Physical Sciences and Mathematics Commons^™

Contributions To The Solution Of Large Nonlinear Systems Via Model-Order Reduction And Interval Constraint Solving Techniques, Leobardo Valera

Open Access Theses & Dissertations

Many engineering problems boil down to solving partial differential equations (PDEs) that describe real-life phenomena. Nevertheless, efficiently and reliably solving such problems constitutes a major challenge in computational sciences and in engineering in general.

PDE-based systems can reach sizes so large after they are discretized. The large size in these problems generate several issues, among them we can mention: large space of storing, computing time, and the most important, lost of accuracy. A popular approach to solving such problems is assume that the PDE's solution is in a subspace, and the solution is sought there. This assumption and later searching …

An Assessment Of The Role Of Roads In Population Demography And Genetic Structuring In Two Species Of Lizards In The Northern Chihuahuan Desert, Kevin Floyd

Open Access Theses & Dissertations

Roads can fragment habitat and increase mortality rates of wildlife, potentially reducing population sizes and gene flow, which in turn can reduce genetic diversity through genetic drift. Although negative road impacts have been found in a variety of taxa, not all species are impacted. For instance, species that move less and rarely encounter roads and those that avoid the roads are predicted to not be negatively affected. Yet tests of these predictions are uncommon, especially for reptiles and particularly lizards. Side-blotched lizards (Uta stansburiana) are small sit-and-wait predators, while the larger marbled whiptails (Aspidoscelis marmorata) are active foragers. Their responses …

Effect Of Strain On Ferroelectric Field Effect In Strongly Correlated Oxide Sm0.5nd0.5nio3, L. Zhang, X. G. Chen, H. J. Gardner, M. A. Koten, J. E. Shield, X. Hong

Xia Hong Publications

We report the effect of epitaxial strain on the magnitude and retention of the ferroelectric field effect in high quality PbZr_0.3Ti_0.7O₃ (PZT)/3.8-4.3 nm Sm_0.5Nd_0.5NiO₃ (SNNO) heterostructures grown on (001) LaAlO₃ (LAO) and SrTiO₃ (STO) substrates. For SNNO on LAO, which exhibits a first-order metal-insulator transition (MIT), switching the polarization of PZT induces a 10 K shift in the transition temperature T_MI, with a maximum resistance change between the on and off states of Δ𝑅/𝑅_on ~75%. In sharp contrast, only up to 5% resistance change has …

Multiferroic Tunnel Junctions And Ferroelectric Control Of Magnetic State At Interface, Y. W. Yin, M. Raju, W. J. Hu, John D. Burton, Y.-M. Kim, A. Y. Borisevich, S. J. Pennycook, S. M. Yang, T. W. Noh, Alexei Gruverman, X. G. Li, Z. D. Zhang, Evgeny Y. Tsymbal, Qi Li

Alexei Gruverman Publications

As semiconductor devices reach ever smaller dimensions, the challenge of power dissipation and quantum effect place a serious limit on the future device scaling. Recently, a multiferroic tunnel junction (MFTJ) with a ferroelectric barrier sandwiched between two ferromagnetic electrodes has drawn enormous interest due to its potential applications not only in multi-level data storage but also in electric field controlled spintronics and nanoferronics. Here, we present our investigations on four-level resistance states, giant tunneling electroresistance (TER) due to interfacial magnetoelectric coupling, and ferroelectric control of spin polarized tunneling in MFTJs. Coexistence of large tunneling magnetoresistance and TER has been observed …

Anomalous Nonlinear X-Ray Compton Scattering, Matthias Fuchs, Mariano Trigo, Jian Chen, Shambhu Ghimire, Sharon Shwartz, Michael Kozina, Mason Jiang, Thomas Henighan, Crystal Bray, Georges Ndabashimiye, Philip H. Bucksbaum, Yiping Feng, Sven Herrmann, Gabriella A. Carini, Jack Pines, Philip Hart, Christopher Kenney, Serge Guillet, Sébastien Boutet, Garth J. Williams, Marc Messerschmidt, M. Marvin Seibert, Stefan Moeller, Jerome B. Hastings, David A. Reis

