Digital Commons Network^™

Enhancing Measurement Accuracy: The Impact Of Missing Data On Parameter Estimation In Mass-Spring-Damper Systems, Michkath Omanda Bouraima, Steven Thompson, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

In sensor-driven dynamic systems, missing data can severely degrade parameter estimation accuracy. This article investigates the impact of missing data on phase estimation in a mass-spring-damper system using an information-theoretic framework based on the Cramér-Rao Lower Bound (CRLB). Closed-form CRLB expressions are derived for four scenarios: complete data, missing completely at random (MCAR) deletion, MCAR-based imputation, and missing at random (MAR) missingness via a selection-weighted formulation. These bounds are used as theoretical benchmarks to evaluate classical imputation methods (last observation carried forward (LOCF), linear interpolation) and advanced approaches (Kalman filtering, Rauch-Tung-Striebel (RTS) smoothing, Bayesian inference, and transformer-based imputation) through Monte …

Rf-Attennet: A Hybrid Attention-Enhanced Network For Mixed Signal Classification In Uav Swarm Detection, Prajoy Podder, Mohammad Atikur Rahman, Maciej Zawodniok, Sanjay Madria

Electrical and Computer Engineering Faculty Research & Creative Works

The continuous increase of UAVs, particularly in swarms, creates significant challenges for security and airspace regulation. Traditional RF fingerprinting methods struggle to detect and classify UAV swarms due to overlapping signals and interference. This study introduces RF-AttenNet, a hybrid deep learning model designed to classify mixed UAV signals by analyzing composite RF spectrograms. RF-AttenNet uses dual attention mechanisms, channel and spatial attention to focus on critical spectral features, enabling the model to effectively separate and identify overlapping UAV signals. We have developed custom composite UAV datasets that simulate real-world swarm interference, incorporating both single and mixed UAV classes. RF-AttenNet achieves …

Fixed-Time Consensus Tracking For Nonlinear Multi-Agent Systems Under Aperiodically Intermittent Control, Lei Xue, Tong Wu, Wenwen Jia, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This article explores the problem of fixed-time consensus tracking (FT-CT) for nonlinear multi-agent systems utilizing the a periodically intermittent control (AIC) strategy. In contrast to existing control algorithms, the proposed algorithm utilizes the AIC strategy instead of the conventional continuous-time control strategy, effectively reducing the consumption of communication resources. Moreover, the problem of intermittent FT-CT is well handled by proposing the average control rate of the AIC strategy. Two theorems based on the cases of directed and undirected graphs are proposed, respectively. Finally, the validity of these results is confirmed through numerical simulations on a general nonlinear system and a …

Sapphire Optical Fiber Bragg Grating Sensors Based On Dispersive Microwave-Photonic Frequency-Time Domain Analysis, Ruimin Jie, Chen Zhu, Farhan Mumtaz, Koustav Dey, Bohong Zhang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Sapphire fiber Bragg gratings (SFBGs) have attracted growing interest for high temperature sensing in harsh environments, yet their interrogation typically relies on optical spectrum measurements, demanding a high-resolution optical spectrum analyzer (OSA) that is bulky, expensive, and constrained in acquisition speed. Moreover, the inherently multimode nature of sapphire fiber further complicates spectrum-based demodulation, thereby limiting the achievable sensing resolution. In this paper, we propose and experimentally demonstrate a microwave-photonic interrogation approach for SFBG sensors. Instead of measuring the optical reflection spectrum, the complex frequency response in the microwave domain of an SFBG is acquired using a vector network analyzer (VNA) …

Honey-Cnt Memristive Artificial Synaptic Device For Sustainable Neuromorphic Computing System, Md Mehedi Hasan Tanim, Zoe Templin, Harshvardhan Uppaluru, Jinhui Wang, Kuan Yew Cheong, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

