Mathematics Commons^™

Structured Matrices And The Algebra Of Displacement Operators, Ryan Takahashi

HMC Senior Theses

Matrix calculations underlie countless problems in science, mathematics, and engineering. When the involved matrices are highly structured, displacement operators can be used to accelerate fundamental operations such as matrix-vector multiplication. In this thesis, we provide an introduction to the theory of displacement operators and study the interplay between displacement and natural matrix constructions involving direct sums, Kronecker products, and blocking. We also investigate the algebraic behavior of displacement operators, developing results about invertibility and kernels.

Mathematical Knowledge For Teaching And Visualizing Differential Geometry, Nathan Pinsky

HMC Senior Theses

In recent decades, education researchers have recognized the need for teachers to have a nuanced content knowledge in addition to pedagogical knowledge, but very little research was conducted into what this knowledge would entail. Beginning in 2008, math education researchers began to develop a theoretical framework for the mathematical knowledge needed for teaching, but their work focused primarily on elementary schools. I will present an analysis of the mathematical knowledge needed for teaching about the regular curves and surfaces, two important concepts in differential geometry which generalize to the advanced notion of a manifold, both in a college classroom and …

Topological Complexity Of H-Spaces, Gregory Lupton, Jerome Scherer

Mathematics and Statistics Faculty Publications

Let X be a (not-necessarily homotopy-associative) H-space. We show that TCn+1(X) = cat (Xn), forn≥1, where TCn+1(−) denotes the so-called higher topological complexity introduced by Rudyak, and cat (−) denotes the Lusternik-Schnirelmann category. We also generalize this equality to an inequality, which gives an upper bound for TCn+1(X), in the setting of a space Y acting on X.

Superstable Manifolds Of Invariant Circles, Scott R. Kaschner

Scholarship and Professional Work - LAS

Let f : X → X be a dominant meromorphic self-map, where X is a compact, connected complex manifold of dimension n > 1. Suppose there is an embedded copy of P1 that is invariant under f, with f holomorphic and transversally superattracting with degree a in some neighborhood. Suppose also that f restricted to this line is given by z → z^b, with resulting invariant circle S. We prove that if a ≥ b, then the local stable manifold W^s_loc(S) is real analytic. In fact, we state and prove a suitable localized version that can …

Tournament Directed Graphs, Sarah Camille Mousley

Undergraduate Honors Capstone Projects

Paired comparison is the process of comparing objects two at a time. A tournament in Graph Theory is a representation of such paired comparison data. Formally, an n-tournament is an oriented complete graph on n vertices; that is, it is the representation of a paired comparison, where the winner of the comparison between objects x and y (x and y are called vertices) is depicted with an arrow or arc from the winner to the other.

In this thesis, we shall prove several results on tournaments. In Chapter 2, we will prove that the maximum number of vertices …

Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Charged particle chaos and its collective effects in different magnetic geometries are investigated in a sequence of various numerical experiments. The fields generated by the particles as a result of interaction with the background electric and magnetic fields is not accounted for in the simulation. An X-line is first used to describe the geometry of the magnetotail prior to magnetic reconnection and a study of the behavior of charged particles is done from a microscopic viewpoint. Another important geometry in the magnetotail prior to substorm onset is Bifurcated Current Sheet. The same analysis is done for this configuration. The existence …

Section Abstracts: Astronomy, Mathematics And Physics

Virginia Journal of Science

Abstracts of the Astronomy, Mathematics and Physics Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Level Crossing Times In Mathematical Finance, Ofosuhene Osei

Electronic Theses and Dissertations

Level crossing times and their applications in finance are of importance, given certain threshold levels that represent the "desirable" or "sell" values of a stock. In this thesis, we make use of Wald's lemmas and various deep results from renewal theory, in the context of finance, in modelling the growth of a portfolio of stocks. Several models are employed .

