• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 동계학술발표회 논문집
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• pp.11-12
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• 2007

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 동계학술발표회 논문집
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• pp.299-300
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• 2006

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1878-1881
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• 2002

The capacitance of nonlinear component such as a CMOS inverter varies largely around the threshold voltage. We measured the far-end crosstalk of two parallel microstrip lines with the CMOS inverter load near the threshold voltage of the CMOS inverter, The negative voltage of the crosstalk agrees with that for a 4pF capacitor toad. The positive voltage of the crosstalk hardly changes of the amplitude of the input step voltage.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.149-152
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• 2005

A new methodology to detect forest fire burnt scars at near real time using MODIS (Moderate-resolution Imaging Spectroradiometer) data is presented here with a goal of introducing a new and improved capability to detect forest fire burnt scars in Thailand. This new technology is expected to increase the efficiency and effectiveness of the forest fire tackling resources distribution and management of the country. Using MODIS data in burnt scars detection has two major advantages - high availability of data and high resolution per performance ratio. Results prove the near real time algorithm suitable and working well in order to monitor the forest fire dynamic movement. The algorithm is based on the threshold separated linear equation of burnt and un-burnt. A ground truth experiment confirms the burnt and un-burnt? areas characteristics (temperature and NDVI). A threshold line on a scatter plot of Band I and Band 2 is determined to separate the burnt from un-burnt pixels. The different threshold values of NDVI and temperature use to identify pixels' anomaly, abnormal low NDVI and high temperature. The overlay (superimpose) method is used to verify burnt pixels. Since forest fire is a dynamic phenomenon, MODIS burnt scars information is suiting well to fill in the missing temporal information of LANDSAT for the forest fire control managing strategy in Thailand. This study was conducted in the Huai-Kha-Kaeng (HKK) Wildlife Sanctuary, Thailand

• 한국결정성장학회지
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• 제16권6호
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• pp.235-239
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• 2006

Micro-pulling down$({\mu}-PD)$법을 이용하여 직경 $0.8{\sim}1.0mm$, 길이 $30{\sim}35mm$의 ZnO가 첨가된 near-stoichiometric $LiNbO_3$, 단결정을 성장하였다. 성장된 결정의 결정구조를 powder x-tay diffraction(XRD) patterns으로 확인하였고, electron probe micro analysis(EPMA)를 이용하여 결정내 Zn 이온들이 균일하게 분포되었음을 확인하였다. 또한 2 mol% 이상의 ZnO 첨가시 $OH^-$ 흡수밴드의 특성이 크게 변화함을 관찰함으로써 ZnO 첨가량에 일치한 역치(threshold)가 존재함을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.866-869
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• 2015

시스템-온-칩(system-on-chip, SoC)내에 집적되는 소자의 수가 기하급수적으로 증가함에 따라 에너지 효율을 높이기 위한 전압 스케일링은 필수적인 요소가 되었다. 문턱전압 근처 동작(near-threshold voltage computing, NTC)은 칩 에너지 효율을 10배 가까이 향상시킬 수 있는 기술로서 전통적인 초 문턱전압 동작(super-threshold voltage computing, STC)의 한계를 극복할 수 있을 것으로 기대되고 있다. 저성능 매니코어(manycore) 시스템으로 동작하는 NTC는 에너지 효율을 극대화할 수 있지만 성능 유지를 위한 코어 수의 증가는 상당한 면적 증가를 수반한다. 본 논문에서는 성능, 전력 및 면적 간의 trade-off를 고려하여 면적 제약조건 하에서 NTC 코어 수 및 캐시 및 클러스터 크기 결정 알고리즘을 통해 요구 성능을 만족시키면서 전력 소모를 최적화하는 방법을 제안한다. 실험을 통해 면적 제약조건 속에서 기존의 STC 코어에서의 성능을 유지한 채 전력소모를 약 16.5% 감소시킬 수 있음을 보여준다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권3호
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• pp.240-250
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• 2010

