• 전기학회논문지
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• 제57권3호
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• pp.390-397
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• 2008

Permanent Magnet Linear Synchronous Motor (PMLSM) has high efficiency, high energy density, and high control-ability. But, the detent force always is produced by the structure of slot-teeth. There are the disadvantages such as noise and vibration of the apparatuses are induced and the control ability is curtailed because detent force acts as thrust ripple. Therefore, the detent force reduction is an essential requirement in PMLSM. Generally, the method, skewing permanent magnet or slot-teeth, is used to reduce the detent force. But the thrust is decreased at the same time. If permanent magnet is skewed, the lateral force which operates as the perpendicular direction of skew direction is generated in linear guide of PMLSM. So, V-skew model is proposed for the reduction of lateral force. The lateral force acts as braking force in linear motion guide, and it has bad influence to the characteristics of PMLSM. However, these problems will not be solved by 2-dimensional Finite Element Analysis (FEA). So, in this paper 3-dimensional FEA is applied to analyze the PMLSM where permanent magnet is skewed and has overhang. The detent force and thrust characteristics considering skew and overhang effects of permanent magnet are analyzed by 3-dimensional FEA and the results are compared with experimental values to verify the propriety of analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1021-1022
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• 2007

By enforcing skew of permanent magnet, detent force decreases, but lateral force that acts for vertical direction of moving direction occurs. This force deteriorates various performance of PMLSM as that acts to friction force between mover and LM guide. Therefore, in this paper, V skew model is proposed for lateral force's reduction and simulation results are compared to experimental value.

• Structural Engineering and Mechanics
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• 제71권6호
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• pp.657-668
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• 2019

The numerical thermal frequency responses of the skew sandwich shell panels structure are investigated via a higher-order polynomial shear deformation theory including the thickness stretching effect. A customized MATLAB code is developed using the current mathematical model for the computational purpose. The finite element solution accuracy and consistency have been checked via solving different kinds of numerical benchmark examples taken from the literature. After confirming the standardization of the model, it is further extended to show the effect of different important geometrical parameters such as span-to-thickness ratios, aspect ratios, curvature ratios, core-to-face thickness ratios, skew angles, and support conditions on the frequencies of the sandwich composite flat/curved panel structure under elevated temperature environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.134-137
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• 2007

By enforcing skew of permanent magnet, detent force decreases, but lateral force that acts for vertical direction of moving direction occurs. This force deteriorates various performance of PMLSM as that acts to friction force between mover and LM guide. Therefore, in this paper, V skew model is proposed for lateral force's reduction and simulation results are compared to experimental value.

• Steel and Composite Structures
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• 제34권2호
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• pp.279-288
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• 2020

The computational post-buckling strength of the tilted sandwich composite shell structure is evaluated in this article. The computational responses are obtained using a mathematical model derived using the higher-order type of polynomial kinematic in association with the through-thickness stretching effect. Also, the sandwich deformation behaviour of the flexible soft-core sandwich structural model is expressed mathematically with the help of a generic nonlinear strain theory i.e. Green-Lagrange type strain-displacement relations. Subsequently, the model includes all of the nonlinear strain terms to account the actual deformation and discretized via displacement type of finite element. Further, the computer code is prepared (MATLAB environment) using the derived higher-order formulation in association with the direct iterative technique for the computation of temperature carrying capacity of the soft-core sandwich within the post-buckled regime. Further, the nonlinear finite element model has been tested to show its accuracy by solving a few numerical experimentations as same as the published example including the consistency behaviour. Lastly, the derived model is utilized to find the temperature load-carrying capacity under the influences of variable factors affecting the soft-core type sandwich structural design in the small (finite) strain and large deformation regime including the effect of tilt angle.

• 방송공학회논문지
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• 제19권5호
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• pp.726-735
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• 2014

최근 초고화질(UHD) 영상시스템의 출현으로 인해 고해상도, 대용량의 4K-UHD급 LCD TV 신호 전송은 높은 해상도와 데이터 확장에 따른 케이블 및 커넥터 수의 증가로 서로 다른 케이블 간의 EMI, 스큐(Skew) 문제로 시스템 구현에 한계가 있다. 차세대 V-by-One HS 인터페이스는 초고해상도 영상처리 IC 및 TCON 간의 새로운 인터페이스 기술로써 600Mbps에서 3.75Gbps의 다양한 데이터 속도로 효율적인 전송이 가능하여 한계를 극복할 수 있다. 본 논문에서는 V-by-One HS IBIS(Input/Output Buffer Information Specification) 모델 시뮬레이션을 통하여 주파수 공진모드의 전압 분포와 PCB 설계 방법을 제안하고 고속영상 신호에 대한 신호 무결성의 검증 방법을 제안하였다.

• Journal of the Optical Society of Korea
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• 제19권2호
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• pp.136-143
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• 2015

Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existing point spread function (PSF) models in the literature corresponding to lens aberrations and defocus are either parameterized and spatially invariant or spatially varying but discretely defined. In this paper, a parameterized model is developed and presented for a PSF which is spatially varying due to lens aberrations and defocus in an imaging system. The model is established from the Seidel third-order aberration coefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometry structure. The accuracy of the model is demonstrated with simulations and measurements for a defocused infrared camera and a single spherical lens digital camera. Compared with optical software Code V, the visual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model.