• Structural Engineering and Mechanics
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• 제81권5호
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• pp.529-537
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• 2022

The present research is to study the effect of inclined load in a two-dimensional homogeneous orthotropic magneto-thermoelastic solid without energy dissipation with fractional order heat transfer in generalized thermoelasticity with two-temperature. We obtain the solution to the problem with the help of Laplace and Fourier transformations. The field equations of displacement components, stress components and conductive temperature are computed in transformed domain. Further the results are computed in physical domain by using numerical inversion method. The effect of fractional order parameter and inclined load has been depicted on the resulting quantities with the help of graphs.

• Geomechanics and Engineering
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• 제31권5호
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• pp.477-488
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• 2022

Pile composite foundation (PCF) has been commonly applied in practice. Existing research has focused primarily on semi-infinite media having equal pile lengths with little attention given to the effects of inclined bedrock and dissimilar pile lengths. This investigation considers the effects of inclined bedrock on vertical loaded PCF with dissimilar pile lengths. The pile-soil system is decomposed into fictitious piles and extended soil. The Fredholm integral equation about the axial force along fictitious piles is then established based on the compatibility of axial strain between fictitious piles and extended soil. Then, an iterative procedure is induced to calculate the PCF characteristics with a rigid cap. The results agree well with two field load tests of a single pile and numerical simulation case. The settlement and load transfer behaviors of dissimilar 3-pile PCFs and the effects of inclined bedrock are analyzed, which shows that the embedded depth of the inclined bedrock significantly affects the pile-soil load sharing ratios, non-dimensional vertical stiffness N₀/wdE_s, and differential settlement for different length-diameter ratios of the pile l/d and pile-soil stiffness ratio k conditions. The differential settlement and pile-soil load sharing ratios are also influenced by the inclined angle of the bedrock for different k and l/d. The developed model helps better understand the PCF characteristics over inclined bedrock under vertical loading.

• 설비공학논문집
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• 제8권3호
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• pp.375-385
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• 1996

Turbulent flow and heat transfer characteristics around staggered tube banks were studied using the 3-D Navier-Stokes equations and energy equation governing a steady incompressible flow, which were reformulated in a non-orthogonal coordinate system with cartesian velocity components and discretized by the finite volume method with a non-staggered variable arrangement. The predicted turbulent kinetic energy using RNG $k-{\varepsilon}$ model was lower than that of standard $k-{\varepsilon}$ model but showed same result for mean flow field quantities. The prediction of the skin friction coefficient using RNG $k-{\varepsilon}$ model showed better trend with experimental data than standard $k-{\varepsilon}$ model result. The inclined flow showed higher velocity and skin friction coefficient than transverse flow because of extra strain rate ($\frac{{\partial}w}{{\partial}y}$). Also, this was why the inclined flow showed higher local heat transfer coefficient than the transverse flow.

• 한국전자파학회논문지
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• 제18권6호
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• pp.577-583
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• 2007

Schroeder 방식의 QRD(quadratic Residue Diffuser) 구조에서 더욱 진화한 경사진 QRD를 사용하여 전자파 잔향실(reverberation chamber) 내의 전자기장 균일도를 향상시켰다. FDTD(Finite-Difference Time-Domain) 수치 해석방식을 이용하여 $2{\sim}3GHz$ 대역에서의 전자파 잔향실 내의 전자기장의 분포를 해석하였다. QRD 경사 각도의 조절과 경사 방향을 전환하여 전자파 잔향실 내부의 시험 공간에서의 E_x,\;E_y,\;E_z$ 샘플의 표준편차 및 공차가 각각 0.3 dB, 2.5 dB 향상되고 전체적으로 전자기장 분포의 균일성이 확보되었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.97-106
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• 2004

Stability of laminar premixed planar flames inclined in gravitational field which generate vorticity is asymptotically examined. The flame structure is resolved by a large activation energy asymptotics and a long wave approximation. The coupling between hydrodynamics and diffusion processes is included and near-unity Lewis number is assumed. The results show that as the flame is more inclined from the horizontal plane it becomes more unstable due to not only the decrease of stabilizing effect of gravity but also the increase of destabilizing effect of rotational flow. The obtained dispersion relation involves the Prandtl number and shows the destabilizing effect of viscosity. The analysis predicts that the phase velocity of unstable flame wave depends on not only the flame angle but also the Lewis number. For relatively short wave disturbances, still much larger than flame thickness, the most unstable wavelength is nearly independent on the flame angle and the flame can be stabilized by gravity and diffusion mechanism.

