Engineering Commons^™

Sparsity For Gradient-Based Optimization Of Wind Farm Layouts, Benjamin T. Varela, Andrew Ning

Faculty Publications

Optimizing wind farm layouts is an important step in designing an efficient wind farm. Optimizing wind farm layouts is also a difficult task due to computation times increasing with the number of turbines present in the farm. The most computationally expensive part of gradient- based optimization is calculating the gradient. In order to reduce the expense of gradient calculation, we performed a study on the use of sparsity in wind farm layout optimization. This paper presents the findings of the sparsity study and provides a method to use sparsity in wind farm layout optimization. We tested this sparsity method by …

Machine Learning Prediction Of Dod Personal Property Shipment Costs, Tiffany Tucker, Torrey J. Wagner, Paul Auclair, Brent T. Langhals

Faculty Publications

U.S. Department of Defense (DoD) personal property moves account for 15% of all domestic and international moves - accurate prediction of their cost could draw attention to outlier shipments and improve budget planning. In this work 136,140 shipments between 13 personal property shipment hubs from April 2022 through March 2023 with a total cost of $1.6B were analyzed. Shipment cost was predicted using recursive feature elimination on linear regression and XGBoost algorithms, as well as through neural network hyperparameter sweeps. Modeling was repeated after removing 28 features related to shipment hub location and branch of service to examine their influence …

Design Of An Internal Osculating Waverider Intake, Mark E. Noftz, Andrew J. Shuck, Joseph S. Jewell, Jonathan Poggie, Andrew N. Bustard, Thomas J. Juliano, Nicholas J. Bisek

Publications

The design of an inward-turning, high-speed, three-dimensional streamline traced intake is presented from osculating axisymmetric theory. To satisfy the osculating intake design criteria, a stitched Busemann diffuser and Internal Conical Flow-A solution is used as the basic isentropic compressive streamline. This new contour provides efficient compression, high flow uniformity, and straight leading edge shocks of equal strength. Additionally, a novel method for constructing the inlet cowl is presented. The combined process leads to a new method of high-speed intake design. A generic shape-transitioned intake is constructed and named the Indiana Inlet for the Indiana universities that contributed to the project. …

Investigation Of Microstructurally Dependent Mechanical Properties Of Cold Sprayed Copper Using Correlative Microscopy, Quintin Otto

UNF Graduate Theses and Dissertations

This project employs multi-instrument materials characterization to analyze material made with the “Cold Spray” additive manufacturing process. Cold spray is an emerging additive manufacturing technique with unique benefits resulting from its low temperature adhesion process induced by plastic deformation. Metallic powder collides at high speeds creating three dimensional materials and coatings without the need for melting. Copper cold sprayed specimens were analyzed using a series of imaging techniques to characterize the microstructure at varying levels of detail and magnification. Scanning electron microscopy and electron back scattered diffraction were paired with microhardness testing to generate a correlative comparison between microstructure and …

Analysis Of Pervious Oyster Shell Habitat (Posh) Unit Performance Using Computational Fluid Dynamics, Lauren E. Cope

UNF Graduate Theses and Dissertations

In recent years, pervious oyster shell habitat (POSH) units have been developed and deployed as part of living shoreline projects in Northeast Florida. POSH units are modular artificial oyster reef structures made from cement and recycled oyster shells. POSH units aim to attenuate wave energy, trap sediment, restore salt marsh habitat, and improve oyster recruitment. Previous studies demonstrated the units’ ability to attract oyster larvae and reduce shoreline bed stress in some areas. This paper looks to further understand the effect of POSH unit placement on bed stress under boat wake conditions using computational fluid dynamics (CFD). Results indicated that …

Frequency Analysis Of A New Empirical Model To Predict Underwater Transmission Loss During Impact Pile Driving, Mariam S. Makoleo

UNF Graduate Theses and Dissertations

Over the years, anthropogenic noise generated by pile driving activities has increased, posing a significant concern for marine organisms and their ecosystems. This study aims to entail a comprehensive frequency analysis of a new empirical model to predict underwater transmission loss during impact pile driving. To achieve this objective, extensive data collection was undertaken, and spectral and frequency analyses were conducted to examine the frequency content and attenuation patterns of the sound. The results of the study reveal that sound attenuation is frequency-dependent. Notably, low frequencies, typically below 100 Hz, and very high frequencies, approximately 10 kHz, were found to …

Analyzing Physiological Signals During The Menstrual Cycle: Introducing An Application Of Circular Statistics, Krystal D. Sides

