Дисертації з теми "Inversion uncertainty"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-20 дисертацій для дослідження на тему "Inversion uncertainty".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
White, Jeremy. "Computer Model Inversion and Uncertainty Quantification in the Geosciences." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5329.
Повний текст джерелаJokinen, J. (Jarkko). "Uncertainty analysis and inversion of geothermal conductive models using random simulation methods." Doctoral thesis, University of Oulu, 2000. http://urn.fi/urn:isbn:9514255909.
Повний текст джерелаThurin, Julien. "Uncertainties estimation in Full Waveform Inversion using Ensemble methods." Thesis, Université Grenoble Alpes, 2020. https://tel.archives-ouvertes.fr/tel-02570602.
Повний текст джерелаFull Waveform Inversion (FWI) is an ill-posed non-linear inverse problem, aiming at recovering detailed pictures of subsurface physical properties, which are crucial to explore and understand Earth structures.Classically formulated as a least-squares optimization scheme, FWI yields a single subsurface model amongst an infinite possibility of solutions. With the general lack of systematic and scalable uncertainty estimation, this formulation makes interpretation of FWI's outcomes complex.In this thesis, we propose an unconventional, scalable way of tackling the lack of uncertainty estimation in FWI, thanks to data assimilation ensemble methods. We develop a scheme combining both classical FWI and the Ensemble Transform Kalman Filter, that we call ETKF-FWI, and which is successfully applied on two 2-D test cases. This scheme takes advantage of the theoretical common-ground between least-squares optimization problems and Bayesian filtering. We use it to recast FWI in a local Bayesian inference framework, thanks to the ensemble representation. The ETKF-FWI provides high-resolution subsurface tomographic models and yields a low-rank approximation of the posterior covariance, holding the uncertainty and resolution information of the proposed solution. We show how the ETKF-FWI can be applied to qualitatively evaluate uncertainty and resolution of the solution. Instead of providing a single solution, the filter yields an ensemble of models, from which statistical information can be inferred.Uncertainty is evaluated from the ensemble's variance, which relates to the diversity of solution amongst the ensemble members for each parameter. We show that lines of the correlation matrix are ideal to evaluate qualitatively parameters resolution, thanks to their adimentionality. While the methodology is computationally intensive, it has the benefit of being fully scalable. Its applicability is demonstrated on a synthetic benchmark. This preliminary test allows us to assess the sensitivity of the ensemble representation to the common undersampling bias encountered in ensemble data assimilation. While undersampling does not affect the image reconstruction in any way, it results in variance underestimation, which makes the whole exercise of quantitative uncertainty assessment complicated. Ensemble inflation has been used to mitigate this bias, but does not seems to be a practical solution.A field data experiment is also discussed in this thesis. It makes it possible to test the sensitivity of the ETKF-FWI to complex noise structure and realistic physics. As it stands, the complexity of the problem reduces flexibility in the ensemble generation, and hence on the uncertainty estimate. Despite these limitations, results are consistent with the synthetic benchmark, and we are able to provide a qualitative uncertainty assessment. The field data case also allows us to evaluate the possibilities to use the ETKF-FWI on multiparameter inversion, which is still regarded as a challenging topic in FWI. The ETKF-FWI multiparameter inversion yields improved models compared with conventional ones. More importantly, it makes it possible to assess the uncertainty associated with parameters cross-talks
El, Amri Mohamed. "Analyse d'incertitudes et de robustesse pour les modèles à entrées et sorties fonctionnelles." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAM015.
