• 전자공학회논문지A
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• 제30A권2호
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• pp.10-15
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• 1993

The cylindrical TEM mode solution for electromagnetic coupling to an angled two-wire transmission line is corrected by imposing some physical constraints additionally. The validity of the correction process is assured by showing that the corrected solution approaches the numerical result for the equivalent model of cascaded piecewise uniform sections.

• Coupled systems mechanics
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• 제5권3호
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• pp.235-254
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• 2016

A numerical model for fluid-structure interactions (abbr. FSI) is presented in the context of sloshing effects in movable, partially filled tanks to improve understanding of interactions between the fluid and the dynamics of a tank flexibly attached to a vehicle. The purpose of this model is to counteract the penalizing impact of the added mass effect on classical partitioned FSI coupling scheme: the proposed investigation is based on an added mass corrected version of the classical strongly coupled partitioned scheme presented in (Song et al. 2013). Results show that this corrected version systematically allows convergence to the coupled solution. In the rare cases where convergence is already obtained, the corrected version significantly reduces the number of iterations required. Finally, it is shown that the convergence limit imposed by added mass effect for the non-corrected coupling scheme, is directly dependent on the aspect ratio of the fluid domain and highly related to the precision order of the temporal discretization scheme.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.488-503
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• 1999

The present paper considers the constraint effect on J-R curves under the two-parameter $J-A_2$ controlled crack growth within a certain amount of crack extension. Since the parameter $A_2$ in $J-A_2$ three-term solution is independent of applied loading under fully plasticity or large-scale defor-mation $A_2$ is a proper constraint parameter uring crack extension. Both J and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and A2 as a con-straint parameter. Approach of the constraint-corrected J-R curve is proposed and a procedure of transferring the J-R curves determined from standard ASTM procedure to non-standard speci-mens or real cracked structures is outlined. The test data(e.g. initiation toughness JIC and tearing modulus $T_R$) of Joyce and Link(Engineer-ing Fracture Mechanics 1997, 57(4) : 431-446) for single-edge notched bend[SENB] specimen with from shallow to deep cracks is employed to demonstrate the efficiency of the present approach. The variation of $J_{IC}$ and $T_R$ with the constraint parameter $A_2$ is obtained and a con-straint-corrected J-R curves is constructed for the test material of HY80 steel. Comparisons show that the predicted J-R curves can very well match with the experimental data for both deep and shallow cracked specimens over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. The constraint effects of specimen types and specimen sizes on the J-R curves can be easily obtained from the constrain-corrected J-R curves.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.227-230
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• 1999

Rigorous formulation for solving the scattered fields by a lossy dielectric wedge is proposed. By employing the Kirchhoff's integrals in the physical domain and the extinction theorem in the mathematically complementary region, it is shown that the accurate solution is obtained by adding the numerically corrected fields generated by the multipole source expansions to the analytically approximated physical optics solution. Its accuracy is affirmed by the extinction behavior of the solution in the complementary region.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.49-54
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• 2007

오일러나 Navier-Stokes방정식을 통한 터빈 캐스케이드 유동 해석은 비교적 정확한 해를 구할 수 있으나 많은 계산 시간을 필요로 한다. 비점성, 비압축성 유동에 적용이 가능한 패널법은 빠르고 합리적인 유동 정보를 얻을수 있지만 고속 유동의 경우 압축성 보정이 반드시 이뤄져야한다. 본 논문에서는 압축성이 보정된 패널법을 이용하여 터빈 블레이드 표면의 속도 분포를 계산하였다. 그 결과, 압축성이 보정된 패널법의 결과는 실험이나 유한 체적법에 의해 계산된 결과와 잘 일치하였다.

• 한국추진공학회지
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• 제12권1호
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• pp.23-28
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• 2008

오일러나 Navier-Stokes 방정식을 통한 터빈 캐스케이드 유동 해석은 비교적 정확한 해를 구할 수 있으나 많은 계산 시간을 필요로 한다. 비점성, 비압축성 유동에 적용이 가능한 패널법은 빠르고 합리적인 유동 정보를 얻을 수 있지만 고속 유동의 경우 압축성 보정이 반드시 이뤄져야한다. 본 논문에서는 압축성이 보정된 패널법을 이용하여 터빈 블레이드 표면의 속도 분포를 계산하였다. 그 결과, 압축성이 보정된 패널법의 결과는 유한 체적법에 의해 계산된 결과와 잘 일치하였다.

• 한국항공우주학회지
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• 제32권5호
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• pp.58-64
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• 2004

본 논문에서는 양시등급 항공기 동력학에서 빠른 종속시스템의 극점들을 그대로 둔 채 느린 종속시스템의 극점만을 재배치함으로써 페루프의 근사치 해를 획득하는 방법이 제안되었다. 행렬대각화를 통하여 얻어지는 이러한 근사치 해는 수정된 것과 수정되지 않은 것 두 종류로 구분된다. 이들의 차이는 전자의 경우 오차가 $O({\varepsilon})$이며 후자의 경우는 오차가 $O({\varepsilon}^2)$이다. 두 가지 해는 모두 감소해이지만 충분한 견실성을 보여준다. 제안된 기법의 우수성은 항공기 종방향 운동 모델의 시뮬레이션을 통하여 확인되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1984년도 하계학술회의논문집
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• pp.287-291
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• 1984

The electromagnetic wave scattered by an arbitrary-angled dielectric wedge is constructed by physical optics solution and its corrected field. Two models of correction source are obtained; one is multipole line source at tip of wedge and the other is correction electric and magnetic currents distributed along the interfaces of dielectric wedge. Calculated far-field patterns are presented and compared each other.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.187-194
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• 2005

For the analysis of compressible multi-phase and real gas flows, characteristic form of Roe's Riemann solver was derived using real gas equation of state. It was extended to multi component reactive system considering variable specific heat. From this study, it is known that some correction should be made for the use of existing numerical algorithm. 1) Sonic speed and characteristic variable should be corrected with real gas effect. 2) Roe's average was applicable only with the assumption of constant properties. 3) Artificial damping term and characteristic variables should be corrected but their influences may not be significant.

• 대한전자공학회논문지
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• 제25권9호
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• pp.1027-1038
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• 1988

This paper, the last part of these three companion papers treated the electromagnetic diffraction by a dielectric wedge, presents the correction to the physical optics approcomation by the sheet currents of the Neumann expansion. Those expansion coefficients obtained by solving dual series equation amenable to simple numerical calculation may provide the asymprotically corrected solution. The validity of this result, satisfying both the edge condition near the tip of the dielectric wedge and the boundary condition along dielectric interfaces, is assured by approach of the corrected diffraction pattern to that of a perfectly conducting wedge for large permittivity of dielectric wedge.