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Full-Text Articles in Physical Sciences and Mathematics

A Quantitative Study Of The Deployment Of The Sender Policy Framework, Eunice Zsu Tan Oct 2018

A Quantitative Study Of The Deployment Of The Sender Policy Framework, Eunice Zsu Tan

All Theses and Dissertations

Email has become a standard form of communication between businesses. With the prevalent use of email as a form of communication between businesses and customers, phishing emails have emerged as a popular social engineering approach. With phishing, attackers trick users into divulging their personal information through email spoofing. Thus, it is imperative to verify the sender of an email. Anti-spoofing mechanisms such as the Sender Policy Framework (SPF) have been developed as the first line of defense against spoofing by validating the source of an email as well as the presenting options of how to handle emails that fail to ...


Certificate Revocation Table: Leveraging Locality Of Reference In Web Requests To Improve Tls Certificate Revocation, Luke Austin Dickinson Oct 2018

Certificate Revocation Table: Leveraging Locality Of Reference In Web Requests To Improve Tls Certificate Revocation, Luke Austin Dickinson

All Theses and Dissertations

X.509 certificate revocation defends against man-in-the-middle attacks involving a compromised certificate. Certificate revocation strategies face scalability, effectiveness, and deployment challenges as HTTPS adoption rates have soared. We propose Certificate Revocation Table (CRT), a new revocation strategy that is competitive with or exceeds alternative state-of-the-art solutions in effectiveness, efficiency, certificate growth scalability, mass revocation event scalability, revocation timeliness, privacy, and deployment requirements. The CRT periodically checks the revocation status of X.509 certificates recently used by an organization, such as clients on a university's private network. By prechecking the revocation status of each certificate the client is likely to ...


Adding Limit Points To Bass-Serre Graphs Of Groups, Alexander Jin Shumway Jul 2018

Adding Limit Points To Bass-Serre Graphs Of Groups, Alexander Jin Shumway

All Theses and Dissertations

We give a brief overview of Bass-Serre theory and introduce a method of adding a limit point to graphs of groups. We explore a basic example of this method, and find that while the fundamental theorem of Bass-Serre theory no longer applies in this case we still recover a group action on a covering space of sorts with a subgroup isomorphic to the fundamental group of our new base space with added limit point. We also quantify how much larger the fundamental group of a graph of groups becomes after this construction, and discuss the effects of adding and identifying ...


Congruences For Fourier Coefficients Of Modular Functions Of Levels 2 And 4, Eric Brandon Moss Jul 2018

Congruences For Fourier Coefficients Of Modular Functions Of Levels 2 And 4, Eric Brandon Moss

All Theses and Dissertations

We give congruences modulo powers of 2 for the Fourier coefficients of certain level 2 modular functions with poles only at 0, answering a question posed by Andersen and Jenkins. The congruences involve a modulus that depends on the binary expansion of the modular form's order of vanishing at infinity. We also demonstrate congruences for Fourier coefficients of some level 4 modular functions.


Data Assimilation In The Boussinesq Approximation For Mantle Convection, Shane Alexander Mcquarrie Jul 2018

Data Assimilation In The Boussinesq Approximation For Mantle Convection, Shane Alexander Mcquarrie

All Theses and Dissertations

Many highly developed physical models poorly approximate actual physical systems due to natural random noise. For example, convection in the earth's mantle—a fundamental process for understanding the geochemical makeup of the earth's crust and the geologic history of the earth—exhibits chaotic behavior, so it is difficult to model accurately. In addition, it is impossible to directly measure temperature and fluid viscosity in the mantle, and any indirect measurements are not guaranteed to be highly accurate. Over the last 50 years, mathematicians have developed a rigorous framework for reconciling noisy observations with reasonable physical models, a technique ...


An Algorithm For Symbolic Computing Of Singular Limits Of Dynamical Systems, Dane Jordan Bjork Jul 2018

An Algorithm For Symbolic Computing Of Singular Limits Of Dynamical Systems, Dane Jordan Bjork

All Theses and Dissertations

The manifold boundary approximation method, MBAM is a new technique used in approximating systems of equations using parameter reduction. This method and other approximation methods are introduced and described. Several current issues in performing MBAM are discussed in further detail. These issues significantly slow down the process of MBAM and create a barrier of entry for those wishing to use the method without a strong background in mathematics. A solution is proposed to automatically reparameterize models and evaluate specific types of variables approaching limits -- significantly speeding up the process of MBAM. An implementation of the solution is discussed.


