Electrical and Computer Engineering Commons^™

Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang

Journal of Electrochemistry

Sulfurized polyacrylonitrile (SPAN) is regarded as an attractive cathode candidate of lithium-sulfur (Li-S) batteries for its non-dissolution mechanism and effective alleviation of polysulfides shuttling issue in Li-S batteries, displaying high utilization of cathode active material, outstanding cycle stability and structural stability. However, the relation between cyclization degree and cycle stability of SPAN is still unveiled. In this work, SPAN-C-V composites were synthesized by co-introduction of CuSO₄ and zinc n-ethyl-n-phenyldithiocarbamate (ZDB) in the co-heating of sulfur and polyacrylonitrile. The co-introduction of CuSO₄ and ZDB reduced the cyclization reaction onset temperature of PAN while increased the C—C/C=C within SPAN-C-V, thus …

Emergence Of Coherent Backscattering From Sparse And Finite Disordered Media, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri, Theodore B. Norris

Engineering Faculty Articles and Research

Coherent backscattering (CBS) arises from complex interactions of a coherent beam with randomly positioned particles, which has been typically studied in media with large numbers of scatterers and high opacity. We develop a first-principles scattering model for scalar waves to study the CBS cone formation in finite-sized and sparse random media with specific geometries. The current study provides insights into the effects of density, volume size, and other relevant parameters on the angular characteristics of the CBS cone emerging from sparse and bounded random media for various types of illumination, with results consistent with well-known CBS studies which are typically …

Weakly-Supervised Learning Method For The Recognition Of Potato Leaf Diseases, Junde Chen, Xiaofang Deng, Yuxin Wen, Weirong Chen, Adnan Zeb, Defu Zhang

Engineering Faculty Articles and Research

As a crucial food crop, potatoes are highly consumed worldwide, while they are also susceptible to being infected by diverse diseases. Early detection and diagnosis can prevent the epidemic of plant diseases and raise crop yields. To this end, this study proposed a weakly-supervised learning approach for the identification of potato plant diseases. The foundation network was applied with the lightweight MobileNet V2, and to enhance the learning ability for minute lesion features, we modified the existing MobileNet-V2 architecture using the fine-tuning approach conducted by transfer learning. Then, the atrous convolution along with the SPP module was embedded into the …

Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew

Dissertations and Theses

A Modular Multilevel Converter (MMC) is an attractive candidate in high power conversion due to its modularity and scalability. The energy storage element, namely the module capacitance in the MMC submodule circuit, is typically large and when scaled to convert high power, requires very bulky module capacitors. In addition to deteriorating the power density, the design necessitates the use of electrolytic capacitors, which further affects the overall converter efficiency and reliability. This research presents an MMC submodule topology and the accompanying modulation approach that reduces the submodule capacitance requirements significantly compared to conventional MMC topology (few micro-farads versus several milli-farads). …

Application Of Distributed Fiber-Optic Sensing For Pressure Predictions And Multiphase Flow Characterization, Gerald Kelechi Ekechukwu

LSU Doctoral Dissertations

In the oil and gas industry, distributed fiber optics sensing (DFOS) has the potential to revolutionize well and reservoir surveillance applications. Using fiber optic sensors is becoming increasingly common because of its chemically passive and non-magnetic interference properties, the possibility of flexible installations that could be behind the casing, on the tubing, or run on wireline, as well as the potential for densely distributed measurements along the entire length of the fiber. The main objectives of my research are to develop and demonstrate novel signal processing and machine learning computational techniques and workflows on DFOS data for a variety of …

Towards Robust Channel Dynamics: Photoionization In Nitrogen And Air, Justin K. Smith

Electrical and Computer Engineering ETDs

In present photoionization models used in computational studies, there is a lack of experimental data and several assumptions pertaining to photo-electron production in the gas. It is widely accepted that wavelengths between 98 nm and 102.5 nm are the primary contributors to photoionization of oxygen in an air plasma. In air, the collisional kinetics of nitrogen provide the photons, which results in the ionization of oxygen. Photoionization rate measurements from a low current corona discharge in synthetic air mixtures are reported to provide new empirical data. In addition, this provides a method to estimate the scaling parameter w/a. Concurrently, vacuum …

