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Portland State University

University Honors Theses

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Full-Text Articles in Physical Sciences and Mathematics

Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?, Edgar Sanchez Fausto Jun 2021

Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?, Edgar Sanchez Fausto

University Honors Theses

Atmospheric rivers (ARs) play a crucial role in delivering precipitation worldwide. This makes them an important phenomenon for water resource specialists to study. One such interest is to understand what mechanisms make ARs produce significant rainfall and associated hazards such as flooding. One possible mechanism is that AR duration or intensity may increase when it interacts with a secondary cyclone, either of which can increase the AR category scale. The purpose of this study is to determine whether AR and secondary cyclone interactions increase the category scale ARs. Out of 52 AR events analyzed, 32 events contained at least one …


Self-Contained Photon Coincidence Counting With Ni Myrio Ecosystem, Georges Oates Larsen, Andres H. La Rosa Jun 2021

Self-Contained Photon Coincidence Counting With Ni Myrio Ecosystem, Georges Oates Larsen, Andres H. La Rosa

University Honors Theses

Digital coincidence counting units (CCU) have made experimental verification of fundamental quantum mechanical principles financially accessible to undergraduate level teaching programs. However, recent implementations of these systems are not easily ported to National Instruments (NI) FPGAs, making them unsuitable for physics departments that have heavily invested in the NI ecosystem. Therefore, there is clear need for a detailed implementation based on an NI FPGA. We present a formal description of one such implementation, based on the NI myRIO (NI's lower-cost, student-oriented offering) which achieves 6.9 ns minimum guaranteed-distinguishable delay and 32.2 MHz peak coincidence counting rate with four input channels …


Case Study Of Scrum Methodology As Used By A Capstone Team, Lilly I. Yeaton Jun 2021

Case Study Of Scrum Methodology As Used By A Capstone Team, Lilly I. Yeaton

University Honors Theses

Scrum is widely used in the software industry to manage all kinds of projects. This case study examines the way in which a capstone team used the methodology and models the specific project management processes they used over the course of their project. These models and the process modifications therein are then compared to the team’s velocity at different points in the project. The results of this analysis suggest a correlation between asynchronous daily meetings and sprint reviews and improved velocity.


A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix Jun 2021

A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix

University Honors Theses

Over the 2020-2021 Winter, event-based and end-of-season snow samples were collected on Mt. Hood near Government Camp, OR and analyzed for their stable isotopic compositions of 18O and 2H. It was found that surficial snow collected through the winter had higher variation in isotopic values than samples from a snow pit collected in spring. This suggests homogenization occurred in the snowpack over the season from snow metamorphism, sublimation, and/or melting. Homogenization of the snowpack will likely become more pronounced as temperatures increase and rain falls more often than snow due to climate change. Research that utilizes the snowpack …


Automated Decision Making And Machine Learning: Regulatory Alternatives For Autonomous Settings, Alyssa Heminger Jun 2021

Automated Decision Making And Machine Learning: Regulatory Alternatives For Autonomous Settings, Alyssa Heminger

University Honors Theses

Given growing investment capital in research and development, accompanied by extensive literature on the subject by researchers in nearly every domain from civil engineering to legal studies, automated decision-support systems (ADM) are likely to see a place in the foreseeable future. Artificial intelligence (AI), as an automated system, can be defined as a broad range of computerized tasks designed to replicate human neural networks, store and organize large quantities of information, detect patterns, and make predictions with increasing accuracy and reliability. By itself, artificial intelligence is not quite science-fiction tropes (i.e. an uncontrollable existential threat to humanity) yet not without …


Literature Review: Pollutant Removal Efficacy Of Floating Treatment Wetlands Across Water Bodies, Sophie Johnson Jun 2021

Literature Review: Pollutant Removal Efficacy Of Floating Treatment Wetlands Across Water Bodies, Sophie Johnson

University Honors Theses

Wetland numbers are declining worldwide and there is a need to replace the water filtration services they provide. One emerging option is floating treatment wetlands (FTW). FTW are a floating mat that serves as a habitat for aquatic plants whose roots are suspended in the water and that remove both organic and inorganic pollutants like nutrients (nitrogen and phosphorus), potentially toxic metals, and suspended solids. A literature search was performed to examine the efficacy of FTW pollutant removal. Specifically, I inspected 1) how effective FTW are at removing a range of nutrients; 2) what types of plants are most effective …


Understanding Ransomware Trajectory To Create An Informed Prediction, J. D. Klusnick Jun 2021

