21793 research outputs found
Sort by
Risk-based seismic safety assessment of concrete gravity dams with uncertainty quantification
Get PDFDams are vital national assets that play a crucial role in water storage, hydroelectric power generation, and flood control. Globally, over 61,000 large dams have surpassed 50 years of service, and many show signs of deterioration. With over 300 dam failures recorded worldwide, the potential for catastrophic damage remains alarmingly high if these aging structures are not properly maintained and upgraded. Further, many of the existing dams were built upon outdated standards, and there is an increase in seismic hazards making it imperative to reevaluate their seismic performance to align with current safety standards. The need for improved dam safety measures is urgent, as dam owners, regulators, and policymakers grapple with the challenges of ensuring the structural integrity of aging dams in the face of growing risks. A key solution is shifting from traditional safety approaches to a modern, risk-based methodology, which addresses safety concerns more efficiently and economically. Various, global agencies have developed risk-based safety assessment guidelines; however, these often lack systematic implementation frameworks and sufficient reference studies, making them difficult for dam owners to adopt effectively. Furthermore, various uncertainties can impact the risk assessment and can complicate efforts to ensure dam safety. In this context, this research investigates uncertainties impacting seismic risk assessments for dams, including modeling choices, ground motion selection, aging, and material variability. Case studies of the Koyna Dam and Pine Flat Dam were used to evaluate these factors at each stage of performance evaluation: system response, fragility, and risk assessment. Key findings indicate that dam-foundation-reservoir (DFR) models incorporating acoustic elements exhibit less variability in system response, regardless of model complexity and solution procedure. Ground motion derived from the conditional mean spectrum (CMS) method yields better fragility estimates than the ASCE 7-16 standard, particularly for moderate to severe damage states. Additionally, aging and material variability significantly affect the dynamic characteristics of dams, with increased failure probabilities correlating with both age and return period. Based on these findings, the research proposes a comprehensive, systematic framework for risk-based seismic safety evaluation. This framework aligns with safety assessment objectives and ensures optimal use of computational resources
Stress and family dysfunction: Examining their influence on mental health outcomes and service use in the offspring of parents with affective disorders
Get PDFOffspring of parents with affective disorders (OAD) are at risk of developing a wide range of mental disorders. Deficits in the rearing environment and exposure to adverse events are well known risk factors for negative outcomes in OAD. Building on prior research, this thesis aimed to examine the longitudinal relationships between familial dysfunction, exposure to adverse events, emotional and behavioural well-being, and mental health service utilization in OAD and control offspring of parents with no affective disorder. Studies 1 and 2 in the thesis used data from the TRacking Adolescents’ Individual Lives Survey, a longitudinal study of youth in the Netherlands. 2230 participants (51% female, Mage= 11.1 years, SD = 0.6, at baseline) and their parents completed questionnaires across 6 time points, spanning 15 years. Mental health and behavioural data were measured using standardized questionnaires, while adverse life events and health service utilization were assessed using structured interviews. In the first study, multi- group structured equation modelling revealed that family dysfunction was linked to internalizing and externalizing problems in the OAD (B = 0.05, SD = 0.02, p = .008), but not in controls (B = 0.06, SD = 0.01, p = .636), and that this relationship was stable from middle childhood to adulthood. In the second study, we expanded the scope of investigation from family functioning to cumulative environmental risk, referring to the assessment of multiple risk factors in families, and mental health service utilization. Results from moderated mediation analyses revealed that the OAD were more likely to seek out more intensive mental health services as adults than controls (CI = [0.01, 0.15]), as a function of their cumulative environmental risk and subsequent significant mental health need. Study 3 examined whether a preventative intervention to improve family functioning in OAD might improve offspring’s internalizing and externalizing symptoms through changes in parenting stress. In this study, we compared the offspring of a parent having bipolar disorder (OBD), who underwent the Reducing Unwanted Stress in the Home (RUSH) intervention program, with control offspring. Designed as a quasi-experiment, in which the control group underwent an assessment-only condition, families of both groups completed assessments pre- and post-intervention, as well as at 3- and 6-month follow-ups. Mixed-modelling analyses revealed that improvements in parenting stress mediated the relationship between participation in the RUSH program and reduced offspring internalizing and externalizing symptoms at a six-month follow-up. Taken together, the results show that the OAD may be especially sensitive to stress in the rearing environment as compared to offspring of parents with no affective disorders. Adversity and dysfunction in the home environment might be a particularly salient risk factor for OAD, leading to the development of emotional and behavioural problems, as well as costly mental health interventions. Interventions aimed at improving the rearing environment during childhood may therefore improve developmental outcomes in the OAD and decrease the cost-of-care for these high risk families, as evidenced by the findings of this thesis
Seismic analysis of concrete gravity dams using a novel time domain spectral finite element method
Get PDFThis thesis introduces a two-dimensional spectral finite element formulation tailored for the dynamic analysis of concrete gravity dams. While the Finite Element Method (FEM) is widely utilized for dynamic structural analysis, its application to large structures often demands substantial computational resources and time. To address this challenge, alternative modelling techniques known as Spectral Finite Element Methods (SFEMs) have been developed over the past decades to enhance computational efficiency.