A Horn Microstrip Transmission Line For The Characterization And Investigation Of Multipactor At Various Pressure And Power, Shaho Hamadamin

Electrical and Computer Engineering ETDs

The University of New Mexico is designing, building, and testing a multipactor testbed based on a horn-microstrip transmission line to characterize and investigate the multipactor effect for a range of vacuum pressures and power. A horn-shaped, 50 Ω Al microstrip line is positioned inside a six-way cross stainless-steel chamber that is vacuumed down to low ~10−7 torr. A 100 𝑀𝑀𝑀𝑀𝑀𝑀 sine signal is fed to a rf amplifier with a bandwidth of 250 − 105 𝑀𝑀𝑀𝑀𝑀𝑀, that can reach 120𝑊𝑊 average (CW) power. Two multipacting detection methods, i.e., global, and local methods, are implemented for accurate multipaction detection. The former …

Protection And Control Of Electric Power Grid Under High Penetration Of Ders, Binod Prasad Poudel

Electrical and Computer Engineering ETDs

Modernizing power grids with communication-based technologies has introduced new challenges to the operation of the grid, especially when the communication network experiences failure or data is corrupted during the transfer. This issue is studied in this dissertation from the control and protection perspective. First, the cyber attack detection and mitigation of distributed control of microgrids is addressed when the distributed energy resources (DER) are exposed to false data injection attacks. A cyber-threat detection technique is proposed based on Kullback-Liebler divergence-based criterion. This criterion with a threshold can detect the misbehavior of a compromised DER control unit and, consequently, calculates the …

Towards Multipronged On-Chip Memory And Data Protection From Verification To Design And Test, Senwen Kan, Jennifer Dworak

Computer Science and Engineering Theses and Dissertations

Modern System on Chips (SoCs) generally include embedded memories, and these memories may be vulnerable to malicious attacks such as hardware trojan horses (HTHs), test access port exploitation, and malicious software. This dissertation contributes verification as well as design obfuscation solutions aimed at design level detection of memory HTH circuits as well as obfuscation to prevent HTH triggering for embedded memory during functional operation. For malicious attack vectors stemming from test/debug interfaces, this dissertation presents novel solutions that enhance design verification and securitization of an IJTAG based test access interface. Such solutions can enhance SoC protection by preventing memory test …

An Efficient Integrated Circuit Simulator And Time Domain Adjoint Sensitivity Analysis, Jiahua Li

Electrical Engineering Theses and Dissertations

In this paper, we revisit time-domain adjoint sensitivity with a circuit theoretic approach and an efficient solution is clearly stated in terms of device level. Key is the linearization of the energy storage elements (e.g., capacitance and inductance) and nonlinear memoryless elements (e.g., MOS, BJT DC characteristics) at each time step. Due to the finite precision of computation, numerical errors that accumulate across timesteps can arise in nonlinear elements.

In Band Full Duplex For Wireless Communication, A Medium Access Control Perspective, Yazeed Alkhrijah

Electrical Engineering Theses and Dissertations

In-band full duplex (IBFD) for wireless communication is defined as the ability of a node to send and receive data simultaneously by using the same frequency band. IBFD has the potential to double the spectral efficiency of wireless networks. In addition, IBFD improves security by mystifying any eavesdropper with multiple transmitted signals in a single frequency. Also, IBFD reduces the end-to-end transmission delay and solves the hidden terminal and exposed terminal problems. However, IBFD suffers from self-interference. Canceling self-interference (SI) is the main challenge in enabling IBFD. Another challenge for IBFD is to manage access to the network. IEEE802.11 are …

Novel Locomotion Methods In Magnetic Actuation And Pipe Inspection, Adam Cox

Mechanical Engineering Research Theses and Dissertations

There is much room for improvement in tube network inspections of jet aircraft. Often, these inspections are incomplete and inconsistent. In this paper, we develop a Modular Robotic Inspection System (MoRIS) for jet aircraft tube networks and a corresponding kinematic model. MoRIS consists of a Base Station for user control and communication, and robotic Vertebrae for accessing and inspecting the network. The presented and tested design of MoRIS can travel up to 9 feet in a tube network. The Vertebrae can navigate in all orientations, including smooth vertical tubes. The design is optimized for nominal 1.5" outside diameter tubes. We …

Orbital Angular Momentum Orthogonality-Based Crosstalk Reduction: Theory And Experiment, Unaiza Tariq

Electrical Engineering Theses and Dissertations

Full duplex communication systems allow a single channel to be used for simultaneous two-way communication, increasing spectral efficiency. However, full duplex communication systems suffer from the issue of self-interference between local transmitter and receiver antennas. Analog subtraction and signal processing methods have previously been used to reduce this problem. This dissertation proposes the use of waves carrying orbital angular momentum (OAM) to mitigate the problem of self-interference by offering a means of additional isolation between local antennas.

