VictorJuiz/thesis huggingface dataset:
Numerical Investigation On Flow Past A Backward Facing Step And Initial Study Of Synthetic Jets

The flow past a backward-facing step and the interaction of a synthetic jet with a duct cross-flow were investigated numerically using an incompressible RANS solver. The numerical result was able to predict the correct flow structure and velocity field for the backward-facing step. The synthetic jet actuator had a cylindrical cavity and the diaphragm movement was modelled physically accurate. The synthetic jet simulated was first validated with experimental data in quiescent flow, the jet velocity profile at peak phases were modelled correctly and net positive momentum was observed in the external region, while the actuator remained net-zero mass flux. The synthetic jet was then integrated into a duct to create a cross-flow, three different blowing ratios were simulated by adjusting the diaphragm vibration amplitude. The simulations allowed the formation of the synthetic jet to be analysed in a low Reynolds number cross-flow and demonstrated that URANS can be used to simulate synthetic-jet in both quiescent and cross-flow.

Keywords: Backward Facing Step
Crossflow
Finite Span Synthetic Jets
Turbulence Modelling
URANS
Advisor: Sullivan, Pierre E
Development and Application of Laminar-specific Gene Expression Meta-analysis of the Human Neocortex

Application of RNA sequencing (RNA-seq) has enabled the characterization of genome-wide gene expression in the human brain, including distinct layers of the neocortex. To advance our understanding of cortical architecture and layer-specific differences in gene expression, we performed a meta-analysis of multiple transcriptomic datasets of gene expression of varying techniques in neurotypical human brains. We observed differences in similarity between bulk-tissue and single-nuclei RNA-seq data, as well as layer-specific enrichment of gene expression. Using the techniques used for the meta-analysis, we developed a web application, LaminaRGeneVis, which allows users to perform similar analyses as performed here. Our results suggest that there is specific enrichment of genes that are relatively consistent across different types of data. These findings and the resulting application provide researchers a platform and reference point to better understand layer-specific gene expression in the human neocortex.

Keywords: Application
Brain
Laminar
Transcriptomics
Advisor: Tripathy, Shreejoy
Supporting Low-latency Transactions in Shared-memory Deterministic Databases

Deterministic databases provide strong serializability while avoiding concurrency-control related aborts. They also simplify replication and provide good scaling in distributed systems. These properties are achieved by batching transactions in epochs and then executing the transactions within an epoch concurrently and deterministically. However, transaction batching leads to high latencies. Our aim is to support certain transactions that we call priority transactions with low latency together with high-throughput batch transactions in a deterministic database. We propose a deterministic concurrency control mechanism that reorders transactions, allowing priority transactions to be serialized with low latency. We implement our approach in the Caracal deterministic database. Our evaluation shows that with 15% priority transactions, their median latency is 35 µs for TPC-C and 10 µs for YCSB, while batch transaction latency ranges between 50-190 ms. The throughput overhead is roughly 9% for uncontended TPC-C and YCSB but 30% for contended TPC-C.

Advisor: Goel, Ashvin
Demke Brown, Angela
Urban Livelihoods and Flood Vulnerability in a State-Sponsored Resettlement Project in Iquitos, Peru

In the Amazon floodplain, the annual flood cycle is an expected part of life; however, anthropogenic climate change is projected to increase the frequency and severity of floods. Further, poor urban residents in the Global South are often disproportionately exposed to floods. Resettlement is increasingly considered a potential climate adaptation policy for high-risk areas, but many past resettlements have failed to improve residents’ wellbeing. In Iquitos, Peru, the Peruvian government has set out to relocate 16,000 residents from Bajo Belén, a low-income neighborhood on the Amazon floodplain. Four hundred households have already relocated to a small settlement 15 km outside Iquitos. This research investigates how relocation changed residents’ livelihoods and vulnerability to floods, using household surveys and interviews conducted during fieldwork in 2019. Findings indicate that residents in Bajo Belén did not always perceive floods as risky, and that relocation has left residents isolated from services and opportunities.

