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 “"Bayesian inversion"”.
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Deciphering multiple changes in complex climate time series using Bayesian inference
… and dispersion are employed in the light of Bayesian inversion. In contrast to established Bayesian approaches to multiple changes, the generic approach proposed in this thesis is not formulated in the framework of specialized partition models of high dimensionality requiring prior …
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Impact induced porosity of terrestrial impact craters : a gravity study of Meteor Crater.
… units across Meteor Crater. Finally, we used a Bayesian inversion scheme to infer the bulk density and porosity of each stratigraphic unit. The models reflect the creation of impact-induced porosity of ~5-10% around and beneath the crater, supporting previous findings with novel methods and data.
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Development of techniques for quantifying pressure and saturation changes from 4D seismic data applied to a North Sea field
… to populate the training dataset can improve inversion results considerably. The third method is a stochastic Bayesian inversion that uses reservoir simulation results as prior information, providing estimations to the pressure and saturation changes as well as their related uncertainties. All …
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Regional CO₂ flux estimates for South Africa through inverse modelling
Bayesian inverse modelling provides a top-down technique of verifying emissions and uptake of carbon dioxide (CO₂) from both natural and anthropogenic sources. It relies on accurate measurements of CO₂ concentrations at appropriately placed sites and "best-guess" initial estimates of the biogenic …
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Inversion Analysis of Time-Domain Controlled-Source Electromagnetic Data to Characterize Offshore Freshened Groundwater in the Canterbury Bight, New Zealand, and Offshore Maltese Islands
… interpretation. However, deterministic inversion approaches remain limited in their ability to quantify pore-water salinity and associated uncertainties. This thesis investigates the capability of time-domain (TD) CSEM methods to characterize OFG systems across different geological …
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Stochastic Sea Ice Modeling with the Dynamically Orthogonal Equations
… ocean and sea ice probabilistic modeling, Bayesian inversion, and machine learning are challenging. In this work, we implement a deterministic 2D viscoplastic sea ice solver and derive and implement new sea ice probabilistic models based on the dynamically orthogonal (DO) equations. We …
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Sub-bottom profiling using an Autonomous Underwater Vehicle equipped with a sound source and towed hydrophone array
… speed and layer thickness of the seabed through Bayesian geoacoustic inversion. This method provides range-dependent geoacoustic parameters with a resolution on the order of 10 meters. Numerical studies indicate that, for timing data with low variance, arrival times can be used to accurately …
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Sub-Bottom Profiling Using an Autonomous Underwater Vehicle Equipped With a Sound Source and Towed Hydrophone Array
… speed and layer thickness of the seabed through Bayesian geoacoustic inversion. This method provides range-dependent geoacoustic parameters with a resolution on the order of 10 meters. Numerical studies indicate that, for timing data with low variance, arrival times can be used to accurately …
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Neural Bayesian goal inference for symbolic planning domains
… assistants. This thesis introduces a neural Bayesian approach to goal inference in multiple symbolic planning domains and compares the results of this approach to the results of a recently developed Monte Carlo Bayesian inference method known as Sequential Inverse Plan Search (SIPS). SIPS is …
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Employment of Multi-Source Satellite-Based Observations in Air Quality Modeling over Asia
… a day during the 2022 spring, I performed Bayesian inversion to hourly constrain the NOx emissions. This enabled the model to better capture the diurnal variation in NOx emissions, such as its morning rush hour peak, particularly when more retrievals were available each day, reducing the …
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Electromagnetic Time-Reversal Imaging and Tracking Techniques for Inverse Scattering and Wireless Communications
… and/or conductivity fluctuations, based on Bayesian compressive sensing. Bayesian inversion provides means for estimating the confidence level of the inversion, and for adaptively optimizing subsequent measurements. This technique is applied to a wide range of problems of practical interest …
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Robust Bayesian inference via optimal transport misfit measures: applications and algorithms
… to reliable inference in many problems. In the Bayesian setting, model misspecification can lead to inconsistency as well as overconfidence in the posterior distribution associated with any quantity of interest, i.e., under-reporting of uncertainty. This thesis develops a Bayesian framework to …
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Ground motions and source mechanisms of earthquakes in multiscales : microseismicity to macroseismicity
… as well as their uncertainties, a waveform-based Bayesian moment tensor inversion approach was developed and validated by synthetic tests. The Bayesian approach estimates the source parameters and the uncertainties by generating a posterior probability density function of the source parameters. …
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Timescales of magma residence and transport underneath Iceland
… element numerical model with a nested sampling Bayesian inversion to provide robust uncertainty estimates and account for observations from multiple elements within a single phase, or multiple phases. In this thesis, the DFENS methodology is applied to three eruptions from Iceland with different …
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Mapping the Core-Mantle Boundary Using Sdiff Postcursors
… model – the 2D wavefront tracker (2DWT) – into a Bayesian inversion to better explore the parameter space of these structures and, for the first time, to estimate the associated errors. For the Hawaiian ULVZ, we selected five high quality events with good azimuthal coverage to apply the inversion. …
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The broken non-abelian X-ray transform and inverse problems for connections at high fixed frequency
… its broken non-abelian X-ray transform through Bayesian inversion. The broken non-abelian X-ray transform on an arbitrary Riemannian or Lorentzian manifold is studied in Chapter 3. We show that regardless of the geometry of M, the transform is injective up to gauge if we consider all possible …