Engineering Commons^™

Phasor Domain Modeling Of Type-Iii Wind Turbines, Mohammed Alqahtani

USF Tampa Graduate Theses and Dissertations

This dissertation research focuses on developing an accurate steady-state phasor model for Doubly Fed Induction Generator (DFIG)-based wind turbines (Type-III WTs). Unlike the classical synchronous or asynchronous generators, Type-III WTs are electronically coupled to the power grid. The steady-state and dynamic responses of the DFIG-based WTs depend on the behavior of the converters controllers. Accurate modeling requires reproducing the behavior of the power electronics and the control system for various operating scenarios. The analysis of this research area is carried out in two stages or tasks. The first task focuses on the balanced stator voltage situation, while the unbalanced stator …

Adaptive Network Slicing In Fog Ran For Iot With Heterogeneous Latency And Computing Requirements: A Deep Reinforcement Learning Approach, Almuthanna Nassar

USF Tampa Graduate Theses and Dissertations

In view of the recent advances in Internet of Things (IoT) devices and the emerging new breed of smart city applications and intelligent vehicular systems driven by artificial intelligence, fog radio access network (F-RAN) has been recently introduced for the next generation wireless communications. The capability of F-RAN has emerged to overcome the latency limitations of cloud-RAN (C-RAN) and assure the quality-of-service (QoS) requirements of the ultra-reliable-low-latency-communication (URLLC) for IoT applications. To this end, fog nodes (FNs) are equipped with computing, signal processing and storage capabilities to extend the inherent operations and services of the cloud to the edge. However, …

Packaging Of Active Rf Beamforming Ic Utilizing Additive Manufacturing, Ryan Murphy

USF Tampa Graduate Theses and Dissertations

Packaging of an RF Beamforming IC was performed using an additive manufacturingplatform with FDM, microdispensing, laser subtractive manufacturing, and milling. The beamforming IC was embedded within a multilayer device structure in order to feed a 2x2 antenna sub-array in a compact and completely integrated package. Additive manufacturing allows for simple variation in material parameters and properties that enhances the ability to develop integrated system packaging. This study builds on previous investigations and demonstrates the ability to embed an active RF device with measurable gain within a printed plastic substrate. Critical to developing a repeatable method for this packaging solution, initial …

Theory And Application Of Dielectric Rod Antennas And Arrays, Gabriel Saffold

USF Tampa Graduate Theses and Dissertations

Dielectric rods have been used for many years as waveguides and radiators. Their low loss as a transmission line and tendency to radiate at discontinuities have proven useful in applications ranging from fiber optic cables to naval fire control radar. Although this technology is well es- tablished, advances in additive manufacturing techniques and associated materials combined with the ubiquity of wireless communications and their shift to higher frequencies have generated re- newed interest in dielectric rods. Dielectric rod antennas have moderate gain and less conductive loss at higher frequencies. Similar to other surface wave antennas, they can achieve broadband performance.This …

On The Application Of Recursive Nonlinear State Transformations And Nonlinear Feedback To Enable Continuous Thrust Spacecraft Orbital Rendezvous, Parisa Khosravi

USF Tampa Graduate Theses and Dissertations

This dissertation presents a method to address exact feedback linearization problems based on the recursive application of approximate feedback linearization techniques. An approximate feedback linearization method is applied recursively to systems which are known to be an exact feedback linearizable to obtain a family of exact solutions up to the ρ-th degree utilizing the null space that appears as part of the computations. The coordinate transformation and feedback parameters are computed symbolically using a one-step approach in multi-stage form. This algorithm is algebraic and computationally simpler than solving the set of nonlinear partial differential equations. We employ the approximate feedback …

Investigation Of Coo Ato For Solar Cells And Infrared Sheaths, Manopriya Devisetty Subramanyam

USF Tampa Graduate Theses and Dissertations

Solar as an energy source is expected to grow fastest from now to 2050. Increasing the efficiency is usually achieved by increasing the short circuit current density (JSC) and/or the fill factor. Improving the efficiency of solar cells will be an ongoing effort.Structurally solar technologies can be classified into two types, wafer-based and thin-film-based. Wafer solar cells have been used in this study. The anti-reflective layer on top of solar cells has been fabricated by a process called electrospinning to tune the solar cells' top surface with the desired thickness and dimensions of the nanofibers. The nanofibers' dimensions, shape, and …