Keywords: Amazonia
environmental hazards
livelihoods
Peru
resettlement
vulnerability
Advisor: Abizaid, Christian
AI in the Workplace: A Scoping Review of Knowledge, Skills and Abilities Required by Employees of the Future

With the recent onset of Artificial Intelligence (AI) in the workplace, I ask how it will affect the knowledge, skills, and abilities (KSA) required by employees to work alongside the new technology. By conducting a rapid, scoping literature review in five most relevant databases I provide an original synthesis on the 168 articles. I find that trust in the new technology is an absolute requirement for employees, and this can be further fostered by ensuring that they have the relevant KSA to work along side AI. Additionally, I identify some of these relevant KSA for employees of the future, and the bring to light the imperative need to redesign roles and processes within organizations. Lastly, I provide a critical view regarding the evolution of AI in the workplace and its affect on the employee, recommending changes that will produce positive outcomes for all involved, especially the most vulnerable employees.

Keywords: abilities
Artificial Intelligence
employees
knowledge
Skills
workplace
Advisor: Sawchuk, Peter
Molecular Characterization of Oncogenic H3.3 K27M and G34R Histone Mutants

Previous studies of H3.3 K27M and G34R identified in pediatric high-grade gliomas have shown they lead to distinct changes on chromatin. K27M results in a global reduction in H3K27me3 through the inhibition of the PRC2 complex, whereas G34R results in reduced H3K36me3 directly on the mutant histone. However, the effects of the mutations beyond these modifications have not yet been fully studied. BioID of the wildtype and K27M and G34R mutant histones identified changes in histone-protein interactions with multiple histone chaperones and methyltransferases. Here, I show that the two mutations did not affect the in vitro interactions with histone chaperones. Additionally, the in vitro activities of K9 methyltransferases EHMT2 and SUV39H2 were altered by the mutations, demonstrating higher activities against G34R and lower activities against K27M histones. This suggests a further deregulation of K9 methylation beyond a deregulation in K36 and K27 methylation accompanying H3.3 G34R and K27M.

Advisor: Hawkins, Cynthia
Campos, Eric
Approach-Avoidance Conflict Processing in Hippocampal Lesion and Aging Populations

Approach-avoidance conflict (AAC) occurs when an organism is simultaneously attracted to and repelled by a goal stimulus, as it cues concurrent possibilities of reward and punishment. A rich body of rodent literature has implicated the hippocampus (HPC) – a medial temporal lobe (MTL) structure traditionally associated with spatial navigation and memory – in AAC processing. These findings have culminated in a model of the hippocampus as exerting inhibitory control over behaviour in AAC scenarios (Gray McNaughton, 2000). Some human studies have provided converging evidence with the rodent literature, but there are comparatively few of them, and they have provided largely correlational evidence of the HPC’s involvement in AAC processing. Additionally, it is unclear whether AAC processing is a unique cognitive process or a special case of more general conflict. Similarly, there is some evidence that the HPC contributes to resolving AAC only with spatial/contextual stimuli (i.e., as opposed to object/item stimuli). The current study employed three versions of a behavioural paradigm designed to elicit AAC, using scene, object, and abstract stimuli, respectively. In a first experiment, we compared the behaviour of patient participants with circumscribed HPC lesions to that of healthy controls. Additionally, two response conflict tasks were administered to determine whether HPC-mediated behaviour differs in AAC and response conflict scenarios. Consistent with our hypotheses, we found that patients approached significantly more often than controls on AAC tasks with scene but not object stimuli. No group differences were observed on the response conflict tasks. We then conducted a second experiment with a modified version of the original AAC tasks, comparing the behaviour of young and older adults. Contrary to our hypotheses, no group differences were observed on either the AAC or the response conflict tasks. These findings and their implications for models of HPC involvement in AAC are discussed.