Matthias Fuchs Publications

X-ray scattering is typically used as a weak linear atomic-scale probe of matter. At high intensities, such as produced at free-electron lasers, nonlinearities can become important, and the probe may no longer be considered weak. Here we report the observation of one of the most fundamental nonlinear X-ray–matter interactions: the concerted nonlinear Compton scattering of two identical hard X-ray photons producing a single higher-energy photon. The X-ray intensity reached 4 × 10²⁰ W cm⁻², corresponding to an electric field well above the atomic unit of strength and within almost four orders of magnitude of the quantum-electrodynamic critical …

The Ugly Duckling: Insights Into Ancient Maya Commerce And Industry From Pottery Petrography, James Aimers, Elizabeth Haussner, Dori Farthing

Anthropology

No abstract provided.

Spe: Security And Privacy Enhancement Framework For Mobile Devices, Brian Krupp, Nigamanth Sridhar, Wenbing Zhao

Electrical and Computer Engineering Faculty Publications

In this paper, we present a security and privacy enhancement (SPE) framework for unmodified mobile operating systems. SPE introduces a new layer between the application and the operating system and does not require a device be jailbroken or utilize a custom operating system. We utilize an existing ontology designed for enforcing security and privacy policies on mobile devices to build a policy that is customizable. Based on this policy, SPE provides enhancements to native controls that currently exist on the platform for privacy and security sensitive components. SPE allows access to these components in a way that allows the framework …

Comparison Of Live Response, Linux Memory Extractor (Lime) And Mem Tool For Acquiring Android’S Volatile Memory In The Malware Incident, Andri Heriyanto, Craig Valli, Peter Hannay

Australian Digital Forensics Conference

The increasing use of encryption and obfuscation within the malware development arena has necessitated the use of volatile memory acquisition on smartphone platforms. Current smartphone forensics research lacks a well-formulated process for the acquisition of volatile memory. This research evaluates and contrasts three differing tools for acquisition of volatile memory from the Android platform: Live Response, Linux Memory Extractor (LiME) and Mem Tool. Evaluation is conducted through practical examination during the analysis of an infected device. The results demonstrate a combination of LiME and the Volatility Framework provides the most robust findings. Complexities due to the nature of LiME prevent …

Mining Social Networking Sites For Digital Evidence, Brian Cusack, Saud Alshaifi

Australian Digital Forensics Conference

OnLine Social Networking sites (SNS) hold a vast amount of information that individuals and organisations post about themselves. Investigations include SNS as sources of evidence and the challenge is to have effective tools to extract the evidence. In this exploratory research we apply the latest version of a proprietary tool to identify potential evidence from five SNS using three different browsers. We found that each web browser influenced the scope of the evidence extracted. In previous research we have shown that different open source and proprietary tools influence the scope of evidence obtained. In this research we asked, What variation …

The Challenges Of Seizing And Searching The Contents Of Wi-Fi Devices For The Modern Investigator, Dan Blackman, Patryk Szewczyk

Australian Digital Forensics Conference

To the modern law enforcement investigator, the potential for an offender to have a mobile device on his or her person, who connects to a Wi-Fi network, may afford evidence to place them at a scene, at a particular time. Whilst tools to interrogate mobile devices and Wi-Fi networks, have undergone significant development, little research has been conducted with regards to interrogating Wi-Fi routers and the evidence they may contain. This paper demonstrates that multiple inhibiting factors exist for forensic investigators when attempting to extract data from Wi-Fi routers at the scene. Data volatility means the Wi-Fi router cannot be …

Image Similarity Using Dynamic Time Warping Of Fractal Features, Ahmed Ibrahim, Craig Valli

Australian Digital Forensics Conference

Hashing algorithms such as MD/SHA variants have been used for years by forensic investigators to look for known artefacts of interest such as malicious files. However, such hashing algorithms are not effective when their hashes change with the slightest alteration in the file. Fuzzy hashing overcame this limitation to a certain extent by providing a close enough measure for slight modifications. As such, image forensics is an essential part of any digital crime investigation, especially in cases involving child pornography. Unfortunately such hashing algorithms can be thwarted easily by operations as simple as saving the original file in a different …

Relative Importance Of Nutrient Load And Wind On Regulating Interannual Summer Hypoxia In The Chesapeake Bay, P Wang, Harry V. Wang, L Linker

VIMS Articles

No abstract provided.