Analysis Of Denial Of Service Attacks In Emerging Software Defined Network Infrastructures, Andrea P. Wright

USF Tampa Graduate Theses and Dissertations

Software defined networking (SDN) improves upon traditional networking protocol technologies by decoupling the data and control planes and moving all control provisioning decisions to a centralized SDN controller entity. This concept has matured over the last decade, having gained strong industry traction, and is now being widely deployed within enterprise and carrier networks to streamline network services provisioning and reduce costs. Overall, centralized control delivers much more cost-effective and flexible networking setups that can support a wide range of customized user-driven network management applications, e.g., traffic engineering, security, survivability, admission control, policy control, etc.

However, the separation of the data …

Power System Optimization Methods: Convex Relaxation And Benders Decomposition, Minyue Ma

USF Tampa Graduate Theses and Dissertations

Power system optimization methods are wildly used to solve power system problems. Engineers adopt different methods to keep the reliability and efficiency of the power system operation, planning and control. This dissertation focuses on the application and implementation of two optimization methods: Convex relaxation and Benders' decomposition.

The first part of the dissertation focuses on the application of convex relaxation to solve Alternating Current Optimal Power Flow (ACOPF) problems. In the completed work, a 3-node cycle based sparse convex relaxation is proposed to solve ACOPF problems. This method adds virtual lines in minimal chordless cycles to decompose each of them …

Effect Of Se Composition In Cdse1-XTEx/Cdte Solar Cells, Sheikh Tawsif Elahi

USF Tampa Graduate Theses and Dissertations

Cadmium Telluride solar cell is a leading thin film photovoltaic in the market today. Constant enhancement of efficiency in the last decade has made its position firmer in research interest as well. The record cell efficiency for CdTe solar cells is 22.1%. The theoretical limit suggests that there is still room for efficiency improvements. Reducing the band gap of CdTe solar cells can improve the short circuit current and overall cell performance.

This work focuses on bandgap engineering of the CdTe layer by incorporating Selenium (Se) in to form the compound CdS_exTe_1-x (CST) which can have a …

Thermal Management Of Lithium-Ion Batteries Using Supercapacitors, Sanskruta Dhotre

USF Tampa Graduate Theses and Dissertations

As the market for renewable resources increases, the bandwidth of applications using Li-ion batteries as the primary source of energy also increases. Li-ion batteries are at a risk of undergoing thermal runaway under uncontrolled situations. Overcharging, over-discharging, high internal temperatures, etc. are all factors towards the gradual degradation of Li-ion battery performance. Therefore, it is important to have an efficient battery management system to ensure the smooth functioning of the battery.

Thermal management systems is an important aspect of the battery management system to keep battery temperatures under critical levels. Although, there are various methods of cooling down the battery …

Strategies In Botnet Detection And Privacy Preserving Machine Learning, Di Zhuang

USF Tampa Graduate Theses and Dissertations

Peer-to-peer (P2P) botnets have become one of the major threats in network security for serving as the infrastructure that responsible for various of cyber-crimes. Though a few existing work claimed to detect traditional botnets effectively, the problem of detecting P2P botnets involves more challenges. In this dissertation, we present two P2P botnet detection systems, PeerHunter and Enhanced PeerHunter. PeerHunter starts from a P2P hosts detection component. Then, it uses mutual contacts as the main feature to cluster bots into communities. Finally, it uses community behavior analysis to detect potential botnet communities and further identify bot candidates. Enhanced PeerHunter is an …

Piezoelectrically-Transduced Zno-On-Diamond Resonators With Enhanced Signal-To-Noise Ratio And Power-Handling Capability For Sensing And Wireless Communication Applications, Xu Han

USF Tampa Graduate Theses and Dissertations

Microelectromechanical system (MEMS) resonators emerged a few decades ago, and now they have been well developed and commercially utilized as a core part in many radio frequency (RF) communication hardware as well as micro-sensing and detections for many different latest applications. Since MEMS-based devices are made small thanks to the microfabrication technology's improvement, the cost can be drastically reduced when mass-produced on wafer batches, and the devices still maintain a decent performance with negligible power consumption. This perfectly fits into the requirements of the newest internet-of-thing (IoT) and headset applications. Our previous research mainly focuses on designing and fabricating MEMS …

