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2025

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A Framework For Tailored Organisational Cyber Security Training, Zinnar Ghasem Jan 2025

A Framework For Tailored Organisational Cyber Security Training, Zinnar Ghasem

School of Engineering, Computing and Mathematics Theses

Zinnar Ahmed Ghasem A framework for tailored organisational cyber security training AbstractSociety is increasingly becoming dependent on cyberspace; in such it is becoming an integral part of every-day life of most people in both work and home context. This dependency spans across individuals, businesses, and organisations including governments who are relying on cyberspace for various services, ranging from email to social networking, and from cloud computing to ecommerce and financial automated process and transactions. These services are vulnerable and face sophisticated cyber threats, risks and attacks, and potentially can result in financial losses and compromise the confidentiality, integrity, and availability …

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Metamorphosis: An Evaluation Of The Adaptation And Re-Use Potential Of Suburban Housing For Older Homeowners, Michelle Moore Jan 2025

Metamorphosis: An Evaluation Of The Adaptation And Re-Use Potential Of Suburban Housing For Older Homeowners, Michelle Moore

Masters

Ireland’s population is ageing at a rate that is more than twice the EU average. Public policy in Ireland aims to support older persons to age-in-place. Over 80% of older adults in Ireland live in an owner-occupied home, following many decades of public policy promoting home ownership as the tenure of choice. Limited research has been undertaken on the housing adaptation options that could result in privately-owned homes being made more suitable for the evolving needs of the rapidly ageing demographic. This thesis addresses the hypothesis that, with the provision of an appropriate suite of enablers, older homeowners can be …

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Predictive Perception In Autism, Robert Harlow Jan 2025

Predictive Perception In Autism, Robert Harlow

School of Psychology Theses

This thesis investigates how predictive perception, motor coordination, and neurotype differences influences social perception in autism. It explores how these mechanisms contribute to social difficulties faced by autistic people, through the lens of the double empathy problem and second-person neuroscience.Chapter 2 examined how spoken intentions and visual evidence guide predictive social perception. Across four experiments, results supported a dual-process model whereby top-down expectations shape early perception but are overridden by visual input once motion begins. This led to the ‘kinematic dominance hypothesis’, suggesting motion cues dominate perception once movement begins due to their higher precision.Chapter 3 used high-resolution active motion …

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Bridging The Gap: A Mixed Methods Study Of Trainee Clinical Psychologists’ Experiences And Learning Needs For Working With Refugees, With Co-Produced Training Guidelines., Megan Stuart-Richards Jan 2025

Bridging The Gap: A Mixed Methods Study Of Trainee Clinical Psychologists’ Experiences And Learning Needs For Working With Refugees, With Co-Produced Training Guidelines., Megan Stuart-Richards

School of Psychology Theses

AbstractRefugees face unique and traumatising challenges to their mental health across multiple socio-political climates. Services are providing inequitable support for refugees, which lack appreciation of transcultural conceptualisations of mental distress, amongst a backdrop of social injustice. Refugees were employed as Co-researchers to co-produce every stage of this project. Reflexive Thematic Analysis was utilised in this study to examine experiences and learning needs of 79 Trainee Clinical Psychologists (TCP’s) in their survey responses. Novel training guidelines, to be accessed via ‘supplementary materials’, were co-produced alongside scoped learning needs, which contribute to health research and practice. Four interrelated overarching themes became evident. …

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From Feedback To Framework: Exploring A Student-Centric Development Process For Low-End Immersive Ar/Vr Learning Content In Hospitality Education, Alexander Lennart Schmidt, Praneschen Govender, Jeroen Oskam, Ralf Burbach, Davin Dunlea, Jennifer Hussey, Colin O’Connor, Daniel King, Pasi Tuominen, Jouko Loijas, Teemu Moilanen, Elisa Laatikainen, David Cortés, Belén Bermejo, Carlos Juiz Jan 2025

