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Structural Assessment of Glued-Laminated Timber Columns Subjected to Real Fires
No full textThis thesis investigates the performance and post-fire structural integrity of glued-laminated (glulam) columns when exposed to real fires. The primary objective of the Mass Timber Demonstration Fire Test Program (MTDFTP) in Ottawa was to conduct large-scale fire tests to explore construction fire safety, fire behavior in open office spaces and residential areas, and the impact of exposed mass timber elements on fire intensity and duration. Detailed visual inspections and axial compression testing of the MTDFTP columns indicated differences between actual charring rates and rates predicted by CSA O86 (2019), and Eurocode 5 (2004). Uneven charring and adhesive degradation were significant factors affecting post-fire performance. Despite extensive charring, the columns retained much of their structural integrity, supporting potential repairs over replacement. This research gives an insight into the charring behaviour of glulam columns and recommends updates to fire safety standards, enhancing fire resistance and safety of timber structures
An Integrated GaN Power Amplifier at 5 GHz
No full textThis thesis presents the design and analysis of a fully integrated Gallium Nitride (GaN) power amplifier operating at 5 GHz, fabricated using the Skyworks 0.25 μm GaN process. The proposed amplifier is designed to be fully integrated onto a single die, with an OIP3 over 40 dBm, a maximum instantaneous bandwidth of 100 MHz, and a saturated power of 35 dBm into a 50-Ω load. The layout, extracted using EMX, confirms an OIP3 of 41.5 dBm, a single-tone gain of 9.5 dB, and a saturated power of 35 dBm. Although the final amplifier was not able to be taped-out, previously designed gain and power-matched amplifier test structures were measured and back-fitted to forecast the potential success of the proposed design
A Geometric Approach to Safe Control of Orbital Manipulators
No full textThis thesis focuses on the safe control of space manipulators using a rigorous geometric model and control approach based on Lie groups. We begin with a comprehensive literature review of in-orbit robotic servicing missions and common Guidance, Navigation, and Control (GNC) methodologies. We also survey geometric tools such as dynamic reduction and control on Lie groups for formulating the dynamics and kinematics of rigid multi-body systems relevant to space manipulators. We develop a combined form of Euler-Poincaré equations on Lie groups (for spacecraft) and Euler-Lagrange dynamical equations (for the equivalent fixed-base manipulator), called the Lagrange-Poincaré Equations (LPE), to establish a singularity-free formalism for spacecraft-manipulator dynamics. By introducing a block-diagonalized inertia matrix, we effectively separate external (locked-arm rigid system) and internal (arm's motion) dynamics. Symmetry-breaking external wrenches and control forces on each degree of freedom are also efficiently incorporated into the system. We extend the LPE to a singularity-free formulation of in-orbit disturbed dynamics relative to a non-inertial orbital frame, integrating Euler-Lagrange equations, Euler-Poincaré equations, and Kepler's equations for orbital dynamics. Leveraging the unique geometric characteristics of the model, we design a full-pose workspace controller that applies feedback linearization on the corresponding Lie group of the relative poses between the end-effector and the target. We propose an intrinsic feedforward-feedback PID control law on Lie groups for comprehensive full-pose regulation, incorporating measures to avoid kinematic and dynamic singularities and workspace boundaries. Additionally, we develop (i) a manipulability optimization algorithm, (ii) a collision-avoidance method, and (iii) a full formulation and proof of the internal/external stability and boundedness of null-space states of the system. Finally, we demonstrate the robustness and features of the controller through a comprehensive series of experiments in Simulink, showcasing its resilience to inertial uncertainties and measurement noise
Petrology, Age, and Alteration of Gabbroic Rocks of the Katangan Large Igneous Province, Central African Copperbelt, Zambia
No full textCopper and cobalt are essential elements required to support an electrified economy because of their critical role in lightweight electric batteries and transmission lines. Their main global source is the sedimentary rock-hosted deposits of the Central African Copperbelt (CACB), however, the reasons why it occurs in such abundance remain obscure. In addition to copper and cobalt, the CACB deposits also contain significant amounts of other necessary elements for a low-carbon transition such as zinc and nickel. The CACB contains Neoproterozoic Katangan intrusive rock series, comprising gabbro and metagabbro sills and basaltic dykes and flows. They are herein characterized as a large igneous province distributed throughout the 450 km long and 600 km wide arcuate CACB in southeastern Democratic Republic of Congo and northwestern Zambia. Understanding the petrogenesis of these mafic intrusive rocks is vital to assist future studies of their relation to the vast Cu and Co deposits in the CACB and to understand their links to Rodinia’s breakup. Lithogeochemical data suggest that these rocks were formed due to an extensional regime with