• Steel and Composite Structures
• /
• 재36권6호
• /
• pp.617-629
• /
• 2020

The purpose of this paper is to depict the effect of rotation and initial stress on a magneto-thermoelastic medium with diffusion. The problem discussed within memory-dependent derivative in the context of the three-phase-lag model (3PHL), Green-Naghdi theory of type III (G-N III) and Lord and Shulman theory (L-S). Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique. Numerical results for the field quantities given in the physical domain and illustrated graphically in the absence and presence of a magnetic field, initial stress as well as the rotation. The differences in variable thermal conductivity are also presented at different parameter of thermal conductivity. The numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. Some special cases are also deduced from the present investigation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.16-18
• /
• 2008

Several methods are proposed in the literature for losses segregation of single phase induction motor. Generally we could divide two methods for experimental determination of losses segregation for single phase induction motor. The one is relatively complicated method based on Parameter estimation of single phase induction motor. The other is simple method based on IEEE Standard 114. Segregation of losses in single phase induction motor is more complicated than that in three phase induction motor, because of the backward magnetic field component in the motor and multiplicity of different single phase type. In this paper, therefore, we studied losses segregation of capacitor-run single phase induction motor.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.77-79
• /
• 2008

This paper deals with extraction of design parameters of Linear Switched Reluctance Motor (LSRM) based on force calculation using space harmonic analysis, 2D Finite Element Method (FEM) and experimental measurement. First, analytical solutions for flux density due to mover winding currents are derived in terms of magnetic vector potential and a 2D rectangular coordinate system, for the case when the mover is located at aligned and unaligned position. The analytical results are compared with those obtained from a 2D FEM Second, using Fourier series expansion, this paper predicts the force profile of LSRM analytically.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.86-88
• /
• 2003

The efficiency of electric machine is important due to increase of interest about energy saving. Single Phase Line Start Permanent Magnet Synchronous Motor has high efficiency and power factor. LSPMSM offer a high efficiency as compared induction motor which are used in the home appliance. The analysis and design of LSPMSM is difficult because of unbalanced rotating magnetic field, nonlinear characteristics and rotor saliency. To consider these effects, F.E.M(Finite Element Methods) is coupled equivalent circuit methods. In this paper, a methods of analysis and design using F.E.M and equivalent circuit is represented.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
• /
• pp.350-353
• /
• 2004

This study was conducted for a rapid and simple method using GC/FID and SPME to dectermin gasonline and chlorinated solvents simultaneity. A sodium chloride concentration of 25%(vol/w) combined with such as magnetic stirried, an absorption time of 20min, an extraction temperature of 4$0^{\circ}C$, the volume of minimized 50mL of gaseous phase and a desorption time of 5min pleprovided the greatest sensitivity while maintaining analytical efficiency. Analytical parameter such as linearity was also evaluated. The linear range extend from 30 to 500ppb. The results of chlorinated solvents and gasoline mixed samples showed that solvents have been completely removed from the sample preparation step and more accurated than those obtained by the other methods.

• Tribology and Lubricants
• /
• 제11권2호
• /
• pp.56-62
• /
• 1995

The anisotropic pressure distribution of the hydrodynamic bearing may generate the unstable vibration phenomenon over a certain speed. These vibrations, known as whirl, whip or rotor instability, cannot be sustained over a wide range of rotational spees. Besides these vibrations not only perturb the normal operation of a rotating machine, but may also cause serious damage to the machinery system. And, it is really impossible to change one parameter without changing others, or difficult to fabricate the modified non-circular type bearing, with all the other cures used just now, In this study, hybrid bearing with magnetic exciter is designed for stability improvement of hydrodynamic bearing rotor system without changing mechanical parameters. For stability study, eigenvalue study of the bearing-rotor system is executed by finite element method and results of analyses and experiments show the possibilities of the stability improvement of the hydrodynamic bearing system by using the electricmagnetic force.

• 진공이야기
• /
• 제3권4호
• /
• pp.19-23
• /
• 2016

Angle resolved photoemission spectroscopy (ARPES) is a powerful technique which can directly visualize the electronic structure of solid in detail including many-body interaction information. However, ARPES has a certain limitation in applying control parameters such as doping or pressure, which helps to dig out the clue to understand the desired phenomena or the target system. During ARPES experiment, the control parameter is the temperature only. Other parameters especially electric- and magnetic- field cannot be applied. Recently introduced surface-electron doping technique highlights new avenue to overcome such limitation. In this article, starting from introducing basic concepts of ARPES and its current status, the power of new technique will be demonstrated when it is combined to ARPES by introducing recent results on iron based superconductors.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1087-1088
• /
• 2011

영구자석형 전동기는 높은 출력밀도를 가지므로 현재까지 많은 연구가 진행되어 왔다. 일반적으로 매입형 영구자석 동기전동기는 영구자석의 사용량이 많을수록 돌극비를 향상 시킬 수 있으므로 발생토크 성분 중 릴럭턴스 토크의 비중을 키울 수 있다. 이는 토크 발생 시 입력전류를 저감시켜 동손이 감소하고 효율을 증가시키는 효과를 기대할 수 있다. 본 논문에서는 매입형 영구자석 동기전동기의 등가자기회로법를 이용한 설계에 대해 다루고자 한다. 등가자기회로법은 계산시간이 빠르고 전동기 구성인자들의 영향을 신속하게 살펴 볼 수 있으므로 초기설계에 많이 사용된다. 본 논문에서는 등가자기회로법을 이용하여 공극자속밀도를 산정한 후 슬롯을 고려한 relative permeance, 그리고 무부하 역기전력을 산정하고 최종적으로 유한요소법을 이용하여 검증한다.

• 한국정밀공학회지
• /
• 제19권5호
• /
• pp.29-35
• /
• 2002

This study shows the process design and forming analysis of permalloy shielding can that support the automobile multi-display parts to indicate the accurate information of car. This study is particularly important, since the accuracy of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite sensitively. The objective functions are defects such as hemming wind, hemming length, hemming wrap and tightness in prehemming process. The pre-hemming angle is considered as design parameter. The commercial finite element program PAM-STAMP™ was used to simulate the pre-hemming and hemming process. The ANN (Artificial Neural Network) has been implemented for minimizing of objective function and for investigating effect of punch angle relevant to the pre-hemming process. The results of analysis to validate the proposed design method are presented.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2009년도 정기총회 및 추계학술대회 논문집
• /
• pp.96-98
• /
• 2009

This paper propose a method to detect the rotor position of IPMSM(Interior permanent magnet synchronous motor) at standstill without a position sensor. The proposed method is based on current variation caused by the magnetic saturation of stator core as rotor position. By choosing an appropriate voltage vector and applying it to phase winding, it enables the algorithm to discern between a north pole and south pole, and subsequently estimates an absolute position. This method dose not depend on the model of the motor and the motor parameter.