• Structural Engineering and Mechanics
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• 제53권6호
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• pp.1201-1214
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• 2015

This paper introduces the combined effect of electric field, magnetic field and thermal field on edge wave propagating in a homogeneous isotropic prestressed plate of finite thickness and infinite length. The dispersion relation of edge wave has been obtained by using classical dynamical theory of thermoelasticity. The phase velocity has been computed and shown graphically for various initial stress parameter, electro-magneto parameter, electric parameter and thermoelastic coupling parameter.

• 대한전기학회논문지
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• 제34권1호
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• pp.38-43
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• 1985

Since the superconductor type II with high critical current and high critical magnetic field was discovered in 1961, there were many studies on the superconducting coil for high field and highly homogeneous field. The graphical method and the numerical method by Newton Raphson technique have been studied as the method for design of homogeneous superconducting coil. It is comparatively easy to get a compensating coil for any given main coil by the above methods, but it is too laborious to get a general solution for main coil dimension. This paper studies the optimal design method for minimum volume of superconducting coil under certain central field and highly homogeneous field. The present method makes use of the nonlinear programming for optimization. The optimal solution of NMR superconducting coils by this method are demonstrated very well.

• 충청수학회지
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• 제24권4호
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• pp.825-832
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• 2011

In this paper, we make a minute and detailed proof of a part which is omitted in the process of obtaining the value of the curvature tensor for an invariant affine connection at the point {H} of a reductive homogeneous space G/H in the paper 'Invariant affine connections on homogeneous spaces' by K. Nomizu.

• 대한의용생체공학회:의공학회지
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• 제43권6호
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• pp.369-374
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• 2022

Purpose: Focused ultrasound is an emerging technology for treating the brain locally in a noninvasive manner. In this study, we have investigated the influence of skull properties on simulating transcranial pressure field. Methods: A 3D computational model of transcranial focused ultrasound was constructed using female and male CT data to solve for intracranial pressure. For heterogeneous model, the acoustic properties were calculated from CT Hounsfield units based on a porosity. The homogeneous model assigned constant acoustic properties for the single-layered skull. Results: A computational model was validated against empirical data. The homogeneous models were then compared with the heterogeneous model, resulted in 10.87% and 7.19% differences in peak pressure for female and male models respectively. For the focal volume, homogeneous model demonstrated more than 94% overlap compared with the heterogeneous model. Conclusion: Homogeneous model can be constructed using MR images that are commonly used for the segmentation of the skull. We propose the possibility of the homogeneous model for the simulating transcranial pressure field owing to comparable focal volume between homogeneous model and heterogeneous model.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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• pp.73-76
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• 1999

Superconductors are dissipative when exposed to time-varying magnetic fields. To analyze the AC characteristics of the superconductor, one usually needs to know magnetization curves of it. A good magnetization curves can be obtained only in a homogeneous magnetic field. In this paper, we report the fabrication and test results of a homogeneous magnet, which aims to give background magnetic fields for the superconductor.

• 대한수학회보
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• 제56권1호
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• pp.253-263
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• 2019

Let M be a curvature homogeneous or ball-homogeneous non-$coK{\ddot{a}}hler$ almost $coK{\ddot{a}}hler$ 3-manifold. In this paper, we prove that M is locally isometric to a unimodular Lie group if and only if the Reeb vector field ${\xi}$ is an eigenvector field of the Ricci operator. To extend this result, we prove that M is homogeneous if and only if it satisfies ${\nabla}_{\xi}h=2f{\phi}h$, $f{\in}{\mathbb{R}}$.

• 대한전기학회논문지
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• 제37권8호
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• pp.521-527
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• 1988

At present superconducting magnets have been feasible for many applications which require high field or highly homogeneous field that it is too difficult to be produced by conventional electromagnets. This paper is a stuny on Donble Helmholtz superconducting magnet and newly configurated superconducting magnet that realize highly homogeneous field with the minimum magnet volume. Nonlinear programming method is effectively used for the minimum volume of superconducting magnet that realizes the desired field intensity and high homogeneity. The results on Double Helmholtz and newly configurated superducting magnets that are presented in this paper are largely improved.

• 전기전자학회논문지
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• 제7권2호
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• pp.218-222
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• 2003

전자파 방사 및 측정 시험설비로 표준 시험장인 야외시험장을 사용하고 있으나 시험장 구축의 어려움으로 이를 대체할 수 있는 대용시험장을 사용하여 측정시험을 할 수 있도록 하고 있다. 본 논문에서는 최적화된 측정시스템을 구성하기 위한 대용시험시설인 GTEM CELL(Gigahertz Transverse Electro Magnetic Cell)의 구조분석 및 설계를 하기 위하여 내부도체(Septum)의 넓이 및 두께 변화에 따른 내부도체의 특성임피던스 변화를 살펴보았다.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1575-1579
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• 1999

Embedded processors often accommodate two instruction sets, a standard instruction set and a compressed instruction set. With the compressed instruction set, code size can be reduced while instruction count (and consequently execution time) can be increased. To achieve code size reduction without significant increase of execution time, this paper proposes a new compressed instruction set architecture, called TOE (Two Operations Execution). The proposed instruction set format includes the parallel bit that indicates an instruction can be executed simultaneously with the next instruction. To add the parallel bit, TOE instruction format reduces the destination register field. The reduction of the register field limits the number of registers that are accessible by an instruction. To overcome the limited accessibility of registers, TOE adapts non-homogeneous register partition in which registers are divided into multiple subsets, each of which are accessed by different groups of instructions. With non-homogeneous registers, each instruction can access only a limited number of registers, but an entire program can access all available registers. With efficient non-homogeneous register allocator, all registers can be used in a balanced manner. As a result, the increase of code size due to register spills is negligible. Experimental results show that more than 30% of TOE instructions can be executed in parallel without significant increase of code size when compared to existing Thumb instruction set.

• Structural Engineering and Mechanics
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• 제54권1호
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• pp.135-148
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• 2015

The present investigation is concerned with a study effect of magnetic field and non-homogenous on the elastic stresses in rotating orthotropic infinite circular cylinder. A certain boundary conditions closed form stress fields solutions are obtained for rotating orthotropic cylinder under initial magnetic field with constant thickness for three cases: (1) Solid cylinder, (2) Cylinder with a circular hole at the center, (3) Cylinder mounted on a circular rigid shaft. Analytical expressions for the components of the displacement and stress fields in different cases are obtained. The effect of rotation and magnetic field and non-homogeneity on the displacement and stress fields are studied. Numerical results are illustrated graphically for each case. The effects of rotating and magnetic field and non-homogeneity are discussed.