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 14 of 14 for “"Stochastic Estimation"”.
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Stochastic estimation of near-wall closure in turbulence models
Linear stochastic estimation (LSE), a best mean square estimator, is used to formulate boundary closure models for the numerical large eddy simulation (LES) of turbulence. The stochastic estimation method resolves coherent structure of the wall layer using empirical correlation functions, and …
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Collaborative concurrent mapping and localization
… vehicles. The algorithm presented is based on stochastic estimation and uses a feature-based approach to extract landmarks from the environment. The theoretical framework for the collaborative CML algorithm is presented, and a convergence theorem central to the cooperative CML problem is proved …
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APPLICATION OF DATA FUSION TO FLUID DYNAMIC DATA
… as proper orthogonal decomposition (POD), linear stochastic estimation (LSE), and wavelet analysis. This process can generate large quantities of data and a method of handling all of the data and the techniques in an efficient manner is required. To accomplish this, a framework was developed that …
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Simultaneous stochastic mapping and localization
… mapping and localization problem is cast as a stochastic estimation problem. Based on Kalman filtering techniques, augmented stochastic mapping is introduced as a method for performing concurrent mapping and localization in realistic scenario simulations and experiments. The role of data …
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Empirical mode decomposition applied to planar and volumetric velocity field measurements of a supersonic separated flow
… the shear layer and the trailing wake. Linear stochastic estimation of these three-dimensional results revealed the presence of conventional hairpin and counter-hairpin vortices within the shear layer.
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Dynamic Estimation of Large-Scale Flow Events in Open Cavity Flows
… of two data-driven techniques, Linear Stochastic Estimation (LSE) and Dynamic Mode Decomposition (DMD), in an innovative approach called sensor-based conditional DMD (conDMD). The sensor-based conDMD approach applies DMD directly to pressure measurements, contrary to traditional DMD …
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Generating pictures from waves : aspects of image formation
… researchers analyze coherent sound waves using stochastic estimation theory and diffraction formulas from physics. The ability to inexpensively fabricate analog circuitry and digital logic for millimeter-wave radar and ultrasound creates opportunities in comparing diverse perspectives on image …
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Characterization of Subsurface Heterogeneity Using Transient Hydraulic and Tracer Tomography
… reduce the computational cost, we developed an estimation approach that utilizes the zeroth and first temporal moments of well hydrographs, instead of drawdown itself. The governing equations and adjoint equations for the temporal moments are Poisson's equations. These equations demand less …
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Uncertainty and sensitivity analysis methods for improving design robustness and reliability
… systems. The design process is viewed as a stochastic estimation problem in which the level of uncertainty in the design parameters and quantities of interest is characterized probabilistically, and updated through successive iterations as new information becomes available. Proposed …
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Complex Equilibrium of Laterally Curved Wakes
… in the turbulent structure of both wakes. Linear stochastic estimation reveals the presence of spanwise and double-roller eddy structures in the plane wake and only spanwise eddies were detected for the ring wake.
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Contributions to the Understanding of Turbulent Boundary Layers Over Curved Walls
… relied on two-point statistical methods. Linear stochastic estimation showed that hairpin vortex packets had a significant role, irrespective of the pressure gradient and wall curvature. Consequently, the correlation contours based on the wall-tangent velocity were forward leaning. The near-wall …
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Three-dimensional turbulence mechanisms in a supersonic separated/reattaching longitudinal cylinder wake
… turbulence analysis techniques, such as linear stochastic estimation (LSE), proper orthogonal decomposition (POD), and several others. The volumetric TPIV data allowed for the identification and characterization of 3-D coherent turbulent structures within this flow, including upright hairpin …
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Unsteady Turbulence Interaction in a Tip Leakage Flow Downstream of a Simulated Axial Compressor Rotor
… Two point correlation measurements and linear stochastic estimation are used to reveal the structure of this aperiodic part for a tip gap of 3.3% chord. The aperiodic fluctuation, containing most of the turbulence energy, is found appearing to be organized structures in large scale, and making …
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Modern Methods in Machine Learning as Applied to the Study of a Complex Supersonic Jet Flow
… fundamental experiments, data fusion, and novel estimation techniques based on modern machine learning techniques.</p> <p>The experiments described herein focus on a Multi-Aperture Rectangular Single Expansion Ramp Nozzle (MARS ) and are a direct extension of the research performed by Magstadt …