Asian Carp Could Help Us Solve Hunger Problem, Michael (Dung) Tran

Collection of Engaged Learning

Bighead carp and silver carp (Invader Species – Asian Carp) invaded the Illinois River waterway over a decade ago. Populations of these fishes have apparently grown dense in the lower and middle Illinois Rivers and both species are approaching the Chicago Area Waterway System (CAWS) and potentially making their way into Great Lakes. So far, positive DNA of Asian Carp has been found beyond the defensive electrical barrier, which means they have made their way to Great Lakes somehow. Asian Carp are fast growing, aggressive, and adaptable fish that are outcompeting native fish species for food and habitat in much …

On The Optimal Control Of The Free Boundary Problems For The Second Order Parabolic Equations. I. Well-Posedness And Convergence Of The Method Of Lines, Ugur G. Abdulla

Mathematics and System Engineering Faculty Publications

We develop a new variational formulation of the inverse Stefan problem, where information on the heat flux on the fi xed boundary is missing and must be found along with the temperature and free boundary. We employ optimal control framework, where boundary heat flux and free boundary are components of the control vector, and optimality criteria consists of the mini- mization of the sum of L2-norm declinations from the available measurement of the temperature flux on the fi xed boundary and available information on the phase transition temperature on the free boundary. This approach allows one to tackle situations when …

Number Theory Applications In Cryptography, Francesca Pizzigoni

Theses, Dissertations and Culminating Projects

This thesis provides a unique cryptosystem comprised of different number theory applications. We first consider the well-known Knapsack Problem and the resulting Knapsack Cryptosystem. It is known that when the Knapsack Problem involves a superincreasing sequence, the solution is easy to find. Two cryptosystems are designed and displayed in this thesis that allow two parties often called Alice and Bob use a common superincreasing sequence in the encryption and decryption process. They use this sequence and a variation of the Knapsack Cryptosystem to send and receive binary messages. The first cryptosystem assumes that Alice and Bob agree on a shared …

Common Misconceptions And Instructional Best Practices For Teaching Fractions To Students In Grades Three, Four, And Five, Dan Fairchild

Mathematics Graduate Theses

This research paper will identify common misconceptions related to the teaching and learning fractions for students in grades three, four, and five. Different fraction subconstructs will be identified and instructional best practices will be identified for the teaching and learning of comparing fractions, ordering fractions, adding fractions, and subtracting fractions.

Teaching Social Justice Mathematics In A Privileged Setting, Rick Mcnamee

Theses, Dissertations and Culminating Projects

This practitioner action research using qualitative techniques of gathering data looks at the experiences of students in a mostly white, upper-middle class suburb who enrolled in a class that integrated mathematics with social justice issues. The researcher designed the curriculum and co-taught the one semester course. The data were collected from pre-interviews, beginning and end of class questionnaires, quick writes, field notes, and end of class focus group interviews with all the students. The author chose a practitioner action research design because he wanted to be an integral part of the study. The cyclical nature of action research allowed him …

Proper Connection Of Bipartite Circulant Graphs, Melissa Marie Fuentes

Theses, Dissertations and Culminating Projects

The study of proper edge-colorings of graphs has been a popular topic in graph theory since the work of Vizing. While the proper edge-colorings of entire graphs was the topic of interest when the subject began decades ago, more recent works have focused on the study of properly colored subgraphs, as opposed to proper colorings of graphs as a whole. The types of properly colored subgraphs that we will be most concerned with are paths. The topic of finding certain types of properly colored paths within larger edge-colored graphs, though seemingly specific in nature, has been a topic of much …

Homological Algebra : Tor Functors, Betti Numbers, And Free Resolutions., Ian Philipp

College of Arts & Sciences Senior Theses

The topic of study for this project is homological algebra, a branch of mathematics with applications to a plethora of other branches of mathematics as well as sensor networks, signal processing, uid dynamics, particle physics, etc. The amount of literature written on this topic is vast and there are numerous open problems in homological algebra, but this project has a more modest focus. First, we will explain the fundamental terminology with several examples and later we will proceed to some results concerning certain rings and ideals, and then results about modules generated by zero divisors.

Characterizations Of Certain Recently Introduced Distributions, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

Various characterizations of the Beta Weibull Geometric distribution of Bidram et al. (2011), the New Generalized Exponential distribution of Bidram et al. (2012), and the Gamma Exponentiated Weibull distribution of Pinho et al. (2012) are presented. These characterizations are based on: (i) a simple relationship between two truncated moments (ii) certain functions of the nth order statistic, and (iii) certain functions of the 1st order statistics.