Understanding Ransomware Trajectory To Create An Informed Prediction, J. D. Klusnick

University Honors Theses

Ransomware is a form of extortion in which digital files are rendered inaccessible until a ransom payment is made. Modern ransomware emerged in 2006 and its destructive influence has been expanding ever since. In recent years cybercriminals have evolved who they target, what computer systems they target, and how they infect those systems. Meanwhile, cybersecurity experts have modelled ransomware methods allowing them to innovate their defense techniques across three paradigms: recovery, detection, and prevention. Ultimately either ransomware attackers or ransomware defenders will dominate this ongoing conflict. A review of the literature indicates that the ransomware crime wave will likely be …


Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts Jun 2021

Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts

University Honors Theses

Soft lithography is a well-established route to wafer-scale reproduction of micro- and nanoscale features in a wide variety of materials. Nevertheless, micron length scales have yet to be explored, despite the potential utility of such structures. Here, polymer micropillars of 6-12 μm length, approximately 0.5-1.5 μm wide at 10 μm spacing are reproduced from a polydimethylsiloxane (PDMS) mold made from patterned cellulose acetate (CA). The patterned CA was cast from a rigid fused silica template machined by a pulsed femtosecond laser. Pore topographic features were successfully reproduced in Norland Optical Adhesive (NOA), polycaprolactone (PCL), Nafion, acrylonitrile butadiene styrene (ABS), and …


Quantifying Biotic Voc Emissions From Moss: Air Quality Impacts Of Isoprene And Monoterpenes In Urban Environments, Danlyn L. Brennan Apr 2021

Quantifying Biotic Voc Emissions From Moss: Air Quality Impacts Of Isoprene And Monoterpenes In Urban Environments, Danlyn L. Brennan

University Honors Theses

Plant-derived biogenic volatile organic compound (VOC) emissions contribute to secondary emissions of molecules such as ground-level ozone (O3) and PM 2.5 which are known to be harmful to the environment and negatively impact human health. Currently, the most known biogenic VOC emissions are from vascular plants like trees and economically significant crops. Air quality models use known emission rates from these measurements and have many unknown sources yet to identify. Unknown values of emissions occur due to a lack of measurements of a wider variety of plants, especially that of smaller and lesser-studied species of bryophytes; mosses. This …


Spanning Trees Of Complete Graphs And Cycles, Minjin Enkhjargal Apr 2021

Spanning Trees Of Complete Graphs And Cycles, Minjin Enkhjargal

University Honors Theses

Spanning trees are typically used to solve least path problems for finding the minimal spanning tree of a graph. Given a number t ≥ 3 what is the least number n = α(t) such that there exists a graph on n vertices having precisely t spanning trees? Specifically, how will the factoring of t with the use of cycles connected by one vertex affect α(t)? Lower and upper bounds of α(t) are graphed by using properties of cycles and complete graphs. The upper bound of α(t) is then improved by constructing a graph of connected cycles {Cp1, C­ …


Group Theory Visualized Through The Rubik's Cube, Ashlyn Okamoto Feb 2021

Group Theory Visualized Through The Rubik's Cube, Ashlyn Okamoto

University Honors Theses

In my thesis, I describe the work done to implement several Group Theory concepts in the context of the Rubik’s cube. A simulation of the cube was constructed using Processing-Java and with help from a YouTube series done by TheCodingTrain. I reflect on the struggles and difficulties that came with creating this program along with the inspiration behind the project. The concepts that are currently implemented at this time are: Identity, Associativity, Order, and Inverses. The functionality of the cube is described as it moves like a regular cube but has extra keypresses that demonstrate the concepts listed. Each concept …


Identification Of Degradation Products Formed From Glycerol And Terpenes In Aromatherapy Vaporizers, Alisha Ortiz Dec 2020

Identification Of Degradation Products Formed From Glycerol And Terpenes In Aromatherapy Vaporizers, Alisha Ortiz

University Honors Theses

Degradation chemistry has been widely studied to assess the safety of aerosols in many fields. The study herein investigates the degradation products formed from MONQ personal aromatherapy devices- a new non-nicotine aromatherapy vape pen device on the market. These pens are marketed to alleviate symptoms of an unrecognized medical syndrome called “terpene deficiency”. These pens contain a glycerin (GL), or glycerol (VG), base and a blend of terpene-rich essential oils. Previous studies have investigated the degradation of both VG and terpenes and have shown that concerning compounds are released in the gas phase, including benzene, benzaldehyde, methacrolein and methyl vinyl …


