Digital Commons Network^™

Visualization Of Productivity Zones Based On Nitrogen Mass Balance Model In Narragansett Bay, Rhode Island, Jongsun Kim, Myung Hwangbo, Patricia S. Thibodeau, Georgia Rhodes, Emma Hogarth, Stewart Copeland

School of Earth, Environmental, & Marine Sciences Faculty Publications

Primary productivity in the coastal regions, linked to eutrophication and hypoxia, provides a critical understanding of ecosystem function. Although primary productivity largely depends on riverine nutrient inputs, estimation of the extent of riverine nutrient influences in the coastal regions is challenging. A nitrogen mass balance model is a practical tool to evaluate coastal ocean productivity to understand biological mechanisms beyond data observations. This study visualizes the biological production zones in Narragansett Bay, Rhode Island, USA, where hypoxia frequently occurs, by applying a nitrogen mass balance model. The Bay is divided into three zones - brown, green, and blue zones - …

Noise Analysis Of The Indian Pulsar Timing Array Data Release I, Aman Srivastava, Shantanu Desai, Neel Kolhe, Mayuresh Surnis, Bhal Chandra Joshi, Abhimanyu Susobhanan, Aurélien Chalumeau, Shinnosuke Hisano, Nobleson K, Raghav Girgaonkar

Physics & Astronomy Faculty Publications

The Indian Pulsar Timing Array (InPTA) collaboration has recently made its first official data release (DR1) for a sample of 14 pulsars using 3.5 years of uGMRT observations. We present the results of single-pulsar noise analysis for each of these 14 pulsars using the InPTA DR1. For this purpose, we consider white noise, achromatic red noise, dispersion measure (DM) variations, and scattering variations in our analysis. We apply Bayesian model selection to obtain the preferred noise models among these for each pulsar. For PSR J1600−3053, we find no evidence of DM and scattering variations, while for PSR J1909−3744, we find …

Asymptotics And Sign Patterns For Coefficients In Expansions Of Habiro Elements, Ankush Goswami, Abhash Kumar Jha, Byungchan Kim, Robert Osburn

School of Mathematical & Statistical Sciences Faculty Publications

We prove asymptotics and study sign patterns for coefficients in expansions of elements in the Habiro ring which satisfy a strange identity. As an application, we prove asymptotics and discuss positivity for the generalized Fishburn numbers which arise from the Kontsevich–Zagier series associated to the colored Jones polynomial for a family of torus knots. This extends Zagier’s result on asymptotics for the Fishburn numbers.

Catalan Numbers As Discrepancies For A Family Of Substitutions On Infinite Alphabets, Dirk Frettlöh, Alexey Garber, Neil Mañibo

School of Mathematical & Statistical Sciences Faculty Publications

In this work, we consider a class of substitutions on infinite alphabets and show that they exhibit a growth behaviour which is impossible for substitutions on finite alphabets. While for both settings the leading term of the tile counting function is exponential (and guided by the inflation factor), the behaviour of the second-order term is strikingly different. For the finite setting, it is known that the second term is also exponential or exponential times a polynomial. We exhibit a large family of examples where the second term is at least exponential in n divided by half-integer powers of n, where …

Effect Of Total Population, Population Density And Weighted Population Density On The Spread Of Covid-19 In Malaysia, Hui Shan Wong, Md Zobaer Hasan, Omar Sharif, Azizur Rahman

School of Mathematical & Statistical Sciences Faculty Publications

Since November 2019, most countries across the globe have suffered from the disastrous consequences of the Covid-19 pandemic which redefined every aspect of human life. Given the inevitable spread and transmission of the virus, it is critical to acknowledge the factors that catalyse transmission of the disease. This research investigates the relation of the external demographic parameters such as total population, population density and weighted population density on the spread of Covid-19 in Malaysia. Pearson correlation and simple linear regression were utilized to identify the relation between the population-related variables and the spread of Covid-19 in Malaysia using data from …

Endoscopic Sleeve Gastroplasty (Esg) Versus Laparoscopic Sleeve Gastroplasty (Lsg): A Comparative Review, Basil N. Nduma, Kelly A. Mofor, Jason Tatang, Loica Amougou, Stephen Nkeonye, Princess Chineme, Chukwuyem Ekhator, Solomon Ambe

Health & Biomedical Sciences Faculty Publications

Obesity is one of the most debilitating conditions. In a quest to mitigate disease severity, various interventions have been proposed, with endoscopic sleeve gastroplasty (ESG) and laparoscopic sleeve gastroplasty (LSG) being among the recent interventions that have received growing attention. This systematic review sought to conduct a comparative analysis regarding the efficacy, effectiveness, and safety of both interventions.

