• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.21-22
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• 2007

The periodic multilayer is considered as the X-ray reflection mirror. High X-ray reflectivity from the incident angle greater than the grazing critical angle can be obtained by the periodic multilayer structure. The Optical constants are investigated in order to determine the material for X-ray reflection mirror. The X-ray reflection mirror is designed for W, Si using computer simulation. The reflectivity is calculated for various incident angles and ratio of thickness.

• 한국항해학회지
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• 제19권2호
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• pp.99-106
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• 1995

A wide band design method of an electromagnetic wave absorber with square ferrite cylinders in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is also evaluated and proposed for its accuracy by comparison with Hashin-Shtrikman formulas. Based on the developed model, wide band electromagnetic wave absorbers with excellent reflective frequency characteristics in the frequency range of 30MHz to 3, 690MHz were designed.

• Journal of applied mathematics & informatics
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• 제12권1_2호
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• pp.183-198
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• 2003

We highlight the alternative presentation of the Cauchy-Riemann conditions for the analyticity of a complex variable function and consider plane equilibrium problem for an elastic transversely isotropic layer, in finite deformation. We state the fundamental problems and consider traction boundary value problem, as an example of fundamental problem-one. A simple solution of“Lame's problem”for an infinite layer is obtained. The profile of the deformed contour is given; and this depends on the order of the term used in the power series specification for the complex potential and on the material constants of the medium.

• Transactions on Electrical and Electronic Materials
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• 제4권1호
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• pp.11-14
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• 2003

The regularities of immobilization of natural medicinal substances - alchidine on gels of poly(vinyl alcohol) - are investigated. It is shown that the polymer components of alchidine interact with nonionic polymer with formation of interpolymer complexes. The influence of the different factors on the properties of complexes is considered and the constants of alchidine distribution in the system gel - water are calculated.

• Korean Journal of Mathematics
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• 제7권2호
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• pp.245-269
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• 1999

Multigrid method and acceleration by conjugate gradient method for first-order system least squares (FOSLS) using bilinear finite elements are developed for various boundary value problems of planar linear elasticity. They are two-stage algorithms that first solve for the displacement flux variable, then for the displacement itself. This paper focuses on solving for the displacement flux variable only. Numerical results show that the convergence is uniform even as the material becomes nearly incompressible. Computations for convergence factors and discretization errors are included. Heuristic arguments to improve the convergences are discussed as well.

• The Journal of the Acoustical Society of Korea
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• 제12권1E호
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• pp.48-55
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• 1993

초음파 탐촉자의 개발에 필요한 압전재료의 선택을 위하여 탐촉자의 성능에 영향을 미치는 탄성, 유전, 압전 상수의 영향을 알아보았다. 해석 방법으로는 등가회로를 통한 두께 모드 발신기, 수신기, 펄스 반사기의 전달함수를 구하였으며, 이로부터 압전재료의 각 물성치가 가져야 할 바람직한 특성을 제시하였다. 본 연구의 결과는 재료의 선택시와 더불어 세라믹 공학자들이 초음파용 압전소자를 개발함에 있어 적절한 지침이 될 수 있을 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.474-481
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• 1998

Metal bonded rubber spring is used in primary suspension component of the high speed train. The aim of this study is to establish a finite element analysis technique for the metal bonded rubber spring. Some theoretical analyses were performed on the hyperelastic behavior in rubber material and test are carried out to acquire the constants in strain energy function for it. Also, finite element analysis were executed to evaluate the design parameter and behavior of deformation and stress distribution using by the commercial finite element code.

• 한국항해학회지
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• 제18권2호
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• pp.151-158
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• 1994

A wide band design method of an electromagnetic wave absorber using exponentially tapered ferrite, which has very wide band frequency characteristics, is proposed and discussed. The wide band electroma-gnetic wave absorber can be designed by the proposed equivalent material constants method for the re-gions varying spatially in the shape of ferrite. Futhermore, the wide band ferrite electromagnetic wave absorber with taper, which have not only exce-llent reflectivity frequency characteristics but also the band width of 30MHz to 2150 or 2450MHz under the tolerance limits of -20dB reflectivity, were designed.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.109-112
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• 2004

The charged mosaic membranes having cation and anion exchange mixed groups within membrane were researched. The composite charged mosaic membrane was investigated from simultaneous transport such as solute and solvent flux. On the other hand, the reflection coefficient and salt flux coefficient were estimated by taking account of the cross constants of the phenomenological equation.(omitted)

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1996년도 The Korean Institute of Navigation 1996년도 한·중 국제학술 심포지움 및 추계학술발표회 논문집
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• pp.125-134
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• 1996

A design method of double layered electromagnetic wave absorbers with cross-shaped ferrite prominence in the second layer which has broad band frequency characteristics was proposed. The broad band electromagnetic wave absorber can be designed under some approximations by the theoretical model using the equivalent material constants method for the second layer. Based on the developed model broad band electromagnetic wave absorbers with excellent reflectivity frequency characteristics in the frequency range of 30MHz to 3,990MHz were designed.