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2022

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Articles 17221 - 17250 of 18302

Full-Text Articles in Physical Sciences and Mathematics

Comparison Of Volatile Chemical Components Of Cystoseira Crinita Duby By Hydrodistillation(Hd) And Solid-Phase Microextraction (Spme) Methods And Antimicrobialand Scolicidal Activities Of Essential Oil And Extracts, Tayyi̇be Beyza Yücel Jan 2022

Comparison Of Volatile Chemical Components Of Cystoseira Crinita Duby By Hydrodistillation(Hd) And Solid-Phase Microextraction (Spme) Methods And Antimicrobialand Scolicidal Activities Of Essential Oil And Extracts, Tayyi̇be Beyza Yücel

Turkish Journal of Chemistry

This study aims to derive an essential oil from Cystoseira crinita Duby, analyze the chemical composition of the essential oil, discover the antimicrobial activities of the oil and the extracts, and investigate the scolicidal activities of the extracts. The volatile organic compounds of Cystoseira crinita Duby were determined by GC/MS-FID using both hydro-distillation (HD) and solid-phase microextraction (SPME) methods. As a result of the essential oil analysis, 97.14% of 17 compounds and 93.13% of 19 compounds were elucidated. The main compounds identified were hexanal (31.802%), n-hexadecanoic acid (12.654%), trans-β-ionone (9.118%), 2E-hexenal (15.955%), heptadecane (15.729%) and tetradecane (13.458%). In addition, hexane, …


Facial Landmark Feature Fusion In Transfer Learning Of Child Facial Expressions, Megan A. Witherow, Manar D. Samad, Norou Diawara, Khan M. Iftekharuddin Jan 2022

Facial Landmark Feature Fusion In Transfer Learning Of Child Facial Expressions, Megan A. Witherow, Manar D. Samad, Norou Diawara, Khan M. Iftekharuddin

Electrical & Computer Engineering Faculty Publications

Automatic classification of child facial expressions is challenging due to the scarcity of image samples with annotations. Transfer learning of deep convolutional neural networks (CNNs), pretrained on adult facial expressions, can be effectively finetuned for child facial expression classification using limited facial images of children. Recent work inspired by facial age estimation and age-invariant face recognition proposes a fusion of facial landmark features with deep representation learning to augment facial expression classification performance. We hypothesize that deep transfer learning of child facial expressions may also benefit from fusing facial landmark features. Our proposed model architecture integrates two input branches: a …


Momentum Of Light In Complex Media, Yuri Obukhov Jan 2022

Momentum Of Light In Complex Media, Yuri Obukhov

Turkish Journal of Physics

An important issue in phenomenological macroscopic electrodynamics of moving media is the definition of the energy and momentum of the electromagnetic field in matter. Rather surprisingly, this topic has demonstrated a remarkable longevity, and the problem of the electromagnetic energy and momentum in matter remained open, despite numerous theoretical and experimental investigations. We overview the definition of the momentum of light in matter and demonstrate that, for the correct understanding of the problem, one needs to carefully distinguish situations when the material medium is modeled either as a background for light or as a dynamical part of the total system. …


Investigating The Potential Of Laser-Written One-Dimensional Photonic Crystals Inside Silicon, Onur Tokel Jan 2022

Investigating The Potential Of Laser-Written One-Dimensional Photonic Crystals Inside Silicon, Onur Tokel

Turkish Journal of Physics

The field of silicon photonics is based on introducing and exploiting advanced optical functionality. Current efforts in the field are based on conventional micro/nanofabrication methods, leading to optical functionality over wafer surfaces. A complementary and emerging field is introducing analogous optics directly within the wafer using lasers. Here we investigate the theoretical feasibility of a subclass of such optics, photonic crystals. Our efforts will guide future experimental efforts towards in-chip spectral control.


On An Econophysics Model, Miron Kaufman Jan 2022

On An Econophysics Model, Miron Kaufman

Turkish Journal of Physics

Krugman has proposed a continuous in time and space model for the emergence of polycentric urban areas in the regional space. By using a discrete version of this model on spatial networks, we predicted the distribution of jobs among the different localities inside a couple of economic regions in Ohio and Texas. The time evolution of the distribution of jobs is governed by a market potential. Employment gradually moves towards locations considered relatively attractive if their market potential is above the spatial average. Similarly, jobs move away from locations with below-average market potential. First, I will show that the market …


Geodesics Of Fiberwise Cigar Soliton Deformation Of The Sasaki Metric, Liana Lotarets Jan 2022