Повний текст джерелаThis thesis deals with the inversion problem under uncertainty of expensive-to-evaluate functions in the context of the tuning of the control unit of a vehicule depollution system.The effect of these uncertainties is taken into account through the expectation of the quantity of interest. The problem lies in the fact that the uncertainty is partly due to a functional variable only known through a given sample. We propose two approaches to solve the inversion problem, both methods are based on Gaussian Process modelling for expensive-to-evaluate functions and a dimension reduction of the functional variable by the Karhunen-Loève expansion.The first methodology consists in applying a Stepwise Uncertainty Reduction (SUR) method on the expectation of the quantity of interest. At each evaluation point in the control space, the expectation is estimated by a greedy functional quantification method that provides a discrete representation of the functional variable and an effective sequential estimate from the given sample.The second approach consists in applying the SUR method directly to the quantity of interest in the joint space. Devoted to inversion under functional uncertainties, a strategy for enriching the experimental design exploiting the properties of Gaussian processes is proposed.These two approaches are compared on toy analytical examples and are applied to an industrial application for an exhaust gas post-treatment system of a vehicle. The objective is to identify the set of control parameters that leads to meet the pollutant emission norms under uncertainties on the driving cycle
Kozlovskaya, E. (Elena). "Theory and application of joint interpretation of multimethod geophysical data." Doctoral thesis, University of Oulu, 2001. http://urn.fi/urn:isbn:9514259602.
Повний текст джерелаSanchez, Reyes Hugo Samuel. "Inversion cinématique progressive linéaire de la source sismique et ses perspectives dans la quantification des incertitudes associées." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAU026/document.
Повний текст джерелаThe earthquake characterization is a fundamental research field in seismology, which final goal is to provide accurate estimations of earthquake attributes. In this study field, various questions may rise such as the following ones: when and where did an earthquake happen? How large was it? What is its evolution in space and time? In addition, more challenging questions can be addressed such as the following ones: why did it occur? What is the next one in a given area? In order to progress in the first list of questions, a physical description, or model, of the event is necessary. The investigation of such model (or image) is the scientific topic I investigate during my PhD in the framework of kinematic source models. Understanding the seismic source as a propagating dislocation that occurs across a given geometry of an active fault, the kinematic source models are the physical representations of the time and space history of such rupture propagation. Such physical representation is said to be a kinematic approach because the inferred rupture histories are obtained without taking into account the forces that might cause the origin of the dislocation.In this PhD dissertation, I present a new hierarchical time kinematic source inversion method able to assimilate data traces through evolutive time windows. A linear time-domain formulation relates the slip-rate function and seismograms, preserving the positivity of this function and the causality when spanning the model space: taking benefit of the time-space sparsity of the rupture model evolution is as essential as considering the causality between rupture and each record delayed by the known propagator operator different for each station. This progressive approach, both on the data space and on the model space, does require mild assumptions on prior slip-rate functions or preconditioning strategies on the slip-rate local gradient estimations. These assumptions are based on simple physical expected rupture models. Successful applications of this method to a well-known benchmark (Source Inversion Validation Exercise 1) and to the recorded data of the 2016 Kumamoto mainshock (Mw=7.0) illustrate the advantages of this alternative approach of a linear kinematic source inversion.The underlying target of this new formulation will be the future uncertainty quantification of such model reconstruction. In order to achieve this goal, as well as to highlight key properties considered in this linear time-domain approach, I explore the Hamiltonian Monte Carlo (HMC) stochastic Bayesian framework, which appears to be one of the possible and very promising strategies that can be applied to this stabilized over-parametrized optimization of a linear forward problem to assess the uncertainties on kinematic source inversions. The HMC technique shows to be compatible with the linear time-domain strategy here presented. This technique, thanks to an efficient estimation of the local gradient of the misfit function, appears to be able to rapidly explore the high-dimensional space of probable solutions, while the linearity between unknowns and observables is preserved. In this work, I investigate the performance of the HMC strategy dealing with simple synthetic cases with almost perfect illumination, in order to provide a better understanding of all the concepts and required tunning to achieve a correct exploration of the model space. The results from this preliminary investigation are promising and open a new way of tackling the kinematic source reconstruction problem and the assessment of the associated uncertainties
Arubi, Isaac Marcus Tesi. "Multiphase flow measurement using gamma-based techniques." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/8347.
Повний текст джерелаSchmidt, Aurora C. "Scalable Sensor Network Field Reconstruction with Robust Basis Pursuit." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/240.
Повний текст джерелаLian, Jinghui. "Understanding how emissions and atmospheric transport control the variations of atmospheric CO2 in the Paris area : insights from laser-based measurements at city scale." Electronic Thesis or Diss., université Paris-Saclay, 2020. http://www.theses.fr/2020UPASV010.