Brain-inspired neuromorphic computing systems require hardware components analogous to biological neurons and synapses. Honey based natural organic memristor has demonstrated promising nonvolatile memristive behaviors, with the advantages of sustainability, environmentally friendliness, and low-cost manufacturing. In this study, carbon nanotubes (CNTs) are added in honey to fabricate honey-CNT memristive artificial synaptic devices. Honey-CNT film is characterized by micro-Raman spectroscopy and the distribution of CNT bundles embedded in the honey-CNT composite layer by cross-sectional scanning electron microscopy for the first time. Critical synaptic functions of the honey-CNT memristor, including spike-rate-dependent plasticity, spike voltage dependent plasticity, learn-forget-relearn, and supralinear spatial summation are revealed, …

Resolving Stiffness Trade-Offs In Simultaneous Pressure And Vibration Sensing Using A Corrugated-Tube Fiber-Optic Sensor, Yizheng Chen, Yan Tang, Jie Huang, Qi Zhang, Biyao Shi, Zewei Wu

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes and experimentally demonstrates a corrugated-tube-based fiber-optic sensor capable of measuring pressure, vibration, or both simultaneously. To address the limited sensitivity of conventional diaphragm-based designs, the sensor incorporates an optimized corrugated tube that balances the conflicting stiffness requirements for pressure and vibration measurements. The corrugated tube, acting as a mechanical transducer, is integrated with an extrinsic fiber-optic Fabry–Perot interferometer (EFPI). The EFPI cavity is formed between a reflective surface at the sealed end of the corrugated tube and the cleaved end face of an optical fiber fixed within a mounting assembly. In this configuration, displacement of the corrugated …

Nash Equilibrium Strategies For Multicluster Pursuit–Evasion Game With Disturbances: A Prescribed-Time Convergence Approach, Lei Xue, Xian Yu, Yongbao Wu, Jian Liu, Changyin Sun, D. C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This article investigates the problem of prescribed-time Nash equilibrium (NE) seeking for a multicluster pursuit–evasion game (PEG) subject to external disturbances. To mitigate the impact of disturbances and reach the NE within a user-defined prescribed time, a prescribed-time disturbance observer (PTDO) is devised to estimate and compensate for them. Based on this observation, a novel control algorithm is developed, which facilitates collaboration among multiple pursuers to capture multiple evaders within the prescribed time. It is theoretically demonstrated that the designed algorithm ensures prescribed-time convergence to the NE of the multicluster PEG with disturbances. Finally, numerical simulations are conducted to verify …

Corrections To: Enhancing Measurement Accuracy: The Impact Of Missing Data On Parameter Estimation In Mass-Spring-Damper Systems (Ieee Transactions On Instrumentation And Measurement (2026) 75 (1–12) Doi: 10.1109/Tim.2026.3676091), Michkath Omanda Bouraima, Steven Thompson, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

In the above article [1], a wording ambiguity appears in Proposition 4 regarding the description of the missing at random (MAR) mechanism. The published sentence states that the probability of observing the kth sample depends on the realized measurement value. This wording may be interpreted as dependence on the current unobserved value y[tk], which could suggest a missing not at random (MNAR) mechanism. The intended MAR mechanism is that the observation probability for the kth sample depends only on previously observed measurement information, such as y[tk-1], and not on the current unobserved value y[tk]. Therefore, the corrected wording clarifies that …

Event-Based Predefined-Time Synchronization For Complex Networks With Deception Attacks: An Asynchronously Intermittent Strategy, Lei Xue, Jiong Yu, Haoyu Zhou, Yongbao Wu, Jian Liu, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This article studies the practical predefined-time synchronization (PPTS) for complex networks (CNs) under deception attacks based on the asynchronously intermittent event-triggered control (AIE-TC). Notably, AIE-TC effectively integrates the advantages of asynchronously intermittent control (AIC) and event-triggered control, where AIC provides each subsystem node with independent control and rest intervals. Besides, all synchronization errors of the CNs converge to an adjustable neighborhood within the predefined time by designing a bounded time-varying function into the controller. Moreover, this article considers that the transmission network is subjected to stochastic deception attacks modeled by a Markov process, which captures the state-driven dynamic transition characteristics …

Greater Body Dissatisfaction At Admission Is Associated With Lower Bmi At Discharge In Anorexia Nervosa: Predictive Validity Of The Eating Pathology Symptoms Inventory., Danielle A N Chapa, Marianna L. Thomeczek, Brianne N. Richson, Alan Duffy, Kara A. Christensen Pacella, Kelsie T. Forbush, Renee D. Rienecke, Dan V. Blalock, Sara R. Gould, Victoria L. Perko, Philip S. Mehler