UNF Graduate Theses and Dissertations

Physiological signals are used in engineering and the sciences to determine the state of functionality of certain physiological systems such as the human endometrium. Many women use the basal body temperature method to track ovulation, or their fertile window. However, temperature tracking alone is subject to environmental factors. Non-invasive wearable devices can be tools in recording cycle-related physiological features relevant to women’s health research. This research uses the Empatica E4 wristband to track changes in the physiological features during sleep across the menstrual cycle of ovulating and non-ovulating females. Due to the cyclic nature of menstrual cycles, analytic solutions to …

Sustainable Transportation: Behavioral Analysis Of Working-From-Home And Electric Vehicles Adoption, Zeinab Bayati

UNF Graduate Theses and Dissertations

Sustainable transportation plays a crucial role in mitigating environmental impacts, and this study examines two key aspects, namely working from home (WFH) and the adoption of electric vehicles (EVs), in the context of promoting sustainable practices.

The first part of this thesis focuses on how people's perceptions towards working from home have changed as a result of their experiences during COVID-19. To analyze these changes, a random parameter logit (RPL) model is developed based on a nationwide public dataset collected during the pandemic in the United States. Dependent variable of the model is constructed through comparing data from the first …

Ovulation Prediction Using Random Forest Algorithm On Physiological Data, Kimberly D. Laynes

UNF Graduate Theses and Dissertations

Human infertility rates are on the rise -- studies have shown that one in every four women have trouble conceiving and every year those rates are rising [Halleran22]. This trend motivates procedures such as in-vitro fertilization (IVF) and intrauterine insemination (IUI) to produce a pregnancy. Such procedures are not only intricate and expensive but also carry potential unintended consequences for women's physical and mental well-being. A more profound comprehension of the menstrual cycle and its multiple phases, particularly detecting the ovulation period itself, promotes optimized treatment outcomes and reduces associated risks. To facilitate ovulation detection, new sensing technologies built into …

Predicting Florida's Extreme Wind Events: A Deep Learning Approach, Irene Josephat Byemerwa

UNF Graduate Theses and Dissertations

Extreme wind events, such as hurricanes and tropical storms, have devastating impacts on infrastructure, economy, and public safety in Florida. Traditional predictive methods, linear regression, logistic regression, and autoregressive integrated moving-average (ARIMA) models have limitations in accounting for non-stationarity and nonlinearity in meteorological data, leading to less accurate predictions. The primary objective of this study is to leverage the capabilities of deep learning algorithms, specifically, Feedforward Neural Networks (FFNNs), to develop a predictive model that outperforms traditional predictive methods in forecasting extreme wind events in Florida. The deep learning model was trained, validated, and tested using historical wind speed data …

Development Of High Kinetic Inductance Superconducting Nanowire Devices On High Permittivity Strontium Titanate Substrates, Jamie Timmons

UNF Graduate Theses and Dissertations

This thesis involves the fabrication and characterization of devices made from two different superconducting materials: yttrium barium copper oxide (YBCO), a high-TC complex oxide, and niobium nitride (NbN), a low-TC transition metal nitride. Both types of devices are fabricated on strontium titanate substrates, which provides a good lattice match to YBCO and also an extremely large permittivity at low temperature. We demonstrate that wet etching of YBCO thin films via bromine can be a viable microfrabriation technique for the material. Using approximately 35 nm thick epitaxially grown YBCO on an STO substrate, we were able to fabricate YBCO “microwires” with …

Development Of Practical Assessment Techniques For Sinkhole Potential In Florida Based On Sinkhole Vulnerability Indices, Sylvia Pesha

UNF Graduate Theses and Dissertations

Sinkholes are natural geohazards prevalent in Florida's distinctive karst geology, posing risks to public safety, infrastructure, and groundwater integrity. Considering the increasing frequency of sinkhole occurrences in Florida due to land development in vulnerable soils, understanding the potential for sinkhole occurrence can aid in the identification of high-risk locations and inform effective mitigation strategies. Researchers have developed three point-based indices to be used when assessing the vulnerability a project site has to sinkhole formation based on the encountered subsurface conditions. Engineers have historically used an index based on the subsurface layer thicknesses, called the Raveling Index (RI). In recent years, …

Synthesis Of High-Temperature Ybco Superconductors, Simon Ji , '23

Senior Theses, Projects, and Awards

Superconductors are a fascinating class of materials that seem to defy physics. For my project, I attempted to create one of the most famous types of superconductor, Yttrium Barium Copper Oxide (YBCO), using commonly available chemicals found online and equipment that already exists on campus. This report gives a short description of the theory behind superconductors, and outlines the synthesis procedures I followed that involved citrate pyrolysis and high-temperature treatment using a tube furnace. I succeeded in creating YBCO samples that exhibited superconducting behaviors, and also designed a small magnetic track that can be used for demonstration purposes.

