Theses

Permanent URI for this collectionhttps://uwspace.uwaterloo.ca/handle/10012/6

The theses in UWSpace are publicly accessible unless restricted due to publication or patent pending.

This collection includes a subset of theses submitted by graduates of the University of Waterloo as a partial requirement of a degree program at the Master's or PhD level. It includes all electronically submitted theses. (Electronic submission was optional from 1996 through 2006. Electronic submission became the default submission format in October 2006.)

This collection also includes a subset of UW theses that were scanned through the Theses Canada program. (The subset includes UW PhD theses from 1998 - 2002.)

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Neurovascular Coupling in healthy human retina evaluated with Optical Coherence Tomography
(University of Waterloo, 2024-12-21) Dhaliwal, Khushmeet
Retinal neurodegenerative diseases such as glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa affect millions of people worldwide and pose a significant burden on public health and the economy. Glaucoma, impacting approximately 80 million people globally, is a leading cause of irreversible blindness. In 2019, an estimated 19.8 million Americans (12.6%) were living with AMD, of which about 1.49 million people faced vision-threatening conditions. An estimated 9.6 million people were living with diabetic retinopathy in 2021, with about 1.84 million of them experiencing vision-threatening stages. In the United States alone, vision impairments- including those resulting from these retinal diseases- cost an estimated $139 billion annually. Retinal neurodegenerative diseases not only cause progressive damage to the retinal morphology and vascular network, but also cause acute and transient metabolic, physiological, and blood flow changes at the early stages of the disease development which become permanent and chronic at the advanced stages of the disease. Neurovascular Coupling (NVC) refers to the transient vasodilation and increased retinal blood flow resulting from the increased metabolic activity of retinal neurons in response to visual stimulation. Over the past few decades, a range of imaging techniques from clinical ophthalmoscope and confocal microscopy to adaptive optics scanning laser ophthalmoscope and optical coherence tomography (OCT) have been used ex vivo and in vivo to study components of the neurovascular coupling and its underlying mechanisms. Techniques such as Laser Doppler Velocimetry, Optical Coherence Tomography Angiography (OCTA), and Doppler Optical Coherence Tomography (D-OCT) have been used to observe the vascular responses of the retina caused by visual stimulation. Additionally, Electroretinography (ERG) has been widely used in clinical settings to evaluate the electrical activity of the neuronal retina. More recently, an optical equivalent to ERG, Optoretinography (ORG) was developed and OCT technology, imaging protocols, and image processing algorithms were designed to conduct OCT-based ORG studies in the human and animal retina. However, most of the Doppler OCT, OCTA, and ORG studies have examined components of the neurovascular coupling separately, potentially overlooking the dynamic interactions and comprehensive responses inherent in neurovascular coupling. OCT, which acquires simultaneously both intensity and phase information, is particularly well-suited for investigating neurovascular coupling in the retina, as it enables a completely non-invasive approach for simultaneous monitoring of retinal blood flow dynamics and neuronal responses. The integration of a commercial ERG system with a research-grade OCT modality adds further value by offering easy control of the visual stimulus, use of clinically established ERG protocols designed to elicit responses from specific types of retinal neuronal cells, and using the ERG recordings to validate the visually-evoked neuronal responses. The main objectives of this PhD thesis were: 1. To develop a combined OCT+ERG imaging system to conduct in vivo and simultaneously morphological and functional imaging that can be utilized for investigating neurovascular coupling in the human retina. 2. To evaluate the performance and capabilities of the OCT+ERG system, imaging protocols, and image processing algorithms by conducting a pilot study on healthy human subjects. 3. To utilize the OCT+ERG technology to explore the neurovascular coupling mechanisms in the healthy human retina by extracting vascular and neuronal responses from different retinal layers simultaneously. 4. To examine the effects of different wavelengths and flicker frequencies on the dynamic retinal blood flow changes evoked by visual stimulation, providing deeper insights into the mechanisms of neurovascular coupling. Results from this PhD research have been summarized in three manuscripts that are either under review or under preparation for submission. Therefore, this PhD thesis was prepared in such a way that individual manuscripts represent separate thesis chapters.
From Fisher Economicus to Fisher Socialis: Investigating the Role of Fisher Behaviour for Effective and Equitable Governance
(University of Waterloo, 2024-12-20) Battaglia, Maria Bernadette
The purpose of this dissertation is to advance the emerging field of fisher behaviour. The applied aim is to enhance fisheries and oceans policy, and primarily within the context of small-scale fisheries sustainability. In this dissertation, fisher behaviour is defined as the actions (or inactions) taken by fishers in response to internal and external stimuli and it describes the multitude of ways in which fishers interact with their social and ecological environment. Further, fisher behaviour can manifest through physical action, verbal expression, emotional responses, and cognitive processes. Fisheries and oceans policy shapes and is simultaneously shaped by fisher behaviour because regulations and enforcement mechanisms that emerge from policy interventions signal what behaviours are allowed and which ones are not. Fishers, in turn, interpret these signals based on their values, needs, and perceptions of legitimacy over resource use. For this reason, when policy does not adequately reflect the diverse range of factors that shape fisher behaviour, regulations can become inefficient or inequitable and may result in poor social and ecological outcomes. Despite the importance of behaviour and its central role in the pursuit of fisheries and oceans sustainability, fisher behaviour is complex and hence still not well understood. Historically, predominant paradigms of behaviour have been based in neoclassical economics’ Homo Economicus. These models of behaviour predict that rational and self-interested individuals will always prioritize personal gain over the collective interest and, without external interventions, they will inevitably deplete shared resources. Yet, in the last few decades, empirical evidence has challenged these assumptions, and has shown that resource users, including fishers, are able and willing to engage in collective action to solve social dilemmas. The scope of this dissertation is to use the emerging field of fisher behaviour as a critical lens to strengthen fisheries and oceans policy. To achieve this overarching aim, this dissertation is guided by three interrelated research objectives: 1) To advance and understand fisher behaviour as an emergent and critical, yet understudied, field through the development of a comprehensive conceptual typology based on selected literatures; 2) To map and synthesize the complex interactions between social norms (as a particular manifestation of fisher behaviour), collective action problems, and fisheries policy and to further unpack the role of social norms as a catalyst of collective action in natural resource systems, including in fisheries systems; and 3) To empirically examine the role of social norms and social networks as two fisher behavioural approaches and further assess their implications for policy. The first objective provides the foundation of this dissertation and frames the context and significance of this research by presenting an overview of alternative behavioural approaches to understand fisher behaviour. The second and third objectives delve deeper into two behavioural approaches, and in doing so, they challenge one of the core assumptions of Homo Economicus: that humans are self-interested, hence incapable of solving collective action problems. The research methodology used in this dissertation is informed by deductive and inductive approaches and the integration of qualitative and quantitative methods, alongside a theoretical exploration. To further understand fisher behaviour in real world settings, a case study was conducted in Sardinia, Italy, in the context of three small-scale fishing communities adjacent to the Asinara MPA. Fieldwork was conducted both in-person and coordinated remotely in response to COVID-19 pandemic requirements. Research instruments were co-developed in collaboration with BMF, a not-for-profit organization working in the area, and further reviewed by key community informants to ensure coherence with the local context. Further, informal conversations with research partners and members of the local communities added additional depth and confirmed the direction of the research findings. In Chapter 2, a theoretical exploration of existing literature on fisher behaviour was adopted to provide a typology of key selected approaches that offer an interdisciplinary suite of entry points and complementary opportunities to advance the understanding of fisher behaviour. These approaches include theories, concepts, and perspectives from Critical Social Theory, Systems Approaches, Development Scholarship, and