Manuscripts, Articles, Book Chapters and Other Papers

People with anorexia nervosa (AN) engage in dietary restriction and other weight loss behaviors that result in dangerously low body weight, leading to an increased risk for mortality and medical complications. Weight gain is one of the most important indicators of treatment progress and recovery for AN. There are limited predictors of weight gain for patients with AN, making it difficult for clinicians to anticipate which patients are likely to respond favorably to treatment. Thus, there is a need to identify additional, potentially modifiable predictors of weight gain within a higher level of care for AN. This study tested the …

Shedding Light On Cellular Glycolysis Pathway Kinetics: Combining Kinetic, Mechanistic Modelling Approaches With Label Free Microspectroscopic Imaging. (Spectralomics), Nitin Patil

Doctoral

Cellular metabolism and its intricate biochemical mechanisms which allow the conversion of nutrients into energy to sustain life are well understood, leading to numerous breakthroughs in science and technology, human health and wellbeing. From an industrial perspective the pathway kinetics are significant for monitoring cellular bioprocesses, screening desired metabolite phenotypes in drug discovery processes, etc.

An initial review of glycolysis pathway kinetics highlighted the lack of sophisticated approaches to monitor the metabolic pathway kinetics as a function of time in a non-destructive, non-invasive, label-free manner. Fluxomics, a metabolomics based approach providing high-throughput insights, can be considered a gold standard approach, …

Access To Digital Health Technologies: Personalized Framework And Global Perspectives, Sanjiv M Narayan, Mina K Chung, Demilade Adedinsewo, Luisa C C Brant, Leslie L Davis, David Duncker, Jennifer L Hall, Janet K Han, Carolyn S P Lam, Eldrin Lewis, Joseph Loscalzo, Manlio F Márquez, Vasiliki Rahimzadeh, Fatima Rodriguez, Prashanthan Sanders, Emma Svennberg, Kenneth Stein, Mintu Turakhia, Clyde Yancy, Antonis A Armoundas

Center for Medical Ethics and Health Policy Staff Publications

The emergence and rapid adoption of digital health technologies (DHT) present unprecedented opportunities to democratize and reduce disparities in health care by monitoring health and disease at the point of care in all patients. However, limited access to DHT is becoming a major obstacle to realizing these goals. Access to DHT is influenced not only by well-recognized social determinants of health, but also by digital determinants of health, such as digital literacy and the need for broad access to digital infrastructure, as well as commercial and economic factors. Addressing these challenges and designing unbiased systems of care are essential to …

Rapid Electrochemical Biosensor With Enhanced Accuracy And Repeatability Using Pyrene Nhs Ester Modified 3d Graphene Electrodes, S. Nazir, D. Jenkins, G. Pan

School of Engineering, Computing and Mathematics

A consistent and reproducible chemical modification of the transducer interface is essential to ensure effectiveimmobilization of bioreceptors, thereby improving the sensitivity and reproducibility of biosensors. Althoughnotable progress has been made in fabricating graphene-based biosensors, the effects of surface biofunctionalization on sensing performance remain not fully understood. This study shows that combining threedimensional (3D) graphene foam electrodes with a straightforward, single-step surface biofunctionalizationmethod is key to enhancing the performance of graphene-based biosensors. Specifically, it presents a single-stepapproach to functionalize the 3D graphene foam (Gii-Sens) with 1-pyrenebutyric acid N-hydroxysuccinimideester (Pyrene-NHS ester). Electrochemical techniques, including cyclic voltammetry (CV) and differential pulsevoltammetry (DPV), confirmed …

Performance Of Chatgpt-4, Gemini, And Deepseek-V3 On English-Translated Questions From The Taiwan National Dental Technician Licensing Examination Over A Three-Week Period, Yi-Pang Lee, Ching-Yi Huang, Andy Sun, Chun-Pin Chiang

Journal of Dental Sciences

Background/purpose: Large language models (LLMs) have shown potential in answering professional examination questions. This study evaluated the performance of ChatGPT-4, Gemini, and DeepSeek-V3 in answering English-translated questions from the 2023 Taiwan National Dental Technician Licensing Examination (TNDTLE) over a three-week period.

