Engineering Commons^™

Reputation-Aware Trajectory-Based Data Mining In The Internet Of Things (Iot), Samia Tasnim

FIU Electronic Theses and Dissertations

Internet of Things (IoT) is a critically important technology for the acquisition of spatiotemporally dense data in diverse applications, ranging from environmental monitoring to surveillance systems. Such data helps us improve our transportation systems, monitor our air quality and the spread of diseases, respond to natural disasters, and a bevy of other applications. However, IoT sensor data is error-prone due to a number of reasons: sensors may be deployed in hazardous environments, may deplete their energy resources, have mechanical faults, or maybe become the targets of malicious attacks by adversaries. While previous research has attempted to improve the quality of …

Development Of A System For Assessing And Minimizing Health Risk During Wastewater Conveyance And Treatment Processes, Mariana Pitiriciu

FIU Electronic Theses and Dissertations

Many studies on volatile organic compound (VOC) emissions have focused on treatment plants sewage at various locations throughout the world, but they seldom report VOC emissions derived from sewer networks and sewer transportation systems, as compared to wastewater treatment plants. This study focuses on understanding the occurrence of VOCs produced from sewer networks in municipalities or counties throughout the State of Florida (United States) and identifying potential health risks to sewer workers. Common VOCs were identified in wastewater treatment plant influents using available analytical reports. Gas-phase samples from sewer manholes in the City of Hallandale Beach were collected and analyzed …

Trajectory Privacy Preservation And Lightweight Blockchain Techniques For Mobility-Centric Iot, Abdur Bin Shahid

FIU Electronic Theses and Dissertations

Various research efforts have been undertaken to solve the problem of trajectory privacy preservation in the Internet of Things (IoT) of resource-constrained mobile devices. Most attempts at resolving the problem have focused on the centralized model of IoT, which either impose high delay or fail against a privacy-invading attack with long-term trajectory observation. These proposed solutions also fail to guarantee location privacy for trajectories with both geo-tagged and non-geo-tagged data, since they are designed for geo-tagged trajectories only. While a few blockchain-based techniques have been suggested for preserving trajectory privacy in decentralized model of IoT, they require large storage capacity …

Freeway Performance Measurement In A Connected Vehicle Environment Utilizing Traffic Disturbance Metrics, Leila Azizi

FIU Electronic Theses and Dissertations

The introduction of connected vehicles, connected and automated vehicles, and advanced infrastructure sensors will allow the collection of microscopic measures that can be used in combination with macroscopic measures for better estimation of traffic safety and mobility. This dissertation examines the use of microscopic measures in combination with the usually used macroscopic measures for traffic congestion evaluation, traffic state categorization, traffic flow breakdown prediction, and estimation of traffic safety. The considered macroscopic measures are the mean speed, traffic flow rate, and occupancy. The investigated microscopic measures for the stated purpose are: standard deviations of individual vehicle’s speeds, standard deviation of …

Malware Analysis For Evaluating The Integrity Of Mission Critical Devices, Robert Heras

FIU Electronic Theses and Dissertations

The rapid evolution of technology in our society has brought great advantages, but at the same time it has increased cybersecurity threats. At the forefront of these threats is the proliferation of malware from traditional computing platforms to the rapidly expanding Internet-of-things. Our research focuses on the development of a malware detection system that strives for early detection as a means of mitigating the effects of the malware's execution.

The proposed scheme consists of a dual-stage detector providing malware detection for compromised devices in order to mitigate the devices malicious behavior. Furthermore, the framework analyzes task structure features as well …

Offset Electrodes For Enhanced Neural Recording In Microchannels, Iian Black

FIU Electronic Theses and Dissertations

Microchannel electrodes have emerged in recent years as promising interfaces for recording signals in peripheral nerves. Unlike many technologies, microchannels maintain stable long-term connections and can record activity in individual or small groups of axons. Unfortunately, a traditional symmetrical mid-channel electrode configuration, designed to reduce noise artifacts, prevents microchannels from being used to distinguish between signals traveling in opposite directions. This is a profound limitation given that most nerves contain a mix of efferent and afferent axons and microchannels were initially conceived and later used as the basic building block in arrays designed to record bi-directional neural traffic in regenerated …

The Applications Of Intumescent Technologies In Support Of D&D Activities Across The Doe Complex, Joshua Alan Nunez

