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Articles 56851 - 56880 of 302562

Full-Text Articles in Physical Sciences and Mathematics

The Impacts Of Climate And Landscape Change On Catchment Scale Material Transport In High Mountain And Seasonally Cold Regions, John R. Slosson Jul 2021

The Impacts Of Climate And Landscape Change On Catchment Scale Material Transport In High Mountain And Seasonally Cold Regions, John R. Slosson

Dissertations - ALL

Streamflow in high mountain and seasonally cold regions follows annual patterns that can make water quality and availability in these areas uniquely susceptible to changes in climate and land use. Precipitation in the form of snow accumulates during the winter months and gradually melts in the spring, leading to elevated streamflow that serves important ecological and human needs. This simple winter storage and spring release dynamic is especially sensitive to warming temperatures, which can result in a greater fraction of winter precipitation falling as rain and an earlier arrival of the hydrograph center of timing, with cascading effects on surrounding …


Quo Vadis Lakes Azuei And Enriquillo: A Future Outlook For Two Of The Caribbean Basin's Largest Lakes, Mahrokh Moknatian, Michael Piasecki Jul 2021

Quo Vadis Lakes Azuei And Enriquillo: A Future Outlook For Two Of The Caribbean Basin's Largest Lakes, Mahrokh Moknatian, Michael Piasecki

Publications and Research

Lakes Azuei (LA) and Enriquillo (LE) on Hispaniola Island started expanding in 2005 and continued to do so until 2016. After inundating large swaths of arable land, submerging a small community, and threatening to swallow a significant trade route between the Dominican Republic and Haiti; worries persisted at how far this seemingly unstoppable expansion would go. The paper outlines the approach to a look forward to answer this question vis-à-vis climate change scenarios developed by the Intergovernmental Panel on Climate Change (IPCC). It uses numerical representations of the two lakes, and it examines how the lakes might evolve, deploying three …


Nonlinear Schrödinger Equation Solitons On Quantum Droplets, A. Ludu, A.S. Carstea Jul 2021

Nonlinear Schrödinger Equation Solitons On Quantum Droplets, A. Ludu, A.S. Carstea

Publications

Irrotational flow of a spherical thin liquid layer surrounding a rigid core is described using the defocusing nonlinear Schrödinger equation. Accordingly, azimuthal moving nonlinear waves are modeled by periodic dark solitons expressed by elliptic functions. In the quantum regime the algebraic Bethe ansatz is used in order to capture the energy levels of such motions, which we expect to be relevant for the dynamics of the nuclear clusters in deformed heavy nuclei surface modeled by quantum liquid drops. In order to validate the model we match our theoretical energy spectra with experimental results on energy, angular momentum, and parity for …


On Communication For Distributed Babai Point Computation, Maiara F. Bollauf, Vinay A. Vaishampayan, Sueli I.R. Costa Jul 2021

On Communication For Distributed Babai Point Computation, Maiara F. Bollauf, Vinay A. Vaishampayan, Sueli I.R. Costa

Publications and Research

We present a communication-efficient distributed protocol for computing the Babai point, an approximate nearest point for a random vector X∈Rn in a given lattice. We show that the protocol is optimal in the sense that it minimizes the sum rate when the components of X are mutually independent. We then investigate the error probability, i.e. the probability that the Babai point does not coincide with the nearest lattice point, motivated by the fact that for some cases, a distributed algorithm for finding the Babai point is sufficient for finding the nearest lattice point itself. Two different probability models for X …


Learning From The Seed: Illuminating Black Girlhood In Sustainable Living Paradigms, Toni Powell Powell Young Jul 2021

Learning From The Seed: Illuminating Black Girlhood In Sustainable Living Paradigms, Toni Powell Powell Young

USF Tampa Graduate Theses and Dissertations

The contemporary image of sustainable living presents a culturally narrow view of its participants and the manner of engaging in sustainable living paradigms. Through crystallization (Ellingson, 2009) I present a mixed methods approach that emphasizes participant observation, visual, mediated, and discursive analyses, as well as demonstrates the efficacy of Culture Centered Black Feminist Auto/Ethnography. This project seeks to highlight and place within historical context, the ways in which African American girls, who are largely left out of the prevailing image of sustainability, perform and articulate sustainability for themselves, in their homes, and throughout their home communities.

