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Articles 481 - 510 of 2906

Full-Text Articles in Physical Sciences and Mathematics

Impacts Of Glacial Meltwater On Geochemistry And Discharge Of Alpine Proglacial Streams In The Wind River Range, Wyoming, Usa, Natalie Shepherd Barkdull Jul 2019

Impacts Of Glacial Meltwater On Geochemistry And Discharge Of Alpine Proglacial Streams In The Wind River Range, Wyoming, Usa, Natalie Shepherd Barkdull

Theses and Dissertations

Shrinking alpine glaciers alter the geochemistry of sensitive mountain streams by exposing reactive freshly-weathered bedrock and releasing decades of atmospherically-deposited trace elements from glacier ice. Changes in the timing and quantity of glacial melt also affect discharge and temperature of alpine streams. To investigate the effects of glacier ice melt on the geochemistry and hydrology of proglacial streams in the arid Intermountain West, we sampled supraglacial meltwaters and proglacial streams in the Dinwoody Creek watershed in the Wind River Range, Wyoming during late summer 2015, when the contributions of glacier meltwater were highest. Supraglacial meltwater was enriched in 8 trace …

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Developing Understanding Of The Chain Rule, Implicit Differentiation, And Related Rates: Towards A Hypothetical Learning Trajectory Rooted In Nested Multivariation, Haley Paige Jeppson Jul 2019

Developing Understanding Of The Chain Rule, Implicit Differentiation, And Related Rates: Towards A Hypothetical Learning Trajectory Rooted In Nested Multivariation, Haley Paige Jeppson

Theses and Dissertations

There is an overemphasis on procedures and manipulation of symbols in calculus and not enough emphasis on conceptual understanding of the subject. Specifically, students struggle to understand and correctly apply concepts in calculus such as the chain rule, implicit differentiation, and related rates. Students can learn mathematics more deeply when they make connections between different mathematical ideas. I have hypothesized that students can make powerful connections between the chain rule, implicit differentiation, and related rates through the mathematical concept of nested multivariation. Based on this hypothesis, I created a hypothetical learning trajectory (HLT) rooted in nested multivariation for students to …

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Sequence Biostratigraphy Of Carboniferous-Permian Boundary Strata In Western Utah: Deciphering Eustatic And Tectonic Controls On Sedimentation In The Antler-Sonoma Distal Foreland Basin, Joshua Kerst Meibos Jul 2019

Sequence Biostratigraphy Of Carboniferous-Permian Boundary Strata In Western Utah: Deciphering Eustatic And Tectonic Controls On Sedimentation In The Antler-Sonoma Distal Foreland Basin, Joshua Kerst Meibos

Theses and Dissertations

The stratal architecture of the upper Ely Limestone and Mormon Gap Formation (Pennsylvanian-early Permian) in western Utah reflects the interaction of icehouse sea-level change and tectonic activity in the distal Antler-Sonoma foreland basin. Eighteen physically and biostratigraphically corelated stratigraphic sections provide a database for tracing Permo-Carboniferous boundary strata over a north-south distance of 60 km. These formations comprise 14 unconformity-bounded depositional sequence: three in the upper Ely (UE1-UE3) and 11 in the Mormon Gap Formation (MG1-MG11). Conodont and fusulinid faunas provide precise biostratigraphic information for a number of parasequences in the upper Ely and Mormon Gap formations. This paleontological information …

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A Shared-Memory Coupled Architecture To Leverage Big Data Frameworks In Prototyping And In-Situ Analytics For Data Intensive Scientific Workflows, Alexander Michael Lemon Jul 2019

A Shared-Memory Coupled Architecture To Leverage Big Data Frameworks In Prototyping And In-Situ Analytics For Data Intensive Scientific Workflows, Alexander Michael Lemon

Theses and Dissertations

There is a pressing need for creative new data analysis methods whichcan sift through scientific simulation data and produce meaningfulresults. The types of analyses and the amount of data handled by currentmethods are still quite restricted, and new methods could providescientists with a large productivity boost. New methods could be simpleto develop in big data processing systems such as Apache Spark, which isdesigned to process many input files in parallel while treating themlogically as one large dataset. This distributed model, combined withthe large number of analysis libraries created for the platform, makesSpark ideal for processing simulation output.Unfortunately, the filesystem becomes …

