Physical Sciences and Mathematics Commons^™

Exploring Consciousness Through The Qualitative Content Of Equations, Ashok Narasimhan, Menas C. Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The majority of the focus on equations in physics has been on the mathematical and computational aspects. Here we focus on the qualitative content of what the relationships expressed in equations imply. In some sense, we are asking foundational questions about the ontology of equations.

Aquatic Food Webs And Heavy Metal Contamination In The Upper Blackfoot River, Montana, Jack E. Landers

Graduate Student Theses, Dissertations, & Professional Papers

Acid mine drainage (AMD), characterized by low pH and abundant heavy metals, is a widespread problem affecting water quality and fish habitat in Montana. Montana’s upper Blackfoot River exhibits impaired water quality from historic mining that has significantly degraded aquatic habitat and reduced fish and invertebrate abundance in impacted streams. The goal of this study is to investigate the direct and indirect effects of mine-related heavy metals contamination on aquatic ecosystems by examining changes in aquatic community composition, bioaccumulation, and toxicity risk of heavy metals along a contamination gradient in the upper Blackfoot River. Three primary research questions were addressed …

Hazardready – A Geographically Based Natural Hazard Education And Preparedness Web Application, Carson C. Macpherson-Krutsky Ms.

Graduate Student Theses, Dissertations, & Professional Papers

Earthquakes, floods, wildfires, and other natural disasters are inevitable and costly both in terms of lives lost and money spent on recovery. Scientific research on natural hazards is widely shared within the scientific community, but is less often made more widely accessible, as methods or pathways for providing scientific natural hazard information and data in non-technical language are limited. Priorities for imparting hazard information include: 1) scientific accuracy, 2) spatial granularity, 3) integration of information about all relevant hazards, 4) nontechnical content, 5) appropriate preparedness activities, and 6) engagement with existing disaster response and mitigation capabilities. In response to these …

Modeling The Cryosphere With Fenics, Evan M. Cummings

Graduate Student Theses, Dissertations, & Professional Papers

This manuscript is a collection of problems and solutions related to modeling the cryosphere using the finite element software FEniCS. Included is an introduction to the finite element method; solutions to a variety of problems in one, two, and three dimensions; an overview of popular stabilization techniques for numerically-unstable problems; and an introduction to the governing equations of ice-sheet dynamics with associated FEniCS implementations. The software developed for this project, Cryospheric Problem Solver (CSLVR), is fully open-source and has been designed with the goal of simplifying many common tasks associated with modeling the cryosphere. CSLVR possesses the ability to download …

An Architecture For Qos-Enabled Mobile Video Surveillance Applications In A 4g Epc And M2m Environment, Mohammad Abu-Lebdeh, Fatna Belqasmi, Roch Glitho

All Works

© 2016 IEEE. Mobile video surveillance applications are used widely nowadays. They offer real-time video monitoring for homes, offices, warehouses, airports, and so on with live and pre-recorded on-demand video streaming. Quality of service (QoS) remains a key challenge faced by most of these applications. In this article, we propose an architecture for mobile video surveillance applications with a guaranteed and differentiated QoS support. The architecture relies on the 3GPP 4G evolved packet core (EPC). The main components are the QoS enabler, media server, and machine-to-machine gateway and surveillance application. To demonstrate its feasibility, a proof of concept prototype has …

An Elastic Hybrid Sensing Platform: Architecture And Research Challenges, Sleiman Rabah, Fatna Belqasmi, Rabeb Mizouni, Rachida Dssouli

All Works

© 2016 Published by Elsevier B.V. The dynamic provisioning of hybrid sensing services that integrates both WSN and MPS is a promising, yet challenging concept. It does not only widen the spatial sensing coverage, but it also enables different types of sensing nodes to collaboratively perform sensing tasks and complement each other. Furthermore, it allows for the provisioning of a new category of services that was not possible to implement in pure WSN or MPS networks. Offering a hybrid sensing platform as a service results in several benefits including, but no limited to, efficient sharing and dynamic management of sensing …

