Physical Sciences and Mathematics Commons^™

The State Of Man-In-The-Middle Tls Proxies: Prevalence And User Attitudes, Mark Thomas Oneill

Theses and Dissertations

We measure the prevalence and uses of Man-in-the-Middle TLS proxies using a Flash tool deployed with a Google AdWords campaign. We generate 15.2 million certificate tests across two large-scale measurement studies and find that 1 in 250 TLS connections are intercepted by proxies. The majority of these proxies appear to be benevolent, however we identify over 3,600 cases where eight malware products are using this technology nefariously. We also find thousands of instances of negligent, duplicitous, and suspicious behavior, some of which degrade security for users without their knowledge. Distinguishing these types of practices is challenging in practice, indicating a …

Energy Quantity Estimation In Radiated Acoustic Fields, Eric B. Whiting

Theses and Dissertations

Energy quantities, which are calculated from pressure and particle velocity, yield a great deal of information about acoustic fields. Errors in pressure or particle velocity estimation lead to bias errors the estimation of energy quantities. The bias errors arise from different probe configurations and processing methods. Two processing methods are examined: the traditional method and the recently developed Phase and Amplitude Gradient Estimation (PAGE) method. These two methods are compared to investigate how each estimates pressure and particle velocity and the subsequent bias errors in a plane wave, standing wave, and spherical spreading wave field. Analytical expressions are derived for …

Increasing The Computational Efficiency Of Combinatoric Searches, Wiley Spencer Morgan

Theses and Dissertations

A new algorithm for the enumeration of derivative superstructures of a crystal is presented. The algorithm will help increase the efficiency of computational material design methods such as cluster expansion by increasing the size and diversity of the types of systems that can be modeled. Modeling potential alloys requires the exploration of all possible configurations of atoms. Additionally, modeling the thermal properties of materials requires knowledge of the possible ways of displacing the atoms. One solution to finding all symmetrically unique configurations and displacements is to generate the complete list of possible configurations and remove those that are symmetrically equivalent. …

Natural And Anthropogenic Sources Of Arsenic And Nitrate In A Semi-Arid Alluvial Basin; Goshen Valley, Utah, Brian John Selck

Theses and Dissertations

Arsenic (As) and nitrate (NO₃) are common contaminants in groundwater that are introduced through a variety of natural and anthropogenic sources. In this study we investigated the sources and distribution of As and NO₃ in Goshen Valley, Utah, USA. Goshen Valley is a semi-arid alluvial basin that is impacted by geothermal waters, agriculture, urban development, and legacy mining. In this study we sampled surface water, springs, and wells to analyze concentrations of major ions, trace elements (As, B, Ba, Ca, Fe, K, Li, Mg, Mn, Mo, Pb, Si, Sr, Zn), and stable isotopes in water (δ^{18 …}

Creating And Automatically Grading Annotated Questions, Alicia Crowder Wood

Theses and Dissertations

We have created a question type that allows teachers to easily create questions, helps provide an intuitive user experience for students to take questions, and reduces the time it currently takes teachers to grade and provide feedback to students. This question type, or an "annotated" question, will allow teachers to test students' knowledge in a particular subject area by having students "annotate" or mark text and video sources to answer questions. Through user testing we determined that overall the interface and the implemented system decrease the time it would take a teacher to grade annotated quiz questions. However, there are …

Performance Of Phase And Amplitude Gradient Estimator Method For Calculating Energy Quantities In A Plane-Wave Tube Environment, Daxton A. Hawks

Student Works

Acoustic intensity, energy densities, and impedance are useful quantities when considering sound fields. Calculating these energy quantities relies on measurements of acoustic pressure and particle velocity. Pressure and particle velocity can be directly measured, but direct measurements of particle velocity are difficult to make, and are normally inaccurate. A more common and effective way to find particle velocity is to estimate it using pressure measurements from two closely-spaced microphones. The traditional way of estimating particle velocity is severely limited by frequency. The PAGE method, developed at Brigham Young University, extends the frequency bandwidth at which accurate estimations can be made. …

Daxton Hawks Reu Prospectus, Daxton A. Hawks

Student Works

The purpose of my research is to investigate the ability of the PAGE method to improve the frequency bandwidth of calculations of energy-based quantities from multiple pressure microphones. I will accomplish this by investigating sound waves in both plane-wave and standing-wave environments. I will compare the PAGE method calculations for Ia, Ir, Ep, Ek, and Z to those of traditional and analytical expressions, based on careful ambient condition monitoring. Quantifying the bandwidth extension of the PAGE method for these energy-based quantities will lay a foundation for further application.

