• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.918-919
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• 2008

This paper deals with the DC-DC converter with high efficiency using the minimum reactor. In this paper, the proposed convert uses the air core reactor for ZCS(zero currunt switching) which can minimize the core losses and removes the over switching losses by soft switching. The proposed converter is verified by the modes analysis and computer simulation to prove the theoretical background and adequacy.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.255-263
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• 2005

Migration experiments of THO and 237Np have performed through a sampled granite core in Chemlab2 probe at the Aspo hard Rock laboratory. The elution curves of THO were analysed to determine hydraulic properties such as the extent of dispersion effect according to flow rates. The retardation phenomena of the solutes were observed and described with elution curves and migration plumes. After migration test, the rock core was opened, and the remaining radioactivities on the rock fracture surfaces were measured. The transport process was simulated with a two-dimensional channel model. The mass transport process was described with three types of basic processes ; advection, sorption and matrix diffusion. By the combination of these processes, effects of each process on transport were described in terms of elution curves and migration plumes. By comparing the simulation results to the experimental one, it was possible to analyse the retardation effect quantitatively.

• Journal of Sensor Science and Technology
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• v.24 no.3
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• pp.194-201
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• 2015

The current sensor is used in industrial devices and power utilities. Core materials of these current sensors are divided into mainly two groups as silicon steel and fermalloy. Silicon steel has a wide saturation bandwidth but low sensitivity during low-current, whereas permalloy has a short saturation bandwidth but high sensitivity during low-current. In this paper, laminated silicon steel and permalloy by equal ratio is proposed to improve the linearity and saturation of current sensor. It is proved that the proposed core material has larger bandwidth than fermalloy as well as higher sensitivity than silicon steel. When comparing simulation results by FLUX 3D, the proposed method has also better performance than the previous core materials.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.266-272
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• 2006

Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were developed for 67 molecules of 2-amino-benzothiazole-6-anilide derivatives against lymphocyte-specific protein tyrosine kinase (P56 LCK). The molecular field analysis (MFA) and receptor surface analysis (RSA) were employed for QSAR studies and the predictive ability of the model was validated by 15 test set molecules. Structure-based investigations using molecular docking simulation were performed with the crystal structure of P56 LCK. Good correlation between predicted fitness scores versus observed activities was demonstrated. The results suggested that the nature of substitutions at the 2-amino and 6-anilide positions were crucial in enhancing the activity, thereby providing new guidelines for the design of novel P56 LCK inhibitors.

• Journal of Korean Association for Spatial Structures
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• v.17 no.3
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• pp.65-73
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• 2017

Recently, the trend is emerging a variety of irregular tall buildings. It is important to design the building for lateral load according to this trend. Fluid Structure Interaction(FSI) simulation can be performed to understand the vibrations of the structure against dynamic wind loads. In order to make the physical characteristics of the actual structure and the analytical model the same, we studied core inserting equivalent stiffness modeling method. As a result of this analysis, the stiffness of the structure can be set similar to that of the two axes of the structure, and turbulence can be reproduced through the acceleration tendency.

• Journal of Magnetics
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• v.22 no.2
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• pp.196-202
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• 2017

The occurrence of ferroresonance in electrical systems including nonlinear inductors such as transformers will bring a lot of malicious damages. The intense ferromagnetic saturation of the iron core is the most influential factor in ferroresonance that makes nonsinusoidal current and voltage. So the nonlinear behavior modeling of the magnetic core is the most important challenge in the study of ferroresonance. In this paper, the ferroresonance phenomenon is investigated in a single phase transformer using the finite element method and considering the hysteresis loop. Jiles-Atherton (JA) inverse vector model is used for modeling the hysteresis loop, which provides the accurate nonlinear model of the transformer core. The steady-state analysis of ferroresonance is done while considering different capacitors in series with the no-load transformer. The accurate results from copper losses and iron losses are extracted as the most important specifications of transformers. The validity of the simulation results is confirmed by the corresponding experimental measurements.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.634-639
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• 2011

This paper presents a study on the design parameters that consider the magnetic saturation effect in a rotor core of a synchronous reluctance motor. Two important design parameters in a rotor are selected to analyze the saturation effect of a synchronous reluctance motor, particularly in a rotor core. The thickness of the main segment, which is the main path of the d-axis flux, and the end rip, which affects the q-axis flux, are analyzed using the d-axis and q-axis inductances. Moreover, the characteristics of torque and torque ripple when magnetic saturation takes place are analyzed. The saturation effect is verified by comparing the reluctance torque between the experiment and FEM simulation.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.97-98
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• 2012

본 논문은 코어의 다양한 재질, 단면적으로 인한 인덕터의 특성변화를 시뮬레이션 하기 위해 PSIM의 Saturable Core를 이용하여 인덕터 구성을 한다. 특히 전기자동차의 LDC (Low-voltage DC-DC Converter)용 인덕터의 Test-Bed를 구성하고, 인덕터 설계 시 코어의 변화에 따른 인덕터 특성의 변화를 시뮬레이션을 통해 구현한다. 또한 설계된 인덕터를 시뮬레이션에 구현하여 비 이상적인 특성을 가지는 인덕터를 구현하고, 이를 통해 시뮬레이션을 통한 인덕터 검증의 필요성을 제시한다.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1326-1338
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• 2017

The continuous energy Monte Carlo neutron transport code, MC21, was coupled to the CTF subchannel thermal-hydraulics code using a combination of Consortium for Advanced Simulation of Light Water Reactors (CASL) tools and in-house Python scripts. An MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 6 demonstrated good agreement with MC21/COBRA-IE and VERA solutions. The MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 7, Watts Bar Unit 1 at beginning of cycle hot full power equilibrium xenon conditions, is the first published coupled Monte Carlo neutronics/subchannel T-H solution for this problem. MC21/CTF predicted a critical boron concentration of 854.5 ppm, yielding a critical eigenvalue of $0.99994{\pm}6.8E-6$ (95% confidence interval). Excellent agreement with a VERA solution of Problem 7 was also demonstrated for integral and local power and temperature parameters.

• Proceedings of the KIEE Conference
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• summer
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• pp.310-312
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• 2004

Generally, instrument transformer of the core type have been used for measuring current. Because instrument transformer has defects, electronic instrument was appeasred. This paper is introduced a basic concept and thoery of electronic instrument and described the the simulation of core type CT and no saturation CT. The evaluation of CT models implemented using EMTP(Electro Magnetic Transients Program) was carried out. The result of comparison both core type CT and no saturation CT are presented.