The study involved a systematic review in which key search engines were used to select articles documented and published in the last decade. The articles for inclusion were those existing as peer-reviewed studies touching upon the aforementioned subject, with both controlled and …

Advanced Prognostic Modeling For Breast Cancer Patients: Leveraging Data-Driven Approaches For Survival Analysis, Theophilus Gyedu Baidoo

Theses and Dissertations

Breast cancer is the second most prevalent form of cancer in women in the United States. Each year, about 264,000 cases of breast cancer are diagnosed in women and of this number, about 42,000 women lose their lives as reported by the Centers for Disease Control and Prevention. Early detection and effective treatment are crucial for improving survival rates and reducing mortality. This study aimed to explore the influential factors that may risk the survival of women with the disease and compare their predictive abilities using several error and performance metrics. The study uses a dataset from the National Cancer …

Applications Of Environmental Dna (Edna) To Detect Subterranean And Aquatic Invasive Species: A Critical Review On The Challenges And Limitations Of Edna Metabarcoding, Sakib Tahmid Rishan, Richard Kline, Md Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

The world is struggling to solve a devastating biodiversity loss that not only affects the extinction of treasured species and irreplaceable genetic variation, but also jeopardizes the food production, health, and safety of people. All initiatives aimed to conserve biodiversity rely heavily on the monitoring of both species and populations to get accurate spatial patterns and overall population assessments. Conventional monitoring techniques, such as visual surveys and counting individuals, are problematic due to challenges in identifying cryptic species or immature life stages. Environmental DNA (eDNA) is a relatively new technology that has the potential to be a faster, non-invasive, and …

Optimizing Convolutional Neural Networks For Transient Detection In Optical Astronomy With Augmented Datasets, Wendy Mendoza

Theses and Dissertations

We present a technique for optical transient detection using artificial neural networks, particularly a Convolutional Neural Network (CNN), a deep learning algorithm. This method analyzes images of the same area of the sky captured by several telescopes, with one image serving as a reference for a probable transient’s epoch and the other as an image from a previous epoch. We train the CNN on simulated sources and test it on actual image data samples using data from the Dr. Cristina V. Torres Memorial Astronomical Observatory and Sloan Digital Sky Survey. This autonomous detection method replaces the standard procedure, which involves …

Using Deep Learning For Encrypted Traffic Analysis Of Amazon Echo, Surendra Pathak

Theses and Dissertations

The adoption of the Amazon Echo family of devices in modern homes has become very widespread at the current time, with hundreds of millions of devices sold. Moreover, the global smart speaker market size is growing vigorously and is projected to continue to bigger. Smart speakers allow users hands-free interaction by allowing voice control, promoting human-computer interaction to greater avenues. Though smart speaker can be useful assistant, it has some serious security concerns that need to be studied. In this study, an analysis of the security and privacy concerns of smart speakers is presented along with a passive attack, namely …

Identification Of Heart Disorders With Symbolic Aggregate Approximation, Moses K. Owusu

Theses and Dissertations

This project is an application of the Symbolic Aggregate Approximation (SAX) to 1000 fragments of ECG signals for 45 patients (42% females aged between 23 and 89 years and 58% males aged 32 to 89 years) using data obtained from the MIH-BIH Arrhythmia database to recognize cardiac health disorders. Data include a normal sinus rhythm, pacemaker rhythm and ECG readings for 15 heart disorders, making 17 in total. The aim is to use SAX to classify heart disorders using ECG signal, that analyzes QRS-complexes by first splitting the time series into smaller equally sized segments using the Piecewise Aggregate Approximation …

Defect-Based Approaches To Achieving Robust Modes In Hermitian And Non-Hermitian Systems, Fargol Seifollahi

Theses and Dissertations

A hallmark of topological physics has been its ability to facilitate wave propagation control and confinement. This thesis will be focused on wave localization and the existence of robust modes for one of the earliest and most important models of topological insulators, known as the Su-Schrieffer-Heeger (SSH) model. The first chapter covers some of the fundamental topics including the general SSH Hamiltonian, as well as the concept of bulk-boundary correspondence, winding number and distinction between the topologically trivial and non-trivial phases. We investigate the existence of two almost-zero energy states for a finite-sized topologically non-trivial SSH array which are exponentially …