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Nature And Origin Of Fissure Ore At The Porphyry-Epithermal Transition Zone Of The Bingham Canyon Porphyry Cu-Au-Mo Deposit, Utah, David Harris Tomlinson Jul 2019

Nature And Origin Of Fissure Ore At The Porphyry-Epithermal Transition Zone Of The Bingham Canyon Porphyry Cu-Au-Mo Deposit, Utah, David Harris Tomlinson

Theses and Dissertations

Late-stage fissure-filling ore at the world class Bingham Canyon, Utah, porphyry copper deposit has long been recognized, but poorly studied. Physical and chemical characterization of the Pb-Zn-Cu-Ag-Au mineralized fissures in the porphyry-epithermal transition zone provides insight into the origin, timing, and controls of ore deposition. These sheared sulfide-rich fissures are dominated by pyrite and multiple generations of quartz, with lesser amounts of other sulfides and gangue minerals. Au (0.27 to 4.61 ppm) provides the most value to the ore in the transition zone. Host rocks include Eocene monzonite and Paleozoic limestone and quartzite"”all of which can contain economic ore bodies. …

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Cannibalization Processes In Hotspot Rhyolites As Deduced From The Kimberly Rhyolite, Central Snake River Plain, Idaho, Usa, Danielle Jeannette Spencer Jul 2019

Cannibalization Processes In Hotspot Rhyolites As Deduced From The Kimberly Rhyolite, Central Snake River Plain, Idaho, Usa, Danielle Jeannette Spencer

Theses and Dissertations

The 7.7 Ma Kimberly Member of the Cassia Formation is part of a succession of A-type rhyolites associated with the Yellowstone hotspot track. It was sampled by the Kimberly core that was drilled on the Snake River Plain as part of Project HOTSPOT (Shervais, et al., 2013). The Kimberly Member is a 170 m thick high-silica rhyolite lava flow containing quartz, plagioclase, anorthoclase, sanidine, augite, pigeonite, magnetite, ilmenite, zircon, and apatite. δ 18O of zircon ranges from 0 to 4.9‰ (Colón et al., 2018), typical low values for the Snake River Plain. Quartz is intensely embayed. Exsolved and resorbed pigeonite …

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Dna Capture Via Magnetic Beads In A Microfluidic Platformfor Rapid Detection Of Antibiotic Resistance Genes, David Hyrum Harris Jul 2019

Dna Capture Via Magnetic Beads In A Microfluidic Platformfor Rapid Detection Of Antibiotic Resistance Genes, David Hyrum Harris

Theses and Dissertations

Antibiotic resistant infections are a growing health care concern, with many cases reported annually. Infections can cause irreversible bodily damage or death if they are not diagnosed in a timely matter. To rapidly diagnose antibiotic resistance in infections, it is important to be able to capture and isolate the DNA coding for the resistance genes. This is challenging because bacteria are present in blood in minute concentrations. To enrich the DNA to detectable levels, I modified magnetic microbeads with ssDNA sequences complementary to the target DNA to capture the DNA via hybridization. I compared DNA capture efficiency in three different …

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Fluvial Architecture And Reservoir Modeling Along The Strike Direction Of The Trail Member Of The Ericson Sandstone, Mesaverde Group In Southwest Wyoming, April Anahi Trevino Jul 2019

Fluvial Architecture And Reservoir Modeling Along The Strike Direction Of The Trail Member Of The Ericson Sandstone, Mesaverde Group In Southwest Wyoming, April Anahi Trevino

Theses and Dissertations

The Trail Member of the upper Cretaceous Ericson Sandstone, part of the Mesaverde Group, is exposed along hundreds of square kilometers through Wyoming along the flanks of several Laramide structural uplifts. This presents a unique opportunity to study the detailed architecture based on bed-scale heterogeneity and better assess the reservoir potential of these strata in outcrop exposure on a regional-scale, and to then relate these observations to producing fields nearby. The fluvial-dominated Trail Member formed as sediments traveled from the active Sevier thrust belt to the Cretaceous Interior Seaway, forming a basinward progradational clastic wedge along a relatively high gradient. …

