Engineering Commons^™

Modeling Coastal Vulnerability Of The St. Johns River And Northeastern Florida Shorelines, Madison E. Heppe

UNF Graduate Theses and Dissertations

Coastal and riverine communities, with anthropogenic congestion and natural and economic resources, are vulnerable to climate change impacts including rising sea levels and increasing severity and frequency of storms. Coastal habitats are being increasingly recognized as natural infrastructure that provides resiliency against these stressors. However, few studies have analyzed coastal vulnerability at landscape scale with finely resolved spatial data that account for habitats and demographics. The purpose of this study is to map the coastal vulnerability of the St. Johns River and adjacent Northeastern Florida Atlantic shoreline within the St. Johns River Water Management District. Unique to this study is …

Energy Considerations In Blockchain-Enabled Applications, Cesar Enrique Castellon Escobar

UNF Graduate Theses and Dissertations

Blockchain-powered smart systems deployed in different industrial applications promise operational efficiencies and improved yields, while mitigating significant cybersecurity risks pertaining to the main application. Associated tradeoffs between availability and security arise at implementation, however, triggered by the additional resources (e.g., memory, computation) required by each blockchain-enabled host. This thesis applies an energy-reducing algorithmic engineering technique for Merkle Tree root and Proof of Work calculations, two principal elements of blockchain computations, as a means to preserve the promised security benefits but with less compromise to system availability. Using pyRAPL, a python library to measure computational energy, we experiment with both the …

Thoughts On The Future Of Higher Education In The Uk: A Personal View With A Historical Context, Jonathan Blackledge

Articles

Before the effect of the COVID-19 Pandemic, there had been continued debate about the future of Higher Education (HE) in the UK. It is now accepted that the effect of the pandemic will have a long-lasting effect on HE in the UK and elsewhere. This paper addresses the changes that are currently taking place, based on a strategy that aims to develop a future knowledge-based economy, following the UK governments 2019 landmark review of HE. It explores the underlying parallels between the current situation and certain historical events that catalysed the development of a new approach to HE in the …

Super Twisting Sliding-Mode Control Of Dvr With Frequency-Adaptive Brockett Oscillator, Samet Biricik, Hasan Komurcugil, Hafiz Ahmed, Ebrahim Babaei

Articles

This paper presents a super twisting sliding mode control (ST-SMC) for single-phase dynamic voltage restorers (DVRs). Unlike the conventional first-order sliding mode controller, the proposed ST-SMC technique eliminates the need for differentiating the compensation voltage in the sliding surface function while keeping the merits of first-order SMC. As a consequence of employing ST-SMC, a continuous control signal is achieved from which the pulse width modulation (PWM) signals can be generated. In this case, the inverter operates at constant switching frequency. The stability analysis of ST-SMC is also presented. The reference compensation voltage needed in ST-SMC is estimated by using Brockett …

The Discrete Fourier Transform - A Practical Approach, David Dorran

Articles

These notes on the Discrete Fourier Transform include numerous practical examples that make use of audio signals.

Analyzing Benefits Of Connected Vehicle Technologies During Incidents On Freeways And Diversion Strategies Implementation: A Microsimulation-Based Case Study Of Florida's Turnpike, Francisca P. Kasubi

UNF Graduate Theses and Dissertations

The full utilization of connected vehicles (CVs) is highly anticipated to become a reality soon. As CVs become increasingly prevalent in our roadway network, connected technologies have enormous potential to improve safety. This study conducted a microscopic simulation to quantify the benefits of CVs in improving freeway safety along a 7.8-mile section on Florida’s Turnpike (SR-91) system. The simulation incorporated driver compliance behavior in a CV environment. The simulation was implemented via an existing VISSIM network model partially developed by the Florida Department of Transportation (FDOT). In addition, the study analyzed how CVs would assist in detour operations as a …

Examination Of Driver Visual And Cognitive Responses To Billboard Elicited Passive Distraction Using Eye-Fixation Related Potential, Yongxiang Wang, William Clifford, Charles Markham, Catherine Deegan

Articles

Distractions external to a vehicle contribute to visual attention diversion that may cause traffic accidents. As a low-cost and efficient advertising solution, billboards are widely installed on side of the road, especially the motorway. However, the effect of billboards on driver distraction, eye gaze, and cognition has not been fully investigated. This study utilises a customised driving simulator and synchronised electroencephalography (EEG) and eye tracking system to investigate the cognitive processes relating to the processing of driver visual information. A distinction is made between eye gaze fixations relating to stimuli that assist driving and others that may be a source …