In their everyday lives, …


Augmented Human Machine Intelligence For Distributed Inference, Baocheng Geng Jul 2021

Augmented Human Machine Intelligence For Distributed Inference, Baocheng Geng

Dissertations - ALL

With the advent of the internet of things (IoT) era and the extensive deployment of smart devices and wireless sensor networks (WSNs), interactions of humans and machine data are everywhere. In numerous applications, humans are essential parts in the decision making process, where they may either serve as information sources or act as the final decision makers. For various tasks including detection and classification of targets, detection of outliers, generation of surveillance patterns and interactions between entities, seamless integration of the human and the machine expertise is required where they simultaneously work within the same modeling environment to understand and …


Eccentricity Of Merging Neutron Star Binaries: Searches, Parameter Estimation, And Future Prospects, Amber Kiana Lenon Jul 2021

Eccentricity Of Merging Neutron Star Binaries: Searches, Parameter Estimation, And Future Prospects, Amber Kiana Lenon

Dissertations - ALL

Since the start of the first observing run the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Advanced Virgo observatory have detected 48 binary black hole mergers and two binary neutron star mergers. Knowledge about the properties of the binary can be gained from the gravitational-wave observations. Binary neutron star systems can form with significant orbital eccentricity. Gravitational radiation efficiently removes this eccentricity from the binary's orbit as the star's inspiral together. This thesis describes a search for neutron star binaries that have an eccentric orbits when their gravitational waves enter the sensitive band of Advanced LIGO and Virgo. For …


Odd Annular Bar-Natan Category And Gl(1|1), Casey Necheles Jul 2021

Odd Annular Bar-Natan Category And Gl(1|1), Casey Necheles

Dissertations - ALL

We introduce two monoidal supercategories: the odd dotted Temperley-Lieb category TLo,•(δ), which is a generalization of the odd Temperley-Lieb category studied by Brun-dan and Ellis in [5], and the odd annular Bar-Natan category BNo(A), which generalizes the odd Bar-Natan category studied by Putyra in [16]. We then show there is an equivalence of categories between them if δ=0. We use this equivalence to better understand the action of the Lie superalgebra gl(1|1) on the odd Khovanov homology of a knot in a thickened annulus found by Grigsby and Wehrli in [7].


Evaluating Irrigation Performance And Water Productivity Using Eeflux Et And Ndvi, Usha Poudel, Haroon Stephen, Sajjad Ahmad Jul 2021

Evaluating Irrigation Performance And Water Productivity Using Eeflux Et And Ndvi, Usha Poudel, Haroon Stephen, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Southern California’s Imperial Valley (IV) faces serious water management concerns due to its semi-arid environment, water-intensive crops and limited water supply. Accurate and reliable irrigation system performance and water productivity information is required in order to assess and improve the current water management strategies. This study evaluates the spatially distributed irrigation equity, adequacy and crop water productivity (CWP) for two water-intensive crops, alfalfa and sugar beet, using remotely sensed data and a geographical information system for the 2018/2019 crop growing season. The actual crop evapotranspiration (ETa) was mapped in Google Earth Engine Evapotranspiration Flux, using the linear interpolation method in …


Multi-Modal Self-Supervised Representation Learning For Earth Observation, Pallavi Jain, Bianca Schoen Phelan, Robert J. Ross Jul 2021

Multi-Modal Self-Supervised Representation Learning For Earth Observation, Pallavi Jain, Bianca Schoen Phelan, Robert J. Ross

Conference papers

Self-Supervised learning (SSL) has reduced the performance gap between supervised and unsupervised learning, due to its ability to learn invariant representations. This is a boon to the domains like Earth Observation (EO), where labelled data availability is scarce but unlabelled data is freely available. While Transfer Learning from generic RGB pre-trained models is still common-place in EO, we argue that, it is essential to have good EO domain specific pre-trained model in order to use with downstream tasks with limited labelled data. Hence, we explored the applicability of SSL with multi-modal satellite imagery for downstream tasks. For this we utilised …