Machine Learning For Inspired, Structured, Lyrical Music Composition, Paul Mark Bodily Jul 2018

Machine Learning For Inspired, Structured, Lyrical Music Composition, Paul Mark Bodily

All Theses and Dissertations

Computational creativity has been called the "final frontier" of artificial intelligence due to the difficulty inherent in defining and implementing creativity in computational systems. Despite this difficulty computer creativity is becoming a more significant part of our everyday lives, in particular music. This is observed in the prevalence of music recommendation systems, co-creational music software packages, smart playlists, and procedurally-generated video games. Significant progress can be seen in the advances in industrial applications such as Spotify, Pandora, Apple Music, etc., but several problems persist. Of more general interest, however, is the question of whether or not computers can exhibit autonomous ...


Finding Torsion-Free Groups Which Do Not Have The Unique Product Property, Lindsay Jennae Soelberg Jul 2018

Finding Torsion-Free Groups Which Do Not Have The Unique Product Property, Lindsay Jennae Soelberg

All Theses and Dissertations

This thesis discusses the Kaplansky zero divisor conjecture. The conjecture states that a group ring of a torsion-free group over a field has no nonzero zero divisors. There are situations for which this conjecture is known to hold, such as linearly orderable groups, unique product groups, solvable groups, and elementary amenable groups. This paper considers the possibility that the conjecture is false and there is some counterexample in existence. The approach to searching for such a counterexample discussed here is to first find a torsion-free group that has subsets A and B such that AB has no unique product. We ...


Euclidean Domains, Vandy Jade Tombs Jul 2018

Euclidean Domains, Vandy Jade Tombs

All Theses and Dissertations

In the usual definition of a Euclidean domain, a ring has a norm function whose codomain is the positive integers. It was noticed by Motzkin in 1949 that the codomain could be replaced by any well-ordered set. This motivated the study of transfinite Euclidean domains in which the codomain of the norm function is replaced by the class of ordinals. We prove that there exists a (transfinitely valued) Euclidean Domain with Euclidean order type for every indecomposable ordinal. Modifying the construction, we prove that there exists a Euclidean Domain with no multiplicative norm. Following a definition of Clark and Murty ...


Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence Jul 2018

Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence

All Theses and Dissertations

Energy-based acoustic quantities provide vital information about acoustic fields and the characterization of acoustic sources. Recently, the phase and amplitude gradient estimator (PAGE) method has been developed to reduce error and extend bandwidth of energy-based quantity estimates. To inform uses and applications of the method, analytical and experimental characterizations of the method are presented. Analytical PAGE method bias errors are compared with those of traditional estimation for two- and three-microphone one-dimensional probes. For a monopole field when phase unwrapping is possible, zero bias error is achieved for active intensity using three-microphone PAGE and for specific acoustic impedance using two-microphone PAGE ...


Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle Jul 2018

Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle

All Theses and Dissertations

We create a dual-species ultracold neutral plasma (UNP) by photo-ionizing Yb and Ca atoms in a dual-species magneto-optical trap. Unlike single-species UNP expansion, these plasmas are well outside of the collisionless (Vlasov) approximation. We observe the mutual interaction of the Yb and Ca ions by measuring the velocity distribution for each ion species separately. We model the expansion using a fluid code including ion-ion friction and compare with experimental results to obtain a value of the Coulomb logarithm of Λ= 0.04.


The Arithmetic Of Modular Grids, Grant Steven Molnar Jul 2018

The Arithmetic Of Modular Grids, Grant Steven Molnar

All Theses and Dissertations

Let Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic weight modular forms with poles only at the cusp (∞), and let widehat Mk(∞) (Gamma, nu) subseteq Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic modular forms in Mk(∞) (Gamma, nu) which vanish at every cusp other than (∞). We construct canonical bases for these spaces in terms of Maass--Poincaré series, and show that the coefficients of these bases satisfy Zagier duality.


Application Of The Entropy Concept To Thermodynamics And Life Sciences: Evolution Parallels Thermodynamics, Cellulose Hydrolysis Thermodynamics, And Ordered And Disordered Vacancies Thermodynamics, Marko Popovic Jun 2018

Application Of The Entropy Concept To Thermodynamics And Life Sciences: Evolution Parallels Thermodynamics, Cellulose Hydrolysis Thermodynamics, And Ordered And Disordered Vacancies Thermodynamics, Marko Popovic

All Theses and Dissertations

Entropy, first introduced in thermodynamics, is used in a wide range of fields. Chapter 1 discusses some important theoretical and practical aspects of entropy: what is entropy, is it subjective or objective, and how to properly apply it to living organisms. Chapter 2 presents applications of entropy to evolution. Chapter 3 shows how cellulosic biofuel production can be improved. Chapter 4 shows how lattice vacancies influence the thermodynamic properties of materials. To determine the nature of thermodynamic entropy, Chapters 1 and 2 describe the roots, the conceptual history of entropy, as well as its path of development and application. From ...


