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Prioritization and Evolution of Regression Tests: Data-Driven Solutions for Continuous Integration Contexts
No full textRegression testing is a software testing method used to ensure that existing functionalities work correctly when changes are applied to a software system. It involves executing all or a subset of test cases. In Continuous Integration (CI) contexts, where code changes are frequent, regression testing is a critical process in ensuring software quality. However, the high time and resource costs of executing regression tests, coupled with the challenges of evolving test cases to align with rapidly changing software, pose significant challenges. This thesis addresses these challenges by optimizing the prioritization of regression tests and supporting their evolution following code changes.
The first part of the thesis focuses on Test Case Prioritization (TCP) to enhance the efficiency of regression testing in CI contexts. Many recent TCP studies employ Machine Learning (ML) techniques to address the dynamic and complex nature of CI. However, most of them use a limited number of features for training ML models and evaluate the models on subjects for which the application of TCP offers little practical value, due to their small regression testing time and low number of failed builds. This thesis begins by defining a data model that represents the data sources and their relationships within a CI environment. We used this model as the basis for identifying and collecting a comprehensive set of features, encompassing all features previously used in related studies. We collect these features from 25 open-source projects with significantly larger regression testing times and higher numbers of failed builds than existing benchmarks. Extensive experiments are conducted to assess the performance of ML-based TCP, evaluating its effectiveness, feature collection costs, and the decay rate of model performance over time. Additionally, this study examines the trade-offs between feature collection costs and TCP effectiveness, providing practical insights for deploying ML-based TCP in real-world CI environments.
The second part of the thesis introduces TaRGET (Test Repair GEneraTor), a novel approach for automating the repair of broken test cases. Ensuring the quality of software systems through regression testing is essential, yet maintaining test cases poses significant challenges and costs. The need for frequent updates to align with the evolving system under test (SUT) often entails high complexity and cost for maintaining these test cases. Broken test cases, if left unrepaired, degrade the quality of test suites, disrupt the development process, and waste developers' time. TaRGET leverages pre-trained code language models (CLMs) and treats test repair as a language translation task. It employs a two-step process that integrates essential contextual information, such as SUT code changes, and fine-tunes CLMs to enhance the accuracy and relevance of the generated repairs. To validate TaRGET, the thesis introduces TaRBench, a comprehensive benchmark containing over 45,000 test repair instances across 59 open-source projects, addressing the limitations of existing benchmarks, which often have a small number of instances or projects and lack diversity in test repair scenarios. Experimental results demonstrate that TaRGET achieves a 66.1% exact match accuracy in repairing test cases. The study further examines TaRGET's effectiveness across different test repair scenarios using both quantitative and qualitative analysis. Practical guidelines are also provided for identifying scenarios where the generated repairs might be less reliable. The study also examines the effectiveness of repair generation for new projects without fine-tuning and evaluates the necessity of project-specific fine-tuning for achieving acceptable performance.
