• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.360-365
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• 2020

A technique for the reduction of pulse pile-up effect in digital pulse-shape discrimination (PSD) of neutrons and gamma-rays with organic scintillation detectors is presented. The technique is based on an electronic reduction of the effective decay-time constant of scintillation pulses while retaining the PSD information of the pulses. The experimental results obtained with a NE213 liquid scintillation detector in a mixed radiation field of neutrons and gamma-rays are presented, demonstrating a figure of merit (FOM) of 1.20 ± 0.05 with an energy threshold of 350 keVee (electron equivalent energy) when the effective length of the pulses is reduced to 50 ns.

• Speech Sciences
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• v.4 no.2
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• pp.5-15
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• 1998

This paper proposes a speech state-dependent spectral subtraction method to regulate the blind spectral subtraction for improved enhancement. In the proposed method, a modified subtraction rule is applied over the speech selectively contingent to the speech state being voiced or unvoiced, in an effort to incorporate the acoustic characteristics of phonemes. In particular, the objective of the proposed method is to remedy the subtraction induced signal distortion attained by two state-dependent procedures, spectrum sharpening and minimum spectral bound. In order to remove the residual noise, the proposed method employs a procedure utilizing the masking effect. Proposed spectral subtraction including state-dependent subtraction and residual noise reduction using the masking threshold shows effectiveness in compensation of spectral distortion in the unvoiced region and residual noise reduction.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.955-956
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• 2006

Fe-doped $TiO_2$ nanopowders were prepared by mechanical alloying (MA) varying Fe contents up to 8.0 wt.%. The UV-vis absorption showed that the UV absorption for the Fe-doped powder shifted to a longer wavelength (red shift). The absorption threshold depends on the concentration of nano-size Fe dopant. As the Fe concentration increased up to 4 wt.%, the UV-vis absorption and the magnetization were increased. The benefical effect of Fe doping for photocatalysis and ferromagnetism had the critical dopant concentration of 4 wt.%. Based on the UV absorption and magnetization, the dopant level is localized to the valence band of $TiO_2$.

• Journal of Pharmaceutical Investigation
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• v.12 no.1
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• pp.23-30
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• 1982

The effect of various surfactants on the absorption of antipyrine was studied using goldfish and rat. The results are as follows. The threshold concentration of antipyrine was reduced by various surfactants. Overturn time and death time of goldfish, in solution containing different concentration of antipyrine was reduced by the presence of various surfactants. Plots of reciprocal death time versus antipyrine concentration were linear with a positive concentration intercept such as minimum effective concentration. The absorption of antipyrine from rat small intestine was increased by administration with surfactants. As results, is believed to be one of rendering the goldfish membrane or rat small intestine more permeable to antipyrine.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.4
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• pp.451-456
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• 2014

A compact model of a depletion-mode silicon-nanowire (Si-NW) pH sensor is proposed. This drain current model is obtained from the Pao-Sah integral and the continuous charge-based model, which is derived by applying the parabolic potential approximation to the Poisson's equation in the cylindrical coordinate system. The threshold-voltage shift in the drain-current model is obtained by solving the nonlinear Poisson-Boltzmann equation for the electrolyte. The simulation results obtained from the proposed drain-current model for the Si-NW field-effect transistor (SiNWFET) agree well with those of the three-dimensional (3D) device simulation, and those from the Si-NW pH sensor model also agree with the experimental data.

• Structural Engineering and Mechanics
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• v.29 no.4
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• pp.433-453
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• 2008

The equation of motion of a one way (vertical) spanning strip wall, as an assembly of two rigid bodies, is presented. Only one degree of freedom is needed to completely describe the wall response as the bodies are assumed to be perfectly rectangular and are allowed to rock but not to slide horizontally. Furthermore, no arching action occurs since vertical motion of the upper body is not restrained. Consequently, the equation of motion is nonlinear, with non constant coefficients and a Coriolis acceleration term. Phenomena associated with overburden to self weight ratio, motion triggering, impulsive energy dissipation, amplitude dependency of damping and period of vibration, and scale effect are discussed, contributing to a more complete understanding of experimental observations and to an estimation of system parameters based on the wall characteristics, such as intermediate hinge height and energy damping, necessary to perform nonlinear time history analyses. A comparison to a simple standing, or parapet, wall is developed in order to better highlight the characteristics of this assembly.

