Engineering Commons^™

Machine Learning Driven Resource Allocation In Edge Cloud, Arslan Qadeer Dr

Dissertations and Theses

Next generation mobile and immersive applications (e.g., Augmented Reality (AR), Virtual Reality (VR), Extended reality (XR)), and Internet of Things (IoTs) provide richer functionalities which possess resource-hungry and real-time constraints. To conserve energy and improve performance of such devices, certain computationally heavy tasks can be executed remotely by offloading them to the back-end cloud (BC) and utilizing its abundant compute resources. However, the long distance between a mobile/IoT device and the BC causes huge network delay, thus, deteriorating the user experience of real-time applications. Edge-cloud (EC) and beyond 5G (B5G) wireless communication are envisioned to cope with the above compute …

Blockchain Framework For Secured On-Demand Patient Health Records Sharing, Meryem Abouali

Dissertations and Theses

As the healthcare industry continues to digitize and share patient data for a better understanding of patient health history, cybersecurity must remain a top priority. However, patient health record (PHR) data is extremely sensitive and faces significant challenges due to its distributed nature across various healthcare facilities and providers, which creates a lack of interoperability among healthcare systems. Most patient health record systems adopt a centralized management structure and deploy PHRs to the cloud, which raises privacy concerns when sharing patient information over a network. Thus, there is a need for a framework that considers patient privacy and data security …

Design And Experimental Observation Of Topological States In Photonic Metasurfaces, Anton Vakulenko

Dissertations and Theses

Topological phases in photonics attract a lot of attention due to their unique properties which allow controlling optical coupling and electromagnetic field distributions in nanostructures. Diverse phenomena supported by photonic topological structures include robust scatter-free waveguiding, an extreme confinement of light, lasing and strong coupling with novel low- dimensional materials. A very convenient integration with on-chip optical devices and also with quantum dots or monolayers of van der Waals materials promise even brighter future for photonic topological insulators as a useful platform for innovative photonic and compact quantum devices.

In the course of my dissertation work, I investigated topological structures …

Lidar Remote Sensing Of Aerosol And Ozone Profiles And Application To Air Quality Studies In New York City Area, Dingdong Li

Dissertations and Theses

Ozone (O₃) and PM2.5 (Particulate Matter with a diameter less than 2.5 μm) are the main pollutants in New York City (NYC) due to high levels of anthropogenic emissions, complex urban meteorology, and regional transport. However, vertical distribution observations are still lacking. This thesis utilizes lidar remote sensing techniques to retrieve the vertical distribution of O₃ and aerosols and study air pollution episodes in the NYC metropolitan area.

The thesis includes three parts. The first part analyzes continuous ceilometer observations of aerosols and atmospheric mixed-layer height (ML). We investigate the vertical, diurnal, and seasonal characteristics of the …

Nonlinear And Time-Modulated Metamaterials: Applications At Microwave Frequencies, Hady Mohammed Saied Sayed Moussa

Dissertations and Theses

Metamaterials (the Greek prefix meta, means beyond) are artificially structured materials that interact with the incoming waves in extraordinary ways, beyond the properties of natural materials, yielding unusual and exotic electromagnetics phenomena. By careful engineering of the material properties, invoking nonlinear elements and/or time-modulating some of the material parameters, linearity and/or time-invariance can be broken in metamaterials, enabling extraordinary wave phenomena that open opportunities for the microwave engineering community, including the creation of nonreciprocal devices, frequency conversion, and more. In this dissertation, we explore, investigate, design, and fabricate metamaterials that open new applications for nonlinearity-based and time-varying devices, particularly in …

An Unmanned Aircraft System For Marking Live Power Lines To Prevent Bird Collisions, Mattheuns D. Pretorius, Lourens Leeuwner, Kaajial Durgapersad, Constant Hoogstad, Peter Beckedahl, Michael D. Michael, Kishaylin Chetty

