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2015

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Articles 631 - 660 of 1160

Full-Text Articles in Mathematics

Mathematical Modeling Of The Imported Malaria In The United Arab Emirates, Fatima Hassan Ali Alawadhi Apr 2015

Mathematical Modeling Of The Imported Malaria In The United Arab Emirates, Fatima Hassan Ali Alawadhi

Theses

Although the UAE was certified to be free of local malaria transmission cases in 2007, the increased number of imported malaria cases in recent years required the attention of the public health professionals. The aim of this work is to study, via mathematical modeling, the impact of imported malaria cases on the population of the UAE. The nature of the health policies in the UAE imposes on us a model that classifies the living population of the UAE in two categories. The local population, who represent the permanent residents that do not have any health requirement for their residency, and …

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On The Fattening Of Lines In P3, Mike Janssen Apr 2015

On The Fattening Of Lines In P3, Mike Janssen

Faculty Work Comprehensive List

We follow the lead of Bocci and Chiantini and show how differences in the invariant alpha can be used to classify certain classes of subschemes of P^3. Specifically, we will seek to classify arithmetically Cohen-Macaulay codimension 2 subschemes of P^3 in the manner Bocci and Chiantini classified points in P^2. The first section will seek to motivate our consideration of the invariant alpha by relating it to the Hilbert function and gamma, following the work of Bocci and Chiantini, and Dumnicki, et. al. The second section will contain our results classifying arithmetically Cohen-Macaulay codimension 2 subschemes of P^3. This work …

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The Catalan Case Of Armstrong's Conjecture On Simultaneous Core Partitions Read More: Https://Epubs.Siam.Org/Doi/10.1137/130950318, Richard Stanley, Fabrizio Zanello Mar 2015

The Catalan Case Of Armstrong's Conjecture On Simultaneous Core Partitions Read More: Https://Epubs.Siam.Org/Doi/10.1137/130950318, Richard Stanley, Fabrizio Zanello

Department of Mathematical Sciences Publications

A beautiful recent conjecture of D. Armstrong predicts the average size of a partition that is simultaneously an s-core and a t-core, where s and t are coprime. Our goal is to prove this conjecture when t = s + 1. These simultaneous (s, s + 1)-core partitions, which are enumerated by Catalan numbers, have average size ((s+1)/3)/2.

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Transpose Symmetry Groups Of Noninvertible Polynomials, Nathan Cordner, Dr. Tyler Jarvis Mar 2015

Transpose Symmetry Groups Of Noninvertible Polynomials, Nathan Cordner, Dr. Tyler Jarvis

Journal of Undergraduate Research

Introduction Mirror symmetry is an area of mathematical research that stems from theoretical physics, particularly from string theory. Solutions of problems in mirror symmetry yield not only interesting mathematical results, but also have important theoretical implications for high energy particle physics.

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Essays On Air Pollution, Global Warming And Agriculture Productivity., Ridhima Gupta Dr. Mar 2015

Essays On Air Pollution, Global Warming And Agriculture Productivity., Ridhima Gupta Dr.

Doctoral Theses

This dissertation consists of three chapters, each of which deals with a particular aspect of environmental policy. The first chapter focuses on the determinants of open-field burning of rice-residue with the aim of analysing possibilities for its regulation. Open field burning is the second-largest contributor to black carbon in South Asia, the second most important greenhouse agent after carbon dioxide. Thus, dealing with the problem of burning of rice residue will tackle a significant proportion of the black carbon emissions released into the atmosphere. The third chapter proposes a new approach for estimating the contribution of agricultural fires to atmospheric …

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Byu Computational Number Theory Research Group David Cardon, Darrin Doud, Paul Jenkins, And Pace Nielsen, Pace Nielsen Mar 2015

Byu Computational Number Theory Research Group David Cardon, Darrin Doud, Paul Jenkins, And Pace Nielsen, Pace Nielsen

Journal of Undergraduate Research

In the years 2013-2014 we held a weekly seminar in which every supported student gave presentations at least once (but usually twice or more) per semester. This gave the students opportunities to learn and develop presentations skills, which will help them later in their careers. It also gave them opportunities to work together in a tight-knit group setting. This learning was augmented by regular, one-on-one weekly meetings with their advisors. Many of the students wrote professional research papers published in peer-reviewed journals, presented their research at conferences, and many won prestigious university and even national awards.