Preventing Oxidation Of Aluminum Films With Cadmium Of Zinc Barriers, Spencer B. Perry

Student Works

The planned Large UV/Optical/Near-infrared Telescope (LUVOIR) is expected to launch sometime in the 2030s if NASA surveys recommend LUVOIR over several other projects in early developmental stages [1]. As the project title suggests, the proposed telescope would include large mirrors (between 8 and 16 meters) as part of the orbiting reflector telescope. My research focused on the preparation of aluminum mirrors with zinc or cadmium barrier layers that were designed to prevent oxidation of the aluminum.

Opportunities To Investigate Novel Stable P-Type Zno: Making Progress With The Asymmetric Dopant Problem, Davild Allred

BYU Research Development Office Research Networking Conference

For over 60 years p-type Wide-bandgap semiconductors have been a problem. ZnO has been described as a very desirable semiconductor materials.

How to make stable forms of moderate to heavily p-type semiconductors, For example, for zinc-oxide this elusive goal has been driven by the material’s desirable electronic, thermal, and mechanical properties.

The traditional approach seems unlikely to succeed due to compound stability and vapor pressure constraints on diffusional processes. Diffusion couples cannot be used to create long-term stable p-type zinc oxides.

Nanomagnetism, Karine Chesnel

BYU Research Development Office Research Networking Conference

Studying the magnetic domain pattern morphology and its dependence dependence with previously applied field

The Phraseworthy App, Dallin D. Oaks

BYU Research Development Office Research Networking Conference

Brainstorming software that provides ideas about potential word plays for headlines, slogans, product names, titles, and more.

Probabilistic Programming For Perceptually Driven Autonomous Agents, David Wingate

BYU Research Development Office Research Networking Conference

This research will bridge the gap between cognitive science models and machine learning techniques, resulting in autonomous agents that are not only powerful and adaptive but also understandable and safe to deploy.

The development of a dedicated probabilistic programming language will empower researchers and developers to create sophisticated autonomous systems with greater ease and confidence.

From Qualitative To Quantitative: Supporting Robot Understanding In Human-Interactive Path Planning, Daqing Yi

Theses and Dissertations

Improvements in robot autonomy are changing human-robot interaction from low-level manipulation to high-level task-based collaboration. When a robot can independently and autonomously executes tasks, a human in a human-robot team acts as a collaborator or task supervisor instead of a tele-operator. When applying this to planning paths for a robot's motion, it is very important that the supervisor's qualitative intent is translated into aquantitative model so that the robot can produce a desirable consequence. In robotic path planning, algorithms can transform a human's qualitative requirement into a robot's quantitative model so that the robot behavior satisfies the human's intent. In …

Emission From Black Holes And Supernovae In The Early Universe, Brandon Kerry Wiggins

Theses and Dissertations

To constrain the era when the first galaxies and stars appeared upcoming instruments will rely on the brightest events in the universe: supernovae and brilliant emission from massive black holes. In this dissertation, we investigate the observability of certain types of supernovae of the very first stars (Population III stars) and find that while these events are sufficiently luminous to be observed with deep-sky instruments such as the James Webb Space Telescope (JWST), they may not observe these particular types of events in their lifetimes. We next explore the origins of massive black holes and introduce the direct collapse hypothesis …

Steady State Configurations Of Cells Connected By Cadherin Sites, Jared Adam Mcbride

Theses and Dissertations

Many cells employ cadherin complexes (c-sites) on the cell membrane to attach to neighboring cells, as well as integrin complexes (i-sites) to attach to a substrate in order to accomplish cell migration. This paper analyzes a model for the motion of a group of cells connected by c-sites. We begin with two cells connected by a single c-site and analyze the resultant motion of the system. We find that the system is irrotational. We present a result for reducing the number of c-sites in a system with c-sites between pairs of cells. This greatly simplifies the general system, and provides …

Gas Phase Structure Characterization Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Anupriya Anupriya

Theses and Dissertations

This dissertation investigates Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) based techniques to study the impact of molecular structure on conformation and binding energetics. A novel method to determine collison cross sectional areas using FTICR (CRAFTI), initially developed by the Dearden lab, was applied to study the conformations of molecular systems with unique structural attributes in an attempt to explore the molecular range of CRAFTI. The systems chosen for CRAFTI studies include crown-ether alkylammonium complexes and biogenic amino acids. The results were found to be consistent with expected behavior, and strongly correlated with experimental measurements made using ion mobility …

The Quest To Secure Email: A Usability Analysis Of Key Management Alternatives, Jeffrey Thomas Andersen

