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Theses/Dissertations

Computer algorithms

University of Tennessee at Chattanooga

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Tetrahedral Mesh Optimization And Generation Via Topological Transformations And Gradient Based Node Perturbation, Christopher B. Hilbert Aug 2015

Tetrahedral Mesh Optimization And Generation Via Topological Transformations And Gradient Based Node Perturbation, Christopher B. Hilbert

Masters Theses and Doctoral Dissertations

A general tetrahedral mesh optimization scheme utilizing both topological changes (i.e. flips) and gradient-based vertex optimization (i.e. smoothing) is demonstrated. This scheme is used in the optimization of tetrahedral meshes created by third-party software as well as a grid generation methodology created for this work. The particular algorithms involved are explained in detail including, an explication of the primary optimization metric, weighted condition number. In addition, a thorough literature review regarding tetrahedral mesh generation is given.


Compressive Sensing Based Imaging Via Belief Propagation, Preethi Modur Ramachandra May 2012

Compressive Sensing Based Imaging Via Belief Propagation, Preethi Modur Ramachandra

Masters Theses and Doctoral Dissertations

Multiple description coding (MDC) using Compressive Sensing (CS) mainly aims at restoring an image from a small subset of samples with reasonable accuracy using an iterative message passing decoding algorithm commonly known as Belief Propagation (BP). The CS technique can accurately recover any compressible or sparse signal from a lesser number of non-adaptive, randomized linear projection samples than that specified by the Nyquist rate. In this work, we demonstrate how CS-based encoding generates measurements from the sparse image signal and the measurement matrix. Then we demonstrate how a BP decoding algorithm reconstructs the image from the measurements generated. In our ...


Fully Anisotropic Split-Tree Adaptive Refinement Mesh Generation Using Tetrahedral Mesh Stitching, Vincent Charles Betro Aug 2010

Fully Anisotropic Split-Tree Adaptive Refinement Mesh Generation Using Tetrahedral Mesh Stitching, Vincent Charles Betro

Masters Theses and Doctoral Dissertations

Due to the myriad of geometric topologies that modern computational fluid dynamicists desire to mesh and run solutions on, the need for a robust Cartesian Mesh Generation algorithm is paramount. Not only do Cartesian meshes require less elements and often help resolve flow features but they also allow the grid generator to have a great deal of control in so far as element aspect ratio, size, and gradation. Fully Anisotropic Split-Tree Adaptive Refinement (FASTAR) is a code that allows the user to exert a great deal of control and ultimately generate a valid, geometry conforming mesh. Due to the split-tree ...