A Saddlepoint Approximation To Left-Tailed Hypothesis Tests Of Variance For Non-Normal Populations, Tyler L. Grimes

UNF Graduate Theses and Dissertations

When the variance of a single population needs to be assessed, the well-known chi-squared test of variance is often used but relies heavily on its normality assumption. For non-normal populations, few alternative tests have been developed to conduct left tailed hypothesis tests of variance. This thesis outlines a method for generating new test statistics using a saddlepoint approximation. Several novel test statistics are proposed. The type-I error rates and power of each test are evaluated using a Monte Carlo simulation study. One of the proposed test statistics, R_gamma2, controls type-I error rates better than existing tests, while having comparable power. …

Vulnerabililty Analysis Of Multi-Factor Authentication Protocols, Keith Garrett

UNF Graduate Theses and Dissertations

In this thesis, the author hypothesizes that the use of computationally intensive mathematical operations in password authentication protocols can lead to security vulnerabilities in those protocols. In order to test this hypothesis: 1. A generalized algorithm for cryptanalysis was formulated to perform a clogging attack (a formof denial of service) on protocols that use computationally intensive modular exponentiation to guarantee security. 2. This technique was then applied to cryptanalyze four recent password authentication protocols, to determine their susceptibility to the clogging attack. The protocols analyzed in this thesis differ in their usage of factors (smart cards, memory drives, etc.) or …

Challenging The Efficient Market Hypothesis With Dynamically Trained Artificial Neural Networks, Kevin M. Harper

UNF Graduate Theses and Dissertations

A review of the literature applying Multilayer Perceptron (MLP) based Artificial Neural Networks (ANNs) to market forecasting leads to three observations: 1) It is clear that simple ANNs, like other nonlinear machine learning techniques, are capable of approximating general market trends 2) It is not clear to what extent such forecasted trends are reliably exploitable in terms of profits obtained via trading activity 3) Most research with ANNs reporting profitable trading activity relies on ANN models trained over one fixed interval which is then tested on a separate out-of-sample fixed interval, and it is not clear to what extent these …

A New Right Tailed Test Of The Ratio Of Variances, Elizabeth Rochelle Lesser

UNF Graduate Theses and Dissertations

It is important to be able to compare variances efficiently and accurately regardless of the parent populations. This study proposes a new right tailed test for the ratio of two variances using the Edgeworth’s expansion. To study the Type I error rate and Power performance, simulation was performed on the new test with various combinations of symmetric and skewed distributions. It is found to have more controlled Type I error rates than the existing tests. Additionally, it also has sufficient power. Therefore, the newly derived test provides a good robust alternative to the already existing methods.

Two Problems Of Gerhard Ringel, Adrian Pastine

Dissertations, Master's Theses and Master's Reports

Gerhard Ringel was an Austrian Mathematician, and is regarded as one of the most influential graph theorists of the twentieth century. This work deals with two problems that arose from Ringel's research: the Hamilton-Waterloo Problem, and the problem of R-Sequences.

The Hamilton-Waterloo Problem (HWP) in the case of C_m-factors and C_n-factors asks whether K_v, where v is odd (or K_v-F, where F is a 1-factor and v is even), can be decomposed into r copies of a 2-factor made entirely of m-cycles and s copies of a 2-factor made entirely of …

Comparison Of Different Seismic Filtering Techniques On Prestack Inversion For Penobscot Area-Nova Scotia, Omer Emre Uygun

Dissertations, Master's Theses and Master's Reports

The goal of this study is to compare three different type of seismic filtering according to their inversion results and their quality of data improvements. To do this bandpass filter, Inverse Q, and Radon transform are applied to the original NMO corrected pre-stack data from Nova-Scotia offshore Canada.

The seismic data used was provided as pre-stack data of generally good quality. The test for quality of data improvement comes from the results of inversion based on different types of filtering performed on the pre-stack gathers.