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3d Printed Microfluidic Devices For Bioanalysis, Michael J. Beauchamp Jul 2019

3d Printed Microfluidic Devices For Bioanalysis, Michael J. Beauchamp

Theses and Dissertations

This work presents the development of 3D printed microfluidic devices and their application to microchip analysis. Initial work was focused on the development of the printer resin as well as the development of the general rules for resolution that can be achieved with stereolithographic 3D printing. The next stage of this work involved the characterization of the printer with a variety of interior and exterior resolution features. I found that the minimum positive and negative feature sizes were about 20 μm in either case. Additionally, micropillar arrays were printed with pillar diameters as small as 16 μm. To demonstrate one …

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Measuring Influence On Linear Dynamical Networks, Jaekob Chenina Jul 2019

Measuring Influence On Linear Dynamical Networks, Jaekob Chenina

Theses and Dissertations

Influence has been studied across many different domains including sociology, statistics, marketing, network theory, psychology, social media, politics, and web search. In each of these domains, being able to measure and rank various degrees of influence has useful applications. For example, measuring influence in web search allows internet users to discover useful content more quickly. However, many of these algorithms measure influence across networks and graphs that are mathematically static. This project explores influence measurement within the context of linear time invariant (LTI) systems. While dynamical networks do have mathematical models for quantifying influence on a node-to-node basis, to the …

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Extensions Of The Power Group Enumeration Theorem, Shawn Jeffrey Green Jul 2019

Extensions Of The Power Group Enumeration Theorem, Shawn Jeffrey Green

Theses and Dissertations

The goal of this paper is to develop extensions of Polya enumeration methods which count orbits of functions. De Bruijn, Harary, and Palmer all worked on this problem and created generalizations which involve permuting the codomain and domain of functions simultaneously. We cover their results and specifically extend them to the case where the group of permutations need not be a direct product of groups. In this situation, we develop a way of breaking the orbits into subclasses based on a characteristic of the functions involved. Additionally, we develop a formula for the number of orbits made up of bijective …

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Sequential Survival Analysis With Deep Learning, Seth William Glazier Jul 2019

Sequential Survival Analysis With Deep Learning, Seth William Glazier

Theses and Dissertations

Survival Analysis is the collection of statistical techniques used to model the time of occurrence, i.e. survival time, of an event of interest such as death, marriage, the lifespan of a consumer product or the onset of a disease. Traditional survival analysis methods rely on assumptions that make it difficult, if not impossible to learn complex non-linear relationships between the covariates and survival time that is inherent in many real world applications. We first demonstrate that a recurrent neural network (RNN) is better suited to model problems with non-linear dependencies in synthetic time-dependent and non-time-dependent experiments.

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Hyperparameters For Dense Neural Networks, Christopher James Hettinger Jul 2019

Hyperparameters For Dense Neural Networks, Christopher James Hettinger

Theses and Dissertations

Neural networks can perform an incredible array of complex tasks, but successfully training a network is difficult because it requires us to minimize a function about which we know very little. In practice, developing a good model requires both intuition and a lot of guess-and-check. In this dissertation, we study a type of fully-connected neural network that improves on standard rectifier networks while retaining their useful properties. We then examine this type of network and its loss function from a probabilistic perspective. This analysis leads to a new rule for parameter initialization and a new method for predicting effective learning …

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Multi-Stage Construction Of The Little Cottonwood Stock, Utah: Origin, Intrusion, Venting,Mineralization, And Mass Movement, Collin G. Jensen Jul 2019

Multi-Stage Construction Of The Little Cottonwood Stock, Utah: Origin, Intrusion, Venting,Mineralization, And Mass Movement, Collin G. Jensen

Theses and Dissertations

The Little Cottonwood stock in central Utah, USA, is a composite granitic pluton that hosts the White Pine porphyry Mo-W deposit towards its northeast margin. The deposit is centered on the smaller White Pine intrusion, and associated igneous units include the Red Pine porphyry, phreatomagmatic pebble dikes, and rhyolite dikes. Twelve new U-Pb zircon LA-ICP-MS ages, for samples from this deposit and in pebble dikes from the nearby East Traverse Mountains, give peak ages of about 30 Ma and 27 Ma for the Little Cottonwood stock and White Pine intrusion, respectively, which correlate well with ages from previous studies. Ages …

