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 17 of 17 for “"Sparse sampling"”.
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Constrained imaging: denoising and sparse sampling
Made available in DSpace on 2011-05-25T14:59:20Z (GMT). No. of bitstreams: 2 Haldar_Justin.pdf: 25586752 bytes, checksum: 13b473014d3b4c607a03de95d1f71669 (MD5) license.txt: 4061 bytes, checksum: 1d9342c42cf91c0d9be87c7868170d96 (MD5)
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Fast MRI with sparse sampling: models, algorithms, and applications
… (MRI) methods are based on the Shannon-Nyquist sampling theorem. The number of required Nyquist samples grows exponentially with respect to the underlying physical dimension of the imaging problem, resulting in significant difficulty of achieving high resolution for higher-dimensional imaging …
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Distortion-optimal parallel MRI with sparse sampling: from adaptive spatio-temporal acquisition to self-calibrating reconstruction
… inverse problems associated with multi-channel sampling and reconstruction that pertain to parallel magnetic resonance imaging (pMRI). The first part of this dissertation addresses adaptive design of spatio-temporal acquisition and reconstruction in model-based pMRI wherein the signal model is a …
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A Technique for Evaluating the Uncertainties in Path Loss Predictions Caused by Sparsely Sampled Terrain Data
… the terrain, and generally the databases are sparsely sampled relative to the electromagnetic wavelengths used for communication systems. This work primarily develops a technique to evaluate the effects of that sparsity on the uncertainty of propagation models. That is accomplished by …
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Image guidance in cardiac electrophysiology
… mapping procedure results in relatively sparse sampling of the heart and a significant amount of time and skill are require to generate these maps. In this thesis, we present our software system for the integration of pre-operative, patient-specific magnetic resonance (MR) or computed …
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Advanced Statistical Modeling for Model-Based Iterative Reconstruction for Single-Energy and Dual-Energy X-Ray CT
… imaging conditions, such as low-dose and sparse-sampling scans, each requiring refined statistical models including the data model and the prior model. In this dissertation, we developed an MBIR algorithm for dual-energy CT that included a joint data-likelihood model to account for …
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Bacterial and archaeal community structure across a gradient of saline lakes in Kiritimati, Republic of Kiribati
… gradients remains limited, given the sparse sampling of these systems worldwide. Here we investigate a series of distinct microbial communities across a gradient of natural saline lakes on Kiritimati to define how mat communities in hypersaline lakes, where microbial mats have been …
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Wide-field magnetic field imaging with nitrogen vacancy centers in nanodiamonds at high frame-rates
… be treated as absolute magnetometers. Further, a sparse sampling protocol is implemented that enables time resolved magnetometry and is used to image the magnetic field of a current carrying wire at greater than 33 Hz speeds with magnetic field sensitivities better than ... over a 10 [mu]m x 10 …
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American rivers are transporting more sediment in less time
… of sediment dynamics have been hindered by sparse sampling that misses the short-lived events responsible for most annual transport. This study develops a deep learning framework that combines high-frequency turbidity sensors and long-term hydrometeorological datasets to reconstruct daily …
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Mathematical modeling and sparse identification of delay-driven dynamical systems with applications to gene regulatory networks
… framework is developed by extending the Sparse Identification of Nonlinear Dynamics (SINDy) methodology to systems with distributed delay using the Linear Chain Trick. This approach enables the simultaneous identification of governing equations, effective delay, and delay distribution …
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Measuring tropical forest disturbance and regrowth with spaceborne lidar
… to measure change, because of the instrument’s sparse sampling pattern, geolocation uncertainty, and unwieldy data size – billions of measurements comprising hundreds of terabytes of raw data. Indeed, early publications raised explicit doubts that GEDI would be suitable for studying forest …
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Optimizing pharmacokinetic studies utilizing microsampling
… The first two are motivated by the new blood sampling method of microsampling, which requires a smaller sample volume than traditionally used. Firstly, a methodology is introduced for comparing microsampling to traditional sampling using the derived PK parameters from PK modelling, to find …
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The Vela Supercluster - does it provide the missing link to explain the local flow fields?
… corresponding virial masses. Although the VSC is sparsely sampled, we find 13 galaxy clusters and 22 galaxy groups contained within it. The richness and the masses of these galaxy clusters/groups are comparable with the galaxy clusters/groups found within the Shapley Supercluster by Proust et al. …
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A subspace approach to high-resolution magnetic resonance spectroscopic imaging
… subspace, which enables the design of special sparse sampling strategies for accelerated spatiospectral encoding and special image reconstruction strategies for determining the subspace and reconstructing the underlying spatiospectral function of interest from the sparse data. Using the SPICE …
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A data-driven approach to quasi-static ultrasonic elasticity imaging
… to QUSE. We first demonstrate that a very sparse sampling of force-displacement data is sufficient for estimating the linear-elastic properties of gelatin phantoms when the interior geometry is known. Then, we introduce Cartesian NNCMs (CaNNCMs), a novel ANN architecture, capable of …
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Simultaneous fMRI and metabolic imaging of the brain using spice
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-12-01
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Cortical Responses to Illusory and Surface Color
… It is currentlyappreciated that a relatively sparse sampling of visual information from the world results in arich visual percept, supporting the idea that much of our vision is actually reconstructed frompast experience. Another goal of the present study is to apply electrophysiological …