Probabilistic Programming For Theory Of Mind For Autonomous Decision Making, Iris Rubi Seaman Jun 2018

Probabilistic Programming For Theory Of Mind For Autonomous Decision Making, Iris Rubi Seaman

All Theses and Dissertations

As autonomous agents (such as unmanned aerial vehicles, or UAVs) become more ubiquitous, they are being used for increasingly complex tasks. Eventually, they will have to reason about the mental state of other agents, including those agents' beliefs, desires and goals – so-called Theory of Mind – and make decisions based on that reasoning. We describe increasingly complex theory of mind models of a UAV pursuing an intruder, and show that (1) there is a natural Bayesian formulation to reasoning about the uncertainty inherent in our estimate of another agent's mental state, and that (2) probabilistic programming is a natural way ...


Network Specializations, Symmetries, And Spectral Properties, Dallas C. Smith Jun 2018

Network Specializations, Symmetries, And Spectral Properties, Dallas C. Smith

All Theses and Dissertations

In this dissertation, we introduce three techniques for network sciences. The first of these techniques is a series of new models for describing network growth. These models, called network specialization models, are built with the idea that networks grow by specializing the function of subnetworks. Using these models we create theoretical networks which exhibit well-known properties of real networks. We also demonstrate how the spectral properties are preserved as the models grow. The second technique we describe is a method for decomposing networks that contain automorphisms in a way that preserves the spectrum of the original graph. This method for ...


Evaluating The Usability Of Two-Factor Authentication, Kendall Ray Reese Jun 2018

Evaluating The Usability Of Two-Factor Authentication, Kendall Ray Reese

All Theses and Dissertations

Passwords are the dominant form of authentication on the web today. However,many users choose weak passwords and reuse the same password on multiple sites, thus increasing their vulnerability to having their credentials leaked or stolen. Two-factor authentication strengthens existing password authentication schemes against impersonation attacks and makes it more difficult for attackers to reuse stolen credentials on other websites. Despite the added security benefits of two-factor authentication, there are still many open questions about its usability. Many two-factor authentication systems in widespread usage today have not yet been subjected to adequate usability testing. Previous comparative studies have demonstrated significant ...


Adaptive Fluid Simulation Using A Linear Octree Structure, Sean A. Flynn May 2018

Adaptive Fluid Simulation Using A Linear Octree Structure, Sean A. Flynn

All Theses and Dissertations

An Eulerian approach to fluid flow provides an efficient, stable paradigm for realistic fluid simulation. However, its traditional reliance on a fixed-resolution grid is not ideal for simulations that simultaneously exhibit both large and small-scale fluid phenomena. Octree-based fluid simulation approaches have provided the needed adaptivity, but the inherent weakness of a pointer-based tree structure has limited their effectiveness. We present a linear octree structure that provides a significant runtime speedup using these octree-based simulation algorithms. As memory prices continue to decline, we leverage additional memory when compared to traditional octree structures to provide this improvement. In addition to reducing ...


Signal Structure For A Class Of Nonlinear Dynamic Systems, Meilan Jin May 2018

Signal Structure For A Class Of Nonlinear Dynamic Systems, Meilan Jin

All Theses and Dissertations

The signal structure is a partial structure representation for dynamic systems. It characterizes the causal relationship between manifest variables and is depicted in a weighted graph, where the weights are dynamic operators. Earlier work has defined signal structure for linear time-invariant systems through dynamical structure function. This thesis focuses on the search for the signal structure of nonlinear systems and proves that the signal structure reduces to the linear definition when the systems are linear. Specifically, this work: (1) Defines the complete computational structure for nonlinear systems. (2) Provides a process to find the complete computational structure given a state ...


A New Family Of Topological Invariants, Nicholas Guy Larsen Apr 2018

A New Family Of Topological Invariants, Nicholas Guy Larsen

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We define an extension of the nth homotopy group which can distinguish a larger class of spaces. (E.g., a converging sequence of disjoint circles and the disjoint union of countably many circles, which have isomorphic fundamental groups, regardless of choice of basepoint.) We do this by introducing a generalization of homotopies, called component-homotopies, and defining the nth extended homotopy group to be the set of component-homotopy classes of maps from compact subsets of (0,1)n into a space, with a concatenation operation. We also introduce a method of tree-adjoinment for "connecting" disconnected metric spaces and show how this ...