Max Fit Event Management With Salesforce, Akshay Dagwar

Electronic Theses, Projects, and Dissertations

MAX FIT Gym is looking for an event management software program to help manage activities very efficiently, along with attendees and environmental statistics. The event management program is developed and deployed using the Salesforce platform. MAX FIT can efficiently create, edit, and remove events and send email alerts to clients. This task operated on opportunities captured under MAX FIT, including all clients, and prepared information in the Salesforce cloud. This also includes product inventory with various varieties of protein products, and business owners can also add more products to their inventory. In the event management program, the event addresses within …

Breast Density Classification Using Deep Learning, Conrad Thomas Testagrose

UNF Graduate Theses and Dissertations

Breast density screenings are an accepted means to determine a patient's predisposed risk of breast cancer development. Although the direct correlation is not fully understood, breast cancer risk increases with higher levels of mammographic breast density. Radiologists visually assess a patient's breast density using mammogram images and assign a density score based on four breast density categories outlined by the Breast Imaging and Reporting Data Systems (BI-RADS). There have been efforts to develop automated tools that assist radiologists with increasing workloads and to help reduce the intra- and inter-rater variability between radiologists. In this thesis, I explored two deep-learning-based approaches …

Energy-Efficient Hmac For Wireless Communications, Cesar Enrique Castellon Escobar

UNF Graduate Theses and Dissertations

This thesis introduces the Farming Lightweight Protocol (FLP) optimized for energy-restricted environments that depend upon secure communication, such as multi-robot information gathering systems within the vision of ``smart'' agriculture. FLP uses a hash-based message authentication code (HMAC) to achieve data integrity. HMAC implementations, resting upon repeated use of the SHA256 hashing operator, impose additional resource requirements and thus also impact system availability. We address this particular integrity/availability trade-off by proposing an energy-saving algorithmic engineering method on the internal SHA256 hashing operator. The energy-efficient hash is designed to maintain the original security benefits yet reduce the negative effects on system availability. …

Analysis Of Underwater Noise Due To Pile Driving In Florida Using Individual Hammer Blows, Consolatha Constantine Mushi

UNF Graduate Theses and Dissertations

In recent years, the potential impact on marine organisms of sound waves generated by pile driving has become a growing concern. Previous research in this field has predominantly relied upon single-strike averages to analyze underwater sound data. However, it was unclear from these analyses if or how much attenuation may vary during typical pile drives. This study involved collecting sound data from multiple locations during a given pile driving operation at the same time and used these data to analyze sound decay from each hammer blow individually. In addition to this, computational fluid dynamics (CFD) was used to better understand …

Modified Reactive Sputter Deposition Of Titanium Nitride Thin Films Via Hipims With Kick-Pulse And Improvement Of The Structure-Zone Model, Andrew Miceli

UNF Graduate Theses and Dissertations

Direct current (DC) and radio frequency (RF) sputtering methods have been commonplace in industry for several decades and widely studied in literature. Hard films of nitrides, such as titanium nitride (TiN), have been deposited using reactive DC sputtering onto cutting tools and medical devices extensively as well. For these applications, the films require excellent adhesion, high density, and high hardness. High-Power Impulse Magnetron Sputtering (HIPIMS) has emerged over the last several years as a method to produce films with increased density and mechanical properties. Process-structure-property relationships for reactive HIPIMS are not yet well developed. Additionally, conventional HIPIMS suffers from relatively …

Extracting Road Surface Marking Features From Aerial Images Using Deep Learning, Michael Kimollo

UNF Graduate Theses and Dissertations

The traffic and roadway safety agencies spend significant efforts each year collecting roadway data, including lane configurations and other road surface marking data, such as areas with school zone markings, sidewalks, left turns, right turns, bicycle lanes, etc., for safety analysis and planning purposes. The current manual data collection methods pose significant operational and quality control challenges as they are costly and prone to errors. In addition to that the manual data collection is labor intensive and takes too much time involving high equipment costs, questionable data accuracy guarantees, and concerns about the safety of the crew.