Institutional Scholarship. Two vignettes, one based in Italy, and one based in Canada, were included in this chapter to add further empirical weight to the chapter by delving deeper into two of the lenses presented in the typology. In Chapter 3, a systematic scoping review was used to map and synthesize existing literature on social norms in fisheries. However, given the limited availability on empirical articles that focused solely on fisheries, the scope of the evidence synthesis was broadened to include other environmental contexts. As such, the systematic scoping review was conducted on peer-reviewed articles (n=69) to map and synthesize ways in which social norms are conceptualized, elicited, and measured in the empirical literature at the intersection of social norms and collective action problems in environmental settings. This evidence synthesis followed the PRISMA-ScR. Findings revealed that social norms can be conceptualized as collective or individual constructs, and they can be elicited or measured using a variety of qualitative and quantitative methods. Further, social norm definitions do not necessarily correspond to a unique elicitation method. These results suggest that what may initially appear as lack of coherence is instead an opportunity to study social norms from various angles and perspectives. In Chapter 4, structured surveys (n=81) were used to empirically examine the role of social norms and social networks in the Asinara MPA communities. Findings indicated that the existence of subgroups within networks does not necessarily hinder capacity for collective action, as analyses on the strength and distribution of social norms showed that cooperative behaviours within the Asinara MPA communities were still strong. Importantly, network analyses also elicited the presence of well-connected, central actors within each subgroup. This finding holds promising potential for collective action because central figures can leverage their positions to synthesize subgroup heterogeneity and generate innovative solutions to shared challenges. Findings and insights of this dissertation contribute to advancing the emerging field of fisher behaviour, while offering alternative approaches to the paradigm of behaviour based in Homo Economicus. Context-relevant knowledge on fisher behaviour can be operationalized in policy settings to catalyze change using insights on who fishers are and the reasons behind their actions. For instance, Challenge 10 of the United Nations 2021-2030 Decade of Ocean Science for Sustainable Development aims to identify barriers to behaviour change to achieve ocean health. However, this aim cannot be achieved using models of human behaviour that underserve and oversimplify the complexity of empirical reality. Findings from this dissertation translate into theoretical and empirical contributions by helping identify lenses and approaches to enhance fisheries and oceans policy, through a more comprehensive understanding of fisher behaviour. These insights can support policy in three complementary ways. First, knowledge on fisher behaviour can enhance coherence between policy and the social context within which policy instruments are embedded, which includes the behavioural elements of social systems, such as fishers’ values, needs, and beliefs. Second, aligning policy with contextual knowledge about fisher behaviour can improve policy equity by bringing recognition to pre-existing forms of organization (e.g., social networks) and informal rules of behaviour (e.g., social norms) that fishers have developed over long periods of time and persistence. Finally, this research reveals that there are currently untapped opportunities to generate new evidence about fisher behaviour. However, these efforts will require challenging the assumptions that have long underpinned fisheries and oceans policy, and cultivating collaborations across academia, policy practitioners, and fishing communities to inform the development of new methodologies and contextually-relevant understandings.
Computational study of cellular adhesion in metastasis: Implications for Circulating Tumor Cell Arrest, Extravasation, and Thrombosis Formation
(University of Waterloo, 2024-12-20) Rahmati, Nahid
Cancer metastasis is the process by which cancer cells spread from the primary tumor to distant sites in the body, forming secondary tumors. This process is responsible for the majority of cancer-related deaths, despite significant advancements in treating primary tumors. This thesis aims to enhance the understanding of metastasis mechanisms by exploring the roles of circulating tumor cells (CTCs), ultra-large Von Willebrand Factor (UL-VWF) multimers, and blood vessel configurations. This study focuses on the mechanical, biochemical, and hemodynamic factors that drive metastatic processes and cancer-associated coagulopathies, providing insights into the interactions between CTCs, VWF, and endothelial cells. Through computational modeling and simulations, first, we investigate the role of UL-VWF multimers in cancer-associated thrombosis. The computational model integrates the lattice Boltzmann method for simulating blood flow, a coarse-grained model for deformable cells to capture their mechanical behavior, and the immersed boundary method to handle fluid-structure interactions. Additionally, an adhesion model was developed to simulate the binding dynamics between cells. This multi-scale approach allows for a detailed analysis of how UL-VWF multimers interact with blood cells to initiate microthrombus formation and progression. The findings reveal that UL-VWF plays a dual role in thrombosis and metastasis, enhancing platelet adhesion and trapping red blood cells, which can lead to significant changes in blood flow dynamics, such as reduced velocity and increased shear stress near thrombus sites, leading to a pressure drop of up to six times compared to healthy conditions. The study also explores the impact of blood vessel architecture on CTC dynamics, focusing on how vessel tortuosity influences CTC adhesion and extravasation. The same computational methodology has been utilized to analyze CTC interactions with the vessel wall, incorporating adhesion dynamics between the CTCs and the endothelial surface while considering the effect of shear rate on adhesion strength. The results indicate that curved vessels create asymmetrical flow patterns, resulting in variable shear stress, a 25% decrease in the wall shear stress in low-shear regions and a 58.5% increase in the high-shear region, that significantly affects CTC behavior. Specifically, high-shear regions in curved vessels show a threefold rise in adhesion bond formation compared to straight vessels, enhancing the likelihood of CTC extravasation. Increasing the tortuosity index of the vessel led to a 50% increase in maximum wall shear stress ratio and a 15.3% decrease in minimum wall shear stress ratio, as well as a 58% increase in the transit time of CTCs through the vessel curvature. The adhesion force in these high-shear regions increased by about 171%, indicating a significantly higher risk of CTC adhesion and extravasation in vessels with higher curvature. Additionally, while softer CTCs in low-shear regions showed a higher likelihood of detachment, stiffer cells in high-shear regions exhibited a reduction of approximately 12% in adhesion force compared to their behavior in straight vessels. This study identified an optimal range of cellular stiffness for successful CTC extravasation, challenging the assumption that softer cells always extravasate more efficiently. In this thesis, we also employed a stochastic model to analyze the dynamics of CTC adhesion, a crucial factor driving metastasis, incorporating parameter uncertainties in cell mechanical properties and adhesion characteristics. This probabilistic approach realistically captures the biological variability inherent in CTC behavior by accounting for a wide range of possible cell adhesion scenarios. Our analysis revealed that incorporating parameter variability, with a coefficient of variation of 20%, led to a maximum uncertainty of 12% in cell velocity. This variability manifested in two distinct CTC behaviors: either the cells detached from the vessel wall or continued to roll in a semi-stable manner, emphasizing the non-linear and complex nature of the adhesion dynamics. To efficiently manage computational demands, we developed a Random Forest surrogate model, achieving a high level of accuracy with a maximum error of 4.36% for velocity and 0.63% for stretch ratio. This model enabled comprehensive sensitivity analysis using Sobol' and E-FAST methods, which identified the bond spring constant and rupture strength as the most influential parameters following the initial adhesion phase, while cell membrane elasticity played a critical role during the initial adhesion. We also observed significant interdependencies between bond formation and rupture properties, underscoring their combined impact on CTC dynamics. Furthermore, machine learning techniques, particularly XGBoost, validated the model's predictive capabilities by achieving a classification accuracy of 95.62% and an area under the curve (AUC) value of 0.99 in distinguishing between 'rolling' and 'detached' CTC states. These findings highlight the importance of focusing on key parameter interactions to refine predictive models for metastasis. This comprehensive approach builds on the computational frameworks developed in this thesis, enhancing our understanding of metastasis by offering predictive insights into CTC behavior under different conditions. By integrating these findings into a cohesive framework, the thesis supports the development of more targeted therapeutic strategies to prevent or disrupt cancer progression.
