• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3800-3804
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• 2013

In this study, molecular dynamics simulations of SPC/E (extended simple point charge) model have been carried out in the canonical NVT ensemble over the range of temperatures 300 to 550 K with and without Ewald summation. The quaternion method was used for the rotational motion of the rigid water molecule. Radial distribution functions $g_{OO}(r)$, $g_{OH}(r)$, and $g_{HH}(r)$ and self-diffusion coefficients D for SPC/E water were determined at 300-550 K and compared to experimental data. The temperature dependence on the structural and diffusion properties of SPC/E water was discussed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.356.2-356.2
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• 2014

Spin Transfer Torque (STT) is of great interest in data writing scheme for the Magneto-resistive Random Access Memory (MRAM) using Magnetic Tunnel Junction (MTJ). Scalability for high density memory requires ferromagnetic electrodes having the perpendicular magnetic easy axis. We investigated CoZr as the ferromagnetic electrode. It is observed that interfacial magnetic anisotropy is preferred perpendicular to the plane with thickness dependence on the interfaces with Pt layer. The anisotropy energy (Ku) with thickness dependence shows a change of magnetic-easy-axis direction from perpendicular to in-plane around 1.2 nm of CoZr. The interfacial anisotropy (Ki) as the directly related parameters to switching and thermal stability, are estimated as $1.64erg/cm^2$ from CoZr/Pt multilayered system.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.344-345
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• 2012

The Gate-Induced-Drain-Leakage (GIDL) current with channel doping and width dependence are characterized. The GIDL currents are found to increase in MOSFETs with higher channel doping levels and the observed GIDL current is generated by the band-to-band-tunneling (BTBT) of electron through the reverse-biased channel-to-drain p-n junction. A BTBT model is used to fit the measured GIDL currents under different channel-doping levels. Good agreement is obtained between the modeled results and experimental data. The increase of the GIDL current at narrower widths in mainly caused by the stronger gate field at the edge of the shallow trench isolation (STI). As channel width decreases, a larger portion of the GIDL current is generated at the channel-isolation edge. Therefore, the stronger gate field at the channel-isolation edge causes the total unit-width GIDL current to increases for narrow-width devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.14-14
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• 2011

Graphene is known to possess excellent thermal properties, including high thermal conductivity, that make it a prime candidate material for heat management in ultra large scale integrated circuits. For device applications, the key parameters are the thermal expansion coefficient and the thermal conductivity. There has been no reliable experimental determination on the thermal expansion coefficient of graphene whereas the estimates of the thermal conductivity vary widely. In this work, we estimate the thermal expansion coefficient of graphene on silicon dioxide by measuring the temperature dependence of the Raman spectrum. The shift of the Raman peaks due to heating or cooling results from both the intrinsic temperature dependence of the Raman spectrum of graphene and the strain on the graphene film due to the thermal expansion mismatch with silicon dioxide. By carefully comparing the experimental data against theoretical calculations, it is possible to determine the thermal expansion coefficient. The thermal conductivity is measured by estimating the thermal profile of a graphene film suspended over a circular hole of the substrate.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.15-18
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• 2003

HTS(High Temperature Superconductor) tapes have dependence on critical characteristics such as electric, magnetic field and temperature. In order to confirm these effects, we examined the current transport characteristics of HTS tapes. First, after being fed DC and AC, the dependence of HTS tapes of 10cm on external magnetic field was investigated. On centeral region of HTS tape, about 1cm, external magnetic field was applied. Second, after applying DC of 50A to HTS tapes, we applied time variable magnetic field about 100mT and investigated the quench characteristics. Finally, AC, which is about 10 times of I$_{c}$, was applied to HTS tapes and over current characteristics were investigated. The data acquired in this study will be used as a source for the study of HTS cable conductor which is supposed to carry on.n.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.1061-1067
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• 2005

The resonant frequency modulation of $YBa_2Cu_3O_{7-x}$ meander lines has been investigated as functions of optical pulse energy and temperature by using a network analyzer. The frequency-domain measurements are performed by controlling both the resonant frequency and the frequency width. The meander lines, configured in a microstrip geometry, are illuminated by optical pulses from an actively mode-locked Nd:YAG laser. The variation of the resonant frequency shows a quadratic dependence on the reduced optical pulse energy $P/P_c$, where $P_c$ is defined as the critical optical pulse energy at which resonance signal has disappeared. As for the dependence on temperature, the results are in good agreement with the previously reported data.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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• pp.71-80
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• 2006

A nonparametric Bayesian multiple comparisons problem (MCP) for dependence parameters in I bivariate exponential populations is studied here. A simple method for pairwise comparisons of these parameters is also suggested. Here we extend the methodology studied by Gopalan and Berry (1998) using Dirichlet process priors. The family of Dirichlet process priors is applied in the form of baseline prior and likelihood combination to provide the comparisons. Computation of the posterior probabilities of all possible hypotheses are carried out through Markov Chain Monte Carlo method, namely, Gibbs sampling, due to the intractability of analytic evaluation. The whole process of MCP for the dependent parameters of bivariate exponential populations is illustrated through a numerical example.

• 한국공간구조학회논문집
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• 제4권1호
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• pp.61-68
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• 2004

풍향풍속계와 구조 모니터링 시스템을 설치하여 강풍과 거물의 동적 특성을 계측하였다. 계측건물은 속초의 산기슭에 위치하고 있다. 감쇠율과 고유진동수의 진폭 의존성을 분석하였다. 감쇠율의 진폭의존성은 9%로서, 가속도진폭이 증가함에 따라서 감쇠율이 명료하게 증가하는 경향을 보였다. 계측데이터에서 얻은 동적 특성의 경향은 사용성 평가시 건물의 동적 특성을 평가하는데 유용하게 사용되리라 기대된다.

• 생물정신의학
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• 제16권2호
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• pp.127-132
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• 2009

Marchiafava-Bignami disease(MBD) is a rare complication of chronic alcoholism characterized by symmetrical demyelination of the corpus callosum. We report a case of MBD in a Korean patient having chronic alcohol dependence. The patient exhibited mental depression, weakness of all four limbs and dysarthria. Laboratory data showed mild hyponatremia. Magnetic resonance imaging(MRI) revealed unusual symmetrical resolving lesions of the putamen in addition to the typically observed lesion of the corpus callosum. The neurologic disturbances were gradually improved with the normalization of low plasma sodium levels. Marked improvement of abnormal MRI findings was noted after thiamine supplement, though the patient still exhibited severe cognitive impairment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.1119-1122
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• 2000

This paper describes on RF circuit simulation technique, especially on a RF modeling and a model extraction of a LDMOS(Lateral Diffused MOS) that has gate-width (Wg) dependence. Small-signal model parameters of the LDMOSs with various gate-widths extracted from S-parameter data are applied to make the relation between the RF performances and gate-width. It is proved that a source inductance (Ls) was not applicable to scaling rules. These extracted small-signal model parameters are also utilized to remove extrinsic elements in an extraction of a large-signal model (using HP Root MOSFET Model). Therefore, we can omit an additional measurement to extract extrinsic elements. When the large-signal model with Ls having the above gate-width dependence is applied to a high-power LDMOS module, the simulated performances (Output power, etc.) are in a good agreement with experimental results. It is proved that our extracted model and RF circuit simulation have a good accuracy.