Digital Commons Network^™

Mechanical Energy Harvester For Powering Rfid Systems Components: Modeling, Analysis, Optimization And Design, Alireza Babaei

Theses and Dissertations--Mechanical and Aerospace Engineering

Finding alternative power sources has been an important topic of study worldwide. It is vital to find substitutes for finite fossil fuels. Such substitutes may be termed renewable energy sources and infinite supplies. Such limitless sources are derived from ambient energy like wind energy, solar energy, sea waves energy; on the other hand, smart cities megaprojects have been receiving enormous amounts of funding to transition our lives into smart lives. Smart cities heavily rely on smart devices and electronics, which utilize small amounts of energy to run. Using batteries as the power source for such smart devices imposes environmental and …

Multiscale Modeling Of Cardiac Growth And Baroreflex Control, Hossein Sharifi

Theses and Dissertations--Mechanical and Aerospace Engineering

The heart functions within a complex system that adapts its function to any alteration in loading via several mechanisms. For example, the baroreflex is a short-term feedback loop that modulates the heart's function on a beat-to-beat basis to control arterial pressure. On the other hand, cardiac growth is a long-term adaptive response that occurs over weeks or months in response to changes in left ventricular loading. Understanding the mechanisms that drive ventricular growth and biological remodeling is critical to improving patient care. Multiscale models of the cardiovascular system have emerged as effective tools for investigating G&R, offering the ability to …

Machine Learning For Advancing Automation And Quality Control In Robotic Welding, Joseph Kershaw

Theses and Dissertations--Mechanical and Aerospace Engineering

Welding is a vital manufacturing process across a diverse range of industries to permanently join metallic components into needed assemblies. Though widely used and studied, the process is not fully understood due to the myriad of interconnected physics that present themselves during the welding process. Electrical, thermal, structural, and fluidic mechanics are simultaneously at work influencing one another to achieve the bonding that manufacturers desire. In addition to general manufacturing issues, such as tool wear or misalignment, micro-level changes to the material structure and composition can have cascading impacts on the final weld. This complexity makes it difficult, if not …

A Computational Fluid Dynamic Analysis Of Oxyacetylene Combustion Flow For Use In Material Response Boundary Conditions, Craig Meade

Theses and Dissertations--Mechanical and Aerospace Engineering

Oxyacetylene torches are used in the aerospace industry and research to test thermal protection system materials (TPS) due to their high flame temperatures and high heat flux capabilities. The purpose of this work is to determine a combustion model to accurately simulate the high temperature flow of an oxyacetylene torch. The flow conditions around a sample material can then be used as boundary conditions when modeling TPS material response. Two separate combustion models with equilibrium chemistry were investigated using ANSYS Fluent™; the Eddy-Dissipation Model, and the Partially Premixed model.The results of this study are compared to existing experiments for validation.

Generalizable And Adaptable Data-Driven Methods For Overcoming Barriers To Practical Industrial Condition Monitoring, Matthew B. Russell

Theses and Dissertations--Electrical and Computer Engineering

The future of smart manufacturing relies on predictive maintenance systems that intelligently minimize expensive downtime through timely assessment of machine condition. Deep Learning (DL) has achieved excellent performance in industrial condition monitoring experiments, but the constraints of the manufacturing environment prevent many algorithms from being practically deployed on the factory floor. Ubiquitous sensing from online machines generates high velocity data streams that require new techniques for efficient transmission and storage. Despite these ever-increasing data lakes, many applications still lack the data needed for training DL fault diagnosis and wear tracking models since most data is unlabeled and only from nominal …

Stratospheric Glider Measurements Of Atmospheric Parameters, Anisa Haghighi

Theses and Dissertations--Mechanical and Aerospace Engineering

In June 2021 a series of high altitude flights were conducted in Spaceport America, NM, using a balloon launched Uncrewed Aircraft System (UAS) to assess its capability to conduct measurements of various atmospheric properties and study turbulence in the troposphere and lower stratosphere. This UAS descends using an automated flight trajectory. The instruments aboard included a NASA-developed infrasonic microphone to evaluate its remote turbulence detection capabilities and a five-hole probe capable of measuring the in situ wind vector. Also on board were temperature, humidity and wind profile sensors. This document focuses on the atmospheric properties measured at high altitudes, the …

Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …

Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha

Theses and Dissertations--Mechanical and Aerospace Engineering

The objective of this research is to improve precision meteorological prediction, benefiting both uncrewed aerial vehicle (UAV) operations by avoiding hazardous flight conditions and tracking contaminant or toxic clouds caused by incidents, accidents, or fires. The operational concept is to collect meteorological observations from instruments mounted on a swarm of UAVs, telemeter the data to a weather simulation model, revise the predicted solution by adapting the flow field to the observations, and then transmit the updated forecast to appropriate personnel as well as to the guidance system of UAVs for repositioning to the next set of most beneficial measurements. While …

Economics Of Maple Syrup Production In Kentucky, Bobby Thapa

Theses and Dissertations--Forestry and Natural Resources

Maple syrup production is traditionally associated with New England regions in the United States, but there is growing interest in expanding it to other regions with suitable environmental conditions, including Kentucky. This study presents an in-depth analysis of the potential production and economic impacts of maple syrup in Kentucky using a multi-method approach. First, the study applies a stochastic production model to assess the effects of climatic and tree variables on maple syrup yield. The results reveal that several variables, including the number of maple trees, taps, temperatures, tapping season length, and time, significantly affect maple syrup yield. Second, input-output …

The Effect Of Land-Cover/Land-Use And Habitat Fragmentation On Spatial Patterns Of Lyme Disease In The Eastern United States, Maria Elizabeth Topmiller

Theses and Dissertations--Forestry and Natural Resources

Lyme disease has been of national concern for the past few decades. As our understanding of the role of landscape structure in epidemiology expands, it is essential to apply the principles of landscape ecology to the research of vector-borne and zoonotic disease. This study examined the strength of the relationship between land-cover class, degree of habitat fragmentation and county-level Lyme disease cases. Forest, agricultural, and urban land cover types were the categories of interest, while percent cover, edge density, and patch density were the landscape metric used to measure habitat amount and fragmentation. The general linear trends were modelled with …

Microalgae Immobilization With Filamentous Fungi: Process Development For Sustainable Food Systems, Suvro Talukdar

Theses and Dissertations--Biosystems and Agricultural Engineering

Demand for sustainable food sources has increased because of the rapid growth of the world's population.  In this study, microalgae cells of Haematococcus pluvialis were immobilized using the edible fungal strain Aspergillus awamori for potential food applications. The study investigated the impact of fungal loading, pellet geometry, and initial microalgae cell concentration on the immobilization performance and product characteristics. It was found that higher fungal loading and larger fungal pellets contributed to increased immobilization performance while increased initial microalgae concentration inhibited the process. Larger fungal pellets had decreased biomass density, which led to decreased surface concentration of immobilized microalgae but …

Unmanned Aircraft Systems For Precision Meteorology: An Analysis Of Gnss Position Measurement Error And Embedded Sensor Development, Karla S. Ladino

Theses and Dissertations--Biosystems and Agricultural Engineering

The overarching objective of this research was to enhance our comprehension of the three-dimensional precision of meteorological measurements obtained using small unmanned aircraft systems (UAS). Two complimentary experiments were conducted to achieve this objective.

The first experiment entailed the development and implementation of a system to determine the global navigation satellite system (GNSS) position accuracy on a UAS platform. This system was utilized to assess the static and dynamic accuracy of L1 and L1/L2 GNSS receivers in real-time kinematic (RTK) and non-RTK fix modes. Adjusted two-sample t-tests revealed significant differences in horizontal and vertical error between RTK and non-RTK receivers …

Language Accessibility And Voting: How Effective Has The Law Been?, Celina Beatriz Curillo

Student Works

No abstract provided.

A Cybersecurity “Standard Of Care” For Critical Infrastructure, John Klaczany

Student Works

No abstract provided.

Ensuring Proper Enforcement Of Cryptocurrency Arbitration Clauses: A Call For Supreme Court Intervention, Daniel Keinan

Student Works

No abstract provided.