Human–Wildlife Interactions

Collisions with overhead power lines represent a significant cause of mortality for a number of large bird species worldwide. Certain threatened species are severely impacted by power line collisions, particularly those for which there are no other known significant threats. In South Africa, bird collisions with overhead power line cables, including collisions with phase conductors and shield wires, contribute significantly to annual threatened bird species mortalities associated with Eskom power lines. The most practical mitigation measure is to attach bird anti-collision devices as markers on the cables. Current marking methods involve installations by hand, where linemen are hoisted up to …

Comprehensive Fault Diagnostics And Performance Forecasting Of Wind Turbines Through Condition Monitoring Solutions, Shuo Zhang

Doctoral

The operation and maintenance (O&M) issues of wind turbines (WTs) are challenging because unplanned maintenance, caused by sudden component failures, can bring about durable downtimes and significant revenue losses. It is important to carry out effective fault diagnostics and prognostics schemes under the rapid development of wind power generation. Hence, Condition Monitoring (CM) solutions focus on measurements and detections of high-risk WT components, which could result in high failure rates and long downtimes. Machine Learning (ML) models have been commonly applied in CM to allocate imminent indications of failure or degradation for curtailing the O&M costs of WTs. By way …

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 …

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. …

Constructing Series, Parallel And Mixed Circuits With Lightbulbs And Analyzing Their Behaviors, Adaeze A. Eze

A with Honors Projects

This honors project was an experiment "to find out if the principles of a series, parallel and a mixed circuit still apply under the given condition (varying bulb resistance)."

Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson

Electronic Theses and Dissertations

One of the most significant shifts in the mix of U.S. electricity generation over the past few years has been the rapid expansion of renewable energy resources, especially solar and wind. However, fossil fuels are still necessary to fulfill the world’s energy requirements. Despite efforts to increase the use of renewable energy sources, these sources can be at times unreliable, causing countries around the world to continue to rely on base load units such as coal and natural gas. This decrease in fossil fuels and increase in renewable energy sources presents many complex issues in terms of power system planning, …

Optimizing Battery Performance: Investigating The Long-Term Impacts Of Bidirectional Battery Management Systems On Battery Cells, Drue Nathaniel Haskins

Graduate Research Theses & Dissertations

With the increased use of batteries in everyday life, it is crucial to have a robust and reliable battery system that can continue to power our devices. This paper will investigate the reliability, impact on the batteries, and functionality of the bidirectional battery management system (BMS). The design uses two bidirectional switches for each cell, one in series with the cell and one in parallel with the other bidirectional switch and cell. This will allow the cell to be taken in and out of the circuit for any reason determined by the BMS. Taking the battery in and out of …

An Investigation Of 3.5 Μm Emission In Er3+-Doped Fluorozirconate Glasses Under 638 Nm Laser Excitation, Haiyan Zhao, Ke Tian, Xin Wang, Dejun Liu, Shunbin Wang, Gerald Farrell, Pengfei Wang

Articles

Intense 3.5 μm mid-infrared emission has been achieved in Er3+-doped ZBYA glasses, which is ascribed to the Er3+: 4F9/2→4I9/2 transition. Based on the absorption spectrum of Er3+ ions, a 638 nm laser was utilized to directly pump the upper level (Er3+: 4F9/2) to achieve 3.5 μm emission with enhanced quantum efficiency. Spectroscopic parameters were predicted by Judd-Ofelt theory. The maximum emission cross-section of the Er3+-doped ZBYA glass was estimated to be 5.5×10-22 cm2 at 3496 nm. Additionally, the fluorescence spectra and energy level lifetimes of ZBYA glass samples with different Er3+ ions doping concentrations were also measured. The theoretical and …

Surface Properties, Work Function, And Thermionic Electron Emission Characterization Of Materials For Next-Generation Dispenser Cathodes, Antonio Mantica

Theses and Dissertations--Chemical and Materials Engineering

A dispenser cathode’s ability to thermionically emit electrons is highly dependent on its material properties, especially those of the surface. Understanding the relationship between surface properties and electron emission, therefore, is vital to reach the next generation of the many vacuum electron devices (VEDs) that rely on the physics of electron emission. In the past century, many techniques have been developed to characterize material surfaces and quantify thermionic emission. These techniques are based on a wide range of different physical phenomena, including measuring photoemission via the photoelectric effect, measuring the electrostatic potential between metals in electrical contact, and current collection …