In Depth Characterisation Of The Biomolecular Coronas Of Polymer Coated Inorganic Nanoparticles With Differential Centrifugal Sedimentation, André Perez-Potti, Hender Lopez, Beatriz Pelaz, Abuelmagd Abdelmonem, Mahmoud G. Soliman, Ingmar Schoen, Philip M. Kelly, Kenneth A. Dawson, Wolfgang J. Parak, Zeljka Krpetic, Marco P. Monopoli

Articles

Advances in nanofabrication methods have enabled the tailoring of new strategies towards the controlled production of nanoparticles with attractive applications in healthcare. In many cases, their characterisation remains a big challenge, particularly for small-sized functional nanoparticles of 5 nm diameter or smaller, where current particle sizing techniques struggle to provide the required sensitivity and accuracy. There is a clear need for the development of new reliable characterisation approaches for the physico-chemical characterisation of nanoparticles with significant accuracy, particularly for the analysis of the particles in the presence of complex biological fluids. Herein, we show that the Differential Centrifugal Sedimentation can …

Beyond Charge Transfer: The Impact Of Auger Recombination And Fret On Pl Quenching In An Rgo-Qds System, Anton Babaev, Anastasiia Sokolova, Kevin Berwick, Alexander Baranov, Anatoly Fedorov, Aleksandr P. Litvin

Articles

PL intensity quenching and the PL lifetime reduction of fluorophores located close to gra‐ phene derivatives are generally explained by charge and energy transfer processes. Analyzing the PL from PbS QDs in rGO/QD systems, we observed a substantial reduction in average PL lifetimes with an increase in rGO content that cannot be interpreted solely by these two processes. To explain the PL lifetime dependence on the rGO/QD component ratio, we propose a model based on the Auger recombination of excitations involving excess holes left in the QDs after the charge transfer process. To validate the model, we conducted additional experiments …

Using Case Studies In Engineering Ethics Education: The Case For Immersive Scenarios Through Stakeholder Engagement And Real Life Data, Diana Adela Martin, Eddie Conlon, Brian Bowe

Articles

Our contribution is part of a broader study conducted in cooperation with the national accreditation body Engineers Ireland that examined the conceptualisation and education of ethics in engineering programmes in Ireland. The paper is a qualitative examination of the use of case studies in engineering ethics education and includes 23 engineering programmes from 6 higher education institutions in Ireland. The qualitative study aims to determine (RQ1) how cases are selected, (RQ2) the goals envisioned for engineering ethics case instruction, (RQ3) the characteristics of the scenarios employed and (RQ4) the preferred application by instructors. A first finding notes the diverse set …

Day-Ahead Offering Strategy In The Market For Concentrating Solar Power Considering Thermoelectric Decoupling By A Compressed Air Energy Storage, Shitong Sun, S. Mahdi Kazemi-Razi, Lisa G. Kaigutha, Mousa Marzband, Hamed Nafisi, Ameena Saad Al-Sumaiti

Articles

Due to limited fossil fuel resources, a growing increase in energy demand and the need to maintain positive environmental effects, concentrating solar power (CSP) plant as a promising technology has driven the world to find new sustainable and competitive methods for energy production. The scheduling capability of a CSP plant equipped with thermal energy storage (TES) surpasses a photovoltaic (PV) unit and augments the sustainability of energy system performance. However, restricting CSP plant application compared to a PV plant due to its high investment is a challenging issue. This paper presents a model to assemble a combined heat and power …

User Guide For Dust Modeling Using Cmaq 5.3.1 And Wrf 4.2.1, Zachary D. Lawless, Ariel S. Cable, Cameron B. Van Dyke, Bradley R. Adams

Faculty Publications

Researchers at Brigham Young University (BYU) have developed a software framework for modeling dust emission and transport using the Community Multiscale Air Quality (CMAQ) modeling system in conjunction with the Weather Research and Forecasting (WRF) model and other utility programs. This framework uses meteorological data, land use data, and soil properties to predict dust concentrations for a specified area. This User Guide describes the start-to-finish process required to install and utilize relevant software to calculate and visualize dust concentrations. Note that the examples and figures provided in the guide are specific to Utah in the western United States, where this …