A Community-Based Exploration on the Impacts of Land-Based Learning in an Urban Indigenous Community
(University of Waterloo, 2024-12-20) Bui, Danica
Background Connection to the Land is essential for Indigenous Peoples’ health and well-being. Indigenous Food Sovereignty works towards regaining control over traditional food systems. There is a need for sustainable, Indigenous-specific, and accessible urban community Land-based practices. Done in partnership with White Owl Native Ancestry Association (WONAA) and the Wisahkotewinowak Collective (WC), four seasonal Land-based learning events were held. Each event involved a workshop, meal, and gathering at the University of Waterloo’s North Campus Community Gardens. Aims Guided by the interests of project partners, WONAA and WC, the overall purpose of this thesis is to explore and evaluate the impacts of Land-based learning on the local Indigenous and university communities and the PEG project’s effectiveness in establishing networks to facilitate ongoing research and learning to establish a permanent Land-based learning space on campus. The overarching research questions that guided the research are: 1. What are participants’ and facilitators’ perceptions of the Land-based engagement process? 2. What is the effectiveness of Land-based workshops in identifying and prioritizing collaborative Land-based opportunities for learning and research? 3. To what extent can the seasonal workshops establish a local network to facilitate ongoing research and learning in support of the development of an urban Indigenous Land-based learning space on the UW campus? Methods Appreciative Inquiry and Community-Based Participatory Research approaches were used for this thesis. Following each of the events, participants and project collaborators were recruited to participate in interviews. The data for this evaluation was collected through 17 semi-structured interviews with project collaborators and community partners (n=6), urban Indigenous community members (n=6), Indigenous youth and students (n=2), and UW staff (n=3), two focus groups with WONAA and WC staff members (n=5) that were involved with the workshops, and a document review. Reflexive thematic analysis was completed using NVivo for the interview and focus group transcripts, and the documents were analyzed to determine if the budget and timelines were met. Results Overall, participants, collaborators, and facilitators of the Land-based learning events had positive perspectives of establishing a Land-based learning space on campus. The three key themes from the interviews about the Land-based learning events and their potential for building connections to establish a permanent Land-based learning space include: (1) participants’ growing support of Land-based learning (2) creating connections and building relationships and (3) institutional support and project sustainability to support of the development of a permanent urban Indigenous Land-based learning space. The findings from the outcome evaluation, including the interviews, focus group, and documents reflect these themes and include (1) workshop feedback (2) project partners' goals, and (3) identifying opportunities to move forward. These findings show that the community, including project partners, participants, and collaborators, found the Land-based learning events to be a welcoming and positive experience that should become integrated into university curricula to support the university and local community. Conclusion Participants enjoyed the Land-based learning events and supported the establishment of a permanent Land-based learning space at the North Campus Community Gardens. Attending the events and being involved in the project generated ideas for learning and research opportunities, with many participants sharing future workshop ideas and identifying ways to integrate Land-based curricula and research opportunities. The events also connected the local urban- Indigenous community to the university community and helped to strengthen pre-existing relationships between the attendees. Through these connections, the desire for the North Campus Community Garden to become a space for Indigenous learning, teaching, and research, strengthened. Overall, the interview and focus group participants had positive perspectives of the events and the establishment of a permanent Land-based learning space at the North Campus Community Gardens, shared that Land-based learning was a need in the urban Indigenous and university community, and emphasized that further support from UW, longer-term funding, and physical and social infrastructure was needed for the project’s sustainability.
A Two-Effects Model of Explanation on Exposing the Illusion of Understanding
(University of Waterloo, 2024-12-20) Meyers, Ethan
People often overestimate their understanding of how things work. For instance, people believe that they can explain even ordinary phenomena such as the operation of zippers and speedometers in greater depth than they really can. This is called the illusion of understanding (originally known as the illusion of explanatory depth). Fortunately, a person can expose the illusion by attempting to generate a causal explanation for how the phenomenon operates (e.g., how a zipper works). This might be because explanation makes salient the gaps in a person’s knowledge of that phenomenon. However, recent evidence suggests that people might be able to expose the illusion by instead explaining a different phenomenon. Across six preregistered experiments and one secondary data analysis, I examined whether explaining one phenomenon (e.g., how a zipper works) leads individuals to lower their self-assessed knowledge of unrelated phenomena (e.g., how snow forms). My findings demonstrated that participants consistently revised their understanding downwards, not only for the item they explained but also for other items they did not explain. For instance, participants reported reduced understanding of speedometers after explaining helicopters or zippers. Contrary to prior research, participants did exhibit the illusion for familiar movie plots (Experiment 4), but consistent with prior research, participants did not exhibit the illusion for common procedures (Experiment 5). Additionally, when common procedures were included in the experimental design used in Experiments 2 and 3, participants showed no illusion whatsoever (Experiment 6). Finally, an analysis of explanation quality using ChatGPT to code the explanations revealed that the reduction in perceived understanding after explaining (compared to before) correlated with the difference between how well the participant thought they understood the item and how well they actually explained it, but only for explained items. These findings challenge the common framework of how the illusion of understanding operates. Throughout the thesis I evaluate alternative models of the illusion and ultimately find the most support for a two-effects model of explanation, wherein failing to explain a phenomenon temporarily makes people recognize the gaps in their knowledge of the item they explained and makes them feel less knowledgeable about most other things.
