Digital Commons Network^™

Cognitive Load Classification Using Functional Near-Infrared Spectroscopy, Pratham Shah

Theses and Dissertations (Comprehensive)

This thesis investigates the classification of cognitive load using functional near-infrared spectroscopy (fNIRS) signals recorded during an N-back working memory task. The study introduces a novel short-channel correction layer designed to suppress superficial physiological noise adaptively, addressing limitations of traditional General Linear Model (GLM) based regression. A single participant dataset comprising 69 validated sessions was analyzed using both conventional machine learning and deep learning approaches. Traditional classifiers: Linear Discriminant Analysis (LDA), Support Vector Machines (SVM), Random Forests, and Gradient Boosting were first evaluated using statistical features (mean, variance, peak, and slope). Among these, Gradient Boosting achieved the highest accuracy (55.6%), …

" Who Am I Here?" Exploring The Racial Identity Development Of Chinese Adolescent International Students In Canada: A Constructivist Grounded Theory Approach, Wen Juan Song

Theses and Dissertations (Comprehensive)

Abstract

This dissertation explores the racial identity development and associated mental health challenges of Chinese Adolescent International Students (CAIS) in Canada, a population navigating complex intersections of race, age, migration, and belonging. Despite their growing presence in Canadian secondary education, CAIS remain understudied in both educational and mental health research, particularly in relation to racial identity development within Western, multicultural societies. Using a Constructivist Grounded Theory methodology, this study draws on in-depth interviews with twenty-five CAIS participants, including ten current high school students, three returnees to China, and twelve who remained abroad in post-secondary education or employment.  The study is …

Unveiling Othering Experiences In Multiethnic Families: Narratives Of Identity And Belonging Among White/Hispanoamerican Women, Maria-Esther Wood

Theses and Dissertations (Comprehensive)

This dissertation explores the lived experiences of multiethnic Hispanoamerican women as they navigate identity, belonging, and familial othering within the context of multiethnic family systems. Using qualitative narrative inquiry, the study centres the voices of nine women residing in Ontario, each with one white parent and one Hispanoamerican parent, ranging in age from 19 to 65. Guided by Dewey’s three-dimensional model of narrative analysis, the research explores how personal stories reflect broader patterns of othering and belonging, the central research question asks: What specific forms of othering related to identity and belonging—inclusive of discrimination and racist treatment—do multiethnic Hispanoamerican women …

The Forgotten Carers: A Study Of The Lived Experiences Of Chinese Canadians Caring For A Family Member With Borderline Personality Disorder (Bpd/Fbpd), Judy Y.F. Wu

Theses and Dissertations (Comprehensive)

There is a fair amount of literature on Borderline Personality Disorder (BPD); however, it still lags behind research on other major mental illnesses such as depression and schizophrenia (Furnham et al., 2015). Similarly, while there has been ample research on caring from various perspectives; little has been explored regarding caring for individuals with BPD. Research on Chinese Canadian families caring for patients with BPD is even more scarce. This study explored the lived experiences of Chinese Canadians caring for family members diagnosed with BPD (FBPD) in the Greater Toronto Area (GTA), Ontario, Canada. BPD is characterised by “interpersonal hypersensitivity, affective …

Error-Driven Density Control For Compact Gaussian Splatting Under Sparse Supervision, Abdelrhman Elrawy

Theses and Dissertations (Comprehensive)

This thesis studies efficiency and stability challenges in Gaussian-splatting-based reconstruction under sparse supervision. In few-shot novel view synthesis, standard 3D Gaussian Splatting (3DGS) can overfit the limited training views and grow an unnecessarily large number of primitives due to limitations in its Adaptive Density Control (ADC) mechanism. This thesis introduces an error-driven reformulation of ADC that triggers densification using opacity gradients as a lightweight proxy for rendering error, and shows that such aggressive densification must be paired with delayed and conservative pruning to prevent destructive create--destroy cycles. When combined with depth-based geometric regularization, the resulting framework produces substantially more compact …

Robust And Interpretable Medical Image Segmentation Via Retrieval And Mechanistic Analysis, Salma Ahmed

Theses and Dissertations (Comprehensive)