This study aims …

Investigation On The Influence Of Augmented Reality Adoption And Cybersecurity In The Architecture, Engineering And Construction Industry, Kavyaa Boopathy

UNF Graduate Theses and Dissertations

Augmented Reality (AR) applications and the digitization of Architecture, Engineering, and Construction (AEC) industry processes, such as the online building permit process (BPP), have introduced new developments that simplifies tasks, and enhanced data accessibility for stakeholders. This created a digital landscape where sensitive information and critical processes are intertwined, making them vulnerable to cyber-attacks. Existing studies and frameworks on a) AR adoption doesn’t provide essential information (e.g., material availability and costs from different suppliers) and AR features to cater to the diverse needs of different stakeholders. b) threat modeling requires a domain and context specific need investigation, process exploration, critical …

Exploring Of User Experience And Evaluating Mobility Benefits Of Micromobility Systems And Golf Carts: Case Study Of Florida, Kabhabhela C. Bukuru

UNF Graduate Theses and Dissertations

Micromobility devices and golf carts (GCs)/Low speed vehicles(LSVs) are urban transportation solutions that provide short-distance travel options, including first- and last-mile trips. They mostly operate at speeds of 15 mi/h to 35 mi/h. The micromobility devices include e-scooters and e-bikes. The micromobility devices and golfcarts are increasing rapidly in the transportation system, and thus, it is necessary to explore their various factors. The objective of this study is to explore the user experience and evaluate the mobility benefits of the micromobility systems in Florida.

A survey was conducted in various cities with a substantial user base of micromobility devices. Various …

When Intercepting Moving Targets, Mid-Movement Error Corrections Reflect Distinct Responses To Visual And Haptic Perturbations, Pablo Gonzalez Polanco, Leigh A. Mrotek, Kristy A. Nielson, Scott A. Beardsley, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

We examined a key aspect of sensorimotor skill: the capability to correct performance errors that arise mid-movement. Participants grasped the handle of a robot that imposed a nominal viscous resistance to hand movement. They watched a target move pseudo-randomly just above the horizontal plane of hand motion and initiated quick interception movements when cued. On some trials, the robot's viscosity or the target's speed changed without warning coincident with the GO cue. We fit a sum-of-Gaussians model to mechanical power measured at the handle to determine the number, magnitude, and relative timing of submovements occurring in each interception attempt. When …

Aortic Remodeling Kinetics In Response To Coarctation-Induced Mechanical Perturbations, Arash Ghorbannia, Mehdi Maadooliat, Ronald K. Woods, Said H. Audi, Brandon J. Tefft, Claudio Chiastra, El Sayed H. Ibrahim, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

Background: Coarctation of the aorta (CoA; constriction of the proximal descending thoracic aorta) is among the most common congenital cardiovascular defects. Coarctation-induced mechanical perturbations trigger a cycle of mechano-transduction events leading to irreversible precursors of hypertension including arterial thickening, stiffening, and vasoactive dysfunction in proximal conduit arteries. This study sought to identify kinetics of the stress-mediated compensatory response leading to these alterations using a preclinical rabbit model of CoA.

Methods: A prior growth and remodeling (G&R) framework was reformulated and fit to empirical measurements from CoA rabbits classified into one control and nine CoA groups of various severities …

Flying Blind: Exploring The Visual Cues Used By Helicopter Pilots In Degraded Visual Environments, Brandon Dreslin, Molly C. Mersinger, Shivani Patel, Alex Chaparro

Publications

Helicopter pilots rely on visual cues from the environment and instrument displays during critical phases of flight – particularly final approach and landing – to safely land. However, the specific visual cues pilots rely on and how they integrate those cues to make anticipatory inceptor inputs or corrections are not well understood. Importantly, those cues may be degraded under nighttime and brownout/whiteout conditions where the downwash of a helicopter’s rotors cause loose dirt/snow to be projected into the air, resulting in the obfuscation of the pilot’s vision outside the aircraft. The lack of visual cues in these conditions means that …

A Framework For Assessing Environmental Incidents In Coastal Areas: A Case Study In The Southeastern Coastal Area Of Vietnam, Cuong Le Tan, Phuoc Nguyen Van, Quan Nguyen Hong, Loan Tran Thi Diem, Minh Tran Thanh

Applied Environmental Research

As developing dynamic regions, coastal areas have a high potential for environmental incidents, especially chemical spills, which may permanently threaten livelihoods and coastal ecosystems. Establishing an appropriate methodological framework for assessing environmental incidents in coastal areas, ensuring increased predictability and minimising potential consequences is a trend of interest to scientists. In this study, the environmental risk assessment model was applied to develop a framework for assessing environmental incidents in coastal areas due to chemical spills from the mainland based on hazard, exposure and vulnerability factors (i.e., sensitivity and adaptability). Using the multiple criteria decision-making (MCDM) method approach, suitable criteria, their …