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Design And Synthesis Of Tlr2 And Tlr6 Heterodimer Ligands, A Triply Functionalized Α-Galcer Derivative For Identifying Proteins Involved In Glycolipid Trafficking, And The Disaccharide Of Staphylococcus Aureus Cp8 Towards A Self-Adjuvanting Vaccine, Sara Mayeth Mata Jul 2019

Design And Synthesis Of Tlr2 And Tlr6 Heterodimer Ligands, A Triply Functionalized Α-Galcer Derivative For Identifying Proteins Involved In Glycolipid Trafficking, And The Disaccharide Of Staphylococcus Aureus Cp8 Towards A Self-Adjuvanting Vaccine, Sara Mayeth Mata

Theses and Dissertations

Toll like receptors (TLRs) are found on B cells, macrophages, monocytes, and dendritic cells, and these cells belong to the innate immune system that recognizes antigens and induces multiple cell responses through the release of cytokines. TLR1, TLR2 and TLR6 function as heterodimers, either as TLR1/TLR2 or TLR2/TLR6 to recognize lipopeptides. TLR1/2 dimer activation releases inflammatory cytokines, while TLR2/TLR6 dimer activation releases immunomodulatory cytokines. Based on the size of the binding pocket between TLR2 and TLR6, it was hypothesized that lipopeptides, such as FSL1, could be simplified while keeping overall activity. FSL1 is a lipopeptide first isolated from Mycoplasma salivarum …

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Mentoring Astronomy Students Through Extensive Research (Master), Dr. Michael Joner Jun 2019

Mentoring Astronomy Students Through Extensive Research (Master), Dr. Michael Joner

Journal of Undergraduate Research

This Mentoring Environment Grant (MEG) proposed using the Brigham Young University West Mountain Observatory as a mentoring environment where students would experience what it is like to do research at a fully operational observatory by doing a wide variety of observations at regularly scheduled times over the course of several months during the spring and summer terms. The primary project in 2017 involved making nightly monitoring observations of the active Seyfert 1 galaxy Mrk 509 in support of a worldwide campaign involving more than a dozen ground–based and space–based observatories. In 2018, the primary monitoring campaign for extragalactic objects was …

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Understanding The Wind-Dominated Landforms Of Saturn’S Moon Titan Through Earth Analogues, Jani Radebaugh, Eric Christiansen, Shannon Tass Jun 2019

Understanding The Wind-Dominated Landforms Of Saturn’S Moon Titan Through Earth Analogues, Jani Radebaugh, Eric Christiansen, Shannon Tass

Journal of Undergraduate Research

The largest moon of Saturn, Titan, has a thick atmosphere of nitrogen and a pressure similar to that of Earth at the surface. There are winds, strong enough to have produced two wind-dominated landforms similar to those on Earth – vast fields of sand dunes and smaller collections of wind-carved ridges, or yardangs. We seek to understand the relationships between the observed landforms and the winds and surface materials required to form them, both on Earth and Titan. This study of the shapes of winddominated landforms, dunes and yardangs, will help answer key questions about the surface of Titan at …

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Applying Acoustic Beamforming In Sub-Arrays To Jet Engine Noise, David Van Komen, Kent Gee, Tracianne Nielson Jun 2019

Applying Acoustic Beamforming In Sub-Arrays To Jet Engine Noise, David Van Komen, Kent Gee, Tracianne Nielson

Journal of Undergraduate Research

In Jet engine noise is a large and complex area of research due to the intricacies of the variety of different mechanisms that produce noise traveling in different directions. The dominate noise source is called turbulent mixing noise (TMN) which is created by the interaction of the column of air mixing with the ambient air. Two types of TMN exist: large-scale TMN, the dominant noise source that travels away from the aircraft in the aft quadrant and fine-scale TMN that travels in all directions1. The second type of noise is known as broadband shock-associated noise (BBSAN), which is generated by …

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Computational Number Theory: Modular Forms, Paul Jenkins Jun 2019

Computational Number Theory: Modular Forms, Paul Jenkins

Journal of Undergraduate Research

In 2017 and 2018, the following students participated in the BYU Computational Number Theory research group under my direction and produced the following deliverables.