Professional Formation Of Engineers: Enhancing The First Year Student Experience, Eileen Goold

Conference Papers

This paper reports on a study investigating engineering students’ perceptions of engineering practice and whether engineering students’ cognitive engagement benefits from bridging the gap between the technical issues in their education and the practical realities of modern engineering practice.

Simultaneous Modelling Of Initial Conditions And Time Heterogeneity In Dynamic Networks: An Application To Foreign Direct Investments, Johan Koskinen, Alberto Caimo, Alessandro Lomi

Articles

In dynamic networks, the presence of ties are subject both to endogenous network dependencies and spatial dependencies. Current statistical models for change over time are typically defined relative to some initial condition, thus skirting the issue of where the first network came from. Additionally, while these longitudinal network models may explain the dynamics of change in the network over time, they do not explain the change in those dynamics. We propose an extension to the longitudinal exponential random graph model that allows for simultaneous inference of the changes over time and the initial conditions, as well as relaxing assumptions of …

Salient Object Detection Via Objectness Proposals, Tam Nguyen

Computer Science Faculty Publications

Salient object detection has gradually become a popular topic in robotics and computer vision research. This paper presents a real-time system that detects salient objects by integrating objectness, foreground, and compactness measures. Our algorithm consists of four basic steps. First, our method generates the objectness map via object proposals. Based on the objectness map, we estimate the background margin and compute the corresponding foreground map which prefers the foreground objects. From the objectness map and the foreground map, the compactness map is formed to favor the compact objects. We then integrate those cues to form a pixel-accurate saliency map which …

Voc Emissions From Beef Feedlot Pen Surfaces As Affected By Within-Pen Location, Moisture And Temperature, Bryan L. Woodbury, John E. Gilley, David B. Parker, David B. Marx, Roger A. Eigenberg

Department of Statistics: Faculty Publications

A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface materials were collected from the feed trough (bunk), drainage, and raised areas (mounds) within three feedlot pens. The surface materials were mixed with water to represent dry, wet, or saturated conditions and then incubated at temperatures of 5, 15, 25 and 35 C. A wind tunnel and gas chromatograph-mass spectrometer were used to collect and quantify …

Ecology, Population Dynamics, And Sexual Characteristics Of Commensal Leucothoid Amphipods With The Sponge Cliona Varians In The Florida Keys (Crustacea: Amphipoda), Stephanie Lynn Andringa

HCNSO Student Theses and Dissertations

Recent observations have identified a new species of leucothoid amphipod, Leucothoe “sp. F,” associated with the sponge Cliona varians. This project examined the relationship between this amphipod and its sponge host at three sites in the Florida Keys with differing hydrodynamic regimes. Ninety-eight sponge samples with a total of 2,030 amphipods were collected between December 2011 and September 2012. Leucothoe “sp. F” is currently a common species in the Florida Keys strongly associated with C. varians; its distribution strongly coincides with open tidal currents from the Gulf of Mexico. Seasonality, depth, and tidal regimes not only influence population …

Feeding Ecology And Habitat Utilization Of The Great Barracuda Sphyraena Barracuda (Edwards 1771) In Southeast Florida, Noah R. Hansen

HCNSO Student Theses and Dissertations

Great barracuda Sphyraena barracuda is a large predatory teleost found circumglobally, other than the Eastern Pacific Ocean. The species is commonly caught by both recreational and commercial fishermen as bycatch while targeting other, more economically or recreationally valuable fishes. This species also exhibits an ontogenetic shift in habitat, with juveniles inhabiting mangrove and seagrass habitats, while adults live near offshore reefs and associated structure.

This thesis consists of two separate studies of S. barracuda: 1) feeding ecology along an ontogenetic gradient and 2) habitat utilization of as derived through electronic tagging. The first chapter of this thesis describes the …

Caffeine Elicits Time Dependent Biphasic Response Of Functional Recovery In Carassius Auratus Hemilabyrinthectomy Lesion Model, Bethany Brockhoff

HCNSO Student Theses and Dissertations

Caffeine is one of the most popular psychostimulant drugs worldwide. Its effects are exerted through a variety of complex mechanisms, apparently primarily via interactions with adenosine A1 and A2A receptors. This drug has also been proven to elicit neuroprotective responses in a number of different brain disorders of the Central Nervous System (CNS), as well as provide enhancement of cognitive abilities. Moreover, a biphasic set of functional and structural neurological changes are often found in these receptors among diverse vertebrates. I investigated the effects of chronic caffeine exposure on functional recovery of the dorsal light reflex (DLR) in hemilabyrinthectomized common …

