Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"wave propagations"”.
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Simulation of dynamic on-body wave propagations : comparison with measured values.
… an understanding of electromagnetic (EM) wave propagation behavior on and around the moving human body. This thesis describes research using a phantom body model in CST software to simulate EM wave propagation between antennas mounted on moving humans. The model is directed by body motion …
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A finite element method and the method of finite spheres enriched for analysis of wave propagations
… spheres enriched for the solution of various wave propagation problems. The first part of this thesis is to present an enriched finite element method which is an extension of the procedure introduced by Kohno, Bathe, and Wright for one dimensional problems. Specifically, the novelties are: …
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Contributions to the direct time integration in wave propagation analyses
… to contribute to the computational methods for wave propagations. We review an implicit time integration method, the Bathe method, that remains stable without the use of adjustable parameters when the commonly used trapezoidal rule results in unstable solutions. We then focus on additional …
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A numerical study of wave propagation in poroelastic media by use of the localized differential quadrature (LDQ) method
… been conducted on static problems, the study on wave propagation is of great importance. First in this thesis, the theory of wave propagation in fluid-saturated poroelastic media and the localized differential quadrature (LDQ) method are introduced. Using this LDQ method, the governing equations …
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Numerical Boundary Conditions for the Fourth -Order Accurate Finite -Difference Time -Domain Solution of Maxwell's Equations
… Fang's schemes. Simulations of electromagnetic wave propagations through rectangular waveguides demonstrate that the enhanced high-order schemes produce much smaller phase errors compared to the second-order FDTD methods. As a consequence, the enhanced fourth-order Fang's schemes reduce the …
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Stress Wave Propagation In A ‘Simplified Surrogate Tibia’ Subjected To Blast Loading
… landmine blast scenario. The study of stress wave propagations in the tibia during an anti-vehicle landmine blast aids in scientific understanding of blast injuries produced by anti-vehicle landmines by refining current ideas, discovering novel phenomena, and filling information gaps. This …
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FEM simulation of ultrasonic wave propagation in solid rods
… of this study is to simulate ultrasonic wave propagation in solid cylindrical rods. In this study, both experimental investigations and theoretical analyses are conducted. In the experiment, the 4.2 mm diameter center wire of the commonly used Grad 250 7-wire strand have been employed as …
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ACCURACY IMPROVEMENT OF CABLE HARNESS MODELING & ANALYTICAL MODELING OF MULTI-REFLECTIONS IN HIGH-SPEED SIGNAL CHANNELS
… geometry can be very complicated, making full-wave modeling and simulation approaches computational resource-intensive. To cut down the computational effort, the hybrid multiconductor transmission-line (MTL) method has been developed, and the generalized MTL (GMTL) method and the multiple …
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Effects of tool positions on borehole acoustic measurements : a stretched grid finite difference approach
… algorithm that features non- uniform grid, wavelet-based difference operator and anisotropic perfectly matched layer. This algorithm reduces numerical reflections and wave distortions introduced by grid change to a minimum by sampling the physical space with gradually varying mesh. By …
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Development and applications of new peridynamic models
… mechanics. The model was then used to simulate wave propagations in split Hopkinson's pressure bar (SHPB) and was validated by the experiment results. The peridynamic model was then used for designing required shapers in SHPB application and greatly improves the experiment efficiency. Secondly, …
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DGM-FD: A Finite Difference Scheme Based on the Discontinuous Galerkin Method
<p>Accurate and efficient numerical wave propagation is important in many areas of study such as computational aero-acoustics (CAA). While dissipation and dispersion errors influence the accuracy of a method, efficiency can be assessed by convergence rates and effective adaptability to different …
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Passive Seismic Tomography and Seismicity Hazard Analysis in Deep Underground Mines
… give evidence that velocities of seismic wave propagations increase in high stress areas of rock samples. It is well known that closing effects of cracks under compressive pressures tend to increase the effective elastic moduli of rocks. Tomography can map stress transfer and …
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A study of Benguela Niños and Niñas from 1958 to 2015
… help to define an index of equatorial Kelvin wave activities in the Equatorial Atlantic. There is a good agreement between PIRATA monthly dynamic height anomalies, altimetric monthly sea surface height anomalies (SSHA), and sea level anomalies calculated with an OLM at interannual time scales. …
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Impacts of short-time scale water column variability on broadband high-frequency acoustic wave propagation
… Acoustic signals propagate as pressure wavefronts from a source to a receiver through an ocean medium with variable physical parameters. The water column physical parameters that change acoustic wave propagation in the ocean include temperature, salinity, current, surface roughness, …
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Distributed Modeling Approach for Electrical and Thermal Analysis of High-Frequency Transistors
… at higher frequency bands. In other words, the wave propagation effects and phase velocity mismatches are considered when developing the model. The obtained results from the developed simulation tool are then compared with the measurements and excellent agreement is achieved between the two …