From Feedback To Framework: Exploring A Student-Centric Development Process For Low-End Immersive Ar/Vr Learning Content In Hospitality Education, Alexander Lennart Schmidt, Praneschen Govender, Jeroen Oskam, Ralf Burbach, Davin Dunlea, Jennifer Hussey, Colin O’Connor, Daniel King, Pasi Tuominen, Jouko Loijas, Teemu Moilanen, Elisa Laatikainen, David Cortés, Belén Bermejo, Carlos Juiz

Research Outputs: 2025-Present

There is a vibrant debate concerning the integration of immersive learning content into hospitality education to (a.) embed the learning process in real-life professional contexts and, (b.) uphold student engagement. Contributing to this debate, this article explores the development process of low-end immersive AR/VR content for hospitality education, leveraging design-based research (DBR) centered around student feedback. This study is based on qualitative focus group data triangulated with survey data collected across four universities located in Europe, each of which offers hospitality programs. Our findings suggest a three-stage development process framework. This process comprises three decision-making dilemmas which need to be …

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The Digital Loophole: Evaluating The Effectiveness Of Child Age Verification Methods On Social Media, Fatmaelzahraa Eltaher Ph.D, Rahul Gajula, Luis Miralles-Pechuán, Christina Thorpe, Susan Mckeever Jan 2025

The Digital Loophole: Evaluating The Effectiveness Of Child Age Verification Methods On Social Media, Fatmaelzahraa Eltaher Ph.D, Rahul Gajula, Luis Miralles-Pechuán, Christina Thorpe, Susan Mckeever

Conference papers

Social media platforms are an integral part of daily life for nearly five billion people worldwide. However, the growing presence of underage users on these platforms raises significant concerns regarding children's exposure to harmful content and its impact on their mental health. This paper examines the effectiveness of age verification measures implemented on leading platforms Facebook, YouTube, Instagram, TikTok, Snapchat, and X. We evaluate the age verification processes required for account creation by simulating the registration steps for minors on these platforms. We also compare these methods to best practices in online age assurance in finance, betting and public transportation …

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Synthesising Cross-Speaker Data For Low-Resource Pathological Speech Recognition With Peft, Kesego Mokgosi, Milad Dadgar, Cathy Ennis, Robert Ross Jan 2025

Synthesising Cross-Speaker Data For Low-Resource Pathological Speech Recognition With Peft, Kesego Mokgosi, Milad Dadgar, Cathy Ennis, Robert Ross

Conference papers

Dysarthric speech recognition is essential for enhancing communication and accessibility for individuals with speech impairments, yet its development is hindered by a scarcity of robust, speaker-specific datasets. This study explores low-resource dysarthric speech recognition through cross-speaker transfer using synthetic data and parameter-efficient fine-tuning (PEFT). We integrate SpeechT5 text-to-speech (TTS) synthesis with x-vector speaker embeddings to generate speaker-specific dysarthric speech, enabling model adaptation while preserving pathological speech characteristics such as prosodic irregularities. Experiments on the TORGO dataset show that mixed cross-synthetic data with LoRA fine-tuning achieves a WER of 0.17, representing a 71.7% improvement over the standard model (0.60 WER) without …

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Integration Of The Portionsize Ed App Into Snap-Ed For Improving Diet Quality Among Adolescents In Hawaii: A Randomized Pilot Study, Emerald S. Proctor, Kiari H.L. Aveiro, Ian Pagano, Lynne R. Wilkens, Leihua Park, Leilani Spencer, Jeannie Butel, Corby K. Martin, John W. Apolzan, Rachel Novotny, John Kearney, Chloe P. Lozano Jan 2025

Integration Of The Portionsize Ed App Into Snap-Ed For Improving Diet Quality Among Adolescents In Hawaii: A Randomized Pilot Study, Emerald S. Proctor, Kiari H.L. Aveiro, Ian Pagano, Lynne R. Wilkens, Leihua Park, Leilani Spencer, Jeannie Butel, Corby K. Martin, John W. Apolzan, Rachel Novotny, John Kearney, Chloe P. Lozano