Pacifism And The Science Of War: Jane Addams And Bertrand Russell On World War I, Marilyn Fischer

Philosophy Faculty Publications

In July 1915, after hearing Jane Addams speak in London on her efforts for peace during wartime, Bertrand Russell wrote to an American friend, “You can gather what I think and feel by talking to Miss Addams. She seemed to me to have exactly the same outlook as I have.” In this paper I compare how Russell and Addams used the era’s scientific theories in formulating their pacifism. After recounting Addams’s and Russell’s experiences during the war, I show how Addams and Russell accounted for civilization’s “descent into barbarism” in parallel ways. I then contrast their conceptions of what counts …

Precipitation Recorded In The Turkana Basin From 2005 To 2022., Acacia Leakey, Greg Henkes, Mae Saslaw, Dino Martins

Geosciences Research Data

This is a dataset of precipitation recorded at three sites in northern Kenya near Lake Turkana using standard rain gauges. The data was recorded at the Koobi Fora Research Station (3.947736, 36.186166) from March 2003 until 2006, at the Turkana Basin Institute’s Ileret facility (4.28510, 36.262158) from 2006 to 2022 and at the Turkana Basin Institute’s Turkwel facility (3.140825, 35.864599) from 2012 to 2022. The data was collected manually by TBI staff observing gradation lines on the collectors following rainfall events and recorded as a single total for each 24 hour period.

Approach To Problem Solving And Use Of Intuition By Engineering Technology Students, Meher Taleyarkhan, Anne M. Lucietto, Natalie L. F. Hobson, Therese M. Azevedo

School of Engineering Technology Faculty Publications

Engineering technology students often forgo a methodical approach of solving or answering questions on assignments or exams in favor of an intuition-based approach, emphasizing educated guessing (Broberg et al., 2008). Faculty observations have noted these student solutions often provide explanations, usually sans calculations, to support answers the students believe to be reasonable when in reality deviated from the correct answer. An extensive study was developed to assess several distinctions between student intuition and use of cognition in problem solving, as related to a generalized student population. The study was comprised of a survey and interview. The survey utilized two instruments, …

Biomarker Identification For Breast Cancer Types Using Feature Selection And Explainable Ai Methods, David E. La Rosa Giraud

Honors Undergraduate Theses

This paper investigates the impact the LASSO, mRMR, SHAP, and Reinforcement Feature Selection techniques on random forest models for the breast cancer subtypes markers ER, HER2, PR, and TN as well as identifying a small subset of biomarkers that could potentially cause the disease and explain them using explainable AI techniques. This is important because in areas such as healthcare understanding why the model makes a specific decision is important it is a diagnostic of an individual which requires reliable AI. Another contribution is using feature selection methods to identify a small subset of biomarkers capable of predicting if a …

Enabling Large-Scale Transportation Electrification For Shared And Connected Mobility Systems, Md Rakibul Alam

Graduate Thesis and Dissertation 2023-2024

Owing to advancements in technology, substantial investments within the automotive industry, and the formulation of supportive state policies, the future landscape of the transportation sector is poised to witness a shift from traditional internal combustion engine vehicles (ICEVs) to electric vehicles (EVs). While EVs have made inroads in the market, they still face significant hurdles in the form of range anxiety and prolonged charging durations, inhibiting their widespread adoption. To tackle these challenges, a comprehensive approach to smart transportation electrification is proposed, emphasizing the pivotal roles of infrastructure development, particularly in the allocation of charging stations, and strategic operational decisions, …

Optimizing Biomechanical Models: Estimation Of Muscle Tendon Parameters And Ankle Foot Orthosis Stiffness, Sepehr Ramezani

Electronic Theses and Dissertations, 2020-2023

The complexity of the human musculoskeletal system presents challenges in accurately identifying its characteristics, particularly due to the presence of redundant actuators on a single joint. Non-invasive measures are necessary to overcome these challenges. Optimization algorithms have emerged as a crucial tool to advance subject-specific musculoskeletal modeling allows a more realistic representation of biomechanical behaviors, enhancing our understanding of human movement and enabling better clinical decision-making. Furthermore, optimization algorithms play a vital role in customizing rehabilitation and assistive devices, such as orthoses and prostheses. The current ankle-foot orthosis (AFO) stiffness measurement methods require bulky, complex designs, and often permanent modification …

Material Appearance Modeling For Physically Based Rendering, Alexis Benamira

Graduate Thesis and Dissertation 2023-2024

Photorealistic rendering focuses on creating images with a computer that imitates pictures of reallife scenes as faithfully as possible. To achieve this, rendering algorithms require incorporating accurate modeling of how light interacts with various types of matter. For most objects, this model needs to account for the scattering of the light rays. However, this model falls short when rendering objects of sizes smaller or comparable to the wavelength of the incident light. In this case, new phenomena such as diffraction or interference are observed and have been characterized in optics. Digital rendering of those phenomena involve different light representations than …