Multilayered Transmission Lines, Antennas And Phased Arrays With Structurally Integrated Control Electronics Using Additive Manufacturing, Merve Kacar

USF Tampa Graduate Theses and Dissertations

This dissertation presents high-performance transmission lines, antennas, and phased arrays with novel packaging techniques by harnessing design flexibilities of additive manufacturing (AM). AM enables realizing multilayered RF electronics with complex geometrical structures that are not practical using conventional fabrication methods. Design flexibilities offered by AM as customized dielectric shapes/thicknesses, dielectric properties, metallization on conformal surfaces, and structural packaging are harnessed for multilayered RF applications. Although several works demonstrated the viability of AM for antenna realizations, its capability for addressing the needs of wideband, high radiation efficiency antenna systems packaged with active RF circuit components remains relatively unexplored. The first major …

Reading And Programming Spintronic Devices For Biomimetic Applications And Fault-Tolerant Memory Design, Kawsher Ahmed Roxy

USF Tampa Graduate Theses and Dissertations

Despite the triumph of conventional computing architectures till today, there emerges a lotof computing problems that are solved poorly by them. The reason behind this are twofold: i) the computing algorithm is incompetent in solving those problems, and ii) non-ideal effects of the traditional device technologies outperform the benets of using them. Hence, extensive research eorts have been put to devise novel algorithms as well as new devices. Among them spintronic devices demonstrate better performance in traditional architectures as well as offers way better solution to a lot of new problems when bundled with unconventional computing algorithms. Apart from being …

Cost Efficient Algorithms And Methods For Spectral Efficiency In Future Radio Access, Murat Karabacak

USF Tampa Graduate Theses and Dissertations

The growing interest in data-hungry wireless applications of mobile devices has led the cellular industry to look for new frequencies and new techniques for utilization of next-generation wireless technologies. As millimeter-wave (mmWave) communication becoming a promising solution, It can provide greater bandwidth and higher data rates in future radio access. While in the hostile environment of mmWave bands, the signals suffer from high propagation loss, the smaller wavelengths of mmWave frequencies make it possible to practically pack a large number of antennas with reasonable form factors. Thus, mmWave communication can provide directional transmission with high gain antenna arrays to penetrate …

Design And Implementation Of Solid/Solid Phononic Crystal Structures In Lateral Extensional Thin-Film Piezoelectric On Silicon Micromechanical Resonators, Abdulrahman Alsolami

USF Tampa Graduate Theses and Dissertations

Achieving high quality factor in MEMS resonator devices is a critical demand for today’s wireless communication and sensing technologies. In order to reach this goal, several dedicated prior works have been conducted based on published literature at different frequency ranges. Particularly, piezoelectrically transduced resonators, which are widely deployed in commercial wireless communication systems, could benefit from greatly improved qualify factor. So far, their development has evolved from thin film bulk acoustic resonators (FBAR’s) using surface attached piezoelectric thin-film transducers with moderate Q factors to high Q resonators equipped with a side-supporting tether (anchor) attached vibrating resonators that allow the devices …

Hybrid Rf Acoustic Resonators And Arrays With Integrated Capacitive And Piezoelectric Transducers, Adnan Zaman

USF Tampa Graduate Theses and Dissertations

Over the past few decades, the usage of mobile communication devices such as smartphones, laptop computers, tablets has grown significantly. Clearly, smartphones and other mobile gadgets have been leading the current and emerging market thanks to the fast growing of wireless communications. Therefore, the wireless communications market is constantly looking for new ways to miniaturize the RF front-ends, while reducing the size, cost, and power consumption. Radio frequency microelectromechanical systems (RF MEMS) is widely viewed as a potential enabling technology for the multi-standard monolithic transceivers on a single chip with high reliability, high performance, and very low DC power consumption. …

Spatial Stereo Sound Source Localization Optimization And Cnn Based Source Feature Recognition, Cong Xu

USF Tampa Graduate Theses and Dissertations

In the process of propagating as a carrier of information in space, in addition to transmitting the information itself, the acoustic signal also contains the position information of the sound source itself and its related physical characteristics. Acoustic signal uses the medium (such as air, water, steel, etc.) in the space to transmit mechanical vibration and longitudinal waves from the sound source to the outside world. The traditional single audio collection device cannot collect position information and sound source characteristic information. Therefore, the signals processed in the audio signal processing process are all mixed source acoustic signals after spatial reverberation. …