Interests And Priorities In Sockeye Salmon Management: How Are Policies Enacted And Interpreted On Three Alaskan Rivers?, Jake P. Palazzi Oct 2020

Interests And Priorities In Sockeye Salmon Management: How Are Policies Enacted And Interpreted On Three Alaskan Rivers?, Jake P. Palazzi

University Honors Theses

The large export abundance of Alaskan salmon is well documented, and many studies have been performed to assess the economic and environmental viability of the industry and its management. Less research has been done to characterize how state intentions regarding fisheries allocation are conceived of by management or perceived by vulnerable groups in the user pool. This study seeks to qualitatively characterize the disconnect between state and Native Alaskan perceptions of management effectiveness, public interest, and Native Alaskan involvement using interviews. Results showed that Native Alaskan and state manager respondents had very different perceptions of management effectiveness and equity. When …


Numerical Model Of A Radio Frequency Ion Source For Fusion Plasma Using Particle-In-Cell And Finite Difference Time Domain, Augustin L. Griswold Aug 2020

Numerical Model Of A Radio Frequency Ion Source For Fusion Plasma Using Particle-In-Cell And Finite Difference Time Domain, Augustin L. Griswold

University Honors Theses

Radio frequency (RF) plasma sources are common tool for application and study, and of particular interest for inertial electrostatic (IEC) fusion. Computational analysis is often carried out using particle in cell (PIC) methods or finite difference time domain (FDTD). However, a more holistic analysis is necessary as the particle distribution is highly dependant on the fields created by the plasma source. Herein, an analysis of a particular planar RF electrode with deuterium gas is provided which covers the fields and the particle behaviour using first FDTD then PIC. Further applications are discussed as well as further directions for this study.


Automatic Keyphrase Extraction From Russian-Language Scholarly Papers In Computational Linguistics, Yves Wienecke Jul 2020

Automatic Keyphrase Extraction From Russian-Language Scholarly Papers In Computational Linguistics, Yves Wienecke

University Honors Theses

The automatic extraction of keyphrases from scholarly papers is a necessary step for many Natural Language Processing (NLP) tasks, including text retrieval, machine translation, and text summarization. However, due to the different grammatical and semantic intricacies of languages, this is a highly language-dependent task. Many free and open source implementations of state-of-the-art keyphrase extraction techniques exist, but they are not adapted for processing Russian text. Furthermore, the multi-linguistic character of scholarly papers in the field of Russian computational linguistics and NLP introduces additional complexity to keyphrase extraction. This paper describes a free and open source program as a proof of …


Functional Programming For Systems Software: Implementing Baremetal Programs In Habit, Donovan Ellison Jul 2020

Functional Programming For Systems Software: Implementing Baremetal Programs In Habit, Donovan Ellison

University Honors Theses

Programming in a baremetal environment, directly on top of hardware with very little to help manage memory or ensure safety, can be dangerous even for experienced programmers. Programming languages can ease the burden on developers and sometimes take care of entire sets of errors. This is not the case for a language like C that will do almost anything you want, for better or worse. To operate in a baremetal environment often requires direct control over memory, but it would be nice to have that capability without sacrificing safety guarantees. Rust is a new language that aims to fit this …


The Meaning Of Red And Green In User Interfaces For The Color Deficient, Bassel Hamieh Jul 2020

The Meaning Of Red And Green In User Interfaces For The Color Deficient, Bassel Hamieh

University Honors Theses

Around 108 million web users are color blind which is a problem when the way we communicate over the web or interfaces is through the use of color. Red and green are two colors that are especially heavily used in interface design because of their strong symbolic associations; red being a sign to warn or stop and green being the opposite. This has a large effect on red-green color blind people who are not able to perceive either of those colors correctly. Many solutions exist that aim to help through color differentiation but none take into account color symbolism. With …


Empirical Analysis Of Cbow And Skip Gram Nlp Models, Tejas Menon Jul 2020

Empirical Analysis Of Cbow And Skip Gram Nlp Models, Tejas Menon

University Honors Theses

CBOW and Skip Gram are two NLP techniques to produce word embedding models that are accurate and performant. They were invented in the seminal paper by T. Mikolov et al. and have since observed optimizations such as negative sampling and subsampling. This paper implements a fully-optimized version of these models using Py-Torch and runs them through a toy sentiment/subject analysis. It is weakly observed that different corpus types affect the skew of word embeddings such that fictional corpus are better suited for sentiment analysis and non-fictional for subject analysis.