Keywords: Aging
Approach-Avoidance
Decision-Making
Hippocampus
Lesions
Medial Temporal Lobe
Advisor: Lee, Andy Ch
Ruocco, Anthony C
Effect of Emdogain® on Soft-tissure Wound Healing following Surgical Crown Lengthening Procedures

Enamel matrix derivative (Emdogain®) has been established for years as an agent capable of inducing periodontal regeneration. However, its impact on soft tissue healing is less clear. Various studies have demonstrated enhanced periodontal wound healing as well as reduction of inflammation and discomfort using Emdogain®. A randomized clinical trial was conducted on 22 patients comparing clinician- and patient-based outcome measures as determined by visual analogue scale (VAS) scores. Participants in the Emdogain® group expressed decreased pain and swelling at various follow-up visits on the VAS, with significant reductions noted at week two (2.88mm, p=0.011 for pain and 2.83mm, p

Advisor: Tenenbaum, Howard C
Goldberg, Michael B
Patients’ Information use in an Online Health Community

Patients gravitate toward Online Health Communities when their healthcare professionals areunable to meet their needs. I conduct a discourse analysis using grounded theory to explore the information uses in a Facebook group with over 36,600 COVID-19 patients, survivors, and family members. To understand these information uses, I describe a Facebook Group as an information context, present the four types of contributors in the context, and unpack how the context influences information behaviours. I codify the posts into four themes, explain the information framing of these themes, and collect the respective conversations from the comments. To supplement my analysis, I engage with two moderators and integrate their insights into my analysis. There are few mechanisms for patients, as primary information sources, to relay their insights to medical professionals. My research explores how patients are capturing and sharing the unique knowledge they have about their conditions and the medical system.

Keywords: Covid 19
information use
knowledge creation
online health communities
patient support
Advisor: Choo, Chun Wei
Open-World Few Shot Recognition

As autonomous decision-making agents move from narrow operating environments to unstructured worlds, learning systems must move from a closed-world formulation to an open-world and few-shot setting in which agents continuously learn new classes from small amounts of information. This stands in stark contrast to modern machine learning systems that are typically designed with a known set of classes and a large number of examples for each class. In this work, we extend feature-space em- bedding few-shot learning algorithms to open-world settings. We combine Bayesian non-parametric class priors with a novel network pre-training scheme to yield a highly flexible framework which we refer to as few-shot learning for open-world recognition (FLOWR). We benchmark our framework on open-world extensions of the common MiniImageNet and TieredImageNet few-shot learning datasets. Our results show, when compared to prior methods, strong classification accuracy performance and up to a 12% improvement in H-measure (a measure of novel class detection) from our non-parametric open-world few-shot learning scheme.

Advisor: Waslander, Steven
Noise Tolerance in Quantum Information

Quantum systems are fragile. The decoherence effect, which is caused by interactions between quantum systems and the environment, has been an important barrier for building perfect quantum systems for applications of quantum information science, such as entanglement distribution and measurement-based quantum computing. Researchers have done great efforts both theoretically and experimentally to reduce noises in quantum experiments. In this thesis, we give several theoretical proposals for reducing the effect of noisein different quantum experiments. We calculate the noise bound and give a security proof for high-dimensional QKD protocols for prime power dimensions. We also analyze different QKD protocols, including tomography-based QKD and reference-frame-independent QKD protocols, in different noisy quantum channels to see which protocol gives a higher key rate and noise tolerance. We also propose a new entanglement witness which can tolerate more noise than previous entanglement witnesses.

Advisor: Lo, Hoi-Kwong
Testing the Ensemble: Limitations in the Formation of Cross-modal Ensemble Representations of Taste from Vision

Ensemble coding (the brain’s ability to rapidly extract summary statistics from groups of similar items) has been demonstrated across a range of visual features from low-level to high-level. Ensemble coding has also been demonstrated to operate on information that cannot be gleaned solely from retinal input and must be abstracted (e.g., object lifelikeness, object economic value). I extended this line of research to examine if different sensory modalities can interact during ensemble coding. Participants made judgements about the average sweetness of groups of different visually presented foods. Across three experiments, participants demonstrated the ability to form cross-modal ensemble percepts, albeit with some important limitations. Namely, participants were unable to incorporate all available information into their cross-modal ensemble percepts and utilized a subsampling strategy to make their judgements. Despite potential limits to our ensemble coding abilities, these studies do provide evidence that ensemble coding is more flexible than previously thought.