Architecture Design And Optimization Of Edge-Enabled Smart Grids, Adetola B. Adeniran

USF Tampa Graduate Theses and Dissertations

The emergence of modern monitoring, communication, computation, and controlequipment into power systems has made them evolve into smart grids that can be thought of as the electric grid of things. This evolution has enhanced the efficiency of the power systems through the availability of a large volume of system data that can help with system functions, nevertheless, it has intensified the communication and computation burden on these systems. While many of such computations were traditionally deployed in central servers, new technologies such as edge computing can provide unique opportunities to address some of the computational challenges and improve the responsiveness …

Analysis Of Computational Modeling Methods As Applied To Single-Crystal Organohalide Perovskites, Jon M. Bebeau

USF Tampa Graduate Theses and Dissertations

Perovskite, specifically MAPbI3, has exploded onto the electronic material forefront, with applications from photovoltaic to optical sensors. Still, there remain many unanswered questions about the electronic, structural and mechanical processes and properties of this perovskite. Computational software exists to model the electronic structure and material properties, to the nano scale, using density-functional theory. The goal of these models it to parallel the physical science of the substance in a computer simulation based on emerging mathematical models of the quantum mechanical behavior. In this study I review the historical use of perovskites in electronics, review the evolution of DFT algorithm developments …

Next-Generation Self-Organizing Communications Networks: Synergistic Application Of Machine Learning And User-Centric Technologies, Chetana V. Murudkar

USF Tampa Graduate Theses and Dissertations

The telecommunications industry is going through a metamorphic journey where the 5G and 6G technologies will be deeply rooted in the society forever altering how people access and use information. In support of this transformation, this dissertation proposes a fundamental paradigm shift in the design, performance assessment, and optimization of wireless communications networks developing the next-generation self-organizing communications networks with the synergistic application of machine learning and user-centric technologies.

This dissertation gives an overview of the concept of self-organizing networks (SONs), provides insight into the “hot” technology of machine learning (ML), and offers an intuitive understanding of the user-centric (UC) …

Implementation Of Sr Flip-Flop Based Puf On Fpga For Hardware Security, Sai Praneeth Sagi

USF Tampa Graduate Theses and Dissertations

Physical Unclonable Functions (PUF) are used for authentication and key generation to obtain a unique signature and are widely used in hardware security applications. In this work, we propose Set-Reset Flip-flop (SRFF) based PUF for FPGAs. We exploit the race around condition of the SRFF to obtain a one-bit signature output which is a function of feedback path delays. In deep sub-micron technology node, delay variations on an FPGA device are significant due to manufacturing process variations. Thus, an SRFF output value is a function of its location on the FPGA device. We implement registers of various bit widths and …

Electrospun Nanofibrous Membrane Based Glucose Sensor With Integration Of Potentiostat Circuit, Kavyashree Puttananjegowda

USF Tampa Graduate Theses and Dissertations

Although wearable and portable biomedical devices are the pillar of modern and smart societies, a large portion the device infrastructure is still under development, operates with poor monitoring and automation, and lacks sufficient communication among components. Moreover, demand for wearable bio-medical devices is expected to increase in the coming years. This situation presents a unique opportunity for electrical engineers to design novel strategies that allow point-of-care diagnostics to satisfy the increasing demand of wearable bio-medical devices. For example, in the medical field there is a rising diabetic population base, high demand for miniature and low-power diagnostic devices, and the need …

Theory, Fabrication, And Characterization Of Perovskite Phototransistor, Fatemeh Khorramshahi

USF Tampa Graduate Theses and Dissertations

In recent years, there has been a significant interest in making electronic devices with low-cost techniques and materials for both industrial and medical applications. Methylammonium lead iodide perovskite (MAPbI3) is one of the novel materials which has drawn much attention owing to its outstanding optical and electrical properties along with inexpensive, simple, and easy fabrication methods. In this work, the feasibility of using microfluidic device fabrication techniques on making a perovskite phototransistor has been studied. The fabrication method well addresses challenges such as lead toxicity and instability.