Mentoring Prospective Engineering Students Through The After School Program "Girls In Engineering" Focused On Building An Underwater Remotely Operated Vehicle, Vukica M. Jovanović, Deborah Marshall, Jeff Warren Larson Jr., Abdul Rahman Badawi, Neil R. Stclair, Otilia Popescu, Murat Kuzlu, Petros J. Katsioloudis, Linda Vahala, Michael Anthony Crespo

Engineering Technology Faculty Publications

A number of studies by engineering education researchers have pointed out that all-female teams, rather than mixed teams, result in better forms of participation and interaction in engineering related after-school programs and clubs. In particular, for after-school programs or clubs that form in response to a STEM competition, all-female teams have better chances of developing. One such competition, which will be discussed in this paper, is a regional Marine Advanced Technology Education (MATE) competition in which students from Blind_Review High School have been participating for many years.For each year’s competition, an all-female team of students enrolled in the Career and …

A Surrogate Weather Generator For Estimating Natural Gas Design Day Conditions, David J. Kaftan, George Corliss, Richard J. Povinelli, Ronald H. Brown

Electrical and Computer Engineering Faculty Research and Publications

Natural gas customers rely upon utilities to provide gas for heating in the coldest parts of winter. Heating capacity is expensive, so utilities and end users (represented by commissions) must agree on the coldest day on which a utility is expected to meet demand. The return period of such a day is long relative to the amount of weather data that are typically available. This paper develops a weather resampling method called the Surrogate Weather Resampler, which creates a large dataset to support analysis of extremely infrequent events. While most current methods for generating weather data are based on simulation, …

Unsteady-State Contact Angle Hysteresis During Droplet Oscillation In Capillary Pores: Theoretical Model And Vof Simulation -- Supporting Information, Chao Zeng, Wen Deng, Lichun Wang

Research Data

Contact angle hysteresis (CAH) is a critical phenomenon that could significantly affect the fate of immiscible bubbles/droplets in vadose zones, nonaqueous phase liquid contaminated aquifers, and saline aquifers for CO₂ sequestration in terms of infiltration patterns and residual trapping mechanisms. When external physical impacts such as oscillatory excitation or pulse forcing are applied, it could result in pinned oscillation of droplets due to this CAH. Conventional steady-state analysis of contact angle could underestimate CAH. As the first time to take unsteady-state effect into consideration, a hydrodynamic analysis is developed in this study to address the unsteady-state CAH theoretically, and …

Stress-State Dependency Of The Deformation Ratio Of Quasi-Elastic Granular Soils Under Cyclic Loading -- Supporting Information, Pingxin Xia, Longtan Shao, Wen Deng

Research Data

Poisson’s ratio, besides its transverse-axial strain ratio definition, also plays a significant role in traditional elastic theory as an elastic constant. However, this elastic role of Poisson’s ratio faces a challenge when applied to quasi-elastic granular soils. A so-called “deformation ratio” is therefore introduced and measured in this paper for quasi-elastic granular soils. With the same definition of the transverse-axial strain ratio as Poisson’s ratio, the stress-state dependency of the deformation ratio and the break-down of conversion relationship of elastic constants are investigated under cyclic triaxial tests. The results show that Poisson’s ratio is consistent with deformation ratio only in …

Plant Identification In A Combined-Imbalanced Leaf Dataset -- Images, Viraj K. Gajjar, Anand Nambisan, Kurt Louis Kosbar

Research Data

Plant identification has applications in ethnopharmacology and agriculture. Since leaves are one of a distinguishable feature of a plant, they are routinely used for identification. Recent developments in deep learning have made it possible to accurately identify the majority of samples in five publicly available leaf datasets. However, each dataset captures the images in a highly controlled environment. This paper evaluates the performance of EfficientNet models, B1 to B6, and several other convolutional neural network (CNN) architectures when applied to a combination of the LeafSnap, Middle European Woody Plants 2014, Flavia, Swedish, and Folio datasets. To normalize the impact of …

Underestimation Bias And Underfitting In Machine Learning, Padraig Cunningham, Sarah Jane Delany

