Physical Sciences and Mathematics Commons^™

Designing In-Headset Authoring Tools For Virtual Reality Video, Cuong Nguyen

Dissertations and Theses

Virtual Reality (VR) video is emerging as a new art form. Viewing VR video requires wearing the VR headset to fully experience the immersive surrounding of the content. However, the novel viewing experience of VR video creates new challenges and requirements for conventional video authoring tools, which were designed mainly for working with normal video on a desktop display. Designing effective authoring tools for VR video requires intuitive video interfaces specific to VR.

This dissertation develops new workflows and systems that enable filmmakers to create and improve VR video while fully immersed in a VR headset. We introduce a series …

Non-Native Mangroves (Rhizophora Mangle) Of Moloka'i, Hawai'i: A Socio-Ecological Analysis, Casey Lynette Lewis

Dissertations and Theses

The formation of novel ecosystems by non-native species poses management challenges that are both socially and ecologically complex. This complexity necessitates consideration of both ecological dynamics and social attitudes and perceptions. Red mangrove propagules were introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and they have since spread along the coast and to adjacent islands creating novel habitat. Non-native mangroves in Hawai'i present a unique case study to examine diverse social attitudes and perceptions resulting from a long history of land cover transformations on the Hawaiian Islands, socio-cultural diversity of involved stakeholders, and the potential …

Copper Nanowires Synthesis And Self-Assembly For Interconnect Applications, Srikar Rao Darmakkolla

Dissertations and Theses

One-dimensional (1D) nanomaterial self-assembly offers an excellent approach to the fabrication of highly complex nanodevices. Despite considerable effort and research, precisely controlling the orientation and positioning of nanowires (NWs) on a large-scale area and assembling into a functional device is still a state of the art problem. This thesis focuses on the dimensionally controlled copper nanowires (Cu NWs) synthesis, and magnetic field assisted self-assembly of cupronickel nanowires (Cu/Ni NWs) into interconnect structures on a carbon doped silicon dioxide (CDO) wafer.

CDO is a low dielectric constant (k) material used for copper interconnects in multilayered complex integrated circuits (ICs). …

Investigation Of Aerosol Optical And Chemical Properties Using Humidity Controlled Cavity Ring-Down Spectroscopy, Xijing Zhu

Dissertations and Theses

Scientists have been observing a change in the climate since the beginning of the 20^th century that cannot be attributed to any of the natural influences of the past. Natural and anthropogenic substances and processes perturb the Earth's energy budget, contributing to climate change. In particular, aerosols (particles suspended in air) have long been recognized to be important in processes throughout the atmosphere that affect climate. They directly influence the radiative balance of the Earth's atmosphere, affect cloud formation and properties, and are also key air pollutants that contribute to a variety of respiratory and cardiovascular diseases. Despite their …

Two-Photon Excitation, Fluorescence Microscopy, And Quantitative Measurement Of Two-Photon Absorption Cross Sections, Fredrick Michael Dearmond

Dissertations and Theses

As optical microscopy techniques continue to improve, most notably the development of super-resolution optical microscopy which garnered the Nobel Prize in Chemistry in 2014, renewed emphasis has been placed on the development and use of fluorescence microscopy techniques. Of particular note is a renewed interest in multiphoton excitation due to a number of inherent properties of the technique including simplified optical filtering, increased sample penetration, and inherently confocal operation. With this renewed interest in multiphoton fluorescence microscopy, comes an increased demand for robust non-linear fluorescent markers, and characterization of the associated tool set.

These factors have led to an experimental …

Multi-Dimensional Drought Risk Assessment Based On Socio-Economic Vulnerabilities And Hydro-Climatological Factors, Ali Ahmadalipour

Dissertations and Theses

Drought is among the costliest natural hazards developing slowly and affecting large areas, which imposes severe consequences on society and economy. Anthropogenic climate change is expected to exacerbate drought in various regions of the globe, making its associated socioeconomic impacts more severe. Such impacts are of higher concern in Africa, which is mainly characterized by arid climate and lacking infrastructure as well as social development. Furthermore, the continent is expected to experience vast population growth, which will make it more vulnerable to the adverse effects of drought. This study provides the first comprehensive multi-dimensional assessment of drought risk across the …