Keywords: cognitive psychology
ensemble coding
long term memory
perception
vision
visual working memory
Advisor: Cant, Jonathan S
Fukuda, Keisuke
Developing a Gait Monitoring Device for Lower Limb Prosthesis Users

Gait quality significantly affects the physical and mental health of lower limb prosthesis users. In this work, a wearable gait monitoring system was developed for lower limb amputees (LLAs) who use prostheses. The microcontroller-based sensing system consists of force-sensing resistors (FSRs) and inertial measurement units (IMUs), attached to a custom-designed show cover. Data acquired by the sensors were processed to determine and display temporal gait parameters on a mobile application. This device is simple and easy to don and doff, which makes it a convenient solution for objective gait monitoring in clinical rehabilitation. To evaluate the device performance, a case study investigated its application in assessing the effectiveness of interventions on gait quality. The gait monitoring system was able to detect improvements in gait parameters following the chosen intervention (gait imitation). A future study will investigate the feasibility of using the developed sensing system in a clinical setting.

Advisor: Azhari, Fae
Transfer Reinforcement Learning Across Tasks with Dynamics Mismatch

Reinforcement Learning has recently emerged as a viable solution for various sequential decision-making problems. However, standard Reinforcement learning agents require a large number of samples to learn effectively and transfer learning is a mechanism aimed at alleviating this issue. When transferring knowledge from already mastered source tasks to a new target task, the similarity between the source and target task can play a crucial role in determining the usefulness of transfer. This thesis showcases the utility of one such measure of task similarity, based on the upper bound of the differences in optimal state-action values, as a gatekeeper for selective transfer in the transfer learning setting where the previously solved tasks and current task differ with respect to the transition dynamics. Numerical results, including a novel application of transfer learning for epidemic spread control, demonstrate the benefits of preventing negative transfer while accelerating learning otherwise.

Advisor: Lee, Chi-Guhn
Measuring Multimorbidity, Classifying Potentially Inappropriate Medications and Investigating Polypharmacy in Recipients of Medication Reviews and Pharmacy Dispensing Services Conducted by Ontario Community Pharmacists

Factors including aging and health related behaviours lead to multimorbidity, polypharmacy and potentially inappropriate medications (PIMs). Medication reviews conducted by community pharmacists can improve medication management. Patient data were extracted from three community pharmacies in Ontario. Multimorbidity scores and number of PIMs were determined. Construct validity was assessed via linear regressions with age and sex. Consistency among multimorbidity measures was assessed via Pearson correlation coefficients. The mean multimorbidity scores determined by disease counts, Charlson Index, Chronic Disease Score, Medication Based Disease Burden Index, and Rx-Risk measures were 4.9 (SD 2.3), 4.4 (SD 2.0), 7.1 (SD 3.6), 0.1 (SD 0.2), and 0.4 (SD 1.7) respectively. Most analyses supported construct validity and consistency among measures. Patients were taking a mean of 1.9 (SD 1.5) and 2.0 (SD 1.4) PIMs determined by the 2019 American Geriatrics Society Beers criteria and STOPP criteria respectively. The analyses can lead to the improved management of multimorbidity.