New Perspectives On Prolific And Voluminous Rhyolite Volcanism Of The Mahogany Mountain--Three Fingers Rhyolite Field, Eastern Oregon, Robert Andrew Jackson Jul 2021

New Perspectives On Prolific And Voluminous Rhyolite Volcanism Of The Mahogany Mountain--Three Fingers Rhyolite Field, Eastern Oregon, Robert Andrew Jackson

Dissertations and Theses

Voluminous silicic volcanism of the Mahogany Mountain--Three Fingers rhyolite field (MM--TFrf) is spatially and temporally associated with mid-Miocene flood basalts of the Columbia River Basalt province. Early studies of the area advocated for a two-caldera model consisting of the Mahogany Mountain and the slightly younger Three Fingers caldera with pre- and post-caldera effusive rhyolite eruptions. Although close in time, the calderas were thought to be spatially offset producing the tuff of Leslie Gulch and the tuff of Spring Creek. Finding that the tuff of Spring Creek, that is exposed in Leslie Gulch, is an altered product of the tuff of …


Using Quantitative Stereology On High Resolution Sem Images To Estimate Diatom Percentages, Ariadna Covarrubias Ornelas Jul 2021

Using Quantitative Stereology On High Resolution Sem Images To Estimate Diatom Percentages, Ariadna Covarrubias Ornelas

Dissertations and Theses

Diatoms are single-celled organisms of various shapes and sizes typically found in aquatic environments. When diatoms die, the organic material decomposes, and the outer skeletons (i.e., frustules) settle and accumulate as sedimentary deposits. These soils, called diatomaceous soils, exhibit nontraditional behavior since the diatom particles are typically hollow skeletons composed of amorphous silica with intricately patterned and abrasive surfaces. Recent studies have shown that diatomaceous soils are challenging geomaterials since even a small percentage of diatom particles will notably affect engineering behavior. Furthermore, laboratory studies on diatomaceous soil mixtures have demonstrated that many engineering soil properties depend on the percentage …


Real-Time Adaptive Sensor Attack Detection And Recovery In Autonomous Cyber-Physical Systems, Francis Akowuah Jul 2021

Real-Time Adaptive Sensor Attack Detection And Recovery In Autonomous Cyber-Physical Systems, Francis Akowuah

Dissertations - ALL

Cyber-Physical Systems (CPS) tightly couple information technology with physical processes, which rises new vulnerabilities such as physical attacks that are beyond conventional cyber attacks.Attackers may non-invasively compromise sensors and spoof the controller to perform unsafe actions. This issue is even emphasized with the increasing autonomy in CPS. While this fact has motivated many defense mechanisms against sensor attacks, a clear vision of the timing and usability (or the false alarm rate) of attack detection still remains elusive. Existing works tend to pursue an unachievable goal of minimizing the detection delay and false alarm rate at the same time, while there …


Effective Computational Cosmology, Eva Nesbit Jul 2021

Effective Computational Cosmology, Eva Nesbit

Dissertations - ALL

Effective Field Theories (EFTs) provide a unique framework in which to attempt to answer outstanding questions in cosmology (and all field of physics, for that matter). This work investigates how the use of both EFTs and computational tools can help us to advance our knowledge of how the universe evolved and formed over time. Specifically, we review the successful EFT of Inflation, the EFT of Dark Energy (EFTDE), and introduce the EFT of Reheating as a generalized model of particle formation after inflation. In this way, we show how effective EFTs are at quantifying physical phenomenology at many different energy …


Mathematical Optimization Algorithms For Model Compression And Adversarial Learning In Deep Neural Networks, Tianyun Zhang Jul 2021

Mathematical Optimization Algorithms For Model Compression And Adversarial Learning In Deep Neural Networks, Tianyun Zhang

