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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
The Computation Of Fluid Velocity In A Closed Cavity With A Moving Lid, Daniel A. Montez
The Computation Of Fluid Velocity In A Closed Cavity With A Moving Lid, Daniel A. Montez
Theses and Dissertations - UTB/UTPA
We consider a cavity filled with fluid whose three sides are stationary and the lid at the top is moving at a constant speed. The flow in the cavity is modeled using the conservation of mass and momentum equations with proper boundary conditions. We compute the fluid velocity for the steady state case using the finite element method. We seek the weak formulation and develop a finite element model based on the Galerkin method. Furthermore we use the penalty function method to modify our weak formulation to eliminate the pressure. The Gaussian quadrature method is used to evaluate our integrals …
Methods For Increasing Domains Of Convergence In Iterative Linear System Solvers, David Michael Imberti
Methods For Increasing Domains Of Convergence In Iterative Linear System Solvers, David Michael Imberti
Open Access Dissertations
In this thesis, we introduce and improve various methods for increasing the domains of convergence for iterative linear system solvers. We rely on the following three approaches: making the iteration adaptive, or nesting an inner iteration inside of a previously determined outer iteration; using deflation and projections to manipulate the spectra inherent to the iteration; and/or focusing on reordering schemes. We will analyze a specific combination of these three strategies. In particular, we propose to examine the influence of nesting a Flexible Generalized Minimum Residual algorithm together with an inner Recursive Projection Method using a banded preconditioner resulting from the …
Modeling And Control Of Nanoparticle Bloodstream Concentration For Cancer Therapies, Scarlett S. Bracey
Modeling And Control Of Nanoparticle Bloodstream Concentration For Cancer Therapies, Scarlett S. Bracey
Doctoral Dissertations
Currently, the most commonly used treatments for cancerous tumors (chemotherapy, radiation, etc.) have almost no method of monitoring the administration of the treatment for adverse effects in real time. Without any real time feedback or control, treatment becomes a "guess and check" method with no way of predicting the effects of the drugs based on the actual bioavailability to the patient's body. One particular drug may be effective for one patient, yet provide no benefit to another. Doctors and scientists do not routinely attempt to quantifiably explain this discrepancy. In this work, mathematical modeling and analysis techniques are joined together …
Examine Participant Dropout, Undiagnosed Diabetes And Undiagnosed Prediabetes In A Chronic Disease Prevention Education Program, Yiwen Cao
Theses and Dissertations - UTB/UTPA
There were 2768 participants enrolled in a chronic disease prevention education program. Survey and health measurements were obtained at three time points. We examine potential factors that might contribute to participant dropout, undiagnosed diabetes and undiagnosed prediabetes respectively. Logistic regression was used to examine the association between participant dropout and predictors, and to compare the odds of being undiagnosed with diabetes and prediabetes. We found that the potential predictors for participant dropout included age, employment, insurance, diabetes, self-reported health status, session type, program duration and curriculum. Factors affecting undiagnosed diabetes and prediabetes were age, self-reported health status birth country, limited …
Synthetic Aperture Radar With Compressed Sensing, Yufeng Cao
Synthetic Aperture Radar With Compressed Sensing, Yufeng Cao
Theses and Dissertations - UTB/UTPA
A general synthetic aperture radar (SAR) signal model is derived from the Maxwell’s equations, and compressed sensing are introduced to the signal model for SAR image reconstruction. Random Partial Fourier Matrices were applied to prove that compressed sensing can be used to this signal model from the viewpoint of mathematics. In the numerical simulation part, we show that the procedure of basis pursuit can reconstruct SAR image, based on our main results, which is shown efficient in comparison with the matched filter algorithm.
On Cubic Multisections, Andrew Alaniz
On Cubic Multisections, Andrew Alaniz
Theses and Dissertations - UTB/UTPA
In this thesis, a systematic procedure is given for generating cubic multi-sections of Eisenstein series. The relevant series are determined from Fourier expansions for Eisenstein series by restricting the congruence class of the summation index modulo three. The resulting series are shown to be rational functions of the Dedekind eta function. A more general treatment of cubic dissection formulas is given by describing the dissection operators in terms of linear transformations.
