UVicSpace | Institutional Repository
UVicSpace is the University of Victoria’s open access scholarship and learning repository. It preserves and provides access to the digital scholarly works of UVic faculty, students, staff, and partners. Items in UVicSpace are organized into collections, each belonging to a community.
For more information about depositing items, see the Submission Guidelines.
Recent Submissions
Torsion in Chow groups of quadrics
(2025) Quigley, Khai; Scully, Stephen
We investigate here the Chow groups of arbitrary projective quadrics over a field k of characteristic 2. Much work has been done on the Chow groups of quadrics over fields of characteristic different from 2, but relatively little is known when the characteristic is 2, and even less so when the quadrics are allowed to be singular. For a smooth variety, the codimension one Chow group CH^1(X) is naturally isomorphic to the Picard group Pic(X), but this is not necessarily true when X is singular, even if X is a quadric. We therefore begin by computing Pic(X) for an arbitrary anisotropic quadric X. This allows us to generalize the well-known result stating that two nonsingular quadratic forms are similar if and only if their corresponding quadrics are isomorphic to the case of anisotropic singular forms.
One important case in characteristic not 2 in which CH(X) is fully understood is the case where X is an excellent quadric. This computation (due to Rost, Karpenko and Merkurjev) rests on two key ingredients: (i) Rost's determination of the Chow groups of affine norm quadrics, and (ii) the action of cohomological Steenrod operations on the mod-2 Chow groups of smooth varieties. For many years, (ii) was only available over fields of characteristic different from 2, but recent work of Primozic has removed the characteristic requirement. In the present work, we extend (i) to the characteristic-2 case, thereby allowing us to determine the Chow groups of all excellent quadrics in this setting. We then begin a systematic study of the torsion subgroup of CH^p(X) for an arbitrary (possibly singular) quadric X. We completely resolve the p = 1 case, and provide strong partial results for the p = 2 case.
Proactive monitoring for data drift in classification models
(2025) Isert, Zeverin; Neville, Stephen William; Darcie, Thomas Edward
This thesis introduces methods for proactively monitoring data drift in classification models, aiming to provide early warnings before significant changes occur in the prediction distribution. These “proactive alerts” allow model operators to initiate retraining processes before models enter persistent failure modes, contrasting with traditional “reactive” alerts that only trigger after observing sufficient evidence of data misclassification. The research was conducted in collaboration with Revela Systems, addressing a common industry need for robust machine learning model monitoring.
The motivation for proactive monitoring stems from significant costs and time savings associated with preventing model failures. Existing monitoring approaches often fall short, either due to test data not being representative of live data or the inherent unpredictability of live data with unknown drift. The proposed approach aims to be lightweight, scalable, and industry-deployable by making pragmatic trade-offs against academic alternatives.
The core contribution is a novel algorithm for detecting data drift in black-box classification models, focusing on understanding and tracking the model’s decision boundary. This algorithm is designed for production environments, capable of making predictions on both live and synthetic data. An incremental version of the algorithm, which does not require access to training data, can detect concept drift as it happens by querying the model. Furthermore, the thesis presents a method for synthesizing examples in high-dimensional feature spaces, crucial for mapping these decision boundaries.
The methodology centers on extracting meaning from a classifier’s decision boundary by learning how its output changes through data synthesis and live data monitoring. A classifier divides its input space into regions, with decision boundaries existing where the corresponding discriminant functions are equal. Two main approaches are explored: an eager mapping of the decision boundary in a reduced dimension and a lazy probing technique in the original feature space. Both techniques utilize a form of raycasting to determine if input data trends toward these boundaries, which implements the proactive component of the approach.
Experimental results were obtained using a custom “incident generator” tool that synthesizes infinite data streams based on the statistics of fixed-size datasets. The tool allows for real-time mutation and injection of various data drift types, including incremental, sudden, and gradual drifts. The metric for evaluating the system’s performance was the percentage of probing rays that collided with a decision boundary. Experiments showed the monitoring system’s ability to detect incremental drifts, providing early indications as data trends toward decision boundaries. While the system could react to sudden drifts, forecasting them proved challenging due to the abrupt nature of the change. Gradual drifts offered an opportunity for forecasting, though as changes are non-positional, reaction could be delayed. The experiments also highlighted frailty in ray collision percentages as a measurement and a remaining significant processing time for certain high-dimensional scenarios.
Urban Indigenous well-being and ecological restoration: Applying social-ecological systems theory through Métis relationality
(2025) Gentes, Hannah V.; Shackelford, Nancy; Corntassel, Jeff
Urbanization has detrimental impacts on ecosystems through the removal of Indigenous peoples and relationships to the land, influencing the biodiversity crisis and impacting Indigenous health and well-being. As urban populations continue to rise, so should efforts to restore and conserve urban ecosystems, led by the knowledge and wisdom of Indigenous peoples. Among these ecosystems, urban wetlands are among the most depleted, and are arguably the most important for biodiversity support, climate mitigation and adaptation, and cultural well-being. The restoration of an urban wetland at the University of Victoria provides insight into how Indigenous-led restoration in urban spaces functions as both an ecological resource offering essential ecosystem services, and a social resource for Indigenous community connection and well-being.