Dissertations - ALL

Large-scale deep neural networks (DNNs) have made breakthroughs in a variety of tasks, such as image recognition, speech recognition and self-driving cars. However, their large model size and computational requirements add a significant burden to state-of-the-art computing systems. Weight pruning is an effective approach to reduce the model size and computational requirements of DNNs. However, prior works in this area are mainly heuristic methods. As a result, the performance of a DNN cannot maintain for a high weight pruning ratio. To mitigate this limitation, we propose a systematic weight pruning framework for DNNs based on mathematical optimization. We first formulate …


Divergent Controls Of Soil Organic Carbon Between Observations And Process-Based Models, Katerina Georgiou, Avni Malhotra, William R. Wieder, Jacqueline H. Ennis, Melannie D. Hartman, Benjamin N. Sulman, Asmeret Asefaw Berhe, A. Stuart Grandy, Emily Kyker-Snowman, Kate Lajtha, Jessica A. M. Moore, Derek Pierson, Robert B. Jackson Jul 2021

Divergent Controls Of Soil Organic Carbon Between Observations And Process-Based Models, Katerina Georgiou, Avni Malhotra, William R. Wieder, Jacqueline H. Ennis, Melannie D. Hartman, Benjamin N. Sulman, Asmeret Asefaw Berhe, A. Stuart Grandy, Emily Kyker-Snowman, Kate Lajtha, Jessica A. M. Moore, Derek Pierson, Robert B. Jackson

Faculty Publications

The storage and cycling of soil organic carbon (SOC) are governed by multiple co-varying factors, including climate, plant productivity, edaphic properties, and disturbance history. Yet, it remains unclear which of these factors are the dominant predictors of observed SOC stocks, globally and within biomes, and how the role of these predictors varies between observations and process-based models. Here we use global observations and an ensemble of soil biogeochemical models to quantify the emergent importance of key state factors – namely, mean annual temperature, net primary productivity, and soil mineralogy – in explaining biome- to global-scale variation in SOC stocks. We …


Field Trials And Long-Term Monitoring Of Microbially-Induced Desaturation For The Treatment Of Liquefiable Silty Soils, Kayla Rae Sorenson Jul 2021

Field Trials And Long-Term Monitoring Of Microbially-Induced Desaturation For The Treatment Of Liquefiable Silty Soils, Kayla Rae Sorenson

Dissertations and Theses

Earthquake liquefaction hazards in silty soils are a critical problem in Portland, Oregon, and other areas around the world. This is a particular problem for existing facilities founded on liquefiable soils, for which there exists no cost-effective liquefaction mitigation solution at the present time. It is essential from both a seismic safety and a seismic resilience perspective to be able to mitigate potentially liquefiable soils underneath existing structures, and to do so in a cost-effective manner. Recent studies suggest that liquefaction mitigation using microbially-induced desaturation (MID) may provide this capability.

The objective of MID is to reduce earthquake-induced excess pore …


Modeling Cyanotoxin Production, Fate And Transport In Surface Waterbodies, Bernadel Rose Hintz Garstecki Jul 2021

Modeling Cyanotoxin Production, Fate And Transport In Surface Waterbodies, Bernadel Rose Hintz Garstecki

Dissertations and Theses

Cyanobacteria exist throughout the world and are frequently associated with forming toxic blooms. The toxins produced by cyanobacteria, cyanotoxins, are harmful to both humans and animals. Rising temperatures due to global climate change, increased nutrient loading, and other anthropogenic impacts on waterbodies are expected to increase the prevalence of cyanobacteria. It is vital that we protect our drinking water supplies and natural water resources. Modeling the production and movement of these toxins is an important step in limiting exposure to them and evaluating management strategies to mitigate their impact. Cyanotoxins are diverse and the conditions under which they are formed …


An Economical Method For Securely Disintegrating Solid-State Drives Using Blenders, Brandon J. Hopkins Phd, Kevin A. Riggle Jul 2021

An Economical Method For Securely Disintegrating Solid-State Drives Using Blenders, Brandon J. Hopkins Phd, Kevin A. Riggle

Journal of Digital Forensics, Security and Law

Pulverizing solid-state drives (SSDs) down to particles no larger than 2 mm is required by the United States National Security Agency (NSA) to ensure the highest level of data security, but commercial disintegrators that achieve this standard are large, heavy, costly, and often difficult to access globally. Here, we present a portable, inexpensive, and accessible method of pulverizing SSDs using a household blender and other readily available materials. We verify this approach by pulverizing SSDs with a variety of household blenders for fixed periods of time and sieve the resulting powder to ensure appropriate particle size. Among the 6 household …