A Data-Driven Method For Damage Detection In An Open Deck Steel Truss Railroad Bridge Under The Moving Train Load, Mahesh Pokhrel

Theses and Dissertations

Open-Deck (OD) steel truss railroad bridges are one of the most common types of railroad bridges in the United States. They are, however, significantly vulnerable to the dynamic effects of moving train load. In the long run, these dynamic effects cause fatigue damage to the structural members. The damage in most of the railroad bridges are monitored by visual inspections which are sometimes unreliable and inconsistent due to human error. This study explores the identification and classification of damage to an open deck railroad bridge from both time-domain (statistical features) and time-frequency domain features (Hilbert-Huang Transform) extracted through acceleration response …

Analyzing The On Source Window Of Supernova Sn2019ejj With A Multi Layered Signal Enhancement Algorithm With Coherent Waveburst And A Convolutional Neural Network, Michael Gale Benjamin

Theses and Dissertations

Core collapse supernovae (CCSN) are highly anticipated sources of gravitational waves during the fourth observation run (O4). CCSN signals are weak and unmodeled and the rate of occurrence in our galaxy is very low. Because of this, they provide a greater challenge to detect than previously detected GW sources. CCSN simulations are used to test the detection pipeline in the event a CCSN is detected. CCSN GW signals are often indistinguishable from the noise sources present in GW data. We present a multi layered signal enhancement pipeline which we have applied Machine Learning (ML) techniques. We have used a Convolutional …

Spatiotemporal Modulated Non-Hermitian Structures And Their Application In Photonic Devices, Amir Targholizadeh

Theses and Dissertations

Periodically refractive index modulation has been known as a novel method to introduce non-reciprocity in optical lattices inspiring many works to propose on-chip optical components such as optical insulators and amplifiers. This type of modulation by coupling two waveguide propagating modes, let them exchange a population called photonic intraband transition. This modulation type also can be applied to the imaginary part of the refractive index, which perturbs the absorption in the waveguide. Non-hermitian physics is a promising field that studies physical effects in such systems without energy conservation. These systems have degeneracy points called Exceptional points in which two or …

Exploring The Localization Of Light In Discrete Systems With Conducted Symmetries, Aria Hajikhani

Theses and Dissertations

Controlling the localization of light has been studied through many approaches and has become a subject matter of interest due to potential applications in various fields. In this thesis, we will explore discrete systems with conducted symmetries, in both quantum and classical aspects, to establish a deeper understanding of light localization. First, we investigate atom-light interactions through exploring the Jaynes-Cummings model. We then introduce coupled cavity arrays (CCAs) where photons can hop between neighboring cavities and each cavity in the array may interact with one or more atoms. Specifically, we focus on systems in which one two-level atom is connected …

Image Segmentation With Human-In-The-Loop In Automated De-Caking Process For Powder Bed Additive Manufacturing, Vincent Opare Addo Asare-Manu

Theses and Dissertations

Additive manufacturing (AM) becomes a critical technology that increases the speed and flexibility of production and reduces the lead time for high-mix, low-volume manufacturing. One of the major bottlenecks in further increasing its productivity lies around its post-processing procedures. This work focuses on tackling a critical and inevitable step in powder-bed additive manufacturing processes, i.e., powder cleaning or de-caking. Pressing concerns can be raised with human involvement when performing this task manually. Therefore, a robot-driven automatic powder cleaning system could be an alternative to reducing time consumption and increasing safety for AM operators. However, since the color and surface texture …

Navigating Context And Perception: A Qualitative Study On Instructional Coaching, Christie Lizette Esparza

Theses and Dissertations

This qualitative case study explored the perceptions of instructional coaches in order to understand the ways in which context influenced their view of their roles and how they supported teacher growth. The theoretical and conceptual foundations for this study include a distributed perspective, a phenomenologically informed lens, and a pragmatic worldview. The sample consisted of 9 elementary instructional coach participants from different content areas and programs provided within the site. Semi-structured interviews, a focus group, and a review of the district’s instructional coaching program documents were used, and thematic analysis led to four findings that encompassed the contextual conditions that …