By combining advanced ML techniques with practical tools and benchmarks, this thesis provides a unified framework for supporting the prioritization and evolution of regression tests. To enable reproducibility and reusability, all experimental data, tools, and benchmarks are made publicly available for practitioners and researchers
Association between a publicly funded universal drug program and antipsychotic and antidepressant medication dispensing to children
No full textAbstract Background The prescribing of antidepressants and antipsychotics to children has increased worldwide, but little is known about how changes in drug funding policy influence the practice. In 2018, Ontario introduced a universal pharmacare program (OHIP+) for children and youth, amending it in April 2019 to cover only those without private insurance. We examined the association of these policy changes with antipsychotic and antidepressant medication prescribing. Methods We conducted a population-based study of antidepressant and antipsychotic medication dispensing to children ≤ 18 years old between September 1, 2014, and February 29, 2020. We obtained dispensing data from the IQVIA Geographic Prescription Monitor database, and used interventional autoregressive integrated moving average models to examine whether the implementation of OHIP + and its subsequent revision were associated with changes in dispensing. Results The implementation of OHIP + was not associated with changes in the rate of antidepressants (-19.3 units per 1,000 population; 95% confidence interval [CI]: -41.7 to 3.1) or antipsychotics (+ 1.0 unit per 1,000 population; 95% CI: -5.4 to 7.5) dispensed. Similarly, subsequent changes to the program restricting coverage to children without private insurance were not associated with antidepressant (0.3 units per 1,000; 95% CI: -7.4 to 7.9) or antipsychotic (1.0 units per 1,000; 95% CI: -0.9 to 2.9) dispensing trends. Conclusion Implementation of a publicly-funded pharmacare program did not influence trends in antidepressant or antipsychotic medication dispensing among children
Correction: Content of a wound care mobile application for newly graduated nurses: an e-Delphi study
No full textExamining Constraints, Facilitators, and Negotiation in Skiing Participation: A Cross-cultural Study
No full textSports and leisure activities constitute a vital aspect of daily life. Although extensive research has developed various models and factors to understand sports participation, encompassing individual, sociological, and psychological perspectives (Grima et al., 2017), the focus has predominantly been on summer sports, resulting in a relative paucity of research on winter sports. A literature review on winter sports participation reveals a notable scarcity of theoretically grounded cross-cultural research (Hudson et al., 2010). Therefore, this dissertation underscores the influence of cultures on sports participation, focusing on the activity of downhill skiing while highlighting cultural differences that provide a foundation for further exploration of cross-cultural behaviour in the winter sports industry. To achieve this purpose, the focus was placed on two markets, specifically the Beijing (China) emerging market and Vancouver (Canada), a traditional and declining market. The research drew on leisure constraints, facilitators, and negotiation theory. This dissertation progressed through three distinct phases of research, each culminating in a research article. The first phase explored the relationship between constraints, facilitators, and skiing participation behaviour among participants in Beijing. The second phase involved a confirmatory analysis of the leisure constraints theory among participants in Vancouver, focusing on the relationships between constraints, facilitators, and skiing participation. In the final phase, negotiation strategies were examined in both cultural groups, generating valuable insights and implications for further empirical testing. Cumulatively, this dissertation makes conceptual and empirical contributions to the literature on downhill skiing by conducting a cross-cultural comparative analysis between an emerging and declining market. It offers valuable insights and actionable strategies for ski resort managers and marketers to attract more guests from China’s emerging ski market while addressing the decline and retaining current skiers in Canada’s declining ski market
Fluoroscopy-guided aspiration of the acutely dislocated total hip arthroplasty: a feasible, high-yield, and safe procedure
