• ETRI Journal
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• 제30권3호
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• pp.461-468
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• 2008

This paper presents a chromatic dispersion monitoring technique using a clock-frequency component for carrier-suppressed return-to-zero (CSRZ) signal. The clock-frequency component is extracted by a clock-extraction (CE) process. To discover which CE methods are most efficient for dispersion monitoring, we evaluate the monitoring performance of each extracted clock signal. We also evaluate the monitoring ability to detect the optimum amount of dispersion compensation when optical nonlinearity exists, since it is more important in nonlinear transmission systems. We demonstrate efficient CE methods of CSRZ signal to monitor chromatic dispersion for optimum compensation in high-speed optical communication systems.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.307-308
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• 2007

We present a novel chromatic dispersion measurement method using a spectral domain interferometer for single mode optical fiber over a wide spectral range (200 nm). This technique is based on the Mach-Zehnder interferometer using a white light source and spectrometer. A phase was directly retrieved from a measured spectral interferogram to obtain relative group velocity, chromatic dispersion and dispersion slope. The measured results with the proposed method were compared with those obtained using a conventional measurement method. Those results have good agreement with each other. Our proposed method can simply, accurately, and quickly (< 500 ms) measure chromatic information for a short length of optical fiber as well as optical device.

• 한국레이저가공학회지
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• 제2권2호
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• pp.18-26
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• 1999

An innovative real-time weld monitoring technique using chromatic filtering of the thermal radiation from a weld pool is developed. The thermal radiation from the weld pool is focused on an aperture and the transmitted thermal radiation is monitored at two wavelengths with high-speed single-element detectors. Due to the chromatic aberration introduced in the focusing optics, the transmittance curve of thermal radiation varies by the wavelength. Owing to this difference in the transmittance, the local variation of thermal radiation from the weld pool can be monitored by processing the two spectroscopic signals from two detectors. In this paper, the algorithms to monitor the laser power on the weld specimen and the focus shift we investigated and the performances of laser power and focus monitoring are shown for a pulsed Nd:YAG laser welding. The monitoring of the weld pool size variation is also discussed.

• ETRI Journal
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• 제28권2호
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• pp.257-259
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• 2006

In this letter, we will evaluate the performance degradation of a 40 km high-speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters.

• ETRI Journal
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• 제27권3호
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• pp.312-318
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• 2005

Mid-span spectral inversion (MSSI) has to utilize high optical pump power, for its operation principle is based on a nonlinear optical wavelength conversion. In this paper, a low pump-power operation of MSSI-based chromatic dispersion compensation (CDC) has been achieved successfully, for the first time to our knowledge, by introducing a noise pre-reduction scheme in cascaded wavelength conversions with periodically poled $LiNbO_3$ waveguides at a relatively low operation temperature. As preliminary studies, phase-matching properties and operation-temperature dependence of the wavelength converter (WC) were characterized. The WC pumped at 1549 nm exhibited a wide conversion bandwidth of 59 nm covering the entire C-band and a conversion efficiency of -23.6 dB at 11 dBm pump power. CDC experiments were implemented with 2.5 and 10 Gb/s transmission systems over 100 km single-mode fiber. Although it is well-known that the signal distortion due to chromatic dispersion is not critical at a 2.5 Gb/s transmission, the clear recovery of eye patterns was identified. At 10 Gb/s transmission experiments, eye patterns were retrieved distinctly from seriously distorted ones, and notable improvements in bit-error rates were acquired at a low pump power of 14 dBm.

• 한국의상디자인학회지
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• 제12권3호
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• pp.133-143
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• 2010

The purpose of this study was to investigate the clothing image according to gender, coloration of chromatic and achromatic color, and interval of checked pattern. The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 16 color pictures, in which the gender(male, female), interval(0.5cm, 1.5cm, 3.5cm, 5.5cm), and coloration(WR: white+red, WY: white+yellow, WB: white+Blue, WP: white+purple) were manipulated. The 7-point scale was used for evaluation of clothing image. Data were obtained from 192 male college students and 192 female college students living in Seoul, Gwangju, Daegu, Jinju, and Changwon on March 2010. For data analysis, ANOVA and Duncan-test were used by using SPSS program. Results of this study were as follows.; Clothing image according to coloration of chromatic and achromatic color, and interval of checked pattern consisted of six dimensions of attractiveness, appeal, activity, freshness, modesty, and cuteness. Gender showed an independent effect on attractiveness, appeal, activity, freshness, and cuteness. Interval showed an independent effect on attractiveness. Coloration showed an independent effect on appeal, activity, freshness, modesty, and cuteness. Also, interaction effects of gender and coloration on freshness and cuteness were found.

