• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.176-183
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• 1995

The present work is concerned with the switching conduction characteristics of PI LB films in metal insulator metal sandwiches. By applying various DC voltage bias to MIM junctions, conduction characteristics of junctions can be changed between the high-voltage low-current(off) condition, the low-voltage high-current (on) condition and the medium(mid) condition. Switching conduction characteristics can be also observed in MIM junctions employing some aromatic compounds as insulators. Switching conduction characteristics is assumed to be owing to the existence of aromatic rings, space charge in films, impurities on metal-insulator interface, and difference in work functions of base and top electrodes metal. To study the conduction process of on, off, and mid conductions, we measured I-V, d$^{2}$V/d I$^{2}$-V characteristics of junctions with several different top electrodes under various temperatures. Small conductance changes of junctions can be measured by observing the second derivative, d$^{2}$V/dI$^{2}$, of I-V curve. A dynamical technique is used to get the second derivatives. That is, a finite modulation of the current is applied to the junctions and the second harmonic of the voltage is detected.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.377-380
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• 1997

In order to investigate the electrical characteristics due to the curing condition of silicone gel for Power Semiconductor, the V-I characteristics is studied. For experiment, We have made up several samples of different curing temperature and time such as 1[H],2[H] at 150[$^{\circ}C$], 160[$^{\circ}C$], 170[$^{\circ}C$]. As a result of the V-I characteristics, it is confirmed that the properties of specimen cured at 170[$^{\circ}C$], 2[H] is stable.

• The Korean Journal of Physiology
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• 제17권1호
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• pp.1-11
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• 1983

1) 토끼동방결절의 작은 절편에 미세 전극 두개로 voltage clamp를 하고 과분극에 의하여 활성화되는 내향전류, $i_f$의 동력학적 성상을 분석하였다. 2) 전류 $i_f$는 $10^{-7}g/ml$ TTX와 2 mM $Mn^{2+}$의 존재하에서 과분극 pulse에 의하여 활성화되었으며 그 범위는 $-45\;mV{\sim}-75\;mV$였다. 전류의 크기와 시간경과는 막전압이 과분극될수록 커지고 빨라졌다. 3) Envelope test결과 $i_f$전류는 단일 gate에 의하여 지수합수적 (exponential)으로 조절됨을 보였다. 4) 2 mM의 $Ba^{2+}$에 의하여$i_f$전류의 크기는 감소하고 시간경과도 느려졌으며 반응속도상수와 gating molecule의 열리고 닫히는 반응계수(rate coefficient; ${\alpha}_s$, ${\beta}_s$)와 막전압 관계곡선을 과분극쪽으로 이동시켰다. 이러한 $Ba^{2+}$의 효과는 24 mM $K^+$에 의하여 일부 상쇄되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.797-799
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• 1996

This paper presents a simple method for evaluating of voltage stability using the line flow equation. Line flow equations($P_{ij}$, $Q_{ij}$) are comprised of state variable, $V_i$, ${\delta}_i$, $V_j$ and ${\delta}_j$, and line parameter, r and x. Using the feature of polar coordinate, these equations become one equation with two variables, $V_i$ and $V_j$. Moreover, if bus j is slack bus or generator bus, which is specified voltage magnitude, it becomes One equation with one variable $V_i$, that is, may be formulated with the second-order equation for $V_i^2$. Therefore, solutions are obtained with simple computation. Solutions obtained are used for evaluating of voltage stability through sensitivity analysis. Also, considering of reactive power source, method for evaluating the voltage stability is introduced. The proposed method was validated to 2-bus and IEEE 6-bus system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.254-255
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• 2005

In this paper, we investigated electrical characteristics of the X-ray detector of mercuric iodide (HgI2) film fabricated by PIB(Particle-in-Binder) Method on ITO substrates 17cm$\times$20cm in size with thicknesses ranging from approximately 200${\mu}m$ to 240${\mu}m$. In the present study, using I-V measurements, their electrical properties such as leakage current, X-ray sensitivity, and signal-to-noise ratio (SNR),were investigated. The results of our study can be useful in the future design and optimization of direct active-matrix flat-panel detectors (AMFPD) for various digital X-ray imaging modalities.

• 한국ITS학회 논문지
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• 제17권4호
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• pp.112-123
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• 2018

자율협력주행 도로시스템은 자율주행차와 V2X 통신으로 연결되어 상호정보를 주고받으며 자율주행차의 안전주행을 지원하는 도로인프라 시스템을 말합니다. 본 연구는 자율협력주행 도로시스템 서비스의 성능평가 방안 제시를 목적으로 하며, 도로인프라에서 자율주행차에 정보를 제공하는 I2V 서비스 중 '작업구간 정보제공 서비스'를 예를 들어, 먼저 서비스에 대한 Use Case 분석과 서비스 성능을 확인하기 위해 필요한 요구사항 및 서비스 범위를 정의하고, 이러한 서비스의 성능평가 수행을 위한 평가시스템을 제안하였다. 또한, 본 연구에서 제안한 평가시스템을 활용하여 '작업구간 정보제공 서비스'의 현장시험을 통해 평가 가능여부를 검증하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.45-49
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• 2001