Materials and methods: A total of 194 English-translated, text-based multiple-choice questions were selected from the 2023 TNDTLE. ChatGPT-4, Gemini, and DeepSeek-V3 were used to answer the same set of English-translated questions at four time points: baseline and one-, two-, and three-week follow-ups. Accuracy rates (ARs) were calculated and compared to evaluate changes over time and differences among the three …

Performance Of Chatgpt-4, Gemini, And Deepseek-V3 In Answering The Prompt-Engineered Questions From The Taiwan National Dental Technician Licensing Examination Over A Three-Week Period, Yi-Pang Lee, Ching-Yi Huang, Andy Sun, Chun-Pin Chiang

Journal of Dental Sciences

Background/purpose: Large language models (LLMs) have shown promise in answering professional examination questions. This study evaluated the performance of ChatGPT-4, Gemini, and DeepSeek-V3 in answering prompt-engineered questions selected from the 2023 Taiwan National Dental Technician Licensing Examination (TNDTLE) over a three-week period.

Materials and methods: A total of 194 Chinese-language text-based multiple-choice questions were selected from the 2023 TNDTLE. The three LLMs answered these questions using a standardized prompt referring to 17 dental technology textbooks. Accuracy rates (ARs) were recorded at baseline and after one, two, and three weeks. Comparisons of ARs over time, among three LLMs, between basic and …

Ensemble Learning For Predicting Periapical Lesions From Dental Radiographs, Fang-Yuan Liao, Ming-Jyun Jian, Abdullah Sarini, Yulianto Jesica, Yen-Kun Lin, Hsun-Yu Huang

Journal of Dental Sciences

Background/purpose: Diagnosing periapical cysts and granulomas using periapical radiographs is challenging due to subtle radiographic differences. This study aimed to develop a machine learning–based diagnostic framework to improve lesion classification through ensemble learning and dentin standardization.

Materials and methods: Five models—Support Vector Classifier (SVC), Nu-SVC, K-Nearest Neighbors (KNN) and Decision Tree—were trained on 144 pre-treatment periapical radiographs (70 cysts and 74 granulomas). Dentin standardization normalized grayscale values to ensure feature consistency. A weighted soft voting strategy was employed to integrate predictions, with model weights derived from individual diagnostic performance. Model performance was evaluated via five-fold cross-validation. Statistical significance among models …

Development Of A Risk Scoring System For Predicting Post-Extraction Medication-Related Osteonecrosis Of Jaws: A Derivation And Validation Cohort Study, Ling-Ying Wei, Ching-Ming Chiu, Sang-Heng Kok, Hung-Ying Lin, Wei-Yih Chiu, Hao-Hong Chang, Shih-Jung Cheng, Jang-Jaer Lee

Journal of Dental Sciences

Background/purpose: Although risk factors for medication-related osteonecrosis of the jaw (MRONJ) are known, clinical assessment prior to dental extraction remains largely subjective. We aimed to develop and externally validate a simple clinical risk scoring system to predict post-extraction MRONJ in osteoporotic patients receiving antiresorptive therapy (ART) and support evidence-based clinical decision-making.

Materials and methods: This retrospective cohort study used a derivation cohort (N = 1,067 extractions, 2003‒2022) to develop a 5- to 16-point risk score system based on five predictors (age ≥ 75, ART duration ≥ 24 months, bisphosphonate use, drug interruption < 3 months, and extraction site). The model was validated in an independent cohort (N = 928 extractions, 2022–2024) using a pre-defined ≥12 cut-off. Performance metrics included the area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results: MRONJ prevalence was lower in the validation …

Influence Of All-On-4 Implant Angles On Stability And Crestal Bone - A Finite Element Optimization Analysis,, Jing-Jie Chen, Chen-Sheng Chen

Journal of Dental Sciences

No abstract provided.

