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Articles 601 - 630 of 7340

Full-Text Articles in Physical Sciences and Mathematics

Simulating The Storm Environment Responsible For Nepal's First Observed Tornado, Jonathan David Douglas Meyer, Binod Pokharel, Robert R. Gillies Aug 2021

Simulating The Storm Environment Responsible For Nepal's First Observed Tornado, Jonathan David Douglas Meyer, Binod Pokharel, Robert R. Gillies

Plants, Soils, and Climate Faculty Publications

A high-resolution numerical forecast model was used to simulate the meteorological conditions leading up to the March 31st, 2019 severe weather event that produced Nepal's first-ever observed tornado. The sparse meteorologic observations in the region capturing the storm environment limit the ability to anticipate another similar situation should the particular set of conditions present themselves again. This study presents a multifaced view of the storm environment through 1) a synoptic perspective provided by the Global Data Assimilation System (GDAS) reanalysis dataset and 2) a trio of progressively higher resolution one-way nested simulations (12 km–4km–1km) driven by GDAS boundary conditions to …


Temperature Tides Across The Mid-Latitude Summer Turbopause Measured By A Sodium Lidar And Mighti/Icon, Tao Yuan, M. H. Stevens, C. R. Englert, T. J. Immel Aug 2021

Temperature Tides Across The Mid-Latitude Summer Turbopause Measured By A Sodium Lidar And Mighti/Icon, Tao Yuan, M. H. Stevens, C. R. Englert, T. J. Immel

All Physics Faculty Publications

Local full diurnal coverage of temperature variations across the turbopause (∼90–115 km altitude) is achieved by combining the nocturnal observations of a Sodium (Na) Doppler lidar on the Utah State University (USU) campus (41.7°N, 248.2°E) and NASA Michelson interferometer for global high-resolution thermospheric imaging (MIGHTI)/Ionospheric connection explorer (ICON) daytime observations made in the same vicinity. In this study, utilizing this hybrid data set during summer 2020 between June 12th and July 15th, we retrieve the temperature signatures of diurnal and semidiurnal tides in this region. The tidal amplitudes of both components have similar vertical variation with increasing altitude: less than …


Nickel Catalyzed Electrochemical C-C Cross-Coupling Reactions, T. Leo Liu Aug 2021

Nickel Catalyzed Electrochemical C-C Cross-Coupling Reactions, T. Leo Liu

Funded Research Records

No abstract provided.


Moderate Plant–Soil Feedbacks Have Small Effects On The Biodiversity–Productivity Relationship: A Field Experiment, Josephine Grenzer, Andrew Kulmatiski, Leslie Forero, Anne Ebeling, Nico Eisenhauer, Jeanette Norton Aug 2021

Moderate Plant–Soil Feedbacks Have Small Effects On The Biodiversity–Productivity Relationship: A Field Experiment, Josephine Grenzer, Andrew Kulmatiski, Leslie Forero, Anne Ebeling, Nico Eisenhauer, Jeanette Norton

Wildland Resources Student Research

Plant–soil feedback (PSF) has gained attention as a mechanism promoting plant growth and coexistence. However, most PSF research has measured monoculture growth in greenhouse conditions. Translating PSFs into effects on plant growth in field communities remains an important frontier for PSF research. Using a 4-year, factorial field experiment in Jena, Germany, we measured the growth of nine grassland species on soils conditioned by each of the target species (i.e., 72 PSFs). Plant community models were parameterized with or without these PSF effects, and model predictions were compared to plant biomass production in diversity–productivity experiments. Plants created soils that changed subsequent …


Physics-Informed Structure-Preserving Numerical Approximations Of Thermodynamically Consistent Models For Non-Equilibrium Phenomena, Jia Zhao Aug 2021

Physics-Informed Structure-Preserving Numerical Approximations Of Thermodynamically Consistent Models For Non-Equilibrium Phenomena, Jia Zhao

Funded Research Records

No abstract provided.