An Investigation And Comparison Of Stable Isotopes In Meteoric Waters And Groundwaters From Southern Washington, Emily E. Smoot Jun 2020

An Investigation And Comparison Of Stable Isotopes In Meteoric Waters And Groundwaters From Southern Washington, Emily E. Smoot

University Honors Theses

A main source of freshwater in the Pacific Northwest is the Columbia River Basalt Group aquifer system. The semi-arid region of eastern Washington has undergone heavy groundwater depletion in recent decades due to increasing population and expanding agricultural use. Aggressive mining has resulted in drawdowns of up to 30 meters. By using stable isotopes oxygen-eighteen (18O) and deuterium (D), this study confines the timing of groundwater precipitation and proposes an explanation for why drawdowns are so significant. The isotopic composition of meteoric water is compared to groundwaters from southeast Washington. The two populations are statistically different (p < 0.001, alpha = 0.05). The isotopic composition of groundwaters from the deepest wells (< -150 m msl) are isotopically lighter than meteoric waters and not achievable by recharge under the current climate. These deep groundwaters are interpreted to have precipitated during the Last Glacial Maximum in the late Pleistocene and finished precipitating roughly 5 ka. Thus, replenishment of the aquifer cannot be expected to keep pace with extraction. Additionally, this research examines the elevation response in the stable isotope signature of meteoric water along the 47° N latitude by computing three lapse rates for 18 …


A Review Of Methodologies Applied For Determining Particulate Matter Characterization In Urban Regions, Garrett F. Diehl Jun 2020

A Review Of Methodologies Applied For Determining Particulate Matter Characterization In Urban Regions, Garrett F. Diehl

University Honors Theses

This is a literature review on previous research conducted on particulate matter deposited on urban vegetation. This was accomplished by searching six databases, that uncovered 37 peer-reviewed journal articles. The main objective of this review is to present the methodology and findings of the articles analyzed to demonstrate how research in this area of study is being conducted. The findings show that there are variations in the literature and that many variables are not being incorporated into the methods and analyses of particulate matter found on urban vegetation. Understanding how different studies have analyzed particulate matter found on urban vegetation …


Projections Of Change In Frequency And Persistence In Atmospheric Ridging Over The Pacific Northwest Using Cmip6 Models, Ellen Koukel May 2020

Projections Of Change In Frequency And Persistence In Atmospheric Ridging Over The Pacific Northwest Using Cmip6 Models, Ellen Koukel

University Honors Theses

The hydroclimatology of the Pacific Northwest is characterized by wet winters and dry summers; however, the end of the rainy season is subject to considerable year-to-year variability. Early onset of the dry season can introduce challenges for water resource managers. Historically, anomalously dry springs are the result of persistent atmospheric ridging, with notable examples in May 2015 and 2018. As climate change may affect the persistence and frequency of ridges, it is important to understand potential changes in springtime ridging. Future changes will have implications for the length of the rainy season and consequently freshwater availability throughout the region. Therefore, …


Inhibition Of Cancer Causing Genes Through The Delivery Of Omomyc In Anti-Myc Therapy: A Systematic Review, Angie Mcgraw May 2020

Inhibition Of Cancer Causing Genes Through The Delivery Of Omomyc In Anti-Myc Therapy: A Systematic Review, Angie Mcgraw

University Honors Theses

A systematic review of the available studies on the interference of OmoMyc with Myc's function in cancerous cells is presented. Myc is a transcription factor that regulates cellular processes such as apoptosis, proliferation, and differentiation. However, Myc is often overexpressed in a variety of cancers, resulting in abnormal growth of cancer cells. Although the inhibition of Myc has been highly desired, it remained a challenge due to its undruggable characteristics. Attempts to inhibit Myc have involved the usage of small-molecules, but these attempts have failed, causing adverse effects and incomplete inhibition of Myc. Despite promising preclinical studies of OmoMyc, it …


Fallen Objects: Collaborating With Artificial Intelligence In The Field Of Graphic Design, Harrison S. Gerard May 2020

Fallen Objects: Collaborating With Artificial Intelligence In The Field Of Graphic Design, Harrison S. Gerard

University Honors Theses

In this paper, I discuss the creation, execution and reception of my digital art series Fallen Objects, in which I collaborate with a neural net to create pseudo-found objects. I explore how artists might collaborate with Artificial Intelligence obliquely, not by having the AI generate the images themselves, but instead generate input for the artists to make the images. While many artists are focused on training neural nets to replicate their own art inputs, I instead focus on working with an AI trained on external, easily-accessible data and creating images from the prompts it delivers. In this way, the AI …


On Dc And Local Dc Functions, Liam Jemison May 2020

On Dc And Local Dc Functions, Liam Jemison

University Honors Theses

In this project we investigate the class of functions which can be represented by a difference of convex functions, hereafter referred to simply as 'DC' functions. DC functions are of interest in optimization because they allow the use of convex optimization techniques in certain non-convex problems. We present known results about DC and locally DC functions, including detailed proofs of important theorems by Hartman and Vesely.

