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 16 of 16 for “"Seismic signal"”.
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Sparse seismic signal processing using adaptive dictionaries
Seismic surveys have become the primary measurement tool of exploration geophysics, both onshore and offshore, with significant signal processing needed to estimate the properties of earth subsurface via seismic wave propagation. The typical workflow for seismic includes three phases: acquisition, …
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Acoustic and seismic signal processing for footsetp detection
… of detecting footsteps using acoustic and seismic sensors is approached from three different angles in this thesis. First, accelerometer data processing systems are designed to make footsteps more apparent to a human operator listening to accelerometer recordings. These systems work by …
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Non destructive structure evaluation : an application of seismic signal analysis
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1993.
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Analysis of the repeatability of time-lapse 3D VSP multicomponent surveys, Delhi field
… monitor the CO2 sweep efficiency, time-lapse 3D seismic data have been acquired in this area. Time-lapse studies are increasingly used to evaluate changes in the seismic response induced by the production of hydrocarbons or the injection of water, CO2 or steam into a reservoir. A 4D seismic …
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Automatic First Break Detection by Spectral Decomposition Using Minimum Uncertainty Wavelets
Seismic Signal Processing can be effectively utilized to determine micro- seismic events. With the advances in hydraulic fracturing techniques, first break detection has become really important in locating micro-seismic events. The measured data collected gathers far more information than can be …
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INSIGHTS INTO ERUPTION DYNAMICS AND SHALLOW PLUMBING SYSTEM OF MT. ETNA BY INFRASOUND AND SEISMIC SIGNALS
… the earth and the atmosphere, thus, beside seismic signal, acoustic waves mainly in the range of infrasound are generated. In particular, infrasound activity is usually evidence of open conduit conditions and its quantification can provide information on explosive phenomena and source …
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A Comparative Case Study of Reflection Seismic Imaging Method
… on the earth interior. The quality of seismic images is highly variable depending on the complexity of the underground and on how seismic data are acquired and processed. One of the crucial steps in this process, especially in layered sequences with complicated structure, is the time …
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Automated Vehicle Detection and Classification using Acoustic and Seismic Signals
… describes an investigation into acoustic and seismic methods for achieving such a system specifically for commercial road vehicles. Accurate algorithms have been developed for recognition of moving vehicles using fusion of acoustic and seismic signals. It has been found that seismic signals …
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Seismic ground-roll separation using sparsity promoting L1 minimization
… noise generated by surface waves in land based seismic is a prerequisite to imaging the subsurface. These surface waves, termed as ground roll, overlay important reflector information in both the t-x and f-k domains. Standard techniques of ground roll removal commonly alter reflector information …
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Towards Improved Volcano Monitoring via Automatic Classification of Continuous Tremor
… to detect previously unknown patterns in volcano-seismic signals. Some of these patterns may be precursors to eruption, or change of volcanic activity state. This is particularly interesting for ‘wet’ volcanic systems such as Whakaari (White Island), which regularly produce steam-explosions that …
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Theory and application of source independent full wavefield elastic converted phase seismic imaging and velocity analysis
The recorded seismic signal contains full information about the source that generated the seismic waves and the path along which the seismic waves travel and interfere with subsurface. However, source information is not an explicit part of the seismic record and thus is a large source of …
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Numerical modeling, suppression, and imaging of elastic wave scattering by near-surface heterogeneities
… topography present major challenges to land seismic data acquisition and processing. These challenges can severely affect data quality and introduce uncertainty into reservoir imaging and characterization. The primary objectives of this thesis are to model and study the contribution of …
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Pressure estimation using time-lapse seismic in compacting reservoirs
… in compacting reservoirs. The time-lapse seismic signal in these types of reservoirs results from the combination of pressure depletion, rock compaction and stress redistribution within the reservoir and throughout the surrounding rocks. Simulations using iterative coupling are performed …
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Machine Learning and Bayesian Statistics for Seismic Compressive Sensing
Seismic surveys involve an artificial source of waves and a grid of receivers at the surface. Often, receivers could be missing either because they malfunctioned or could not be placed in certain locations. It could also be the fact that a local source of noise renders a receiver’s output as …
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Microseism analysis during extreme weather events: Medicanes case studies and development of sea state monitoring system based on machine learning algorithms [Analisi del Microseism durante eventi meteorologici estremi: Medicanes casi studio e sviluppo di un sistema di monitoraggio dello stato del mare basato su algoritmi di Machine Learning]
In questa tesi, è stata esplorata la relazione tra il microseism (il segnale sismico più continuo e onnipresente sulla Terra, considerato fino a circa la metà del XIX secolo come un disturbo da scartare), lo stato del mare e l'attività ciclonica nell'area del Mar Mediterraneo mai analizzata …
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Numerical simulations of magma chamber dynamics at Campi Flegrei, and associated seismicity, deformation and gravity changes
… ground slow movement (bradyseism) with high seismicity. This activity, with the high people density and the presence of military and industrial buildings, makes Campi Flegrei one of the areas with higher volcanic hazard in the world. In such a context my thesis has been focused on magma …