Keywords: community pharmacy
multimorbidity
pharmacist
polypharmacy
potentially inappropriate medications
Advisor: Dolovich, Lisa
Investigating the Impact of Temperature and Oxygen on Preservation Injury after Ex vivo Kidney Perfusion

Kidney transplantation improves the lives of patients with end-stage kidney disease, and extends their life expectancy. Ex vivo machine perfusion has been extensively explored in past years for the storage and assessment of expanded criteria kidney grafts and donation after cardiac death grafts. Both normothermic and hypothermic machine perfusion techniques have benefits and shortcomings. In a porcine model, we found that grafts preserved with continuous and end-ischemic normothermic ex vivo machine perfusion (NEVKP) show better graft function demonstrated by lower peak serum creatinine and higher creatinine clearance than grafts preserved with hypothermic machine perfusion with and without oxygen. Moreover, we demonstrated that subnormothermic and normothermic machine perfusion result in comparable graft function after transplantation, even if metabolic function is reduced during subnormothermic perfusion. In a pilot clinical study, we evaluated graft and patient survival after end-ischemic NEVKP and could demonstrate the safety and feasibility of NEVKP for human deceased donor transplantation.

Keywords: Kidney Transplantation
Machine Perfusion
Organ regeneration
Advisor: Robinson, Lisa A
Selzner, Markus
Optimization of Pin Fin Heat Sinks for High Power Density Electronics Using Genetic Algorithm Coupled with Computational Fluid Dynamic Modelling

The development of high-power electronic devices in various energy systems has recently gained attention for electric vehicles and hybrid electric vehicles. However, the increase in power density has also introduced several design challenges especially in thermal management. This thesis attempts to optimize a liquid cooled pin fin heat sink with localized heat sources representing an EV power driver using genetic algorithm (GA). Both pin geometry and pin locations are optimized to reduce thermal resistance and pressure drop of the coolant. Computational fluid dynamics (CFD) simulation is used in the genetic algorithm to evaluate the performance of each potential design during optimization. A set of optimizations with different geometric parameters has been carried out and compared. The results demonstrate that GA coupled with CFD may be a powerful tool for designing an effective and reliable heat sink for high power density applications.

Keywords: CFD
genetic algorithm
heat exchanger
thermo-fluid dynamic
Advisor: Mills, James K.
Bayesian Preference Elicitation and Critiquing for Conversational Recommendation

In the conversational recommendation setting, a user often has long-term preferences obtained from previous interactions along with temporary session-based preferences that need to be inferred through minimal interaction, either driven by the system~(i.e. preference elicitation) or by user~(i.e. critiquing). This thesis aims to extend the Bayesian paradigm of belief updating after each interaction for language-based conversational recommendation and focuses on addressing the following open problems: (1) existing Bayesian preference elicitation methods have typically focused on eliciting preferences in the space of items or small set of explicitly known objective attributes, and (2) existing methods for critiquing do not use Bayesian methods for managing uncertainty and rely on overly complex architectures that can perform poorly in practice.We empirically validate all contributions in comparison to non-Bayesian baselines and demonstrate the strong advantages of the novel methodologies proposed in this thesis.

Keywords: Conversational Recommendation
Recommender Systems
Advisor: Sanner, Scott
“Our Families are Fearless”: Navigating, Resisting, and Building beyond Settler Colonial Demands for ‘Reasonableness’ at the Violent Intersections of Housing and Child Welfare Systems in Winnipeg’s North End

While analysis of the relationship between housing and child welfare is limited in the Canadian academe, the same cannot be said of discussions on the ground: in North End Winnipeg, many Indigenous caregivers are acutely aware of the complex intersections between their housing quality and their ability to bring and/or keep their children home. Landlords, social workers and government officials are adamant that their respective institutions operate according to universally ‘reasonable’ rules – however, interviews with caregivers and a secondary analysis of non-profit tenant advocacy files reveal that each settler colonial system’s ‘reasonable’ demands frequently conflict and contradict to create fundamentally unreasonable expectations of parents. This research gathers together caregiver stories to map out the violent material and immaterial intersections of the child welfare and housing systems in intimate spaces of home, as well as how Indigenous caregivers strategically comply, resist, and build alternatives to keep their families housed and whole.

Keywords: Child Welfare
Housing
Indigenous Resistance
Parent Rights
Settler Colonialism
Winnipeg
Advisor: Hackworth, Jason