We also investigate the DCA algorithm for optimizing DC functions and implement it to solve the support vector machine problem.


Facilitating Mixed Self-Timed Circuits, Alexandra R. Hanson May 2020

Facilitating Mixed Self-Timed Circuits, Alexandra R. Hanson

University Honors Theses

Designers constrain the ordering of computation events in self-timed circuits to ensure the correct behavior of the circuits. Different circuit families utilize different constraints that, when families are combined, may be more difficult to guarantee in combination without inserting delay to postpone necessary events. By analyzing established constraints of different circuit families like Click and GasP, we are able to identify the small changes necessary to either 1) avoid constraints entirely; or 2) decrease the likelihood of necessary delay insertion. Because delay insertion can be tricky for novice designers and because the likelihood of its requirement increases when mixing different …


Effect Of Parasitic Orobanche Uniflora On Sedum Plants And The Potential Implications For Urban Green Roofs, Jessica Bigger May 2020

Effect Of Parasitic Orobanche Uniflora On Sedum Plants And The Potential Implications For Urban Green Roofs, Jessica Bigger

University Honors Theses

An increasing presence of the parasitic plant Orobanche uniflora has been observed on green roofs in urban areas such as Portland, Oregon. Although little is known about these plants, they are believed to be detrimental to host plants such as sedums that grow on green roofs. Orobanche uniflora takes over the host plant’s cellular structure and uses this to take in nutrients. This poses a problem for green roof succulents because if the host plants are killed by the parasite then the green roofs will not be able to function as effectively. Green roofs may also be contributing to an …


Post-Fire Changes In Interior Alaska's Vegetation Composition, Jannike E. Allen May 2020

Post-Fire Changes In Interior Alaska's Vegetation Composition, Jannike E. Allen

University Honors Theses

Global warming is altering the fire regime of interior Alaska, which may have cascading effects on the prevalence of forest types and species dominance across this region. Our objective was to investigate the relationship between vegetation composition and fire in the boreal forest of interior Alaska. We utilized data from over 700 plots sampled across the landscape designated as the Tanana region by the US Forest Service for Forest Inventory Analysis (FIA), as well as fire history records. We compared biomass and stem density of conifer and hardwood forest types, as well as individual tree species, across a gradient of …


Laurent Series Expansion And Its Applications, Anna Sobczyk May 2020

Laurent Series Expansion And Its Applications, Anna Sobczyk

University Honors Theses

The Laurent expansion is a well-known topic in complex analysis for its application in obtaining residues of complex functions around their singularities. Computing the Laurent series of a function around its singularities turns out to be an efficient way to determine the residue of the function as well as to compute the integral of the function along any closed curves around its singularities. Based on the theory of the Laurent series, this paper provides several working examples where the Laurent series of a function is determined and then used to calculate the integral of the function along any closed curve …


Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns Apr 2020

Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns

University Honors Theses

The application of silicon nanoparticles varies from energy storage materials, to drug-delivery, and molecular recognition. Various chemical and physical properties of the Si nanoparticles arise from their morphology. This paper aims to reveal the morphology of Si nanoparticles following magnesiothermic reduction of silica (SiO2) nanoparticles. Two sets of SiO2 nanoparticles were used, commercially available NanoXact nanoparticles and laboratory-synthesized Stöber nanoparticles. A Zeiss Sigma VP FEG SEM was used to examine the morphology. Following the magnesiothermic reduction, the nanoparticles were etched with HF. Ten sets of images were taken of both Stöber and NanoXact nanoparticles: 1,2: the SiO …


Modeling And Visualizing Power Amplification In Fiber Optic Cables, Gil Parnon Mar 2020

Modeling And Visualizing Power Amplification In Fiber Optic Cables, Gil Parnon

University Honors Theses

Transverse mode instability in fiber optic cables causes power amplification to exhibit chaotic behavior. Due to this, numerical modeling of fiber optic power amplification is extremely computationally expensive. In this paper I work through modeling similar behavior in a simpler system. I also visualize the three-dimensional phase portrait of the system in order to better understand the behavior and hopefully relate it to more well-understood problems.