FIU Electronic Theses and Dissertations

Nuclear facilities in the process of Deactivation and Decommissioning (D&D) face several enormous challenges. Decommissioning is only part of the final shutdown process of a nuclear facility. The majority of the DOE facilities, like most industries, face fire hazards or extreme heat conditions. This study aims to research, test, and validate the operational performance of commercially available polyurethane expanding intumescent foams as potential fixatives for immobilizing residual contamination while preserving fire resiliency. Due to the novelty of this unique problem set and approach, existing international standards (ASTM/NIST/etc.) were reviewed for best-fit platforms with which to build testing protocols from. Once …

Synergistic Activation Of Inspiratory Muscles By An Adaptive Closed-Loop Controller, Rabeya Zinnat Adury

FIU Electronic Theses and Dissertations

During diaphragmatic pacing reverse recruitment of muscle fibers causes muscle fatigue. Current diaphragmatic pacing paradigms also do not permit sigh-like behavior. In spontaneously breathing anesthetized rats, studies were carried out to determine if synergized pacing of external intercostal muscles and the diaphragm would increase the efficiency of diaphragm stimulation and thus a) achieve the desired ventilatory breath volume profile with reduced diaphragm muscle fatigue, and/or b) be able to elicit sigh-like behavior by periodically increasing stimulation. Under combined inspiratory muscle stimulation, a fatigue index calculated for the diaphragm muscle (n=6 rats) was significantly lower (p<0.05) than in the …

Isolated Single-Stage Power Electronic Building Blocks Using Medium Voltage Series-Stacked Wide-Bandgap Switches, Noureldeen Mohamed Elsayad

FIU Electronic Theses and Dissertations

The demand for efficient power conversion systems that can process the energy at high power and voltage levels is increasing every day. These systems are to be used in microgrid applications. Wide-bandgap semiconductor devices (i.e. Silicon Carbide (SiC) and Gallium Nitride (GaN) devices) are very promising candidates due to their lower conduction and switching losses compared to the state-of-the-art Silicon (Si) devices. The main challenge for these devices is that their breakdown voltages are relatively lower compared to their Si counterpart. In addition, the high frequency operation of the wide-bandgap devices are impeded in many cases by the magnetic core …

Mechanical Behavior Of Ternary Metallic Glasses And Their Composites, Xue Liang

FIU Electronic Theses and Dissertations

The vast demands for advanced materials have been putting tremendous pressure on materials scientists and engineers to discover and produce novel lighter and stiffer materials. This dissertation is devoted to the development and fundamental understanding of the strength and the structures within Aluminum ternary metallic glasses (MGs) and their composites, which have a low density and promising high strength. The dissertation focuses on the following content: The multi-objective optimization algorithm predicted the Al_16.5Ni₈Ce_75.5 ternary metallic glass composition with an improved glass-forming ability (supercooled liquid region ∆����=29K), based on the provided dataset. Inoue Criteria can predict …

Algorithms And Circuits For Analog-Digital Hybrid Multibeam Arrays, Paboda Viduneth A. Beruwawela Pathiranage

FIU Electronic Theses and Dissertations

Fifth generation (5G) and beyond wireless communication systems will rely heavily on larger antenna arrays combined with beamforming to mitigate the high free-space path-loss that prevails in millimeter-wave (mmW) and above frequencies. Sharp beams that can support wide bandwidths are desired both at the transmitter and the receiver to leverage the glut of bandwidth available at these frequency bands. Further, multiple simultaneous sharp beams are imperative for such systems to exploit mmW/sub-THz wireless channels using multiple reflected paths simultaneously. Therefore, multibeam antenna arrays that can support wider bandwidths are a key enabler for 5G and beyond systems.