Translocation Of Acropora Cervicornis Across Geographic Regions: Investigating Species Recovery And Restoration, Bradley Cody Bliss

HCNSO Student Theses and Dissertations

This thesis is the first known study to relocate Acropora cervicornis across multiple regions of the Florida Reef Tract. Since 2006, A. cervicornis has been listed as a threatened coral species under the U.S. Endangered Species Act. In response, restoration efforts utilizing coral nursery methods have been implemented throughout the Caribbean. The primary objective of this research was to determine the response of A. cervicornis colonies to being relocated between two coral nurseries separated by approximately 150km along the Florida Reef Tract. To accomplish this, a reciprocal transport was conducted between coral fragments with known genotypes from Broward County and …

Feasibility Of Using Biofuel By-Products As A Sustainable Nutritional Resource For Aquaculture Production Of Litopenaeus Vannamei, Erik David Demicco

HCNSO Student Theses and Dissertations

Many different algal species can provide an acceptable protein ingredient, with good digestibility, for shrimp feeds. Compared to fish meal, similar protein, carbohydrate, and lipid levels can be found in select algal species. Traditional shrimp diets in aquaculture rely on fish meal and fish oil from pelagic fish fisheries. A reduction or elimination of these ingredients would reduce the dependency of shrimp aquaculture on offshore fisheries and increase economic competiveness. Biofuel production produces algal by-products of potential use to aquaculturists that might reduce or eliminate the need for fisheries products in shrimp feed. Established uses for by-products from biofuel production …

The Impacts Of Health Status And Exposure To Environmental Toxins On Children's Grade Point Average In El Paso, Texas, Stephanie Elizabeth Clark

Open Access Theses & Dissertations

Studies in the US have found that both exposure to environmental toxins and children's general health status negatively impact children's academic achievement. This Thesis will be made of up two papers. The first examines the impact of exposure to residential air toxins from a variety of sources on student's academic achievement and the second paper incorporates a measure of children's general health status into the statistical model from the first paper. This Thesis employs National Air Toxics Assessment (NATA) risk estimates from a variety of sources and individual-level data collected through a mail survey of fourth and fifth grade school …

Investigating Endocrine And Physiological Parameters Of Captive American Kestrels Exposed By Diet To Selected Organophosphate Flame Retardants, Kimberly J. Fernie, Vince Palace, Lisa E. Peters, Nil Basu, Robert J. Letcher, Natalie K. Karouna-Renier, Sandra L. Schultz, Rebecca S. Lazarus, Barnett A. Rattner

United States Geological Survey: Staff Publications

Organophosphate triesters are high production volume

additive flame retardants (OPFRs) and plasticizers. Shown to accumulate

in abiotic and biotic environmental compartments, little is known about the

risks they pose. Captive adult male American kestrels (Falco sparverius) were

fed the same dose (22 ng OPFR/g kestrel/d) daily (21 d) of tris(2-

butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP),

tris(2-chloroisopropyl) phosphate (TCIPP), or tris(1,2-dichloro-2-propyl)

phosphate (TDCIPP). Concentrations were undetected in tissues (renal,

hepatic), suggesting rapid metabolism. There were no changes in glutathione

status, indicators of hepatic oxidative status, or the cholinergic system (i.e.,

cerebrum, plasma cholinesterases; cerebrum muscarinic, nicotinic receptors).

