Engineering Commons^™

A Statistical Analysis Of Sporadic-E Characteristics Associated With Gnss Radio Occultation Phase And Amplitude Scintillations, Daniel J. Emmons, Dong L. Wu, Nimalan Swarnalingam

Faculty Publications

Statistical GNSS-RO measurements of phase and amplitude scintillation are analyzed at the mid-latitudes in the local summer for a 100 km altitude. These conditions are known to contain frequent sporadic-E, and the S4-σ_ϕ trends provide insight into the statistical distributions of the sporadic-E parameters. Joint two-dimensional S4-σ_ϕ histograms are presented, showing roughly linear trends until the S4 saturates near 0.8. To interpret the measurements and understand the sporadic-E contributions, 10,000 simulations of RO signals perturbed by sporadic-E layers are performed using length, intensity, and vertical thickness distributions from previous studies, with the assumption that the sporadic-E layer acts …

Wireless Smart Electric Meter Operation Under Data Security Attacks, Patrick Nnaji, Harsh Kumar, Sanjeev Kumar

Electrical and Computer Engineering Faculty Publications

Wireless Smart meters are increasingly being deployed by the utility companies to remotely collect power consumption data from customer premise periodically in real time. It gives utility companies the information needed to efficiently administer their customers for their electricity usage. Knowing how critical these data are, it is important to ensure that data recorded locally at the smart meters or communicated remotely or wirelessly are both confidential and reliable. Despite the efforts being made to secure the smart meter data, security threats on smart meters continue to evolve at the same time, with an increasing number of security breaches happening …

Improvement For Mimo Systems By Increasing Antenna Isolation And Shaping Radiation Pattern Using Hybrid Network, Min Li, Yujie Zhang, Fan Jiang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, a novel method is proposed to design a hybrid network (HN) to increase isolation and shape radiation patterns for multiple-input multiple-output (MIMO) antenna systems. The HN is a combination of a decoupling feeding network and a defected ground network, which are populated by several surface-mounted reactive components whose reactances are determined by the N-ary optimization algorithm. Two decoupling examples are presented to validate the design methodology and elaborate on the design procedure. Measurement results show that the HN helps to realize impedance matching with reflection coefficients below -10 dB, isolation improvement from -5.4/-8.9 dB to below -20 …

Resistive Switching Characteristics Of Fullerene (C60) In Polymannose Thin Film, Kuan Yew Cheong, Ilias Ait Tayeb, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

The effects of C60 incorporated in polymannose-based resistive switching memory have been systematically investigated for the first time in bioorganic-based resistive switching memory. C60 with different concentrations (0–7 wt.%) is dispersed in polymannose precursor, drop-casted on ITO/PET substrate, and dried to form a thin film. Electrochemically inert Au–Pd is used as top electrode. The devices with embedded C60 show better endurance and stability. Read memory window decreases and ON/OFF ratio increases as the concentration of C60 increases. Stable retention time up to 10 years is achieved for all of the devices except the one with 7 wt.% C60. Based on …

A Fiber-Optic Sensor-Embedded And Machine Learning Assisted Smart Helmet For Multi-Variable Blunt Force Impact Sensing In Real Time, Yiyang Zhuang, Taihao Han, Qingbo Yang, Ryan O'Malley, Aditya Kumar, Rex E. Gerald, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

Early on-site diagnosis of mild traumatic brain injury (mTBI) will provide the best guidance for clinical practice. However, existing methods and sensors cannot provide sufficiently detailed physical information related to the blunt force impact. In the present work, a smart helmet with a single embedded fiber Bragg grating (FBG) sensor is developed, which can monitor complex blunt force impact events in real time under both wired and wireless modes. The transient oscillatory signal "fingerprint" can specifically reflect the impact-caused physical deformation of the local helmet structure. By combination with machine learning algorithms, the unknown transient impact can be recognized quickly …

Recycling Of Cured Carbon Fiber/Epoxy Resin Laminated Composites Scraps: Processing And Characterization, Khaled Mohammed Al Harmoodi

Theses

The concept of reinforced composites came decades ago from the need to fabricate high-strength, heat-resistant, wear-resistant, and low-density materials. The polymer matrix composites offer a wide range of applications due to the collaborative nature of the functional fillers and polymers present. Towards the twenty-first century, the aviation industry flourished due to flying being the preferred way of travel across states and countries. With such a massive demand for air transport, there is an equally parallel demand for the production of aircraft components. This study aims to reuse the waste of uncured composite prepreg scraps from the ply-cutting manufacturing process in …