Bandpass filter, Inverse Q, and Radon transform are applied to the migrated prestack data, over …

Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle

Dissertations, Master's Theses and Master's Reports

Where the proper geological and hydrological conditions exist, natural springs have provided a reliable source of clean water to mankind for eons. Changing climates and land development can negatively impact spring source replenishment and threaten their reliability as a source of water. In the face of prospects of diminishing supplies and increasing population demands, community leaders question whether and how to invest in development for enhancing sustainability and protecting water quality, causing water managers to dispute their reliability given decreasing flows. Springs located in the rugged jungle of western Panama serve as the primary water supply for many indigenous communities, …

Reservoir Estimation In The Penobscot 3d Seismic Volume Using Constrained Sparse Spike Inversion, Offshore Nova Scotia, Canada, Mengchu Xiao

Dissertations, Master's Theses and Master's Reports

The Penobscot study area is located offshore Nova Scotia, Canada. There are two wells, which penetrate the highest potentially commercial bodies in the Abenaki Formation. In order to investigate the potential for locating additional hydrocarbon reservoirs, well log data was used and the Penobscot 3D seismic dataset was analyzed using Constrained Sparse Spike Inversion. From the well log data, low GR and SP values are an indication of a permeable sand layer, which provides the target zone in this study. Impedance – porosity crossplots gave the relationship between impedance and porosity, where a low impedance sand layer is correlated with …

Experimental Study Of The Flow Of Ferrofluid In A Porous Media Under A Magnetic Field, Muskaan Khurana

Dissertations, Master's Theses and Master's Reports

This research presents results from a laboratory-scale experimental setup that was designed to visualize the behavior of ferrofluid percolation through a porous media. Ferrofluids are colloidal suspensions made of magnetic particles of a few nanometers and stabilized in carrier liquids like water or mineral oil. Ferrofluids get magnetized and align themselves in the direction of a magnetic field when a field gradient is applied.

With the help of this experiment we investigate the viability of controlling fluid flow in porous medium by a magnetic field in vicinity. The experiments show that ferrofluids can be used as a transporting media to …

Preliminary Seismic Coda Wave Attenuation Study Of Pacaya Volcano, Guatemala, Maximilian Guettinger

Dissertations, Master's Theses and Master's Reports

Pacaya volcano is a basaltic complex in the Central American Volcanic Arc in Guatemala. Pacaya has been in an open vent condition since 1961. During January 2015 we deployed 19 short period seismometer stations on Pacaya at distances less than 1.5 kilometers from the summit. The resulting data consisted of tremor and thousands of discrete events associated with ongoing outgassing. Where possible, individual events were identified and located. They were found to be high in the edifice near the vent. We used the decaying codas of these events to model the attenuation structure of the Pacaya edifice, following the energy …

Nonlinear Inversion Strategies Applied To Source Characterization And 3d Earthquake Tomography In Volcanic Environments: A Case Study At Pacaya Volcano, Guatemala, Federica Lanza

Dissertations, Master's Theses and Master's Reports

Full-waveform moment tensor inversion of volcanic seismic signals and travel-time 3D tomography of local earthquakes have been widely used to explore source processes related to magma transport as well as to image the location and size of magma storage systems. However, the inversion solutions and the associated reliability estimates are non-unique and bear intrinsic uncertainties due to simplifying assumptions about the source, inaccuracies in the velocity models, dependence on network configuration, and other a priori constraints imposed by the modeler.