Attribution Of Responsibility After Failures Within Platform Ecosystems, Brian Dunn, Matthew L. Jensen, Ryan Ralston Aug 2021

Attribution Of Responsibility After Failures Within Platform Ecosystems, Brian Dunn, Matthew L. Jensen, Ryan Ralston

Data Analytics & Information Systems Faculty Publications

Increasingly, new hardware and software are embedded within ecosystems that include a platform and modules. Ideally these ecosystems perform reliably. However, if an ambiguously sourced failure occurs within one of these ecosystems, users are left to distribute blame across the various components of the ecosystem. The actual distribution of this blame, however, can be difficult to predict. This study investigates attribution of blame and discontinuance recommendations for ecosystem components after an ambiguously sourced failure. To extend platform ecosystems and attribution theory, we conducted a scenario-based experiment investigating the negative consequences of failure for platform and module components and the contingent …


Interactions Between Humans, Crocodiles, And Hippos At Lake Kariba, Zimbabwe, Ivan Marowa, Joshua Matanzima, Tamuka Nhiwatiwa Aug 2021

Interactions Between Humans, Crocodiles, And Hippos At Lake Kariba, Zimbabwe, Ivan Marowa, Joshua Matanzima, Tamuka Nhiwatiwa

Human–Wildlife Interactions

Human–wildlife conflicts (HWCs) are on the increase due to shrinking space that results in increased competition for land, water, and other natural resources between humans and wildlife. Investigating the occurrence of HWCs is important in that the results can be used to formulate better management policies and strategies. In this paper, we describe the nature of HWCs emerging between humans and the Nile crocodile (Crocodylus niloticus) and between humans and the African hippopotamus (Hippopotamus amphibius; hippo) on Lake Kariba, Zimbabwe. Lake Kariba is the second largest manmade lake by volume in the world. Conflicts involving humans …


Compounding Hazards And Intersecting Vulnerabilities: Experiences And Responses To Extreme Heat During Covid-19, Olga V. Wilhelmi, Peter D. Howe, Mary H. Hayden, Cassandra R. O'Lenick Aug 2021

Compounding Hazards And Intersecting Vulnerabilities: Experiences And Responses To Extreme Heat During Covid-19, Olga V. Wilhelmi, Peter D. Howe, Mary H. Hayden, Cassandra R. O'Lenick

Environment and Society Faculty Publications

Extreme heat is a major threat to human health worldwide. The COVID-19 pandemic, with its complexity and global reach, created unprecedented challenges for public health and highlighted societal vulnerability to hazardous hot weather. In this study, we used data from a three-wave nationally representative survey of 3036 American adults to examine how the COVID-19 pandemic affected extreme heat vulnerability during the summer of 2020. We used mixed effects models to examine the roles of socio-demographic characteristics and pandemic-related factors in the distribution of negative heat effects and experiences across the United States. The survey findings show that over a quarter …


Collaborative Research: Deciphering The Role Of Extreme Rainstorms And Hydroclimatic Regime On Arid Escarpment Retreat And Sub-Cliff Slope Evolution, Joel Pederson Aug 2021

Collaborative Research: Deciphering The Role Of Extreme Rainstorms And Hydroclimatic Regime On Arid Escarpment Retreat And Sub-Cliff Slope Evolution, Joel Pederson

Funded Research Records

No abstract provided.


Benchmarking Nimrod Continuum Kinetic Formulations Through The Steady-State Poloidal Flow, Joseph R. Jepson, Chris C. Hegna, Eric D. Held, J. Andrew Spencer, B. C. Lyons Aug 2021

Benchmarking Nimrod Continuum Kinetic Formulations Through The Steady-State Poloidal Flow, Joseph R. Jepson, Chris C. Hegna, Eric D. Held, J. Andrew Spencer, B. C. Lyons