Effects Of A Non-Uniform Magnetic Field On The Current Flow Of Silicon Photodiodes And Solar Cells, Jason J. Buranich

Theses and Dissertations

This research investigates an approach to improve efficiency of low-cost devices by applying an external arched magnetic field to p-n junction devices to observe the effect such a magnetic field would have on the flow of charge carriers. Electro-optic p-n junction devices of photodiodes and solar cells were designed and fabricated to incorporate the dimensions of commercially available neodymium magnets. The devices were placed in the magnetic fields created by the magnets then current and voltage characteristics were measured via a 4-point probe setup. These measurements were compared to measurements taken from the same devices when not in the magnetics …

Raman Scattering Measurements And Analyses Of Gan Thin Films Grown On Zno Substrates By Metalorganic Chemical Vapor Deposition, Zane Mcdaniel, Zhe Chuan Feng, Kevin Stokes

Symposium of Student Scholars

Metalorganic chemical vapor deposition (MOCVD) is a popularly used method of growing thin films of GaN on ZnO (GZ) substrates, which pair well due to their structural and characteristic similarities. In this research, optical characterization of the surface quality of GZ sample films is measured by analyzing Raman scattering (RS) using a Renishaw inVia spectrometer fitted with a 532nm laser. Samples were grown in an improved double injection block rotating disc reactor. Multiple samples' spectra show broad peaks that correspond with the E2 (high) and A1 (LO) branches of GaN, and nicely fitted curves are observed for the characteristic E2 …

Dynamic Perimeter Movement Using Uavs And Robotic Systems, Nayeli Barrett, John Lawson, Billy Kihei

Symposium of Student Scholars

For this study, we propose a Dynamic Perimeter Movement system that has a user-operated UAV to identify GPS coordinate points using land markers such as April Tags. These markers would be used to identify the perimeter of a road work zone. Once the work zone is determined, autonomous robotic traffic cones would disperse to position themselves around the perimeter determined by coordinate points. As the work zone progresses the UAV would periodically update the perimeter to reposition robotic traffic cones. These traffic cones will operate using a Pure Pursuit system as a means to navigate.

Parallel Distributed Compensation-Pid Controller Design For Maximum Power Point Tracking Of Dynamic Loaded Photovoltaic System, Anas Shomer, Helmy El Zoghby, Mohiy E. Bahgat, Soliman Sharaf

Future Engineering Journal

Control issues come from the output voltage of PV installations and systems operating in a range of irradiance and temperature. By using a DC converter, such systems are able to maintain a constant output voltage despite fluctuations in the generated voltage and load. The design of a maximum power point tracking (MPPT) on DC converter controller is presented in this article for a system. Fractional Order-Proportional Integral Derivative (FO-PID) and Parallel Distributed Compensation-Proportional Integral Derivative (PDC-PID) controllers have been implemented to the system converter as a proposed control approach. Particle Swarm Optimization (PSO) is used as optimization technique for determining …

Performance Comparison Of Several Control Algorithms For Tracking Control Of Pantograph Mechanism, Laylaa Mahmoud Eng, Mohamed Shamseldin Dr, Mohamed Sallam Dr, Abdelghany Mohamed Prof

Future Engineering Journal

A sort of parallel manipulator known as a pantograph robot mechanism was created primarily for industrial requests that required high precision and satisfied speed. While tracking a chosen trajectory profile requires a powerful controller. Because it has four active robot links and one robot passive link in place of just two links like the open chain does, it can carry more loads than the open chain robot mechanism while maintaining accuracy and stability. The calculated model for a closed chain pantograph robot mechanism presented in this paper takes into account the boundary conditions. For the purpose of simulating the dynamics …

Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany

Future Engineering Journal

Expanding the usage of renewable energy in islanded microgrids leads to a reduction in its total inertia. Low inertia microgrids have difficulties in voltage and frequency control. That affected saving its stability and preventing a blackout. To improve low inertia islanded microgrids' dynamic response and save their stability, this paper presented relative rate observer self-tuning fuzzy PID (RROSTF-PID) based on virtual inertia control (VIC) for an islanded microgrid with a high renewable energy sources (RESs) contribution. RROSTF-PID based on VIC's success in showing remarkable improvement in the microgrid's dynamic response and enhancement of its stability. Moreover, it handles different contingency …

Research On Stability And Resilience Of Modern Power Systems, Yi Zhou

USF Tampa Graduate Theses and Dissertations

With more and more renewable energy generation integrated into the utility grid, the modern power system circumstance and its operating characteristics have changed significantly. Since most renewable energy resources are inverter-based resources (IBR), the prominent characteristics of the power electronics and the cyber distribution in the renewable energy generation system make the power grid stability more diverse and complex.