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Rational Design Of Multifunctional Enzyme-Like Catalysts For Assembly-Line Chemical Synthesis, David Michaelis Jun 2019

Rational Design Of Multifunctional Enzyme-Like Catalysts For Assembly-Line Chemical Synthesis, David Michaelis

Journal of Undergraduate Research

The main objectives of this proposal was to publish our preliminary findings in peptide catalysis and then submit applications for external funding. Both of these objectives were accomplished during the grant period. In the Fall of 2017, we published our first paper on the development of our new enzyme-like catalysts (ACS Catal. 2017, 7, 7704–7708). This publication should serve as a springboard for additional publications in the area (on which we are currently working) and help ensure external funding for this project. During 2017-2018, we submitted 3 grant applications to the NIH to help support this project. These submissions have …

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Magnetron Sputtering For The Production Of Stable P-Type Zno Thin Films, Colter Stewart, Dr. John Colton Jun 2019

Magnetron Sputtering For The Production Of Stable P-Type Zno Thin Films, Colter Stewart, Dr. John Colton

Journal of Undergraduate Research

The principal purpose of my research is to produce stable, long-lasting, reproducible p-type zinc oxide for experimental and commercial use. Semiconductor devices made with zinc oxide (ZnO) have the potential to be a cheaper alternative to those made with gallium nitride (GaN). In addition, ZnO devices could also have superior physical and optical properties [1]. Because of ZnO’s wide band gap and high radiation tolerance, it could potentially be used for UV lasers and LEDs, and thin-film transistors (TFTs) [2]. However, because of natural defects in the ZnO lattice, p-type ZnO has historically been difficult to produce [3]. Our group’s …

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Identifying Unknown Satellites, Nicholas Van Alfen, Joseph Moody Jun 2019

Identifying Unknown Satellites, Nicholas Van Alfen, Joseph Moody

Journal of Undergraduate Research

Satellites are used for a wide range of purposes and by a wide range of organizations from private companies to governments. Specifically, what was of interest to us and the Air Force Research Laboratory (AFRL) with whom we collaborated was the need to identify different satellites using telescopes and determine their purpose. Finding a cheap way to determine the design of a satellite and its use would be of great interest to national security in determining whether a previously unknown satellite is potentially harmful to our own country’s satellites in orbit around the Earth.

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The Development Of Individualized Anemia Treatments Using Point Of Care Diagnostics To Distinguish Anemia Caused By Infection Or Chronic Inflammation, Dr. Richard Watt Jun 2019

The Development Of Individualized Anemia Treatments Using Point Of Care Diagnostics To Distinguish Anemia Caused By Infection Or Chronic Inflammation, Dr. Richard Watt

Journal of Undergraduate Research

Background: Anemia that accompanies inflammation is associated with negative outcomes for patients. Early intervention to treat anemia is an important step in improving the quality of life for anemic patients. Our lab proposed to develop simple diagnostic tests using a Lateral Flow Immunoassays (LFIs) to measure the presence of a hormone called hepcidin because hepcidin is the master regulator of iron homeostasis in the body and elevated hepcidin levels lead to anemia.

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Microbes And Metals: Purifying The Water Of Lake Titicaca, Sara Ludlow, Dr. Gregory T. Carling Jun 2019

Microbes And Metals: Purifying The Water Of Lake Titicaca, Sara Ludlow, Dr. Gregory T. Carling

Journal of Undergraduate Research

Pollution of Lake Titicaca has become a major threat to the health and lifestyle of the Uru people who use the lake water for their daily needs. Cities along the coast dump untreated sewage directly into the lake introducing dangerous microbial levels of Escherichia coli. Runoff from nearby mines increases the risk of toxic levels of lead, arsenic, and other heavy metals. Previous members of the ongoing Global Engineering Outreach (GEO) program identified biosand filtration as a viable option for mitigating these risks. As such, they implemented single stage biosand filters in the community, but they were never able to …

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Random Polynomial Interpolation From Known Roots In The Multivariate Case, Catherine Sawyer, Tyler Jarvis Jun 2019