In general, N- …

Continuous-Time Algorithms And Analog Integrated Circuits For Solving Partial Differential Equations, Nilan Udayanga Galabada Kankanamge

FIU Electronic Theses and Dissertations

Analog computing (AC) was the predominant form of computing up to the end of World War II. The invention of digital computers (DCs) followed by developments in transistors and thereafter integrated circuits (IC), has led to exponential growth in DCs over the last few decades, making ACs a largely forgotten concept. However, as described by the impending slow-down of Moore’s law, the performance of DCs is no longer improving exponentially, as DCs are approaching clock speed, power dissipation, and transistor density limits. This research explores the possibility of employing AC concepts, albeit using modern IC technologies at radio frequency (RF) …

Sensor-Based Adaptive Control And Optimization Of Lower-Limb Prosthesis., Roozbeh Atri

FIU Electronic Theses and Dissertations

Recent developments in prosthetics have enabled the development of powered prosthetic ankles (PPA). The advent of such technologies drastically improved impaired gait by increasing balance and reducing metabolic energy consumption by providing net positive power. However, control challenges limit performance and feasibility of today’s devices. With addition of sensors and motors, PPA systems should continuously make control decisions and adapt the system by manipulating control parameters of the prostheses. There are multiple challenges in optimization and control of PPAs. A prominent challenge is the objective setup of the system and calibration parameters to fit each subject. Another is whether it …

Development Of Local And Global Corrosion Sensing Technique To Monitor Structural Behavior Of Prestressed Concrete Structures, Dewan Z. Hossain

FIU Electronic Theses and Dissertations

Corrosion of steel rebar in reinforced concrete structures is a concern for highway bridge owners. According to 2002 study by the Federal Highway Administration, ~15% of the highway bridges in the US are structurally deficient due to corrosion and have an estimated annual direct cost of $8.3 billion. Generally, in post-tensioned bridges, ducts filled with poor or incomplete grouting can allow the tendons to come into contact with water, leading to corrosion and fracture. Although new and improved procedures of grouting have been developed to reduce the instances of poor grouting, the problem of how to reliably inspect tendons on …

Data Analytics And Machine Learning To Enhance The Operational Visibility And Situation Awareness Of Smart Grid High Penetration Photovoltaic Systems, Aditya Sundararajan

FIU Electronic Theses and Dissertations

Electric utilities have limited operational visibility and situation awareness over grid-tied distributed photovoltaic systems (PV). This will pose a risk to grid stability when the PV penetration into a given feeder exceeds 60% of its peak or minimum daytime load. Third-party service providers offer only real-time monitoring but not accurate insights into system performance and prediction of productions. PV systems also increase the attack surface of distribution networks since they are not under the direct supervision and control of the utility security analysts.

Six key objectives were successfully achieved to enhance PV operational visibility and situation awareness: (1) conceptual cybersecurity …

Edge Iot Driven Framework For Experimental Investigation And Computational Modeling Of Integrated Food, Energy, And Water System, Yemeserach Taye Mekonnen

FIU Electronic Theses and Dissertations

As the global population soars from today’s 7.3 billion to an estimated 10 billion by 2050, the demand for Food, Energy, and Water (FEW) resources is expected to more than double. Such a sharp increase in demand for FEW resources will undoubtedly be one of the biggest global challenges. The management of food, energy, water for smart, sustainable cities involves a multi-scale problem. The interactions of these three dynamic infrastructures require a robust mathematical framework for analysis. Two critical solutions for this challenge are focused on technology innovation on systems that integrate food-energy-water and computational models that can quantify the …

Corrosion Durability Of A Nano-Particle Enriched Zinc-Rich Coating System For Highway Steel Bridges, Saiada Fuadi Fancy

FIU Electronic Theses and Dissertations

Corrosion is a major concern for the long-term durability and structural integrity of steel components of highway bridges when unprotected. The application of protective coatings has been widely used for corrosion mitigation of atmospherically exposed structural steel. At present, the zinc-rich primer (ZRP) based three-coat system is widely used in the United States. The metallic zinc pigment ideally would provide corrosion resistance by sacrificial as well as barrier protection. The life of these coating systems is at best only half of the bridge design life. Furthermore, premature degradation may occur if there are flaws in the system due to improper …

A Privacy Framework For Decentralized Applications Using Blockchains And Zero Knowledge Proofs, David Gabay

FIU Electronic Theses and Dissertations

With the increasing interest in connected vehicles along with electrification opportunities, there is an ongoing effort to automate the charging process of electric vehicles (EVs) through their capabilities to communicate with the infrastructure and each other. However, charging EVs takes time and thus in-advance scheduling is needed. As this process is done frequently due to limited mileage of EVs, it may expose the locations and charging pattern of the EV to the service providers, raising privacy concerns for their users. Nevertheless, the EV still needs to be authenticated to charging providers, which means some information will need to be provided …

Graphene Foam Reinforced Shape Memory Polymer Epoxy Composites, Adeyinka Idowu

FIU Electronic Theses and Dissertations

Shape memory polymer (SMP) epoxy has received growing interest due to its facile processing, low density, and high recoverable strain. Despite these positive attributes, SMP epoxy has drawbacks such as slow recovery rate, and inferior mechanical properties. The slow recovery rate restricts the use of SMP epoxy as a functional structure.