Theses and Dissertations

The current state of email security is lacking, and the need for end-to-end encryption of email is clear. Recent research has begun to make progress towards usable, secure email for the masses (i.e., novice users without IT support). In this paper, we evaluate the usability implications of three different key management approaches: PGP, IBE, and passwords. Our work is the first formal A/B evaluation of the usability of different key management schemes, and the largest formal evaluation of secure email ever performed. Our results reveal interesting inherent usability trade-offs for each approach to secure email. Furthermore, our research results in …

Computational Studies Of Alkane C-H Functionalization By Main-Group Metals, Samantha Jane Gustafson

Theses and Dissertations

The most efficient homogeneous catalysts for hydroxylation of light alkanes utilize transition metals in superacid solvent and operate by tandem electrophilic C-H activation/metal-alkyl (M-R) functionalization. An emerging alternative strategy to transition metals is the use of high-oxidation state main-group metals (e.g. TlIII, PbIV, IIII) that hydroxylate light alkanes. This dissertation reports density-functional theory calculations that reveal the mechanisms, reactivity, and selectivity of TlIII promoted alkane C-H functionalization in trifluoroacetic acid and TlIII-dialkyl functionalization in water. Calculations reveal that TlIII oxidizes alkanes via a closed-shell C-H activation and M-R functionalization mechanism that is similar to transition-metal C-H functionalization mechanisms. Comparison of …

Computational Studies On Mechanisms And Reactivity Of Mercury And Cobalt Organometallic Reactions, Jack Terrell Fuller

Theses and Dissertations

Density Functional Theory (DFT) is a powerful tool for treating large organometallic structures efficiently and accurately. DFT calculations on the Hg-catalyzed oxidation of methane to methyl bisulfate in sulfuric acid suggest the lowest energy pathway involves a closed-shell electrophilic C–H activation mechanism coupled with metal alkyl reductive functionalization and oxidation by SO3. Comparison to Tl, Zn, and Cd suggests that Hg is unique in its ability to catalyze this set of reaction steps. Comparison to K2S2O8 highlights the selectivity of this C–H activation reaction as opposed to radical conditions. In contrast, DFT calculations indicate that CoIII(TFA)3 oxidizes methane through a …

Studies Toward Yaku'amide A And Synthesis And Applications Of Bulky Α,Β-Dehydroamino Acids, Jintao Jiang

Theses and Dissertations

Yaku'amide A shows a unique inhibitory profile against a series of 39 human cancer cell lines (JFCR39). In our efforts to synthesize yaku'amide A, we have optimized our regioselective base-free aminohydroxylation method with a series of nitrogen sources, developed a chiral reagent-mediated aminohydroxylation strategy and chemoselective deprotections of the resulting aminohydroxylation product, and explored a stereospecific E2 dehydration and O-N acyl transfer sequence. In addition, we have prepared the right-hand tetrapeptide and the NTA subunit. For our bulky α,β-dehydroamino acids project, we have developed strategies to incorporate α,β-dehydroamino acids such as ΔVal and ΔEnv into small synthetic peptides via Solid …

Synthesis And Biological Evaluation Of Small Molecule Inhibitors Of Bmpr1b, Paulo Andre Machicao Tello

Theses and Dissertations

Methods for preparing an array of potential small molecule inhibitors of Bone Morphogenetic Protein Receptor 1b (BMPR1b) are described. Target molecules were prepared from two general classes: (1) N9-aryl-N6-ureidoadenines, and (2) dicarbamyl iodoacetamides. Recent data from the Peterson lab indicated that both classes might bind to BMPR1b and thus inhibit this key receptor. Docking studies performed using Sureflex Dock suggested the N9-aryl-N6-ureidoadenines would bind to the active site of BMPR1b. In addition antiproliferative activities of dicarbamyl iodoacetamides previously synthesized in the Peterson lab pointed to this moiety as an attractive target for structure activity relationship (SAR) development. Compounds were prepared …

Usable, Secure Content-Based Encryption On The Web, Scott Ruoti

Theses and Dissertations

Users share private information on the web through a variety of applications, such as email, instant messaging, social media, and document sharing. Unfortunately, recent revelations have shown that not only is users' data at risk from hackers and malicious insiders, but also from government surveillance. This state of affairs motivates the need for users to be able to encrypt their online data.In this dissertation, we explore how to help users encrypt their online data, with a special focus on securing email. First, we explore the design principles that are necessary to create usable, secure email. As part of this exploration, …

Theoretical And Experimental Investigation Of A Quadspectral Nonlinearity Indicator, Kyle Glen Miller