All Physics Faculty Publications

In this work, continuum kinetic formulations are employed as a mechanism to include closure physics in an extended magnetohydrodynamics model. Two continuum kinetic approaches have been implemented in the plasma fluid code NIMROD [Sovinec et al., “Nonlinear magnetohydrodynamics with high-order finite elements,” J. Comput. Phys. 195, 355 (2004)] including a Chapman–Enskog-like (CEL) formulation and a more conventional δf approach. Ion kinetic closure schemes are employed to describe the neoclassical flow properties in axisymmetric toroidal geometry. In particular, predictions for steady-state values of poloidal flow profiles in tokamak geometry are provided using both the δf formulation and two different solution …


Computational Frontiers In The Strong Gravity Regime, Maria Rodriguez Aug 2021

Computational Frontiers In The Strong Gravity Regime, Maria Rodriguez

Funded Research Records

No abstract provided.


Understanding The Effects Of Climate Change Via Disturbance On Pristine Arctic Lakes—Multitrophic Level Response And Recovery To A 12-Yr, Low-Level Fertilization Experiment, Phaedra Budy, Casey A. Pennock, Anne E. Giblin, Chris Luecke, Daniel L. White, George W. Kling Aug 2021

Understanding The Effects Of Climate Change Via Disturbance On Pristine Arctic Lakes—Multitrophic Level Response And Recovery To A 12-Yr, Low-Level Fertilization Experiment, Phaedra Budy, Casey A. Pennock, Anne E. Giblin, Chris Luecke, Daniel L. White, George W. Kling

Watershed Sciences Student Research

Effects of climate change-driven disturbance on lake ecosystems can be subtle; indirect effects include increased nutrient loading that could impact ecosystem function. We designed a low-level fertilization experiment to mimic persistent, climate change-driven disturbances (deeper thaw, greater weathering, or thermokarst failure) delivering nutrients to arctic lakes. We measured responses of pelagic trophic levels over 12 yr in a fertilized deep lake with fish and a shallow fishless lake, compared to paired reference lakes, and monitored recovery for 6 yr. Relative to prefertilization in the deep lake, we observed a maximum pelagic response in chl a (+201%), dissolved oxygen (DO, −43%), …


Human Appropriation Of Net Primary Production: From A Planet To A Pixel, Suman Paudel, Gustavo A. Ovando-Montejo, Christopher L. Lant Aug 2021

Human Appropriation Of Net Primary Production: From A Planet To A Pixel, Suman Paudel, Gustavo A. Ovando-Montejo, Christopher L. Lant

UAES Publications

Human appropriation of net primary production (HANPP) is a substantial improvement upon 20th century attempts at developing an ecological footprint indicator because of its measurability in relation to net primary production, its close relationship to other key footprint measures, such as carbon and water, and its spatial specificity. This paper explores HANPP across four geographical scales: through literature review, the planet; through reanalysis of existing data, variations among the world’s countries; and through novel analyses, U.S. counties and the 30 m pixel scale for one U.S. county. Results show that HANPP informs different sustainability narratives at different scales. At the …


Mathematical Models And Homogenization Of Deer Dispersal, Environmental Hazard, And Direct/Indirect Transmission To Predict Spread Of Chronic Wasting Disease, James A. Powell Aug 2021

Mathematical Models And Homogenization Of Deer Dispersal, Environmental Hazard, And Direct/Indirect Transmission To Predict Spread Of Chronic Wasting Disease, James A. Powell

Funded Research Records

No abstract provided.


Cross-Boundary Weed Management In Protected Area-Centered Ecosystems: How Can It Work And What Makes It Harder To Achieve?, Natalie Otto, Mark W. Brunson Aug 2021

Cross-Boundary Weed Management In Protected Area-Centered Ecosystems: How Can It Work And What Makes It Harder To Achieve?, Natalie Otto, Mark W. Brunson

Environment and Society Student Research

Invasive species management in natural landscapes is generally executed at the scale of independent jurisdictions, yet the ecological processes and biodiversity to be protected from invasion occur over large spatial scales and across multiple jurisdictions. Jurisdictional land boundaries can influence the flows and dynamics of ecological systems, as well as the social systems that exist in these complex landscapes. Land management entities in large, protected area-centered ecosystems may use different approaches to address cross-boundary management challenges. To understand these differing strategies and their effects on cooperative invasive plant management, we interviewed employees with federal, county and state agencies, research organizations, …