The objective of this thesis is to develop a computationally efficient analysis procedure for dynamic analysis of large structures like concrete gravity dams and then apply the developed procedure for assessing the behaviour of dams subjected to seismic ground motions as well as deterioration effects like alkali-aggregate reactions.
The Time Domain-based SFEM (TDSFEM) was chosen for dynamic time history analysis of concrete gravity dams due to its advantages over the Frequency Domain-based SFEM (FDSFEM). TDSFEM is particularly effective in handling irregular geometries and finite domains, making it a better choice for complex structural analyses. Sensitivity analyses and convergence studies were conducted using both 4-noded and 9-noded elements, revealing TDSFEM’s superior computational efficiency, especially when higher-order elements are employed.
Comparative studies between TDSFEM and conventional FEM highlighted TDSFEM's advantage in reducing computational time while maintaining accuracy in large-scale dynamic analyses. Modal analysis and time history analysis indicated that TDSFEM, when used with higher-order elements, could be a practical alternative to conventional FEM, offering substantial time savings without sacrificing precision.
The study also investigated damage detection methods based on modal parameters, including displacement, curvature, and strain energy. Among these, modal strain energy emerged as the most effective and reliable indicator for identifying and localizing damage. Additionally, TDSFEM was applied to model the behaviour and failure modes of FRP-reinforced concrete deep beams, with results closely matching experimental data, further demonstrating its efficiency.
Moreover, the thesis introduced a simplified thermo-mechanical approach for modelling deterioration effects, such as alkali-aggregate reactions (AAR), providing a novel alternative to existing chemical reaction-based models. TDSFEM is thus presented as a viable, efficient method for analysing large structures, offering significant time savings and effective applications in damage detection and deterioration modelling
Reimagining Canadian Journalism: A Case Study of News Startups in Montreal
Get PDFThe Canadian journalism industry has been in a self-described crisis, partly of its own making, for arguably as long as it has existed. With each new technological advancement comes a new wave of self-doubt, and in the past five years, many legacy news outlets have turned to the federal government for financial help. At the same time, a new crop of digital news startups has grown. Their numbers fluctuate, but at least 270 digital-first outlets existed in Canada as of last year (LION Publishers, 2023). These outlets tend to be more independent and less nostalgic about journalistic norms and traditions, forging new approaches to information-gathering and sharing. As trust in news media has generally eroded (Reuters, 2024), many news startups have responded by focusing on hyperlocal or niche information needs, and on direct audience engagement. Some are also exploring philanthropic funding opportunities or seeking out non-profit status, effectively turning the capitalist, ad-revenue-driven newspaper model on its head. Through a series of three 30- to 50-minute podcasts, three Montreal-based case studies – La Converse, The Rover and Pivot – are examined to help answer the question: As Canadian legacy news media crumble, how will the new kids on the block respond? Judging by interviews with the founders of the three news outlets, the next generation of journalism leaders value slowing down to conduct more long-form and investigative reporting; spotlighting voices that have been traditionally marginalized in the media; and, for some, favouring radical transparency over neutral objectivity
Acting Now or Later: The Role of Message Framing and Temporal Distance in Promoting Sustainable Consumer Behavior
Get PDFPromoting sustainable behaviors is essential in addressing the severe environmental challenges posed by human activities. Prior research on persuasive messaging has extensively explored the efficacy of gain vs. loss message framing. When it comes to environmental sustainability, gains (i.e., benefits) and losses (i.e., harms) often accrue in the future, thus temporal distance is an important dimension. The efficacy of presenting gains and losses in the present vs. future remains underexamined in the context of sustainability messaging. In particular, I discuss two theoretical perspectives that make different predictions about how message framing may interact with temporal distance to shape behavior. Across three studies, this thesis investigates how these variables influence purchase intentions for sustainable products. Study 1 found a significant interaction between framing and temporal distance—future-oriented loss messages led to higher purchase intentions than present-oriented loss messages, while temporal distance did not impact gain-framed messages. Study 2 replicated the effect for loss-framed messages, while gain-framed messages exhibited the reverse effect—purchase intentions were higher when gains were present- rather than future-oriented. These effects were marginally significant. Study 3 attempted to replicate these results, but found null effects. Overall, this thesis highlights the complex interplay between message framing and temporal distance, suggesting that the current understanding—both theoretical and empirical—of this topic remains incomplete. Lastly, theoretical contributions, practical implications, and future directions for research are discussed
