Mathematics Commons^™

A Combinatorial Formula For Kazhdan–Lusztig Polynomials Of Sparse Paving Matroids, George Nasr

Department of Mathematics: Dissertations, Theses, and Student Research

We present a combinatorial formula using skew Young tableaux for the coefficients of Kazhdan–Lusztig polynomials for sparse paving matroids. These matroids are known to be logarithmically almost all matroids, but are conjectured to be almost all matroids. We also show the positivity of these coefficients using our formula. In special cases, such as for uniform matroids, our formula has a nice combinatorial interpretation.

Advisors: Kyungyong Lee and Jamie Radcliffe

Empirical Bayes Estimates For The Reproduction Number Of Epidemics, Elijah Lee Hight

Theses and Dissertations

Epidemic outbreaks can be modelled as a branching process in which the total progeny or outbreak size, follows a Borel-Tanner (BT) distribution. Following a procedure described by Liang (2009), we construct empirical Bayes estimates for when the initial number of infected is a specified value r. Following the construction, we then simulate data and perform a numerical study, assuming BT distribution for the parameter θ, the reproduction number, with an initial outbreak size of three. Simulation results indicate that the empirical estimator suffers from “jumpiness.” We then proceed to monotonize the empirical estimate via a method outlined by Houwelingen (1979). …

Elliptic Curves And Their Practical Applications, Henry H. Hayden Iv

Graduate Theses/Dissertations

Finding rational points that satisfy functions known as elliptic curves induces a finitely-generated abelian group. Such functions are powerful tools that were used to solve Fermat's Last Theorem and are used in cryptography to send private keys over public systems. Elliptic curves are also useful in factoring and determining primality.

Partially Oriented 6-Star Decomposition Of Some Complete Mixed Graphs, Kazeem A. Kosebinu

Electronic Theses and Dissertations

Let $M_v$ denotes a complete mixed graph on $v$ vertices, and let $S_6^i$ denotes the partial orientation of the 6-star with twice as many arcs as edges. In this work, we state and prove the necessary and sufficient conditions for the existence of $\lambda$-fold decomposition of a complete mixed graph into $S_6^i$ for $i\in\{1,2,3,4\}$. We used the difference method for our proof in some cases. We also give some general sufficient conditions for the existence of $S_6^i$-decomposition of the complete bipartite mixed graph for $i\in\{1,2,3,4\}$. Finally, this work introduces the decomposition of a complete mixed graph with a hole into …

Simultaneous Forecasting Of Yield Curves For Multiple Zero-Coupon Bonds Using The Heath-Jarrow-Morton Model, Ebenezer Nkum

Open Access Theses & Dissertations

Market diversification is a strategy according to which a company seeks growth by addingproducts and markets that are in a certain sense "uncorrelated" to its existing products and markets. Bonds play a major role in a well-balanced diversified portfolio because of their low correlation to other asset classes. While the correlations vary widely over time, bonds are not highly correlated with any other asset classes. Even in the simplest diversified portfolio, bonds can reduce volatility due to their low or negative correlation with stocks. Because companies can create robust diversified portfolios with bonds it is imperative that different bonds are …

Towards Reinforcement Learning Driven Mesh Adaptivity For Second Order Elliptic Problems, Augustine Twumasi

Open Access Theses & Dissertations

Adaptive mesh refinement techniques have become an indispensable tool in achieving accurate and efficiently computed solutions to problems which require impractically fine uniform meshes to obtain an accurate approximation. The adaptive algorithm involves a recursive application of SOLVE-ESTIMATE-MARK-REFINE steps where in particular the step `ESTIMATE' involves computing a posteriori error estimator based on only the numerical solution and the data of the problem. Over the years, several a posteriori error estimators have been developed and successfully applied but often times, the choice of estimator is ill suited for the problem at hand. In this research, we present two estimators namely …

A Novel Numerical Method For Solving Fractional Diffusion-Wave And Nonlinear Fredholm And Volterra Integral Equations With Zero Absolute Error, Mutaz Mohammad, Alexandre Trounev, Mohammed Alshbool

All Works

In this work, a new numerical method for the fractional diffusion-wave equation and nonlinear Fredholm and Volterra integro-differential equations is proposed. The method is based on Euler wavelet approximation and matrix inversion of an M × M collocation points. The proposed equations are presented based on Caputo fractional derivative where we reduce the resulting system to a system of algebraic equations by implementing the Gaussian quadrature discretization. The reduced system is generated via the truncated Euler wavelet expansion. Several examples with known exact solutions have been solved with zero absolute error. This method is also applied to the Fredholm and …

Multilateration Index., Chip Lynch

Electronic Theses and Dissertations

We present an alternative method for pre-processing and storing point data, particularly for Geospatial points, by storing multilateration distances to fixed points rather than coordinates such as Latitude and Longitude. We explore the use of this data to improve query performance for some distance related queries such as nearest neighbor and query-within-radius (i.e. “find all points in a set P within distance d of query point q”). Further, we discuss the problem of “Network Adequacy” common to medical and communications businesses, to analyze questions such as “are at least 90% of patients living within 50 miles of a covered emergency …

Sexual Dimorphism In The Functional Development Of The Cochlear Amplifier In Humans, Sri Mishra, Samantha Zambrano, Hansapani Rodrigo

School of Mathematical & Statistical Sciences Faculty Publications

Objectives:

Otoacoustic emissions, a byproduct of active cochlear mechanisms, exhibit a higher magnitude in females than in males. The relatively higher levels of androgen exposure in the male fetus are thought to cause this difference. Postnatally, the onset of puberty is also associated with the androgen surge in males. In this study, we investigated sexual dimorphism in age-related changes in stimulus-frequency otoacoustic emissions for children.