Research Outputs: 2025-Present

Background/Objectives: Coupling mobile health (mHealth) technology with community-based nutrition programs may enhance diet quality in adolescents. This pilot study evaluated the feasibility, acceptability, and preliminary efficacy of integrating PortionSize Ed (PSEd), an image-assisted dietary assessment and education app, into the six-week Hawaii Food and Lifeskills for Youth (HI-FLY) curriculum delivered via Supplemental Nutrition Assistance Program Education (SNAP-Ed). Methods: Adolescents (grades 6–8) from two classrooms were cluster-randomized into HI-FLY or HI-FLY + PSEd. Both groups received HI-FLY and completed Youth Questionnaires (YQ) and food records (written or app-based) at Weeks 0 and 7. Feasibility and acceptability were assessed via enrollment, attrition, …

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Factor Substitution Possibilities, Labor Share Dynamics, And Inequality In An Age Of Intangibles, Adnan Velic Jan 2025

Factor Substitution Possibilities, Labor Share Dynamics, And Inequality In An Age Of Intangibles, Adnan Velic

Articles

We examine the economy-wide degree of substitutability between intangible capital and other factor inputs in production using a large sample of advanced countries. In this context, we turn to studying the implications of intangible and tangible capital growth for labor income share dynamics. Compared to tangible capital, we find that intangible capital more strongly complements skilled labor. The analysis further indicates relative fungibility between tangible capital and a composite of intangible capital and skilled labor, in line with the rising prominence of knowledge-intensive tasks and AI-driven online platforms. The intrinsic nature of intangibles and their asymmetric effects across skilled and …

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Ceo Turnover And Shareholder Awareness In Cartel Cases, Catarina Marvão, Giancarlo Spagnolo Jan 2025

Ceo Turnover And Shareholder Awareness In Cartel Cases, Catarina Marvão, Giancarlo Spagnolo

Research Outputs: 2025-Present

We examine the consequences of cartel detection for the careers of CEOs in the US and the EU; the characteristics of colluding CEOs (e.g., tenure, age); and shareholders’ awareness of management misbehavior. Additionally, we examine at what level cartel decisions are made according to the available case documents. We find that only 4% of all CEOs in convicted EC cartel firms (1998-2020) are explicitly fired due to collusion, and that 30% of CEOs indicted in DOJ cartels (1985-2011) are fired. Often, CEOs remain in place or take on other high-level positions in the firm. This suggests that (most) shareholders are …

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Ontological Machines: Subjectivity And Relational Desire In Immersive And Interactive Environments, Toby Chanter Jan 2025

Ontological Machines: Subjectivity And Relational Desire In Immersive And Interactive Environments, Toby Chanter

School of Art, Design and Architecture Theses

This practice-based artistic research focuses on two contemporary spaces; namely the pedagogical spaces of healthcare Simulation Based Education (SBE), and the exhibition spaces of installation art. These seemingly unrelated activities share a range of technological and operational similarities that render their combined study under the banner of ‘immersive and interactive environments’ both novel and necessary. The lack of broad engagement with questions of representation, aesthetics, and affect is conspicuous in an educational practice that is reliant on, and implemented through, a network of overtly visual mediums, material technologies, and sensory modalities. In healthcare SBE, clinical skills are acquired, and medical …

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Un-Framing Transiting Trajectories: A ‘Beyond Disciplinary’ Approach To Curating In The Context Of Art And Science Discourse, Christina Ioanna Kazakou Jan 2025

Un-Framing Transiting Trajectories: A ‘Beyond Disciplinary’ Approach To Curating In The Context Of Art And Science Discourse, Christina Ioanna Kazakou

School of Art, Design and Architecture Theses

Abstract

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Facilitating Student Engagement In Elementary Science Classrooms With Reformed Teaching Principles, Nathaniel Bryant Jan 2025

Facilitating Student Engagement In Elementary Science Classrooms With Reformed Teaching Principles, Nathaniel Bryant

Dissertations and Theses @ UNI

Science performance among elementary school students in the United States has stagnated in recent years. To address this issue, the Next Generation Science Standards (NGSS) were introduced, advocating for a reform in science education. Traditionally, hands-on laboratory work has been used to help students understand scientific concepts through a "learn by doing" approach. However, students often become disengaged during practical work, as following a set procedure to replicate scientific phenomena does not reflect how scientists approach problems in their daily practice. It is now argued that hands-on laboratories should not only involve observation or manipulation of materials and equipment but …