This dissertation addresses the power system resilience problems from two points of view. The first one is from the inverter level, which deals with the problems of short circuit ratio (SCR) drop. With low SCR, the IBR system operation point may …

Cybersecurity And Dynamic Operation In Practice: Equipment Impacts And Safety Guarantees, Kip Nieman, Dominic Messina, Matthew Wegener, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Though dynamic operation of chemical processes has been extensively explored theoretically in contexts such as economic model predictive control or even considering the potential for cyberattacks on control systems creating non-standard operating policies, important practical questions remain regarding dynamic operation. In this work, we look at two of these with particular relevance to process safety: (1) evaluating dynamic operating policies with respect to process equipment fidelity and (2) evaluating procedures for determining the parameters of an advanced control law that can promote both dynamic operation as well as safety if appropriately designed. Regarding the first topic, we utilize computational fluid …

Efficient Interface Enabled By Nano-Hydroxyapatite@Porous Carbon For Lithium-Sulfur Batteries, Jia-Yu Wang, Xue-Feng Tong, Qi-Fan Peng, Yue-Peng Guan, Wei-Kun Wang, An-Bang Wang, Nai-Qiang Liu, Ya-Qin Huang

Journal of Electrochemistry

The dissolution and “shuttle effect” of lithium polysulfides (LiPSs) hinder the application of lithium-sulfur (Li-S) batteries. To solve those problems, inspired by natural materials, a nano-hydroxyapatite@porous carbon derived from chicken cartilage (nano-HA@CCPC) was fabricated by employing a simple pre-carbonization and carbonization method, and applied in Li-S batteries. The nano-HA@CCPC would provide a reactive interface that allows efficient LiPSs reduction. With a strong affinity for LiPSs and an excellent electronic conductive path for converting LiPSs, the shuttle effect of LiPSs was confined and the redox kinetics of LiPSs was substantially enhanced. Li-S batteries employing nano-HA@CCPC-modified separators exhibited long cycle life and …

Recognition Of Modern Modulated Waveforms With Applications To Abms And Vdats Test Program Set Development, Sylwester Sobolewski

USF Tampa Graduate Theses and Dissertations

A newly developed, near real-time, well-performing and potentially universally applicable Automatic Modulation Recognition (AMR) technique for discrimination of numerous modern modulated waveforms found in commercial as well as military communication systems applicable to the new Air Force’s Advanced Battle Management & Surveillance (ABMS) framework as well as Versatile Depot Automatic Test Station (VDATS) Test Program Set (TPS) development is presented. It involves generating complex feature vectors composed of High-Order Direct Cumulant, Cyclostationary and Fourier of Wavelet Transform features created with the help of Principal Component Analysis and Variance Data Compression.

Twelve modulated waveforms are used to evaluate the performance of …

Frequency Domain Diffuse Optics Spectroscopies For Quantitative Measurement Of Tissue Optical Properties, Sadhu Moka

USF Tampa Graduate Theses and Dissertations

Tissue oxygen saturation, blood flow and blood volume are physiological bio-markers of tissue health. Diffuse Optical Spectroscopy(DOS) and Diffuse Correlation Spectroscopy (DCS) are two complementary approaches to measure tissue oxygen saturation and blood flow respectively. Quantitative Diffuse Optical Spectroscopy (DOS) uses multi-spectral intensities of near-infrared light that have been modulated at RF frequencies to estimate static tissue optical properties and hence concentrations of oxygenated and de-oxygenated hemoglobin. Diffuse Correlation Spectroscopy estimates tissue dynamics - i.e., blood flow, by measuring temporal intensity auto-correlation function of backscattered light diffusing through the tissue. Conventionally, DCS instruments use coherent light sources with constant intensity. …

Reducing Instrumentation Barriers Of Diffuse Correlation Spectroscopy For Low-Cost Deep Tissue Blood Flow Monitoring, Arindam Biswas

USF Tampa Graduate Theses and Dissertations

Cerebral blood flow (CBF) is a good indicator of brain health as blood carries necessary nutrients, oxygen, and metabolic byproducts. Quantitative blood flow information can be used in several clinical and therapeutic applications such as stroke detection, measuring autoregulation, evaluating brain injury, or determining neuronal activity. Over the past few decades, light-based deep tissue hemodynamic detection modalities have become popular for non-invasive CBF measurements. In particular, noninvasive Diffuse Correlation Spectroscopy (DCS), has become a tool of choice for research and clinical applications due to its depth sensitivity (>1 cm), portability, validity against other technologies such as Magnetic Resonance Imaging …