Random Polynomial Interpolation From Known Roots In The Multivariate Case, Catherine Sawyer, Tyler Jarvis

Journal of Undergraduate Research

The purpose of this project was to develop a method by which sets of multivariate polynomials with known roots could be rapidly generated. Generating such polynomials would be of great use in testing root finding algorithms, yet remains an open problem

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Inclusion Of Women In Computer Science, Naomi Johnson, Dr. Kevin Seppi Jun 2019

Inclusion Of Women In Computer Science, Naomi Johnson, Dr. Kevin Seppi

Journal of Undergraduate Research

Since the 1980’s, the percentage of computer science degrees awarded to women in the United States has fallen dramatically. There are growing numbers of men earning bachelor’s degrees in CS, and the numbers of women are increasing very slowly. For decades, researchers have been studying recruitment and retention of women and other minorities in CS, yet it is still not apparent what departments, professors, or students can do in order to get the numbers of women earning degrees in CS up again.

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Modeling Main Group Metal Alkane Functionalization Reactions In Highly Acidic Carboxylic And Sulfuric Acid Solvents, Lily H. Carlson, Daniel H. Ess Jun 2019

Modeling Main Group Metal Alkane Functionalization Reactions In Highly Acidic Carboxylic And Sulfuric Acid Solvents, Lily H. Carlson, Daniel H. Ess

Journal of Undergraduate Research

Our group is interested in identifying the unknown mechanisms of main-group C-H functionalization reactions. In the long term, our goal is to use computational chemistry tools to develop general principles on mechanisms, intermediates, reactivity, and selectivity for hydrocarbon C-H functionalization reactions by p-block main-group compounds as well as provide prediction of new catalysts and reactions. However, in providing these predictions, it remains unclear if different mechanistic pathways and intermediates will be predicted if examined in a complete solvent sphere (see Figure 1 for technical details). This is especially important for non-aqueous solvents such as carboxylic acids and sulfuric acid. To …

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Finding Planets Around Massive Stars, Elisabeth Frischnecht, Denise Stephens Jun 2019

Finding Planets Around Massive Stars, Elisabeth Frischnecht, Denise Stephens

Journal of Undergraduate Research

During the formation stages of a solar system, huge clouds of gas and dust contract into a disk around the growing star. These disks are the birthplace of planets, and are essential to our understanding of solar system formation. Historically, the search for planets outside of our solar system has typically been constrained to stars that are similar to the sun. However, Herbig Ae/Be (HAe/Be) stars offer promising results. HAe/Be stars are 2-10 times larger than the sun and retain their formation disks. These disks around these stars are brighter and larger than those around solar type stars, so they …

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Making Mri Scans Quieter Through Time-Reversal Acoustics And Active Noise Control, Trent Furlong, Brian Anderson Jun 2019

Making Mri Scans Quieter Through Time-Reversal Acoustics And Active Noise Control, Trent Furlong, Brian Anderson

Journal of Undergraduate Research

Noise from magnetic resonance imaging (MRI) equipment puts patients at risk for hearing damage.i Active noise control (ANC) systems have been implemented inside the MRI’s bore to reduce perceived noise, but the equipment used cannot have magnetic material or the ANC system will interfere with the MRI machine’s imaging quality. These systems are also limited in size because of the MRI machine’s small bore. Our project was to determine the feasibility of using time-reversal (TR) acoustics to remotely focus a noise-canceling signal to a desired point in space (e.g. a patient’s ear inside an MRI machine) and see if significant …

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Cluster Analysis Via Random Partition Distributions, Brandon Carter, Dr. David B. Dahl Jun 2019

Cluster Analysis Via Random Partition Distributions, Brandon Carter, Dr. David B. Dahl

Journal of Undergraduate Research

Cluster analysis is an important exploratory data analysis technique used in a wide variety of fields. Cluster analysis seeks to discover a natural grouping of the data, where items in the same cluster or group are more similar than items from different clusters. Through our research, we developed a novel method for cluster analysis which takes pairwise distance information as input. Our new method improves upon traditional cluster analysis methods which also take pairwise distance information as input, such as hierarchical clustering. Our method, cluster analysis via random partition distributions (CaviarPD) is based on probability distributions and therefore allows the …

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