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An Examination Of Middle School Girls’ Perceptions And Preferences Of Reading From A Device Versus Paper, Debra Kisch Jan 2025

An Examination Of Middle School Girls’ Perceptions And Preferences Of Reading From A Device Versus Paper, Debra Kisch

Dissertations and Theses @ UNI

Schools have been impacted by the technological advancements of the world. With these changes, students have been increasingly using technology, especially since the Covid-19 pandemic. The use of devices to read, both for pleasure and academically, have increased, especially since the introduction of Amazon’s Kindle in 2007 (Ashburn, 2024). Additionally, schools have started issuing devices for students to use and it is reported that forty-five percent of schools have a computer for each student (National Center for Education Statistics, 20). They found an extra 37% reported having a computer for each student in some grades or classrooms. States are also …

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Socioeconomic Status And Educational Opportunities Through The Eyes Of Students And Teachers: Diverse Realities, Shared Insights, Jill Schany Jan 2025

Socioeconomic Status And Educational Opportunities Through The Eyes Of Students And Teachers: Diverse Realities, Shared Insights, Jill Schany

Dissertations and Theses @ UNI

Sowl and Crain (2021) argue that despite recognizing the uniqueness of the place when it comes to rural demographics and needs, policies regarding education and the economy often prioritize urban areas, defining rural in opposition to urban without adequately addressing the specific needs of rural youth. Studies examining geographical disparities in educational outcomes traditionally concentrated on achievement gaps within urban and suburban areas, highlighting more startling gaps in cities with heightened racial, ethnic, and socioeconomic inequality and segregation. Literature also extensively discusses neighborhood effects on educational outcomes in densely populated regions, offering valuable insights into the distribution of educational opportunities …

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Application Of Gurney And Flight Of Fragment Calculations For Water Jet Velocities In Explosive Applications, Rachel L. Bauer, Tate B. Friedrich, Catherine E. Johnson Jan 2025

Application Of Gurney And Flight Of Fragment Calculations For Water Jet Velocities In Explosive Applications, Rachel L. Bauer, Tate B. Friedrich, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

This study investigates the application of Gurney and flight of fragment equations, typically used to predict metal fragment velocities, in modeling the water jet behavior. Three shotgun cartridge sizes were used as the energy source: 2.59 g, 5.83 g, and 7.13 g. Two configurations were tested: standard (full-barrel water load) and "negative 8" (partial water load). High-speed footage captured water column velocities, and Gurney models, including infinitely tamped and open-faced configurations, combined with the flight of fragment model were used to assess prediction accuracy. Results showed charge strength significantly affects water column velocity, with higher strengths yielding greater stability and …

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Understanding The Problem Of The Modern-Day Teacher Shortage: A Qualitative Phenomenological Study Of The Stories Of Teachers In The Profession, Adam R. Magliari Jan 2025

Understanding The Problem Of The Modern-Day Teacher Shortage: A Qualitative Phenomenological Study Of The Stories Of Teachers In The Profession, Adam R. Magliari

Dissertations and Theses @ UNI

The present study explored phenomenological research on teachers leaving the profession. This qualitative study examined the real-life experiences of teachers contemplating departure from the field of education. Additionally, it investigates how principals in schools with high retention rates support teachers in their craft, focusing on practices for retaining and recruiting during these challenging times. The researcher conducted interviews with four teachers and four principals using guiding questions, creating a case study for each participant. The collected artifacts were coded and thematically analyzed to address the three central questions of this research. Grounded in transformational leadership theory, this study examines its …

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Anxious, Persistent, And Resilient; Oh My!, Samantha Hilbert Jan 2025

Anxious, Persistent, And Resilient; Oh My!, Samantha Hilbert

Dissertations and Theses @ UNI

No abstract provided.

