• Title/Summary/Keyword: the waves

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Analysis of stress, magnetic field and temperature on coupled gravity-Rayleigh waves in layered water-soil model

  • Kakar, Rajneesh;Kakar, Shikha
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.111-126
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    • 2015
  • In this study, the coupled effects of magnetic field, stress and thermal field on gravity waves propagating in a liquid layer over a solid surface are discussed. Due to change in temperature, initial hydrostatic stress and magnetic field, the gravity-sound Rayleigh waves can propagate in the liquid-solid interface. Dispersion properties of waves are derived by using classical dynamical theory of thermoelasticity. The phase velocity of gravity waves influenced quite remarkably in the presence of initial stress parameter, magneto-thermoelastic coupling parameter in the half space. Numerical solutions are also discussed for gravity-Rayleigh waves. In the absence of temperature, stress and magnetic field, the obtained results are in agreement with classical results.

Measurement of Coastal Waves using Marine Radar (선박용 레이더를 이용한 연안파 계측)

  • Park, Jun Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.1
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    • pp.83-91
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    • 2018
  • In this paper, usefulness of marine radar for water waves measurement in coastal waters is presented. We installed a marine radar to acquire radar images of water wave around light beacon at Jujeon in Ulsan. Also, a series of analysis procedures for obtaining the wave information from the acquired image is described with a schematic diagram. We compared analysis results of radar images with measurement values using wave height gauge at light beacon. In order to improve accuracy of analysis results, detailed water depth information is essential. In conclusion, in case of the use of radar for water waves measurement, it is shown that it is very necessary to increase the accuracy of measurement by consideration of the water depth in the dispersion relation of water waves.

Separation of Seismic Signals using a Polarization Filter based on the Complex Trace Analysis Method (복소트레이스 분극필터를 이용한 다성분 탄성파자료 신호분리)

  • Kim, Ki-Young;Lee, So-Young
    • Journal of the Korean Geophysical Society
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    • v.8 no.1
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    • pp.35-38
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    • 2005
  • Polarization filtering based on the multicomponent complex trace analysis method is performed to reject Rayleigh waves and to enhance S waves. To test the polarization filter, synthetic seismic data were constructed for a simple two-layer model based on the finite difference method. Rayleigh waves with elliptic motion are eliminated effectively and P and S waves with linear motions are well separated each other.

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A Study of Matimum Run-up Heights of Periodic Waves (주기파의 최대 처오름높이에 관한 연구)

  • Jo, Yong-Sik;Lee, Bong-Hui
    • Journal of Korea Water Resources Association
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    • v.32 no.6
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    • pp.649-655
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    • 1999
  • The maximum run-up heights of periodic waves are numerically investigated in this study. Incident waves are sinusoidal and enoidal waves. The maximum run-up height of enoidal wave approaches that of sinusoidal wave as the wave length decreases, while it approaches that of solitary wave as the wave length increases. If wave height is fixed, the maximum run up heights of enoidal waves are always greater than those of sinusoidal waves but smaller than those of solitary waves.

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Scour around spherical bodies due to long-crested and short-crested nonlinear random waves

  • Myrhaug, Dag;Ong, Muk Chen
    • Ocean Systems Engineering
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    • v.2 no.4
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    • pp.257-269
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    • 2012
  • This paper provides a practical stochastic method by which the maximum equilibrium scour depth around spherical bodies exposed to long-crested (2D) and short-crested (3D) nonlinear random waves can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Forristall (2000) wave crest height distribution representing both 2D and 3D nonlinear random waves, and using the regular wave formulas for scour and self-burial depths by Truelsen et al. (2005). An example calculation is provided.

Separation of Seismic Signals using a Polarization Filter based on the Complex Trace Analysis Method (복소트레이스 분극필터를 이용한 다성분 탄성파자료 신호분리)

  • Kim, Ki-Young;Lee, So-Young
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.233-236
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    • 2005
  • Polarization filtering based on the multicomponent complex trace analysis method is performed to reject Rayleigh waves and to enhance S waves. To test the polarization filter, synthetic seismic data were constructed for a simple two-layer model based on the finite difference method. Rayleigh waves with elliptic motion are eliminated effectively and P and S waves with linear motions are well separated each other.

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Numerical Nonlinear Stability of Traveling Waves for a Chemotaxis Model

  • Min-Gi Lee
    • Kyungpook Mathematical Journal
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    • v.63 no.2
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    • pp.141-154
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    • 2023
  • We study the stability of traveling waves of a certain chemotaxis model. The traveling wave solution is a central object of study in a chemotaxis model. Kim et al. [8] introduced a model on a population and nutrient densities based on a nonlinear diffusion law. They proved the existence of traveling waves for the one dimensional Cauchy problem. Existence theory for traveling waves is typically followed by stability analysis because any traveling waves that are not robust against a small perturbation would have little physical significance. We conduct a numerical nonlinear stability for a few relevant instances of traveling waves shown to exist in [8]. Results against absolute additive noises and relative additive noises are presented.

Modeling of SH-waves in a fiber-reinforced anisotropic layer

  • Kakar, Rajneesh
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.91-104
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    • 2016
  • In this paper we investigate the existence of SH-waves in fiber-reinforced layer placed over a heterogeneous elastic half-space. The heterogeneity of the elastic half-space is caused by the exponential variations of density and rigidity. As a special case when both the layers are homogeneous, our derived equation is in agreement with the general equation of Love wave. Numerically, it is observed that the velocity of SH-waves decreases with the increase of heterogeneity and reinforced parameters. The dimensionless phase velocity of SH-waves increases with the decreases of dimensionless wave number and shown through figures.

Rayleigh waves in nonlocal porous thermoelastic layer with Green-Lindsay model

  • Ismail Haque;Siddhartha Biswas
    • Steel and Composite Structures
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    • v.50 no.2
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    • pp.123-133
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    • 2024
  • The paper deals with the propagation of Rayleigh waves in a nonlocal thermoelastic isotropic layer which is lying over a nonlocal thermoelastic isotropic half-space under the purview of Green-Lindsay model and Eringen's nonlocal elasticity in the presence of voids. The normal mode analysis is employed to the considered equations to obtain vector matrix differential equation which is then solved by eigenvalue approach. The frequency equation of Rayleigh waves is derived and different particular cases are also deduced. The effects of voids and nonlocality on different characteristics of Rayleigh waves are presented graphically.

Conversion of Extraordinary Waves into Upper Hybrid Waves in Inhomogeneous Plasmas

  • Kim, Gyeong-Seop;Kim, Eun-Hwa;Lee, Dong-Hun
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.35-35
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    • 2004
  • Inhomogeneity Is important in wave coupling and mode conversion. We numerically examine the conversion of extraordinary(X) waves into upper hybrid(UH) waves in inhomogeneous plasmas by using a three-dimensional multi-fluid numerical model. A one-dimensional Inhomogeneous density profile is assumed in a cold and collisionless plasma. The density gradient is taken to be perpendicular to the magnetic field. An impulsive input is assumed to excite the X waves in the inhomogeneous box model. (omitted)

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