Engineering Commons^™

Review—Machine Learning Techniques In Wireless Sensor Network Based Precision Agriculture, Yemeserach Mekonnen, Srikanth Namuduri, Lamar Burton, Arif I. Sarwat, Shekhar Bhansali

Electrical and Computer Engineering Faculty Publications

The use of sensors and the Internet of Things (IoT) is key to moving the world's agriculture to a more productive and sustainable path. Recent advancements in IoT, Wireless Sensor Networks (WSN), and Information and Communication Technology (ICT) have the potential to address some of the environmental, economic, and technical challenges as well as opportunities in this sector. As the number of interconnected devices continues to grow, this generates more big data with multiple modalities and spatial and temporal variations. Intelligent processing and analysis of this big data are necessary to developing a higher level of knowledge base and insights …

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 …

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 …

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 …

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 …

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, …

A Novel Audiovisual P300-Speller Paradigm Based On Cross-Modal Spatial And Semantic Congruence, Zhaohua Lu, Changchun University Of Science And Technology, Ning Gao, Jingjing Yang, Ou Bai

Electrical and Computer Engineering Faculty Publications

Objective: Although many studies have attempted to improve the performance of the visual-based P300-speller system, its performance is still not satisfactory. The current system has limitations for patients with neurodegenerative diseases, in which muscular control of the eyes may be impaired or deteriorate over time. Some studies have shown that the audiovisual stimuli with spatial and semantic congruence elicited larger event-related potential (ERP) amplitudes than do unimodal visual stimuli. Therefore, this study proposed a novel multisensory P300-speller based on audiovisual spatial and semantic congruence.

Methods: We designed a novel audiovisual P300-speller paradigm (AV spelling paradigm) in which the pronunciation and …

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 …

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 …

A Hardware-Assisted Insider Threat Detection And Prevention Framework, Kyle W. Denney

FIU Electronic Theses and Dissertations

Today, the USB protocol is among the most widely used protocols. However, the mass-proliferation of USB has led to a threat vector wherein USB devices are assumed innocent, leaving computers open to an attack. Malicious USB devices can disguise themselves as benign devices to insert malicious commands to connected end devices. A rogue device appears benign to the average OS, requiring advanced detection schemes to identify malicious devices. However, using system-level hooks, advanced threats may subvert OS-reliant detection schemes. This thesis showcases USB-Watch, a hardware-based USB threat detection framework. The hardware can collect live USB traffic before the data can …

Ultra-Wideband Secure Communications And Direct Rf Sampling Transceivers, Dimitrios Siafarikas

FIU Electronic Theses and Dissertations

Larger wireless device bandwidth results in new capabilities in terms of higher data rates and security. The 5G evolution is focus on exploiting larger bandwidths for higher though-puts. Interference and co-existence issues can also be addressed by the larger bandwidth in the 5G and 6G evolution. This dissertation introduces of a novel Ultra-wideband (UWB) Code Division Multiple Access (CDMA) technique to exploit the largest bandwidth available in the upcoming wireless connectivity scenarios. The dissertation addresses interference immunity, secure communication at the physical layer and longer distance communication due to increased receiver sensitivity. The dissertation presents the design, workflow, simulations, hardware …

Mitigating Colluding Attacks In Online Social Networks And Crowdsourcing Platforms, Georges Arsene K. Kamhoua

FIU Electronic Theses and Dissertations

Online Social Networks (OSNs) have created new ways for people to communicate, and for companies to engage their customers -- with these new avenues for communication come new vulnerabilities that can be exploited by attackers. This dissertation aims to investigate two attack models: Identity Clone Attacks (ICA) and Reconnaissance Attacks (RA). During an ICA, attackers impersonate users in a network and attempt to infiltrate social circles and extract confidential information. In an RA, attackers gather information on a target's resources, employees, and relationships with other entities over public venues such as OSNs and company websites. This was made easier for …

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, …

Unmanned Aerial Vehicles (Uavs) For Integrated Access And Backhaul (Iab) Communications In Wireless Cellular Networks, Abdurrahman Fouda

FIU Electronic Theses and Dissertations

An integrated access and backhaul (IAB) network architecture can enable flexible and fast deployment of next-generation cellular networks. However, mutual interference between access and backhaul links, small inter-site distance and spatial dynamics of user distribution pose major challenges in the practical deployment of IAB networks. To tackle these problems, we leverage the flying capabilities of unmanned aerial vehicles (UAVs) as hovering IAB-nodes and propose an interference management algorithm to maximize the overall sum rate of the IAB network. In particular, we jointly optimize the user and base station associations, the downlink power allocations for access and backhaul transmissions, and the …

Non-Intrusive Affective Assessment In The Circumplex Model From Pupil Diameter And Facial Expression Monitoring, Sudarat Tangnimitchok

FIU Electronic Theses and Dissertations

Automatic methods for affective assessment seek to enable computer systems to recognize the affective state of their users. This dissertation proposes a system that uses non-intrusive measurements of the user’s pupil diameter and facial expression to characterize his /her affective state in the Circumplex Model of Affect. This affective characterization is achieved by estimating the affective arousal and valence of the user’s affective state.