In the first step, mechanical micromachining and laser engraving were employed to make …

Comprehensive Optimization Models For Voltage Regulation In Pv-Rich Multi-Phase Distribution Systems, Ibrahim Alsaleh

USF Tampa Graduate Theses and Dissertations

The distribution systems are increasingly challenged by the continued prevalence of distributed energy resources (DERs), signaling the need for new computational tools to systemize their involvement, coordinate their operation with existing control devices, and mitigate undesired actuation of expensive equipment. Co-optimized operation of the various control devices becomes possible with the advancement in the power system optimization algorithms and the increased deployment of advanced metering infrastructure, offering system awareness and two-way communication. The steady-state alternating-current optimal power flow (ACOPF) problem, being the most descriptive form of OPF, lies at the root of power system optimization, aiming to minimize an operating …

Cancer Biomarker Detection In Human Plasma By Integrating Surface Acoustic Wave And Metal-Enhanced Fluorescence, Yuqi Huang

USF Tampa Graduate Theses and Dissertations

This thesis includes data and discussion about the technique of metal-enhanced fluorescence (MEF) to lower the detection limit of carcinoembryonic antigen (CEA). The detection limit goes down to 100pg/mL level when using MEF substrate made by rapid thermally annealed silver film covered by silica, which has great promise in diagnosing certain types of cancer that uses CEA as detection biomarker, such as pancreatic cancer and colon cancer. To further address the issue of background noises from non-specifically bound proteins (NSB) in complex media, such as plasma, serum, urine and blood, MEF is integrated with surface acoustic wave (SAW) streaming in …

Service Provisioning And Security Design In Software Defined Networks, Mohamed Rahouti

USF Tampa Graduate Theses and Dissertations

Information and Communications Technology (ICT) infrastructures and systems are being widely deployed to support a broad range of users and application scenarios. A key trend here is the emergence of many different "smart" technology paradigms along with an increasingly diverse array of networked sensors, e.g., for smart homes and buildings, intelligent transportation and autonomous systems, emergency response, remote health monitoring and telehealth, etc. As billions of these devices come online, ICT networks are being tasked with transferring increasing volumes of data to support intelligent real-time decision making and management. Indeed, many applications and services will have very stringent Quality of …

Investigation Of Navigation Systems For Size, Cost, And Mass Constrained Satellites, Omar Awad

USF Tampa Graduate Theses and Dissertations

The feasibility of using radically inexpensive micro-electromechanical system (MEMS) technology for navigation of a nanosatellite is investigated with a focus on attitude estimation. Typically, larger satellites are equipped with star cameras, sun sensors, or Earth horizon sensors for attitude estimation. These sensors can provide very accurate attitude measurements. A nanosatellite is highly size, power, and cost constrained and cannot readily accommodate these sensors. Our mission is to design, build, and operate a radically inexpensive nanosatellite system. While there is no consensus on what constitutes a "radically inexpensive" satellite, our goal is a maximum cost of $10,000 per unit. This precludes …

Socially Aware Network User Mobility Analysis And Novel Approaches On Aerial Mobile Wireless Network Deployment, Ismail Uluturk

USF Tampa Graduate Theses and Dissertations

Service demand patterns for wireless networks are evolving with the technological developments in areas such as personal computing, unmanned vehicles, and internet-of-things, where increasing mobile service demand is one of the significant challenges introduced. In addition to these new intrinsic dynamics, natural disasters and societal upheaval are also disrupting the conventional patterns of network demand. Situations like damaged infrastructure due to a natural disaster or large numbers of displaced people caused by political strife and social upheaval demand flexible, rapidly deployable network architectures. The increasing demands of next-generation communication services are straining the capabilities of the traditional approach of the …

Artificial Intelligence Towards The Wireless Channel Modeling Communications In 5g, Saud Mobark Aldossari

USF Tampa Graduate Theses and Dissertations

Channel prediction is a mathematical predicting of the natural propagation of the signal that helps the receiver to approximate the affected signal, which plays an important role in highly mobile or dynamic channels. The standard wireless communication channel modeling can be facilitated by either deterministic or stochastic channel methodologies. The deterministic approach is based on the electromagnetic theories and every single object in that environment has to be known in that propagation space and an example of this method is ray tracing. While the stochastic modeling method is based on measurements that involve statistical distributions of the channel parameters and …