spectrophotometer(color eye 580). These measured color values $L^{\ast}a^{\ast}b^{\ast}$of CIE were converted into H V/C of Munsell System, and 12 tones of PCCS with 5 achromatic colors. The characteristics of collected colors were analyzed in general and by place, season and year. The results of the study are as follows : First, the hues of purple blue, yellow red, red, yellow and the tones of grayish, pale, white, black, dark grayish, dull, light grayish appeared mostly. Yellow was shown quite frequently in spring/summer while purple, purple blue, red and yellow red in fall/winter. White, pale, light, light grayish and light gray were shown more frequently in spring/summer while Black, dark grayish, grayish, dark gray and dark in fall/winter. Second, the characteristics of colors by 4 representative places were similar to the general characteristics of colors in 1990's. Third, There were distributed widely Red, Yellow Red, Yellow in the early 1990s, Green Yellow, Green, Blue Green in the mid of 1990s, and Purple Blue, Purple in the late of 1990s. The distribution range of chromatic colors showed wide in both of the early of 1990s and the mid of 1990s for a while, and achromatic colors of grayish, gray and black appeared mostly in the late of 1900s.

Characterization and Color Reproduction Based on Average Picture Level if PDP Displays (평균화면밝기에 기반한 PDP 디스플레이의 특성화 및 색 재현)

  • Kwon, Oh-Seol;Ko, Kyung-Woo;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.5
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    • pp.9-17
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    • 2008
  • This paper proposes a method of color reproduction considering the viewing conditions of a PDP TV. Because of a change of peripheral environments by a temporal and spatial location of observers, the ambient lightings should be considered in the process of color reproduction of displays. A conventional method enhances the contrast and saturation of images by controlling voltage gains in each channel, so that there is a limit to implementing the phenomenon of human adaptation. This method also faces difficulties in reproducing the perceived colors under a variety of viewing conditions. Accordingly, in order to solve this problem, we first characterize the device by considering the brightness and the flare effect. The chromatic adaptation is finally applied to reproduce colors in a PDP TV using the information from the viewing conditions by the sensor. The images reproduced by the proposed method are visually more superior to those reproduced by a conventional method in the experiments.

Induction of Optimal Condition of 40 Gbps RZ Format for OTDM/WDM Transmission (OTDM/WDM 전송을 위한 40 Gbps RZ 형식의 최적 조건 도출)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.14 no.6
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    • pp.831-837
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    • 2010
  • Optimal conditions of 40 Gbps RZ format for implementation of optical time division multiplexing/wavelength division multiplexing (OTDM/WDM) transmission system are induced by analyzing and comparing performance depending on duty cycle and extinction ratio (ER). Optical phase conjugator (OPC) and inline dispersion management (DM) are applied into optical transmission links for compensating signal distortion due to chromatic dispersion and nonlinearity of fiber. It is confirmed that RZ format of 0.25 duty cycle is less effected by system performance change depending on ER and it is suitable for multiplexing to 160 Gbps signal through OTDM. Also, it is shown that performance improvement of RZ format determined by same net residual dispersion (NRD) is more increased as residual dispersion per span (RDPS) becomes large.

Quality Characteristics and Composition Profile of Traditional Doenjang and Manufactured Doenjang during Storage Time (저장기간에 따른 전통된장과 개량식된장의 이화학적 특성, 기능성분 및 대사체 분석)

  • Kang, Hee-Joo;Kim, Jin-Hee;Kim, Ri-Rang;Kim, Kang Sung;Hong, Sang-Phi;Kim, Min-Jung;Yang, Hye Jeong
    • The Korean Journal of Food And Nutrition
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    • v.29 no.5
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    • pp.785-794
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    • 2016
  • This research was conducted to evaluate quality changes in traditional Doenjang and manufactured Doenjang during a storage period of 8 weeks. Low-salt Doenjang and commercial Doenjang were purchased from different manufacturers and proximate analysis as well as changes in isoflavone, polyphenol, flavonoid contents of the samples were investigated using a mass spectrophotometer. The salinity of traditional Doenjang, low salt Doenjang, and commercial Doenjang were $13.2{\pm}1.15$, $7.17{\pm}2.74$, $10.67{\pm}0.35%$, respectively and the salt concentrations of the soybean pastes did not change during storage. After 8 weeks at $35^{\circ}C$, chromatic values of all the paste samples decreased somewhat, with traditional Doenjang exhibiting fewer changes as compared to manufactured Doenjang. Amino acid nitrogen, acidity, microbial population all tended to increase with time, although some samples showed fluctuations during the test period. Moreover, the total isoflavone contents of traditional Doenjang increased with storage time while that of manufactured Doenjang tended to decrease. The isoflavone aglycone was shown to be the highest in traditional Doenjang, while isoflavone glycoside was abundant in manufactured Doenjang. Total flavonoid contents showed similar trends regardless of samples; initial contents of total flavonoid was 0.6 mg/g which increased to more than twice to 1.4 mg/g at the end of storage period. Composition profile of Doenjang extracts was analyzed using UPLC-Q-ToF.

Effect of Olive-Oil Prepared Tomato Powder (OPTP) and Refining Lycopene on the Physicochemical and Sensory Characteristics of Seasoned Raw Pork During Storage (올리브유처리 토마토 분말과 정제 Lycopene이 저장 중 양념육의 물리화학적 및 관능적 특성에 미치는 영향)

  • Kim, Il-Suk;Jin, Sang-Keun;Kang, Suk-Nam;Hur, In-Chul;Choi, Seung-Youn
    • Food Science of Animal Resources
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    • v.29 no.3
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    • pp.334-339
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    • 2009
  • This study was carried out to determine the effects of olive-oil prepared tomato powder (OPTP) and lycopene on seasoned raw pork. 1.5% OPTP was added in T1 and 3.0% in T2; and 0.03% refining lycopene was added in T3. While in storage, pH values of the treated samples were lower (p<0.05) than those of the control samples. Upon increasing storage, salinity values of OPTP samples increased as well, however, the values of T3 did not change. There were significantly higher TBARS values observed in the OPTP samples compared to control, but no significant difference between T3 and the control samples in TBARS values during storage. VBN values of T2 samples were lower than that of other samples at Day 3 and Day 6 of storage. At Day 9 however, the VBN values of T1 and T2 were significantly higher than those of the control and T3. There was no significant difference between the control and the treated samples in the total plate counts. There were relatively higher redness, yellowness and chromatic values observed in the treated samples than in control. In sensory evaluation, there was no significant difference between the control and the treated samples in color, tenderness, juiciness and overall acceptability.