Solid-State Electrolytes For Long Duration Molten Sodium Batteries, Ryan C. Hill

Theses and Dissertations--Chemical and Materials Engineering

Rechargeable batteries have become a staple of modern society, driving the development and expansion of portable electronics and electric vehicles. The long lifetime and high energy density provided by batteries have made them excellent candidates for use in the emerging field of long duration, grid-scale energy storage. However, traditional battery chemistries, such as Li-ion, are not an ideal solution for grid-scale storage, due to high-cost raw materials that are often sourced from volatile markets. Sodium-based batteries are a promising alternative for long duration storage, owing to the domestic abundance of raw materials and energy densities that nearly rival that of …

Opioid Use Disorder Prediction Using Machine Learning Of Fmri Data, A. Temtam, Liangsuo Ma, F. Gerard Moeller, M. S. Sadique, K. M. Iftekharuddin, Khan M. Iftekharuddin (Ed.), Weijie Chen (Ed.)

Electrical & Computer Engineering Faculty Publications

According to the Centers for Disease Control and Prevention (CDC) more than 932,000 people in the US have died since 1999 from a drug overdose. Just about 75% of drug overdose deaths in 2020 involved Opioid, which suggests that the US is in an Opioid overdose epidemic. Identifying individuals likely to develop Opioid use disorder (OUD) can help public health in planning effective prevention, intervention, drug overdose and recovery policies. Further, a better understanding of prediction of overdose leading to the neurobiology of OUD may lead to new therapeutics. In recent years, very limited work has been done using statistical …

A Robust Model For Spot Virtual Machine Bidding In The Cloud Market Using Information Gap Decision Theory (Igdt), Mona Naghdehforoushha, Mehdi Dehghan Takht Fooladi, Mohammed Hossein Rezvani, Mohammad Mehdi Gilanian Sadeghi

Turkish Journal of Electrical Engineering and Computer Sciences

The spot market is one of the most common cloud markets where cloud providers, such as Amazon EC2, rent their surplus computing resources at lower prices in the form of spot virtual machines (SVMs). In this market, which is often managed through an auction mechanism, users seek optimal bidding strategies for renting SVMs to minimize cost and risk. Uncertainty in the price of SVMs and their low availability/reliability is a challenging issue to bid on the user side. In this paper, we present a robust model for minimizing the cost of executing tasks by considering the uncertainty of the price …

An Xai Approach For Covid-19 Detection Using Transfer Learning With X-Ray Images, Salih Sarp, Ferhat Ozgur Catak, Murat Kuzlu, Umit Cali, Huseyin Kusetogullari, Yanxiao Zhao, Gungor Ates, Ozgur Guler

Engineering Technology Faculty Publications

The coronavirus disease (COVID-19) has continued to cause severe challenges during this unprecedented time, affecting every part of daily life in terms of health, economics, and social development. There is an increasing demand for chest X-ray (CXR) scans, as pneumonia is the primary and vital complication of COVID-19. CXR is widely used as a screening tool for lung-related diseases due to its simple and relatively inexpensive application. However, these scans require expert radiologists to interpret the results for clinical decisions, i.e., diagnosis, treatment, and prognosis. The digitalization of various sectors, including healthcare, has accelerated during the pandemic, with the use …

Wifi Sensing At The Edge Towards Scalable On-Device Wireless Sensing Systems, Steven M. Hernandez

Theses and Dissertations

WiFi sensing offers a powerful method for tracking physical activities using the radio-frequency signals already found throughout our homes and offices. This novel sensing modality offers continuous and non-intrusive activity tracking since sensing can be performed (i) without requiring wearable sensors, (ii) outside the line-of-sight, and even (iii) through the wall. Furthermore, WiFi has become a ubiquitous technology in our computers, our smartphones, and even in low-cost Internet of Things devices. In this work, we consider how the ubiquity of these low-cost WiFi devices offer an unparalleled opportunity for improving the scalability of wireless sensing systems. Thus far, WiFi sensing …