Geodesics Of Fiberwise Cigar Soliton Deformation Of The Sasaki Metric, Liana Lotarets

Turkish Journal of Mathematics

Ricci solitons arose in proof the Poincare conjecture by R. Hamilton and G. Perelman. The first example of a noncompact steady Ricci soliton on a plane was found by R. Hamilton. This two-dimensional manifold is conformally equivalent to the plane and it is called by R. Hamilton's cigar soliton. The cigar soliton metric can be considered as a fiber-wise conformal deformation of the Euclidean metric on a fiber of the tangent bundle. In the paper we propose a deformation of the classical Sasaki metric on the tangent bundle of an n-dimensional Riemannian manifold that induces the cigar soliton type metric …


A Variant Of Rosset's Approach To The Amitsur-Levitzki Theorem And Some $\Mathbb{Z}_{2}$-Graded Identities Of $\Mathrm{M}_{N}(E)$, Szilvia Homolya, Jen Szigeti Jan 2022

A Variant Of Rosset's Approach To The Amitsur-Levitzki Theorem And Some $\Mathbb{Z}_{2}$-Graded Identities Of $\Mathrm{M}_{N}(E)$, Szilvia Homolya, Jen Szigeti

Turkish Journal of Mathematics

In the spirit of Rosset's proof of the Amitsur-Levitzki theorem, we show how the standard identiy (for matrices over a commutative base ring) and the addition of external Grassmann variables can be used to derive a certain $\mathbb{Z}_{2}$-graded polynomial identity of $\mathrm{M}_{n}(E)$.


Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland, Daniel J. Emmons, Robert D. Loper Jan 2022

Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland, Daniel J. Emmons, Robert D. Loper

Faculty Publications

Forecasting of solar flares remains a challenge due to the limited understanding of the triggering mechanisms associated with magnetic reconnection, the primary physical phenomenon connected to these events. Studies have indicated that changes to the photospheric magnetic fields associated with magnetic reconnection – particularly in relation to the field helicity – occur during solar flare events. This study utilized data from the Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager (HMI) and SpaceWeather HMI Active Region Patches (SHARPs) to analyze full vector-field component data of the photospheric magnetic field during solar flare events within a near decade long HMI dataset. …


Pathways Forward For Onshore Wind Energy In The State Of Maryland: A Gis Multi-Criteria Analysis, George Pisano Jan 2022

Pathways Forward For Onshore Wind Energy In The State Of Maryland: A Gis Multi-Criteria Analysis, George Pisano

Geography and the Environment: Graduate Student Capstones

This study examines pathways forward for onshore wind energy in the State of Maryland. To meet its decarbonization goals, Maryland needs to quickly transition its electric grid away from fossil fuels. The state is currently in the process of developing offshore wind farms that have the potential to represent a significant source of renewable energy. However little progress has been made in expanding Maryland’s onshore wind energy production capacity. Using a multi-criteria GIS analysis, this study found that there is a limited but not inconsiderable area in the state that could be suitable for wind farms of varying scales that …


An Integrated Computational Pipeline To Construct Patient-Specific Cancer Models, Daniel Plaugher Jan 2022

An Integrated Computational Pipeline To Construct Patient-Specific Cancer Models, Daniel Plaugher

Theses and Dissertations--Mathematics

Precision oncology largely involves tumor genomics to guide therapy protocols. Yet, it is well known that many commonly mutated genes cannot be easily targeted. Even when genes can be targeted, resistance to therapy is quite common. A rising field with promising results is that of mathematical biology, where in silico models are often used for the discovery of general principles and novel hypotheses that can guide the development of new treatments. A major goal is that eventually in silico models will accurately predict clinically relevant endpoints and find optimal control interventions to stop (or reverse) disease progression. Thus, it is …


Deception Pass State Park Internship, Sadie Sheller Jan 2022

Deception Pass State Park Internship, Sadie Sheller

College of the Environment Internship Reports

My learning objectives for the summer were to improve my skills speaking to lay audiences, as well as to solidify what I have learned in the past about the ocean and tidepool environments. I wanted to be able to deepen my understanding of the world around me while sharing my love for the natural world with park visitors in the hopes that they too would decide they love the natural world as well.


