• 융복합기술연구소 논문집
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• 제4권2호
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• pp.11-15
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• 2014

Magnet gear transfers a high speed torque of the driving side to a low speed following side. Of course, the torque is amplified as much as a ratio between pole number of magnet gears constituting both sides through ferromagnet modulator. However, the parameters of the overall magnetic system influence the transmitting torque strongly. They include a pole number of permanent magnet, magnet thickness, reducing ratio, harmonic modulator thickness, and open ratio etc. In this paper, the influences of the parameters are analyzed using finite element method tool. By comparison, a desirable design specification is proposed, including a recommended modulator pattern.

• 한국자기공명학회논문지
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• 제1권2호
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• pp.79-94
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• 1997

The solution structure of bovine pancreatic trypsin inhibitor(BPTI) has been refined by NMR chemical shift data of C${\alpha}$H using classical molecular dynamics simulation. The structure dependent part of the observable chemical shift was modeled by ring current effect, magnetic anisotropy effect from the nearby groups, whereas the structure independent part was replaced with the random coil shift. A new harmonic function derived from the differences between the observed and calculated chemical shifts was added into physical force field as an pseudo potential energy term with force constant of 250 kJmol-1 ppm-2. During the 1.5 ns molecular dynamics simulation with chemical shift restraints BPTI has accessed different conformation space compared to crystal and NOE driven structure.

• Structural Engineering and Mechanics
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• 제18권2호
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• pp.195-209
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• 2004

By means of the two-dimensional basic equations of transversely isotropic magneto-electro-elastic media and the strict differential operator theorem, the general solution in the case of distinct eigenvalues is derived, in which all mechanical, electric and magnetic quantities are expressed in four harmonic displacement functions. Based on this general solution in the case of distinct eigenvalues, a series of problems is solved by the trial-and-error method, including magneto-electro-elastic rectangular beam under uniform tension, electric displacement and magnetic induction, pure shearing and pure bending, cantilever beam with point force, point charge or point current at free end, and cantilever beam subjected to uniformly distributed loads. Analytical solutions to various problems are obtained.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.18-21
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• 2001

This paper describes the method of vibration supprssion on a control algorithm using Neuro-Fuzzy Theory in Linear Pulse Motor (LPM). The total thrust force Is distorted by magnetic and coil flux, and we classify the harmonic parts of it. A modulated current from harmonic components of static thrust characteristics of LPM compensates with reference current to total thrust force. Low vibration is obtatained by the method of current compensation using ANFIS.

• Nuclear Engineering and Technology
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• 제40권3호
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• pp.213-224
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• 2008

The pumping of coolant in a liquid metal fast reactor may be performed with an annular linear induction electro-magnetic (EM) pump. Linear induction pumps use a traveling magnetic field wave created by poly-phase currents, and the induced currents and their associated magnetic field generate a Lorentz force, whose effect can be the pumping of the liquid metal. The flow behaviors in the pump are very complex, including a time-varying Lorentz force and pressure pulsation, because an induction EM pump has time-varying magnetic fields and the induced convective currents that originate from the flow of the liquid metal. These phenomena lead to an instability problem in the pump arising from the changes of the generated Lorentz forces along the pump's geometry. Therefore, a magneto-hydro-dynamics (MHD) analysis is required for the design and operation of a linear induction EM pump. We have developed a time-harmonic 2-dimensional axisymmetry MHD analysis method based on the Maxwell equations. This paper describes the analysis and numerical method for obtaining solutions for some MHD parameters in an induction EM pump. Experimental test results obtained from an induction EM pump of CLIP-150 at the STC "Sintez," D.V. Efremov Institute of Electro-physical Apparatus in St. Petersburg were used to validate the method. In addition, we investigated some characteristics of a linear induction EM pump, such as the effect of the convective current and the double supply frequency (DSF) pressure pulsation. This simple model overestimated the convective eddy current generated from the sodium flow in the pump channel; however, it had a similar tendency for the measured data of the pump performance through a comparison with the experimental data. Considering its simplicity, it could be a base model for designing an EM pump and for evaluating the MHD flow in an EM pump.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.853-859
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• 2015

진동대 실험 시 진동대와 구조물 사이에 발생하는 상호작용을 파악하기 위하여 1자유도 전단건물의 조화진동 실험을 전자기력으로 구동되는 힘-제어 진동대를 이용하여 수행하였다. 실험에서는 진동대와 전단건물의 수평방향 가속도를 측정하였으며, 실험 결과를 이해하기 위한 방법으로 전단건물의 진동대 실험을 조화하중이 작용하는 비구속 2자유도계로 이상화하였다. 이상화 된 이론모델의 운동방정식으로부터 전단건물과 진동대의 가속도를 구하였으며, 이들 가속도를 가진력에 대한 비로 나타낸 증폭계수와 진동대의 가속도 진폭에 대한 전단건물의 가속도 진폭의 비인 전달계수를 구하였으며, 이들 결과를 실험결과와 비교하여 진동대와 전단건물 사이에 발생하는 상호작용을 파악하였다.

• 전기학회논문지
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• 제58권3호
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• pp.509-515
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• 2009

When a squirrel cage induction motor is loaded, the magnetic noise can increase depending on the load current. It is due to the variation of air gap harmonic fluxes from the rotor current induced by loading. This unfavorable noise can be anticipated by analysing the radial force waves in the air gap, the mode shapes of them, and stator core natural frequencies at each mode. With the experimental tests with the different rotor slot numbers, the variation of magnetic noise depending on the load current is studied and the method to reduce the magnetic noise is suggested with the newly developed magnetic noise analysis program.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권6호
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• pp.255-262
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• 2001

This paper deals with characteristic analysis method of the slotless type Permanent Magnet Linear Synchronous Motor(PMLSM) using the space harmonic method. Analysis models of the PM and the armature current are described by the magnetization configurations taking into account the 2D and 3D distribution. In 3D analysis, the thrust and normal force can be calculated more accurately, because it can consider the z component flux density which is impossible in 2D analysis. In order to verify the validity of the proposed method, the results of the analytic method are compared with not only the experimental ones but ones of Finite Element Method(FEM).

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제2B권4호
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• pp.162-167
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• 2002

This paper presents the dynamic analysis method for a slotless permanent magnet linear synchronous motor (PMLSM) using the 3-D space harmonic method. Instantaneous emf and thrust are considered by movement of the PM and instantaneous armature current instead of $K_E$ (back-emf constant) and $K_F$(thrust force constant) for accurate results. The results of magnetic field distribution, back-emf, inductance, and thrust are in agreement with 2-D FEM and experimental results. To confirm the validity of this method, the calculated results are compared to measured ones.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권3호
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• pp.122-127
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• 2003

This paper presents a new time-stepping 3-D analysis method coupled with an external circuit with motion equation for dynamic transient analysis of induction machines. In this method, the magneto-motive force (MMF) generated by induced current is modeled as a passive source in the magnetic equivalent network. So, by using only scalar potential at each node, the method is able to analyze induction machines with faster computation time and less memory requirement than conventional numerical methods. Also, this method is capable of modeling the movement of the mover without the need for re-meshing and analyzing the time harmonics for dynamic characteristics. From comparisons between the results of the analysis and the experiments, it is verified that the proposed method is capable of estimating the torque, harmonic field, etc. as a function of time with superior accuracy.