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Organization Communication Policy To Emphasize Student Employee Productivity, Yohan Fernando Jan 2025

Organization Communication Policy To Emphasize Student Employee Productivity, Yohan Fernando

Dissertations and Theses @ UNI

This study explored student perceptions of organizational communication policies and their impact on student employee productivity at a mid-sized Midwestern university. In-depth interviews with student employees revealed key themes—fairness, uniformity, openness, and communication—as essential elements of transparency. Additionally, academic work-life balance and scheduling flexibility emerged as critical factors in supporting productivity. The findings show that student employees view transparency and flexibility as central to both job satisfaction and productivity. Policies that promote equitable treatment and adaptable scheduling were especially influential. While organizational vision, mission, and values were recognized, they were not seen as major drivers of productivity. Similarly, rewards and …

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The Kinetics Of Shj Degradation: Time And Stressor Dependent Chemical Analysis And Simulation, Nicholas Moser-Mancewicz, Jorge Ochoa, Michael Martinez-Szewczyk, Thomas Bantle, Dana Kern, Dirk Jordan, Steve Johnston, Julia E. Medvedeva, Mariana Bertoni Jan 2025

The Kinetics Of Shj Degradation: Time And Stressor Dependent Chemical Analysis And Simulation, Nicholas Moser-Mancewicz, Jorge Ochoa, Michael Martinez-Szewczyk, Thomas Bantle, Dana Kern, Dirk Jordan, Steve Johnston, Julia E. Medvedeva, Mariana Bertoni

Physics Faculty Research & Creative Works

Despite record efficiencies, the wide adoption of silicon heterojunction is hampered by higher costs and uncertainties in long-term performance. Although recent publications report performance loss rates comparable to other field-deployed cSi technologies, the limited availability of field data and the dispersion in performance degradation results - particularly in open-circuit voltage - remain significant concerns. Various factors, including bulk and interfacial defects, charge carrier recombination dynamics, and environmental stressors such as temperature and humidity, contribute to this degradation. Understanding the mechanisms behind the open circuit voltage degradation as well as the kinetics involved is essential for developing mitigation strategies that enhance …

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Anisotropic Third-Harmonic Vortex Beam Generation With Ultrathin Germanium Arsenide Fork Gratings, Jayanta Deka, Jie Gao, Xiaodong Yang Jan 2025

Anisotropic Third-Harmonic Vortex Beam Generation With Ultrathin Germanium Arsenide Fork Gratings, Jayanta Deka, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Optical vortices have the tremendous potential to increase data capacity by leveraging the extra degree of freedom of orbital angular momentum. On the other hand, anisotropic 2D materials are promising building blocks for future integrated polarization-sensitive photonic and optoelectronic devices. Here, highly anisotropic third-harmonic optical vortex beam generation is demonstrated with fork holograms patterned on ultrathin 2D germanium arsenide flakes. It is shown that the anisotropic nonlinear vortex beam generation can be achieved independent of the fork grating orientation with respect to the crystallographic orientation. Furthermore, 2D fork hologram is designed to generate multiple optical vortices having different topological charges …

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High-Order Dynamic Mode Decomposition For Multidimensional Harmonic Retrieval, Yanming Zhang, Steven Gao, Lijun Jiang Jan 2025

High-Order Dynamic Mode Decomposition For Multidimensional Harmonic Retrieval, Yanming Zhang, Steven Gao, Lijun Jiang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Estimating channel parameters such as azimuth, elevation, Doppler shift, and delay is a key challenge in wireless communication, often formulated as a multidimensional harmonic retrieval (MHR) problem. To address this, we propose a high-order dynamic mode decomposition (HODMD) framework for robust frequency estimation from high-dimensional signals in noisy environments. The HODMD approach combines high-order singular value decomposition (HOSVD) to decompose tensor data into a core tensor and mode matrices, with dynamic mode decomposition (DMD) to extract frequencies from the imaginary parts of the DMD eigenvalues. Simulation examples validate the effectiveness of the proposed method, demonstrating its efficiency in solving MHR …

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Optimizing Uav Swarm Deployment For Efficient Communication Signal Strength Alignment In Disaster Scenarios, Mina Khalilzadeh Fathi, Chaoying Pei Jan 2025