In the proposed system the pupil diameter signal is obtained from a desktop eye gaze tracker, while the face expression components, called Facial Animation Parameters (FAPs) are obtained from a Microsoft Kinect module, which also captures …

Nanocomposite Bienzymatic Sensor For Monitoring Xanthine In Wound Diagnostics, Sohini Roychoudhury, Yogeswaran Umasankar, Pulak Bhushan, Penelope A. Hirt, Flor E. Macquhae, Luis J. Borda, Hadar A. Lev-Tov, Robert Kirsner, Shekhar Bhansali

Electrical and Computer Engineering Faculty Publications

This work reports a biosensor for monitoring xanthine for potential wound healing assessment. Active substrate of the biosensor has xanthine oxidase (XO) and horseradish peroxidase (HRP) physisorbed on a nanocomposite of multiwalled carbon nanotubes (MWCNT) decorated with gold nanoparticles (AuNP). The presence of HRP provided a two-fold increase in response to xanthine, and a three-fold increase in response to the nanocomposite. With a sensitivity of 155.71 nA μM−1 cm−2 the biosensor offers a detection limit of 1.3 μM, with linear response between 22 μM and 0.4 mM. Clinical sample analyses showed the feasibility of xanthine detection from biofluids in a …

Case Study On The Effects Of Partial Solar Eclipse On Distributed Pv Systems And Management Areas, Aditya Sundararajan, Temitayo O. Olowu, Longfei Wei, Shahinur Rahman, Arif I. Sarwat

Electrical and Computer Engineering Faculty Publications

Photovoltaic (PV) systems are weather-dependent. A solar eclipse causes significant changes in these parameters, thereby impacting PV generation profile, performance, and power quality of larger grid, where they connect to. This study presents a case study to evaluate the impacts of the solar eclipse of 21 August 2017, on two real-world grid-tied PV systems (1.4 MW and 355 kW) in Miami and Daytona, Florida, the feeders they are connected to, and the management areas they belong to. Four types of analyses are conducted to obtain a comprehensive picture of the impacts using 1 min PV generation data, hourly weather data, …

Hydrothermal Growth Of Zinc Oxide (Zno) Nanorods (Nrs) On Screen Printed Ides For Ph Measurement Application, Aksaya Kumar A., Naveen Kumar S.K.,, Almaw Ayele Aniley, Renny Edwin Fernandez, Shekhar Bhansali

Electrical and Computer Engineering Faculty Publications

There is considerable interest in nanostructured materials with interdigitated electrodes (IDEs) platforms to detect and monitor the level of various ions in numerous applications. Herein, we report the design and fabrication of IDEs based pH sensor by using hydrothermal growth of ZnO nanorods (NRs). A four-step deposition of ZnO seed layer followed by a hydrothermal treatment lead to the heavily ordered ZnO NRs patterns on the screen printed IDEs. The structural, chemical compositional and electrical properties of the NRs were investigated and examined by using field emission scanning electron microscopy (FeSEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray …

Hydrothermal Growth Of Zinc Oxide (Zno) Nanorods (Nrs) On Screen Printed Ides For Ph Measurement Application, Akshaya Kumar A., Naveen Kumar S.K., Almaw Ayele Aniley, Renny Edwin Fernandez, Shekhar Bhansali

Electrical and Computer Engineering Faculty Publications

There is considerable interest in nanostructured materials with interdigitated electrodes (IDEs) platforms to detect and monitor the level of various ions in numerous applications. Herein, we report the design and fabrication of IDEs based pH sensor by using hydrothermal growth of ZnO nanorods (NRs). A four-step deposition of ZnO seed layer followed by a hydrothermal treatment lead to the heavily ordered ZnO NRs patterns on the screen printed IDEs. The structural, chemical compositional and electrical properties of the NRs were investigated and examined by using field emission scanning electron microscopy (FeSEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray …

Single And Multiobjective Optimal Reactive Power Dispatch Based On Hybrid Artificial Physics–Particle Swarm Optimization, Tawfiq M. Aljohani, Ahmed F. Ebrahim, Osama A. Mohammed