potential plume involvement that developed during a rifting stage of the CACB. Petrological modeling demonstrates how these rocks were derived from primitive magmas and evolved chemically through fractional crystallization, assimilation, and magma mixing, generating a range of compositions with close chemical affinity. Though the Katangan magmatism does not have preserved the areal extent and volume of igneous rocks required to be classified as a large igneous province, it still may represent one that has been severely weathered and only portion of it is left. Other characteristics like chemical composition and geotectonic environment serve as evidence as they are comparable with other large igneous provinces worldwide such as the Paraná-Etendeka large igneous province. The mafic intrusive rocks of the Katangan large igneous province within the Mwashya Subgroup of the Domes region and southeastern Congolese Copperbelt returned two new high-precision U-Pb CA-ID-TIMS zircon ages of 740.3 ± 1.1 Ma and 741.1 ± 1.5 Ma. These results are statistically indistinguishable from but of much higher precision than the previously published U-Pb LA-ICP-MS and SHRIMP zircon ages for Katangan rocks
Knots of Radical Flows: Design Rooted in Cultural Anthropology, and Material Phenomena
No full textThis thesis investigates cultural artifacts, stories, and the process of making, as offerings of intuitive anthropological knowledge that can inform innovative research and design. Weaving is a shared human experience and a reflection of how our species interacts with the material and conscious world. Through such handcrafts, we have revealed and appropriated the potential of fibers when woven into patterned textiles and structured configurations. This potential has been leveraged to develop an experimental structural system that incorporates fibrous materials’ inherent properties. Steam-bent plywood strips have been configured into fibrous columns that splay apart to form a dynamic equilibrium, offering a context to inspire creation and discourse. The thesis reflects on the Tagalog prefix ‘Ka’, which means complementary connection, and a pavilion with multi-cultural resonant potential. The pavilion is a contemporary reimagining of the Filipino ‘Primitive Hut’ and facilitates an exhibition that highlights the connectedness that all humans share
Development of Energy Disaggregation Algorithms for Commercial Buildings
No full textEnergy management in commercial buildings requires accurate measurement of end-uses, which is crucial for sustainability and cost reduction. However, a common challenge is the lack of high-resolution energy submetering, hindering effective energy management. To this end, a suite of load disaggregation algorithms suitable for buildings with and without building automation systems (BASs) is developed in this study. The thesis consists of four parts. The first part uses multiple linear regression models estimated by the genetic algorithm and a least-square solver to disaggregate heating and electricity data using BAS data as predictors. The method was tested on data from an Ottawa office building and showed accurate disaggregation into end-use categories, such as occupant-controlled loads and distribution loads for electricity, air handling unit (AHU) heating coils, and perimeter heating devices for heating. The second part explores the impact of submeter density and configuration on the disaggregation strategy using BAS trend data as predictors. Findings highlighted factors affecting the minimum number of submeters needed for accurate disaggregation, providing insights for building design codes, energy consultants, and policymakers. The third part proposed a time-series decomposition-based method to disaggregate major energy end-uses without BAS trend data. Data from ten office buildings in Ottawa were used to break down total energy use into three major end-uses. Disaggregation results were compared with actual submeter data, and insights into lighting and thermal scheduling were assessed. The proposed method showed promising performance, suggesting potential for quick and low-cost auditing of commercial buildings with limited submeter data access. The fourth part of this thesis utilized the developed disaggregation algorithms integrated into a visualization tool for end-users to interact with disaggregated data. Additionally, preliminary recommendations for thermal submetering requirements were incorporated based on the findings presented in the second part of the thesis. This thesis enhances energy management in commercial buildings by developing practical energy disaggregation techniques using BAS trend data, investigating submeter density and configuration, proposing a time-series decomposition-based method, and integrating techniques into a visualization tool, providing guidance for facility managers and operators to optimize energy consumption and improve sustainability
The Fusion of Multilingual Semantic Search and Large Language Models: A New Paradigm for Enhanced Topic Exploration and Contextual Search