Exploring Questions Of Tectonic Geomorphology In The Bear River Range, Utah Using Terrain Analysis And Reconstruction, Edward M. Grasinger Aug 2021

Exploring Questions Of Tectonic Geomorphology In The Bear River Range, Utah Using Terrain Analysis And Reconstruction, Edward M. Grasinger

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Despite a long tradition of geologic studies in the region surrounding Utah State University, there remain unexplored questions and unutilized approaches for understanding the landscape evolution of the Bear River Range. A large-scale reconstruction of the East Cache fault system can be useful in estimating the total displacement of the fault, its geologic longevity, and total energy involved. Likewise, an analysis of reach-scale features of the Logan River can explore how tectonics and bedrock type affect the patterns and history of the river. Geographic Information Systems (GIS) software is useful in reconstructing, visualizing, and measuring such geomorphological features and changes …


Comparative Study Of Machine Learning Models On Solar Flare Prediction Problem, Nikhil Sai Kurivella Aug 2021

Comparative Study Of Machine Learning Models On Solar Flare Prediction Problem, Nikhil Sai Kurivella

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar flare events are explosions of energy and radiation from the Sun’s surface. These events occur due to the tangling and twisting of magnetic fields associated with sunspots. When Coronal Mass ejections accompany solar flares, solar storms could travel towards earth at very high speeds, disrupting all earthly technologies and posing radiation hazards to astronauts. For this reason, the prediction of solar flares has become a crucial aspect of forecasting space weather. Our thesis utilized the time-series data consisting of active solar region magnetic field parameters acquired from SDO that span more than eight years. The classification models take AR …


Report: Spatial Facilitation-Inhibition Effects On Vegetation Distribution And Their Associated Patterns, Daniel D'Alessio Aug 2021

Report: Spatial Facilitation-Inhibition Effects On Vegetation Distribution And Their Associated Patterns, Daniel D'Alessio

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Changes in the spatial distribution of vegetation respond to variations in the production and transportation mechanisms of seeds at different locations subject to heterogeneities, often because of soil characteristics. In semi-arid environments, the competition for water and nutrients pushes the superficial plant’s roots to obtain scarce resources at long ranges. In this report, we assume that vegetation biomass interacts with itself in two different ways, facilitation and inhibition, depending on the relative distances. We present a 1-dimensional Integro-difference model to represent and study the emergence of patterns in the distribution of vegetation.


Using Unmanned Aerial Vehicles To Quantify Erosion Control Measures On A Reclaimed Central Utah Coal Mine, Christopher R. Brown Aug 2021

Using Unmanned Aerial Vehicles To Quantify Erosion Control Measures On A Reclaimed Central Utah Coal Mine, Christopher R. Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For certain landscape reclamation efforts surrounding, the Utah Division of Oil Gas and Mining (UDOGM) utilizes a surface roughing technique called “pocking”. The process of pocking establishes closely spaced gouges approximately 1.2 meters in diameter and 0.5 meters deep across a reclaimed landscape in order to reduce surface erosion and promote plant growth on steep terrain in arid regions. Pocks are designed as a series of micro watersheds that trap water to aid in plant establishment and reduces overland flow of water. Over time vegetation grows within the pocks as they infill with sediment. While this method is considered an …


It Isn't Easy Speaking Green: The Influence Of Moral Factors On The (Non-) Adoption Of Pro-Environmental Behaviors, Deferral, And Back Again, Alexi Elizabeth Lamm Aug 2021