Exploring the Use of Managed Retreat in Canada's Policy Domain
(University of Waterloo, 2024-12-19) Cottar, Shaieree
The use of managed retreat is growing and will continue to evolve within Canada’s policy domain to better adapt to the realities of climate change. Climate induced managed retreat involves the strategic relocation of people, assets and critical infrastructure from high-risk areas via the use of government funded property acquisitions (buyouts). Amid increased flood risks and rising recovery costs, communities in Canada have recognized that conventional approaches to flood risk management (FRM) are no longer sustainable and will require the use of practical policy solutions, such as managed retreat, that are cost-effective, politically viable, and publicly accepted. Given the growing adaptation deficit in municipalities, there is an inherent need to identify the policy gaps and barriers to implementation, analyze the policy levers, and explore opportunities for future managed retreat policy and program development. Rooted in the climate change adaptation and disaster risk reduction literature, this dissertation explores the theoretical tenets of FRM, particularly the lack of alignment between flood risk governance, risk reduction and risk prevention through the empirical application of post-disaster managed retreat policies in Canadian communities. The current policy discourse in Canada focuses on the development of a subsidized national flood insurance program whilst provincial jurisdictions like British Columbia (BC) are contending with how to amend existing disaster and emergency management policies to effectively integrate community led managed retreat. Similarly, provinces like Quebec have significantly advanced in their progress and have implemented multiple buyout cycles as part of their disaster financial assistance programs. By analyzing multiple case studies across different timeframes during their recovery process, this dissertation investigates the complex post-disaster decision-making process amongst different levels of government and explores potential pathways towards building climate resiliency. Through three interrelated qualitative studies, this research documents the development, application and implementation of managed retreat buyout programming and its wider implications for communities. The findings suggest that flood disasters often act as focusing events and open policy windows during the post disaster recovery stage providing an avenue for renewed disaster recovery discussions including the use of managed retreat as a policy tool which may not be politically justifiable in a proactive context. A case study analysis critically documents the recovery process by analyzing municipal perspectives on managed retreat and flood mitigation signaling a shift from a hazards-based to a risk-informed approach in Merritt, Canada after the 2021 flood disaster. Moreover, existing path dependencies and outdated disaster policies can favour recovery decisions and limit the types of mitigation measures that are considered by jurisdictions. Likewise, the development of a buyout program for flood mitigation purposes should account for design considerations that include community led and pricing methodologies that follow an equity-based approach. While the use of buyouts is an important tool to become climate resilient, partially retreated communities must strategically develop land use plans that reconcile the benefits of floodplain restoration and provide recreational spaces for public use. A longitudinal study analyzes the institutional alignment of provincial buyouts policies and regulatory tools in Gatineau, Canada, five years after the Quebec Spring 2019 floods. In broader terms, this dissertation ascertains that in the face of surging disaster costs and conflicting governmental priorities, the use of managed retreat will continue to grow and evolve within the Canadian policy arena as a viable climate adaptation and risk reduction strategy. As a result, this critique presents novel approaches for evaluating managed retreat policies to minimize the negative impacts on communities whilst maximizing the co-benefits. Moreover, this dissertation makes key contributions to the managed retreat literature by linking the topics of flood risk governance, flood risk management, and applied policy. The research provides valuable insights for policymakers on buyout policy development, program implementation, and long-term land use plans for communities in Canada.
Modifications of Zein Biopolymer for Material Applications: Biopolymer Blends, Films, Bioactive Delivery Nanoparticles, and Nanofibers
(University of Waterloo, 2024-12-19) Tadele, Debela
The need for sustainable and high-performance materials is becoming increasingly urgent as society confronts escalating environmental challenges and pressing healthcare demands. Zein, a protein derived from corn, offers promising potential as a renewable, biodegradable, and biocompatible material for various applications. However, its utility is hindered by intrinsic limitations, such as poor processability, inadequate mechanical properties, and limited thermal stability. This research aims to address these challenges through chemical modifications of zein, blending with complementary polymers, and employing advanced fabrication techniques to develop nanoparticles and nanofibers for targeted applications. The first part of this study focused on chemically modifying zein via esterification using fatty acid chlorides of varying chain lengths (C6, C10, and C16). The findings revealed that fatty acid-modified zein exhibited significantly enhanced hydrophobicity, improved melt processability, and superior tensile properties compared to unmodified zein. The introduction of fatty acid chains also acted as internal plasticizers, facilitating the creation of a melt-processable biopolymer suitable for scalable production. In the second phase, the modified zein (mZein) was blended with poly(butylene adipate-co-terephthalate) (PBAT) via melt extrusion to fabricate biodegradable films. The study explored the effects of varying blending ratios on the compatibility, morphology, and physicomechanical properties of the films. It was observed that the esterification with decanoic acid (C10) significantly enhanced mZein's compatibility with PBAT, enabling the formation of films with balanced mechanical and barrier properties. A composition of mZein/PBAT at 30/70 wt% exhibited optimal performance, achieving a tensile strength of 10.88 MPa, elongation at break of 561.41%, and a modulus of 105.63 MPa. Furthermore, the blend demonstrated superior oxygen barrier properties, reduced water vapor permeability, and improved disintegration rates, making it suitable for food packaging and agricultural applications. The third component of this research examined zein as a biopolymer matrix for nanoencapsulation of bioactive compounds, specifically quercetin and α-tocopherol. Zein nanoparticles (ZNPs) were fabricated using a green antisolvent co-precipitation method, achieving encapsulation efficiency of 96% with particle sizes ranging from 50 to 320 nm. Co-encapsulation of quercetin and α-tocopherol in various formulations revealed distinct release dynamics, with the Zein/Que/Toc (20:1:1) formulation demonstrating controlled release rates over 8 hours. ATR-FTIR and fluorescence spectroscopy highlighted the hydrogen bonding and hydrophobic interactions critical to the encapsulation mechanism. In the final phase, α-tocopherol-encapsulated zein was integrated with polyvinyl alcohol (PVA) to produce nonwoven fiber mats via solution blow spinning. These mats exhibited uniform fiber morphology (diameter: 350–796 nm), excellent mechanical properties, and sustained release of α-tocopherol over 24 hours. Cytotoxicity assessments confirmed high cell viability (>90%) and enhanced cell spreading, suggesting the potential for biomedical applications such as wound dressings. Overall, this research contributes significantly to the fields of biodegradable polymers and bioactive delivery systems. By overcoming the intrinsic limitations of zein through chemical modification and advanced processing techniques, this work offers a scalable framework for the development of high-performance sustainable materials. These findings have broad implications for applications in food packaging, agriculture, pharmaceuticals, nutraceuticals, and biomedical sciences, paving the way for more environmentally friendly and functional material solutions.
Let it Flood: Rethinking Flood Resilience for Indigenous Homes and Heritage
(University of Waterloo, 2024-12-19) Goel, Vani
Indigenous communities are not just the inhabitants of the land they live on, they are its stewards, storytellers and souls. Their homes, often passed down from one generation to another, hold the stories of their ancestors, struggles, and the rituals that define their sense of place. Yet, time and again, these communities are forced to evacuate due to flooding, temporarily uprooted from the lands they call home. Throughout Canada’s colonial history, numerous Indigenous communities have been displaced onto remote, flood-prone land increasing their vulnerability to floods. The impact of these repeated displacements ripple through the communities, disrupting cultural heritage, age-old traditions, and the sacred connection between land, water and people. This creates a profound sense of loss—both tangible and intangible. Many communities have felt the impacts that some residents were never able to return home, faced with the difficult decision to abandon their multigenerational homes. With floods growing in frequency and intensity, the urgency to address the impacts of climate change is more pressing than ever. Beyond the cultural, social and mental toll, the economic burden of rebuilding is staggering, with billions spent on recovery and reconstruction. Communities without access to substantial resources for protective measures often bear the brunt of the impact. But while the physical structure of a home can be rebuilt, can one really rebuild and recover a sense of belonging? This thesis advocates for amphibious architecture as a resilience-in-place approach—a way for Indigenous communities to remain safe on their land, even when floods come. Unlike relocation, which severs the deep bonds between people and place, amphibious architecture allows homes to rise with the water and settle back once it recedes, offering the possibility of living in harmony with natural cycles, rather than in fear of them. By exploring how this architectural form can be applied across Canada and incorporated into policies and regulations, I argue for a future where Indigenous communities need not choose between safety and staying on their homeland. This work is about more than protecting homes from floods; it is about safeguarding the cultural continuity and the deep connection to land that relocation threatens to erase. Ultimately, it raises the question of how architecture can protect and preserve the sacred bonds between land, water, and people, fostering a more resilient and equitable tomorrow.