Optimizing Uav Swarm Deployment For Efficient Communication Signal Strength Alignment In Disaster Scenarios, Mina Khalilzadeh Fathi, Chaoying Pei

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In disaster scenarios, establishing reliable communication infrastructure is critical, and unmanned aerial vehicle (UAV) swarms offer a promising solution as temporary base stations. This study models communication demand in disaster-affected areas by applying Gaussian kernels to building data, forming a spatial demand distribution. Signal strength is estimated using the normalized inverse Free Space Path Loss (FSPL) to account for realistic attenuation. To guide UAV placement, we extract high-demand regions from the demand distribution using a gradient-based thresholding method. Based on this information, we develop a greedy algorithm to iteratively position UAVs for optimal coverage in areas with the greatest communication …

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Aperiodically Intermittent Dynamic Event-Triggered Control For Predefined-Time Synchronization Of Stochastic Complex Networks, Lei Xue, Haoyu Zhou, Yongbao Wu, Jian Liu, Donald C. Wunsch Jan 2025

Aperiodically Intermittent Dynamic Event-Triggered Control For Predefined-Time Synchronization Of Stochastic Complex Networks, Lei Xue, Haoyu Zhou, Yongbao Wu, Jian Liu, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the problem of practical predefined-time synchronization in mean square (PTSMS) of stochastic complex networks (SCNs) is investigated through dynamic event-triggered control (E-TC). Different from the existing literature, this paper considers the dynamic E-TC in an a periodically intermittent control framework and employs the average control rate, which makes it easier to satisfy the conditions of the theorem. In comparison to existing finite-time and fixed-time synchronization, by introducing the time-varying function, it can be guaranteed that all states of SCNs achieve the practical PTSMS within a preset time without calculating the convergence time. Combined with stochastic analysis theory, …

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Discrimination Of Temperature And Strain By Characterizing Two Femtosecond Laser-Written Coincident Sapphire Fiber Bragg Gratings For Harsh Environment Applications, Farhan Mumtaz, Bohong Zhang, Koustav Dey, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang Jan 2025

Discrimination Of Temperature And Strain By Characterizing Two Femtosecond Laser-Written Coincident Sapphire Fiber Bragg Gratings For Harsh Environment Applications, Farhan Mumtaz, Bohong Zhang, Koustav Dey, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, two co-incident sapphire fiber Bragg gratings (SFBGs) were successfully inscribed utilizing a femtosecond (fs) laser to achieve a high fringe contrast interferogram. These two SFBGs employ a unique configuration, one parallel to the center axis, called p-SFBG, and the other forming an angle from the center-axis, called a-SFBG, allowing for simultaneous strain and temperature measurements with low crosstalk. As a proof of concept, p-SFBG and a-SFBG using line-by-line method are characterized, which are shorter in length (i.e., 1.5 mm), producing reflectivity of ~3dB. This effort demonstrates the use of two coincident SFBGs forming an angle of 2.29° …

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Adaptive Nussbaum Design For Nonholonomic Systems With Asymptotic Stabilization Against False Data Injection, Guilong Liu, Yongliang Yang, Weinan Gao, Donald C. Wunsch Jan 2025

Adaptive Nussbaum Design For Nonholonomic Systems With Asymptotic Stabilization Against False Data Injection, Guilong Liu, Yongliang Yang, Weinan Gao, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This article addresses the stabilization challenges of nonholonomic systems under the threat of false data injection (FDI) attacks, which compromise the integrity of state information. A novel adaptive control strategy using Nussbaum-type gains is proposed to ensure the asymptotic stability of the closed-loop system while maintaining signal boundedness. The approach extends conventional Nussbaum designs to handle multiple unknown control directions. It integrates online learning mechanisms to mitigate the impact of FDI attacks. Additionally, adaptive backstepping and fuzzy-logic systems are utilized to approximate and compensate for unknown nonlinear dynamics. The methodology transforms nonholonomic systems into equivalent cascade structures to address inherent …

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Safe Optimal Control Of Quadrotor Formations Using Multilayer Neural Networks And Continual Learning, Ehsan Soleimani, Irfan Ahmad Ganie, S. Jagannathan Jan 2025

