• 한국재료학회지
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• 제29권10호
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• pp.647-655
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• 2019

In order to analyze the effect of hot asymmetric rolling on the microstructure and texture of aluminum alloy and to investigate the effect of the texture on the formability and plastic anisotropy of aluminum alloy, aluminum 6061 alloy is asymmetrically rolled at room temperature, $200^{\circ}C$, $350^{\circ}C$, and $500^{\circ}C$, and the results are compared with symmetrically rolled results. In the case of asymmetric rolling, the equivalent strain (${\varepsilon}_{eq}$) is greatest in the upper roll part where the rotational speed of the roll is high and increases with increasing rolling temperature. The increase rate of the mean misorientation angle with increasing temperature is larger than that during symmetrical rolling, and dynamic recrystallization occurs the most when asymmetrical rolling is performed at $500^{\circ}C$. In the case of hot symmetric rolling, the {001}<110> rotated cube orientation mainly develops, but in the case of hot asymmetric rolling, the {111}<110> orientation develops along with the {001}<100> cube orientation. The hot asymmetric rolling improves the formability (${\bar{r}}$) of the aluminum 6061 alloy to 0.9 and reduces the plastic anisotropy (${\Delta}r$) to near zero due to the {111}<110> shear orientation that develops by asymmetric rolling.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1080-1084
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• 1994

Asymmetric inducing effects of substituents attached at nitrogen, the 5-position and boron in oxazaborolidine rings on asymmetric borane reduction of ketones were investigated. Thus, the effect of N-substituents examined with the oxazaborolidines prepared from (lR,2S)-N-alkyl norephedrine derivatives showed the remarkable decrease of enantioselectivities of the product alcohols by the variation of the steric size of alkyl groups on nitrogen from Me${\leftrightarro}$n-Bu(${\simeq}$Bn)${\leftrightarro}$ neopentyl${\leftrightarro}$i-Pr, such as 83${\%}$ ee with 5b, 22${\%}$ ee with 5c, 23${\%}$ ee with 5f, 16${\%}$ ee with 5e, and 3${\%}$ ee with 5d for the reduction of acetophenone. The presence of diphenyl groups at the 5-position enhanced the enantioselectivities dramatically. The effect of B-alkyl substituents in the oxazaborolidines derived from (lR,2S)-ephedrine showed that the enantioselectivities of product alcohols decreased gradually when the substituents were changed from hydrogen to steric bulky groups such as methyl, n-butyl, thexyl and phenyl.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.129-131
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• 2011

Hight speed memory application을 위하여 6.4-Gb/s/channel 4-PAM transceiver가 제안된다. Voltage margin과 time margin용 증가시키기 위하여 asymmetric 4-PAM scheme과 이를 위한 회로를 제안한다. 제안된 asymmetric 4-PAM scheme은 기존 회로에 비하여 송신단에서 33%의 기준전압 노이즈 영향을 줄인다. Channel의 ISI를 줄이기 위해서 transmitter의 1-tap pre-emphasis가 사용된다. 제안된 asymmetric 4-PAM transceiver는 1.2V supply 0.13um 1-poly 6-metal CMOS 공정에서 구현되었다. PLL을 포함한 1-channel transceiver의 면적과 전력소모는 각각 $0.294um^2$와 6mW이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.14-21
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• 2001

An experimental study has been conducted to investigate the heat/mass transfer characteristics within a square film cooling hole with asymmetric inlet flow conditions. The asymmetric inlet flow condition is achieved by making distances between side walls of secondary flow duct and film cooling hole different; one side wall is $2D_h$ apart from the center of film cooling hole, while the other side wall is $1.5D_h$ apart from the center of film cooling hole. The heat/mass transfer experiments for this study have been performed using a naphthalene sublimation method and the flow field has been analyzed by numerical calculation using a commercial code. Swirl flow is generated at the inlet region and the heat/mass transfer pattern with the asymmetric inlet flow condition is changed significantly from that with the symmetric condition. At the exit region, the effect of mainstream on the inside hole flow is reduced with asymmetric condition. The average heat/mass transfer coefficient is higher than that with the symmetric condition due to the swirl flow generated by the asymmetric inlet condition.

• 대한기계학회논문집B
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• 제26권7호
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• pp.937-944
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• 2002

An experimental study has been conducted to investigate the heat/mass transfer characteristics within a square film cooling hole with asymmetric inlet now condition. The asymmetric inlet now condition is achieved by making distances between side walls of the secondary now duct and the film cooling hole different; one side wall is $2D_h$ apart from the center of the film cooling hole, while the other side wall is $1.5D_h$ apart from the center of the film cooling hole. The heat/mass transfer experiments for this study have been performed using a naphthalene sublimation method and the now field has been analyzed by numerical calculation using a commercial code. Swirl now is generated at the inlet region and the heat/mass transfer pattem with the asymmetric inlet now condition is changed significantly from that with the symmetric condition. In the exit region, the effect of mainstream on the inside hole now is reduced with the asymmetric condition. The average heat/mass transfer coefficient is higher than that with the symmetric condition due to the swirl now generated by the asymmetric inlet condition.