Shipment Consolidation in Hub Location Modelling
(University of Waterloo, 2024-12-19) Shah, Khaled Mostafa
This thesis examines the integration of shipment consolidation and inventory holding decisions with the design of hub networks, where a heterogeneous fleet is used for inter-hub transportation. These problems aim to determine the optimal locations of hubs, allocate demand nodes to them, decide the quantity of inventory to be held at hubs, and assign vehicles from the heterogeneous fleet to operate on hub arcs. This is done while considering inventory storage space at hubs and vehicle capacities. These decisions are made to fulfill a set of demands for flows between origin-destination pairs, distributed across a multi-period planning horizon. Prospective applications of this work include air cargo, less-than-truckload transportation, express shipments, and postal delivery systems. The first problem studies shipment consolidation and inventory holding in a single allocation hub location problem, which considers a promised delivery time for goods. The goal is to jointly determine the optimal hub locations, allocation of demand nodes to hubs, inventory levels to be held at hubs in each time period, and the type and number of vehicles to be dispatched on inter-hub links in different periods. The objective is to minimize the total cost of infrastructure, transportation, and inventory holding. This problem is formulated as a mixed-integer programming model. To solve larger instances, we propose a variable neighborhood search-based algorithm that incorporates a shipment consolidation sub-problem. Computational experiments with varying parameter values, conducted on a realistically created dataset, demonstrate the comparative effectiveness of the networks generated by both the model and algorithm. The second problem in this thesis explores the integration of operational decisions regarding shipment consolidation and inventory holding within a hub arc location model for a freight network. In contrast to the first problem, the focus is on locating hub arcs rather than hub nodes. The allocation of demand nodes to multiple hub arcs is allowed in this setting for greater flexibility in routing and consolidation, and the optimal frequency and types of vehicles operating on those hub arcs are also to be determined. A mixed-integer programming model is proposed to minimize the total cost of hub arcs, transportation, and inventory. It determines the optimal location of hub arcs, allocation of demand nodes to these arcs, inventory levels at the origin nodes of hub arcs in each time period, and the type and frequency of vehicles from a heterogeneous fleet to operate on the hub arcs. To solve the problem efficiently, a Benders decomposition-based methodology is developed and further enhanced with Pareto-optimal cuts and two variable fixing techniques. Computational experiments compare the effectiveness of the proposed solution algorithm against a commercial solver and provide insights into the factors influencing these decisions. The third problem addresses demand uncertainty in the hub arc location problem, integrated with decisions on shipment consolidation and inventory holding. The aim is to minimize total expected costs of infrastructure, transportation, and inventory, modelling the problem as a two-stage stochastic program. The first-stage decisions involve selecting hub arcs and determining the types and frequencies of vehicles. In the second stage, nodes are assigned to hub arcs, and decisions are made on inventory holding and the optimal routing of flows. To solve this, a Sample Average Approximation methodology is employed. Computational experiments assess the algorithm’s convergence, explore the impact of varying costs and frequencies, and estimate the value of considering uncertainty on the decision-making process.
Urban Justice in a Changing Climate: Rethinking Equity and Justice Criteria to Assess Climate Action Planning in Canadian Municipalities
(University of Waterloo, 2024-12-19) Swanson, Kayleigh
As climate change accelerates, communities around the world are forced to confront the risks and opportunities that arise from climate disruption. Socially and economically marginalized groups are particularly vulnerable, facing the greatest impact and the risk of being further disadvantaged by poorly designed climate change policies that fortify longstanding disparities. Climate action plans are rapidly being developed across governance scales to promote ambitious climate action and progressive social reform, but progress to date has focused more on addressing environmental goals than ensuring social equity. Key challenges include addressing the differential impacts of climate change on vulnerable groups, capturing the needs and priorities of underserved communities in climate change plans, and identifying concrete actions dedicated to advancing the fair distribution of environmental benefits and burdens. This dissertation considers the nature of equitable climate action planning by exploring the plan content and process conditions that are required to advance socially just planning responses to climate change. The analysis is based on three key contributions: 1) an exploration and comparison of scholarly and equity-deserving perspectives regarding the meaning of social equity and climate justice; 2) an analysis and comparison of equity-related needs and priorities across cities with diverse demographics, policy environments, and social climates; and 3) an evaluation of the equity and justice orientation of a sample of municipal climate action plans. The dissertation builds an argument that current approaches to climate action planning in Canadian municipalities generally remain unresponsive to the needs and priorities of underserved communities. Key concerns include prioritizing environmental and economic imperatives relative to social equity goals, the tendency to overlook underlying drivers of inequity, the framing of equity as an incidental and ancillary benefit of climate action, and the disconnect between commitments to social justice and planned climate actions. The dissertation draws on diverse perspectives on environmental equity, climate justice, and community engagement to recommend tangible actions that could be taken by municipal planners and policymakers to strengthen the equity orientation of their climate action planning efforts.
An Architecture for Social Participation
(University of Waterloo, 2024-12-19) Zheng, Ling Yi
A large and growing number of Canadian seniors are socially isolated. People’s appetite for group activities remains unfulfilled due to a lack of convenient and compelling opportunity. Introducing small-scale, locally relevant gathering places within existing neighbourhoods would support seniors aging in place and contribute toward an age-friendly community. Research into Ray Oldenburg’s concept of third place informs the creation of a best practices guide for the design of local destinations for social participation. The guide is then referenced for my design proposal of a gathering place in my Toronto neighbourhood.
