Results 21 to 30 of about 803 (199)
Georesursy, 2018 In sedimentary basin, elastic anisotropy can be described by a transverse isotropic medium and the attenuation in the seismic bandwidth can be approximated by a quasi-constant quality factor.
C. Barnes, M. Charara
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A Reflectivity Guided Elastic Full Waveform Inversion
Recent Advances in Exploration Geophysics, 2014 Full waveform inversion (FWI) produces subsurface images by minimizing the misfit between observed data and calculated model using iterative local optimization algorithms like conjugate gradient method. This approach requires a starting model which should appear in the neighborhood of the global solution of the FWI problem to ensure that the modeled ...
E.J. Hondori, H. Mikada, Eiichi ASAKAWA
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Constrained Full Waveform Inversion for Borehole Multicomponent Seismic Data
Geosciences, 2019 Full-waveform inversion for borehole seismic data is an ill-posed problem and constraining the problem is crucial. Constraints can be imposed on the data and model space through covariance matrices. Usually, they are set to a diagonal matrix.
Marwan Charara, Christophe Barnes
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Progress and prospect of surface-wave imaging techniques in near-surface applications
地球与行星物理论评, 2022 Elastic properties of near-surface materials and their effects on seismic wave propagation are of fundamental interest in groundwater, engineering, and environmental studies. Shear-wave velocity is used to determine 'stiffness', one of the key properties
Limin Wang +3 more
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Case studies of ultrasonic full waveform inversion for inspecting concrete structures
e-Journal of Nondestructive TestingThe non-destructive evaluation of reinforced pre-stressed concrete structures is critical to prevent catastrophic failures of aging infrastructure. Conventional non-destructive inspection methods often rely on manual and subjective interpretation of the
David Sollberger +5 more
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Seismic Waveform Inversion Using the Finite-Difference Contrast Source Inversion Method
Journal of Applied Mathematics, 2014 This paper extends the finite-difference contrast source inversion method to reconstruct the mass density for two-dimensional elastic wave inversion in the framework of the full-waveform inversion.
Bo Han +3 more
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Recent Advances in the GPR Detection of Grouting Defects behind Shield Tunnel Segments
Remote Sensing, 2021 Injecting grout into the gaps between tunnel shield segments and surrounding rocks can reduce ground subsidence and prevent ground water penetration. However, insufficient grouting and grouting defects may cause serious geological disasters.
Ming Peng +5 more
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Journal of Marine Science and EngineeringElastic full waveform inversion (EFWI) is a crucial technique for retrieving high-resolution multi-parameter information. However, the lack of low-frequency components in seismic data may induce severe cycle-skipping phenomena in elastic full waveform ...
Shaobo Qu +4 more
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High-Accuracy Simulation of Rayleigh Waves Using Fractional Viscoelastic Wave Equation
Fractal and Fractional, 2023 The propagation of Rayleigh waves is usually accompanied by dispersion, which becomes more complex with inherent attenuation. The accurate simulation of Rayleigh waves in attenuation media is crucial for understanding wave mechanisms, layer thickness ...
Yinfeng Wang +4 more
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Using Perfectly Matched Layer in a GPU simulation of ultrasound NDT
Research and Review Journal of Nondestructive Testing, 2023 Full Waveform Inversion (FWI) is a state-of-the-art method of image reconstruction with promising results for seismology and NDT. FWI estimates the velocity of wave propagation along the inspected object by iteratively comparing acquired data with ...
Felipe Derewlany Gutierrez +5 more
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