• Journal of Ocean Engineering and Technology
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• v.18 no.2
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• pp.18-24
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• 2004

In this study, the Mild slope equation is extended to both rapidly varying topography and nonlinear waves, using the Hamiltonian principle. It is shown that this equation is equivalent to the modified mild-slope equation (Kirby and Misra, 1998) for small amplitude wave, and it is the same form with the nonlinear mild-slope equation (Isobe, 1994) for slowly varying bottom topography. Comparing its numerical solutions with the results of some hydraulic experiments, there is good agreement between them.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.4
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• pp.181-189
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• 2000

A weakly nonlinear mild-slope equation has been derived directly from the continuity equation with the aid of the Galerkin's method. The equation is combined with the momentum equations defined at the mean water level. A single component model has also been obtained in terms of the surface displacement. The linearized form is completely identical with the time-dependent mild-slope equation proposed by Smith and Sprinks(1975). For the verification purposes of the present nonlinear model, the degenerate forms were compared with Airy(1845)'s non-dispersive nonlinear wave equation, classical Boussinesq equation, andsecond¬order permanent Stokes waves. In this study, the present nonlinear wave equations are discretized by the approximate factorization techniques so that a tridiagonal matrix solver is used for each direction. Through the comparison with physical experiments, nonlinear wave model capacity was examined and the overall agreement was obtained.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.72-77
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• 2003

In this study, Mild slope equation is extended to both of rapidly varying topography and nonlinear waves in a Hamiltonian formulation. It is shown that its linearzed form is the same as the modified mild-slope equation proposed by Kirby and Misra(1998) And assuming that the bottom slopes are very slowly, it is the equivalent with nonlinear mild-slope equation proposed by Isobe(]994) for the monochromatic wave. Using finite-difference method, it is solved numerically and verified, comparing with the results of some hydraulic experiments. A good agreement between them is shown.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.1
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• pp.39-44
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• 2009

To improve the accuracy of numerical simulation of wave trans- formation across the surf zone, nonlinear shoaling effect based on Shuto's empirical formula and breaking mechanism are induced in the elliptic modified mild slope equation. The variations of shoaling coefficient with relative depth and deep water wave steepness are successfully reproduced and show good agreements with Shuto's formula. Breaking experiments show larger wave height distributions than linear model due to nonlinear shoaling but breaking mechanism shows a little bit larger damping in 1/20 beach slope experiment.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2000.09a
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• pp.103-112
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• 2000

Early efforts to model wave transformation from offshore to inshore were based on the ray theory which accounts for wave refraction due to changes in bathymetry and the diffraction effects were ignored. Prediction of nearshore waves with the combined effects of refraction and diffraction as well as reflection has taken a new dimension with the use of the mild-slope equation and the Boussinesq equation. (omitted)

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.138-143
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• 2001

Based on mild slope equation and parabolic approximation the forward diffraction of monochromatic waves by a straight breakwater are studied numerically. The characteristics and effects of stem wave along breakwater and the relations between the stem wave and incident wave angle are discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.1
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• pp.46-55
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• 2001

An approach using the nonlinear wave model in predicting wave-induced currents is presented. The model results were compared with those of the conventional model using phase-averaged radiation stress, and in addition with experimental data captured by a PIV system. As a result of comparison of wave-induced currents generated behind the surface-piercing breakwater and submerged breakwater, eddy patterns appeared to be similar each other but in general numerical solutions of both models were underestimated.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.32-37
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• 2003

In this paper, finite element method is applied for the numerical analysis of wave height distribution. The mild-slope equation is used as the basic equation. The key of this model is to impose the effect of nonlinear waves. Numerical results are presented and agreed well with the results from experimental measurements and other numerical analysis. The present method to determine wave height distribution can be broadly utilized for the analysis of new harbor and port designs in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.2
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• pp.164-173
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• 1994

A numerical model to solve mild slope equation is developed by use of a preconditioned conjugate gradient method (PCGM). In the present paper. accurate boundary conditions and a better preconditioner are employed which are improved from the existing method of Panchang et al. (1991). Computational procedures are focused on weakly nonlinear waves, and emerged problems to make a more accurate model are discussed. The results of model are tested against laboratory results of both circular and elliptic shoals. Model results of wave amplitude show excellent agreement with laboratory data and thes thus model can be used as a powerful tool to calculate wave transformation in shallow waters with complex bathymetry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.307-313
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• 2008

Tidal amplification by construction of sea-dike and sea-walls had been detected not only near Mokpo North Harbor but also at Chungkye Bay which is connected with Mokpo North Harbor by a narrow channel. This brings about increase of tidal flat area and in particular increase of runup height and inundation area during storms. In this study, a simulation process is composed of wind wave generation model for large area and wave inundation model for small coastal zone. The nonlinear version of mild-slope equation is modified for simulating wind-driven surge and wave inundation at a small area. The models are applied to Chungkye Bay, and possible inundation features at Mokpo North Harbor are investigated.