Skagit Fisheries Enhancement Group Restoration Internship, Meridith Mccannon Jan 2022

Skagit Fisheries Enhancement Group Restoration Internship, Meridith Mccannon

College of the Environment Internship Reports

The importance of both the restoration and preservation of riparian habitats was already something I was very interested in, but this internship helped me so much in understanding what it takes to actually restore these precious ecosystems. Skagit Fisheries Enhancement Group, or SFEG, is a nonprofit organization which aims to protect and improve the Skagit River watershed in order to aid in the revitalization of salmon and trout species which depend on it. There are so many different ways in which SFEG has contributed to the restoration of essential habitat along the Skagit River, all of which have shown to …


Machine-Learning And Meta-Analysis Techniques To Quantify And Predict Soil Organic Carbon, N2O-N And Co2-C Emissions In Cover Crop Systems, Deepak Raj Joshi Jan 2022

Machine-Learning And Meta-Analysis Techniques To Quantify And Predict Soil Organic Carbon, N2O-N And Co2-C Emissions In Cover Crop Systems, Deepak Raj Joshi

Electronic Theses and Dissertations

People worldwide are challenged by multiple threats including climate change, growing populations, and soil degradation. Addressing these challenges requires understanding of the local environment, farming systems and modern technologies. These technologies include new ways to process information that include artificial intelligence, machine learning and meta-analysis. Models produced using these technologies may be useful for predicting the consequences of implementing conservation practices that reduce GHG emissions as well as for determining the carbon footprint of cropping systems that include environmentally friendly conservation technologies such as growing cover crop. Therefore, our objectives of this study were to: 1) provide an overview of …


Study On Performance Of Pruned Cnn-Based Classification Models, Mengling Deng Jan 2022

Study On Performance Of Pruned Cnn-Based Classification Models, Mengling Deng

Electronic Theses and Dissertations

Convolutional Neural Network (CNN) is a neural network developed for processing image data. CNNs have been studied extensively and have been used in numerous computer vision tasks such as image classification and segmentation, object detection and recognition, etc. [1] Although, the CNNs-based approaches showed humanlevel performances in these tasks [2], they require heavy computation in both training and inference stages, and the models consist of millions of parameters. This hinders the development and deployment of CNN-based models for real world applications. Neural Network Pruning and Compression techniques have been proposed [3, 4] to reduce the computation complexity of trained CNNs …


Diversity And Inclusion In Science Teaching Learning (Distl): Focusing On The Perspectives Of Undergraduate Students And Graduate Teaching Assistants In The Chemistry Classroom, Albert Aidoo Jan 2022

Diversity And Inclusion In Science Teaching Learning (Distl): Focusing On The Perspectives Of Undergraduate Students And Graduate Teaching Assistants In The Chemistry Classroom, Albert Aidoo

Electronic Theses and Dissertations

Students in Science, Technology, Engineering and Mathematics (STEM) come with a wide range of experiences and educational backgrounds. There is high attrition rate and low academic achievement among students in STEM areas, specifically in college chemistry courses that are prerequisites for many STEM majors. Hence it is important to look at diversity and inclusion specifically in first- and second-year college chemistry courses to address the challenge of student attrition in STEM. Diversity can be understood as the differences each student brings along the dimensions of prior knowledge, skills, race, ethnicity, sexual orientation, gender, socio-economic status, age, ability, religious or political …


Disentangling The Complex Evolutionary History Of Invasive Russian Thistle: Phylogenetic Relationships, The Role Of Hybridization, And Public Engagement, Deva Raj Khanal Jan 2022

Disentangling The Complex Evolutionary History Of Invasive Russian Thistle: Phylogenetic Relationships, The Role Of Hybridization, And Public Engagement, Deva Raj Khanal

Electronic Theses and Dissertations

No abstract provided.


Pathogen Prevalence In Domestic Sheep In Western Nebraska: Implications For Bighorn Sheep Conservation And Coexistence On A Multi-Use Landscape, Kaytlin Bohr Jan 2022

Pathogen Prevalence In Domestic Sheep In Western Nebraska: Implications For Bighorn Sheep Conservation And Coexistence On A Multi-Use Landscape, Kaytlin Bohr

Electronic Theses and Dissertations

Bighorn sheep (Ovis canadensis) and domestic sheep (Ovis aries) are members of the same genus and thus share multiple pathogens that can be spread between them. One specific respiratory pathogen of concern is Mycoplasma ovipneumoniae (M. ovipneumoniae), which has been linked to pneumonia epizootics in bighorn sheep that are often characterized by all age die offs upon initial exposure followed by years of low lamb recruitment. Domestic sheep have been identified as one carrier of M. ovipneumoniae with transmission between sheep species occurring when there is close contact on the landscape. To prevent this cross-species transmission, importance has been placed …


Studying Spread Patterns Of Covid-19 Based On Spatiotemporal Data, Beiyu Lin, Xiaowei Jia, Zhiqian Chen Jan 2022

Studying Spread Patterns Of Covid-19 Based On Spatiotemporal Data, Beiyu Lin, Xiaowei Jia, Zhiqian Chen

Computer Science Faculty Publications and Presentations

The current COVID-19 epidemic have transformed every aspect of our lives, especially our behavior and routines. These changes have been drastically impacting the economy in each region, such as local restaurants and transportation systems. With massive amounts of ambient data being collected everywhere, we now can develop innovative algorithms to have a much greater understanding of epidemic spread patterns of COVID-19 based on spatiotemporal data. The findings will open up the possibility to design adaptive planning or scheduling systems that will help preventing the spread of COVID-19 and other infectious diseases.