Theses and Dissertations

Understanding the impact of jet noise and other high-amplitude sound sources can be improved by quantifying the nonlinearity in a signal with a single-microphone measurement. An ensemble-averaged, frequency-domain version of the generalized Burgers equation has been used to derive a quantitative expression for the change in spectral levels (in decibels) over distance due to geometric spreading, thermoviscous absorption, and nonlinearity, respectively. The nonlinearity indicator, called νN , is based on the quadspectral Morfey-Howell indicator, which has been used in the past to characterize nonlinearity in noise waveforms. Unlike the Morfey-Howell indicator, the νN indicator has direct physical significance, giving a …

Modeling Of Acoustic Resonators And Resonator Systems For Use In Passive Noise Control, Matthew Franklin Calton

Theses and Dissertations

Acoustic resonators, such as the Helmholtz and quarter-wave resonator, can be used to attenuate unwanted noise in an enclosed space. Classical formulations can be used to approximate resonator performance for a given resonator configuration, but may lack sufficient accuracy for some applications. This research aims to improve the analytical characterization of resonators to provide better correlation to experimental results. Using higher-order approximations and proper end corrections, more accuracy can be obtained in calculating the impedance and resonance frequency of a single resonator, which will then carry over into the overall configuration of the model. The impedance of a system of …

Finding The First Stars, Eli D. Mcarthur

Student Works

Minor perturbations resulting from a brief period of inflation at the time of the universe's birth seeded the growth of all structure in the universe. Using Enzo, a research code optimized for running cosmological simulations, we simulate the formation of the universe. We take into account the most current cosmological parameters and plot star formation rates of the universe for halos of varying mass from the beginning of time until today. By simulating star formation of the early universe, we verify that initially minuscule dark matter pockets resulting from inflationary perturbations attract more and more matter as the universe expands. …

A Distributed Control Algorithm For Small Swarms In Cordon And Patrol, C Kristopher Alder

Student Works

Distributed teams of air and ground robots have the potential to be very useful in a variety of application domains, and much work is being done to design distributed algorithms that produce useful behaviors. This thesis presents a set of distributed algorithms that operate under minimal human input for patrol and cordon tasks. The algorithms allow the team to surround and travel between objects of interest. Empirical analyses indicate that the surrounding behaviors are robust to variations on the shape of the object of interest, communication loss, and robot failures.

Analyses Of Mrna Cleavage By Rele And The Role Of Trna Methyltransferase Trmd Using Bacterial Ribosome Profiling, Jae Yeon Hwang

Theses and Dissertations

Protein synthesis is a fundamental and ultimate process in living cells. Cells possess sophisticated machineries and continuously carry out complex processes. Monitoring protein synthesis in living cells not only inform us about the mechanism of translation but also deepen our insights about all aspects of life. Understanding the structure and mechanism of the ribosome and its associated factors helped us enlarge our knowledge on protein synthesis. Recently, with the dramatic advances of high-throughput sequencing and bioinformatics, a new technique called ribosome profiling emerged. By retrieving mRNA fragments protected by translating ribosomes, ribosome profiling reveals global ribosome occupancy along mRNAs in …

Sedimentology And Stratigraphy Of The Middle Jurassic Preuss Sandstonein Northern Utah And Eastern Idaho, Preston Scott Cook

Theses and Dissertations

The purpose of this study is to analyze the sedimentology and stratigraphy of the Middle Jurassic Preuss Sandstone and re-evaluate past sedimentological interpretations. The Preuss is located in northern Utah, western Wyoming and eastern Idaho and is stratigraphically equivalent to the Entrada Sandstone, which is Callovian in age (Dossett et al., 2014). This study is the first attempt at 1) a sequence stratigraphic framework, 2) a petroleum system analysis and 3) an extraterrestrial analog study for the Preuss. This study frames the Preuss within three broad facies groups: marine, coastal and terrestrial. The marine group includes the open marine and …

Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer

Student Works

Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were …

Geochemistry Of The Fluorine- And Beryllium-Rich Spor Mountain Rhyolite, Western Utah, Shane Robert Dailey

Theses and Dissertations

The Miocene rhyolites of the Spor Mountain Formation hosts the world's largest beryllium deposit which produced 85% of the world's beryllium in 2010. The fresh lava is extremely enriched in Be (up to 75 ppm in matrix glass). We have examined the rhyolite to understand the Be enrichment. The Spor Mountain rhyolite contains ~40% quartz, ~40% sanidine, ~10% biotite, and ~10% plagioclase, along with accessory fluorite, columbite, euxenite, fergusonite, monazite, thorite, and zircon. Two types of rhyolite erupted within the Spor Mountain Formation, a less evolved magma (1150 ppm Rb, 42 ppm Be, 0.68 wt% F in matrix glass) and …