• 한국의류학회지
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• 제32권11호
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• pp.1771-1781
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• 2008

The purpose of this study was to classify the casual image by clothing design elements. This research was done by survey method with 30 kinds of casual image photos selected in fashion magazines. The data was analyzed by Reliability Analysis, Factor Analysis, ANOVA, Duncan's test and MDS. The results of this study are as follows: 1. Casual image was classified by 6 factors. Those were classic-casual, modern-casual, romantic-casual, vintage-casual, sexy-casual and active-casual images. 2. Classic-casual image was well-expressed by A silhouette, fit, chromatic and chromatic color coordinations and hard texture. Modern-casual image was well-expressed by H silhouette, fit and achromatic and achromatic color coordinations. Romantic-casual image was well-expressed by A silhouette, fit and soft texture. Vintage-casual image was well-expressed by H silhouette, combination apparel-fit, chromatic and chromatic color coordinations and fade-out texture. Sexy-casual image was well-expressed by fitted silhouette, tight apparel-fit and combination texture. 3. Casual image was positioned into mostly dynamic and modern on image scale.

• 한국연초학회지
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• 제23권2호
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• pp.156-161
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• 2001

This study was carried out to evaluate the effect of bulk fermentation on chemical, chromatic, and organoleptic characteristics of burley leaf tobacco. The pile of ferment processing was taken up 32 days under the conolitions of leaf moisture contents of $28\pm1%$, with a pressure of some 200kg/$m^2$ within a closed room (mean air temperature and relative humidity ; 20.5$^{\circ}C$ and 58.7%). The pile was opened up and reconstructed two times when the maximum inside temperature reached at $45~46^{\circ}C$. The nicotine content was decreased, but amomnia contents and pH were significantly increased by bulk fermentation. Otherwise, the contents of total nitrogen, total volatile base, organic acids, and fatty acids were not affected by same treatment. The value of L(black to white), a(red to green) and b(yellow to blue) in chromatic characteristics were significantly decreased by bulk fermentation. In sensory test of the cigarettes made by addition of the tormented tobacco leaves after toasting in proportion of 19-25%, no negative characteristics in irritation, taste, and preference were detected in comparison with normally processed cigarettes(19%, 2 years fermentation, toasting). The results suggest that bulk fermentation may be useful to increase the proportion of burley leaf tobacco in the cigarettes and to shorten the period of storage for aging.

• 한국통신학회논문지
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• 제26권11B호
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• pp.1607-1611
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• 2001

매우 짧은 펄스를 이용한 40-Gb/s 광전송의 성능과 전송용 광섬유의 색 분산과의 관계를 컴퓨터 시뮬레이션을 사용하여 연구하였다. 매우 짧은 펄스를 사용할 경우 펄스매우 짧은 펄스를 이용한 40-Gb/s 광전송의 성능과 전송용 광섬유의 색 분산과의 관계를 컴퓨터 시뮬레이션을 사용하여 연구하였다. 매우 짧은 펄스를 사용할 경우 펄스의 넓은 스펙트럼이 광섬유의 색분산과 어우러져서 광섬유의 비선형성에 의한 신호의 왜곡이 억제된다. 이러한 억제의 정도는 광섬유의 색분산, 광신호의 세기 그리고 전송거리 등에 의해 복합적으로 결정된다. 3ps의 길이를 갖는 펄스가 사용되었을 경우 장신호의 세기가 너무 높지 않을 때, 눈 잠김 페널티는 광섬유의 색분산이 D=4ps/nm/km일 경우 가장 컸으며 그 양쪽으로 패널티는 줄어들었다.

• 감성과학
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• 제11권3호
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• pp.325-338
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• 2008

본 연구는 남녀 대학생을 대상으로 유채-무채 배색, 면적비, 성별이 남성복 착용자의 이미지에 미치는 영향을 규명하고자 한다. 이들 단서로 사용된 84개의 자극물에 대한 이미지를 평가하기 위해 경남, 서울, 부산, 대구 등지에 거주하는 남녀 대학생 2016명의 피험자를 대상으로 하였으며 26쌍의 의미미분척도를 요인 분석하여 이미지 차원을 밝혔다. 그 결과 이들 단서들이 어떻게 조합되어 이미지에 영향을 미치는지 규명하였으며 다음과 같은 결론을 얻었다. 유채-무채 배색, 면적비, 성별에 따른 3색 사선 스트라이프 넥타이 착용자의 이미지 차원은 젊음.활동성, 능력성, 매력성, 현시성, 온유성의 5개 차원으로 도출되었으며, 유채-무채 배색, 면적비, 지각자의 성별이 이미지 형성에 미치는 영향은 이미지 차원에 따라 차이를 나타내었다. 이러한 연구결과는 넥타이 디자인 기획 시 소비자의 감성을 충족시킬 수 있는 자료제시가 될 것으로 본다.