Synthesis And Application Of Redox-Active Covalent Organic Frameworks In Rechargeable Batteries, Mohammad K. Shehab

Theses and Dissertations

Synthesis and Application of Redox-Active Covalent Organic Frameworks in Rechargeable Batteries

Mohammad K. Shehab

Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States

Abstract

In recent years, lithium-ion batteries (LIBs) have been considered the dominant energy storage devices for portable electronics and electric vehicles due to their high energy density, low self-discharge rate, and long cycle life. In LIBs, the traditional positive electrodes employed are mainly derived from metal-containing inorganic compounds composed of cobalt, iron, nickel, or manganese (LiCoO₂, LiMn₂O₄, and LiFePO₄) coupled with graphite as the negative electrode. Despite …

Real-Time Motion Controller For Human-Robot Teams Utilizing Artificial Potential Fields, Gabriella Graziani

Theses and Dissertations

This thesis presents a real-time robotic motion control system for human-robot teams. The framework utilizes artificial potential fields (APFs) to guide robotic agents towards a “goal” agent while navigating around “obstacle” agents; these goals and obstacles are also dynamic agents with their own set of tasks. This system is also developed for a live-programming environment, where a controlling agent updates the tasks of all agents within the system at any time during the system’s runtime. This motion controller was created and tested for a human-robot choreographic team. After the controller was fully integrated on a Trossen Robotic LoCobot Wx200 robotic …

Experimental Evaluation Of Micro-Epidermal Actuators On Flexible Substrates, Courtney D. Bradley

Graduate Research Theses & Dissertations

Does embedding actuators in a flexible substrate increase their performance in hearing aids? What are the differences in damping experienced by actuators of different diameters and at different locations? At what frequency is peak acceleration achieved and what role does the size of the actuator and embedding it in a flexible substrate play? These questions will form the basis of this thesis. This work was done to develop a small non-invasive Band-Aid-©-like hearing aid. The novelty of this device requires a detailed analysis of piezoelectric actuators. This is a continuation of past students’ work on the topic. The main parameters …

Coulomb Blockade-Mediated Field Emission Sources Using Ultra-Nanocrystalline Diamond, Jevin Jensen

Graduate Research Theses & Dissertations

Coulomb Blockade effects in field emission provide interesting means of achieving brighter electron sources for numerous applications, ranging from vacuum electronics to the next generation of electron beam technology. Microelectronics cleanroom methods are presented in this thesis for production of field emission sources moderated by the Coulomb Blockade. The use of common processes is an essential step toward widespread experimentation with Coulomb Blockade-mediated field emission apparatuses. The main feature to be explored is the use of nano-diamond films for their potential applicability for this desired outcome. Ultra-Nanocrystalline Diamond is used in two different ways to achieve this, both as a …

Prioritized Object Detection Integrating Fuzzy Logic Risk Assessment And Planned Path., Khatereh Mohammadi

Graduate Research Theses & Dissertations

Nowadays, Autonomous Vehicles are in the spotlight as a response to the challenges stemming from population growth, worsening traffic congestion, and rising road accidents. Researchers and companies are concentrating on developing Automated Driving Systems (ADS) to tackle these issues.Of the various components that constitute an autonomous vehicle, perception plays a pivotal role, akin to the function of human eyes and the human brain. Therefore, ensuring precise and reliable perception within Autonomous Vehicles is paramount. This thesis is inspired by the principles of human perception, particularly on the road, and endeavors to replicate this process. Just as a human driver does …

A High-Precision Electron Emission Model: Computational Methods For Nanoscale Structures, Alister J. Tencate

Graduate Research Theses & Dissertations

The high-intensity, high-brightness and precision frontiers for charged particle beams are an increasingly important focus for study. Electron microscopy has demonstrated high quality beams from a single nanotip emitter, and cathodes of structured nanoscale arrays show promise as ultracold electron sources. Optimization of the cathode design for precision applications necessitates a detailed treatment of the interplay between the structure geometry, quantum mechanical emission mechanism, and electromagnetic interactions between the emitted electrons and the boundary interface. This dissertation details the numerical tools developed to simulate these processes efficiently with enough fidelity to be accurate even in the ultracold regime.