Analysis Of The Acid-Base Balance Of Mainstream Tobacco Smoke And Its Effect On The Gas/Particle Partitioning Of Nicotine, Amy Kathleen Devita-Mcbride

Dissertations and Theses

Tobacco smoke particulate matter (PM) is a complex mixture of condensed organic compounds, with about 5 to 10% water. Its general properties are similar in some respects to that of atmospheric organic aerosol PM and thus provides a useful surrogate when studying atmospheric PM. Due to its ability to undergo acid-base chemistry, nicotine is of particular interest in the tobacco smoke system. The gas/particle partitioning of nicotine depends on the protonation state of nicotine in the particles, so the distribution of nicotine between these phases provides a means of understanding the acid-base balance in the tobacco smoke system. The goal …

Assessing The Impact Of Land Use And Travel On Carbon Dioxide Emissions In Portland, Oregon, Zakari Mumuni

Dissertations and Theses

The negative consequences of sprawling metropolitan regions have attracted attention in both academia and in practice regarding how to better design settlements and alter travel behavior in a quest to curtail vehicle emissions. Studies that have attempted to understand the nexus between land use, travel and vehicle emissions have not been able to address the issue of self-selection in a satisfactory manner. Self-selection occurs when households choose their residential location based, in part, on expected travel behavior. This non-random experience makes the use of traditional regression frameworks that strongly rely on random sampling, unsuitable. This replication study's purpose was to …

Investigating Statistics Teachers' Knowledge Of Probability In The Context Of Hypothesis Testing, Jason Mark Asis Dolor

Dissertations and Theses

In the last three decades, there has been a significant growth in the number of undergraduate students taking introductory statistics. As a result, there is a need by universities and community colleges to find well-qualified instructors and graduate teaching assistants to teach the growing number of statistics courses. Unfortunately, research has shown that even teachers of introductory statistics struggle with concepts they are employed to teach. The data presented in this research sheds light on the statistical knowledge of graduate teaching assistants (GTAs) and community college instructors (CCIs) in the realm of probability by analyzing their work on surveys and …

Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack

Dissertations and Theses

Generating MR image contrast from exogenous contrast media through chemical exchange saturation transfer (CEST) offers several exciting new possibilities, such as multicolored imaging, the interleaving of pre- and post-contrast images, and the potential to perform ratiometric metabolic imaging. The major limitation of the deployment of CEST imaging is the comparatively high detection limits of exogenous agents and particularly at the low B_¹ power levels required to meet SAR requirements. The large chemical shifts afforded by paramagnetic (paraCEST) agents permit more rapid exchange kinetics and therefore potentially more effective contrast agents. Despite comparatively large chemical shifts, many Ln³⁺ DOTA-tetraamide …

Improved Scoring Models For Semantic Image Retrieval Using Scene Graphs, Erik Timothy Conser

Dissertations and Theses

Image retrieval via a structured query is explored in Johnson, et al. [7]. The query is structured as a scene graph and a graphical model is generated from the scene graph's object, attribute, and relationship structure. Inference is performed on the graphical model with candidate images and the energy results are used to rank the best matches. In [7], scene graph objects that are not in the set of recognized objects are not represented in the graphical model. This work proposes and tests two approaches for modeling the unrecognized objects in order to leverage the attribute and relationship models to …

Refining Bounding-Box Regression For Object Localization, Naomi Lynn Dickerson

Dissertations and Theses

For the last several years, convolutional neural network (CNN) based object detection systems have used a regression technique to predict improved object bounding boxes based on an initial proposal using low-level image features extracted from the CNN. In spite of its prevalence, there is little critical analysis of bounding-box regression or in-depth performance evaluation. This thesis surveys an array of techniques and parameter settings in order to further optimize bounding-box regression and provide guidance for its implementation. I refute a claim regarding training procedure, and demonstrate the effectiveness of using principal component analysis to handle unwieldy numbers of features produced …

Turbidity Dynamics During High-Flow Storm Events In The Clackamas River, Oregon 2006-2012, Micelis Clyde Doyle