Information Dissemination And Perpetual Network, Harshit Srivastava

USF Tampa Graduate Theses and Dissertations

Social networks have attracted increasing attention from both physical and social scientists. Social networks are essential elements in societies, serving as channels for exchanging various benefits, such as innovation, information, and social support. Moreover, research in social networks helps explain macro-level social phenomena, such as social polarization and social contagion. An understanding of social networks has significant implications, such as improving social welfare and political participation. Modeling social network formation has typically employed game theory or agent-based modeling. These studies typically propose simple and tractable micro-level rules for link formation mechanisms and show that these rules have implications for known …

Review On Oxygen-Free Vanadium-Based Cathodes For Aqueous Zinc-Ion Batteries, Xiao-Ru Yun, Yu-Fang Chen, Pei-Tao Xiao, Chun-Man Zheng

Journal of Electrochemistry

Aqueous zinc-ion batteries (AZIBs) are considered as one of the most promising next-generation electrochemical energy storage systems owing to their high-power density, environmental benign, intrinsic safety, and the low cost of the abundant zinc resources. However, their further development is still plagued by the inferior electrochemical performance of cathode materials. Though extensive research has been conducted to investigate various cathode materials (including manganese oxides, vanadium oxides, Prussian blues analogy, and organic materials), design of high-performance cathodes with satisfying capacity and long-term cycling stability still faces great challenges. Oxygen-free vanadium-based compounds, owing to their better conductivity, larger interlayer spacing, lower ion …

Which Factor Dominates Battery Performance: Metal Ion Solvation Structure-Derived Interfacial Behavior Or Solid Electrolyte Interphase Layer?, Hao-Ran Cheng, Zheng Ma, Ying-Jun Guo, Chun-Sheng Sun, Qian Li, Jun Ming

Journal of Electrochemistry

Solid-electrolyte interphase (SEI) layer formed on the electrode by electrolyte decomposition has been considered to be one of the most important factors affecting the battery performance. We discover that the metal ion solvation structure can also influence the performance, particularly, it can elucidate many phenomena that the SEI cannot. In this review, we summarize the importance of the metal ion solvation structure and the derived metal ion de-solvation behaviors, by which we can build an interfacial model to show the relationship between the interfacial behavior and electrode performance, and then apply to different electrode and battery systems. We emphasize the …

Advances And Atomistic Insights Of Electrolytes For Lithium-Ion Batteries And Beyond, Tingzheng Hou, Xiang Chen, Lu Jiang, Cheng Tang

Journal of Electrochemistry

Electrolytes and the associated electrode-electrolyte interfaces are crucial for the development and application of high-capacity energy storage systems. Specifically, a variety of electrolyte properties, ranging from mechanical (compressibility, viscosity), thermal (heat conductivity and capacity), to chemical (solubility, activity, reactivity), transport, and electrochemical (interfacial and interphasial), are correlated to the performance of the resultant full energy storage device. In order to facilitate the operation of novel electrode materials, extensive experimental efforts have been devoted to improving these electrolyte properties by tuning the physical design and/or chemical composition. Meanwhile, the recent development of theoretical modeling methods is providing atomistic understandings of the …

Insight Into The Effects Of Cation Disorder And Surface Chemical Residues On The Initial Coulombic Efficiency Of Layered Oxide Cathode, Jin-Li Liu, Han-Feng Wu, Zhi-Bei Liu, Ying-Qiang Wu, Li Wang, Feng-Li Bei, Xiang-Ming He

Journal of Electrochemistry

Lithium layered oxide LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) is one of the most promising cathode materials in high-energy lithium-ion batteries for electric vehicles. However, one drawback for NCM622 is that its initial coulombic efficiency (ICE) is only about 87%, which is at least 6% lower than that of LiCoO₂ or LiFePO₄. In this work, we investigated the effects of surface chemical residues (e.g., LiOH and Li₂CO₃) and Li/Ni cation disorder resulted during the sintering on the ICE. We found that the ICE of the as-prepared samples could be boosted …

Modeling, Control, And Operation Of A Grid-Tied Solar Photovoltaic Inverter In Unbalanced Conditions, Abdulhakim Alsaif