In this tutorial, we will review the trending state-of-theart …


Unique Assembly Verification In Two-Handed Self-Assembly, David Caballero, Timothy Gomez, Robert Schweller, Tim Wylie Jan 2022

Unique Assembly Verification In Two-Handed Self-Assembly, David Caballero, Timothy Gomez, Robert Schweller, Tim Wylie

Computer Science Faculty Publications and Presentations

One of the most fundamental and well-studied problems in Tile Self-Assembly is the Unique Assembly Verification (UAV) problem. This algorithmic problem asks whether a given tile system uniquely assembles a specific assembly. The complexity of this problem in the 2-Handed Assembly Model (2HAM) at a constant temperature is a long-standing open problem since the model was introduced. Previously, only membership in the class coNP was known and that the problem is in P if the temperature is one (τ=1). The problem is known to be hard for many generalizations of the model, such as allowing one step into the third …


Ms Environmental Biology Capstone Project, Samantha Ortega Jan 2022

Ms Environmental Biology Capstone Project, Samantha Ortega

Regis University Student Publications (comprehensive collection)

This project is presented in partial fulfillment of the requirements for the degree Masters of Science in Environmental Biology at Regis University. Chapter 1 is a literature review that discusses the management implications of designing bird habitat on anthropogenic structures. Chapter 2 is a grant proposal to explore niche dominance by anthropophilic bird species in Denver, CO. Chapter 3 is a journal manuscript discussing how musth impacts captive bull Asian elephant (Elephas maximus) behavior at Denver Zoo. Finally, Chapter 4 is a stakeholder analysis for Northern Bobwhite recovery at Bridgestone-Firestone Centennial Wilderness Area, White County, Tennessee.


Ms Environmental Biology Capstone Project, Dylan Brown Jan 2022

Ms Environmental Biology Capstone Project, Dylan Brown

Regis University Student Publications (comprehensive collection)

Chapter 1- Revisiting Tamarisk Invasion in Riparian Ecosystems: An Argument Against Single Species Management of the Southwestern Willow Flycatcher (Empidonax traillii extimus)

Chapter 2- Temporal Trends of Tamarisk Remediation to Native Vegetation Establishment

Chapter 3- Assessing Effectiveness of Tamarisk Removal Treatments Through a Meta Regression Analysis

Chapter 4- Legal Challenges of Tamarisk Removal in the Southwestern United States


The Efficacy Of The South Dakota State University Summer Jacks Leap Program, Tessa M. Sundermann Jan 2022

The Efficacy Of The South Dakota State University Summer Jacks Leap Program, Tessa M. Sundermann

Electronic Theses and Dissertations

Today, several studies detail the continuing struggle many students have with college mathematics courses at universities across the United States. The South Dakota State University Summer Jacks LeaP program is a summer bridge mathematics program aimed at improving incoming students’ mathematics success. This analysis used a mixed methods research design to examine the efficacy of the Summer Jacks LeaP program. First, we analyzed the LeaP students’ homework averages, exam 1 scores, final exam scores, and overall grade scores to determine if they were finding success in their fall semester mathematics courses. We also used hypothesis testing to compare LeaP participants …


Statistical Theory For Specialized Linear Regression Adjustment Methods Compared To Multiple Linear Regression In The Presence And Absence Of Interaction Effects, Leon Su Jan 2022

Statistical Theory For Specialized Linear Regression Adjustment Methods Compared To Multiple Linear Regression In The Presence And Absence Of Interaction Effects, Leon Su

Theses and Dissertations--Statistics

When building models to investigate outcomes and variables of interest, researchers often want to adjust for other variables. There is a variety of ways that these adjustments are performed. In this work, we will consider four approaches to adjustment utilized by researchers in various fields. We will compare the efficacy of these methods to what we call the ”true model method”, fitting a multiple linear regression model in which adjustment variables are model covariates. Our goal is to show that these adjustment methods have inferior performance to the true model method by comparing model parameter estimates, power, type I error, …