Neck Injury Risk in Non-Neutral Position Rear Impact Scenarios Using a Reference Geometry-Based Repositioning
(University of Waterloo, 2024-12-19) Seif Reis, Matheus
Rear-end vehicle collisions may lead to whiplash-associated disorders (WADs), comprising a variety of neck and head pain responses. The source of WADs is an active area of research, but the facet joints, cervical spine ligaments, neck muscles, nerve roots, vertebral arteries, and intervertebral discs have been postulated to be potential injury sources. While most investigations focus on whiplash injuries in neutral position impacts, front-seat vehicle occupants tend to spend a significant amount of time outside the neutral axial head position. Multiple cervical tissues can experience increased mechanical loads and, consequently, higher injury risks during head-rotated impacts. Given the limited experimental data for non-neutral position rear impacts, computational human body models (HBMs) can inform the potential for tissue-level injury. Previous studies have considered external boundary conditions to reposition the head axially but were limited in reproducing a biofidelic movement for a detailed finite element (FE) head and neck model. The objectives of this study were to implement a novel head repositioning method using soft tissue stress initialization to achieve targeted axial head rotations, validate the model intervertebral motion against experimental data, and simulate neutral and non-neutral rear impacts to assess the model tissue-level response and quantify the injury risk. The head and neck model was extracted from the detailed commercial Global Human Body Models Consortium (GHBMC) M50-O FE model, representing a 50th percentile male occupant. The repositioning used a novel method to achieve equilibrium in the target axial rotations of 24.5°, 33.5°, 42.5°, 51.5°, and 60.5°, by pre-stretching the neck soft tissues. The head-rotated models underwent verification tests to ensure the target positions and equilibrium were achieved, and the method was validated by comparing spinal rotations to experimental results. A neutral position and five head-rotated models were evaluated at three rear impact severities (4g, 7g, and 10g) with and without muscle activation. Head motion, ligament distractions, muscle strains, nerve root compressions, and annulus fibrosus (AF) strains were assessed and compared with physiological limits to estimate the injury risks. The repositioning method was able to rotate the head to the five target positions, showing general agreement with reported intervertebral rotations. Under the rear impact scenarios, higher axial head rotations increased the combined three-plane rotations experienced by the head. Increasing head rotations led to higher ligament distractions and muscle strains during rear impacts, increasing their potential for injury. The trends for AF strains varied depending on the muscle activation, with peak strains being observed for initial rotations of 0° and 60.5° without muscle contraction and only for 0° with muscle contraction. Overall, muscle activation decreased ligament displacements, muscle strains, and AF strains, while higher impact severity increased the injury risk for these same tissues. Nerve root compression was minimally affected by head rotation, muscle activation, and impact severity. The models predicted injury potential for the ligaments and muscles starting at a 4g rear impact acceleration and for the AF starting at 7g, particularly under high head rotations. Therefore, the proposed repositioning method introduced in this study enabled the model to achieve steady head rotations with realistic cervical spine movements, increasing the biofidelity of non-neutral rear impact simulations. The tissue-level assessment revealed the effect of varying head rotations, muscle activation, and impact severities on cervical tissues, allowing for a comprehensive estimation of injury thresholds across ligaments, muscles, nerve roots, and AFs. The results of this study can be applied to future assessments and design of head restraints and protection systems.
Optimization-based Haptic Feedback Synthesis in Human-Multi-Robot Systems
(University of Waterloo, 2024-12-18) Anjum, Ramisha
This thesis presents an optimization-based control framework for multi-robot systems interacting with human. This framework is amenable for both centralized and decentralized control strategies, and addresses human-robot interaction as well as multi-task allocation and execution. The novelty of the framework lies in its ability to leverage optimization algorithms to manage task allocation while ensuring system passivity, which is critical to maintaining stability and safe interaction between robots and human operators. Both single-integrator and double-integrator robot dynamic models are explored for different control scenarios. While the single-integrator scenario employs decentralized control, ensuring scalability and efficient task execution, the double-integrator scenario typically utilizes centralized control. However, if human-robot interaction constraints are distributed between robots, a decentralized approach can be formulated, allowing flexible control structures. Experimental results demonstrate the system’s ability to dynamically allocate tasks, execute them efficiently, and provide haptic feedback to human operators. The human-robot interaction mechanism combines passivity-based control with feedback synthesis, ensuring that the system can adapt to real-time changes in human input while maintaining stability and safety. Additionally, the thesis identifies the limitations of a purely centralized approach, particularly in larger robot teams, and suggests future improvements, including enhanced scalability, improved feedback mechanisms, and adaptations for dynamic real-world environments. This research advances the field of human-robot collaboration by offering a robust, adaptable framework capable of handling complex multi-task scenarios. The framework is particularly suited for applications in dynamic and interactive settings, such as telerobotics, industrial automation, and other collaborative operations where human oversight and real-time control play a crucial role.
Measurements of water isotope composition and depth variation reveal strong influence of hydroclimate on water balance and water levels of shallow lakes in the Peace-Athabasca Delta (northern Alberta, Canada)
(University of Waterloo, 2024-12-18) Imran, Arisha
Shallow water bodies are abundant, productive ecosystems in northern high-latitude regions where they provide habitat for fauna and hold socio-economic and cultural importance for remote communities. In northeastern Alberta, the Peace-Athabasca Delta (PAD), located within Wood Buffalo National Park (WBNP), is a large (~6000 km2) inland freshwater-rich landscape with an abundance of shallow lakes that is listed as a Ramsar Wetland of International Importance and contributes to WBNP’s UNESCO World Heritage status. However, concerns have long persisted about the effects of primarily hydroelectric regulation of Peace River flow and climate change on widespread drawdown of lake water-levels in the delta. In response to these concerns, and pressures from local communities and an international agency, a federal Action Plan was developed with goals to improve aquatic ecosystem monitoring at the PAD. Despite considerable prior study, this requires better understanding of hydrological processes that influence lake water balances and water levels in the delta and advancement of methodological approaches. A 7-year research project was launched in 2015 to inform the design of a long-term aquatic ecosystem monitoring program at the PAD. Research presented in this thesis is an outcome of two key observations that were made during the last two years (2020-2021) of that project, which provided opportunity to explore the influence of unusually high relative humidity on isotope-based lake water-balance modelling and the influence of snowmelt runoff on lake depth when widespread ice-jam flooding occurred. For two decades, the isotope composition of an index lake (informally named ‘PAD 18’) provided a constant and reliable estimate of δSSL (i.e., the water isotope composition of a terminal basin where evaporation = inflow), a key parameter used in an isotope framework for water-balance modelling of lakes at the PAD. In 2020-2021, a sudden and unprecedented shift occurred in the isotope composition of PAD 18, which required closer examination of the isotope framework to ensure accurate assessments of lake water balances. The shift in isotope composition of PAD 18 coincided with an increase in relative humidity by 4.6% from 66.2% (2015-2019) to 70.8% (2020-2021). An independent calculation of δSSL, using formulation by Gonfiantini (1986) and flux-weighted air temperature and relative humidity from 2020-2021, was determined to be equivalent to the observed isotope composition of PAD 18 during 2020-2021, confirming the shift in isotope composition reflected re-equilibration of the lake water with the atmosphere following the rise in relative humidity. The importance of accurate characterization of δSSL for isotope mass-balance modelling is demonstrated by estimating evaporation-to-inflow (E/I) ratios for 61 lakes across the PAD in July 2021 using the previous 2015-2019 isotope framework and the new 2020-2021 isotope framework. Results show differences between the two frameworks are minor when E/I ratios are low, but they become consequential when E/I ratios are high because of the non-linear effect of relative humidity on isotope framework parameters. Appropriate parametrization for isotope mass-balance modelling is critical for monitoring agencies utilizing isotope-based techniques at the PAD, and elsewhere. Thus, re-evaluation of isotope framework parameters may become increasingly important as climate warming fosters greater variability of meteorological conditions. Snowmelt runoff is well-recognized for sustaining shallow waterbodies across semi-arid and sub-humid northern regions where evaporation rates are high. At the PAD, however, the influence of snowmelt runoff from within the delta remains largely unknown because the attention on drawdown of perched lakes has focused almost exclusively on alteration of the ice-jam flood regime. During spring of 2020, extensive ice-jam flooding occurred which raised water levels in flooded lakes across the PAD, but water levels rose also in many non-flooded lakes, providing an opportunity to explore the role of snowmelt runoff on lake levels. Using measurements of water depth and water isotope compositions, the contributions from snowmelt runoff and river floodwaters to lake-level rise were quantified at 52 lakes and spatial patterns were explored. Results reveal that the lake-level rise from snowmelt runoff at non-flooded lakes rivals the rise caused by floodwaters at flooded lakes. Geospatial analyses show lake-level rise by snowmelt was greatest in the northern Peace sector and the southwestern margin in the southern Athabasca sector where greater topographic relief and denser vegetation enhance snow accumulation via redistribution of snow by wind from adjacent flat, sparsely vegetated terrain. In contrast, the rise due to floodwater input was greatest in lower lying flood-prone central areas of the Athabasca sector. Exploration of meteorological records since 1963 reveal that similar contributions of snowmelt runoff to lake-level rise as occurred in 2020 were likely common between the early 1960s and late 1980s but only once since 1987 (2018), suggesting that reduced input from snowmelt runoff has contributed to drawdown of shallow perched lakes in recent decades. Concern for drawdown of water levels in the PAD have prompted a need for enhanced monitoring of lake water balances and water levels, especially as mitigative actions are considered. The research presented in this thesis advances knowledge about the influence of shifts in relative humidity on isotope-based modelling of lake water balances and the role of snowmelt runoff on lake depth. The novel integration of water isotope composition and water depth measurements demonstrated here provides opportunity for assessing the success of mitigative actions such as strategic water releases from the W.A.C. Bennett Dam located upstream of the delta to enhance ice-jam flooding. While long-term aquatic ecosystem monitoring programs must be built on a foundation of knowledge generated through primary research, systematic and repeated measurements over sufficient scales of space and time may also trigger new research that leads to important new discoveries, as revealed in this thesis.