Повний текст джерелаCities play an important role in tackling climate change as they account for more than 70% of global anthropogenic CO2 emissions. In recent years, several efforts have attempted to quantify city-scale CO2 emissions and establish a high spatially and temporally resolved inventory for supporting urban emission mitigation strategies. The so-called "top-down" inverse estimation of CO2 emissions constrained by independent atmospheric observations could serve to evaluate the consistency of traditional "bottom-up" inventories. A novel CO2 monitoring technique, known as the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITE™) trace gas measurement system, was deployed in central Paris for a 1-year monitoring of near-surface atmospheric CO2 concentrations along 30 horizontal chords. This system has a much wider spatial coverage than traditional in situ sampling and was expected to be more consistent with the spatial representativeness of the kilometer-scale resolution atmospheric transport models used for the city-scale atmospheric inversion.The primary objective of this thesis is to assess the potential contribution of this GreenLITE™ system, in addition to two urban and four peri-urban in situ CO2 measurement stations, for a better understanding of the spatiotemporal variations of CO2 concentrations within Paris and its vicinity. For this objective, I have developed a full modeling framework around the high-resolution Weather Research and Forecasting model (WRF) and its coupling with Chemistry (WRF-Chem), using CO2 emission inventories, estimates of the vegetation fluxes and boundary conditions provided by a large-scale simulation.Chapter 1 is a broad introduction to the subject while chapter 2-4 are built around three separate and publishable papers.Chapter 2 aims at evaluating whether the WRF model running at a 3-km horizontal resolution, with its various configurations, can reproduce the meteorological fields over the IdF region better than the 16-km resolution ECMWF global operational forecasts. The comparisons between WRF and ECMWF forecasts with respect to observations are carried out with a focus on three atmospheric variables (air temperature, wind and PBL height). The results of the sensitivity tests of different physics schemes and nudging options obtained in this chapter are used in subsequent research for the selection of appropriate WRF-Chem model setup in support of atmospheric CO2 transport modeling.Chapter 3 aims at understanding the spatiotemporal variations of CO2 concentrations within Paris and its vicinity during the 1-year GreenLITE™ operating period from September 2015 to December 2016. The analyses are based on CO2 data provided by GreenLITE™ together with six in situ stations and the 1 km-resolution WRF-Chem model coupled with two urban canopy schemes (Urban Canopy Model - UCM; Building Effect Parameterization - BEP). The GreenLITE™ data provide clear information that favors BEP over UCM in the description of vertical mixing and CO2 concentrations during the winter. However, there are indications of measurement noise in summer that limit the usefulness of the data. Furthermore, the model-observation mismatches clearly stress the difficulty of CO2 modeling within urban areas due to the large uncertainties both in the atmospheric transport and the emission inventory.Chapter 4 aims at investigating in detail the critical sources of errors that lead to the model-observation mismatches in the atmospheric CO2 modeling over Paris. These sources of misfit include uncertainties in the assumed distribution of anthropogenic emission, errors in the atmospheric transport, in biogenic CO2 fluxes and in CO2 boundary conditions at the edges of the atmospheric transport model domain. The lessons and insights from this chapter provide requirements and recommendations for the assimilation of CO2 measurements into the atmospheric inversion, when aiming at the quantification of CO2 emissions for the Paris region
Shin, Yoonghyun. "Neural Network Based Adaptive Control for Nonlinear Dynamic Regimes." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7577.