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Leveraging Mosts (Mathematically Significant Pedagogical Opportunities To Build On Student Thinking), Keith R. Leatham, Blake E. Peterson Mar 2015

Leveraging Mosts (Mathematically Significant Pedagogical Opportunities To Build On Student Thinking), Keith R. Leatham, Blake E. Peterson

Journal of Undergraduate Research

Phase 1, Goal 1: Purposefully create a data set of videotapes and transcripts of secondary classroom mathematics discourse that reflects the student mathematical thinking that can occur in diverse classrooms.

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Recent Advances In Compressed Sensing: Discrete Uncertainty Principles And Fast Hyperspectral Imaging, Megan E. Lewis Mar 2015

Recent Advances In Compressed Sensing: Discrete Uncertainty Principles And Fast Hyperspectral Imaging, Megan E. Lewis

Theses and Dissertations

Compressed sensing is an important field with continuing advances in theory and applications. This thesis provides contributions to both theory and application. Much of the theory behind compressed sensing is based on uncertainty principles, which state that a signal cannot be concentrated in both time and frequency. We develop a new discrete uncertainty principle and use it to demonstrate a fundamental limitation of the demixing problem, and to provide a fast method of detecting sparse signals. The second half of this thesis focuses on a specific application of compressed sensing: hyperspectral imaging. Conventional hyperspectral platforms require long exposure times, which …

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The Riemann Curvature Tensor, Its Invariants, And Their Use In The Classification Of Spacetimes, Jesse Hicks Mar 2015

The Riemann Curvature Tensor, Its Invariants, And Their Use In The Classification Of Spacetimes, Jesse Hicks

Presentations and Publications

The equivalence problem in general relativity is to determine whether two solutions of the Einstein field equations are isometric. Petrov has given a classification of metrics according to their isometry algebras. This talk discusses the use of the Petrov classification scheme, together with the use of scalar curvature invariants, to address the equivalence problem. These are the slides for a presentation at the Mathematics Association of America Spring 2015 conference at Brigham Young University.

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Alan Turing: The Man Behind The Machine, Christopher D. Goff Mar 2015

Alan Turing: The Man Behind The Machine, Christopher D. Goff

College of the Pacific Faculty Presentations

No abstract provided.

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Computational Modeling Of Wave Propagation In Metamaterials, Shue-Sum Chow Mar 2015

Computational Modeling Of Wave Propagation In Metamaterials, Shue-Sum Chow

Journal of Undergraduate Research

The project is concerned with the study of wave propagation in metamaterials. We recall the work plan described in the original proposal and provide an evaluation of the academic objectives.

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Labeling And Comparison Of Isomeric Tree-Like Polyphenyl Systems, Tabitha Williford, Alex Collins, Shainaz Landge, Hua Wang Mar 2015

Labeling And Comparison Of Isomeric Tree-Like Polyphenyl Systems, Tabitha Williford, Alex Collins, Shainaz Landge, Hua Wang

Mathematical Sciences: Faculty Publications

Tree-like polyphenyl systems form an important class of compounds in chemistry, in particular material science and polymers. The importance can be seen in LEDs, transmitters, and electronics. In recent years, many extremal results regarding such systems under specific constraints have been reported. More specifically are the sub-categories of such systems with extremal Wiener indices. In this article, we provide a labelling of the vertices on each hexagon (i.e., the corresponding benzene ring), which facilitates the illustration of a treelike polyphenyl system with its corresponding tree structure. This approach helps to characterize the extremal tree-like polyphenyl systems with respect to the …

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On Pi Day, A Serving Of Why We Need Math, Darren B. Glass Mar 2015

On Pi Day, A Serving Of Why We Need Math, Darren B. Glass

Math Faculty Publications

Today, our Facebook feeds will be peppered with references to Pi Day, a day of celebration that has long been acknowledged by math fans and that Congress recognized in 2009. Every high schooler learns that pi is the ratio of the circumference of a circle to its diameter and that its decimal expansion begins 3.14 and goes on infinitely without repeating. [excerpt]