It Isn't Easy Speaking Green: The Influence Of Moral Factors On The (Non-) Adoption Of Pro-Environmental Behaviors, Deferral, And Back Again, Alexi Elizabeth Lamm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change is one of the major issues humans face in the 21st century. This decade is critical in shaping the future of Earth and the way humans live on it (IPCC, 2018). Changes in human behavior are necessary to mitigate and adapt to climate change. This series of studies explored factors important in communicating and implementing environmental behavior. The first study tested the effects of an online, interactive carbon calculator with moral interventions on three self-reported measures and one objective measure of behavior over a period of weeks. The interventions resulted in small changes in self-reported behavior and …


Backcountry Campsite Environmental Changes And Effective Monitoring Practices: A Case Study In Kenai Fjords National Park, Shannon T. Wesstrom, Christopher Monz Aug 2021

Backcountry Campsite Environmental Changes And Effective Monitoring Practices: A Case Study In Kenai Fjords National Park, Shannon T. Wesstrom, Christopher Monz

Environment and Society Student Research

This report examines existing backcountry campsites’ resource conditions over a five-year period in Kenai Fjords National Park (KEFJ), Alaska. Using campsite ecological monitoring techniques, 101 campsites were assessed for area size, vegetation cover loss, condition class assessments, as well as other indicator variable measurements. This research utilized parametric, non-parametric, robust linear regression, and principal component analysis statistical approaches to inform park managers of:

  • Spatial and temporal patterns in changing campsite ecological variable conditions.
  • Predicted annual variability of each ecological variable by campsite, beach, and bay.
  • Opportunities for possible improvements in the efficiency of the current monitoring protocol by identifying:
    • An …


Wildland Fire Risk Perceptions And Mitigation Actions In The Western United States: A Systematic Literature Review And Two Empirical Case Studies, Lauren Nicole-Dupéy Larsen Aug 2021

Wildland Fire Risk Perceptions And Mitigation Actions In The Western United States: A Systematic Literature Review And Two Empirical Case Studies, Lauren Nicole-Dupéy Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Individuals are continuing to move into previously uninhabited, wildlands in the Western United States where fire danger is often high. This continued movement of people is a two-fold problem. First, individuals are moving into areas that have dense forestland and other flammable vegetation types where wildfires can easily ignite and spread. Second, individuals are starting more wildfires in these previously uninhabited areas (over 90% of wildfires across the country are caused by humans). Although wildfire is a complex topic, one thing is simple: As individuals continue to move into these wild, forested, and often mountainous areas, the risk of these …


Housing Variables And Immigration: An Exploratory And Predictive Data Analysis In New York City, Jhonatan Medri Cobos Aug 2021

Housing Variables And Immigration: An Exploratory And Predictive Data Analysis In New York City, Jhonatan Medri Cobos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationship between housing and immigration has become relevant in the U.S., especially in a highly populated metropolis such as New York City (NYC). Determining whether immigration status affects home ownership percentage, household rent, or housing cost percentage could help understand the quality of life of NYC residents. Graphical exploration, spatial dependence tests, and spatial autoregressive models of housing and immigration variables provide some insights about their relationships. Our exploration takes place at some geographic subareas of NYC.

Our results first indicate that the housing and immigration data reports spatial dependence; values of a geographic subarea are related to values …


Deep Learning Data And Indexes In A Database, Vishal Sharma Aug 2021

Deep Learning Data And Indexes In A Database, Vishal Sharma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A database is used to store and retrieve data, which is a critical component for any software application. Databases requires configuration for efficiency, however, there are tens of configuration parameters. It is a challenging task to manually configure a database. Furthermore, a database must be reconfigured on a regular basis to keep up with newer data and workload. The goal of this thesis is to use the query workload history to autonomously configure the database and improve its performance. We achieve proposed work in four stages: (i) we develop an index recommender using deep reinforcement learning for a standalone database. …


Fixed Pattern Noise Non-Uniformity Correction Through K-Means Clustering, Andres Imperial Aug 2021

Fixed Pattern Noise Non-Uniformity Correction Through K-Means Clustering, Andres Imperial