Orbital angular momentum has been widely studied both in the photonics and radio domain. The theoretically infinite orthogonal states of an OAM signal …

Distribution Network Operation With Solar Photovoltaic And Energy Storage Technology, Mohammad Ramin Feizi

Electrical Engineering Theses and Dissertations

Among distributed energy resources, solar photovoltaic (PV) generation has the largest penetration in the distribution networks. Serving electric vehicles (EV) with renewable resource generation would further reduce the carbon footprint of the energy supply chain for electric vehicles. However, the integration of solar PV and EVs in the unbalanced distribution network introduces several challenges including voltage fluctuations, voltage imbalances, reverse power flow, and protection devices’ malfunctions. The uncertainties associated with solar PV integration and electric vehicles operation require significant effort to develop accurate optimization methodologies in the unbalanced distribution systems operation. In this thesis, in order to cope with the …

Development And Application Of A Design Flow For Photonic Integrated Circuits, Ifeanyi Achu

Electrical Engineering Theses and Dissertations

Silicon photonics allows for the fabrication of many optical elements on a single photonic integrated circuit (PIC). By taking advantage of the established foundry technology used in the CMOS and silicon’s high refractive index, high feature density manufacturing can be achieved in mass quantities. In CMOS fabrication, from conception of an electronic circuit to testing, the process of designing an electronic circuit is dictated by a design flow which has been developed over the course of decades. This flow includes circuit level design and simulation, layout of the circuit, layout and verification of the chip, fabrication, packaging, and testing. Given …

Void-Semiconductor Gaas Photonic Crystal Surface-Emitting Lasers By Epitaxial Regrowth And Single-Epitaxy Methods, Kevin James Reilly

Nanoscience and Microsystems ETDs

Monolithic semiconductor lasers including edge-emitting lasers (EELs) and vertical-cavity surface-emitting lasers (VCSELs) fail to realize simultaneous achievement of both high-power high-quality beams due to intrinsic limitations of their resonant cavity. Photonic crystal surface emitting lasers (PCSELs) address these structural limitations through employment of a two-dimensional photonic crystal (PC) cavity that creates feedback at a single wavelength for laterally scalable devices. This function of the PC allows PCSELs to power scale with area while maintaining single-mode emission required for diffraction-limited beams. In this way, PCSELs fulfill an industry demand for high-power high-quality lasing from a single chip.

Early PCSELs were fabricated …

Cyber-Secure Distributed Control Of Microgrids With Improved Communication And Control Protocols, Jee Won Choi

Mechanical Engineering ETDs

This dissertation proposes a cyber-secure distributed control of microgrids with improved communication and control protocols. The finite-time event-triggered control protocol for islanded AC and DC secondary control is introduced. For AC microgrids, the proposed strategy can effectively perform frequency restoration and voltage regulations while sharing the active and reactive power among the distributed generators (DGs) based on their power ratings. For DC microgrids, the proposed control protocol can provide accurate current sharing and critical bus voltage regulation. The finite-time control enables a system to reach a consensus in a finite period of time enhanced from asymptotic convergence. The event-triggered communication …

Digital Platform To Aid Youth Substance Abuse Prevention, Bingxuan Li

Discovery Undergraduate Interdisciplinary Research Internship

Through research and interviews, I discovered that a significant portion of students in Africa become drug addicts and drop out of school. The solution is to prevent youth substance abuse before it happens, so that more students in Africa may continue their education. With the strong motivation of expanding African student involvement in higher education, I participated DURI program to increase higher education rates in the Democratic Republic of the Congo, Africa. The local government is establishing rehabilitation centers to monitor at-risk students and prevent youth substance abuse, but due to extremely limited resources, it is critical to evaluate the …