Deriving The Distributions And Developing Methods Of Inference For R2-Type Measures, With Applications To Big Data Analysis, Gregory S. Hawk Jan 2022

Deriving The Distributions And Developing Methods Of Inference For R2-Type Measures, With Applications To Big Data Analysis, Gregory S. Hawk

Theses and Dissertations--Statistics

As computing capabilities and cloud-enhanced data sharing has accelerated exponentially in the 21st century, our access to Big Data has revolutionized the way we see data around the world, from healthcare to investments to manufacturing to retail and supply-chain. In many areas of research, however, the cost of obtaining each data point makes more than just a few observations impossible. While machine learning and artificial intelligence (AI) are improving our ability to make predictions from datasets, we need better statistical methods to improve our ability to understand and translate models into meaningful and actionable insights.

A central goal in the …


Beta Mixture And Contaminated Model With Constraints And Application With Micro-Array Data, Ya Qi Jan 2022

Beta Mixture And Contaminated Model With Constraints And Application With Micro-Array Data, Ya Qi

Theses and Dissertations--Statistics

This dissertation research is concentrated on the Contaminated Beta(CB) model and its application in micro-array data analysis. Modified Likelihood Ratio Test (MLRT) introduced by [Chen et al., 2001] is used for testing the omnibus null hypothesis of no contamination of Beta(1,1)([Dai and Charnigo, 2008]). We design constraints for two-component CB model, which put the mode toward the left end of the distribution to reflect the abundance of small p-values of micro-array data, to increase the test power. A three-component CB model might be useful when distinguishing high differentially expressed genes and moderate differentially expressed genes. If the null hypothesis above …


Classifying Blood Glucose Levels Through Noninvasive Features, Rishi Reddy Jan 2022

Classifying Blood Glucose Levels Through Noninvasive Features, Rishi Reddy

Graduate Theses, Dissertations, and Problem Reports

Blood glucose monitoring is a key process in the prevention and management of certain chronic diseases, such as diabetes. Currently, glucose monitoring for those interested in their blood glucose levels are confronted with options that are primarily invasive and relatively costly. A growing topic of note is the development of non-invasive monitoring methods for blood glucose. This development holds a significant promise for improvement to the quality of life of a significant portion of the population and is overall met with great enthusiasm from the scientific community as well as commercial interest. This work aims to develop a potential pipeline …


Periodic Points Of Polynomials Over Finite Fields, Derek Garton Jan 2022

Periodic Points Of Polynomials Over Finite Fields, Derek Garton

Mathematics and Statistics Faculty Publications and Presentations

Fix an odd prime p. If r is a positive integer and f is a polynomial with coefficients in Fpr, let Pp,r⁡(f) be the proportion of P1⁢(Fpr) that is periodic with respect to f. We show that as r increases, the expected value of Pp,r⁡(f), as f ranges over quadratic polynomials, is less than 22/(log⁡log⁡pr). This result follows from a uniformity theorem on specializations of dynamical systems of rational functions over residually finite Dedekind domains. The specialization theorem generalizes previous work by Juul et al. that holds for rings of integers of number fields. Moreover, under stronger hypotheses, we effectivize …


Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier Jan 2022

Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier

Electronic Theses and Dissertations

Grasslands historically covered 46 million km2 of Earth’s surface representing nearly 42% of the living vegetation. Encroachment of woody species onto grasslands and savannas is a widely researched global phenomenon, with eastern redcedar (ERC) (Juniperus virginiana L.) trees being the most prominent woody encroacher in the Northern Great Plains (NGP) due to the lack of prescribed fire and planted ERC escaping from shelterbelts. This encroachment poses a threat to native plant communities in terms of their reproduction, regeneration, and diversity. ERC are fierce competitors and can establish in most soil types, are drought tolerant, and prolific seed reproducers. These qualities …


Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor Jan 2022

Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor

Electronic Theses and Dissertations

The Prairie Pothole Region (PPR) of North America provides critical habitat for waterfowl across life stages, but anthropogenic changes to the landscape have negatively impacted habitat quality for waterfowl. The mallard (Anas platyrhynchos) is abundant and socioeconomically valuable in the PPR, as it is a preferred target species of waterfowl hunters. Extensive research has evaluated breeding ecology of mallards in the PPR, but the period between juvenile mallards fledging and migrating has rarely been studied. The post-fledging ecology of juvenile mallards is a vital consideration for comprehensive waterfowl management. Further, juvenile mallards are a significant portion of hunter harvest at …


Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield Jan 2022

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …