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 20 of 21 for “"model mismatch"”.
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Model mismatch paradigm for probe based nanoscale imaging.
… The central tenet of the thesis is to model, the known information about the system and then focus on perturbations of these known dynamics or model, to sense the effects due to changes in the environment such as changes in material properties or surface topography. Thus a model …
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Parameter estimation in reconstructing temperature fields during hyperthermia.
… problem are investigated from simple direct models. The general conditions under which these multiple minima occur are shown to be solely due to the existence of symmetries in the inverse problem formulation. Both an adjoint formulation and a sensitivity equation method are derived and used …
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Multiscale modeling and model predictive control of processing systems
Traditional approaches in Model Predictive Control (MPC) suffer from several weaknesses such as: (a) Satisfying the output constraints over a finite control horizon and guaranteeing closed loop stability. (b) The need for infinite horizon for robust stability and performance. (c) Limited …
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Performance and Robustness Assessment for a Robust Port-Hamiltonian Flight Controller
… To replicate flight, measurement noise, model mismatch, wind, and discretization with time delay were implemented in a collection of simulation studies to understand which disturbances the novel control law was most sensitive to. Due to the non-additive nature and magnitude of the applied …
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Learning from Geometry
<p>Subspaces and manifolds are two powerful models for high dimensional signals. Subspaces model linear correlation and are a good fit to signals generated by physical systems, such as frontal images of human faces and multiple sources impinging at an antenna array. Manifolds model sources that are …
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Rollover prevention and path following of a scaled autonomous vehicle using nonlinear model predictive control
… Scaled Ground Vehicle (ASGV) using Nonlinear Model Predictive Control (NMPC). Open Source Software (OSS) known as Automatic Control and Dynamic Optimisation (ACADO) is used to design and simulate the NMPC controller based on an eight Degree of Freedom (8 DOF) nonlinear vehicle model with …
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Robust Machine Learning Methods in Solving Inverse Problems
… to lack interpretability and physical grounding. Model-based architectures such as loop unrolling (LU) draw inspiration from optimization by unrolling the iterative updates for an optimization-based solver and then learning a regularizer from data. These architectures are the current …
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Proportional navigation target tracking
… in their guidance systems, it is best to model their motion using the proportional navigation guidance law. An unbiased narrowband filter is required because the state estimate is used to extrapolate the trajectory over the long time of flight of the gun projectile used to intercept the …
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Exploring scatterer anisotrophy in synthetic aperture radar via sub-aperture analysis
… frequency dependencies which are not always well modeled by standard SAR imaging techniques based on the ideal point scattering model. This is particularly the case for highresolution wide-band and wide-aperture data where model deviations are even more pronounced. If ignored, these deviations …
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Multi-configuration model tuning for precision opto-mechanical systems
… future space-based observatories that simulation models physically represent the designed system and are able to track along configuration changes. This thesis outlines a three-step procedure for model tuning of complex opto-mechanical systems in the presence of measured experimental data. It is …
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Optimal control of fed-batch fermentation processes
… give similar performance in a case of perfect model while the closed loop optimal control provides better performance than the open loop method in a case of plant/model mismatch. The better performance of the closed loop optimal control is due to an ability to compensate for the modelling …
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Pore pressure, and the interdependency between lithology, porosity, and acoustic log response targeting the Vaca Muerta Formation
… set of equations. In an effort to further reduce model mismatch, Bowers' original equations are modified to include porosity and lithology effects on velocity. To do so, logs from well within the LJE block in the Neuquén Basin are depth shifted to a reference well. Depth shifting shows a …
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Parameter Estimation Techniques for Nonlinear Dynamic Models with Limited Data, Process Disturbances and Modeling Errors
… from limited available data, assuming that the model structure is correct, while the second problem involves estimating unmeasured disturbances, assuming that enough data are available for parameter estimation. In the first part of this thesis, a model is developed to predict rates of …
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Permeability Distribution Estimation Based on Semi-Analytical Reservoir Simulator
… function which usually includes the sum of data mismatch part as well as the sum of prior model mismatch part. For our semi-analytical simulator, the choice of optimization algorithms to minimize the objective function becomes of vital importance. For our simulator, we considered both gradient …
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Steady-State Bumpless Transfer Under Controller Uncertainty: Methodology and Applications
… uncertainty. The latter is defined to be the mismatch between the controller model and the actual implemented controller. To address this problem, a novel state/output feedback bumpless transfer topology is proposed that employs the nominal state of the offiine controller and, through the use …
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Formal analysis of state estimation for nonlinear model predictive control
… when implemented in the formulation of nonlinear model predictive control. The analysis is facilitated by two nonlinear optimal state estimation methods: augmented state EKF (ASEKF) and augmented state UKF (ASUKF) for comparison purposes. Each state estimation method is coupled to the same NMPC …
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User modelling for evaluation of direct manipulation interfaces
This thesis applies models of user action to usability evaluation of direct manipulation interfaces. In particular, the utility of a Model of Action for assisting novice evaluators in usability tests is investigated. An initial model of user action is proposed, based on the theory of action …
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A framework for enabling the utilization of flexible loads to provide frequency regulation
… which groups DERs into simple, yet accurate, models; offers capability based on these models; and coordinates the DERs to provide the service. Flexible loads have been proposed as a low-cost provider of frequency regulation. For example, the flexibility of loads with inherent thermal energy …
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Multiarray Passive Acoustic Localization and Tracking
… obtained confirm the practicality of theoretical models, support numerical results, and illustrate the effectiveness of the proposed strategies and the system as a whole. In many situations of interest, obstacles to wave propagation such as terrain or buildings exist that provide unique challenges …
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Distortion-optimal parallel MRI with sparse sampling: from adaptive spatio-temporal acquisition to self-calibrating reconstruction
… acquisition and reconstruction in model-based pMRI wherein the signal model is a sparse support. We develop a highly-accelerated real-time dynamic MRI technique, dubbed PARADISE, which incorporates a physiologically-driven sparse support model in the joint spatial domain and …
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