Conference papers

. Often, what is termed algorithmic bias in machine learning will be due to historic bias in the training data. But sometimes the bias may be introduced (or at least exacerbated) by the algorithm itself. The ways in which algorithms can actually accentuate bias has not received a lot of attention with researchers focusing directly on methods to eliminate bias - no matter the source. In this paper we report on initial research to understand the factors that contribute to bias in classification algorithms. We believe this is important because underestimation bias is inextricably tied to regularization, i.e. measures to …

Cybersecurity Leaders: Knowledge Driving Human Capital Development, Sharon L. Burton

Publications

Cybersecurity leaders must be able to use critical reading and thinking skills, exercise judgment when policies are not distinct and precise, and have the knowledge, skills, and abilities to tailor technical and planning data to diverse customers’ levels of understanding. Ninety-three percent of cybersecurity leaders do not report directly to the chief operating officer. While status differences influence interactions amid groups, attackers are smarter. With the aim of protecting organizations and reducing risk, knowledge about security must increase. Understanding voids are costly and increased breach chances are imminent. Burning questions exist. What are needed technological learnings for cybersecurity leaders to …

Fmri Feature Extraction Model For Adhd Classification Using Convolutional Neural Network, Senuri De Silva, Sanuwani Udara Dayarathna, Gangani Ariyarathne, Dulani Meedeniya, Sampath Jayarathna

Computer Science Faculty Publications

Biomedical intelligence provides a predictive mechanism for the automatic diagnosis of diseases and disorders. With the advancements of computational biology, neuroimaging techniques have been used extensively in clinical data analysis. Attention deficit hyperactivity disorder (ADHD) is a psychiatric disorder, with the symptomology of inattention, impulsivity, and hyperactivity, in which early diagnosis is crucial to prevent unwelcome outcomes. This study addresses ADHD identification using functional magnetic resonance imaging (fMRI) data for the resting state brain by evaluating multiple feature extraction methods. The features of seed-based correlation (SBC), fractional amplitude of low-frequency fluctuation (fALFF), and regional homogeneity (ReHo) are comparatively applied to …

Smart Parking Systems: Reviewing The Literature, Architecture And Ways Forward, Can Biyik, Zaheer Allam, Gabriele Pieri, Davide Moroni, Muftah O' Fraifer, Eoin O' Connell, Stephan Olariu, Muhammad Khalid

Computer Science Faculty Publications

The Internet of Things (IoT) has come of age, and complex solutions can now be implemented seamlessly within urban governance and management frameworks and processes. For cities, growing rates of car ownership are rendering parking availability a challenge and lowering the quality of life through increased carbon emissions. The development of smart parking solutions is thus necessary to reduce the time spent looking for parking and to reduce greenhouse gas emissions. The principal role of this research paper is to analyze smart parking solutions from a technical perspective, underlining the systems and sensors that are available, as documented in the …

Parallel Anisotropic Unstructured Grid Adaptation, Christos Tsolakis, Nikos Chrisochoides, Michael A. Park, Adrien Loseille, Todd Michal

Computer Science Faculty Publications

Computational fluid dynamics (CFD) has become critical to the design and analysis of aerospace vehicles. Parallel grid adaptation that resolves multiple scales with anisotropy is identified as one of the challenges in the CFD Vision 2030 Study to increase the capacity and capability of CFD simulation. The study also cautions that computer architectures are undergoing a radical change, and dramatic increases in algorithm concurrency will be required to exploit full performance. This paper reviews four different methods to parallel anisotropic grid adaptation. They cover both ends of the spectrum: 1) using existing state-of-the-art software optimized for a single core and …

Combining Cryo-Em Density Map And Residue Contact For Protein Secondary Structure Topologies, Maytha Alshammari, Jing He

Computer Science Faculty Publications

Although atomic structures have been determined directly from cryo-EM density maps with high resolutions, current structure determination methods for medium resolution (5 to 10 Å) cryo-EM maps are limited by the availability of structure templates. Secondary structure traces are lines detected from a cryo-EM density map for α-helices and β-strands of a protein. A topology of secondary structures defines the mapping between a set of sequence segments and a set of traces of secondary structures in three-dimensional space. In order to enhance accuracy in ranking secondary structure topologies, we explored a method that combines three sources of information: a set …

See-Trend: Secure Traffic-Related Event Detection In Smart Communities, Stephan Olariu, Dimitrie C. Popescu