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Defining The Transpose Group In Landau-Ginzburg Mirror Symmetry, Lisa Bendall, Dr. Tyler Jarvis Mar 2015

Defining The Transpose Group In Landau-Ginzburg Mirror Symmetry, Lisa Bendall, Dr. Tyler Jarvis

Journal of Undergraduate Research

Introduction. Mirror symmetry is a phenomenon first observed in theoretical physics, which has garnered interest among mathematicians. The Landau-Ginzburg mirror symmetry conjecture proposes two algebraic structures which are isomorphic, or in some sense “mirror” each other. These structures are built from polynomials and corresponding symmetry groups.

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Why It Is Important To Precisiate Goals, Olga Kosheleva, Vladik Kreinovich, Hung T. Nguyen Mar 2015

Why It Is Important To Precisiate Goals, Olga Kosheleva, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

After Zadeh and Bellman explained how to optimize a function under fuzzy constraints, there have been many successful applications of this optimization. However, in many practical situations, it turns out to be more efficient to precisiate the objective function before performing optimization. In this paper, we provide a possible explanation for this empirical fact.

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Simple Linear Interpolation Explains All Usual Choices In Fuzzy Techniques: Membership Functions, T-Norms, T-Conorms, And Defuzzification, Vladik Kreinovich, Jonathan Quijas, Esthela Gallardo, Caio De Sa Lopes, Olga Kosheleva, Shahnaz Shahbazova Mar 2015

Simple Linear Interpolation Explains All Usual Choices In Fuzzy Techniques: Membership Functions, T-Norms, T-Conorms, And Defuzzification, Vladik Kreinovich, Jonathan Quijas, Esthela Gallardo, Caio De Sa Lopes, Olga Kosheleva, Shahnaz Shahbazova

Departmental Technical Reports (CS)

Most applications of fuzzy techniques use piece-wise linear (triangular or trapezoid) membership functions, min or product t-norms, max or algebraic sum t-conorms, and centroid defuzzification. Similarly, most applications of interval-valued fuzzy techniques use piecewise-linear lower and upper membership functions. In this paper, we show that all these choices can be explained as applications of simple linear interpolation.

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Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos Mar 2015

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Presentations and Publications

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and elec- tromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equa- tions are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Ge- ometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and for- mulas for constructing …

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Sandpiles, Spanning Trees, And Plane Duality, Melody Chan, Darren B. Glass, Matthew Macauley, David Perkinson, Caryn Werner, Qiaoyu Yang Mar 2015

Sandpiles, Spanning Trees, And Plane Duality, Melody Chan, Darren B. Glass, Matthew Macauley, David Perkinson, Caryn Werner, Qiaoyu Yang

Math Faculty Publications

Let G be a connected, loopless multigraph. The sandpile group of G is a finite abelian group associated to G whose order is equal to the number of spanning trees in G. Holroyd et al. used a dynamical process on graphs called rotor-routing to define a simply transitive action of the sandpile group of G on its set of spanning trees. Their definition depends on two pieces of auxiliary data: a choice of a ribbon graph structure on G, and a choice of a root vertex. Chan, Church, and Grochow showed that if G is a planar ribbon graph, it …

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Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean Mar 2015

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

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Lai’S Conditions For Spanning And Dominating Closed Trails, Wei-Guo Chen, Zhi-Hong Chen, Mei Lu Mar 2015

Lai’S Conditions For Spanning And Dominating Closed Trails, Wei-Guo Chen, Zhi-Hong Chen, Mei Lu

Scholarship and Professional Work - LAS

No abstract provided.

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Analysing Systemic Risk Contribution Using A Closed Formula For Conditional Value At Risk Through Copula, Brice Hakwa, Manfred Jäger-Ambrożewicz, Barbara Rüdiger Mar 2015

Analysing Systemic Risk Contribution Using A Closed Formula For Conditional Value At Risk Through Copula, Brice Hakwa, Manfred Jäger-Ambrożewicz, Barbara Rüdiger

Communications on Stochastic Analysis

No abstract provided.