Mesenchymal Stem Cells Derived From Gingiva Normoxic Or Hypoxic-Preconditioning Allogenous Transplantation Affect Orthodontic Tooth Movement In Vivo, Alexander Patera Nugraha, Guang Hong

Journal of Dental Sciences

No abstract provided.

Accuracy Of Full-Arch Implant Scans Using Different Horizontal Scan Bodies In An Angulated Model: An In Vitro Study, Tsung-Yu Lin, Tong-Mei Wang, Li-Deh Lin

Journal of Dental Sciences

Background/purpose: Various newly developed horizontal implant scan bodies have been introduced to enhance full-arch scan accuracy. However, their performance in angulated implant scenarios remains unclear. The purpose of this study was to evaluate the accuracy of four specific horizontal scan body systems.

Materials and methods: A stone cast containing six implant abutment analogs served as the master model. Four horizontal scan body systems (ArcB GeoMEDI, Apollo Smartflag, Scan Ladder, and ioConnect) were evaluated. Ten scans were performed per group using an intraoral scanner (Medit i900c). The mean surface deviation, root mean square (RMS) values against the reference files, and the …

A Bibliometric Evolution Of Molecular Mechanisms And Emerging Research Trends Of Therapeutic Resistance In Oral Cancer, Chu-Yen Chien, Ying-Chen Chen, Jia-Rong Wu, Hsu-Hua Chu, Yi-Jen Hung, Yi-Shing Shieh

Journal of Dental Sciences

Background/purpose: Drug resistance has served as a primary determinant of treatment failure and disease recurrence in oral cancer. The present study aimed to evaluate the global research landscape of drug resistance mechanisms in oral cancer by integrating bibliometric mapping with bioinformatic validation.

Materials and methods: A comprehensive dataset of 1660 publications was retrieved from the Scopus database. Bibliometric analyses were performed using Biblioshiny and VOSviewer to evaluate publication trends, collaborative networks, and thematic evolution. To bridge research trends with biological mechanisms, 1469 genes associated with oral cancer and drug resistance were extracted from the GeneCards database and subjected to functional …

Corrigendum To "Human Umbilical Cord Mesenchymal Stem Cells Secretome And Nanoemulsion Propolis Combination Ameliorate Osteoclastogenesis In Lipopolysaccharide-Induced Osteolysis In Hyperglycemia Rats"

Journal of Dental Sciences

No abstract provided.

Study Of Fire Regimes In Southwestern Australia Using Geospatial Techniques, Ana Do Carmo Carvalho

Theses: Doctorates and Masters

The Northern Jarrah Forest in Southwestern Australia (SWA), part of a global biodiversity hotspot, is home to fire-sensitive tree species such as marri (Corymbia calophylla) and jarrah (Eucalyptus marginata). As climate change intensifies drought and extreme fire events, understanding the drivers of fire severity is increasingly critical. This thesis analyses fire regimes within the Mundaring drinking water catchment to better understand the spatiotemporal complexity of fire severity in relation to fire history and environmental factors.

The thesis commences with a review of three Fire History Databases (FHDs) used in SWA, highlighting significant inconsistencies and data gaps across time and space. …

An Investigation Into The Mechanisms, Barriers, Degree And Sphere Of Risk Influence In Corporate Security, Nicola Lockhart

Theses: Doctorates and Masters

This study investigates the sphere of corporate security risk influence within organisations, addressing the conceptual and practical ambiguity surrounding the activity’s capacity to shape organisational decisions, behaviours, and risk priorities. While corporate security’s protective role is widely recognised, its broader organisational risk influence remains under-theorised. The study defines the sphere of risk influence as the range of organisational stakeholders and environments with which the corporate security activity interacts, and within which it may engage, persuade, and mobilise action. This sphere is analytically constituted through the intersection of three dimensions: the mechanisms through which influence is attempted, the barriers that constrain …

Development Of Virtual Reality Learning Environments In Science To Engage Secondary Students In Hazardous Activities, Luke Spartalis