Automated Fault Detection and Diagnosis in Light Commercial Building’s HVAC systems
Get PDFFault detection and diagnosis (FDD) in commercial buildings' HVAC systems can significantly reduce energy consumption. Faults in these systems occur due to various issues such as aging and inadequate maintenance. Commercial buildings in Canada covered an area of 709,029,612 m² in 2019, consuming 948,216,746 GJ of energy. HVAC systems are responsible for 25%-50% of this energy consumption. In the United States, faults in HVAC systems contribute to an additional energy consumption of 103 to 500 terawatt-hours (TWh) in the building sector. Detecting and diagnosing faults in HVAC systems can reduce energy consumption by 20% to 30%. Light commercial buildings, defined as commercial buildings with fewer than six stories and less than 2500 square feet, include bank branches, offices, and small industrial facilities. These buildings have similarities in the configuration and size of HVAC components, making it feasible to develop an FDD tailored for this class of buildings, that can be easily scaled up. This goal can be achieved using data-driven methods, which have gained popularity over the past decades by installing various sensors and collecting data integrated with Building Energy Management (BEM) systems. In this thesis, three different FDD methods have been developed and validated on light commercial buildings. The first method is a semi-supervised method that includes various techniques to handle the unlabeled raw data from BEMs, resulting in a final supervised Automatic Fault Detection (AFDD) system. The second method is a fully unsupervised novel AFDD method based on PCA time series fault detection. The third method is primarily based on the inverse model of the Air Handling Unit (AHU) of the HVAC systems. A typical light commercial building in Montreal, Canada, was used for all methods. Additionally, to validate the generalizability of the unsupervised method, another light commercial building, a small industrial facility in Ireland, was used as well. The first method successfully resulted in an AFDD that can detect and diagnose faults with almost 90% accuracy, performing better in condition-based faults than control faults. The unsupervised method showed very good results in terms of generalizability. It was able to detect faults and report the problematic inputs and locations to the HVAC operators. Although the unsupervised method cannot completely diagnose condition-based faults, it provides very good information based on the system's behavior, enabling operators to diagnose the faults. Finally, the inverse modeling revealed that a physics-based neural network can outperform neural networks and genetic algorithms in modeling the system inversely and detecting anomalies mostly related to energy consumption
The Cinemafication of Video Games: An Examination of the Effect of Medium on Genre Through the Comparison of Films and Video Games
Get PDFFilms and video games may initially seem to have more elements in common than not, but upon closer inspection, it becomes apparent that the two audio/visual mediums are equally as different as they are similar. An effective method to facilitate a lucrative comparative analysis is to examine the two mediums through the lens of shared genres. Game scholars, such as King, Krzywinska, and Wolf, have long argued how to best analyze the topic of genre within the medium of games, and by combining concepts from these texts with the work of film theorists, including Neale and Schatz, this thesis aims to introduce a novel system of generic classification that allows for a better comparison between similar films and games and a closer examination of how games utilize genre. Through the direct comparison of films and games, it becomes apparent that as the video game industry has evolved, games have gradually become more recognizably cinematic, a phenomenon that this thesis dubs as cinemafication, which can best be identified as the consistent trend of video game graphics and narratives increasing in complexity, allowing for more cinematic potential, thereby closing the gap between the mediums of film and games. By closely examining generic case studies of the action and gangster genres, this thesis will apply a novel system of generic categorization in order to explore the intricacies of how genres are affected by the medium through which they are presented
The Eye, the Heart, and the Network: the Humanistic Blogging of Tumblr’s Webweaving Community
Get PDFWebweaving is a networked, creative archival practice hosted on the social blogging platform Tumblr. Weavers combine text, images, and other media elements and compile them into posts reflecting personal or intimate themes which fellow users can then share and recreate. The creative process of weaving reflects the values and ethics of Web 1.0 (connectivity, expression, dehiearchized content) and as such does not follow conventional trajectories of platform presence and art consumption of the contemporary digital landscape. Employing network ethnography and research-creation, this thesis answers three major questions. First: what is webweaving? Second: what does webweaving reveal about cultural production and digital life on Tumblr? Third: how do Tumblr users use webweaving to create humanistic meaning and connection online in an increasingly corporate platform landscape?