Reinforcement Learning-Based Demand Response Management In Smart Grid Systems With Prosumers, Jenilee Jao

Electrical and Computer Engineering ETDs

In this thesis, we introduce a reinforcement learning-based price-driven Demand Response Management (DRM) mechanism in smart grid systems consisting of prosumers. Our proposed approach accounts for the prosumers behavioral characteristics and models the emerging interactions among all the involved actors in the smart grid system, i.e., prosumers, Energy Management System (EMS) and utility companies. In particular, an off-policy reinforcement learning is introduced enabling the EMS to determine the optimal price that should be announced to the prosumers on an hourly-basis towards minimizing the overall systems cost. In this process, the utility companies hourly-based wholesale price and the prosumers energy generation …

Data-Driven Power System Stability Analysis And Control, Jian Xie

Electronic Theses and Dissertations, 2020-2023

In recent years, with the expansion of power system size, the increase of interconnection and the use of large-scale renewable energy, power system stability and safe operations have become more prominent, causing challenges to the normal operation of power grid. Traditional analysis rely on detailed models of the system. But for real power systems, the operating state of the system is variable, and the model-based analysis methods may not accurately reflect the real operating state of the system. Therefore, this dissertation is focused on data-driven stability analysis and control. First, a method for locating the oscillation source of multi-machine systems …

Leveraging Fpga Primitives To Improve Word Reconstruction During Netlist Reverse Engineering, Reilly Mckendrick, Corey Simpson, Brent Nelson, Jeffrey Goeders

Faculty Publications

While attempting to perform hardware trojan detection, or other low-level design analyses, it is often necessary to inspect and understand the gate-level netlist of an implemented hardware design. Unfortunately this process is challenging, as at the physical level, the design does not contain any hierarchy, net names, or word groupings. Previous work has shown how gate-level netlists can be analyzed to restore high-level circuit structures, including reconstructing multi-bit signals, which aids a user in understanding the behavior of the design. In this work we explore improvements to the word reconstruction process, specific to FPGA platforms. We demonstrate how hard-block primitives …

Distributed Detection In Energy Harvesting Wireless Sensor Networks, Ghazaleh Ardeshiri

Electronic Theses and Dissertations, 2020-2023

A conventional wireless sensor networks (WSN), consisting of sensors powered by nonrechargeable batteries, has a strictly limited lifetime. Energy harvesting (EH) from the environment is a promising solution to address the energy constraint problem in conventional WSNs, and to render these networks to self-sustainable networks with perpetual lifetimes. In EH-powered WSNs, where sensors are capable of harvesting and storing energy, power control is necessary to balance the rates of energy harvesting and energy consumption for data transmission. In addition, wireless communication channels change randomly in time due to fading. These together prompt the need for developing new power control strategies …

On-Board Artificial Intelligence For Failure Detection And Safe Trajectory Generation, Eduardo Morillo

Doctoral Dissertations and Master's Theses

The use of autonomous flight vehicles has recently increased due to their versatility and capability of carrying out different type of missions in a wide range of flight conditions. Adequate commanded trajectory generation and modification, as well as high-performance trajectory tracking control laws have been an essential focus of researchers given that integration into the National Air Space (NAS) is becoming a primary need. However, the operational safety of these systems can be easily affected if abnormal flight conditions are present, thereby compromising the nominal bounds of design of the system's flight envelop and trajectory following. This thesis focuses on …

Data-Driven Estimation Of The Power Grid Inertia With Increased Levels Of Renewable Generation Resources, Che Kai Chang

Theses - ALL

The thesis investigates methods for estimating inertia in systems at different levels of renewable energy penetrations. Estimating renewable generators' inertia is challenging because their structures differ from traditional generators. Moreover, the power generated from renewable energy resources is not stable, depending on weather conditions. When a power grid has a disturbance, photovoltaic inverter control influences a power grid inertia by different controllers, such as power factor and reactive power control, to bring a power grid back to a steady state. The changing reactive power impacts the frequency, which strongly relates to inertia and increases the inertia estimation problem.