We have investigated physical and electrical properties of the Hf $O_2$/HfS $i_{x}$/ $O_{y}$ thin film for alternative gate dielectrics in the metal-oxide-semiconductor device. The oxidation of Hf deposited directly on the Si substrate results in the H $f_{x}$/ $O_{y}$ interfacial layer and the high-k Hf $O_2$film simultaneously. Interestingly, the post-oxidation N2 annealing of the H102/H1Si70y thin films reduces(increases) the thickness of an amorphous HfS $i_{x}$/ $O_{y}$ layer(Hf $O_2$ layer). This phenomenon causes the increase of the effective dielectric constant, while maintaining the excellent interfacial properties. The hysteresis window in C-V curves and the midgap interface state density( $D_{itm}$) of Hf $O_2$/HfS $i_{x}$/ $O_{y}$ thin films less than 10 mV and ~3$\times$10$^{11}$ c $m^{-2}$ -eV without post-metallization annealing, respectively. The leakage current was also low (1$\times$10-s A/c $m^2$ at $V_{g}$ = +2 V). It is believed that these excellent results were obtained due to existence of the amorphous HfS $i_{x}$/ $O_{y}$ buffer layer. We also investigated the charge trapping characteristics using Fowler-Nordheim electron injection: We found that the degradation of Hf $O_2$/HfS $i_{x}$/ $O_{y}$ gate oxides is more severe when electrons were injected from the gate electrode.e electrode.e.e electrode.e.

• ETRI Journal
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• 제27권3호
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• pp.319-325
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• 2005

In this paper the effect of temperature on the electrical properties of organic semiconductor disperse orange dye 25 (OD) have been examined. Thin films of OD have been deposited on $In_{2}O_{3}$ substrates using a centrifugal machine. DC current-voltage (I-V) characteristics of the fabricated devices $(Al/OD/In_{2}O_{3)$ have been evaluated at varying temperatures ranging from 40 to $60^{\circ}C$. A rectification behavior in these devices has been observed such that the rectifying ratio increases as a function of temperature. I-V characteristics observed in $Al/OD/In_{2}O_{3)$ devices have been classified as low temperature $({\leq} 50^{\circ}C)$ and high temperature characteristics (approximately $60^{\circ}C$). Low temperature characteristics have been explained on the basis of the charge transport mechanism associated with free carriers available in OD, whereas high temperature characteristics have been explained on the basis of the trapped space-charge-limited current. Different electrical parameters such as traps factor, free carrier density, trapped carrier density, trap density of states, and effective mobility have been determined from the observed temperature dependent I-V characteristics. It has been shown that the traps factor, effective mobility, and free carrier density increase with increasing values of temperature, whilst no significant change has been observed in the trap density of states.

• Biomolecules & Therapeutics
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• 제13권1호
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• pp.48-58
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• 2005

The present study was conducted to investigate the effects of nicorandil on arterial blood pressure and vascular contractile responses in the normotensive anesthetized rats and to establish the mechanism of action. Nicorandil (30~300 ${\mu}g/kg$) given into a femoral vein of the normotensive anesthetized rat produced a dose-dependent depressor response. These nicorandil-induced hypotensive responses were not affected by pretreatment with atropine (3.0 mg/kg, i.v.) or propranolol (2.0 mg/kg, i.v.), while markedly inhibited in the presence of chlorisondamine (1.0 mg/kg, i.v.) or phentolamine (2.0 mg/kg, i.v.). Futhermore, after the pretreatment with 4-aminopyridine (1.0 mg/kg/30 min, i.v.) or glibenclamide (50.0 ${\mu}g/kg$/30min) into a femoral vein made a significant reproduction in pressor responses induced by intravenous norepinephrine. In he isolated rat aortic strips, both phenylephrine (10$^{-5}$ M)- and high potassium (5.6 ${\times}\;10^{-2}$ M)-inducedcontractile responses were dose-dependently depressed in the presence of nicorandil (25~100 ${\mu}M$). Collectively, these experimental results demonstrate that intravenous nicorandil causes a dose-dependent depressor action in the anesthetized rat at least partly through the blockade of vascular adrenergic ${\alpha}_1$-receptors, in addition to the well-known mechanism of potassium channel opening-induced vasorelaxation.

• Kyungpook Mathematical Journal
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• 제45권1호
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• pp.67-71
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• 2005

We call K a (1, 1)-knot in M if M is a union of two solid tori $V_1\;and\;V_2$ glued along their boundary tori ${\partial}V_1\;and\;{\partial}V_2$ and if K intersects each solid torus $V_i$ in a trivial arc $t_i$ for i = 1 and 2. Note that every (1, 1)-knot is a tunnel number one knot. In this article, we determine when a tunnel number one knot is a (1, 1)-knot. In other words, we show that any tunnel number one knot with bridge number 3 is a (1, 1)-knot.