Thin Film Carbon Nanofuses For Permanent Data Storage, Kevin Robert Laughlin Apr 2018

Thin Film Carbon Nanofuses For Permanent Data Storage, Kevin Robert Laughlin

All Theses and Dissertations

We have fabricated nanofuses from thin-film, arc-evaporation carbon for use in permanent data storage. Thin film carbon fuses have fewer fabrication barriers and retain the required resistivity and structural stability to work as a data storage medium. Carbon thin films were characterized for their electrical, microstructural, and chemical bonding properties. Annealing the thin-film carbon in an argon environment at 400°C reduced the resistivity from about 4*10-2 Ω cm as deposited down to about 5*10-4 Ω cm, allowing a lower blowing voltage. Nanofuses with widths ranging from 200 nm down to 60 nm were fabricated and ...


Subtraction Games: Range And Strict Periodicity, Bryce Emerson Blackham Apr 2018

Subtraction Games: Range And Strict Periodicity, Bryce Emerson Blackham

All Theses and Dissertations

In this paper I introduce some background for subtraction games and explore the Sprague-Grundy functions defined on them. I exhibit some subtraction games where the functions are guaranteed to be strictly periodic. I also exhibit a class of subtraction games which have bounded range, and show there are uncountably many of these.


A Geophysical And Geological Analysis Of A Regressive-Phase Lake Bonneville Deposit, Pilot Valley, Nv, Katelynn Marie Smith Apr 2018

A Geophysical And Geological Analysis Of A Regressive-Phase Lake Bonneville Deposit, Pilot Valley, Nv, Katelynn Marie Smith

All Theses and Dissertations

Pilot Valley, located in the eastern Basin and Range, north of Wendover, UT, contains numerous shorelines and depositional remnants of late Pleistocene Lake Bonneville. These remnants present classic ground penetrating radar (GPR) targets due to their coherent stratification, low clay, low salinity, and low moisture content. Three-dimensional (3D) GPR imaging can resolve fine-scale stratigraphy of these deposits down to a few centimeters. While lake levels fluctuated due to flooding events, climatic changes were the dominant factor in controlling lake levels. In Pilot Valley, the paleowind entered from the northwest, with storms coming from the south, and circulated clockwise around the ...


A Geomorphological Study Of Yardangs In China, The Altiplano/Puna Of Argentina, And Iran As Analogs For Yardangs On Titan, Dustin Shawn Northrup Apr 2018

A Geomorphological Study Of Yardangs In China, The Altiplano/Puna Of Argentina, And Iran As Analogs For Yardangs On Titan, Dustin Shawn Northrup

All Theses and Dissertations

Collections of straight, RADAR-bright, linear features, or BLFs, on Saturn's moon Titan are revealed in Cassini SAR (Synthetic Aperture RADAR) images. Most are widely distributed across the northern midlatitudes SAR on SAR swaths T18, T23, T30, T64, and T83 and in swath T56 in the southern midlatitudes. To understand the origin of these features, we compare them with terrestrial yardangs in Dunhuang, China, the Altiplano/Puna of Argentina, and the Lut Desert of Iran and with a similar morphological landform, linear dunes in the Namib Sand Sea, Namibia and on Titan. We apply a statistical classification model developed through ...


A Large-Scale Analysis Of How Openssl Is Used In Open-Source Software, Scott Jared Heidbrink Mar 2018

A Large-Scale Analysis Of How Openssl Is Used In Open-Source Software, Scott Jared Heidbrink

All Theses and Dissertations

As vulnerabilities become more common the security of applications are coming under increased scrutiny. In regards to Internet security, recent work discovers that many vulnerabilities are caused by TLS library misuse. This misuse is attributed to large and confusing APIs and developer misunderstanding of security generally. Due to these problems there is a desire for simplified TLS libraries and security handling. However, as of yet there is no analysis of how the existing APIs are used, beyond how incorrect usage motivates the need to replace them. We provide an analysis of contemporary usage of OpenSSL across 410 popular secure applications ...


Paleo-Environmental Interpretations And Weathering Effects Of The Mowry Shale From Geochemical Analysis Of Outcrop Samples In The Western Margin Of The Wind River Basin Near Lander, Wyoming, Trevor Robinson Tuttle Mar 2018

Paleo-Environmental Interpretations And Weathering Effects Of The Mowry Shale From Geochemical Analysis Of Outcrop Samples In The Western Margin Of The Wind River Basin Near Lander, Wyoming, Trevor Robinson Tuttle

All Theses and Dissertations

The Cretaceous Mowry Shale is an organic-rich, siliceous marine shale, and as such is a known source rock in the Western United States. Studies have documented that total organic carbon (TOC) in the Wind River Basin, Wyoming increases to the southeast. These studies cover large areas with limited sample sets. In this study, over 250 samples were collected near Lander, Wyoming to address spatial heterogeneity of TOC within the Mowry Shale at a much finer scale than previously examined. Samples were collected along five vertical sections at three localities, and following correlation of the vertical sections, which was strongly aided ...