Diffusion Of Technology in Vulnerable Communities: An Analysis of the Role of Technology in Making Small-Scale Fisheries Viable
(University of Waterloo, 2024-12-18) Yousaf, Muhammad Tahir bin
This thesis investigates the diffusion of technology in small-scale fisheries (SSFs), focusing on how technological innovations can enhance their sustainability and viability, particularly within marginalized communities. SSFs play a vital role in global food security and livelihoods, yet they face significant challenges such as limited market access, environmental degradation, and overfishing. The research explores the diffusion of key technologies, including GPS monitoring devices, smartphone applications, and real-time monitoring systems, which hold the potential to improve resource management, operational efficiency, and market connectivity in SSFs. The study is framed within theoretical models like Rogers' Diffusion of Innovations Theory, the Technology Acceptance Model (TAM), and Innovation Diffusion Theory (IDT), offering a comprehensive analysis of how these technologies spread within vulnerable SSF communities. Case studies from Southeast Asia, Latin America, the Philippines, Timor-Leste and Africa illustrate both the successful diffusion of technologies and the challenges encountered, such as financial barriers, lack of technical capacity, cultural resistance, and inadequate institutional support. The thesis highlights that the successful diffusion of technology depends not only on the innovations themselves but also on factors like community participation, tailored training programs, access to financial resources, and supportive governance frameworks. The study concludes that while technological diffusion can transform SSFs operations by improving sustainability and resilience, overcoming socio-economic and infrastructural challenges is crucial. This research provides a nuanced understanding of technology diffusion in SSFs and offers practical insights for policymakers and stakeholders seeking to promote sustainable fisheries through technological innovation.
The Role of the Laminar Separation Bubble in Wind Turbine Aeroacoustics and Dynamic Stall
(University of Waterloo, 2024-12-18) Zilstra, Alison
The implementation of airfoils in low Reynolds number (Re) conditions requires careful consideration of the natural boundary layer (BL) transition as it covers a significant portion of the airfoil surface and often includes the formation of a laminar separation bubble (LSB). This study focuses on the role of the LSB in two design challenges facing low Re applications including small wind turbines (SWT): the generation of tonal airfoil self-noise and the blade loading fluctuations that occur during dynamic stall. Computational fluid dynamic (CFD) and computational aeroacoustic (CAA) methods were applied to two low Re airfoils to first validate the ability of the chosen methods to predict the complex LSB behaviour and second investigate the role of the LSB in these processes. Multiple detailed experimental data sets were combined to form a comprehensive validation of the simulated aerodynamic and aeroacoustic behaviours. The investigation of tonal airfoil self-noise was completed using the SD 7037 airfoil at a modest Re of 4.1x10⁴. The numerical methods of incompressible wall-resolved large eddy simulation (LES) and the Ffowcs-Williams and Hawkings (FW-H) acoustic analogy correctly predicted the tonal aeroacoustic noise and the Kelvin-Helmholtz (K-H) rolls that form in the LSB were identified as the acoustic source. Analysis of the transient BL development showed that the K-H rolls were amplified through a LSB pressure feedback process that altered the development of the laminar BL upstream of the LSB. Later, the analysis of the deep dynamic stall process was completed using unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations of the SD 7037 airfoil at Re=4.1x10⁴ and a pitching reduced frequency of k=0.08, and the S833 airfoil at Re=1.7x10⁵ and k=0.06. The simulated timing of the dynamic stall agreed with experimental data for both airfoils which is an advancement from the early prediction of stall seen consistently in previous numerical studies. The accurate prediction of dynamic stall was found to be dependent on the correct simulation of the bursting of the LSB, which initiated the complete separation of the boundary layer and the formation of a leading edge vortex. The airfoil self-noise and dynamic stall simulations both proved the important role the LSB plays in these behaviours for low Re airfoils. All simulation methods also required strict grid refinement at the leading edge of the airfoil to correctly develop the transient BL transition behaviours for the tonal noise prediction and to capture the bursting of the LSB in the dynamic stall simulations. Grid refinements offset from the airfoil surface were also required to capture the BL transition that occurs in the separated region of the LSB. The successful application of LES and FW-H for tonal noise prediction and URANS for dynamic stall prediction opens the possibility of incorporating these methods into the aerodynamic and aeroacoustic design of airfoils for low Re applications including SWTs.