USF Tampa Graduate Theses and Dissertations

With the increasing penetration of inverter-based resources (IBRs) integrated into powersystem grids as well as in microgrids (MGs), operational challenges and stability issues have been identified by the industry. In the last few years, solar Photovoltaic (PV) farm plants were allowed to be disconnected (isolated from the grid) during abnormal operation conditions to not only avoid stability issues but also to protect any damage to the solar PV inverter from such overcurrent or overvoltage. Most solar PV inverters operate in a conventional grid-following (GFL) control, where unbalanced operation becomes a critical issue. This control scheme regulates only positive sequence currents. …

Dynamic Study Of Inverter-Based Resources In Weak Grids, Zhengyu Wang

USF Tampa Graduate Theses and Dissertations

As the main technology behind renewable energy resources, such as solar PV and wind turbines, inverter-based generation penetration is increasing aggressively. Besides the congestion concerns when interconnecting a large-scale inverter-based resource (IBR) into the power grid, stability issues are commonly existing. The stability events occur more frequently when the resources are in remote area because the transmission line is long and grid strength is weak. One of the most representative and widely observed phenomena of IBR instability is low-frequency oscillation. And this dissertation focuses on investigating the low-frequency oscillations of IBR in weak grids.

The main objectives of the investigation …

Cocm: Co-Occurrence-Based Consistency Matching In Domain-Adaptive Segmentation, Siyu Zhu, Yingjie Tian, Fenfen Zhou, Kunlong Bai, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

This paper focuses on domain adaptation in a semantic segmentation task. Traditional methods regard the source domain and the target domain as a whole, and the image matching is determined by random seeds, leading to a low degree of consistency matching between domains and interfering with the reduction in the domain gap. Therefore, we designed a two-step, three-level cascaded domain consistency matching strategy—co-occurrence-based consistency matching (COCM)—in which the two steps are: Step 1, in which we design a matching strategy from the perspective of category existence and filter the sub-image set with the highest degree of matching from the image …

Passive Cooling Analysis Of An Electronic Chipset Using Nanoparticles And Metal-Foam Composite Pcm: An Experimental Study, Faisal Hassan, Abid Hussain, Furqan Jamil, Adeel Arshad, Hafiz Muhammad Ali

Research outputs 2022 to 2026

Thermal management of electronic components is critical for long-term reliability and continuous operation, as the over-heating of electronic equipment leads to decrement in performance. The novelty of the current experimental study is to investigate the passive cooling of electronic equipment, by using nano-enriched phase change material (NEPCM) with copper foam having porosity of 97 %. The phase change material of PT-58 was used with graphene nanoplatelets (GNPs) and magnesium oxide (MgO) nanoparticles (NPs), having concentrations of 0.01 wt. % and 0.02 wt. %. Three power levels of 8 W, 16 W, and 24 W, with corresponding heating inputs of 0.77 …

A Patient-Specific Algorithm For Lung Segmentation In Chest Radiographs, Manawaduge Supun De Silva, Barath Narayanan Narayanan, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

Lung segmentation plays an important role in computer-aided detection and diagnosis using chest radiographs (CRs). Currently, the U-Net and DeepLabv3+ convolutional neural network architectures are widely used to perform CR lung segmentation. To boost performance, ensemble methods are often used, whereby probability map outputs from several networks operating on the same input image are averaged. However, not all networks perform adequately for any specific patient image, even if the average network performance is good. To address this, we present a novel multi-network ensemble method that employs a selector network. The selector network evaluates the segmentation outputs from several networks; on …

Computer Engineering Education, Marilyn Wolf

School of Computing: Conference and Workshop Papers

Computer engineering is a rapidly evolving discipline. How should we teach it to our students?

This virtual roundtable on computer engineering education was conducted in summer 2022 over a combination of email and virtual meetings. The panel considered what topics are of importance to the computer engineering curriculum, what distinguishes computer engineering from related disciplines, and how computer engineering concepts should be taught.

Digitally Predicting Protein Localization And Manipulating Protein Activity In Fluorescence Images Using 4d Reslicing Gan, Yang Jiao, Lingkun Gu, Yingtao Jiang, Mo Weng, Mei Yang

Electrical & Computer Engineering Faculty Research

While multi-channel fluorescence microscopy is a vital imaging method in biological studies, the number of channels that can be imaged simultaneously is limited by technical and hardware limitations such as emission spectra cross-talk. One solution is using deep neural networks to model the localization relationship between two proteins so that the localization of one protein can be digitally predicted. Furthermore, the input and predicted localization implicitly reflect the modeled relationship. Accordingly, observing the response of the prediction via manipulating input localization could provide an informative way to analyze the modeled relationships between the input and the predicted proteins.