• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1338-1342
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• 2011

In this paper, threshold voltage characteristics have been analyzed as one of short channel effects occurred in double gate(DG)MOSFET to be next-generation devices. The Gaussian function to be nearly experimental distribution has been used as carrier distribution to solve Poisson's equation, and threshold voltage has been investigated according to projected range and standard projected deviation, variables of Gaussian function. The analytical potential distribution model has been derived from Poisson's equation, and threshold voltage has been obtained from this model. Since threshold voltage has been defined as gate voltage when surface potential is twice of Fermi potential, threshold voltage has been derived from analytical model of surface potential. Those results of this potential model are compared with those of numerical simulation to verify this model. As a result, since potential model presented in this paper is good agreement with numerical model, the threshold voltage characteristics have been considered according to the doping profile of DGMOSFET.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.1
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• pp.10-17
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• 1985

A new method is suggested for the solution of plane elasticity problems. With use of the dislocation model in the crack problems, the basic scheme of this method is to find equilibrium Burgers vectors of dislocations which are distributed along the boundary of the first fundamental boundary value problems. The stress distribution in the region can be found by superposition of the contributions of each dislocation. The method is applied to three cases with known analytical solutions, and to a V-notched specimen under uniaxial tension. The numerical results are compared with other available solutions. This method is effective and simple in its use, compared with other numerical methods. The method also provides very accurate solutions in the region except near the boundary where the discretization error is significant. The extrapolation method is suggested for the stresses in the boundary region. Extensive application are also suggested for a general estimate of the computational efficiency of the method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.57-62
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• 2008

This paper deals with a comparison of individual and connecting grounding electrode for potential rise. When a test current flowed through grounding electrode, potential rise was measured and analyzed for grounding method using a electrolytic tank in real time. In order to analyze the potential rise of grounding systems, a hemispherical water tank experimental apparatus was studied. Potential rise was measured and analyzed regarding the grounding method and distance by using this apparatus. The apparatus was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured by the horizontal moving probe of the potentiometer. The grounding electrodes were designed and fabricated with ground rods on a scale of one-eightieth. Potential rises of individual grounding electrode were higher than those of connecting grounding electrode. The distributions of surface potential are dependent on the distance from grounding electrode.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.35-42
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• 2010

We use conformal mapping method to derive the analytical expressions for calculating electrostatic fields and electric potentials surrounding the conductor-backed coupled coplanar waveguide(CBCCPW) structure. Using the derived expressions, the electrostatic fields and potentials are computed at various points of the CBCCPW's geometry and the field and potential distributions are analyzed. The proposed method provides a faster and simpler calculation of the field distributions than the full-wave analysis method because no iterations are required. This method can be widely applied to the analysis of microwave integrated circuits using coupled line, such as coupler, filter, and microstrip antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1409-1413
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• 2013

This paper analyzed the change of subthreshold current for channel doping concentration of double gate(DG) MOSFET. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The potential distribution was obtained as the analytical function of channel dimension, using the boundary condition. The subthreshold current had been analyzed for channel doping concentration, and projected range and standard projected deviation of Gaussian function. Since this analytical potential model was verified in the previous papers, we used this model to analyze the subthreshold current. As a result, we know the subthreshold current was influenced on parameters of Gaussian function and channel doping concentration for DGMOSFET.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.3
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• pp.6-12
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• 1983

The visual evoked potentials were measured using 19 electrodes attached to the scalp in 5 normal and 4 abnormal subjects during visual stimulation and these data were sampled for computer processing with 500 Hz sampling frequency. The center of potential distributions and its time-dependent locus were estimated from these potential distributions using weighting matrix which was determined by the electrodes' position coordinates. In normal subjects these estimated electrical signals were shown to propagate from the frontal lobe to the occipital lobe of the cortex following the known visual pathway. In abnormal subjects, there were significant differences in these estimated propagation pathway. The relationships among this model, the point source model and the dipole source model were analyzed.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.200-211
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• 2016

To support cross potential array and direct potential array, the array for leakage detection of all kinds of water facilities is proposed and it is named as the D-Lux array. The D-Lux array data are arranged to a coloured matrix and it is called the D-Lux view. Low potential difference of anomalous zone shown in D-Lux view implies the indication of leakage zone. Furthermore, for an intuitive interpretation of D-Lux array, equipotential distribution map is made by using D-Lux and direct potential array data. Equipotential distribution map makes us possible to predict import point, export point and the path of water leakage that we could have not anticipated in D-Lux view and the graphs. The water tank experiment and numerical analysis were carried out as preparatory experiment and the field explorations were conducted at a concrete weir and a fill dam. As a result, effective and specific detection of leakage path was possible for the concrete weir and the fill dam.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2643-2648
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• 2015