• Physical Therapy Korea
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• v.1 no.1
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• pp.61-66
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• 1994

The purpose of this study was to investigate the effect of a single treatment o voltage pulsed current (HVPC) on edema reduction. Hind limbs of 23 anesthetized were injured by dropping a 400 g weight onto the plantar aspects of the feet. On limb of each frog was randomly selected to receive 30 minutes of continuous, 12 cathodal HVPC at voltages 10 % less than motor threshold levels. Limb volumes measured by water displacement before trauma and at predetermined intervals hours posttrauma. Sources of significant differences were determined by t-test HVPC significantly (p<0.05) reduced edema formation. We hypothesize that HVP also be effective in controlling edema formation after impact injuries in humans.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.9
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• pp.447-453
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• 2001

In this paper, a new auto-focusing algorithm for digital cameras is proposed. One of the primary concerns of digital image processing is to increase image quality, and the most important factor for degrading the images is the blurring effect due to inexact focusing. The blurring effect occurs when the focusing lens is located on an unsuitable position. Therefore, focusing on an object should be proceeded before acquiring images. The proposed auto-focusing algorithm is MMDT(min-max difference threshold), and the performance of the proposed algorithm is evaluated by the use of the focus curve. It is shown that the proposed algorithm is superior to other previous auto-focusing algorithms in both the focus shape and computation time aspects. Especially, the improvement of the focus curve shape in both monotonousness and slope indicates that focusing can be done rapidly in comparison with other previous proposed algorithms.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.245-248
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• 2011

The scaling down of metal oxide semiconductor field-effect transistors (MOSFETs) for the last several years has contributed to the reduction of the scaling variables and device parameters as well as the operating voltage of the MOSFET. At the same time, the variation in the electrical characteristics of MOSFETs is one of the major issues that need to be solved. Especially because the issue with variation is magnified as the drive voltage is decreased. Therefore, this paper will focus on the variations between electrical characteristics and drain voltage. In order to do this, the test patterned multi-finger MOSFETs using 90-nm process is used to investigate the characteristic variations, such as the threshold voltage, DIBL, subthreshold swing, transconductance and mobility via parasitic resistance extraction method. These characteristics can be analyzed by varying the gate width and length, and the number of fingers. Through this modeling scheme, the characteristic variations of multi-finger MOSFETs can be analyzed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.430-430
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• 2010

MICC 방법으로 제작된 TFT는 large grain과 그에 따른 grain boundary의 감소로 인하여여, 소자의 전기적 특성을 좋게 할 수 있다. 본 연구에서는 bi-layer channel의 large grain size TFT를 제작하여 소자의 전기적 특성을 비교하였다. Channel의 width / length의 크기는 각 각의 경우 $7/5{\times}2$, $10/5{\times}2$, $15/5{\times}2$ (${\mu}m$)로 하였다. 소자의 성능 측정 결과 Field-effect mobility의 경우에는 channel width가 증가할 수록 감소하는 경향성을 나타내었으며, Threshold voltage의 경우에는 조금 감소하는 경향성은 있었으나 변화의 폭이 매우 작았다. Output characteristics 의 경우에는 모든 set에서 좋은 saturation 특성을 보였다. 이것은 current croding이 없었다는 것을 의미하는데, 큰 grain size로 인한 효과로 해석 할 수 있다. 본 연구에서는 bi-layer channel에서 corner effect에 중점을 두어 소자의 전기적 특성 변화에 대하여 논하였다.