Medical image segmentation is a critical component of clinical decision-making, yet deep learning based segmentation models face persistent challenges. These models typically require large volumes of densely annotated data, exhibit strong sensitivity to domain shifts across scanners and patient populations, and lack explicit anatomical priors. Furthermore, despite continual architectural advances beyond fully convolutional networks, most segmentation models remain opaque, where they lack the granularity required for component-level analysis. As a result, when segmentation models fail, it is difficult to identify which internal representations are responsible, limiting developers’ ability to diagnose errors, improve robustness, or establish trust in clinical settings. Existing …

Taylorkan-Vit: Parameter-Efficient Vision Transformers For Medical Image Classification, Kaniz Fatema, Dr. Emad Mohammed, Dr. Sukhjit Singh Sehra

Theses and Dissertations (Comprehensive)

Effective and interpretable classification of medical images remains a critical challenge in computer-aided diagnosis, particularly in data-scarce and resource-constrained clinical settings where traditional deep learning models prove impractical. This study addresses the fundamental barrier to Vision Transformer adoption in medical imaging—massive parameter counts and data requirements—through a systematic two-phase methodology. Phase 1 evaluates three spline-based Kolmogorov–Arnold Network (KAN) variants to identify the optimal nonlinear approximation function for parameter-efficient medical image classification: SBTAYLOR-KAN (B-splines with Taylor series), SBRBF-KAN (B-splines with Radial Basis Functions), and SBWAVELET-KAN (B-splines with Morlet wavelets). Comprehensive experiments across brain MRI, chest X-rays, and tuberculosis datasets—without any image …

Three Essays On Corporate Bond Short Selling, Climate And Credit Risks, Manisha Thapa

Theses and Dissertations (Comprehensive)

This dissertation comprises three essays investigating topics on Corporate Bond Short Selling, Climate and Credit Risks.

The first essay addresses the question: Does climate risk influence bond short selling? We address this question by studying how climate risk influences the relationship between corporate bond short selling and subsequent credit default swap (CDS) spreads. We find that future CDS spreads are strongly related to bond short selling for the high climate risk firms. In particular, our fixed effects triple difference-in-differences (DiD) regressions show that sensitivity of subsequent CDS spreads to lagged bond short selling is significantly higher for firms with high …

Investigating The Immunostimulatory Potential Of Dsrna-Silk Nanoparticle Complexes In Melanoma, Samuel J. Peters

Theses and Dissertations (Comprehensive)

The rate of resistance to immune checkpoint inhibitor treatment in metastatic melanoma is quite high, with an overall rate of 70%. Melanoma achieves these high rates of resistance by suppressing the immune response in the tumour microenvironment (TME), making them immunologically “cold”. The type 1 interferon response could be leveraged to initiate immune responses in melanoma, making their “cold” TMEs “warm” again. Double-stranded ribonucleic acids (dsRNAs) are potent activators of an innate immune response; however, they are susceptible to degradation by nucleases present in the body and need a carrier. Silk nanoparticles (SNPs) are an ideal drug-delivery platform as they …

“My Voice Is Trauma, My Voice Is Healing:” A Feminist, Trauma-Informed Embodied Study On The Impact Of Gender-Based Violence In Classical Music Communities, Sarah Pearson

Theses and Dissertations (Comprehensive)

This Social Work doctoral dissertation explores the impact of gender-based violence (GBV) in classical music communities on survivor-artists. This is an intersectional feminist, trauma-informed, embodied study that draws on these three theoretical concepts to conceive of classical music as an institution of both colonial patriarchal power and a site of spirituality and meaning-making. The issue of systemic GBV in the performing arts has been a focus of headline news and sensational celebrity stories in the last decade following the MeToo hashtag and is slowly gaining some attention in academic research.

For this qualitative study, the sample consisted of 14 participants …

Impacts Of Burn Severity On The Hydro-Physical, Chemical And Thermal Properties Of Sub-Arctic Peat, Joshua B. Meyer Mr

Theses and Dissertations (Comprehensive)

Under current climate change, summer season in the boreal regions of Canada is becoming increasingly warmer and drier. This shift is driving increases in the frequency and intensity of naturally occurring wildfires and allowing access to areas not normally susceptible to fire such as wetlands. In peatland areas, these increasingly large fires can create complex burn scars, which contain a wide variety of different burn severities across different landcover types. This variety calls for a greater understanding of how varying fire intensity affects the hydro physical, chemical, and thermal characteristics of boreal peat. This study aims to deepen that understanding …

