Graduate Theses & Dissertations

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Time Series Algorithms in Machine Learning - A Graph Approach to Multivariate Forecasting
Forecasting future values of time series has long been a field with many and varied applications, from climate and weather forecasting to stock prediction and economic planning to the control of industrial processes. Many of these problems involve not only a single time series but many simultaneous series which may influence each other. This thesis provides methods based on machine learning of handling such problems. We first consider single time series with both single and multiple features. We review the algorithms and unique challenges involved in applying machine learning to time series. Many machine learning algorithms when used for regression are designed to produce a single output value for each timestamp of interest with no measure of confidence; however, evaluating the uncertainty of the predictions is an important component for practical forecasting. We therefore discuss methods of constructing uncertainty estimates in the form of prediction intervals for each prediction. Stability over long time horizons is also a concern for these algorithms as recursion is a common method used to generate predictions over long time intervals. To address this, we present methods of maintaining stability in the forecast even over large time horizons. These methods are applied to an electricity forecasting problem where we demonstrate the effectiveness for support vector machines, neural networks and gradient boosted trees. We next consider spatiotemporal problems, which consist of multiple interlinked time series, each of which may contain multiple features. We represent these problems using graphs, allowing us to learn relationships using graph neural networks. Existing methods of doing this generally make use of separate time and spatial (graph) layers, or simply replace operations in temporal layers with graph operations. We show that these approaches have difficulty learning relationships that contain time lags of several time steps. To address this, we propose a new layer inspired by the long-short term memory (LSTM) recurrent neural network which adds a distinct memory state dedicated to learning graph relationships while keeping the original memory state. This allows the model to consider temporally distant events at other nodes without affecting its ability to model long-term relationships at a single node. We show that this model is capable of learning the long-term patterns that existing models struggle with. We then apply this model to a number of real-world bike-share and traffic datasets where we observe improved performance when compared to other models with similar numbers of parameters. Author Keywords: forecasting, graph neural network, LSTM, machine learning, neural network, time series
Assessing the Cost of Reproduction between Male and Female Sex Functions in Hermaphroditic Plants
The cost of reproduction refers to the use of resources for the production of offspring that decreases the availability of resources for future reproductive events and other biological processes. Models of sex-allocation provide insights into optimal patterns of resource investment in male and female sex functions and have been extended to include other components of the life history, enabling assessment of the costs of reproduction. These models have shown that, in general, costs of reproduction through female function should usually exceed costs through male function. However, those previous models only considered allocations from a single pool of shared resources. Recent studies have indicated that the type of resource currency can differ for female and male sex functions, and that this might affect costs of reproduction via effects on other components of the life history. Using multiple invasibility analysis, this study examined resource allocation to male and female sex functions, while simultaneously considering allocations to survival and growth. Allocation patterns were modelled using both shared and separate resource pools. Under shared resources, allocation patterns to male and female sex function followed the results of earlier models. When resource pools were separate, however, allocations to male function often exceeded allocations to female function, even if fitness gains increased less strongly with investment in male function than with investment in female function. These results demonstrate that the costs of reproduction are affected by (1) the types of resources needed for reproduction via female or male function and (2) via trade-offs with other components of the life history. Future studies of the costs of reproduction should examine whether allocations to reproduction via female versus male function usually entail the use of different types of resources. Author Keywords: Cost of Reproduction, Gain Curve, Life History, Resource Allocation Patterns, Resource Currencies
History and Legacy of the “Orillia Asylum for Idiots
The “Orillia Asylum for Idiots” (1861 - 2009), Canada’s oldest and largest facility for the care and protection of children and adults with disabilities, was once praised as a beacon of humanitarian progress and described as a “community within a community.” Yet, survivors who lived in the facility during the post Second World War period, a time described as the “golden age of children’s rights,” tell harrowing stories of abuse and neglect. Despite the nation’s promise to “put children first” and protect the universal rights of “Canada’s children,” children incarcerated within the Orillia Asylum were subjected to systemic neglect and cultural discrimination, daily humiliation and dehumanization, and physical, sexual, and emotional abuse. Far from being a place for child protection and care, this dissertation finds that the Orillia Asylum was a site of a multi-faceted and all-encompassing violence, a reality that stands in complete contrast to the grand narrative through which the facility has historically been understood. This dissertation considers how such violence against children could occur for so long in a facility maintained by the state, a state invested in protecting children. It finds that children who were admitted to the Orillia Asylum were not considered to be “Canada’s children” at all by virtue of being labelled as “mentally deficient,” “feeble-minded,” “not-quite-human,” and “not-quite-children.” Author Keywords: childhood, disability, Huronia Regional Centre, institutional child abuse, institutional violence, institutionalization