Unlocking The Potential Of Smallholder Livestock Production‐-Using Managed Forages As An Entry Point, W. W. Stür, J. Connell, P. Phengsavanh, T. T. Khanh Jul 2021

Unlocking The Potential Of Smallholder Livestock Production‐-Using Managed Forages As An Entry Point, W. W. Stür, J. Connell, P. Phengsavanh, T. T. Khanh

IGC Proceedings (1993-2023)

No abstract provided.


Biodiversity Of Plants And Animals In Grassland Systems: Approaches To Conservation And Restoration In England, S. Peel, S. P. Chaplin Jul 2021

Biodiversity Of Plants And Animals In Grassland Systems: Approaches To Conservation And Restoration In England, S. Peel, S. P. Chaplin

IGC Proceedings (1993-2023)

No abstract provided.


Recent Initiatives In Biodiversity Conservation In Grazed Temperate Grasslands And Woodlands In Australia, Ian Lunt, John Morgan, Louise Gilfedder, Richard J. Williams, Simon Foster Jul 2021

Recent Initiatives In Biodiversity Conservation In Grazed Temperate Grasslands And Woodlands In Australia, Ian Lunt, John Morgan, Louise Gilfedder, Richard J. Williams, Simon Foster

IGC Proceedings (1993-2023)

No abstract provided.


Aromatic Substitution: Another View, Charles A. Kingsbury Jul 2021

Aromatic Substitution: Another View, Charles A. Kingsbury

Chemistry Department: Faculty Publications

Electrophilic substitution on substituted benzenes is reviewed in terms of molecular orbitals. The HOMO falls into two classes. For all meta director C-X groups, a node passes through the ring and through the substituent C-X bond. With ortho/para director C-X groups, a node perpendicular to the one described above, passes through the ortho-meta bonds.


Multiple Baseline Interrupted Time Series: Describing Changes In New Mexico Medicaid Behavioral Health Home Patients’ Care, Jessica Reno Jul 2021

Multiple Baseline Interrupted Time Series: Describing Changes In New Mexico Medicaid Behavioral Health Home Patients’ Care, Jessica Reno

Mathematics & Statistics ETDs

In 2016, the CareLink New Mexico behavioral health homes program began enrolling Medicaid recipients with the goal of increasing care coordination, improving access to services, and decreasing long-term costs of care for adults with serious mental illness (SMI) and children with severe emotional disturbance (SED). To evaluate these aims, a retrospective interrupted time series study using Medicaid claims data was designed. First, a comparable subset of non-enrolled individuals was selected from the pool of Medicaid recipients with SMI or SED using propensity score matching. Then, segmented regression was applied to three outcomes: total Medicaid charges, number of outpatient behavioral health …


Learning To Learn Variational Semantic Memory, Xiantong Zhen, Yingjun Du, Huan Xiong, Cees G.M. Snoek, Ling Shao Jul 2021

Learning To Learn Variational Semantic Memory, Xiantong Zhen, Yingjun Du, Huan Xiong, Cees G.M. Snoek, Ling Shao

Machine Learning Faculty Publications

In this paper, we introduce variational semantic memory into meta-learning to acquire long-term knowledge for few-shot learning. The variational semantic memory accrues and stores semantic information for the probabilistic inference of class prototypes in a hierarchical Bayesian framework. The semantic memory is grown from scratch and gradually consolidated by absorbing information from tasks it experiences. By doing so, it is able to accumulate long-term, general knowledge that enables it to learn new concepts of objects. We formulate memory recall as the variational inference of a latent memory variable from addressed contents, which offers a principled way to adapt the knowledge …


Net Geochemical Release Of Base Cations From 25 Forested Watersheds In The Catskill Region Of New York, Sara C. Nieman, Chris E. Johnson Jul 2021

