• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.71-72
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• 2015

배터리의 랜들 등가회로 모델은 기본적으로, 전달 저항 Rct, 전기 이중층 커패시턴스 Cdl, 내부저항 Ri, 그리고 개방회로전압 Voc의 4가지 파라미터로 구성 된다. 본 논문은 실험에 의해 리튬이온 배터리의 모델링을 위한 기본적 4가지 파라미터를 추출하고 운전조건에 따른 특성을 분석한다. 분석 결과를 이용하여 본 연구자에 의하여 제작된 전기 스쿠터의 SOC(State of Charge)를 추정하는 알고리즘을 제안한다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.134-134
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• 2009

원자층 증착법을 이용하여 platinum group metal(Ru, Ir, Pt). metal nitride(TaN, TiN, AlN), 그리고 metal oxide($Al_2O_3$, $TiO_2$)을 증착하고, 미세구조와 공정 변수가 내산화성, 내부식성, 저항 및 온도저항계수에 미치는 영향을 연구하였다. proto-type의 전자저항막 제조를 통해 종래의 TaN 전자저항막에 비해 우수한 내부식성 및 내산화성을 가짐을 확인하였다.

• Composites Research
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• v.25 no.6
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• pp.205-210
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• 2012

The single carbon fiber tensile test was performed with electrical resistance measurement. Tensile property of single carbon fiber which accompanied by the relationship between the electric resistance and the strain was investigated. Since the collected data showed a linear relationship between them, the coefficient of fiber slip ratio (FSR) was obtained by computation. The fragmentation specimen (FS) was tested under tensile loading, and the single carbon fiber broke first due to the stress transferring form matrix to reinforcing fiber. The stress distribution of carbon fiber could be observed via the electrical resistance change. Slipping between carbon fiber and matrix was predicted based on the fragmentation test results, and the FSR was used to evaluate interfacial adhesion comparatively. The large FSR indicated poor interfacial bonding. Work of adhesion between carbon fiber and matrix was measured to verify the FSR method, and two results exhibited a consistent conclusion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1627-1633
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• 2011

Injection molds are generally fabricated by assembling a number of plates in which the core and cavity components are assembled. This assembled structure has a number of contact interfaces where the heat transfer characteristics are affected by thermal contact resistance. In previous studies, numerical approaches were investigated to predict the effect of thermal contact resistance on the temperature distribution of injection molds. In this study, thermal-fluid coupled numerical analyses are performed to take into account the thermal contact effect on the numerical evaluation of the mold filling characteristics. Comparisons with experimental results show that the proposed coupled analysis provides more reliable results than the conventional analyses in predicting the mold filling characteristics by taking into account the effect of thermal contact resistance inside the injection mold assembly.

• Transactions of the Korean hydrogen and new energy society
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• v.3 no.2
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• pp.55-62
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• 1992

To improve the MCFC performance it is important to distingush between polarization losses occuring in the individual electrodes and other components. In this study a current interruption technique has been applied to a MCFC unit cell having a reference electrode to separately study the contributions of IR loss and other polarization losses. At a current density of $150mA/cm^2$ the IR-free polarization of a Ni anode was about 60mV while that of a NiO cathode was 130mV and the Ohmic loss of the cell was as large as 170mV suggesting that both the cathode and the cell structure need further improvement. The thin-film electrode model was used to simulate the performance of the electrodes. Both andoe data and cathode data were successfully fitted.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.41-49
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• 2012

The effects of operating temperature and electrode gap distance on electricity generation were investigated in two-chamber type MFCs. Voltages across the external resistor $(100\;{\Omega})$ were enhanced approximately 1.4 times by the increase of operating temperature from $30^{\circ}C$ to $34^{\circ}C$. The open circuit voltages (OCVs) were increased by the increase of temperature and the maximum power of MFC was obtained at higher current condition by increasing temperature and reducing electrode gap distance. The maximum power densities were enhanced from 1.9 to 2.4 times according to the experimented electrode gap distances by increasing temperature of $4^{\circ}C$. The electricity generation was increased with the decrease of electrode gap distance. The effects of operating temperature and electrode gap distance were closely connected with the internal resistance of MFC system. That is, the increase of temperature and decrease of electrode gap distance reduced the internal resistance of MFC, resulting in the enhancement of electricity generation of MFC.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.2
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• pp.157-166
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• 1996

This paper presents the optimum termination method of a TEM Cell, which utilizes hybrid distributed termination resistor array networks. Current stream on the septum, and on the terminal end of a TEM Cell is analyzed by numerical analysis. By circuit analysis, the optimum resistor array network is designed based on the result of the analysis, which assures efficient power dissipation, and current stream traveling straight and uniform. Thermovision photos were taken for comparing the conventional termination network on which each resistor is arranged at regular intervals, with the suggested optimum termination network on which each resistor is arranged for current distribution. The comparison of the results of thermovision photos shows a good agreement with those obtained by numerical analysis.

• Geophysics and Geophysical Exploration
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• v.22 no.3
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• pp.160-167
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• 2019

Resistivity inversion result may be distorted if the seepage line fluctuation within central core with the change of reservoir water level as well as the conductivity of the reservoir water is not taken into consideration because the reservoir dike is composed of three-dimensional (3D) resistivity structure. Consequently, to accurately analyze the resistivity changes inside the reservoir dike according to the change of reservoir water level, 3D electrical resistivity modeling for the 2D survey line considering topography and physical properties of dam components was carried out. In addition, 2D inversion was performed with the simulated 2D resistivity data for a given 3D model in order to compare it with the inversion result of real field data. For 283 reservoirs in Korea, 2D inversion results for the simulated 2D data and field 2D resistivity data were compared. Finally, the reservoirs with an inversion ratio of 50% or less were selected as reservoirs that require further precise investigation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.876-885
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• 2000

A new and simple method is presented for determining the parasitic resistances of MESFET and HEMT from the measured S-parameters under normal active bias without depending on additional DC measurements or iteration or optimization process. The presented method is based on the fact that the difference between source resistance(Rs) and drain resistance(Rd) can be obtained from the measured Z-parameters under zero bias condition. It is possible to define the new internal device including intrinsic device and 3 parasitic resistances by elimination the parasitic inductances and capacitances from the measured S-parameters. Three parasitic resistances are calculated easily from the fact that the real parts of Yint,11 and Yint,12 of intrinsic Y-parameters are zero theoretically and the relations between S-,Z-, Y-matrices. The calculated parasitic resistances using the presented method and successively calculated equivalent circuit parameters give modeled S-parameters which are in good agreement with the measured S-parameters up to 400Hz.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1650_1651
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• 2009

DC/DC 승압 컨버터는 인덕터 내부 저항으로 인하여 부하 저항의 변화가 시스템 동작점에 영향을 미치게 되며, 이로 하여 제어기 설계의 기준이 되는 선형화된 모델은 불확실성을 가지게 된다. 본 논문은 인덕터의 내부 저항과 출력단의 부하 변동으로 인한 불확실성에 대하여 출력 전압의 강인성을 향상시키기 위해 PI 관측기 기반 적분형 상태 변수 궤환 제어기를 제안한다. PI 관측기는 불확실한 시스템 제어에 널리 사용되는 오차의 적분항을 Luenberger 관측기에 추가한 형태로써 불확실성에 강인한 추정 성능을 보인다. 모의실험을 통해 불확실성이 존재하는 경우 제안된 제어기의 강인성을 확인하고 설계된 관측기가 Luenberger 관측기에 비해 상태변수 추정 성능이 우수함을 보인다.