The aim of the present work is to explore the capabilities of three-dimensional (3D) graphene foam (GrF) and graphene nanoplatelet (GNP) as reinforcements in SMP epoxy to overcome their slow recovery and improve the mechanical properties. GrF and GNP based SMP epoxy composites are fabricated by mold-casting approach and …

Machine Learning And Image Processing For Noise Removal And Robust Edge Detection In The Presence Of Mixed Noise, Mehdi Mafi

FIU Electronic Theses and Dissertations

The central goal of this dissertation is to design and model a smoothing filter based on the random single and mixed noise distribution that would attenuate the effect of noise while preserving edge details. Only then could robust, integrated and resilient edge detection methods be deployed to overcome the ubiquitous presence of random noise in images. Random noise effects are modeled as those that could emanate from impulse noise, Gaussian noise and speckle noise.

In the first step, evaluation of methods is performed based on an exhaustive review on the different types of denoising methods which focus on impulse noise, …

Click Fraud Detection In Online And In-App Advertisements: A Learning Based Approach, Thejas Gubbi Sadashiva

FIU Electronic Theses and Dissertations

Click Fraud is the fraudulent act of clicking on pay-per-click advertisements to increase a site’s revenue, to drain revenue from the advertiser, or to inflate the popularity of content on social media platforms. In-app advertisements on mobile platforms are among the most common targets for click fraud, which makes companies hesitant to advertise their products. Fraudulent clicks are supposed to be caught by ad providers as part of their service to advertisers, which is commonly done using machine learning methods. However: (1) there is a lack of research in current literature addressing and evaluating the different techniques of click fraud …

Decoding Geometric Origin Of Geomechanical Properties, Sumana Bhattacharya

FIU Electronic Theses and Dissertations

Granular materials such as soil and aggregate, are ubiquitous in nature and the understanding of their mechanical behavior is of great importance to better predict and design the civil infrastructure. The particle geometry is a key information to robustly establish the link between the underlying grain-scale mechanisms and the macroscopic behavior of granular materials. However, the characteristics of the particle geometry remain to be better understood. For example, we do not know how the volume is related to the surface area for irregularly shaped particles in general. Their relation clearly depends on the morphology, dictating that volume, surface area, and …

Measuring Collagen Arrangement And Its Relationship With Preterm Birth Using Mueller Matrix Polarimetry, Joseph James Chue-Sang

FIU Electronic Theses and Dissertations

Preterm birth (PTB) is defined as delivery prior to 37 weeks of gestation. It is the leading cause of infant death worldwide, responsible for infant neurological disorders, long-term cognitive impairment, as well as chronic health issues involving the auditory, visual, digestive, and respiratory systems. In expectant mothers, causes for PTB can include infection, inflammation, vascular disease, short intervals between pregnancies, multiple gestations and genetic factors. In the U.S., PTB occurs in over 11% of births and at an elevated 18.1% in Miami-Dade County, FL; while in the developing world the incidence of PB is over 15%. Early identification of at-risk …

Lithium-Ion Hybrid Capacitor Devices: Towards High-Performance Electrochemical Capacitive Energy Storage, Ebenezer Dotun Adelowo

FIU Electronic Theses and Dissertations

Hybridization of lithium-ion batteries (LIBs) and electrochemical capacitors (ECs) at electrode level can potentially provide high-performance capacitive energy storage having a good combination of high energy density, high power density, and moderate cycling longevity. Lithium-ion hybrid capacitor (LIHC) system consisting of a battery-type anode and a capacitor-type cathode represents an attractive hybridization approach aimed at bridging the performance gap between the two energy storage systems. The application of such energy storage system may extend the functionalities of many electronic devices.