In this thesis, a conceptual framework was used to weave together Western Social-Ecological Systems (SES) theory and the Métis kinship law of wâhkôtowin, recognizing that effective restoration outcomes require equal engagement of both social and ecological systems. The application of nested adaptive cycles understood as panarchies, connects western and Indigenous relational concepts to understand the cross-scale social-ecological impacts of restoration. 12 semi-structured interviews were conducted with members of the Indigenous campus community at the University of Victoria in British Columbia, Canada, using the Métis law kîyokêwin as method, to understand how urbanization has impacted their relationships across social-ecological scales: to the land and waters, to their families and communities, and to themselves. Following the implementation of a restoration project in a degraded marshland at the First Peoples’ House at the University, 6 additional interviews were conducted to assess the impact of the restoration on participants' well-being. To accompany this, the health and well-being of 45 culturally significant Pacific silverweed (Potentilla anserina subsp. pacifica) plants at the marshland site were followed to assess the impact of human management on wetland plant productivity and reproductive success in urban spaces.
These assessments revealed how the reintroduction of Indigenous peoples to urban landscapes through the relationships to culturally significant plants impacted social-ecological well-being. Plants with high human interaction demonstrate significant trends in productivity and reproductive success, whereas interview participants who had high engagement with the restoration work demonstrate increases in feelings of belonging, connection, and acceptance. Together, the results of the interviews and plant trials reveal that effective restoration in highly populated urban areas requires Indigenous peoples' health and well-being to be placed at the forefront to achieve successful outcomes. Having dedicated spaces for Indigenous peoples to gather and share ecological knowledge is a political act of cultural and ecological survival. Focusing on the most marginalized communities in a system benefits everyone, with cross-scale effects that support resilient, biodiverse, and socially equitable futures in cities. Highly colonized educational institutions, such as universities, have an opportunity to influence broader societal change, thereby preventing social-ecological collapse.
Teachers' translanguaging practices and anxiety in implementation: An exploration of Iranian EFL teachers’ attitudes and perceptions
(2025) Ghashghaie Nezhad, Pegah; Huang, Li-Shih
This mixed-methods study explores Iranian English-as-a-Foreign-Language (EFL) teachers' attitudes toward translanguaging, their classroom practices, and their perceived anxiety, using an integrated analysis of questionnaire data (N = 98) and in-depth interviews (n = 10). Quantitative findings revealed that teachers strategically endorsed use of first language (L1) for specific purposes, with 77.6% supporting it to assist low-proficiency students and 56.1% recognizing its role in building rapport. A notable attitude-practice gap emerged, as reported classroom use of translanguaging (M = 23.53, SD = 6.65) exceeded attitudinal acceptance of it (M = 18.46, SD = 3.78). Qualitative analysis further illuminated four key dimensions: L1's cognitive utility for explaining complex grammar; its affective benefits in reducing anxiety; challenges posed by institutional English-only constraints; and teachers’ professional anxiety regarding perceptions of linguistic deficiency. Correlation analyses revealed that while teachers' general attitudes were moderately associated with acceptance of student L1 use (r = .32, p < .05), stronger relationships existed between self-perceived language proficiency and practical challenges such as time management difficulties (r = .67, p < .05). The study advocates professional development and policy reform for support contextually grounded translanguaging practices. Overall, the findings show that translanguaging must be locally grounded, calling for pedagogical reforms that reflect teachers’ lived realities, institutional pressures, and broader ideological environments.
Adult silent speakers: A nihithaw perspective
(2025) Ross, Charlotte; McIvor, Onowa
My doctoral research focuses on adults who were raised hearing and understanding their Indigenous language but are not speakers, commonly considered ‘silent speakers’ (Basham and Fatham, 2008; Elijah, 2020; First Peoples Cultural Council, 2016; Indigenous Languages Institute, 2021). Silent speakers are an untapped resource in the quest for Indigenous language revitalization and are poised to contribute in many ways as they possess a partial to a complete understanding of their Indigenous language including intonation, pitch and pronunciation. In my research, I sought to learn about the experiences of spoken language loss and language recovery for adult nīhithaw (Cree) silent speakers while exploring useful pedagogical methods that support silent speakers to reawaken their spoken language. I employed a mixed methods approach including an online survey, focus groups and interviews. I included two focus groups, one for silent speakers not actively engaged in language learning and the other for silent speakers engaged in language learning to become active speakers. This allowed me to compare their perspectives on activating their spoken language. One of the key messages across both groups was to create safety in language learning spaces to reawaken speaking the language. The first group emphasized the trauma experienced through shaming when trying to speak. The second group highlighted the critical need for access to proficient speakers. All participants loved to hear the language being spoken as it brought them a sense of healing. While the focus was on adult nīhithaw silent speakers, the findings can be generalized to other Indigenous language groups where silent speakers exist. This dissertation contributes to increasing our understanding of how best to support silent speakers to re-engage with speaking their language.