Повний текст джерелаNosjean, Nicolas. "Management et intégration des risques et incertitudes pour le calcul de volumes de roches et de fluides au sein d’un réservoir, zoom sur quelques techniques clés d’exploration Integrated Post-stack Acoustic Inversion Case Study to Enhance Geological Model Description of Upper Ordovicien Statics : from imaging to interpretation pitfalls and an efficient way to overcome them Improving Upper Ordovician reservoir characterization - an Algerian case study Tracking Fracture Corridors in Tight Gas Reservoirs : An Algerian Case Study Integrated sedimentological case study of glacial Ordovician reservoirs in the Illizi Basin, Algeria A Case Study of a New Time-Depth Conversion Workflow Designed for Optimizing Recovery Proper Systemic Knowledge of Reservoir Volume Uncertainties in Depth Conversion Integration of Fault Location Uncertainty in Time to Depth Conversion Emergence of edge scenarios in uncertainty studies for reservoir trap analysis Enhancing geological model with the use of Spectral Decomposition - A case study of a prolific stratigraphic play in North Viking Graben, Norway Fracture corridor identification through 3D multifocusing to improve well deliverability, an Algerian tight reservoir case study Geological Probability Of Success Assessment for Amplitude-Driven Prospects, A Nile Delta Case Study." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS085.
Повний текст джерелаIn the last 20 years, I have been conducting various research projects focused on the management of risks and uncertainties in the petroleum exploration domain. The various research projects detailed in this thesis are dealing with problematics located throughout the whole Exploration and Production chain, from seismic acquisition and processing, until the optimal exploration to development wells placement. Focus is made on geophysical risks and uncertainties, where these problematics are the most pronounced and paradoxically the less worked in the industry. We can subdivide my research projects into tree main axes, which are following the hydrocarbon exploration process, namely: seismic processing, seismic interpretation thanks to the integration with various well informations, and eventually the analysis and extraction of key uncertainties, which will be the basis for the optimal calculation of in place and recoverable volumes, in addition to the associated risk analysis on a given target structure. The various research projects that are detailed in this thesis have been applied successfully on operational North Africa and North Sea projects. After introducing risks and uncertainty notions, we will detail the exploration process and the key links with these issues. I will then present four major research projects with their theoretical aspects and applied case study on an Algerian asset
Morales, Barrera Stephanie Lucero, and Huillca Saori Kiara Kanashiro. "Evaluacion de proyectos mediante opciones reales." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/653322.
Повний текст джерелаThis article presents the great importance of the use of the real options valuation method in investment projects with a high degree of uncertainty, and why it is a better option unlike the traditional methods currently known, which are difficult to adapt to. situations where there is a high index of uncertainty. This article gives an overview of real options from a literary review and the emergence of them based on financial options, the types of real options that exist and the different methodologies required to find their value. Finally, six studies carried out by different authors are shown, showing that this methodology is the most appropriate for evaluating projects, since it takes into account the flexibility required in projects that are in highly volatile markets such as the construction sector, mining, biotechnology, among others.
Trabajo de Suficiencia Profesional
Schnaidt, Sebastian. "Improving uncertainty estimation in geophysical inversion modelling." Thesis, 2015. http://hdl.handle.net/2440/111402.
Повний текст джерелаThesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Physical Sciences, 2015.
Benavente, Bravo Roberto Fabian. "Rapid Finite Fault Inversion for Megathrust Earthquakes." Phd thesis, 2016. http://hdl.handle.net/1885/108615.
Повний текст джерелаStripling, Hayes Franklin. "The Method of Manufactured Universes for Testing Uncertainty Quantification Methods." 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8986.
Повний текст джерелаRazafindrakoto, Hoby. "New Insights on the Uncertainties in Finite-Fault Earthquake Source Inversion." Diss., 2015. http://hdl.handle.net/10754/554294.
Повний текст джерелаSimpson, Janelle Maree. "Understanding interpretation limitations due to MT inversion variability: examples from the Mount Isa Province, Queensland, Australia." Thesis, 2019. http://hdl.handle.net/2440/122614.
Повний текст джерелаThesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2019
Griffiths, Shawn Curtis. "Issues related to site property variability and shear strength in site response analysis." Thesis, 2015. http://hdl.handle.net/2152/31370.
Повний текст джерелаChevalier, Clément. "Fast uncertainty reduction strategies relying on Gaussian process models." Phd thesis, 2013. http://tel.archives-ouvertes.fr/tel-00879082.
Повний текст джерелаMartin, James Robert Ph D. "A computational framework for the solution of infinite-dimensional Bayesian statistical inverse problems with application to global seismic inversion." Thesis, 2015. http://hdl.handle.net/2152/31374.
Повний текст джерела