Several papers …

Design Of Two Stage Bulk-Driven Operational Transconductance Amplifier (Ota) With A High Gain For Low Voltage Application, Pushkar N. Mishra

Theses - ALL

An Operational Transconductance Amplifier (further abbreviated as OTA) is a voltage controlled current source used to produce an output current proportional to the input voltage. A schematic architecture for a 180nm OTA is presented in this thesis with the goal of improving the open-loop gain for a 0.9V supply voltage with a rail-to-rail bulk-driven input stage. Results show an open loop gain 97.14 dB with a power consumption of 3.33uW. An OTA with over 90 dB open loop gain and lower power consumption is highly suitable for low-voltage applications. The slew rate of the OTA is 0.05V/uS with a unity-gain …

Television White Space Based Broadband Network’S Coverage And Capex Performance For Rural Areas Connectivity In Tanzania, Moses Ismail

Tanzania Journal of Engineering and Technology (TJET)

This study compared the CAPEX requirements for a television white space (TVWS) based broadband network and that of deploying the UMTS based mobile broadband networks to deliver broadband connectivity in areas with sparse population which characterize most of Tanzania rural. Like many developing countries, Tanzania has low Internet penetration, with penetration of just over 46% when multiple subscriptions are taken into account. The affected communities are mostly rural due to low population densities which make deployment of the mobile broadband to be much expensive in terms of costs. This limits the economic development potential in these areas given that the …

Iot-Based Smart Fishing Gear For Sustainability Of The Tanzania Blue Economy, Abdi Abdalla

Tanzania Journal of Engineering and Technology (TJET)

The fishing industry engages many Tanzanians and is among the leading sectors of Blue Economy in the country. However, fishing practices are small-scale with poor and insufficient number of fishing facilities, hence limiting productivity and efficacy. Studies argue that the low level of technology currently used in the country could possibly be an impeding factor. Specifically, fishers use non interactive gears that cannot instantaneously update status and alert them whenever the gears are ready for collection. In such scenarios, fishers not only waste their time but also scarce resources such as fuel to facilitate trips to and from the fishing …

The Use Of Online Social Media Platforms By Tanzania Journalists To Produce And Disseminate Development News, Elisha Magolanga

Tanzania Journal of Engineering and Technology (TJET)

Advancement in Information and Communication Technologies (ICT) are revolutionizing Development Journalism (DJ) into an effective strategy for building competitive economies globally. However, many countries in Africa including Tanzania are slow in tapping potentials of ICT for development journalism. Digital penetration in the form of the Internet and social media are changing the way in which journalists are mobilizing and engaging communities in journalism practises, a key strategy for a competitive digitalised economy. This paper was guided by Development Communication Theory and Diffusion of Innovation Theory to explore the use of online social media by journalists in Tanzania to practice development …

Development Of Directed Randomization For Discussing A Minimal Security Architecture, Henrique Oyama, Dominic Messina, Keshav Kasturi Rangan, Akkarakaran Francis Leonard, Kip Nieman, Helen Durand, Katie Tyrrell, Katrina Hinzman, Michael Williamson

Chemical Engineering and Materials Science Faculty Research Publications

Strategies for mitigating the impacts of cyberattacks on control systems using a control-oriented perspective have become of greater interest in recent years. Our group has contributed to this trend by developing several methods for detecting cyberattacks on process sensors, actuators, or both sensors and actuators simultaneously using an advanced optimization-based control strategy known as Lyapunov-based economic model predictive control (LEMPC). However, each technique comes with benefits and limitations, both with respect to one another and with respect to traditional information technology and computer science-type approaches to cybersecurity. An important question to ask, therefore, is what the goal should be of …

Establishment And Mapping Of Heterogeneous Anomalies In Network Intrusion Datasets, Liam Riddell, Mohiuddin Ahmed, Paul Haskell-Dowland

Research outputs 2022 to 2026

Anomaly detection in the scope of network security aims to identify network instances for the unexpected and unique, with various security operations employing such techniques to facilitate effective threat detection. However, many systems have been designed based on the absolute mapping of attacks to one of three anomaly types (i.e. point, collective, or contextual), a strategy not supported by the recent findings of hybrid anomaly classifications. Given the growing usage of network anomaly detection and the implications of hybrid anomalies, we propose several heterogeneous anomaly types and provide an unsupervised approach for the automated mapping of network threats. Initial findings …