Modest …

Interactive Effects Of Climate Change With Nutrients, Mercury, And Freshwater Acidification On Key Taxa In The North Atlantic Landscape Conservation Cooperative Region, Alfred E. Pinkney, Charles T. Driscoll, David C. Evers, Michael J. Hooper, Jeffrey Horan, Jess W. Jones, Rebecca S. Lazarus, Harold G. Marshall, Andrew Milliken, Barnett A. Rattner, John Schmerfeld, Donald W. Sparling

United States Geological Survey: Staff Publications

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public–private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using …

Use Of Terrestrial Field Studies In The Derivation Of Bioaccumulation Potential Of Chemicals, Nico W. Van Den Brink, Jennifer A. Arblaster, Sarah R. Bowman, Jason M. Conder, John E. Elliott, Mark S. Johnson, Derek C.G. Muir, Tiago Natal-Da-Luz, Barnett A. Rattner, Bradley E. Sample, Richard F. Shore

United States Geological Survey: Staff Publications

Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be …

Estimating Relative Sea-Level Rise And Submergence Potential At A Coastal Wetland, Donald R. Cahoon

United States Geological Survey: Staff Publications

A tide gauge records a combined signal of the vertical change (positive or negative) in the level of both the sea and the land to which the gauge is affixed; or relative sealevel change, which is typically referred to as relative sea-level rise (RSLR). Complicating this situation, coastal wetlands exhibit dynamic surface elevation change (both positive and negative), as revealed by surface elevation table (SET) measurements, that is not recorded at tide gauges. Because the usefulness of RSLR is in the ability to tie the change in sea level to the local topography, it is important that RSLR be calculated …

Training Conservation Practitioners To Be Better Decision Makers, Fred Johnson, Mitchell J. Eaton, James H. Williams, Gitte H. Jensen, Jesper Madsen

United States Geological Survey: Staff Publications

Traditional conservation curricula and training typically emphasizes only one part of systematic decision making (i.e., the science), at the expense of preparing conservation practitioners with critical skills in values-setting, working with decision makers and stakeholders, and effective problem framing. In this article we describe how the application of decision science is relevant to conservation problems and suggest how current and future conservation practitioners can be trained to be better decision makers. Though decision-analytic approaches vary considerably, they all involve: (1) properly formulating the decision problem; (2) specifying feasible alternative actions; and (3) selecting criteria for evaluating potential outcomes. Two approaches …

Training Conservation Practitioners To Be Better Decision Makers, Fred Johnson, Mitchell J. Eaton, James H. Williams, Gitte H. Jensen, Jesper Madsen

United States Geological Survey: Staff Publications

Traditional conservation curricula and training typically emphasizes only one part of systematic decision making (i.e., the science), at the expense of preparing conservation practitioners with critical skills in values-setting, working with decision makers and stakeholders, and effective problem framing. In this article we describe how the application of decision science is relevant to conservation problems and suggest how current and future conservation practitioners can be trained to be better decision makers. Though decision-analytic approaches vary considerably, they all involve: (1) properly formulating the decision problem; (2) specifying feasible alternative actions; and (3) selecting criteria for evaluating potential outcomes. Two approaches …

Sediment And Discharge Yields Within A Minimally Disturbed, Headwater Watershed In North Central Pennsylvania, Usa, With An Emphasis On Superstorm Sandy, Kelly O. Maloney, Dustin R. Shull

United States Geological Survey: Staff Publications

We estimated discharge and suspended sediment (SS) yield in a minimally disturbed watershed in North Central Pennsylvania, USA, and compared a typical storm (September storm, 4.80 cm) to a large storm (Superstorm Sandy, 7.47 cm rainfall). Depending on branch, Sandy contributed 9.7–19.9 times more discharge and 11.5–37.4 times more SS than the September storm. During the September storm, the upper two branches accounted for 60.6% of discharge and 88.8% of SS at Lower Branch; during Sandy these percentages dropped to 36.1% for discharge and 30.1% for SS. The branch with close proximity roads had over two-three times per area SS …

Aquatic Pollution Increases Use Of Terrestrial Prey Subsidies By Stream Fish, Johanna M. Kraus, Justin F. Pomeranz, Andrew S. Todd, David M. Walters, Travis S. Schmidt, Richard B. Wanty

United States Geological Survey: Staff Publications

1. Stream food webs are connected with their riparian zones through cross-ecosystem movements of energy and nutrients. The use and impact of terrestrial subsidies on aquatic consumers is often determined by in situ biomass of aquatic prey. Thus, stressors such as aquatic pollutants that greatly reduce aquatic secondary production could increase the need for and reliance of stream consumers on terrestrial resource subsidies.

2. To test this hypothesis, we surveyed stream fish, their diets, and resource availability in 16 subalpine streams over a regional gradient of trace metals known to strongly impact aquatic insect communities (i.e. fish prey) in …