• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.76-81
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• 2002

In order to study the fatigue crack and retardation mechanism in variable loading, the effects of crack tip branching in crack growth retardation were examined. The characteristics of crack tip branching behavior were considered with respect to microstructure and crack tip branching angle was examined. Crack tip branching was observed along the grain boundary of finite and pearlite structure. It was found that the branching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving farce to branching angle was examined. The effective crack driving farce (K$\_$eff/) decreased as the branching angle increased. The rate of decrease was 33% for kinked type and 29% for forked one. It was confirmed that the effect of crack tip branching is a very important factor in crack growth retardation. Therefore, crack branching effect should be considered in building the hypothetical model to predict crack growth retardation.

• Tribology and Lubricants
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• 제24권6호
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• pp.326-331
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• 2008

The contact surfaces between mold and target should be in parallel for a proper imprinting process. However, large size of contacting area makes it difficult for both mating surfaces (mold and target planes) to be in all uniform contact with the expected precision level in terms of thickness and position. This is caused by the waviness of mold and target although it is very small relative to the area scale. The gripping force for both mold and target by the vacuum chuck is other major effect to interrupt the uniform contact, which must be avoided in imprinting mechanism. In this study, the cause of non-conformal contact mechanism between mold and target is investigated with the consideration of deformation due to the vacuum gripping for the size $470{\times}370\;mm^2$ LCD panel.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
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• pp.269-272
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• 2006

Surface contacts between mold and target should be in parallel for the imprinting mechanism. However, the size of contacting area makes it difficult for both mating surfaces to be in all contact because of precision level of the imprinting machine and the waviness of mold and target. The gripping force for both mold and target with the vacuum chuck is also major effect to interrupt the full contact, which must be avoided in imprinting mechanism. In this study, the preliminary study for the causes of non-uniformity of contacting surfaces such as mold and target is performed with $470{\times}370mm^2$ LCD panel size.

• Elastomers and Composites
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• 제26권4호
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• pp.287-295
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• 1991

The mixing process with carbon black is important in the rubber industries. However, it is difficult to characterize the mixing mechanism of the carbon black. The mixing mechanism(distributive mixing and dispersive mixing) was discribed in this paper. The effect of fill factor on the mixing of the carbon black was studied. The dispersive mixing ability increases with increasing fill factor. However, the distributive mixing ability decreases with increasing fill factor. The effect of the carbon black content on the rheological property of the material was studied in this paper. The viscosity of the material increases with increasing the carbon black content. However, the elasticity of the matarial decreases with the carbon black content.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1093-1094
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• 2006

Magnetic characteristics observed in BiSrCaCuO superconductor were studied. In the measurement of differential conductance, it was cleared that the mechanism of magnetic memory effect couldn't be explained by using conventional flux flow model. By changing the density of external magnetic flux, changes in inductance of a coil in which a superconducting bar inserted were also measured. The results showed that the filament model was valid to explain the mechanism of the occurrence of a voltage in superconducting sample. It was concluded that the electromagnetic characteristics arose from the interaction between the trapped magnetic flux and weak link of the filament formed in the superconducting bulk.

• 한국해양공학회지
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• 제7권1호
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• pp.147-155
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• 1993

The effect of stress waveforms on corrosin fatigue and the role of dissolution mechanism in 3NilCr steel and 20Ni maraging steel have been investigated in aerated 3% NaCl solution and synthetic seawater under sinusoidal, triangular, square, positive sawtooth, negative sawtooth, and trapezoidal stress waveforms with open circuit at frequency of 1Hz and stress ratio of 0.1. The crack growth rates under square waveform were substantially lower than under sinusoidal and triangular waveforms, but the crack growth rates under sinusoidal waveform were slightly higher under triangular waveform. For a given frequency the growth rates under the positive sawtooth waveform are higher than those under the negative sawtooth waveform. The fatigue crack growth rates of most specimens were in good agreement with the values calculated by the model based on the dissoultion mechanism.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.512-513
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• 2018

트랩-보조-터널링(Trap-Assisted-Tunneling; TAT)은 실제 터널링 전계 효과 트랜지스터 (TFET)의 임계 이하 기울기를 저하시키고 시뮬레이션에서 고려되어야한다. 그러나, 그 메커니즘은 라인 터널링 타입 L형 TFET(LTFET)에서는 잘 알려져 있지 않았다. 본 연구는 dynamic nonlocal Schenk 모델을 이용한 LTFET의 TAT 메커니즘을 연구한다. 이 연구에서는 터널링 이벤트를 위해서 phonon assisted and direct band가 모두 고려되었다.

• Steel and Composite Structures
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• 제6권5호
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• pp.387-400
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• 2006

This paper discusses the composite mechanism and its effect upon the behavior of a steel reinforced concrete (SRC) member subjected to a flexural load. The relationship between member strength and deformation is established using the bond strength between the steel and reinforced concrete. An analytical model is proposed and used to incorporate the sectional strains and bond strength at the elastic and inelastic stages for moment-curvature relationship derivation. The results from the flexural load tests are used to validate the accuracy of the proposed model. Comparisons between the experimental information and the analytical results demonstrate close moment-curvature relevance, which justifies the applicability of the proposed method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.129-130
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• 2005

The electrical stress has a major effect on the long-term reliability of the thyristor. Therefore, it is needed to analyze the relationship between reliability and stress. In this paper, we investigate the device failure mechanism which induced by the stress. And also investigate the effect of the thermal stress on the device failure and relationship between electrical and thermal stress. Two-dimensional process simulator ATHENA and device simulator ATLAS are used to analyze the failure mechanism of the device.

• 생약학회지
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• 제49권4호
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• pp.285-290
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• 2018

Harmine, a beta-carboline alkaloid isolated from the seeds of Peganum harmala has been reported as a promising drug candidate for cancer therapy. However, the effect of harmine on breast cancer remains still unclear. In this study, the effect of harmine on the cell proliferation, migration, and invasion of breast cancer MDA-MB231 cells and the underlying mechanism were investigated. The results indicated that harmine inhibited the proliferation MDA-MB231 cells in a dose-dependent manner and markedly suppressed migration and invasion of MDA-MB231 cells. The mechanism involved in part through Notch signaling. The Notch activity was significantly inhibited by harmine treatment and harmine suppressed the expression of Jagged1 which is a key ligand to activate Notch signaling. These findings suggest a novel mechanism of harmine on anti-cancer activity and harmine may act as a potential therapeutic drug for breast cancer treatment.