• PNF and Movement
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• 제14권1호
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• pp.53-57
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• 2016

Purpose: This study aimed to examine the correlation between the asymmetric ratio of occlusal force of the temporomandibular joint and the thickness of the middle scalene muscle. Methods: The study measured the occlusal force of the right and left temporomandibular joints in 30 subjects (12 males and 18 females). Pearson's correlation analysis was performed to examine the effect of occlusal force on the asymmetric ratio of the thickness of their middle scalene muscles by measuring the force using ultrasound after the break. Results: The correlation between the asymmetric ratio of occlusal force and muscle thickness is 0.41, according to Pearson's correlation coefficient. Therefore, the result shows a moderate correlation with the asymmetric ratio of the temporomandibular joint depending on differences in the thickness of the middle scalene muscle. Conclusion: Based on the above results, the asymmetric ratio of occlusal force was found to correlate with the thickness of the middle scalene muscle. Thus, therapeutic intervention is required for the middle scalene muscle in the case of temporomandibular joint disorder.

• 대기
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• 제24권2호
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• pp.207-223
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• 2014

The bogussing method was further developed by incorporating the asymmetric component into the symmetric bogus tropical cyclone of the Structure Adjustable Balanced Vortex (SABV). The asymmetric component is separated from the disturbance field associated with the tropical cyclone by establishing local polar coordinates whose center is the location of the tropical cyclone. The relative importance of wave components in azimuthal direction was evaluated, and only two or three wave components with large amplitude are added to the symmetric components. Using the Weather Research and Forecast model (WRF), initialized with the asymmetric bogus vortex, the track and central pressure of tropical cyclones were predicted. Nine tropical cyclones, which passed over Korean peninsula during 2010~2012 were selected to assess the effect of asymmetric components. Compared to the symmetric bogus tropical cyclone, the track forecast error was reduced by about 18.9% and 17.4% for 48 hours and 72 hours forecast, while the central pressure error was not improved significantly. The results suggest that the inclusion of asymmetric component is necessary to improve the track forecast of tropical cyclones.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1218-1223
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• 2007

In this study, we experimentally investigate the equivalent ring theory for a slightly asymmetric ring. The slightly asymmetric ring has mode pair and frequency pair due to the small asymmetry and this mode pair generates beat in vibration and sound. In this paper, a slightly asymmetric ring is modeled as the equivalent ring, i.e., the assemblage of a symmetric ring and imperfect point masses. The equivalent ring has the same mode pair condition as that of the original asymmetric ring. Effect of the additional mass attachment is investigated by the equivalent ring theory and the result is compared with those of the measurement and the finite element analysis. It is confirmed that the original ring and the equivalent ring show the same change in frequency and mode under the various additional imperfection mass conditions. The equivalent ring theory explains how the asymmetric elements influence the mode characteristics and provides useful information to tune the beat property.

• 한국표면공학회지
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• 제44권5호
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• pp.179-184
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• 2011

This work investigated the effect of duty cycle and pulse frequency on the microstructures and properties of titanium nitride thin films deposited by asymmetric bipolar pulsed DC sputtering system. Oscilloscope traces of the I-V waveforms indicate high power and high current density outputs during the asymmetric bipolar pulsed mode. The grain size decreases with decreasing duty cycle. The duty cycle has a strong influence not only on the microstructural properties but also on the mechanical properties of titanium nitride films. Comparing with the continuous DC sputtering, the titanium nitride films prepared by pulsed DC asymmetric bipolar process exhibit better properties.

• 재무관리연구
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• 제25권1호
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• pp.109-140
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• 2008

본 연구는 투자자간의 의견차이가 수익률의 비대칭적 변동성 현상에 영향을 주는지 검증하고, 정보량이 비대칭적 변동성에 미치는 영향을 검증하였다. 2000년 1월 4일부터 2005년 12월 29일까지의 유가증권시장 주가지수의 일별 종가와 거래량을 표본자료로 이용하였으며, 일별 거래량과 시장가치 수준별로 개별기업을 대상으로 각각 포트폴리오를 구성하여 분석하였다. 실증분석에서 TGARCH 모형을 기본모형으로 이용하였으며, 투자자간 의견차이의 대용변수인 거래량을 추가한 수정모형을 통하여 분석하였다. 주가지수를 대상으로 기본모형을 분석한 결과는 비대칭적 변동성이 존재하는 것으로 나타났으나, 수정모형의 분석 결과에서는 비대칭적 변동성이 유의적으로 감소되는 것으로 나타났다. 그리고 포트폴리오를 대상으로 분석한 결과는 정보량(거래량, 시장가치)이 많을수록 비대칭성 계수와 비대칭성 비율이 대체적으로 높은 것으로 나타났으며, 또한 기본모형에 비해 수정모형에 의해 추정된 비대칭성 계수와 비율이 제한적이나마 유의적으로 감소하는 것으로 나타났다. 이상의 결과에서 우리나라 증권시장에서 투자자간 의견차이가 비대칭적 변동성을 설명하는 요인 중의 하나라고 할 수 있으며, 정보량이 비대칭적 변동성에 제한적으로 영향을 미치는 것을 알수 있었다. 한편, 시장가치가 높은 포트폴리오일수록 비대칭적 변동성이 높게 나타났는데 이는 투자자간 의견차이 뿐만 아니라 정보의 신뢰성 차이에 기인한 투자자들의 의견수정 정도에 의해 나타난 것으로 사료된다.