Echoes of Exploitation: Tracing the Impact of Racial Capitalism in Birmingham’s Titusville Neighbourhood
(University of Waterloo, 2024-12-18) Brown, Brianna Nicole St Clair
This thesis examines the exclusionary planning practices that shaped the urban fabric of the United States through segregation, focusing on the Titusville neighbourhood of Birmingham, Alabama, as an illustrative example. The work highlights how cycles of capitalist oppression adapt and persist, perpetuating socioeconomic disparities among African American residents in pursuit of excess wealth. It investigates how exploitative mechanisms – such as organized abandonment, predatory inclusion, and organized violence – are reiterated and reinforced by municipal and federal policies, continuously restructuring regimes of accumulation to enshrine inequality. Through this theoretical framework, the research examines the history of Birmingham from its incorporation during the 19th century to its current state in the 21st century. The transformative theory of reparative planning provides parameters for dismantling exploitative capitalist structures. While the city’s efforts through the Titusville Community Framework Plan are a start, a lack of accountability and implementation has shifted the burden onto nonprofit community groups in the area. Insights gathered from interviews with leaders of two contrasting nonprofit organizations, the Titusville Development Corporation and the Dynamite Hill-Smithfield Community Land Trust, highlight the need for a multi-faceted approach to reparative planning. In the pursuit of anti-racist futures, combining pragmatic and transformative strategies is essential for dismantling the legacy of exclusionary planning. This study seeks to uncover the historical and ongoing impacts of these oppressive structures and advocate for reparative planning that genuinely addresses the needs of the Titusville community and, consequently, the larger American context.
Nurturing Ease: A Holistic Design Approach for Hospices in Ontario
(University of Waterloo, 2024-12-18) Pereira, Olivia
We all encounter death in life. For those facing terminal illness, having agency to prepare for the end-of-life or the loss of a loved one is a deeply personal and profound experience. Hospice aims to provide a comforting and peaceful environment for individuals and their loved ones during this final phase of life, an alternative to the home or hospital. This thesis focuses on establishing a holistic approach to hospice design, building upon existing compassionate architecture and evidence-based practices to prioritize human experience and create opportunities for meaningful moments of connection - with oneself, loved ones, and community. This thesis integrates literature reviews, case studies, and fieldwork conducted in the Region of Waterloo to inform the architectural brief and kit of parts that shape the design proposal. Literature reviews on biophilic design and evidence-based design considerations for care environments, and case studies of hospice and adjacent residential-healthcare typologies in an international context serve as a basis for approaching hospice design. This is further contextualized to Ontario through an architectural catalogue of hospices across the province and fieldwork insights from care providers and staff of hospices in the Region of Waterloo, offering perspectives beyond what is prescribed in the current design standards informing hospice design in the province. Ultimately, this thesis seeks to define a holistic design approach for hospice residences in Ontario, one that prioritizes human experience and contributes to the growing body of international research on hospice architecture. Through this, it establishes a practical design guide that enriches the spatial requirements for future hospices in the province, fostering environments where the final moments of life are supported with sensitivity and compassion.
Dynamic Offices: Workplace Design For Individual Autonomy
(University of Waterloo, 2024-12-18) Lee, Ernest
The hybrid work model, whereby workers divider their time between working remotely and in the office, has become more prevalent through recent years, largely accelerated by the COVID-19 pandemic. In contrast to the conventional way of working where all employees come into the office everyday, employees have more flexibility in their schedule on how, when, and where they want to work enabling them to optimize their productivity. Reducing the number of staff in the office when implementing the hybrid office approach can result in under-utilized spaces as the office infrastructure remains designed to accommodate a larger workforce. As a result, there is an opportunity for businesses to work in a smaller office footprint, reducing the number of supporting spaces and enabling them to be repurposed for highly collaborative program. Furthermore, a hot desk system—where employees share and use any available workstation—can be implemented to optimize space utilization. However, the implementation of hot desks leads to a disconnect between the user and the workspace. Staff members will not arrive to the office to use the same personal desk every time. The lack of consistency requires employees to adapt to spaces that are available on a given day. As the space is shared, occupants lose control of their environment and become unable to customize it according to their preferences. This thesis explores how a shared workplace can be designed to make use of the efficiencies of the hot desk model as implemented in response to a hybrid work environment while allowing the space to feel personal and familiar by leveraging qualities from design that is both flexible and adaptable. The exploration is carried out through design exercises exploring three scales of intervention. An existing building is selected and reimagined to accommodate multiple tenants operating on hybrid schedules with attention to space optimization and shared programming. At the intermediate scale, a modular system-based approach to floorplan layouts is introduced, allowing the space to be reconfigured while maintaining design cohesion and accommodate constant changes occurring within an organization. At the smallest scale, a workstation with automated reconfigurable elements is designed to provide familiarity and personalization within a hot desk system approach. These interventions are unified through a carefully balanced integration of technology that enhances user experience while providing valuable insight into how the space is performing. These interventions extend beyond the scope of efficiency; it improves the experience of those working in the space which leads to enhanced productivity, collaboration, and a stimulating working environment.
Adversarial Black-Box Testing of Self-Driving Vehicle Algorithms with Reinforcement Learning
(University of Waterloo, 2024-12-17) Nahorna, Oleksandra
When we hear autonomous or ego vehicles, we imagine a safe, self-driving device. However, this designation is unsuitable for describing a self-driving car because the car's automation is still being refined, and safety is being studied and constantly improved. Right now, we can observe mostly the vehicles that are not fully autonomous to be present on the road in the physical world. The autonomy introduced requires the driver to be able to switch and take control of the vehicle in the case of an emergency occurrence. On the contrary, for the car to be able to apply full autonomy and be recognized and approved by the government to be placed on the road, the vehicle algorithm should be able to resolve and predict cases that may occur on the road and be able to respond to the situation utilizing the decision-making approach. The physical world setting may be constrained in terms of stress-testing the ego-vehicle before its availability to the regular user-driver. Therefore, to broaden the ability to stress-test autonomous vehicles in various scenarios, the manufacturer of the autonomous vehicle and its algorithm may benefit from utilizing the ability to stress-test vehicles in the virtual vehicle setting. For the work presented instead of enhancing the ability of safety enhancement of the autonomous vehicle by training it as a white box using the algorithm exposed by the manufacturer - we are introducing the adversarial virtual environment setting with generated accidents by the algorithm for the provider/manufacturer of the autonomous vehicle and its algorithm to be stress-tested in a black-box approach without the exposure of the technology (ego-vehicle algorithm) by the manufacturer. Using the Reinforcement Learning technique, a single-agent or multi-agent attacker vehicle is trained to reproduce collisions in a virtual environment. The cases generated can be different, both simple and difficult to mimic a real-world setting. When we describe autonomous vehicle adversarial blackbox testing, we identify the target vehicle as a representation of the autonomous vehicle by determining the action space, kinematics, and behaviour of the vehicle mentioned as autonomous throughout the work. This vehicle representation mimics the autonomous vehicle approach/action/decision-making within the 2D setting of the chosen virtual environment, with constraints driven by the virtual environment. This work challenges realism, namely, it compares the likelihood of emergencies in generated car accidents to real-life cases. To do this, as in any other area, we study historical data on road accidents. These situations are compared with selectively generated instances, and a successful comparison is recorded and described by creating a narrative for the generated situation. Thereby smoothing the boundary between virtual and real accidents on the road. It is important to note that reproducing and preparing ego-vehicle for any situations that may arise on the road in a virtual environment can be an economical approach. After all, to train the model, only time is needed depending on the number of generated episodes, thereby reducing the cost of testing or pre-testing. And it will also help to recreate scenarios that are problematic for recreation in real, physical space. Testing cars using different algorithms can help to identify a pattern or algorithm suitable for a specific environment, type of road, and number of actors on the road. This work seeks to publicize and recommend using a virtual environment to improve the automotive industry.

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