Computer Science Faculty Publications

It has been widely recognized that one of the critical services provided by Smart Cities and Smart Communities is Smart Mobility. This paper lays the theoretical foundations of SEE-TREND, a system for Secure Early Traffic-Related EveNt Detection in Smart Cities and Smart Communities. SEE-TREND promotes Smart Mobility by implementing an anonymous, probabilistic collection of traffic-related data from passing vehicles. The collected data are then aggregated and used by its inference engine to build beliefs about the state of the traffic, to detect traffic trends, and to disseminate relevant traffic-related information along the roadway to help the driving public make informed …

Zone Path Construction (Zac) Based Approaches For Effective Real-Time Ridesharing, Meghna Lowalekar, Pradeep Varakantham, Patrick Jaillet

Research Collection School Of Computing and Information Systems

Real-time ridesharing systems such as UberPool, Lyft Line and GrabShare have become hugely popular as they reduce the costs for customers, improve per trip revenue for drivers and reduce traffic on the roads by grouping customers with similar itineraries. The key challenge in these systems is to group the “right” requests to travel together in the “right” available vehicles in real-time, so that the objective (e.g., requests served, revenue or delay) is optimized. This challenge has been addressed in existing work by: (i) generating as many relevant feasible combinations of requests (with respect to the available delay for customers) as …

Flow And Heat Transfer Characteristics Of Turbulent Swirling Impinging Jets [Thesis], Muhammad Ikhlaq

Theses: Doctorates and Masters

Numerous industrial applications rely on impinging jets to impart convective heat and mass transfer in processes ranging from the cooling of electronic devices and gas turbine blades to drying of paper and food products. Conventionally, non-swirling impinging jets have been employed, but some studies have shown that inducing swirl allows better control of uniformity and improved convective fluxes. A better understanding of the underlying physical mechanisms that lead to such behaviour warrants deeper insights into the flow and heat transfer characteristics of impinging jets, both swirling and non-swirling. Whilst important to achieve, the flow field of an impinging jet is …

Experimental And Cfd–Pbm Investigation Of An Agitated Bioreactor Using A Dual Helical Ribbon Impeller, Maryamsadat Amiraftabi

Theses: Doctorates and Masters

Throughout past decades, the management of solid waste by producing methane gas, as a renewable source of energy, has featured as an important research objective. Anaerobic digesters are widely used in countries with environmental initiatives and green approaches, where biogas produced from a bioreactor is a carbon neutral source of energy. Biogas contains 70% methane, 30% CO2 and some other gases. The by-product of an anaerobic digester is solid sludge that can be used as either fertilizer or compost.

Anaerobic digestion biogas plants can benefit industries by adding value to solid organic waste, reducing fossil fuel usage, eliminating solid waste …

Power Network And Smart Grids Analysis From A Graph Theoretic Perspective, Hossein Parast Vand

Theses: Doctorates and Masters

The growing size and complexity of power systems has given raise to the use of complex network theory in their modelling, analysis, and synthesis. Though most of the previous studies in this area have focused on distributed control through well established protocols like synchronization and consensus, recently, a few fundamental concepts from graph theory have also been applied, for example in symmetry-based cluster synchronization. Among the existing notions of graph theory, graph symmetry is the focus of this proposal. However, there are other development around some concepts from complex network theory such as graph clustering in the study.

In spite …

Simultaneous Machining Of Aerospace Structural Materials Using Poly-Drills, Muhammad Aamir

Theses: Doctorates and Masters

Despite the growth of composites and other lightweight materials, aluminium alloys remain an attractive choice for the aerospace industry due to their distinct manufacturing processes, good resistance to fatigue crack growth and superior damage tolerance. In the aerospace industry, the drilling process is widely used among all the machining processes as millions of holes are required to produce riveted and bolted joints in the assembly operation of the aircraft's structures. The major challenges which arise from the drilling of these alloys are characterized by the low hole quality, which might initiate cracks within the airframe structure and reducing their reliability. …

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

This research work was conducted to develop a proposed transparent fluid model to mimic dross formation and dispersion in metal castings during the mold filling process. The major cause for dross formation includes the air entrainment, surface turbulence, and bubbles, which create oxide films inside the molten metal. The oxide films are trapped inside the casting after solidification causing detrimental effects on the mechanical properties of the casting.

The objective of the investigation was to explore the feasibility using phenolic urethane as a transparent fluid material to investigate air entrainment mechanism. The experimentation consists of the following materials: the phenolic …