Split Abelian Chief Factors And First Degree Cohomology For Lie Algebras, Jorg Feldvoss, Salvatore Siciliano, Thomas Weigel

University Faculty and Staff Publications

In this paper we investigate the relation between the multiplicities of split abelian chief factors of finite-dimensional Lie algebras and first degree cohomology. In particular, we obtain a characterization of modular solvable Lie algebras in terms of the vanishing of first degree cohomology or in terms of the multiplicities of split abelian chief factors. The analogues of these results are well known in the modular representation theory of finite groups. An important tool in the proof of these results is a refinement of a non-vanishing theorem of Seligman for the first degree cohomology of non-solvable finite-dimensional Lie algebras in prime …

Comparing The Impact Of Traditional And Modeling College Algebra Courses On Student Performance In Survey Of Calculus, Jerry West

Graduate Theses and Dissertations

Students in higher education deserve opportunities to succeed and learning environments which maximize success. Mathematics courses can create a barrier for success for some students. College algebra is a course that serves as a gateway to required courses in many bachelor's degree programs. The content in college algebra should serve to maximize students' potential in utilizing mathematics and gaining skills required in subsequent math-based courses when necessary. The Committee for Undergraduate Programs in Mathematics has gone through extensive work to help mathematics departments reform their college algebra courses in order to help students gain interest in the utilization of mathematics …

On Toric Symmetry Of P1 X P2, Olivia D. Beckwith

HMC Senior Theses

Toric varieties are a class of geometric objects with a combinatorial structure encoded in polytopes. P1 x P2 is a well known variety and its polytope is the triangular prism. Studying the symmetries of the triangular prism and its truncations can lead to symmetries of the variety. Many of these symmetries permute the elements of the cohomology ring nontrivially and induce nontrivial relations. We discuss some toric symmetries of P1 x P2, and describe the geometry of the polytope of the corresponding blowups, and analyze the induced action on the cohomology ring. We exhaustively compute the toric symmetries of P1 …

Extortion And Evolution In The Iterated Prisoner's Dilemma, Michael J. Earnest

HMC Senior Theses

The Prisoner's Dilemma is a two player game where playing rationally leads to a suboptimal outcome for both players. The game is simple to analyze, but when it is played repeatedly, complex dynamics emerge. Recent research has shown the existence of extortionate strategies, which allow one player to win at least as much as the other. When one player plays such a strategy, the other must either decide to take a low payoff, or accede to the extortion, where they earn higher payoff, but their opponent receives a larger share. We investigate what happens when one player uses this strategy …

A New Optimization Algorithm For Single Hidden Layer Feedforward Neural Networks, Leong Kwan Li, Sally Shao, Ka-Fai Cedric Yiu

Mathematics and Statistics Faculty Publications

Feedforward neural networks are the most commonly used function approximation techniques in neural networks. By the universal approximation theorem, it is clear that a single-hidden layer feedforward neural network (FNN) is sufficient to approximate the corresponding desired outputs arbitrarily close. Some researchers use genetic algorithms (GAs) to explore the global optimal solution of the FNN structure. However, it is rather time consuming to use GA for the training of FNN. In this paper, we propose a new optimization algorithm for a single-hidden layer FNN. The method is based on the convex combination algorithm for massaging information in the hidden layer. …

Detectable Subclinical Myocardial Necrosis Is Associated With Cardiovascular Risk In Stable Patients With Diabetes, W.H. Wilson Tang, Yuping Wu, Earl B. Britt Jr., Naveed Iqbal, Stanley L. Hazen