A Convolutional Neural Network Based Approach To Study The Gravitational Waves From Core-Collapse Supernovae In Ligo's Third Observation Run: Detection Efficiency And Parameter Estimation, Bhawana Sedhai

Theses and Dissertations

Core-Collapse Supernova (CCSN) is one of the most anticipated sources of Gravitational Waves (GW) arriving at the advanced LIGO detectors during the fourth observation run (O4). CCSN are rare, weak and unmodeled having a very low rate of occurrence in our galaxy (estimated 2 per century). Thus, detection of GW from CCSN is a challenging problem. An analysis pipeline used in this study is Multi-Layer Signal Enhancement with cWB and CNN or MuLaSEcC that combines Machine Learning methods with a network of Gravitational Wave detectors to identify and reconstruct signals from core collapse supernovae, while minimizing false alarms through the …

Implementation Of Dual Language Programs For Emergent Bilinguals: Understanding Instructional Decisions Of Elementary Principals, Susana Marlet Arredondo

Theses and Dissertations

According to the United States Department of Education (2017), the number of K-12 Emergent Bilingual students (EBs) has been increasing over the years; in the year 2014 – 2015, there were over 4.8 million English Learners in our country. Therefore, a new norm for many school districts has been to incorporate Dual Language Programs to close the learning gaps between this subgroup and non-English Learners. There are different models used under Dual Language Program models such as the 90:10 and 50:50 model approach. Moreover, other districts provide a Dual Language Program for all students, not just English Learners. The purpose …

Development Of Intensity Duration Frequency Curve Of The Lower Rio Grande Valley, Binaya Poudel

Theses and Dissertations

Section 1: This chapter incorporates extensive information about the concept of Intensity-Duration-Frequency (IDF) curves, their historical development and usage, specific focus on the Lower Rio Grande Valley, and the importance of using a comprehensive 32-year data set from 1990-2022 to develop these curves.

Section 2: This chapter provides detailed information about the rigorous comparison of the developed IDF curves with previous ones, where past IDF curves were developed using an empirical formula method. The research presented here employs the Gumbel distribution method, providing a fresh perspective and potentially more accurate predictions of future weather extremes.

Section 3: This chapter outlines …

Decreased Moderate To Vigorous Physical Activity Levels In Children With Asthma Are Associated With Increased Traffic-Related Air Pollutants, Juan Aguilera, Soyoung Jeon, Amit U. Raysoni, Wen-Whai Li, Leah D. Whigham

School of Earth, Environmental, & Marine Sciences Faculty Publications

People with asthma, particularly young children, are more adversely aected by trac emissions-and regular exercise reduces asthma symptoms and improves lung function. We studied the relationship between air pollution and objectively measured physical activity in children with asthma who were attending a school near a freeway. We continuously monitored air pollutants-PM2.5, PM10, nitrogen dioxide (NO2), and ozone (O3)-at the school for 10 weeks and measured physical activity levels via accelerometry in children (n = 12, ages 6-12 years). Concentrations of PM2.5, PM10, and NO2 were negatively associated with moderate to vigorous physical activity (PM2.5 and PM10: p < .001; NO2: p = …

Covering By Planks And Avoiding Zeros Of Polynomials, Alexey Glazyrin, Roman Karasev, Alexandr Polyanskii

School of Mathematical & Statistical Sciences Faculty Publications

We note that the recent polynomial proofs of the spherical and complex plank covering problems by Zhao and Ortega-Moreno give some general information on zeros of real and complex polynomials restricted to the unit sphere. As a corollary of these results, we establish several generalizations of the celebrated Bang plank covering theorem. We prove a tight polynomial analog of the Bang theorem for the Euclidean ball and an even stronger polynomial version for the complex projective space. Specifically, for the ball, we show that for every real nonzero d-variate polynomial P of degree n⁠, there exists a point in the …

Integrable Discretizations For A Generalized Sine-Gordon Equation And The Reductions To The Sine-Gordon Equation And The Short Pulse Equation, Han-Han Sheng, Bao-Feng Feng, Guo-Fu Yu

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, we propose fully discrete analogues of a generalized sine-Gordon (gsG) equation utx=(1+ν∂2x)sinu. The bilinear equations of the discrete KP hierarchy and the proper definition of discrete hodograph transformations are the keys to the construction. Then we derive semi-discrete analogues of the gsG equation from the fully discrete gsG equation by taking the temporal parameter b→0. Especially, one full-discrete gsG equation is reduced to a semi-discrete gsG equation in the case of ν=−1 (Feng {\it et al. Numer. Algorithms} 2023). Furthermore, N-soliton solutions to the semi- and fully discrete analogues of the gsG equation in the determinant form …