Modeling Behavior And Vaccine Hesitancy For Predicting Daily Vaccination Inoculations Using Trends, Case, Death, And Twitter Sentiment Data, Talal Daghriri

Electronic Theses and Dissertations, 2020-2023

Over the past 100 years, epidemiological models have evolved to incorporate greater facets of the process. With the advent of social networking, massive computational power, population sentiment analysis can now be added to the epidemiological modeling process. Sentiment analysis is greater understanding of the fears, uncertainties, motivation, and trends of the public with respect to vaccination and associated events. Lack of public confidence in the efficacy of models, safety of vaccines, and appropriateness of policies confounds vaccine inoculation prediction. Sentiment analysis of social media is a seminal technique that accesses shared users' contents and tweets on the Twitter platform for …

Machine Learning Algorithms For Molecular Signature Identification With High-Throughput Genome Sequencing Data, Jiao Sun

Electronic Theses and Dissertations, 2020-2023

Powered by the high-throughput genomic technologies, the RNA sequencing (RNA-Seq) method is capable of measuring transcriptome-wide mRNA expressions and molecular activities in cells. Elucidation of gene expressions at the isoform resolution enables the detection of better molecular signatures for phenotype prediction, and the identified biomarkers may provide insights into the functional consequences of disease. This dissertation research focuses on developing advanced machine learning algorithms for mining large-scale RNA-Seq data in cancer transcriptome analysis. A platform-integrated model for transcript quantification (IntMTQ) is developed to improve the performance of RNA-Seq on isoform expression estimation. IntMTQ provides more precise RNA-Seq-based isoform quantification, and …

Dordt University 2023-24 Catalog, Dordt University. Registrar's Office

Academic Catalogs

Academic Catalog for 2023-24

Iere Annual Report 2023, Erin Largo-Wight, James Taylor, Kelly Rhoden, Ruby Cox, Nicole Lowe

Annual Reports

2023 Annual Report of the Institute for Environmental Research and Education

On Enhancing Security For Division Homomorphism With Elgamal, Marius Silaghi, Ameerah Alsulami

Electrical Engineering and Computer Science Faculty Publications

Secure auctions and machine learning in cloud in-creasingly employs multi-party and homomorphic en-cryption support. A modification to Elgamal public key cryptosystem was shown to enable homomorphic division using an encoding of plaintext as fractions with numerator and denominator encrypted separately. However we notice that unlike for other homomorphic cryptography schemes, the obtained division homomorphism allows for the retrieval of the input secrets from the result of the division. Since this cancels the benefit of the encryption, we propose the introduction of a masking operation based on random factors and discuss its success with operations in Zp and Q. © 2023 …

A Historical Analysis Of Accounting Salaries As A Key Factor In The Staffing Crisis, Susan Coomer Galbreath, Han-Sheng Chen, Mark Jobe

Journal of Business, Industry, and Economics

The accounting profession is facing a staffing crisis. Addressing the causes for the decline in the number of accounting professionals and collegiate accounting majors is a multifaceted problem. To remain competitive and overcome the staffing shortage, the accounting profession must analyze the causes and make appropriate adjustments. To this point, in February 2023, the American Institute of Certified Public Accountants (AICPA) issued a draft plan that tackles eight root causes that are negatively impacting the accounting talent pipeline. Interestingly, salary challenges are not included in the eight root causes examined by the AICPA’s plan. This article analyzes the history of …

Do You Have To Attend To Succeed: Is There A Relationship Between Class Attendance And Final Grades, Michael Monahan, Amit Shah

Journal of Business, Industry, and Economics

University classes have a variety of assessments to determine if the students have learned the material. However, the researchers contend attendance is a strong predictor of class success. By comparing the number of absences and the final grade, statistically significant relationships were found. The variables of gender and academic major were also examined to ascertain if they are factors. Interesting conclusions were made as well as implications for practice.

Investigating Relationships Found In The Kidney Microenvironment To Aid In Understanding Malfunctions Of Proteins In Chronic Kidney Disease, Ademide Ogunsina

Holster Scholar Projects

The kidneys are the filtration organ that helps filter out waste from our body. Kidney disease is an ailment that causes damage to the kidney so that it cannot filter our blood and other bodily fluids properly. It is also one of the least researched illnesses in the medical field. And with about 10-15 percent of the American population suffering from kidney disease, there is an urgency in finding more ways to help find a solution.

I examined the damaged kidney environment at the cellular level to find out what protein processes cause the malfunction of the kidneys. Methodologies employed …