Life Cycle Assessment Of Plastic Resin: A Case Study Of The Petrochemical Industry In Thailand For The Production Of Hdpe Resin, Natthapong Wichaiutcha, Abhishek Dutta, Orathai Chavalparit

Applied Environmental Research

Life cycle sustainability is an important tool for assessing product performance based on the three pillars of environment, economy and society. This study examined the life cycle impact, cost and social implications of high-density polyethylene (HDPE) resin. Environmental assessment revealed nonrenewable energy as the greatest impact followed by carcinogens, respiratory inorganics and global warming while economically, the operational cost of HDPE resin production was significantly highest. The social impact assessment following the United Nation Environmental Programme (UNEP)/ Society of Environmental Toxicology and Chemistry (SETAC) guidelines demonstrated optimal performance for all indicators except for gender ratio and disabled employee criteria which …

Optimization Of Vanillin Production From Lignin Using Catalytic Depolymerization Over A Cuo/Al2o3 Catalyst, Sirawit Sangnak, Arthit Neramittagapong, Sutasinee Neramittagapong, Somnuk Theerakulpisut, Pongsert Sriprom

Applied Environmental Research

The optimal conditions for vanillin production from lignin depolymerization using CuO/Al2O3 catalysts were determined by combining Box-Behnken design (BBD) and response surface methodology (RSM). Independent variables, including temperature (80–140 °C), NaOH loading (0.5–1.5 g), time (30–90 min), and catalyst weight (0.5–1.5 g), were investigated to determine the optimal conditions, with the concentration of vanillin being the dependent variable. A CuO/Al2O3 catalyst was prepared by impregnation method. The vanillin obtained from the reaction was analyzed using high-performance liquid chromatography (HPLC). The maximum obtained vanillin concentration of 59.14 mg·L-1 was achieved with a temperature of 80 °C, a reaction time of 90 …

Utilizing Wasteaware Benchmark Indicators To Improve Municipal Solid Waste Management In Northern Thailand, Sujitra Vassanadumrongdee, Ridthipat Kallayanapattharasit, Arisara Lekkham, Pattayaporn Unroj

Applied Environmental Research

Primarily responsible for waste collection and disposal, local governments in northern Thailand face significant obstacles in managing waste. Mixing infectious, hazardous and general waste, over-utilizing incinerators and implementing environmentally improper disposal methods all contribute to burgeoning volumes of waste with adverse environmental and health impacts. The objectives of this study are to use the Wasteaware benchmark indicators (WABIs) to assess the effectiveness and sustainability of the waste management of Wiengthoeng Sub-district Municipality (WSM), to identify advantages and disadvantages of its system and offer fact-based recommendations for improvement. Pertinent data was obtained through interviews of governmental authorities, community members and private …

Estimation Of Respiratory Disease Burden Attributed To Particulate Matter From Biomass Burning In Northern Thailand Using 1-Km Resolution Maiac-Aod, Anuttara Hongthong, Kampol Nanthapong, Thongchai Kanabkaew

Applied Environmental Research

The upper northern Thailand suffers from air pollution due to open burning, which has been known for a long time. It was also found that different respiratory diseases were attributed to air pollution, especially particulate matter. This study estimated the health impacts attributed to PM10 between 2014 and 2016 using the burden of disease in terms of the disability adjusted life year (DALYs). The spatial correlation was evaluated based on applicable remote sensing data using the geographically weighted regression (GWR) model. The average measured PM10 concentrations for the summer and annual periods between 2014 and 2016 were 73 and 89 …

Microplastic Contamination In The Coastal Environment: A Case Study From The Mae Klong River, Samut Songkhram, Pattraporn Chaisanguansuk, Suphak Ploenbuppa, Thitiphan Assawincharoenkij, Sumet Phantuwongraj, Akkaneewut Jiraphinyakul

Applied Environmental Research

To investigate the microplastic contamination in the coastal area in Samut Songkhram, we collected sediment samples from six locations in mangrove forests along the Mae Klong River estuary (MK) and the nearby Khlong Khon canal (KK). The microplastics were extracted by ZnCl2 density separation and subsequently H2O2 digestion. The microplastic abundance and physical properties, including their size, color, and shape, were determined under the binocular microscope. The selected microplastic samples were analyzed by µ-FTIR spectroscopy to identify their polymer types. Microplastic concentrations were c. 580 and 1690 items kg-1 d.w. in the samples from MK and KK. The lower microplastic …