Exploring Religious-Spiritual Struggles Among Muslim Immigrants In The Canadian Context, Ayse Erenay

Theses and Dissertations (Comprehensive)

Migration to a new culture and adaptation to a different lifestyle may cause emotional and psychological stress. In some cases, immigrants may experience religious and/or spiritual (R/S) struggles due to challenges to their beliefs and practices in the country they have immigrated to. Based on Pargament (2007, 2013)’s R/S struggle framework, these struggles may include questions about the ultimate meaning of life, one’s relationship with God, or doubt about one’s belonging within a religious or spiritual community. Muslim immigrants face unique struggles since Islamic teachings require Muslims to visibly practice their faith and reflect on God’s presence as a central …

Sex Differences In The Use Of Cognitive Strategies In Brown-Headed Cowbirds (Molothrus Ater), Nicole E. Robinson Ms.

Theses and Dissertations (Comprehensive)

Cognition is widely believed to be adaptive, yet few studies directly show that variation in cognitive performance is related to fitness. Brown-headed cowbirds (Molothrus ater) provide a powerful system for addressing this gap because brood parasitism creates strikingly different reproductive problems for females and males. Females face the spatial demands of nest-prospecting, whereas males face social and competitive demands associated with access to mates. Across five experiments, cowbirds were tested on an outdoor foraging task designed as an analogue of nest prospecting, with manipulations of retention interval, cue conflict, and breeding condition, followed by observations of reproductive behaviour. …

The Power Of Letting Go: The Role Of Goal Adjustment Capacities Across Future And Daily Perspectives Of Chronic Illness, Alexandra Dagher, Meaghan Barlow

Theses and Dissertations (Comprehensive)

Goal adjustment capacities are self-regulatory processes that protect psychological well-being by allowing individuals to disengage from unattainable goals and reengage in new attainable ones. Although research has shown that these capacities are beneficial in the context of chronic illness, little is known about how their effectiveness may differ across various aspects of the chronic illness experience. The present research consisted of two distinct yet complementary studies examining the role of goal adjustment capacities in two chronic illness contexts. Study 1 (N = 149) prompted participants to imagine the future progression of a chronic illness, whereas Study 2 (N …

Permafrost Microtopography And Active Layer Hydrology In The Western Canadian Arctic, Tobias L. Leonhard

Theses and Dissertations (Comprehensive)

The growing interest in Arctic regions will likely increase the use of nuclear energy in the Arctic. While this energy source has a high potential to improve economic opportunities in the Arctic, it also increases the release of radioactive material (radionuclides). Radionuclides are already found in the Arctic and are traced back to natural as well as anthropogenic sources. Water is one of the dominant transport vectors for solutes such as radionuclides or other contaminants. Therefore, improving our understanding of Arctic hydrology is important for assessing future environmental risks such as the release of radionuclides. Topographic and microtopographic features are …

Fear Across The Map: A Cross-Municipal Analysis Of Fear Of Crime In Canada, Muhammad Ali

Theses and Dissertations (Comprehensive)

This study examines the predictors of fear of crime (FOC) across three Canadian municipalities: Hamilton, Ontario; Brantford, Ontario; and North Battleford, Saskatchewan. Data from 1,956 survey responses were analyzed to understand how certain factors shape FOC across different municipal contexts in Canada. This study uses descriptive statistics, reliability analyses, correlation matrices, and Ordinary Least Squares regression models to examine whether FOC, and the predictors of FOC, operate consistently across municipalities. The findings indicate that the predictors of FOC are relatively reliable across municipal contexts. However, the influence of the predictors of FOC can vary across municipalities. Importantly, the level of …

Timing, Targets, And Teaching: How Employee Help-Seeking Influences Downward Knowledge Sharing, Nicholle E. Kovach

Theses and Dissertations (Comprehensive)

Knowledge sharing between managers and employees is critical for employee development and organizational performance. However, managers differ in whether they share knowledge, and in the type of knowledge shared. While solution-oriented knowledge offers immediate answers to improve short-term performance, process-oriented knowledge promotes long-term learning and employee development. The purpose of my dissertation is to investigate factors that influence managers’ knowledge-sharing decisions.