Theses: Doctorates and Masters

This research examines the need for change in including hazardous activities in education. As different learning technologies develop, platforms that retain authentic outcomes via virtual reality are needed. The main objective of this research is to examine the inclusion of Virtual Reality Learning Environments (VRLEs) to determine their value in areas that include hazardous conditions. The research considered the ways that VR tools could be optimised to support these activities, as well as considering the challenges of VRLE implementation. The study examined whether VRLE’s allowed for authentic experiences to sufficiently drive an acceptance of VR to complement existing teaching and …

Understanding Climate Change And Wellbeing Through Bhutan's Pursuit Of Gross National Happiness, Tashi Dorji

Theses: Doctorates and Masters

Climate change has evolved into one of the biggest global challenges of the twenty first century reshaping ecological systems and social conditions with wide-ranging implications for human wellbeing. Bhutan offers a distinct context to explore interactions between climate change and wellbeing as it remains guided by its wellbeing-centred development philosophy of Gross National Happiness (GNH). At the same time, it remains highly vulnerable to climate change despite being the only carbon negative country in the world. Nonetheless, the intersections between climate change and GNH have not been systematically explored.

This research aims to explore the relationship between climate change and …

Development And Evaluation Of A Gc-Msms Method For The Quantification Of Gamma Hydroxybutyrate In Hair, Jacob Robert Keller

Theses: Doctorates and Masters

Gamma (γ)-hydroxybutyrate (GHB) is an endogenous short-chain fatty acid, and is of forensic importance due to its use in drug facilitated sexual assault (DFSA). Exogenous GHB has a limited window of detection in blood (1-hour) and urine (12-hours). Testing hair allows detection of drugs months after ingestion. This thesis contains a literature review which compares published methods which determine concentration of endogenous GHB in hair to determine which procedures are suitable for experimental comparison. The aims of this thesis were to develop a GC-MS-based method for the detection of GHB, test various methods to improve extraction, determine linearity, precision, accuracy, …

Play-Based Learning In Private International Preschools In Cairo: Teachers' Perspectives, Kesha L. Stovall

Theses and Dissertations

This thesis explores how play-based learning is practiced and contextualized in private, international preschools in Cairo, Egypt through the perspective of teachers. It calls upon both historical and contemporary theories of play and play pedagogies ranging from the times of Plato and Al-Farabi to the 21st century with Montessori and Dewey. Using a contemporary theory of play presented by Stuart Lester and Wendy Russell as a guiding framework, it examines how play and play-based learning are implemented, shaped and even challenged in a Cairene context. These contexts include sociocultural factors such as parents’ expectations and aspirations, institutional barriers, teacher development …

Load-Settlement Behaviour Of Tailings Dam Foundation Strengthened Using The Wraparound Geosynthetic Reinforcement Technique, Francis Otieno, Sanjay Kumar Shukla

Research outputs 2022 to 2026

This paper presents a numerical investigation of the load–settlement behaviour of a geosynthetic-reinforced tailings foundation comprised of gold tailings, subjected to the weight of a tailings dam embankment. The study considered varying conditions, including the horizontal and vertical components of the wraparound reinforcement, reinforcement burial depth, and shear strength parameters of the foundation material. A particular focus of this study is to investigate the effect of reinforcement wraparound ends on the settlement behaviour of the foundation using commercially available finite element (FE) software. The reinforcement is a single-layer biaxial woven geotextile, with and without wraparound ends, at varying depths from …

Measuring Teachers’ Beliefs In Their Capacity To Use Differentiated Instruction In Their Classrooms: Development, Validation And Confirmation Of A Self-Efficacy Scale, Kathryn Gibbs, Stuart Woodcock, Nicole Dargue, Leah Le, Eunjae Park, Tom Porter, Gemma Scarparolo

Research outputs 2022 to 2026

The purpose of this study was to develop, validate and confirm a scale to gain a better understanding of teachers’ beliefs in their capacity to use differentiated instruction in their classrooms. Differentiation is an effective approach to teaching, designed to enable equitable learning opportunities for every student. Teachers are recommended to differentiate aspects of teaching, instruction, learning, assessment and the learning environment due to the increasing student heterogeneity within classrooms worldwide. Emerging literature has suggested that teacher self-efficacy may influence how teachers use this teaching approach. It is unknown if there is an existing scale that measures teachers’ self-efficacy when …