No full textAbstract Objective To determine the feasibility, yield, and safety of fluoroscopic-guided aspiration of the acutely dislocated total hip arthroplasty (AD-THA). Materials and methods IRB-approved, retrospective review of fluoroscopic-guided aspirations of AD-THA (January 2005–December 2023) was performed. Data from electronic charts and fluoroscopy images/reports were obtained. Positive yield was defined as spontaneous aspirate or saline rinse adequate for microbiology analysis. Sub-analysis by needle target (acetabular cup or femur) was performed for spontaneous aspiration rate, aspirate volume and fluoroscopy time. Differences between groups were analyzed with unpaired, t-test (2-tail) and between proportions with Fisher’s exact test, with significance p < 0.05. Results Aspiration of 20 AD-THA in 19 patients (12 female, mean age (SD) of 73 years (16)) targeted the acetabular cup in 45% (9/20) or femur in 55% (11/20) of cases. Positive yield was obtained in 95% (19/20), with spontaneous aspirate in 75% (15/20) and saline rinse in 20% (4/20) of cases; in 5% (1/20), no diagnostic sample was obtained. Spontaneous aspirate mean volume (SD, range) for all cases was 8.3 mL (6.9, 0.2–25), and higher when targeting the acetabular cup 11.2 mL (6.9, 5–25) versus the femur 4.0 mL (4.4, 0.2–12) (p = 0.026). The rate of spontaneous aspiration was higher for the acetabular cup 100% (9/9) versus the femur 55% (6/11) (p = 0.038). The mean fluoroscopy time (SD, range) for all cases was 43 s (25, 19–102), and shorter for targeting the acetabular cup 32 s (16, 19–75) versus the femur 56 s (28, 28–102) (p = 0.034). No immediate complications occurred in all aspirations. Conclusion Fluoroscopy-guided aspiration of AD-THA is a feasible, high-yield, and safe procedure. Targeting the acetabular cup results in a higher rate of spontaneous aspirate, larger aspiration volume, and lower fluoroscopy time. Critical relevance statement Although technically more challenging, radiologists should feel confident aspirating the acutely dislocated total hip arthroplasty (AD-THA) under fluoroscopic guidance. Key Points Total hip arthroplasty (THA) infection can be evaluated with synovial fluid aspiration. Fluoroscopic-guided aspiration of the dislocated THA is feasible, high-yield, and safe. Targeting of the acetabular cup is recommended over the femoral prosthetic component. Acetabular cup targeting gives larger, spontaneous aspirates with lower fluoroscopy time. Graphical Abstrac
Contributions to Statistical Theory of Data Privacy
No full textThis thesis explores key challenges and methodologies in the statistical theory of data privacy, focusing on disclosure risk assessment and synthetic data generation. The research reviews established privacy frameworks, such as k-anonymity,-diversity, t-closeness, and differential privacy, and highlights their practical limitations. To address these gaps, a new approach to Correct Attribution Probability (CAP) is proposed, utilizing equivalence classes to enhance applicability and interpretability. The thesis also provides a detailed analysis of synthetic data generation methods, assessing their utility and privacy implications, and thoroughly examines the Synthpop package. Several improvements to Synthpop are proposed, including better handling of data dependencies, the incorporation of privacy metrics like differential privacy, and more robust utility evaluation methods. These contributions aim to improve the balance between data privacy and utility
Unbroken: Stories of Strength, Solidarity, and Resistance from Canadian Federal Prisons Designated for Women
No full textHistorically, criminology has taken a deficit-focused or risk and needs-based approach to examining criminological issues (Kewley, 2017). Additionally, criminology has done little to explore how engaging in positive experiences can support criminalized people and prevent further conflict with the law (Ronel & Eisha, 2011). “Correctional” programming and policies employ a psychological lens, portraying women as having disordered thinking, irrational behaviours, personality disorders, along with many risk factors and needs that require “fixing” (Pollack, 2004). In response, there has been a proliferation of critical literature documenting incarcerated women’s harmful coping strategies in reaction to structural oppression and interpersonal harms, such as self-harm, suicide, eating disorders, and substance abuse (e.g., Chamberlen, 2018; Kilty, 2011, 2012, 2014; Moore & Scraton, 2014; Zinger, 2019). Less is known about incarcerated women’s strengths, skills, solidarity, resistance, and resilience. This project provides a more wholistic understanding of incarcerated women and gender-diverse people’s identities by challenging the prevalence of deficit-focused narratives and demonstrating the characteristics of resilient prisoners. A strength-based conceptual framework of prisoner resilience, linked to central features of healing and transformative justice, was developed to guide data collection and analysis. Mobilizing feminist, qualitative, and autoethnographic research methods within the critical paradigm, interviews were conducted with 13 key informants and 20 people who were incarcerated in federal prisons designated for women. Data were interpreted via thematic narrative analysis. This study’s findings reveal that promoting criminalized people’s strengths and fostering prisoner resilience can buffer the impact of the harmful conditions of confinement, support community re-entry, and contribute to transformative social change. The harms of the carceral state are severe and extensive, leading to further exclusion of some of the most marginalized people in society. Rather than interventions targeting the perceived deficits and needs of criminalized people, a strengths-based approach that promotes healing, resilience, and relational connections is needed to build safe, inclusive, caring communities