Conventional simulation …

Analysis Of Localization Algorithms For Wireless Sensor Networks Using Binary Data, Alexander Joseph Hart

Graduate Research Theses & Dissertations

The detection, localization, and tracking of environmental and physical conditions can be accomplished using wireless sensor networks (WSNs). Recent advancements in sensors, processors, and wireless communications have improved the quality and acquisition speed of data in WSNs. However, the data gathered by a WSN is inherently random due to component and environmental variations. Thus, statistical signal processing algorithms are needed to analyze the random data in a robust way. Though many algorithms for the analysis of random data are established and available, they are problem-specific and must be adapted to the application. This thesis provides an analysis of established localization …

Probing Signal-Based Data-Driven Modeling Of Power Electronics Smart Converter Dynamics Using Power Hardware-In-The-Loop, Nischal Guruwacharya

Electronic Theses and Dissertations

The main objective of this dissertation is to develop a generalized simulation and modeling framework for extracting dynamics of power electronic converters (PECs) with grid support functions (GSFs) and validate model accuracy through experimental comparison with physical measurements. The dynamic models obtained from this modeling framework aim to facilitate accurate dynamic analysis of a highly integrated power system comprising inverter-based resources (IBRs), specifically for stability assessment. These dynamic models helped in reducing simulation time and computational complexity, thereby enhancing efficiency. Moreover, it provides valuable insights for utilities and grid operators involved in effective system planning, operation, and dispatch. The dynamics …

Implications Of Physical Fault Injections On Single Chip Motes, Sara Faour, Mališa Vučinić, Filip Maksimovic, David Burnett, Paul Muhlethaler, Thomas Watteyne, Kristofer Pister

Electrical and Computer Engineering Faculty Publications and Presentations

Single-chip motes are wireless sensor nodes that integrate computation, communication, power and sensing on a single chip. We consider the security threats these novel devices are subject to when employed in safety-critical applications. Fault injection attacks are a prominent form of physical attacks that pose a threat to the normal and secure functioning of targeted devices, potentially compromising their intended behavior. These attacks have been studied mainly on commercial off-the-shelf devices which rely on external components such as crystal oscillators and passives. Such external components are absent from single-chip motes, resulting in a uniquely different attack surface compared to commercial …

Survey Of Routing Techniques-Based Optimization Of Energy Consumption In Sd-Dcn, Mohammed Nsaif, Gergely Kovásznai, Ali Malik, Ruairí De Fréin

Articles

The increasing power consumption of Data Center Networks (DCN) is becoming a major concern for network operators. The object of this paper is to provide a survey of state-of-the-art methods for reducing energy consumption via (1) enhanced scheduling and (2) enhanced aggregation of traffic flows using Software-Defined Networks (SDN), focusing on the advantages and disadvantages of these approaches. We tackle a gap in the literature for a review of SDN-based energy saving techniques and discuss the limitations of multi-controller solutions in terms of constraints on their performance. The main finding of this survey paper is that the two classes of …

Boosting Snr Of Cascaded Fbgs In A Sapphire Fiber Through A Rapid Heat Treatment, Farhan Mumtaz, Hanok Tekle, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex Gerald, Jie Huang

PSMRC Faculty Research

This Letter reports the performance of femtosecond (fs) laser-written distributed fiber Bragg gratings (FBGs) under high-temperature conditions up to 1600°C and explores the impact of rapid heat treatment on signal-to-noise ratio (SNR) enhancement. FBGs are essential for reliable optical sensing in extreme temperature environments. Comprehensive tests demonstrate the remarkable performance and resilience of FBGs at temperatures up to 1600°C, confirming their suitability for deployment in such conditions. The study also reveals significant fringe visibility improvements of up to ∼10 dB on a 1-m-long sapphire optical fiber through rapid heat treatment, representing a first-time achievement to the best of our knowledge. …