Discovery Of Possible Paleotsunami Deposits In Pangandaran And Adipala, Java, Indonesia Using Grain Size, Xrd, And 14C Analyses, Kevin L. Stuart Mar 2018

Discovery Of Possible Paleotsunami Deposits In Pangandaran And Adipala, Java, Indonesia Using Grain Size, Xrd, And 14C Analyses, Kevin L. Stuart

All Theses and Dissertations

Grain size, 14C age, and X-ray diffraction (XRD) analyses of sediments indicate possible tsunami deposits on the southern coast of Java near Pangandaran and Adipala. Previous studies that have described known recent and paleotsunami deposits were used for comparison. Fining-upward grain size trends, interbedded sand and mud, sediment composition, and trends in heavy mineral abundances are among the characteristics used for tsunami deposit identification. At Batu Kalde, an archaeological site south of Pangandaran, a layer of aragonitic sand with marine fossils was found atop a layer of archaeological fragments at an elevation of ~2-5 m. It is likely this ...


Evaporated Aluminum Fluoride As A Barrier Layer To Retard Oxidation Of Aluminum Mirrors, Margaret Miles Dec 2017

Evaporated Aluminum Fluoride As A Barrier Layer To Retard Oxidation Of Aluminum Mirrors, Margaret Miles

All Theses and Dissertations

The aluminum oxide growth rate for aluminum protected with 2.4 nm of aluminum fluoride has been determined. We show that a 2.4 nm aluminum fluoride layer does not prevent aluminum from oxidation but does significantly retard the oxide growth – decreasing the oxide layer thickness from 1 nm in less than an hour to 0.9 nm over 116 hours. Additionally, the optical constants for aluminum oxide growing under an aluminum fluoride barrier layer have been determined – showing an increase in absorption at high energies for Al2O3 forming at room temperature as compared to highly ordered ...


Recommender Systems For Family History Source Discovery, Derrick James Brinton Dec 2017

Recommender Systems For Family History Source Discovery, Derrick James Brinton

All Theses and Dissertations

As interest in family history research increases, greater numbers of amateurs are participating in genealogy. However, finding sources that provide useful information on individuals in genealogical research is often an overwhelming task, even for experts. Many tools assist genealogists in their work, including many computer-based systems. Prior to this work, recommender systems had not yet been applied to genealogy, though their ability to navigate patterns in large amounts of data holds great promise for the genealogical domain. We create the Family History Source Recommender System to mimic human behavior in locating sources of genealogical information. The recommender system is seeded ...


Quantitative Morphological Classification Of Planetary Craterforms Using Multivariate Methods Of Outline-Based Shape Analysis, Thomas Joseph Slezak Dec 2017

Quantitative Morphological Classification Of Planetary Craterforms Using Multivariate Methods Of Outline-Based Shape Analysis, Thomas Joseph Slezak

All Theses and Dissertations

Craters formed by impact and volcanic processes are among the most fundamental planetary landforms. This study examines the morphology of diverse craterforms on Io, the Moon, Mars, and Earth using quantitative, outline-based shape analysis and multivariate statistical methods to evaluate the differences between different types of. Ultimately, this should help establish relationships between the form and origin of craterforms. Developed in the field of geometric morphometrics by paleontological and biological sciences communities, these methods were used for the analysis of the shapes of crater outlines. The shapes of terrestrial ash-flow calderas, terrestrial basaltic shield calderas, martian calderas, Ionian paterae, and ...


A Coverage Metric To Aid In Testing Multi-Agent Systems, Jane Ostergar Linn Dec 2017

A Coverage Metric To Aid In Testing Multi-Agent Systems, Jane Ostergar Linn

All Theses and Dissertations

Models are frequently used to represent complex systems in order to test the systems before they are deployed. Some of the most complicated models are those that represent multi-agent systems (MAS), where there are multiple decision makers. Brahms is an agent-oriented language that models MAS. Three major qualities affect the behavior of these MAS models: workframes that change the state of the system, communication activities that coordinate information between agents, and the schedule of workframes. The primary method to test these models that exists is repeated simulation. Simulation is useful insofar as interesting test cases are used that enable the ...