• 한국연소학회지
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• 제9권4호
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• pp.9-21
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• 2004

Stability of laminar premixed planar flames inclined in the gravitational field is asymptotically examined. The flame structure is resolved by a large activation energy asymptotics and a long wave approximation. The coupling between hydrodynamics and diffusion processes is included and near-unity Lewis number is assumed. The results show that as the flame is more inclined from the horizontal plane it becomes more unstable due to not only the decrease of stabilizing effect of gravity but also the increase of destabilizing effect of rotational flow. The obtained dispersion relation involves the Prandtl number and shows the destabilizing effect of viscosity. The analysis predicts that the phase velocity of unstable flame wave depends on not only the flame angle but also the Lewis number. For relatively short wave disturbances, still much larger than flame thickness, the most unstable wavelength is nearly independent on the flame angle and the flame can be stabilized by gravity and diffusion mechanism.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.328-333
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• 2003

The purpose of this study is to analyze the impact of shot peening angle on residual stress distribution. From the residual stress analysis of perpendicular shot peening, it could be known that the residual stress in the case of high velocity is larger than low velocity, but the amount of shot size has little effect on the magnitude of compressive residual stress. The centroidal residual stress is not greatly affected by the inclined shot peening but mainly related to the unstable conditions of surface residual stress field. Therefore, this tendency may lead to reduce fatigue life of treated material.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1021-1026
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• 2003

The problem of predicting the fracture strength behavior in orthotropic plate with a crack inclined with respect to the principal material axes is analyzed. Both the load to cause fracture and the crack direction of crack growth arc of interest. The theoretical results based on the normal stress ration theory show significant effects of biaxial loading and the fiber orientation on the crack growth angle and the critical stress. The additional term in the asymptotic expansion of the crack tip stress field appears to provide more accurate critical stress prediction.

• 한국항만학회지
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• 제6권2호
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• pp.25-31
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• 1992

Herein we investigate the mass transport velocity caused by the viscosity near the ocean structure such as circular pile and inclined breakwaters. The mass transport velocity which is represented by the sum of the Eulerian velocity and the stokes drift were derived by Carter, Liu and Mei(1973). The tangential components of the inviscid velocity field at the bottom needed in the calculation of the mass transport velocity is obtained by solving the scattering problem due to breakwaters. The matched asymptotic expansion technique is employed to obtain the inviscid flow fields scattered by inclined breakwaters. The numerical results show that heary sediments tends to be deposited near the center of breakwaters and that the narrowing of the entrance width results in reduction of the magnitude of mass transport.

• 한국지반공학회지:지반
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• 제11권3호
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• pp.91-112
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• 1995

현장타설말뚝기초가 보다 빈번하게 여러가지 구조물의 기초로 쓰이고 있다. 그러나, 경사하중하의 현장타설말뚝의 거동에 대하여는 알려진 사실이 거의 없다. 본 연구에서는, 경사하중을 받는 현장타설말뚝의 비배수거동에 대하여 연구하고자 체계적인 실험을 행하였다. 기초의 직경에 대한 깊이의 비와 하중의 경사도가 같은 변수들을 변화시키면서 행한 연구를 통하여 경사하중에 대한 지지력을 예측하는 반이론적 방법을 개발하였다. 시험변수들은 실제 송전탑건설시 가장 빈번하게 사용되는 대표적인 값들과 같도록 선택되었다. 직경에 대한 말뚝의 깊이비(D/B)가 서로 다른 짧은 강체말뚝에 대하여 논하였으며, 축방향 인발, 경사 인발, 그리고 경사 압축등과 같은 하중상태에 대하여 연구하였다. 경사지지력을 구조상호작용 방정식과 본 실험연구에서 개발한 공식을 사용하여 평가하여 보았다. 본 연구에서 개발한 새로운 공식은 실험실 시험치와, 제한적이나마, 현장의 실제시험치에 적용될 수 있음을 알 수 있었다.