Design:

In a retrospective design, stimulus-frequency otoacoustic emissions were analyzed from a cross-sectional sample of 170 normal-hearing children (4 to 12 years) and 67 young adults. Wideband acoustic immittance and efferent inhibition measures were analyzed …

Node Generation For Rbf-Fd Methods By Qr Factorization, Tony Liu, Rodrigo B. Platte

Faculty Publications

Polyharmonic spline (PHS) radial basis functions (RBFs) have been used in conjunction with polynomials to create RBF finite-difference (RBF-FD) methods. In 2D, these methods are usually implemented with Cartesian nodes, hexagonal nodes, or most commonly, quasi-uniformly distributed nodes generated through fast algorithms. We explore novel strategies for computing the placement of sampling points for RBF-FD methods in both 1D and 2D while investigating the benefits of using these points. The optimality of sampling points is determined by a novel piecewise-defined Lebesgue constant. Points are then sampled by modifying a simple, robust, column-pivoting QR algorithm previously implemented to find sets of …

The Color Number Of Cubic Graphs Having A Spanning Tree With A Bounded Number Of Leaves, Analen A. Malnegro, Gina A. Malacas, Kenta Ozeki

Theory & Applications of Graphs

The color number c(G) of a cubic graphG is the minimum cardinality of a color class of a proper 4-edge-coloring of G. It is well-known that every cubic graph G satisfies c(G) = 0 if G

Contributions To The Teaching And Learning Of Fluid Mechanics, Ashwin Vaidya

Department of Mathematics Faculty Scholarship and Creative Works

This issue showcases a compilation of papers on fluid mechanics (FM) education, covering different sub topics of the subject. The success of the first volume [1] prompted us to consider another follow-up special issue on the topic, which has also been very successful in garnering an impressive variety of submissions.

As a classical branch of science, the beauty and complexity of fluid dynamics cannot be overemphasized. This is an extremely well-studied subject which has now become a significant component of several major scientific disciplines ranging from aerospace engineering, astrophysics, atmospheric science (including climate modeling), biological and biomedical science …

Probability Distributions For Elliptic Curves In The Cgl Hash Function, Dhruv Bhatia, Kara Fagerstrom, Max Watson

Mathematical Sciences Technical Reports (MSTR)

Hash functions map data of arbitrary length to data of predetermined length. Good hash functions are hard to predict, making them useful in cryptography. We are interested in the elliptic curve CGL hash function, which maps a bitstring to an elliptic curve by traversing an inputdetermined path through an isogeny graph. The nodes of an isogeny graph are elliptic curves, and the edges are special maps betwixt elliptic curves called isogenies. Knowing which hash values are most likely informs us of potential security weaknesses in the hash function. We use stochastic matrices to compute the expected probability distributions of the …

Trilinear Smoothing Inequalities And A Variant Of The Triangular Hilbert Transform, Michael Christ, Polona Durcik, Joris Roos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Lebesgue space inequalities are proved for a variant of the triangular Hilbert transform involving curvature. The analysis relies on a crucial trilinear smoothing inequality developed herein, and on bounds for an anisotropic variant of the twisted paraproduct.

The trilinear smoothing inequality also leads to Lebesgue space bounds for a corresponding maximal function and a quantitative nonlinear Roth-type theorem concerning patterns in the Euclidean plane.

Fourth Voices Conference On Teaching Stem With Song, Lawrence M. Lesser

Journal of Humanistic Mathematics

The fourth VOICES (Virtual Ongoing Interdisciplinary Collaborations on Educating with Song) conference will be held September 26, 2021, with its Sunday date especially targeting those whose teaching schedule precludes attendance on a weekday. This online-only conference explores the use of song to teach STEM content at the college or secondary school level and will include reviewed interactive sessions, video-posters, and discussions of interest to both practitioners and researchers.

An Interview With The (Other) Corona Graph, Bonnie Jacob, Jobby Jacob

Journal of Humanistic Mathematics

The following is an interview, conducted in April 2021, with a graph product known as the corona graph. Disclaimer: The views expressed herein are not ours. Actually, this entire interview is fiction, other than the mathematics, of course.

The Music Is All That Counts! A Poem-Collage Pair Created During The Pandemic, Sarah Glaz, Mark Sanders

Journal of Humanistic Mathematics

The poem-collage pair presented here is a work of collaboration between the mathematician and poet, Sarah Glaz, and the collage and ceramic artist, Mark Sanders. The piece is part of their larger joint poem-collage project involving the history of mathematics. Created at the height of the pandemic, the poem-collage pair reflects the reality of living during a plague and embodies the solace offered by long-distance collaboration and by the arts. Included as background is a brief discussion on the history and mathematics involved, information about Sarah’s poem and Mark’s collage, and a reflection on how the pandemic influenced both the …

Letters From Incompleteness, Jonah Howell

Journal of Humanistic Mathematics

In a series of letters to a faraway lover, an unnamed narrator attempts to make sense of his own internal struggles by fixating on the strange death of Kurt Gödel.

A Life Cut Short, Cacey L. Wells

Journal of Humanistic Mathematics

Connecting scholars and students with the human side of mathematics is critical. This poem about Évariste Galois provides a synopsis of his controversial life, while also providing details into his life that some may not be familiar with.

Asymptotic Dream, Oscar Gonzalez

Journal of Humanistic Mathematics

A love poem about breaching mathematical limits, inspired by the tragic beauty of calculus.