Shoreline Stewardship
This thesis aimed to determine what factors influence individual- and community-level shoreline stewardship attitudes and behaviours. Shoreline stewardship is part of the broader literature of environmental stewardship and place-based conservation. The needs and barriers limiting stewardship action were examined, as were the opportunities for increased impact. The Love Your Lake (LYL) program served as a case study into the impact of ENGO programming on shoreline stewardship among shoreline property owners in Ontario. This was investigated using a program workshop, interviews and focus groups with past program participants, and existing participant survey data. Community-Based Social Marketing principles were used to further examine the opportunities for increased impact on stewardship behaviour. The study found that the LYL program was effective in starting or continuing a conversation in communities around shoreline health. Some of the remaining needs and/or barriers included limited time at the cottage; limited knowledge of how to fix existing shoreline issues; low stock of local native plants and environmentally minded landscapers; ineffective messaging; a lack of interest, enthusiasm or concern; and weak environmental policies and governance of shorelines. Some participants also listed cost as a barrier, while others felt it had been well addressed already. Most participants thought that education could be a barrier but that it had been well addressed locally through LYL or other programming. Some key motivators and opportunities to increase shoreline stewardship included community building, increased lake association capacity, improved communication and marketing strategies, and persistence. Author Keywords: Community-Based Social Marketing, Environmental Stewardship, Lake Health, Place-Based Conservation, Pro-Environmental Behaviour, Shoreline Stewardship
Perspectives on Poultry
The contemporary denigration of poultry combined with the intensification of industrialized animal agriculture has deepened divides between humans and poultry, creating a disconnect that holds implications for both parties and the sustainability of North American food systems. This study explores how people with poultry keeping experience perceive these animals, how their views are influenced and how these narratives may intersect with themes of sustainability. Surveys and interviews aimed at small flock keepers and commercial farmers within an area of Central Ontario revealed that poultry sentience was widely recognized among participants. Overall, this study’s findings disrupt commonly held notions that poultry are one-dimensional beings and highlight the mutual benefits that can come when the distance is lessened between humans and poultry. This research contends that reimagining human-poultry relationships could improve our ability to consider and challenge dominant systems that perpetuates unsustainable food production and negatively affects both animal and human life. Author Keywords: history poultry keeping, human-animal studies, human-poultry relationships, keeper attitudes, poultry sentience, sustainable food systems
Extraction and Characterization of Hyaluronic Acid and Collagen from Eggshell Membrane Waste
Connecting academia to industry is one important way to advance towards meeting the United Nations (UN) Sustainability Goals (SDGs).1 Sustainability can be applied to all industrial sectors with the SDGs being implemented by 2030.2 This research contributes to the SDGs by investigating a way to remediate an industrial waste stream in the egg-breaking industry. If adopted, this would reduce the amount of eggshell membrane (ESM) waste placed in landfill where it does not decompose properly. The work described in this thesis specifically targets extraction of collagen and hyaluronic acid (HA), two components of the ESM that are of commercial value in the cosmetic, pharmaceutical, and biomedical industries3,4 . Deliverables from this research include economically viable extraction methods, developed based on green chemistry approaches, that can be transferred from lab bench to industrial scale. The extraction development process was guided by the 12 Principles of Green Chemistry5,6,7 and the 12 Principles of Green Engineering.8 HA was most successfully extracted using a sodium acetate solution on ground ESM. Filtrate was collected, exhaustively dialyzed and lyophilized. High molecular weight HA was recovered. Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy and proton nuclear magnetic resonance (NMR) spectroscopy compared extracted material to reference HA identifying successful extraction. Collagen was extracted using acetic acid or pepsin enzyme digestion. Hydrophilic interaction liquid chromatography (HILIC) coupled with mass spectrometry (MS) compared amino acid composition of extracted materials to reference collagen material. FTIR-ATR spectra also supported successful extraction of collagen. This work identifies that HA and collagen can be conveniently extracted from ESM using an economical approach that can be implemented into egg-breaking facilities. This work highlights the benefits of connecting academia to industry to advance green chemical approaches while implementing sustainable practices into existing industry. Author Keywords: collagen, eggshell membrane waste, extraction, green chemistry, hyaluronic acid, sustainability
Finding Cowboy Joe
Canadian authored diverse LGBTQ2S children's picture books can help counter socialized aspects of heteronormativity and other forms of oppression. This thesis outlines the challenging process for identifying and locating Canadian authored diverse LGBTQ2S children's picture books, with suggestions provided for mitigating this process. Twenty-two books (list and summaries included) are collected and then analysed through three different lenses: Sipe’s Semiotically Framed Theory of Text-pictured Relationships; intersectionality; and Canadian Studies. Findings include: the significance of a micro press in offering representation for queer intersectionality, the shift from the portrayal of discrimination against queer parents to an attention to the policing of children’s gender identity and expression, and the embrace of the child on their own terms. In addition, a Canadian queer children’s book has been created by the researcher, developed through the process of writing of this thesis. Author Keywords: Canadian authors, Canadian identity, children’s picture books, countering heteronormativity, ethnic diversity, LGBTQ2S
