• Title/Summary/Keyword: 산란체법

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Computation of Wave Transformation over a Multi-Step Topography by a Scatterer Method (산란체법에 의한 다중 계단지형에서의 파랑변형 계산)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.5
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    • pp.439-451
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    • 2008
  • Based on reflected and transmitted waves by a single step bottom, a new model of scatterer method is constructed which can be used to calculate wave transformation over a multi-step topography. The approximate results are tested by comparison with the more accurate results obtained from EFEM presented by Kirby and Dalrymple(1983). In the case of plane-wave approximation, solutions of the scatterer method and the EFEM are the same. Results obtained by the scatterer method with non-propagating modes are much better, in terms of phase for the calculated reflection and transmission coefficients, than those by plane-wave approximation. As the effect of non-propagating modes decreases, solutions of the scatterer method become closer to those of the EFEM.

Wave Propagation Models Due to Topographic Change: Scatterer Method and Transfer Matrix Method (지형변화에 의한 파랑전파모형: 산란체법과 변환행렬법)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.3
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    • pp.163-170
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    • 2010
  • Both scatterer method and transfer matrix method are compared to analyze their characteristics, which are wave propagation models due to topographic change based on plane wave approximation. Results from the scatterer method are closer to the results obtained by the more accurate existing models and it is appraised that the scatterer method gives the clearer explanation about physical process involved in the wave transformation. Since both methods have analytical solutions, in the computational point of view they are very fast and easy to be implemented. Both methods give a good prediction for wave scattering by relatively simple bedform.

Computation of Wave Propagation by Scatter Method Associated with Variational Approximation (변분근사식과 연계된 산란체법에 의한 파랑변형 계산)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.6
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    • pp.553-563
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    • 2008
  • If an arbitrary topography is approximated to a number of vertical steps, both variational approximation and eigenfunction expansion method can be used to compute linear wave transformation over the bottom. In this study a scatterer method associated with variational approximation is proposed to calculate reflection and transmission coefficients. Present method may be shown to be more simple and direct than the successive-application-matrix method by O'Hare and Davies. And Several numerical examples are given which are in good agreement with existing results.

Solution Comparisons of Modified Mild Slope Equation and EFEM Plane-wave Approximation (수정 완경사파랑식과 EFEM 평면파 근사식의 해 비교)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.2
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    • pp.117-126
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    • 2009
  • In order to test the accuracy between the modified mild slope equation (MMSE) without evanescent modes and the plane-wave approximation (PA) of eigenfunction expansion method, various numerical results from both models are presented. In this study, analytical solutions of two models are employed, one based on the MMSE derived by Porter (2003) and the other on the scatterer method of PA by Seo (2008a). Judging from direct comparisons against existing results of rapidly varying topography, the PA model gives better predictions of the wave propagation than the MMSE model.

Application of PSInSAR technique for Monitoring Surface Deformation over Coastal Area of Incheon (인천연안지역의 지표변위 관측을 위한 인공위성 SAR 자료의 활용)

  • Kim, Jun-Su;Park, Sang-Eun;Moon, Woo-Il M.
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.277-280
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    • 2006
  • Many industrial fields were constructed on the reclaimed land which was used to be a tidal land. Because the industrial fields stand on weak basement, they are likely to be influenced by surface subsidence. Therefore, the surface subsidence monitoring is required for civil protection. In this study, a novel method to monitor land displacement, PSInSAR technique, was applied to monitor the land subsidence of Incheon Port, which happened a decade ago. Although the land was reclaimed more than 20 years ago, quite a bit of deformation was observed during six years. The maximum subsidence rate reached to 30 mm/year. JERS-1 data was exploited in this study.

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