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Imagery obtained with poorly calibrated sensors is often corrupted with fixed pattern noise. Fixed pattern noise presents itself through a non-uniform distribution and therefore is hard to target in noise removal. Traditional noise removal techniques assume that the noise is uniformly distributed and subsequently produces inadequate corrections. Noise correction methods that target fixed pattern noise rely on dynamically identifying present noise and adjust correction values appropriately using nearby information or general assumptions about the image’s composition. If noise identification is not accurate, the correction values will also suffer from low accuracy. Inaccurate correction values can affect the imagery’s quality, and …


Breast Ultrasound Image Segmentation Based On Uncertainty Reduction And Context Information, Kuan Huang Aug 2021

Breast Ultrasound Image Segmentation Based On Uncertainty Reduction And Context Information, Kuan Huang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Breast cancer frequently occurs in women over the world. It was one of the most serious diseases and the second common cancer among women in 2019. The survival rate of stages 0 and 1 of breast cancer is closed to 100%. It is urgent to develop an approach that can detect breast cancer in the early stages. Breast ultrasound (BUS) imaging is low-cost, portable, and effective; therefore, it becomes the most crucial approach for breast cancer diagnosis. However, BUS images are of poor quality, low contrast, and uncertain. The computer-aided diagnosis (CAD) system is developed for breast cancer to prevent …


Multi-Proxy Approach To Robustly Capture Earthquake Temperature Rise At The Punchbowl Fault, California, Emma M. Armstrong Aug 2021

Multi-Proxy Approach To Robustly Capture Earthquake Temperature Rise At The Punchbowl Fault, California, Emma M. Armstrong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Earthquakes produce heat along a fault surface from friction created as two blocks of rock move past each other. The amount of heat generated depends on a variety of factors, including rock type, stresses, and thickness of the fault zone. Identifying evidence for and quantifying this earthquake (coseismic) temperature rise are essential for identifying past earthquakes in the rock record. Indirect methods, such as textures and geochemical signatures that change with temperature, can serve as paleothermometers. Here we compare two paleothermometers, biomarkers and thermochronometry, from two transects across the Punchbowl fault (PF), California. The PF is an ancient fault strand …


Logbert: Log Anomaly Detection Via Bert, Haixuan Guo Aug 2021

Logbert: Log Anomaly Detection Via Bert, Haixuan Guo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When systems break down, administrators usually check the produced logs to diagnose the failures. Nowadays, systems grow larger and more complicated. It is labor-intensive to manually detect abnormal behaviors in logs. Therefore, it is necessary to develop an automated anomaly detection on system logs. Automated anomaly detection not only identifies malicious patterns promptly but also requires no prior domain knowledge. Many existing log anomaly detection approaches apply natural language models such as Recurrent Neural Network (RNN) to log analysis since both are based on sequential data. The proposed model, LogBERT, a BERT-based neural network, can capture the contextual information in …


Algorithms For Covering Barrier Points By Mobile Sensors With Line Constraint, Princy Jain Aug 2021

Algorithms For Covering Barrier Points By Mobile Sensors With Line Constraint, Princy Jain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this thesis, we develop efficient algorithms for the problem of covering barrier points by mobile sensors. Each sensor is represented by a point in the plane with the same covering range r so that any point within distance r from the sensor can be covered by the sensor. Given a set B of m points (called “barrier points”) and a set S of n points (representing the “sensors”) in the plane, the problem is to move the sensors so that each barrier point is covered by at least one sensor and the maximum movement of all sensors is minimized. …


Foliar Photodegradation In Pesticide Environmental Modeling, Sean M. Lyons Aug 2021

Foliar Photodegradation In Pesticide Environmental Modeling, Sean M. Lyons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work described here was conducted to better understand how pesticides will behave following their application to crops or soil. This understanding will allow for better use of pesticides which will protect the environment and non-target organisms while remaining effective against pests. The Pesticide Dissipation form Agricultural Land (PeDAL) model was developed to simulate pesticide behavior following application and laboratory experiments focused on the photodegradation of select pesticides on alfalfa leaves were conducted to support this model.