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Mathematical Formulation Of An Optimal Execution Problem With Uncertain Market Impact, Kensuke Ishitani, Takashi Kato Mar 2015

Mathematical Formulation Of An Optimal Execution Problem With Uncertain Market Impact, Kensuke Ishitani, Takashi Kato

Communications on Stochastic Analysis

No abstract provided.

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On A Nonsymmetric Ornstein-Uhlenbeck Semigroup And Its Generator, Yong Chen Mar 2015

On A Nonsymmetric Ornstein-Uhlenbeck Semigroup And Its Generator, Yong Chen

Communications on Stochastic Analysis

No abstract provided.

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Existence Of Lévy's Area And Pathwise Integration, Peter Imkeller, David J Prömel Mar 2015

Existence Of Lévy's Area And Pathwise Integration, Peter Imkeller, David J Prömel

Communications on Stochastic Analysis

No abstract provided.

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Branching Particle Systems And Compound Poisson Processes Related To Pólya-Aeppli Distributions, Richard B Paris, Vladimir Vinogradov Mar 2015

Branching Particle Systems And Compound Poisson Processes Related To Pólya-Aeppli Distributions, Richard B Paris, Vladimir Vinogradov

Communications on Stochastic Analysis

No abstract provided.

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Hitting Times For Bessel Processes, Gerardo Hernández-Del-Valle, Carlos G Pacheco Mar 2015

Hitting Times For Bessel Processes, Gerardo Hernández-Del-Valle, Carlos G Pacheco

Communications on Stochastic Analysis

No abstract provided.

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Estimation Of Heterogeneous Panels With Structural Breaks, Badi Baltagi Mar 2015

Estimation Of Heterogeneous Panels With Structural Breaks, Badi Baltagi

Center for Policy Research

This paper extends Pesaran's (2006) work on common correlated effects (CCE) estimators for large heterogeneous panels with a general multifactor error structure by allowing for unknown common structural breaks. Structural breaks due to new policy implementation or major technological shocks, are more likely to occur over a longer time span. Consequently, ignoring structural breaks may lead to inconsistent estimation and invalid inference. We propose a general framework that includes heterogeneous panel data models and structural break models as special cases. The least squares method proposed by Bai (1997a, 2010) is applied to estimate the common change points, and the consistency …

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Analysing Student Work Involving Geometric Concepts, Hyunyi Jung Mar 2015

Analysing Student Work Involving Geometric Concepts, Hyunyi Jung

Mathematics, Statistics and Computer Science Faculty Research and Publications

Hyunyi Jung reflects on why students struggle to understand trigonometry.

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Integrating Data Transformation In Principal Components Analysis, Mehdi Maadooliat, Jianhua Z. Huang, Jianhua Hu Mar 2015

Integrating Data Transformation In Principal Components Analysis, Mehdi Maadooliat, Jianhua Z. Huang, Jianhua Hu

Mathematics, Statistics and Computer Science Faculty Research and Publications

Principal component analysis (PCA) is a popular dimension-reduction method to reduce the complexity and obtain the informative aspects of high-dimensional datasets. When the data distribution is skewed, data transformation is commonly used prior to applying PCA. Such transformation is usually obtained from previous studies, prior knowledge, or trial-and-error. In this work, we develop a model-based method that integrates data transformation in PCA and finds an appropriate data transformation using the maximum profile likelihood. Extensions of the method to handle functional data and missing values are also developed. Several numerical algorithms are provided for efficient computation. The proposed method is illustrated …

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Open And Dense Topological Transitivity Of Extensions By Non-Compact Fiber Of Hyperbolic Systems: A Review, Viorel Nitica, Andrei Török Mar 2015

Open And Dense Topological Transitivity Of Extensions By Non-Compact Fiber Of Hyperbolic Systems: A Review, Viorel Nitica, Andrei Török

Mathematics Faculty Publications

Currently, there is great renewed interest in proving the topological transitivity of various classes of continuous dynamical systems. Even though this is one of the most basic dynamical properties that can be investigated, the tools used by various authors are quite diverse and are strongly related to the class of dynamical systems under consideration. The goal of this review article is to present the state of the art for the class of Hölder extensions of hyperbolic systems with non-compact connected Lie group fiber. The hyperbolic systems we consider are mostly discrete time. In particular, we address the stability and genericity …

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