Dissertations and Theses

Turbidity is a useful parameter that can be utilized to help understand the water quality in a river and is an expression of the optical properties of a liquid that cause light rays to be scattered and absorbed rather than transmitted in straight lines. A total of 41 storm events occurring during water years 2006-2012 were analyzed for this study. A hysteresis index (HI) was used to assess the difference in turbidity on the rising and falling limbs of a storm-hydrograph. The upstream Carter Bridge site exhibited a clockwise (C) hysteresis in 38 of 41 storm events and counter-clockwise (CC) …

Investigations Of Electronic Cigarette Chemistry: 1. Formation Pathways For Degradation Products Using Isotopic Labeling; And 2. Gas/Particle Partitioning Of Nicotine And Flavor Related Chemicals In Electronic Cigarette Fluids, Kilsun Kim

Dissertations and Theses

Use of electronic cigarettes (e-cigarettes) is rapidly growing around the world. E-cigarettes are commonly used as an alternative nicotine delivery system, and have been advocated as generating lower levels of harmful chemicals compared to conventional cigarettes. Cigarette smoke-like aerosols are generated when e-cigarettes heat e-liquids. The main components of e-cigarette liquids are propylene glycol (PG) and glycerol (GL) in a varying ratio, plus nicotine and flavor chemicals. Both PG and GL are considered safe to ingest in foods and beverages, but the toxicity of these chemicals in aerosols is unknown. Current studies of e-cigarettes have mainly focused on dehydration and …

Compositional And Physical Gradients In The Magmas Of The Devine Canyon Tuff, Eastern Oregon: Constraints For Evolution Models Of Voluminous High-Silica Rhyolites, Shelby Lee Isom

Dissertations and Theses

Large-volume silicic ignimbrites erupt from reservoirs that vary in composition, temperature, volatile content and crystallinity. The 9.7 Ma Devine Canyon Tuff (DCT) of eastern Oregon is a large-volume (>250 km³), compositionally zoned and variably welded ignimbrite. The ignimbrite exhibits heterogeneous trace element compositions, variable volatile content and crystallinity. These observations were utilized in the investigation into the generation, accumulation and evolution of the magmas composing the DCT. Building off previous research, pumices were selected from the range of trace element compositions and analyzed with respect to crystallinity, mineral abundances and assemblages. The DCT displays a gradational trace …

Constraining The Holocene Extent Of The Northwest Meers Fault, Oklahoma Using High-Resolution Topography And Paleoseismic Trenching, Kristofer Tyler Hornsby

Dissertations and Theses

The Meers Fault (Oklahoma) is one of few seismogenic structures with Holocene surface expression in the stable continental region of North America. Only the ~37 km-long southeastern section of the ~55 km long Meers Fault is interpreted to be Holocene-active. The ~17 km-long northwestern section is considered to be Quaternary-active (pre-Holocene); however, its low-relief geomorphic expression and anthropogenic alteration have presented difficulties in evaluating the fault length and style of Holocene deformation. We reevaluate surface expression and earthquake timing of the northwestern portion of the Meers Fault to improve fault characterization, earthquake rupture models, and seismic hazard evaluations based on …

Invertebrate Community Composition Across Inundation Regimes And Its Potential To Reduce Plant Stress, Inez Ilicia Lawson

Dissertations and Theses

Appreciation of the ecological and economic values associated with healthy salt marshes has led to a recent rise in the number of marshes that are being targeted for restoration by dike removal. The success of restoration is often measured by the return of marsh plants, though this overlooks a key component of salt marshes, that of the invertebrate community within marsh sediments. To evaluate the short-term recovery of these invertebrates, sediment cores were collected across an elevational gradient in a recent dike removal marsh, one and two years post removal, and a nearby reference marsh. Abundance, richness and diversity as …

Detecting Change In Rainstorm Properties From 1977-2016 And Associated Future Flood Risks In Portland, Oregon, Alexis Kirsten Cooley

Dissertations and Theses

In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these characteristics is facilitated by common indices to measure precipitation and temperature developed by the Expert Team on Climate Change Detection and Indices (ETCCDI). These indices can be used to describe the likely consequences of climate change such as increased daily precipitation intensity (SDII) and heavier rainfall events (R95p). This study calculates a subset of these indices from observed and modelled precipitation data in Portland, Oregon. Five rainfall gages from a …