Electrical and Computer Engineering Faculty Publications

The optimal reactive power dispatch (ORPD) problem represents a noncontinuous, nonlinear, highly constrained optimization problem that has recently attracted wide research investigation. This paper presents a new hybridization technique for solving the ORPD problem based on the integration of particle swarm optimization (PSO) with artificial physics optimization (APO). This hybridized algorithm is tested and verified on the IEEE 30, IEEE 57, and IEEE 118 bus test systems to solve both single and multiobjective ORPD problems, considering three main aspects. These aspects include active power loss minimization, voltage deviation minimization, and voltage stability improvement. The results prove that the algorithm is …

Control And Optimization Of Energy Storage In Ac And Dc Power Grids, Samy Mohamed

FIU Electronic Theses and Dissertations

Energy storage attracts attention nowadays due to the critical role it will play in the power generation and transportation sectors. Electric vehicles, as moving energy storage, are going to play a key role in the terrestrial transportation sector and help reduce greenhouse emissions. Bulk hybrid energy storage will play another critical role for feeding the new types of pulsed loads on ship power systems. However, to ensure the successful adoption of energy storage, there is a need to control and optimize the charging/discharging process, taking into consideration the customer preferences and the technical aspects. In this dissertation, novel control and …

Nanoparticle-Based Spintronic Computer Logic Switch, Kevin Luongo

FIU Electronic Theses and Dissertations

Spintronics is a rapidly growing research field due to scalability, integrablility within existing VLSI architecture, significantly reduced switching energy and latency while maintaining stable bit orientation (Spin-up, Spin-down). For the first time sub-5nm Spin Transfer Torque –Magnetic Tunneling Junctions (STT-MTJ) were investigated utilizing various Integrated Circuit (IC) fabrication techniques to evaluate novel concepts in logic switches.

Tunneling Magnetoresistance (TMR) was measured in STT-MTJ stacks of Ta/CoFeB/MgO/CoFeB/Ta with differing diameter ferrimagnetic CoFe2O4 nanoparticles (10nm, 4nm and 2nm) embedded in the MgO layer. MR was detected in the 2nm and 4nm particle devices and demonstrated evidence of single electron transport.

Tri-layer STT-MTJ …

Cloud Workload Allocation Approaches For Quality Of Service Guarantee And Cybersecurity Risk Management, Soamar Homsi

FIU Electronic Theses and Dissertations

It has become a dominant trend in industry to adopt cloud computing --thanks to its unique advantages in flexibility, scalability, elasticity and cost efficiency -- for providing online cloud services over the Internet using large-scale data centers. In the meantime, the relentless increase in demand for affordable and high-quality cloud-based services, for individuals and businesses, has led to tremendously high power consumption and operating expense and thus has posed pressing challenges on cloud service providers in finding efficient resource allocation policies.

Allowing several services or Virtual Machines (VMs) to commonly share the cloud's infrastructure enables cloud providers to optimize resource …

Study Of Charge Carrier Transport In Graphene And Graphite As Two Dimensional And Quasi-Two Dimensional Materials And Their Interfaces, Nalat Sornkhampan

FIU Electronic Theses and Dissertations

Evidence of superconductivity in phosphorous-doped graphite and graphene has been observed at temperatures in the vicinity of 260 K. This evidence includes transport current, magnetic susceptibility, Hall and Nernst measurements. All of these measurements indicate a transition of a type II superconductor without a phase of type I until below the limits of the measurement capabilities.

Vortex states are inferred from periodically repeated steps in the R vs. T characteristics of Highly Oriented Pyrolytic Graphite and exfoliated doped multilayer graphene. The presence of vortices has been confirmed with thermal gradient driven Nernst measurements. Magnetic susceptibility measurements have shown results qualitatively …

Mesoscale Ceramic Cylindrical Ion Trap Mass Analyzers For In Situ Sample Analysis, Patrick Roman

FIU Electronic Theses and Dissertations

As wireless network devices and IOT connectivity develop, the application and demand for small, low power, in situ sensors and instruments will expand. There are continuous efforts in the miniaturization of sensors and scientific instrument systems for conventional to field deployable and rugged hand held units for personal use to extreme harsh environment applications. This work investigates mesoscale cylindrical ion trap (CIT) mass analyzer design and the benefits of CITs realized via additive manufactured metalized ceramic material systems for improved ion signal, low power performance, and extended dynamic range. Rugged monolithic miniature mass spectrometer ceramic CIT chips have been produced …