Mathematics and Statistics Faculty Publications

OBJECTIVE: To investigate the relationship between different degrees of subclinical myocardial necrosis, glycemic control, and long-term adverse clinical outcomes within a stable patient population with diabetes mellitus. RESEARCH DESIGN AND METHODS: We examined 1,275 stable patients with diabetes mellitus undergoing elective diagnostic coronary angiography with cardiac troponin I (cTnI) levels below the diagnostic cut-off for defining myocardial infarction (MI) (<0.03 ng/mL). The relationship of subclinical myocardial necrosis (cTnI 0.009–0.029 ng/mL) with incident major adverse cardiovascular events (MACE; defined as any death, MI, or stroke) over 3 years of follow-up was examined. RESULTS: Subclinical myocardial necrosis was observed in 22% of patients. A strong association was observed between the magnitude of subclinical myocardial necrosis and risk of 3-year incident MACE (hazard ratio, 1.98; 95% confidence interval, 1.48–2.65; P < 0.001) and remained statistically significant even after adjustment for traditional risk factors, high-sensitivity C-reactive protein, and creatinine clearance. Only a weak correlation was observed between the presence of subclinical myocardial necrosis and either glycemic control (r = 0.06; P = 0.044 for hemoglobin A1c versus cTnI) or insulin resistance (r = 0.04; P = 0.094 for glucose-to-insulin ratio versus cTnI). CONCLUSIONS: The presence of detectable subclinical myocardial necrosis in stable patients with diabetes mellitus is associated with heightened long-term risk for MACE, independent of traditional risk factors and glycemic control.

General Bounds On The Downhill Domination Number In Graphs., William Jamieson

Undergraduate Honors Theses

A path π = (v₁, v₂,...v_k+1) in a graph G = (V,E) is a downhill path if for every i, 1 < i < k, deg(v_i) > deg(v_i+1), where deg(v_i) denotes the degree of vertex v_i ∊ V. The downhill domination number equals the minimum cardinality of a set S ⊂ V having the property that every vertex v ∊ V lies on a downhill path originating from some vertex in S. We investigate downhill domination numbers of graphs and give upper bounds. …

Variations Of The Combinatorial Game Tron, Miriam Parnes

Theses, Dissertations and Culminating Projects

The combinatorial game Tron is a two player game played on a graph, in which players move to adjacent vertices, but cannot move to any vertex which is currently occupied or which has been occupied by either player earlier in the course of the game. It was introduced by Hans Bodlaender, inspired by the Disney movie of the same name. Bodlaender and, later, Tillmann Miltzow considered the complexity of the question of whether a player has a winning strategy in the game. Miltzow also considered an extremal question regarding the ratio of the vertices taken by the second player over …

Dirichlet's Theorem And Applications, Nicholas Stanford

Honors Scholar Theses

Dirichlet's theorem states that there exist an infinite number of primes in an arithmetic progression a + mk when a and m are relatively prime and k runs over the positive integers. While a few special cases of Dirichlet's theorem, such as the arithmetic progression 2 + 3k, can be settled by elementary methods, the proof of the general case is much more involved. Analysis of the Riemann zeta-function and Dirichlet L-functions is used.

The proof of Dirichlet's theorem suggests a method for defining a notion of density of a set of primes, called its Dirichlet density, …

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.

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 Mathematical Model For Antibiotic Resistance In A Hospital Setting With A Varying Population, Edward H. Snyder

Electronic Theses and Dissertations

Antibiotic-resistant bacteria(ARB) is causing increased health risk and cost to society. Mathematical models have been developed to study the transmission of resistant bacteria and the efficacy of preventive measures to slow its spread within a hospital setting. The majority of these models have assumed a constant total hospital population with the admission and discharge rates being equal throughout the duration. But a typical hospital population varies from day to day and season to season. In this thesis, we apply variable admission and discharge daily rates to existing deterministic and stochastic models which examine the transmission of single and dual resistant …

Students Rise To The Challenge Of Modeling Yeast Growth Despite Sour Hiccups From Imperfect Data, Alicia Caldwell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Students rarely receive the opportunity to experience a learning activity involving mathematical modeling. This paper describes a lab in which students in an Applied Mathematics in Biology course observe the growth of Saccharomyces cerevisiae, a yeast strain, in differing sugar concentrations for use in learning modeling. They parameterized the logistic equation and an alternate model, which they themselves constructed, based on the data they collected. I participated in this lab as a student in 2012 then observed and reviewed the work of other students involved. I found that students gained a deeper understanding of limiting factors and the role of …

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