Safe Optimal Control Of Quadrotor Formations Using Multilayer Neural Networks And Continual Learning, Ehsan Soleimani, Irfan Ahmad Ganie, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents an integral reinforcement learning-based optimal formation tracking scheme for multiple quadrotors unmanned aerial vehicles (QUAVs) experiencing nonlinear coupled dynamics and subject to constraints. We use multilayer neural networks (MNN) within an actor-critic framework where the MNN weights are tuned using singular value decomposition (SVD) of the activation function gradient to approximate optimal control policy via backstepping. Additionally, barrier Lyapunov functions (BLF) are introduced to ensure set invariance, thereby maintaining the quadrotors within a defined safety space due to constraints. A novel weight update law for each layer is derived using the HJB approximation error and control input …

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Prescribed-Time Nash Equilibrium Seeking For Pursuit-Evasion Game Under Intermittent Control With Undirected/Directed Graph, Lei Xue, Jianfeng Ye, Yongbao Wu, Jian Liu, D. C. Wunsch Jan 2025

Prescribed-Time Nash Equilibrium Seeking For Pursuit-Evasion Game Under Intermittent Control With Undirected/Directed Graph, Lei Xue, Jianfeng Ye, Yongbao Wu, Jian Liu, D. C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This paper studies the prescribed-time Nash equilibrium (PTNE) seeking problem of the pursuit-evasion game (PEG) with second-order dynamics under the intermittent control (IC) strategy. To achieve Nash equilibrium (NE) in a user-defined prescribed-time, a time-varying high-gain function is incorporated into the design. The core challenge lies in applying IC to NE seeking, which complicates the convergence analysis and control design. To address this sticking point, we construct an auxiliary function and propose a Lyapunov function considering second-order dynamics to solve the PTNE seeking problem of PEG. Building upon the results for undirected graphs, we further extend our findings to directed …

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Enhancing Measurement Accuracy In Industrial Applications: The Impact Of Sensor Data Imputation On Model Parameter Estimation, Steven Thompson, Michkath Omanda Bouraima, Maciej Jan Zawodniok Jan 2025

Enhancing Measurement Accuracy In Industrial Applications: The Impact Of Sensor Data Imputation On Model Parameter Estimation, Steven Thompson, Michkath Omanda Bouraima, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Digital twins are meant to revolutionize the manufacturing industry by enabling advanced condition monitoring and predictive maintenance processes. However, disruptions within the manufacturing process, such as sensor malfunctions or connectivity issues are inevitable and will cripple these advanced analysis methods if not properly addressed. Therefore, efficient data management and analysis practices are key to advancing this technology. This work examines the impact of missing data imputation on model parameter estimation, a crucial task in developing models for digital twins. We theoretically derive the Cramer-Rao Lower Bound (CRLB) for a DC signal with an unknown scalar parameter in the presence of …

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Distributed Sapphire Fiber Bragg Grating-Based Thermal Profiling Of Submerged Entry Nozzles, Farhan Mumtaz, Hanok W. Tekle, Bohong Zhang, Xiaodong Li, Sunday Abraham, Bryant Mathis, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang Jan 2025

Distributed Sapphire Fiber Bragg Grating-Based Thermal Profiling Of Submerged Entry Nozzles, Farhan Mumtaz, Hanok W. Tekle, Bohong Zhang, Xiaodong Li, Sunday Abraham, Bryant Mathis, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This article focuses on the application of sapphire fiber Bragg gratings (FBGs) for instrumentation in submerged entry nozzles (SENs) within the steelmaking industry. The SEN is pivotal for transferring molten steel from a tundish to a mold, while preventing the infiltration of oxygen and nitrogen from the surrounding environment. Maintaining optimal flow conditions in the mold is crucial for ensuring casting process stability and maintaining high-quality steel. Sapphire FBG sensors have been instrumented in SENs to enable distributed thermal mapping for monitoring the health of the SEN. The optical sensor comprises three cascaded sapphire FBGs inscribed using femtosecond (FS) laser …

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