'
Operating at the intersection of platform studies and digital art history, this thesis documents an understudied and uniquely ‘born digital’ creative phenomenon. Drawing from theoretical frameworks like Jennifer Pybus’ work on platforms as archives of feelings, we build on existing platform theory to study the symbiotic relationship between art and community. Finally, we fill a research gap in the paradoxical nature of the Tumblr user experience in 2024, as weavers participate in thriving and irreplicable digital life on a platform that is considered long past its prime
Picturing Anonymity: An Empowering Method of Representing Gender-Based Violence
Get PDFABSTRACT
Picturing Anonymity: An Empowering Method of Representing Gender-Based Violence
Marta Malvina Mostardini
Gender-based violence (GBV) is a pervasive global issue affecting one in three women worldwide (World Health Organization, 2021). Despite photojournalism’s potential to expose injustices and shift public perceptions, mainstream media often reinforces stereotypes that contribute to the normalization or sensationalization of GBV. In Italy, media portrayals of survivors of GBV frequently result in secondary victimization, reinforcing their stigmatization as mere victims rather than recognizing their agency and resilience. This Research-Creation Thesis introduces an innovative approach to representing GBV, empathizing survivor collaboration and anonymity. The core of this work is a set of guidelines, titled “Empowering Anonymity: A Visual Method of Representing Gender-Based Violence” designed for photojournalists, journalists, and those seeking to challenge the stereotypical portrayal of GBV. These guidelines outline ethical practices for engaging with survivors and anti-violence organizations in Italy, focusing on visual techniques to protect their identities. The guidelines are exemplified by a prototype photo essay, “Fragments of Self”, which demonstrates how picturing anonymity can convey fragments of a person’s identity without fully revealing who they are. This prototype is conceptualized through trauma-informed journalism practices and Pierosara’s theory of ‘fragments of violence,’ which suggests that presenting partial glimpses of a survivor’s experience can convey the essence of their story while respecting their privacy and dignity (Pierosara, 2019). By implementing these guidelines and exploring the prototype photo essay, the thesis aims to contribute to ethical practices in photojournalism, inspire survivors of GBV to share their stories, and challenge stereotypes. Ultimately, it seeks to contribute to the empowerment journey of survivors
“This Game Made Me Cry”: A Material Auto-Ethnography of Pilgrimage and Video Game Design
No full textInitiated during COVID, this research utilizes material autoethnographic methods to study the video games Gris, Journey, and Season: Letter to the Future. This thesis contributes to 1) the debates in pilgrimage and cyberpilgrimage around the validity of a pilgrimage not physically taken, 2) the potential of a relationship between games and pilgrimage and what that reveals about both mediums, and 3) offering tools to game designers looking to replicate the emotional experiences felt in each of the games played, asking: what do video games as a medium afford pilgrimage, what does pilgrimage offer journeying games, and what can we learn about digital journeying through their comparison? Is playing a video game the same as doing a terrestrial pilgrimage?
This work concludes that playing a video game is not the same as doing a terrestrial pilgrimage, but that it has specific affordances and constraints which make it affective due to the way it attends to the body, senses, material, locality, and everyday. It is a counter-argument to the idea that both play and cyberpilgrimage are disembodied. Games afford a unique kind of experience and transformation for undertaking pilgrimage, and pilgrimages afford a unique kind of play. As such, to ask at what pilgrimage and games can afford each other is not to assert dominance (or homogeneity) between terrestrial and cyber- pilgrimage, but rather to ask at large: What are the varieties of meaning derived from different forms of pilgrimage and what brings them about