Double Gate MOSFETs (DG MOSFETs) with doping in one or two thin layers of an otherwise intrinsic channel are simulated to obtain the transport characteristics, threshold voltage and leakage current. Two different device structures- one with doping on two layers near the top and bottom oxide layers and another with doping on a single layer at the centre- are simulated and the variation of device parameters with a change in doping concentration and doping layer thickness is studied. It is observed that an n-doped layer in the channel reduces the threshold voltage and increases the drive current, when compared with a device of undoped channel. The reduction in the threshold voltage and increase in the drain current are found to increase with the thickness and the level of doping of the layer. The leakage current is larger than that of an undoped channel, but less than that of a uniformly doped channel. For a channel with p-doped layer, the threshold voltage increases with the level of doping and the thickness of the layer, accompanied with a reduction in drain current. The devices with doped middle layers and doped gate layers show almost identical behavior, apart from the slight difference in the drive current. The doping level and the thickness of the layers can be used as a tool to adjust the threshold voltage of the device indicating the possibility of easy fabrication of ICs having FETs of different threshold voltages, and the rest of the channel, being intrinsic having high mobility, serves to maintain high drive current in comparison with a fully doped channel.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.219-222
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• 2004

The effects of short fiber and particle hybrid reinforcement on fatigue crack propagation behaviors in aluminum matrix composites have been investigated. Single and hybrid reinforced 6061 aluminum containing same 20 $Al_2O_3\;volume\%$ with four different constituent ratios of short fibers and particles were prepared by squeeze casting method and tested to check the near-threshold and stable crack growth behavior. The fatigue threshold of the composites increased with portion of particle contents and showed the improved crack resistance especially in low stress intensity range. Addition of particle instead of short fiber also increased fracture toughness due to increase of inter-reinforcement distance. These increase in both fatigue threshold and fracture toughness eventually affected the fatigue crack growth behavior such that the crack growth curve shift low to high stress intensity factor value. Overall experimental results were shown that particle reinforcement was enhanced the fatigue crack resistance over the whole stress intensity factor range.

• 대한기계학회논문집B
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• 제27권8호
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• pp.1158-1164
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• 2003

Steady-state structure and acoustic-pressure responses of $H_2$/Air counterflow diffusion flames are studied numerically with a detailed chemistry in view of acoustic instability. The Rayleigh criterion is adopted to judge acoustic amplification or attenuation from flame responses. Steady-state flame structures are first investigated and flame responses to various acoustic-pressure oscillations are numerically calculated in near-equilibrium and near-extinction regimes. The acoustic responses of $H_2$/Air flame show that the responses in near-extinction regime always contribute to acoustic amplification regardless of acoustic-oscillation frequency Flames near extinction condition are sensitive to pressure perturbation and thereby peculiar nonlinear responses occur, which could be a possible mechanism in generating the threshold phenomena observed in combustion chamber of propulsion systems.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1248-1248
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• 2001

Mastitis is a major problem for the global dairy industry and causes substantial economic losses from decreasing milk production and considerable compositional changes in milk, reducing milk quality. The potential of near infrared (NIR) spectroscopy in the region from 1100 to 2500nm and chemometric method for classification to detect milk from mastitic cows was investigated. A total of 189 milk samples from 7 Holstein cows were collected for 27 days, consecutively, and analyzed for somatic cells (SCC). Three of the cows were healthy, and the rest had mastitis periods during the experiment. NIR transflectance milk spectra were obtained by the InfraAlyzer 500 spectrophotometer in the spectral range from 1100 to 2500nm. All samples were divided into calibration set and test set. Class variable was assigned for each sample as follow: healthy (class 1) and mastitic (class 2), based on milk SCC content. The classification of the samples was performed using soft independent modeling of class analogy (SIMCA) and different spectral data pretreatment. Two concentration of SCC - 200 000 cells/ml and 300 000 cells/ml, respectively, were used as thresholds fer separation of healthy and mastitis cows. The best detection accuracy was found for models, obtained using 200 000 cells/ml as threshold and smoothed absorbance data - 98.41% from samples in the calibration set and 87.30% from the samples in the independent test set were correctly classified. SIMCA results for classes, based on 300 000 cells/ml threshold, showed a little lower accuracy of classification. The analysis of changes in the loading of first PC factor for group of healthy milk and group of mastitic milk showed, that separation between classes was indirect and based on influence of mastitis on the milk components. The accuracy of mastitis detection by SIMCA method, based on NIR spectra of milk would allow health screening of cows and differentiation between healthy and mastitic milk samples. Having SIMCA models, mastitis detection would be possible by using only DIR spectra of milk, without any other analyses.