This paper analyzes the phenomenon of drain induced barrier lowering(DIBL) for doping profiles in channel of asymmetric double gate(DG) MOSFET. The DIBL, the important short channel effect, is described as lowering of source barrier height by drain voltage. The analytical potential distribution is derived from Poisson's equation to analyze the DIBL, and the DIBL is observed according to the change of doping profile to influence on potential distribution. As a results, the DIBL is significantly influenced by projected range and standard projected deviation, the variables of channel doping profiles. The change of DIBL shows greatly in the range of high doping concentration such as $10^{18}/cm^3$. The DIBL increases with decrease of channel length and increase of channel thickness, and with increase of bottom gate voltage and top/bottom gate oxide film thickness.

• Annual Conference on Human and Language Technology
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• 2012.10a
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• pp.29-34
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• 2012

본 연구는 한국어 어순재배치(scrambling) 문장의 이해 과정에서 발생되는 대뇌 활동을 사건관련전위(event-related Potentials; ERPs) 이용하여 살펴보기 위하여 실시되었다. 네 개의 어절로 구성된 표준 어순 문장(일년만에 마님이 영감을 만났어요.)과 어순재배치 문장(일년만에 영감을 마님이 만났어요.)을 어절별로 제시하고 첫 번째 명사구(NP1), 두 번째 명사구(NP2), 동사(Verb)의 시작점(onset)에서 측정한 뇌파를 비교하였다. 뇌파의 분석은 대뇌 영역을 중심선(midline), 중앙(medial), 편측(lateral)로 나누어 전후 분포(anterior-posterior distribution)와 정중선(midline)의 열에 의해 좌우 반구(hemisphere)로 분리하여 분석하였다. 분석 결과 중심선 영역에서 표준 어순에 비해 뒤섞기 어순에서 300-500ms 시간 창(time window)에서 큰 부적 전위(negative potential)가 관찰되었으며 이는 어순재배치로 인한 N400효과로 해석되며 P600효과는 관찰되지 않았다. 특히 첫 번째 명사구에서 문장유형(표준 어순 vs. 어순재배치)의 차이가 가장 크게 관찰되었으며 두 번째 명사구에서는 중앙에서 문장유형과 반구(좌우반구)의 상호작용이 관찰되었고, 동사에서는 문장유형과 반구, 문장유형과 전극 위치의 전후 분포와의 상호작용이 관찰되었다. 본 연구 결과에서 관찰된 N400효과는 독일어와 일본어를 대상으로 한 어순재배치 연구 결과와 유사하며 한국어 어순재배치 문장에 관한 사건관련 전위를 고찰하였다는 점에서 의의가 있다.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.122-126
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• 2004

직격뇌가 높은 건축물에 치거나 인접 건물로부터 뇌전류가 유입되었을 때 잘못된 피뢰설비로 인한 피해는 매우 심각한 실정이다. 낙뢰가 치는 순간에 반도체와 같은 민감한 전자부품을 사용하는 전자 및 통신기기는 뇌전류로 인한 전자기장의 영향으로 오동작이 발생하거나 부품의 손상을 입기가 쉽다. 본 논문에서는 건축물 구조체에 직격뇌가 유입되었을 때 건축물 구조체 및 건물 주위에 나타나는 전위분포특성을 연구하였다. 본 논문에서 30m 높이 건축물의 상부 모서리와 중앙부 그리고 건축물 하부 모서리와 중앙부로 뇌전류가 유입된다고 가정하여 건축물의 전계분포특성을 시뮬레이션하였으며, 뇌전류는 2중 지수함수형태로 모의된 20kA 임펄스 서지 전류를 주입하였다. 뇌서지 전류의 주파수 특성은 Fast Fourier Transform(FFT)을 이용하여 얻었으며, 얻어진 주파수 값을 이용하여 건축물 구조체와 인접지역의 Scalar Potentials과 Electric Fields의 특성을 시뮬레이션하였다. 또한 철골 빔 건축물의 철골 빔에 직접 뇌전류가 유입되는 경우와 건물 하부의 접지전극에 뇌전류가 유입되는 경우로 분리 하여 연구하였다. 그 결과 뇌전류의 유입경로가 건축물의 모서리부분 보다는 중심부에 위치될 때 전위 및 전계 크기가 작았으며 건축 철골구조물보다 건축물 하부에 접지전극이 설치될 때 더 낮은 전계 값을 갖는 것을 확인하였다.