This work addresses the non-uniqueness and uncertainties of the model results by introducing non-linear inversion techniques that allow sampling the …

Objective Bayesian Analysis Of A Generalized Lognormal Distribution, Shengnan Li

Dissertations, Master's Theses and Master's Reports

The generalized lognormal distribution plays an important role in various aspects of life testing experiments. We examine Bayesian analysis of this distribution using objective priors (in the general sense of priors constructed using some formal rules) for the model parameters in this paper. Specifically, the derivation of explicit expressions for multiple types of the Jeffreys priors, the reference priors with different group ordering of the parameters, and the first-order matching priors. We investigate the important issue of proper posterior distributions. It is shown that only two of them lead to proper posterior distributions. Monte Carlo simulations are conducted to compare …

Effects Of Wildfire And Post-Fire Salvage Logging On Rill Networks And Sediment Delivery In California Forests, Will Olsen

Dissertations, Master's Theses and Master's Reports

Wildfires can increase soil erosion by orders of magnitude over rates in unburned forests and negatively impact aquatic resources. Rill erosion is a dominant erosion and sediment transport mechanism in burned forests, and hydrologically connected rills can form networks on burned hillslopes. At the swale scale (< 10,000 m²), little is known about how rill networks develop under different burn severities over time, their relationship with sediment yields, and the effect of post-fire salvage logging on rill networks and sediment yields.

The first study assessed rill networks and sediment yields in three burn severities in the inland Coast Range of …

Personas: A Strategy For More Inclusive And Usable Reproductive Health Tracking Technologies, Anna R. Paul

Dissertations, Master's Theses and Master's Reports

In this report, I argue for the inclusion of personas in the development process of technologies that are designed to allow users to collect and track their health information. Personas provide a profile of a user and their needs, goals, and contexts. This tool can help designers to better understand their users, in order to create better, more usable end products. I examine one particular self-tracking technology, smartphone applications that allow users to record information about their menstrual cycles. Many of the most popular period tracking applications available today only meet the needs of a narrow user group, resulting in …

A Small-Scale Water Budget Approach And Water Quality Assessment: A Case Study For Calderas Lake, Guatemala, Edrick Ramos

Dissertations, Master's Theses and Master's Reports

Increases in water demand and urban development in Calderas community over the past decade have led to questions about the hydrology, water quality, quantity and sustainable management of Calderas Lake micro-basin. However, studies on baseline hydrology are limited for rural communities located inside volcanic origin watersheds of Guatemala. The scope of this study was to characterize the hydrology and establish a method to: 1) quantify a water budget, and 2) qualify the water quality of a lacustrine system that supply water for about 17,000 inhabitants on the state limits or rural Guatemala City. Mean annual rainfall and temperature at the …

Understanding The Transition From Secondary Education Mathematics To Undergraduate Mathematics, Amanda D. Stenzelbarton

Dissertations, Master's Theses and Master's Reports

Michigan Technological University had a collective 28% drop, fail, or withdraw rate in four predominantly first-year mathematics classes for the fall semesters from 2011 to 2015, with 58% of students dropping, failing, or withdrawing from College Algebra I in the fall of 2013. A survey was distributed via email to the 2015-2016 first year class of Michigan Tech in an attempt to determine why students struggle in making the transition from high school to undergraduate mathematics class, and what instructors can do to make this transition easier for students. It was found that the time between a student’s last high …

First-Principles Studies Of Group Iv And Group V Related Two Dimensional Materials, Gaoxue Wang

Dissertations, Master's Theses and Master's Reports

Two dimensional (2D) materials have been extensively studied due to their novel properties and technologically important applications. Especially, the discovery of graphene has stimulated an avalanche of investigations to exploit its novel properties for applications at nanoscale. In the post-silicon era, graphene has been widely regarded as the most promising building blocks for the electronic devices. However, its metallic nature together with sensitivity to the environment leads to somewhat limited scope of applications. A finite band gap in a material is known to be essential for the fabrication of devices such as transistors. Such a limitation associated with graphene has …

Representation And Analysis Of Multi-Modal, Nonuniform Time Series Data: An Application To Survival Prognosis Of Oncology Patients In An Outpatient Setting, Jennifer Winikus