Melting In The Mantle Wedge: Quantifying The Effects Of Crustal Morphology And Viscous Decoupling On Melt Production With Application To The Cascadia Subduction Zone, Jiaming Yang

Dissertations and Theses

Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting and decompression melting due to upward flow. The distribution of melting is sensitive to temperature, the pattern of flow, and the pressure in the mantle wedge. The arc front is the surface manifestation of partial melting in the mantle wedge and is characterized by a narrow chain of active volcanoes that migrate in time. The conventional interpretation is that changes in slab dip angle lead to changes in the arc …

Field Mapping Investigation And Geochemical Analysis Of Volcanic Units Within The Dinner Creek Tuff Eruptive Center, Malheur County, Eastern Oregon, Matthew Cruz

Dissertations and Theses

The Dinner Creek Tuff is a mid-Miocene rhyolitic to dacitic ignimbrite, consisting of four cooling units with ⁴⁰Ar/³⁹Ar ages 16--15 Ma. Previous geologists have suspected that the source of the tuff is located in northwestern Malheur County, eastern Oregon. This broad area is called the Dinner Creek Tuff Eruptive Center.

This thesis summarizes field work, XRF/ICP-MS geochemistry, thin section petrography, and SEM feldspar analysis from the summers of 2015 and 2016. The main purpose of this study is to identify sources for the Dinner Creek Tuff units within the Dinner Creek Tuff Eruptive Center. The secondary purpose …

Development Of Physics Curriculum For Pre-Health Students, Elliot Eckman Mylott

Dissertations and Theses

Many pre-health students are required to take introductory physics as undergraduates, though they often struggle to see the relationship between medicine and what they learn in these courses. In order to help students make that connection, reformed curriculum was adopted that teaches physics through the context of biomedicine. This dissertation will discuss the development, implementation, and assessment of the reformed curriculum for the introductory and intermediate level physics courses that targets the needs of pre-health students.

The curriculum created during this project include laboratory activities, multimedia content, and other instructional materials all of which present physics in biomedical contexts. The …

The Tension Between Technocratic And Social Values In Environmental Decision-Making: An'yang Stream Restoration In South Korea, Chang-Yu Hong

Dissertations and Theses

This dissertation examined the extent to which interests and values of diverse stakeholders were considered through participation-oriented decision-making. It covered the An' Yang Stream restoration case in South Korea, which has been judged a successful stream management endeavor led by public-private partnership governance.

This research utilized a mixed methods approach, combining qualitative and quantitative methods. It addressed the extent to which the collaborative and participatory decision-making processes incorporated diverse stakeholder values and visions. The relevant data on stream restoration was collected through nominal group technique (NGT), analytic hierarchy process (AHP), semi-structured interviews, observations at collaborative stakeholder meetings and workshops, and …

Assessing A Fluorescence Spectroscopy Method For In-Situ Microbial Drinking Water Quality, Taylor Jeffery Sharpe

Dissertations and Theses

Waterborne disease is a significant contributor to the global burden of disease, in particular among high-risk populations in developing nations. State-of-the-art methods for the enumeration of microbial pathogens in drinking water sources have important limitations, including high initial cost, 24-48 hour delays in results, high staffing and facility requirements, and training requirements which all become especially problematic in the developing nation context.

A number of alternative approaches to microbial water quality testing have been proposed, with the goal of decreasing the required testing time, decreasing overall costs, leveraging appropriate technology approaches, or improving sensitivity or specificity of the water quality …

Soputan Volcano, Indonesia: Petrological Systematics Of Volatiles And Magmas And Their Bearing On Explosive Eruptions Of A Basalt Volcano, Syegi Lenarahmi Kunrat

Dissertations and Theses

Soputan volcano is one of the few basaltic volcanoes among 127 active volcanoes in Indonesia. It is part of the Sempu-Soputan volcanic complex located south of Tondano Caldera, North Sulawesi and commonly produces both explosive eruptions with VEI 2-3 and effusive lava dome and flow eruptions. Over the last two decades, Soputan had thirteen eruptions, the most recent in 2016. Most eruptions started explosively, followed by dome growth and in some cases pyroclastic flows. Our study focuses on understanding the magmatic system of Soputan and what processes are responsible for its highly explosive eruptions, which are typically uncommon for a …

Anthropogenic Effects On The Fouling Community: Impacts Of Biological Invasions And Anthropogenic Structures On Community Structure, Whitney Elizabeth Mcclees

Dissertations and Theses

Coastal anthropogenic infrastructure has significantly modified nearshore environments. Because these structures often have a strong association with shipping as would be found in ports and harbors, they have been identified as invasion hotspots. Due to propagule pressure from shipping and recreational boating and suitable uncolonized substrate that provides a refuge from native predators, a greater number of non-native species have been found on these structures compared to nearby natural substrate. The mechanisms that limit the spread of non-native species from anthropogenic structures to natural substrate have been explored for several taxa at a species-specific level, but less so from an …

The Discovery And Development Of Metal-Free Arylation Reactions With Unsymmetrical Diaryliodonium Salts, Sunil Kumar Sundalam

Dissertations and Theses

Functionalizing arenes and heteroarenes has been an active area of research since the 19th century, due to the presence of these molecular structures in many industrially important sectors. A tremendous amount of research has been published in achieving these chemical transformations using stoichiometric reagents and transition metal-catalyzed reactions. However, challenges still remain. An alternative and comparable methodology to metal-catalyzed reactions to overcome the drawbacks will advance this particular area of research is desirable.

Hypervalent iodine compounds offer a promising approach to metal-free arylation reactions. These mild, air and moisture stable compounds have showed significant success as non-toxic and metal-free reagents …

Trade-Offs: The Production Of Sustainability In Households, Kirstin Marie Elizabeth Munro

Dissertations and Theses

Over the past half-century, environmental problems have become increasingly serious and seemingly intractable, and a careless, clueless, or contemptuous consumer is often portrayed as the root cause of this environmental decline. This study takes a different approach to evaluating the demand for resources by households, assessing possible pro-environmental paths forward through a study of highly ecologically-conscious households. By modeling "green" households as producers of sustainability rather than consumers of environmental products, the sustainability work that takes place in households is brought into focus. An investigation of household sustainability production makes possible the evaluation of the trade-offs inherent in these pro-environmental …

Boundary Value Analysis For Input Variables With Functional Dependency, Manmohan Maheshwari

Dissertations and Theses

Software in today’s world is used more and in different ways as well than ever before. From microwaves and vehicles to space rockets and smart cards. Usually, a software programmer goes through a certain process to establish a software that will follow a given specification. Despite the hard work of the programmer, sometimes they make mistakes or sometimes they forget to include all the possibilities of the question for which they are writing the program, which is very humanly in nature. And for those mistakes, a testing unit is always there.

There are numerous techniques of Software Testing, one of …

Knowing Nature In The City: Comparative Analysis Of Knowledge Systems Challenges Along The 'Eco-Techno' Spectrum Of Green Infrastructure In Portland & Baltimore, Annie Marissa Matsler

Dissertations and Theses

Green infrastructure development is desired in many municipalities because of its potential to address pressing environmental and social issues. However, despite technical optimism, institutional challenges create significant barriers to effective green infrastructure design, implementation, and maintenance. Institutional challenges stem from the disparate scales and facility types that make up the concept of green infrastructure, which span from large-scale natural areas to small engineered bioswales. Across these disparate facilities 1) different performance metrics are used, 2) different institutions have jurisdiction, and, 3) facility types are differentially classified as assets, producing epistemological and ontological variegation across the spectrum of green infrastructure that …

Humor Detection, Manan Jain

Dissertations and Theses

Humor is a very complex characteristic concept that defines us as human beings and social entities. Humor is an essential component in personal communication. How to create a method or model to discover the structures behind humor, recognize humor and even extraction of humor remains a challenge because of its subjective nature. Humor also provides valuable information related to linguistic, psychological, neurological and sociological phenomena. However, because of its complexity, humor is still an undefined phenomenon. Because the reaction that make people laugh can hardly be generalized or formalized. For instance, cognitive aspects as well as cultural knowledge, are some …