• Title/Summary/Keyword: Half space

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HALF LIGHTLIKE SUBMANIFOLDS OF A SEMI-RIEMANNIAN SPACE FORM WITH A SEMI-SYMMETRIC NON-METRIC CONNECTION

  • Jin, Dae Ho
    • The Pure and Applied Mathematics
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    • v.21 no.1
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    • pp.39-50
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    • 2014
  • In this paper, we study screen quasi-conformal irrotational half lightlike submanifolds M of a semi-Riemannian space form $\tilde{M}(c)$ admitting a semi-symmetric non-metric connection, whose structure vector field ${\zeta}$ is tangent to M. The main result is a classification theorem for such Einstein half lightlike submanifolds of a Lorentzian space form admitting a semi-symmetric non-metric connection.

Estimation of Shear-Wave Velocities of Layered Half-Space Using Full Waveform Inversion with Genetic Algorithm (유전 알고리즘을 활용한 완전파형역산 기법의 층상 반무한 지반 전단파 속도 추정)

  • Lee, Jin Ho;Lee, Se Hyeok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.4
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    • pp.221-230
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    • 2021
  • This paper proposes full waveform inversion (FWI) for estimating the physical properties of a layered half-space. An FWI solution is obtained using a genetic algorithm (GA), which is a well-known global optimization approach. The dynamic responses of a layered half-space subjected to a harmonic vertical disk load are measured and compared with those calculated using the estimated physical properties. The responses are calculated using the thin-layer method, which is accurate and efficient for layered media. Subsequently, a numerical model is constructed for a layered half-space using mid-point integrated finite elements and perfectly matched discrete layers. An objective function of the global optimization problem is defined as the L2-norm of the difference between the observed and estimated responses. A GA is used to minimize the objective function and obtain a solution for the FWI. The accuracy of the proposed approach is applied to various problems involving layered half-spaces. The results verify that the proposed FWI based on a GA is suitable for estimating the material properties of a layered half-space, even when the measured responses include measurement noise.

Finite Element Analysis of Subsurface Crack Propagation in Half-space Due to Sliding Contact (유한요소법을 이용한 미끄럼 접촉시의 반무한체 내의 수평균열 전파해석)

  • 이상윤;김석삼
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.297-302
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    • 1999
  • Finite element analysis is peformed about the crack propagation in half-space due to sliding contact. The analysis is based on linear elastic fracture mechanics and stress intensity factor concept. The crack location is fixed and the friction coefficient between asperity and half-space is varied to analyze the effect of surface friction on stress Intensity factor for horizontal crack. The crack propagation direction is predicted based on the maximum range of shear and tensile stress intensity factor.

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WEIGHTED HARMONIC BERGMAN FUNCTIONS ON HALF-SPACES

  • Koo, HYUNGWOON;NAM, KYESOOK;YI, HEUNGSU
    • Journal of the Korean Mathematical Society
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    • v.42 no.5
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    • pp.975-1002
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    • 2005
  • On the setting of the upper half-space H of the Eu­clidean n-space, we show the boundedness of weighted Bergman projection for 1 < p < $\infty$ and nonorthogonal projections for 1 $\leq$ p < $\infty$ . Using these results, we show that Bergman norm is equiva­ lent to the normal derivative norms on weighted harmonic Bergman spaces. Finally, we find the dual of b$\_{$^{1}$.

HARMONIC CONJUGATES OF WEIGHTED HARMONIC BERGMAN FUNCTIONS ON HALF-SPACES

  • Nam, Kye-Sook;Yi, Heung-Su
    • Communications of the Korean Mathematical Society
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    • v.18 no.3
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    • pp.449-457
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    • 2003
  • On the setting of the upper half-space of the Euclidean space $R^{n}$, we show that to each weighted harmonic Bergman function $u\;\epsilon\;b^p_{\alpha}$, there corresponds a unique conjugate system ($upsilon$_1,…, $upsilon_{n-1}$) of u satisfying $upsilon_j{\epsilon}\;b^p_{\alpha}$ with an appropriate norm bound.

Half-space albedo problem for İnönü, linear and quadratic anisotropic scattering

  • Tureci, R.G.
    • Nuclear Engineering and Technology
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    • v.52 no.4
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    • pp.700-707
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    • 2020
  • This study is concerned with the investigation of the half-space albedo problem for "İnönü-linear-quadratic anisotropic scattering" by the usage of Modified FN method. The method is based on Case's method. Therefore, Case's eigenfunctions and its orthogonality properties are derived for anisotropic scattering of interest. Albedo values are calculated for various linear, quadratic and İnönü anisotropic scattering coefficients and tabulated in Tables.