In this dissertation, different LIHC configurations were designed and evaluated. An LIHC device comprising electrostatically sprayed reduced graphene oxide (rGO)-based …

Adaptive Closed-Loop Neuromorphic Controller For Use In Respiratory Pacing, Ricardo Siu

FIU Electronic Theses and Dissertations

Respiratory pacing can treat ventilatory insufficiency through electrical stimulation of the respiratory muscles, or the respective innervating nerves, to induce ventilation. It avoids some of the adverse effects associated with mechanical ventilation such as risk of diaphragm atrophy and lung damage. However, current respiratory pacing systems provide stimulation in an open-loop manner. This often requires users to undergo frequent tuning sessions with trained clinicians if the specified stimulation parameters are unable to induce sufficient ventilation in the presence of time-varying changes in muscle properties, chest biomechanics, and metabolic demand. Lack of adaptation to these changes may lead to complications arising …

Towards Stable Electrochemical Sensing For Wearable Wound Monitoring, Sohini Roychoudhury

FIU Electronic Theses and Dissertations

Wearable biosensing has the tremendous advantage of providing point-of-care diagnosis and convenient therapy. In this research, methods to stabilize the electrochemical sensing response from detection of target biomolecules, Uric Acid (UA) and Xanthine, closely linked to wound healing, have been investigated. Different kinds of materials have been explored to address such detection from a wearable, healing platform. Electrochemical sensing modalities have been implemented in the detection of purine metabolites, UA and Xanthine, in the physiologically relevant ranges of the respective biomarkers. A correlation can be drawn between the concentrations of these bio-analytes and wound severity, thus offering probable quantitative insights …

Many-Objective Hybrid Optimization Under Uncertainty With Applications, Sohail Reddy

FIU Electronic Theses and Dissertations

A novel method for solving many-objective optimization problems under uncertainty was developed. It is well known that no single optimization algorithm performs best for all problems. Therefore, the developed method, a many-objective hybrid optimizer (MOHO), uses five constitutive algorithms and actively switches between them throughout the optimization process allowing for robust optimization. MOHO monitors the progress made by each of the five algorithms and allows the best performing algorithm more attempts at finding the optimum. This removes the need for user input for selecting algorithm as the best performing algorithm is automatically selected thereby increasing the probability of converging to …

Centralized And Distributed Detection Of Compromised Smart Grid Devices Using Machine Learning And Convolution Techniques, Cengiz Kaygusuz

FIU Electronic Theses and Dissertations

The smart grid concept has further transformed the traditional power grid into a massive cyber-physical system that depends on advanced two-way communication infrastructure. While the introduction of cyber components has improved the grid, it has also broadened the attack surface. In particular, the threat stemming from compromised devices pose a significant danger: An attacker can control the devices to change the behavior of the grid and can impact the measurements or damage the grid equipment. In this thesis, to detect such malicious smart grid devices, we propose a novel machine learning and convolution-based framework, named PowerWatch, that is able to …

Protection Of Active Distribution Networks And Their Cyber Physical Infrastructure, Hany Fawzy Kamel Habib

FIU Electronic Theses and Dissertations

Today’s Smart Grid constitutes several smaller interconnected microgrids. However, the integration of converter-interfaced distributed generation (DG) in microgrids has raised several issues such as the fact that fault currents in these systems in islanded mode are way less than those in grid connected microgrids. Therefore, microgrid protection schemes require a fast, reliable and robust communication system, with backup, to automatically adjust relay settings for the appropriate current levels according to the microgrid’s operation mode. However, risks of communication link failures, cyber security threats and the high cost involved to avoid them are major challenges for the implementation of an economic …

Ultra-Wideband Phased Arrays For Small Mobile Platforms, Alexander D. Johnson

FIU Electronic Theses and Dissertations

This dissertation presents the development of a new class of Ultra-Wideband (UWB) apertures for aerial applications by introducing designs with over 50:1 bandwidth and novel differential feeding approaches. Designs that enable vertical integration for flip-chip millimeter-wave (UWB) transceivers are presented for small aerial platforms. Specifically, a new scalable tightly coupled array is introduced with differential feeding for chip integration. This new class of beam-forming arrays are fabricated and experimentally tested for validation with operation from as low as 130 MHz up to 18 GHz. A major achievement is the study of millimeter wave beamforming designs that operate from 22-80 GHz, …