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 40 for “"Spatial Filtering"”.
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Spatial Filtering for Small Objects
No abstract prepared.
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Scaling finite difference methods in large eddy simulation of jet engine noise to the petascale: numerical methods and their efficient and automated implementation
… rely on the implicitly formulated compact spatial partial differentiation and spatial filtering schemes, a crucial component of which is an embedded solver for tridiagonal linear systems spatially oriented along the three coordinate directions of the computational space. Traditionally, …
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Methodological advancements for improving performance and generating ensemble ecological niche models
<p>This study employs spatial filtering of occurrence data with the aim of reducing overfitting to sampling bias in ecological niche models (ENMs). Sampling bias in geographic space leads to localities that may also be biased in environmental space. If so, the model can overfit to those biases. As …
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A New Look at the Theory of Double-Aperture Speckle Photography
… derive the final fringe formation equations in a spatial filtering setup for a double-apertures specklegram. Both the pointwise and full-field filtering setups are analyzed. The resulting equations are shown to be more complete and exact than the equations from the conventional Moire analysis.
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High-Speed Data Acquisition and FPGA Detected Pulse Blanking System for Interference Mitigation in Radio Astronomy
… (RFI). One strategy to remove RFI is to apply spatial filtering using an array antenna. This thesis documents the development of a high-speed data acquisition system used to record data from 7- and 19-element phased array feeds. The system supports synchronous sampling over all channels and …
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Comparison and Development of Algorithms for Motor Imagery Classification in EEG- based Brain-Computer Interfaces
… tested included the popular method of common spatial patterns (CSP) spatial filtering followed by linear discriminant analysis (LDA) classification of log-variance features (CSP+LDA). A second set of algorithms used classification based on concepts from Riemannian geometry. The basic idea of …
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A Prototype Platform for Array Feed Development
… astronomers. One potential solution utilizes spatial filtering by placing an array of electrically small antennas at the focal plane of a parabolic reflector. This thesis documents the design and characterization of a prototype array feed and RF receiver that were used to demonstrate the …
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Domain-Independent Mode Estimation for Human-Robot Collaboration
… states while integrating recursive Bayesian filtering to maintain belief under noisy observations. Unlike low-level trajectory tracking or deep-learned classifiers, qualitative spatial filtering operates at the right level of abstraction to recognize symbolic actions. It can also generalize …
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Instrumentation of partical conveying using electrical charge tomography.
… of circular and rectangular electrodes. The spatial filtering effect of these sensors is investigated. Cross correlation is briefly reviewed and a software program is presented and tested. For tomographic imaging the forward problem for the individual sensors is modelled, used to solve the …
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Active damping of a structure with low-frequency and closely- spaced modes: experiments and theory
… design of a structure and control system. A spatial filtering method for determining the modal response of the structure from the physical response is also investigated.
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Adaptive Antenna Arrays Applied to Position Location
… can be used for interference rejection through spatial filtering, position location through direction finding measurements, and developing improved channel models through angle of arrival channel sounding measurements. This thesis provides an overview of the technical challenges involved in …
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An Economic Analysis of Evolving Health Hazards
… on these health hazards. Chapter 2 develops a spatial filtering panel data count model to examine the factors that contributed to the high prevalence of human West Nile virus (WNV) in California and Colorado using county-level data from 2003 to 2007. An econometric analysis was performed using …
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Segmentation of textured images
… Mapping Approach (LSM) and the Multichannel Spatial Filtering Approach (MSF). In the LFS approach, a multiresolution scheme for extracting texture features is introduced. This scheme produces features which can describe texture characteristics at different resolution levels. The gradient …
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Commutation Error in Reduced Order Modeling
We investigate the effect of spatial filtering on the recently proposed data-driven correction reduced order model (DDC-ROM). We compare two filters: the ROM projection, which was originally used to develop the DDC-ROM, and the ROM differential filter, which uses a Helmholtz operator to attenuate …
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Evaluation of spatial-spectral filtering in non-paraxial volume holographic imaging systems
… of transmission-mode volume phase holograms as spatial-spectral filters in optical systems for microscopic medical imaging are evaluated. In experiment, the relationship between the angle of incidence and diffraction efficiency are invesitgated for wavelength-detuned multiplex holograms to …
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Time keeping in myriad networks : theories, solutions and applications
… in our clock model and propose a novel Kalman filtering technique for de-noising (remove of network jitter) during the NTP time synchronization process. The parameters of the Kalman linear estimator are optimal and they are computed online from the network environment, with a well-defined …
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Large Eddy Simulation Reduced Order Models
This dissertation uses spatial filtering to develop a large eddy simulation reduced order model (LES-ROM) framework for fluid flows. Proper orthogonal decomposition is utilized to extract the dominant spatial structures of the system. Within the general LES-ROM framework, two approaches are …
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Optical-parametric-amplification applications to complex images
… Fourier-plane OPA imaging of more than a single spatial-frequency component of an image. We observe more than 30 distinct spatial frequency components in both our amplified image and our wavelength shifted image. We have demonstrated all-optical spatial filtering for these complex images. We have …
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