Oxygen And Hydrogen Isotopic Evidence That KamaʻEhuakanaloa (LōʻIhi) Seamount Hydrothermal Systems Are Recharged By Deep Pacific Seawater, Eric W. Chan, Brianna A. Alanis, Christopher R. German, Darlene S. S. Lim, John A. Breier

School of Earth, Environmental, & Marine Sciences Faculty Publications

We observed negative and positive δ18O and δ2H deviations from fluids collected at Kamaʻehuakanaloa (previously known as Lōʻihi) seamount relative to Pacific seawater from the same depth. Hydrothermal vents on the crater floor of Pele's Pit at Kamaʻehuakanaloa, at a depth of 1320 m, had δ18O and δ2H values as low as −0.19‰ and −0.3‰, respectively. Seawater collected within the caldera, within a zone 45 m above the crater floor, had δ18O and δ2H values as high as 1.15‰ and 6.5‰, respectively. In comparison, Pacific seawater at 1200 m and 1400 m at nearby station ALOHA exhibit intermediate δ18O and …

Life Cycle Assessment Of Calcium Oxide Pretreatment Of Corn Stover With Carbon Dioxide Neutralization For Ethanol Production, Jikai Zhao, Danyi Feng, Juhee Lee

School of Earth, Environmental, & Marine Sciences Faculty Publications

This work used life-cycle assessment (LCA) to determine the environmental and human health impacts of four ethanol production scenarios (S1: CaO pretreatment + H2SO4 neutralization + C6 yeast fermentation; S2: CaO pretreatment + CO2 neutralization + C6 yeast fermentation; S3: CaO pretreatment + H2SO4 neutralization + C6/C5 yeast fermentation; and S4: CaO pretreatment + CO2 neutralization + C6/C5 yeast fermentation), with the functional unit being 1 kg of 95 % ethanol. The LCA results showed that the total ozone depletion, global warming potential, smog, acidification, eutrophication, and ecotoxicity values were comparable when CO2 or H2SO4 were used to adjust the …

Contractive Symmetric Matrix Completion Problems Related To Graphs, Sangmin Chun, In Hyoun Kim, Jaewoong Kim, Jasang Yoon

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, we consider the contractive real symmetric matrix completion problems motivated in part by studies on sparse (or dense) matrices for weighted sparse recovery problems and rating matrices with rating density in recommender systems. We completely characterize symmetric patterns P with the property (C) that every partially contractive real symmetric matrix with pattern P has a contractive real symmetric completion using graphs.

Bend And Not Break: Examining Hispanic Engineering Student's Academic Challenges During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Student success in higher education remains an area of interest, particularly for underrepresented minorities. Studies reveal that while Latino college enrollment has increased, retention rates continue to be an ongoing struggle. Several factors that attribute to such low rates include academic self-concept, family support, cognitive mapping, managing resources, background characteristics, and separation and maintenance of family ties. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, students were unable to utilize campus resources and engage in established educational campus practices. In this research …

Learning In Transition: Developing And Employing Pedagogical Supports To Enhance Student Learning In Engineering Education, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Scholarly research indicates that classroom environment and conditions influence the degree of student learning, levels of engagement, and overall success in engineering education. In the wake of COVID-19, educational institutions transitioned to fully online delivery that disrupted traditional and effective channels of communication enacted in classroom contexts. For a substantial number of faculty members, this rapid transition to a fully remote instructional context marked the start a novel style of teaching and learning environment, a grand departure from the traditional, direct face-to-face setting. Such rapid and disruptive change required creative solutions to routinized instructional practices and compelling faculty to adjust …

Leveling The Playing Field: Enacting Equitable Pedagogy To Teach Rigid Body Dynamics, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Research examining the quality of engineering programs across different instructions of learning has revealed that no two programs are alike. Each program has unique and distinctive features that influence the quality and rigor of education that students receive. Institutional culture, leadership, faculty preparedness, funding and many other factors influence program quality. Additionally, researchers have also noted that many institutional gaps and equity related issues are persistent and troublesome facets that further exacerbate the academic gaps in STEM education. It is within this context, that students attending top tier universities will likely have remarkedly vast academic experiences in terms of level …