Dissertations, Master's Theses and Master's Reports

The representation of nonuniform, multi-modal, time-limited time series data is complex and explored through the use of discrete representation, dimensionality reduction with segmentation based techniques, and with behavioral representation approaches. These explorations are done with a focus on an outpatient oncology setting with the classification and regression analysis being used for length of survival prognosis. Each decision of representation and analysis is not independent, with implications of each decision in method for how the data is represented and then which analysis technique is used. One unique aspect of the work is the use of outpatient clinical data for patients, which …

Influence Of The Weathered Layer On Retrieving Body Wave Using Passive Siesmic Interferometry, Boming Wu

Dissertations, Master's Theses and Master's Reports

Passive seismic interferometry (SI) is an increasingly popular seismic method due to its cost-efficient advantage because it does not need an active source. Techniques in using SI to retrieve surface waves are relatively well established, but using SI to retrieve body waves is still under development by many authors. These geophysicists have proved that many factors, such as average duration of the natural sources, the number of natural sources that occurred during recording time, source distribution, etc., influence the quality of body waves retrieved. In this research, I focus on how to make use of the attenuation property of weathered …

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …

On The Limits And Practice Of Automatically Designing Self-Stabilization, Alex Klinkhamer

Dissertations, Master's Theses and Master's Reports

A protocol is said to be self-stabilizing when the distributed system executing it is guaranteed to recover from any fault that does not cause permanent damage. Designing such protocols is hard since they must recover from all possible states, therefore we investigate how feasible it is to synthesize them automatically. We show that synthesizing stabilization on a fixed topology is NP-complete in the number of system states. When a solution is found, we further show that verifying its correctness on a general topology (with any number of processes) is undecidable, even for very simple unidirectional rings. Despite these negative results, …

Rhyolite And Trachyte Formation At Lake City Caldera: Insight From Quantitative Textural And Geochemical Analyses, Jordan Lubbers

Dissertations, Master's Theses and Master's Reports

Lake City Caldera (22.93 ± 0.02 Ma) is the youngest of 15 Tertiary calderas found within the Southern Rocky Mountain Volcanic Field (SRMVF). Extreme topographical relief of the area reveals the three dimensional exposure of a complex, high-k calc-alkaline, magmatic system, which provides us with the opportunity to study, in detail, how large silicic magmas evolve in the subsurface. The Lake City igneous system is comprised of two major units: a resurgent syenite intrusion and the Sunshine Peak Tuff (Lower, Middle, and Upper). Bulk-rock analyses indicate that the Lower and Middle Sunshine Peak tuff are crystal poor and rhyolitic in …

Diffuse Co2 Degassing And The Origin Of Volcanic Gas Variability From Rincón De La Vieja, Miravalles And Tenorio Volcanoes, Guanacaste Province, Costa Rica, Aurelia Liegler

Dissertations, Master's Theses and Master's Reports

Volcanic gas emissions are an important key component for monitoring volcanic activity and magmatic input of carbon dioxide into the atmosphere as well as the assessment of geothermal potential in volcanic regions. Diffuse soil degassing of CO₂ at Rincón de la Vieja and Miravalles volcanoes, assessed with the commonly accepted accumulation chamber method, showed the concentration of gas emissions in evident hydrothermal surface features in secondary gas emission zones of the volcanoes. Analyses of fumarolic gases were conducted to investigate similarities and differences between the volcanoes and the possibility of continued magma injection into their source(s). An output of …

Testing Lidar-Radar Derived Drop Sizes Against In Situ Measurements, Mary Amanda Shaw

Dissertations, Master's Theses and Master's Reports

How well can a co-located lidar and radar retrieve a drop size distribution in drizzling clouds? To answer, we mimic scattering from a laboratory cloud to retrieve a lidar-radar effective diameter. Using only the shape parameter of the gamma-distributed drops, the mean diameter of the drops can be estimated from lidar-radar effective diameter to within a few percent of the true mean. In practice, the shape parameter of the gamma distribution is not known. To set bounds, mean diameters were calculated from the lidar-radar effective diameter using a range of in situ measured gamma shape parameters. The estimated means varied …