Lax Pairs For Some Nonlinear Equations, Ana Castillo
Lax Pairs For Some Nonlinear Equations, Ana Castillo
Theses and Dissertations - UTB/UTPA
Several methods have been proposed to approach the topic of integrable systems of nonlinear partial differential equations. One of these methods is called the Lax pair. The Lax pair is a pair of matrices or operators, that depend on time and satisfy the Lax equation. Based on the inverse scattering method introduced by Gardner, Greene, Kruskal and Miura (1967), Peter Lax introduced the Lax pair to derive soliton equations from the Lax equation. This thesis provides with a brief background on soliton theory, inverse scattering theory, and Lax pairs. The details missing in the work published by Ablowitz, Kaup, Newell, …
Traveling Wave Solution To Two-Dimensional Burgers-Korteweg-De Vries Equation, Xiaoqian Gong
Traveling Wave Solution To Two-Dimensional Burgers-Korteweg-De Vries Equation, Xiaoqian Gong
Theses and Dissertations - UTB/UTPA
In this thesis, we study the Two-Dimensional Burgers-Korteweg-de Vries (2D-BKdV) equation by analyzing the equivalent Abel equation, which indicates that under some particular conditions, the 2D-BKdV equation has a unique bounded traveling wave solution. By using the theorem of contractive mapping, a traveling wave solution to the 2D-BKdV equation is expressed explicitly. In the end, the behavior of the proper solution of the 2D-BKdV equation is established by applying the comparison theorem of differential equations.
A Mathematical Model And Numerical Method For Thermoelectric Dna Sequencing, Liwei Shi
A Mathematical Model And Numerical Method For Thermoelectric Dna Sequencing, Liwei Shi
Doctoral Dissertations
DNA sequencing is the process of determining the precise order of nucleotide bases, adenine, guanine, cytosine, and thymine within a DNA molecule. It includes any method or technology that is used to determine the order of the four bases in a strand of DNA. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery. Thermoelectric DNA sequencing is a novel method to sequence DNA by measuring the heat that is released when DNA polymerase inserts a deoxyribonucleoside triphosphate into a growing DNA strand. The thermoelectric device for this project is composed of four parts: …
Mathematical Modeling Of Two-Phase Arterial Blood Flow, Ani Emire Garcia Escorcia
Mathematical Modeling Of Two-Phase Arterial Blood Flow, Ani Emire Garcia Escorcia
Theses and Dissertations - UTB/UTPA
Problem of blood flow in an artery with or without catheter and in the presence of single or multi stenosis will be considered. The presence of stenosis locally thickens the artery wall and the use of catheter in the affected area is very important to the diagnostic and treatment of the patient. The blood flow in the arterial tube is represented by a two-phase model composing a suspension of erythrocytes in plasma. The governing equations for both fluid and particles are solved subjected to reasonable modeling and approximations. The important quantities such as blood speed, blood pressure force, impedance (blood …
Compressed Sensing For Multiple Input-Multiple Output Radar Imaging, Juan F. Lopez Jr.
Compressed Sensing For Multiple Input-Multiple Output Radar Imaging, Juan F. Lopez Jr.
Theses and Dissertations - UTB/UTPA
Multiple input - multiple output (MIMO) radar utilizes the transmission of spatially diverse waveforms from a static antenna array to gather information about the desired scene. We will demonstrate how techniques from compressed sensing can be applied to image formation in MIMO radar when in the presence of undersampling. We analyze the problem under the general theoretical framework of inverse scattering.
A Model For The Micro-Doppler Effect Of The Quadrupedal Body Motion, Noe Pena
A Model For The Micro-Doppler Effect Of The Quadrupedal Body Motion, Noe Pena
Theses and Dissertations - UTB/UTPA
In radar returns from quadrupedal body motion the micro-Doppler effect is present. This effect can be used to identify and distinguish this motion from others. In this work the model for the micro-Doppler effect due to quadrupedal motion is developed from Maxwell’s equations. The common gait for all quadrupedal mammal motion is described and analyzed. The radar crossection of quadrupedal motion backscattering is discussed. Quadrupedal motion is simulated and the radar returns are analyzed. The micro-Doppler signatures are decomposed and kinematic parameters are extracted