From social awareness to authoritarian other: The conservative weaponization of woke in Canadian parliamentary discourse
No full textThis study examines the evolution of (anti)woke discourse in debates within the Canadian House of Commons from 2019 to 2023, analyzing how “conceptual flipsiding” and moral panic operate to transform democratic language into tools of illiberal politics. Our critical discourse analysis of Hansard transcripts identifies three key themes: the semantic shift of woke from social awareness to authoritarianism, the strategic redefinition of woke by Conservative MPs — led by party leader Pierre Poilievre — to construct a moral panic around an anti-Canadian ideological Other, and inadequate attempts by MPs from other parties to challenge this negative framing. We argue that the discursive weaponization of woke demonstrates how political actors appropriate and invert democratic language to advance illiberal agendas while maintaining democratic legitimacy. This Canadian case illuminates broader patterns in how democratic language is manipulated across national contexts while revealing how ineffective counter-frames can inadvertently legitimize anti-democratic action within democratic institutions
Temperate Deciduous Trees in a Changing World: Their Phenology and Interactions
No full textThis thesis examines the ecological interactions within temperate deciduous forests, focusing on wild bees, trees, and understorey herbs, and how these species respond to climate change. In my first data chapter, using pan traps, I sampled bees in both the canopy and understorey of a temperate deciduous forest biweekly from early spring to mid-summer of 2021. My findings reveal that forest canopies are crucial yet often overlooked habitats for wild bees. A significant number of ground-nesting bees were found foraging in the canopy, with arboreal pollen, particularly from Quercus and Acer species, forming a substantial part of their diet. This suggests that excluding the canopy from bee community studies could lead to underestimating bee populations and overlooking key aspects of their foraging behaviour.
In my second data chapter, I analyzed 13 years of phenological data for 10 tree species and 11 springflowering forest herbs across 965 sites in northeastern North America, collected by citizen scientists under the USA-National Phenology Network. Contrary to expectations, the data showed that spring-flowering herbs advance their phenology more rapidly than trees in response to warming, particularly at middle and higher latitudes. This faster response may allow these herbs to extend their growing season and increase carbon uptake as temperatures rise. However, the variation in responses across latitudes and species highlights the complexities involved in predicting long-term ecological impacts.
Additionally, in my final data chapter, I investigated the temperature sensitivity of phenology in temperate tree species across Europe using leaf-out data from the Pan-European Phenology Project (PEP725) and climate data from the European Climate Assessment & Dataset (E-OBS). My analysis focused on the relationship between chilling accumulation and heating accumulations (CA-HR response rate) and how this relationship varies with local environmental conditions. The results indicate that populations in warmer, drier, and lower-elevation areas have weaker phenological responses to warming, while those in colder, wetter, and higher-elevation areas have stronger phenological responses to warming. This variation suggests that local adaptation significantly influences how different populations respond to climate change
RCMP Officers Posted to Nunavut Communities: Exploring the Policing and Private Life Challenges of Qallunaat Police in Inuit Nunangat
No full textAs a result of a signed agreement between the Government of Canada and Nunavut, the Royal Canadian Mounted Police (RCMP) is contracted to police Nunavut hamlets. This iteration of contracts began when the Territory was formed in 1999 and involves the recruitment of Regular Members from across Canada. To better understand the experiences of these Members, this thesis project engages with the literature on rural and remote policing, and explores the uniqueness of policing in Nunavut (Ruddell & Jones, 2018). Inspired by informal Member comments about the “harsh reality” of these posts, this project investigates accounts of everyday policing in several hamlets.
Through a qualitative approach, specifically semi-structured interviews, and framed by Settler Colonialism theory and Bourdieu's theory on Habitus, this project applies “policing habitus” to understand the daily living and working conditions of police officers in Nunavut. The analysis shows that officers identify a number of obstacles in their “field” of work, including insufficient resources for the communities of Nunavut, a complex array of responsibilities and requests that fall outside of police duties and yet to them, the complexities of negotiating relationships in small hamlets, and the frustration of feeling as though they are a “band-aid” solution to deep and historical issues. The thesis concludes with a series of policy recommendations