No full textDigital news articles are often considered as a primary source of information in today's information-driven society which requires query processing methods to handle the ever-increasing volume of content and various forms of queries. Our goal is to develop a novel approach that can improve the way users access and retrieve news by considering Natural Language Processing (NLP)-driven query processing for news articles. This will address the complexities of news articles written in multiple languages and covering a range of topics. The proposed method helps in enhancing the performance of query processing in applications such as journalism, academic research, and content suggestion. By conducting experiments with Sentence Embeddings, Large Language Model (LLM), and Approximate Nearest Neighbours (ANN), this thesis improves news article search systems. Results show that the method improves the quality of the search results for the queries to return more accurate and relevant search results across different languages
Ionkwa'nikonri:io: “Living a Good Life”: Embracing the Land to Promote Wellness
No full textIndigenous communities have experienced disconnection from their ancestral lands and territories because of colonization and settler invasion. The arrival of settlers disrupted traditional knowledge systems, contributing to a loss of connection to cultural teachings, practices, land, language, and cultural identity. This disruption has contributed to significant stress and mental health challenges within Indigenous communities. This dissertation research examines the impacts of persistent colonial and intergenerational trauma on the relationship between Indigenous Peoples and the land, particularly the Kanienkehaka. Applying Indigenous Wholistic Theory and Community-Based Participatory Research approaches this research aimed to gain insight into how communities understand the land and their connection to the land as a source of healing. The following questions were posed: 1) What does the land mean to you”? 2) What do “land-based teachings and practices” mean to you? 3) How does the terminology affect youth motivation to become involved with land-based teachings and practices or rephrased what are the potential barriers or challenges for youth connecting to the land? This study involved 30 unstructured interviews with representation across generations (young people, Generation X (30-35 years), and Elders) from the community of Akwesasne. Qualitative data analyses identified three themes: Impact of colonization, role of cultural teachings, and relationships with the land. Across generations, similar challenges to engaging with the land were identified, including social media, substance use, and parenting. These shared experiences highlight the challenges faced across generations. Cultural teachings, including Creation Stories and traditional ceremonies, were consistently reported as highly valued across generations. The land was deeply connected to identity and well-being, with all participants recognizing its significance despite varying levels of engagement. When the results of the present study were shared with Elders, that connected the pattern of findings to the Cycle of Ceremonies as a unifying process across generations. The research underscored the possibilities for collaboration across generations to overcome barriers and opportunities to enhance cultural practices and teachings. A call is made for integrating participatory practices and traditional knowledge into social work and policy to promote culturally appropriate healing approaches and to foster Indigenous and non-Indigenous collaborative spaces that support communities
Location-Based Sentiment Analysis using Bayesian Networks on COVID-19 Twitter Data
No full textThe onset of the COVID-19 pandemic and the various variants within it have caused mass public opinion, and many turn to web services and social media platforms to easily and quickly voice these opinions. Of these services and platforms, the microblogging platform Twitter has been widely used by people around the world to voice their opinions on the COVID-19 pandemic. Twitter poses unique challenges which stem from the 280 character limit imposed on a given tweet. Further, advances in technology allow for a precise location to be determined upon the submission of a tweet. This thesis deploys the tree augmented naïve Bayes (TAN) classifier sentiment analysis technique to analyze the sentiment towards and between the B.1.1.529 BA.1 Omicron and B.1.617.2 Delta variants of the COVID-19 pandemic across provinces and territories within Canada
Community Engagement, Collective Spaces, and Well-Being in Community Housing Neighborhoods: The Case of Foster Farm, Ottawa
No full textThe relationship between architecture and well-being is a complex and evolving topic, yet often underutilized. This study delves into the relationship between architectural design, collective spaces, and the well-being of individuals within social and community housing neighborhoods. This research project is grounded on my experience volunteering at the Ottawa community of Foster Farm between 2014 and 2018. Through my involvement in the Junior Youth Spiritual Empowerment Program and other community-building activities at Foster Farm, I learned about the absence of suitable collective spaces in the area which caused significant challenges in sustaining regular community activities. Employing a mixed-methods approach, including first-hand experience, consultations with residents and social workers, and urban theories on design and well-being, this study identifies ways in which the neighborhoods can be more supportive of their resident’s needs and aspirations. The research also offers insights into effective and ethical ways to engage communities through service and listening