(Re)encountering black bears
This thesis explores the perceptions of human-bear interactions in Ontario, suggesting that they have been shaped by narratives that have roots in colonial perceptions of nonhuman animals. Further, I seek to consider how these interactions could unfold differently if we rethought our relationships and responsibilities to these beings, in particular through an embrace of Indigenous-led conservation informed by ideas of animal welfare. The methods used for this research were first empirical, through qualitative data collection via interviews. Second, it was interpretive, through the observation of bear experiences and through the analysis of circulated and conceptual themes of bear information found in media articles. What emerged was an understanding that the mitigation efforts which are used when human-bear interactions occur are deeply influenced by political, social, and cultural factors that cannot be removed from these matters, asserting that a reconceptualization of current conservation frameworks needs to be considered. Author Keywords: Compassionate conservation, Human-bear interactions, Human-wildlife relations, Indigenous conservation, Narrative inquiry, Wildlife conservation
Adoption of a Finite Element Model of Material Deformation Relevant to Studying Corneal Biomechanics
The human cornea is required to exhibit specific material properties to maintain its regular shape under typical intraocular pressures which then allow for its correct optical functionality. In this thesis, the basis of continuum solid mechanics and the finite element method are introduced. We use finite element modelling to simulate the extension of an effective-1d, linear-elastic bar, a cornea-like body governed by Poisson’s equation, and the deformation of a loaded, linear-elastic, cube. Preliminary results for the deformation of a simulated, linear-elastic, cornea have also been achieved using the finite element approach. Author Keywords: continuum solid mechanics, corneal biomechanics, finite element method, intraocular pressure
Through the eyes of the Ontario farmer
Dairy goat farming has become increasingly popular in recent years in Ontario. This qualitative study done by semi-structured interviews, examines the why and the wherefore of the opinions held by dairy goat farmers in Ontario in regards to sustainable agriculture. It was found that these farmers feel that sustainable agriculture is important. These farmers believed their farms to be sustainable and have implemented sustainable farming practices that reflect these interests. Their primary interest is to maintain their farmland for the use of future generations as well as maintaining the economic and environmental sustainability of their farms. There is currently a lack of scientific information available for dairy goat farmers in Ontario. Challenges presented by the participants should be researched so as to better serve this budding industry which may become one of the most sustainable livestock industries in Ontario. Author Keywords: agriculture, dairy goat, farmer opinion, farming, sustainability, sustainable agriculture
Modelling Depressive Symptoms in Emerging Adulthood
Depression during the transition into adulthood is a growing mental health concern, with overwhelming evidence linking the developmental risk for depressive symptoms with maternal depression. In addition, there is a lack of research on the protective role of socioemotional competencies in this context. This study examines independent and joint effects of maternal depression and trait emotional intelligence (TEI) on the longitudinal trajectory of depressive symptoms during emerging adulthood. A series of latent growth models was applied to three biennial cycles of data from a nationally representative sample (N=933) from the Canadian National Longitudinal Survey of Children and Youth. We assessed the trajectory of self-reported depressive symptoms from age 20 to 24 years, as well as whether it was moderated by maternal depression at age 10 to 11 and TEI at age 20, separately by gender. The results indicated that mean levels of depression declined during the emerging adulthood in females, but remained relatively stable in males. Maternal depressive symptoms significantly positively predicted depressive symptoms across the entire emerging adulthood in females, but only at age 20-21 for males. In addition, likelihood of developing depressive symptoms was attenuated by higher global TEI in both females and males, and additionally by higher interpersonal skills in males. Our findings suggest that interventions for depressive symptoms in emerging adulthood should consider development of socioemotional competencies. Author Keywords: Depression, Depressive Symptoms, Emerging Adulthood, Intergenerational Risk, Longitudinal, Trait Emotional Intelligence
Radiocarbon Analysis of the Middle to Late Woodland Transition in Southern Ontario
The goal of the thesis is to establish the temporal patterning of the cultural complexes of the Middle to Late Woodland periods in Ontario. To do so I examine the statistical shape and phase boundaries of samples of radiocarbon dates associated with the Princess Point, Sandbanks, Glen Meyer, and Pickering archaeological complexes. The radiocarbon dates used for this thesis were collected through published sources, grey literature, and resources such as the Canadian Archaeological Radiocarbon Database. Each date was put through a data hygiene process and those deemed acceptable were merged into Summed Probability Distributions (SPDs) and further analysed through the r-carbon and OxCal packages. Bayesian statistics were used to estimate the start and end dates per complex, Shapiro-Wilks tests were used to examine the legitimacy of cultural entities, and the amount of geographic, and chronological overlap was determined by randomly sampling between the compared datasets to determine an acceptable threshold of randomness. Results indicate that the Princess Point complex does not meet the requirements of a culturally homogeneous archaeological cultural group. There is no difference in the Glen Meyer and Pickering radiocarbon patterns, which supports combining them into a single cultural designation. It was impossible to evaluate the Sandbanks complex due to a lack of radiocarbon data, although overall it seems to agree with the current understanding of the complex. Author Keywords: Glen Meyer, Ontario Archaeology, Pickering, Princess Point, Radiocarbon, Sandbanks

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Format: 2021/09/16