Net Geochemical Release Of Base Cations From 25 Forested Watersheds In The Catskill Region Of New York, Sara C. Nieman, Chris E. Johnson

Civil and Environmental Engineering

Chemical weathering of minerals is the principal mechanism by which base cations (Ca2+, Mg2+, K+, and Na+) are released and acidity is neutralized in soils, bedrock and drainage waters. Quantifying the release of base cations from watershed soils is therefore crucial for the calculation of “critical loads” of atmospheric acidity to forest ecosystems. We used a mass-balance approach to estimate the rate of release of base cations in 25 headwater catchments in the Catskill region of New York, an area historically subject to high inputs of acid deposition. In 2010-2013, total net …


Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci Jul 2021

Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci

Earth and Planetary Sciences ETDs

Melting and differentiation are fundamental to early solar system evolution on planetary bodies that accreted enough material to heat up radioactively or through impacts and breach their solidi. Partially and fully melted material is present in the meteorite record in the form of primitive achondrites and achondrites, which are fragments of planetesimals that underwent heating events in the first few million years of solar system history. Although the vast majority of this material is mafic or ultramafic, new evolved samples, recovered in the last few decades, are pushing the petrologic and geochemical boundaries of planetesimal melting, differentiation, and crust formation. …


Upper Limits On The Isotropic Gravitational-Wave Background From Advanced Ligo And Advanced Virgo's Third Observing Run, R. Abbott, T. D. Abbott, S. Abraham, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Jul 2021

Upper Limits On The Isotropic Gravitational-Wave Background From Advanced Ligo And Advanced Virgo's Third Observing Run, R. Abbott, T. D. Abbott, S. Abraham, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report results of a search for an isotropic gravitational-wave background (GWB) using data from Advanced LIGO's and Advanced Virgo's third observing run (O3) combined with upper limits from the earlier O1 and O2 runs. Unlike in previous observing runs in the advanced detector era, we include Virgo in the search for the GWB. The results of the search are consistent with uncorrelated noise, and therefore we place upper limits on the strength of the GWB. We find that the dimensionless energy density ΩGW ≤ 5.8 x 10-9 at the 95% credible level for a flat (frequency-independent) GWB, …


Stereocontrolled Mannosylation By Hydrogen-Bond-Mediated Aglycone Delivery, Catherine Alex Jul 2021

Stereocontrolled Mannosylation By Hydrogen-Bond-Mediated Aglycone Delivery, Catherine Alex

Dissertations

Stereocontrolled Mannosylation by Hydrogen-Bond-Mediated Aglycone Delivery

Carbohydrates are the essential bio-molecules of life as they form the forefront of interactions with receptors, proteins, pathogens, or neighboring cells. On cell-surfaces, carbohydrates are mostly found as linear or branched glycoconjugates, and a majority of them are linked via either 1,2-cis or 1,2-trans O-glycosidic linkages. There is no template-driven pathway for achieving the synthesis of glycans unlike other biomolecules like proteins and nucleic acids. The synthesis of 1,2-trans glycosides can be reliably achieved via the neighboring group assistance. The synthesis of 1,2-cis glycosides is difficult because, beyond weak anomeric effects, there are …


Enrolling Reactive Oxygen Species In Photon-To-Chemical Energy Conversion: Fundamentals, Technological Advances, And Applications, Irving D. Rettig, Theresa M. Mccormick Jul 2021

Enrolling Reactive Oxygen Species In Photon-To-Chemical Energy Conversion: Fundamentals, Technological Advances, And Applications, Irving D. Rettig, Theresa M. Mccormick

Chemistry Faculty Publications and Presentations

In theory, oxygen (O2) is an ideal chemical reagent because of its high relative abundance and negligible environmental toxicity. In practice however, by the nature of its ground state electronic configuration, many chemical reactions involving O2 are spin forbidden which dramatically decreases its reactivity and thus its utility in applications. More reactive forms of O2 can be achieved by changing its electronic configuration through the use of photochemical and photophysical methods. This review highlights the roll of photon-to-chemical energy conversion in two of these reactive oxygen species (ROS): superoxide (O2−) and singlet oxygen (1O2), which can be accessed through a …