• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.898-906
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• 2002

In this paper, we investigated the improvement degree of transmission distance of the various initial frequency chirped optical pulse with 5 dBm initial power dependence on the various bit rate and fiber dispersion coefficient, when MSSI(Mid-Span Spectral Inversion) with the optimal pump power condition is adopted for the compensation method for optical pulse distortion. And we analyzed the influence of mutual relation of optical pulse frequency chirp and Kerr effect on the MSSI methods for the long-haul optical transmission through the computer simulation. We found that the compensation degree of distorted optical pulse varies as a consequence of the variation of combined phase modulation of self phase modulation(Kerr effect) and initial frequency chirp parameter dependence on the fiber dispersion coefficient. And we found that, if the transmission bit rate is increased k times, the dispersion coefficient value of dispersion shift fiber is decreased $2^k$ times so as to be almost the same performance of the transmission system with k times lower bit rate.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.177-181
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• 2019

The purpose of this study was to investigate the degree of blocking of blue light of the tips and goggles of the curing light during the dental treatment using the blue light of the light curing. The light curing tips and goggles were placed on a UV-Vis spectrometer and the results of light transmission were analyzed. Comparative analysis. As a result, all four types of light curing tips used in the analysis showed excellent blue light blocking effect. In the case of safety goggles, red-type goggles showed blue light transmittance similar to those of light curing than yellow-type goggles. As a result, it is recommended that the attachment of the light curing with high degree of blue light blocking and the wearing of safety glasses are necessary to protect the eyes. This behavior is thought to reduce persistent irritation and fatigue in the eyes.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.2
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• pp.1-12
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• 1970

In this paper, theoretical and experimental study about the light modulation at X-band(9375MHz) micro wave, using the linear electro-optic effect, has been described. The electro-optic crystal, KDP (potassium dihydrogen phosphate)is used for modulator crystals which is composed resonated modulator. Output performances of modulated wave through movable short positions are presented. It was critically respond from 2. And the output modulated intensity was compared with theoretical curve. Consequently, in spite of many problems remain yet, most promissing and more sucessful modulator configurations are compleely given.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.145.1-145.1
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• 2012

복잡한 공전주기 변화를 보이면서 극심시각 관측 역사가 40년 이상 되는 38개 식쌍성의 공전주기를 연구하였다. 그 별들의 (O-C) 도를 영년주기 감소(또는 증가)와 광시간 효과를 가정하여 분석한 결과, 잘 정의된 영년 변화와 최소 두 개 이상의 광시간 효과가 겹쳐 있음을 발견하였다. 영년주기 감소율은 $-2.0{\times}10^{-12}d/P$에서 $-9.0{\times}10^{-10}d/P$ 사이에 있고, 증가율은 $6.6{\times}10^{-13}d/P$에서 $1.3{\times}10^{-8}d/P$ 사이에 있다. 광시간 궤도 주기는 약 6년에서 150년 사이에 있다. 두 개의 광시간 궤도의 평균 운동 사이에는 모두 commensurability가 모두 존재한다. 이 결과를 쌍성의 진화 및 궤도공명이란 관점에서 논의한다.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.339-344
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• 2013

Application of intense pulsed light (IPL) treatment is an emerging technology with interesting prospects in food preservation. However, information concerning the factors affecting the inactivation of microorganisms and their impact on the quality of fresh-cut food is scarce. In this study, the effects of IPL treatment on the microbial inactivation and physicochemical change in paprika were determined. The viability of bacteria in paprika treated with IPL decreased slightly with the treatment time. In addition, water content was slightly decreased after IPL treatment regardless of the color of paprika. However, except in red paprika, sugar content increased after IPL treatment. The pH of paprika increased in all samples, and the polyphenol content decreased with treatment time, but these differences were very small. After IPL treatment of paprika, vitamin C content increased in yellow and red samples. Hunter color values-lightness (L), redness (a), and yellowness (b)-increased in red paprika, but all values decreased in orange paprika.

• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.162-165
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• 1979

In order to study the red-coloring effects of hot pepper fruit by light treatment during after-ripening period, 'Karak Geumjang No. 2 green hot pepper fruits, Capsicum annuum L., after 30 to 35 days from flowering were harvested and white, red and blue light treatments at the energy level of $40\;{\mu}watt/cm^2/sec$ were given at $25^{\circ}C$. When compared with white light, total chlorophyll content was strikingly decreased by blue light treatment and no difference in the chlorophyll contents between red and white light was observed. The chlorophyll a and b showed a similar decreasing patterns as shown in the case of total chlorophyll. Total carotenoid content was higher in the blue light treatment by 31% than the white light. However, red light decreased the carotenoid condent as compared to the white light treatment. But ${\beta}-carotene$ was not changed by red light as compared to white light. Blue light treatment increased ${\beta}-carotene$ content (0.71 mg%-f.w.) as compared to white light treatment (0.56 mg%-f.w.). Therefore, blue light treatment increased red-coloring responses of hot pepper fruit during after-ripening period. The capsaicin content was slightly increased by blue light and no red light influence was observed.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.239-248
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• 2004

This experiment was carried out to confirm that phytochrome regulates anthocyanin bio-synthesis during cell suspension culture system of grape or not. In suspension culture of grape, maximum accumulation of anthocyanin was observed at the stationary phase under continuous white light condition. From mono-chromatic light interruption for 24h at the 4th or 7th day on the suspension cultured cells, the anthocyanin accumulation was highly enhanced at the light interruption at 7th day than 4th day under all monochromatic light treatment. However, the cell growth patterns were not affected by any light treatment. In the darkness, the anthocyanin synthesis was very low but remarkably increased by blue light or red light irradiation. However, the increase of anthocyanin accumulation by blue or red light was suppressed by far-red light in the suspension cells of grape. This suppression by far-red light on the anthocyanin synthesis also observed on the cells treated red or far-red light alternatively. These results implied that phytochrome regulation system may be involved in the anthocyanin biosynthesis of the suspension grape cells. By RNA expression analysis, chalcone synthase (CHS) gene was expressed highly by blue and red light but low by far-red light. The synergistic increase of CHS gene expression was also observed at the treatment of blue light followed by red for 24h. This result may explain the increase of anthocyanin accumulation in B/R treatment. Although the expression of phytochrome gene (PHYA or PHYB) was not highly increased by all light treatment (blue, red, and far-red light) the expression of both PHYA gene and PHYB gene was increased a little in cells treated red or far-red light. In grape suspension cells, the red light enhanced the anthocyanin synthesis, whereas the far-red light was suppressed. Although it was not confirmed whether or not phytochrome gene is activated in anthocyanin accumulating grape cells, we believed that anthocyanin biosynthesis in grape cells may be regulated under phytochrome signal transduction system.

• Korean Journal of Optics and Photonics
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• v.9 no.1
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• pp.1-4
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• 1998

A compact scanning confocal microscope has been constructed using a quad-detector in a CD-player. The variation of error signal on depth which obtained by a quad-detector is used in the scanning confocal microscope. Bipolar error signals, which is sensitive near a focus, give a surface following effect whiout following the surface. In the case of small depth difference, the difference of materials through the reflection signal has been identified. The image which uses reflection signal only, has been obtained with the same setup. And, the results obtained in two different way were compared and analyzed.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.65-65
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• 2006

• ICROS
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• v.15 no.4
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• pp.19-27
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• 2009

최근에는 여름철 냉방부하가 현격하게 증가하고 있는 상황에서, 일사량 특성공선과 부하특성곡선의 유사성을 이용하여 여름철에 상호보완효과를 얻을 수 있는 태양광발전방식의 보급 활성화는 에너지 소비 측면에서도 매우 바람직하다 할 수 있다.