I conduct two studies to investigate my predictions. In Study 1, I examine how the timing of employee help-seeking requests, the source of performance targets and employee historical performance influence the type and quality of managers’ knowledge-sharing responses. Drawing …

The Impact Of Synchronous And Asynchronous Preference On The Performance Of Distance Learning Students, Christopher A. Wilson

Electronic Theses and Dissertations

Distance learning is a growing part of education. The transition to distance learning was underway at higher education institutions, but the COVID-19 pandemic forced institutions of all types to rapidly transition to distance learning. The technology that was adapted during this emergency distance learning remained in the classroom once normal instruction resumed. This quantitative study examined two aspects of distance learning technology in education. The study examined student preference for either synchronous or asynchronous instruction through the framework of expectancy theory. Students who were more familiar with the course material were hypothesized to have a higher expectation of success and …

Strong Q-Analogues For Values Of The Dirichlet Beta Function, Ankush Goswami, Tim Huber

School of Mathematical & Statistical Sciences Faculty Publications

An infinite class of relations between modular forms is constructed that generalizes evaluations of the Dirichlet beta function at odd positive integers. The work is motivated by a base case appearing in Ramanujan’s Notebooks and a parallel construction for the Riemann zeta function. The identities are shown to be strong q-analogues by virtue of their reduction to the classical beta evaluations as 𝑞→1− and explicit evaluations at CM points for |𝑞|< 1. We also determine asymptotic formulas for the Fourier coefficients of the associated modular forms.

Optimal Quantization On Spherical Surfaces: Continuous And Discrete Models—A Beginner-Friendly Expository Study, Mrinal Kanti Roychowdhury

School of Mathematical & Statistical Sciences Faculty Publications

This expository paper provides a unified and pedagogical introduction to optimal quantization for probability measures supported on spherical curves and discrete subsets ofthe sphere, emphasizing both continuous and discrete settings. We first present a detailedgeometric and analytical foundation for intrinsic quantization on the unit sphere, includingdefinitions of great and small circles, spherical triangles, geodesic distance, Slerp interpolation,the Fréchet mean, spherical Voronoi regions, centroid conditions, and quantizationdimensions. Building upon this framework, we develop explicit continuous and discretequantization models on spherical curves, namely great circles, small circles, and greatcircular arcs—supported by rigorous derivations and pedagogical exposition. For uniformcontinuous distributions, we compute optimal …

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) …

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 …

Lidar-Based Framework For Detecting Suspicious Human Activities, Ahd Aljumah, Charalampos Antoniadis, Hakim Ghazzai, Nawfal Guefrachi, Ahmad Alsharoa, Gianluca Setti

Electrical and Computer Engineering Faculty Research & Creative Works

This study explores the development of Human Activity Recognition (HAR) systems capable of identifying suspicious activities to enhance security in public spaces. We propose an innovative solution that integrates LiDAR sensors with deep learning technologies. Our method employs advanced models operating on LiDAR point cloud, PV-RCNN for human detection, and LidarGait++ for classifying activities into categories such as standing or walking (non-suspicious) and sneaking or fighting (suspicious). Due to the scarcity of suitable real-world datasets for training such systems, we utilize a 3D simulation tool, Blender, to create realistic environments and generate labeled point cloud data. This synthetic dataset allows …

Deep Learning Approach For Microwave Imaging Based On Deep Convolutional Asymmetric Encoder-Decoder Structure And Physics-Induced Loss, He Ming Yao, Shiji Song, Michael Kwok Po Ng, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we introduce an innovative deep learning (DL) methodology designed for real-time quantitative microwave imaging (MWI). Our approach is centered around the utilization of a deep convolutional asymmetric encoder-decoder structure (DCAEDS), which requires only a single-frequency far-field measurement of the electromagnetic (EM) scattered field as input and subsequently predicts the contrasts (permittivities) of the target materials. During the offline training process, we incorporate an EM forward solver specifically crafted to compute the EM scattered field generated by the predicted target contrasts (permittivities) produced by the DCAEDS. The DCAEDS is seamlessly integrated with this EM forward solver to optimize …

Femtosecond-Laser-Inscribed Cladding Fiber Bragg Gratings: Architectures, Design Trade-Offs And Future Sensing Opportunities, Koustav Dey, Rex E. Gerald, Chen Zhu, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Femtosecond (fs) laser inscription enables fiber Bragg gratings (FBGs) to be positioned beyond the fiber core, including within the cladding, thereby expanding control over modal interactions and directional sensing. These cladding fiber Bragg gratings (CLFBGs) extend FBG functionality through interactions with core, cladding, and evanescent fields. Their operation does not involve fundamentally different grating physics; rather, core-mode, cladding-mode, and coupled-mode responses depend on power distribution, modal overlap with the laser-inscribed refractive-index modulation (RIM), grating position, fiber geometry, modal excitation, and interrogation configuration. This Perspective reviews advances in CLFBG fabrication, optical characteristics, sensing mechanisms, and applications. Cladding-waveguide-assisted, evanescent-field-coupled, and direct cladding-mode-excitation …

Gauge-Invariant Gravitational Wave Polarization In Metric F(R) Gravity With Cosmological Implications, Ramesh Radhakrishnan, David Mcnutt, Delaram Mirfendereski, Alejandro Pinero, Eric Davis, William Julius, Gerald Cleaver

Physics & Astronomy Faculty Publications

We develop a fully gauge-invariant analysis of gravitational-wave polarizations in metric 𝑓⁡(𝑅) gravity with a particular focus on the modified Starobinsky model 𝑓⁡(𝑅) =𝑅 +𝛼⁢𝑅2 −2⁢Λ, whose constant-curvature solution 𝑅𝑑 =4⁢Λ provides a natural de Sitter background for both early- and late-time cosmology. Linearizing the field equations around this background, we derive the Klein–Gordon equation for the curvature perturbation 𝛿⁢𝑅 and show that the scalar propagating mode acquires a mass 𝑚2𝜓 =1/(6⁢𝛼), highlighting how the same scalar degree of freedom governs inflationary dynamics at high curvature and the propagation of gravitational waves in the current accelerating Universe. Using the scalar–vector–tensor …

Gpu And Pso Accelerated Low-Latency Fully-Coherent All-Sky Search For Compact Binary Coalescences, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

The fully-coherent all-sky (FCAS) search, which combines data from a gravitational wave detector network into a single likelihood function, is the preferred method prescribed by statistical theory for Gaussian noise. However, so far, its exorbitant computational cost has blocked its use for compact binary coalescence searches. We introduce a solution combining Particle Swarm Optimization with Graphics Processing Unit (GPU) acceleration that is ≈ 50-fold faster than real-time analysis. This transforms the prospect of a low-latency FCAS search on all GW data into a practical reality for the first time. With large-scale simulations enabled by this speedup, we examine the issue …

Efficient Search For Detection Candidates Using A Peak Finder Strategy For All-Sky-All-Frequency Gravitational Wave Radiometer, Arindam Sharma, Deepali Agarwal, Sanjit Mitra

Physics & Astronomy Faculty Publications

The first all-sky-all-frequency (ASAF) radiometer search was conducted using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. The significance of this search lies in its fast and unmodeled approach, leveraging a cross-correlation technique to identify common signals across the detector network. As a result, this method serves as an excellent alternative to search for unknown or poorly modeled continuous wave sources and narrow band components of the gravitational wave (GW) background. For continuous wave sources whose waveform can be modeled, this method can serve as the first stage of a hierarchical scheme by …

Pediatric Both Bone Fracture Leading To Median Nerve Entrapment: A Case Report, Joshua Lyndon Dale, Frank Gerold

School of Medicine Publications

Introduction: Both-bone forearm fractures are common in pediatric patients and most often result from a fall onto an outstretched hand. Although rare, nerve entrapments, particularly of the median nerve, can occur, especially following closed reduction.

Case report: We present the case of a 13-year-old male who sustained a both-bone forearm fracture while on vacation in Mexico. The injury was managed with closed reduction and casting. Despite appropriate treatment, the patient developed progressive numbness, tingling, and thenar atrophy in the median nerve distribution. Electromyography and nerve conduction studies confirmed significant median nerve dysfunction. Surgical exploration revealed the median nerve entrapped in …

"Just Let Your Soul Glo": Humorous Music In Black American Comedy Films, Drew Brady

Music Theses and Dissertations

In this thesis, I inspect ways in which music has been used to create humor and meaning in black American cinema. In doing so, I address gaps in film music scholarship, as music in comedy films and in black cinema are both neglected topics. I suggest that humor in these films arises out of a particular blend of musical irony, parody, and satire, the exact combination of which is contingent on various historical, cultural, and political factors. In order to track this trend, I analyze humorous music in eight films, each representing a unique manifestation of this tradition: Watermelon Man …