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  • Multi-Agent Deep Reinforcement Learning Assisted Pre-connect Handover Management

    Resource Type:
    Thesis
    Creator:
    Wei, Yao
    Abstract:
    This thesis proposes a MBB adopted handover mechanism, namely, pre-connect handover (PHO). PHO aims to provide a seamless and reliable handover for 5G networks. PHO utilizes DQN algorithm to facilitate the sequential decision-making problem of target base station (BS) selection based on the RSRQs and RSRQ change rates of all the surrounding candidate BSs. A MADRL solution is tailored to extend the DQN-assisted UE-associated PHO management for modeling a multi-UE scenario, where the autonomous agents learn the action policy by interacting with the environment in a distributed manner. The feasibility of PHO has been validated extensively via NS-3 and NS3-Gym. The experimental results demonstrated that the proposed PHO is not only achievable, but also that the DQN-assisted PHO technique can productively accomplish the optimal BS selection to maximize the PHO success rate. Moreover, the MADRL-assisted solution can also be conducted and effectively applied to a realistic multi-UE environment.
    Thesis Degree:
    Master of Applied Science (M.App.Sc.)
    Thesis Degree Discipline:
    Engineering, Electrical and Computer
    Date Created:
    2022

  • The Mantle Source of the 2.7 Ga Fe-rich Qullinaaraaluk Intrusion (NE Superior Craton) inferred through long- and short-lived Sm-Nd Systematics

    Resource Type:
    Thesis
    Creator:
    Mount, Sarah Marie
    Abstract:
    To provide insight into the Fe-enriched mantle domains that may be the source of ferropicrites, we present a coupled 147Sm-143Nd and 146Sm-142Nd study of the Neoarchean Fe-enriched Qullinaaraaluk intrusion (NESP). An isochron yields an age of 2706 ± 29 Ma, which is interpreted to be the crystallization age of the intrusion. Accounting for the effects of crustal contamination, the initial Ɛ 143Nd values range from -0.39 to +1.26. High-precision measurements of 142Nd/144Nd ratios yield an average μ142Nd of -0.4 ± 5.5, revealing no deviation from the terrestrial standard. The absence of μ142Nd anomaly indicates that the Qullinaaraaluk mantle source does not have a Hadean-formed component. Time-integrated 147Sm/144Nd ratios between 0.1944-0.2012 suggest derivation from a mantle source more enriched than the present-day depleted mantle. Similarities between the initial Ɛ 143Nd of the Qullinaaraaluk intrusion and Superior province ferropicrites indicates that their Fe-enriched mantle source may share a similar history.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Earth Sciences
    Date Created:
    2022

  • Characterization and Classification of Fibrillar Collagen Networks using Gray-Level Texture Analysis

    Resource Type:
    Thesis
    Creator:
    Poole, Joshua James Andrew
    Abstract:
    Biological tissues are a combination of cellular and acellular components. The extracellular matrix (ECM), or the acellular component of tissues, is often overlooked. Tracking changes in the ECM grants insight into how aging, diseases and treatments might affect tissue structures and cellular responses. Using gray-level texture analysis, we analyzed the architecture of fibrillar collagen, a major component of the ECM. Several gray-level textural features were extracted from second harmonic generation (SHG) images and used to characterize collagen network arrangements. This work provides a basis for a classification model aimed to track changes in the cellular microenvironment. This information is vital if we wish to continue exploration of how diseases develop in different tissues, and develop novel and effective treatments for different types of chronic diseases.
    Thesis Degree:
    Master of Applied Science (M.App.Sc.)
    Thesis Degree Discipline:
    FLAG
    Date Created:
    2022

  • Juvenile Stress: A Sensitive Period of Vulnerability on Hippocampal CA2 and Social Recognition Memory

    Resource Type:
    Thesis
    Creator:
    Maletta, Teresa
    Abstract:
    Social memory is the ability to discriminate between two or more conspecifics. The hippocampal CA2 is essential for social memory; dysfunction leads to social memory impairments. Early life stress has been found to cause social memory impairments. We examined whether social memory impairments observed after juvenile stress were due to CA2 dysfunction. Long-Evans rats were exposed to juvenile stress during P19-21. Social memory was recorded in early adulthood (P60/P61). Tissue was collected to determine CA2 cFos expression using nickel-enhanced 3,3'-Diaminobenzidine (DAB) immunohistochemistry. Adults exposed to stress did not differ from controls in sociability. However, they displayed social memory deficits, with a greater deficit in females. We also determined that juvenile stress significantly decreased cFos-positive cell density within the CA2, exhibiting reduced neuronal activity. These findings indicate that the CA2 is vulnerable to stress during the juvenile period, with long-term effects that persist throughout adulthood.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2022

  • Mining Collapse: Life and labour on the Cerro Rico de Potosí

    Resource Type:
    Thesis
    Creator:
    Francescone, Kirsten
    Abstract:
    This dissertation analyzes the relationship between small-scale miners (called cooperatives) and a transnational mining company (Manquiri) as they work alongside one another in the nearly 500-year-old mines in Potosí, Bolivia. I argue that traditional small-scale miners are undergoing a process of dispossession as the metabolic relationships required by the capitalocene continue to accelerate on the mountain. As miners struggle to maintain autonomy from capital over their workspaces and lifeworlds, the historic mountain, their means of subsistence and so much more, is crumbling around them. I interrogate claims against the sector as the one responsible for the mountain´s demise, and demonstrate that, in the context of ecological collapse, small-scale cooperative miners resistance to being subsumed by predatory capitalist relations of production, sheds light on the kinds of post-capitalist ecological labour we need.
    Thesis Degree:
    Doctor of Philosophy (Ph.D.)
    Thesis Degree Discipline:
    Anthropology
    Date Created:
    2022

  • Measurements for the Production Cross-section of a Z Boson in Association with High-transverse-momentum Jets with the ATLAS Detector at the Large Hadron Collider

    Resource Type:
    Thesis
    Creator:
    Laurier, Alexandre
    Abstract:
    In this thesis, the measurements of the production cross section of a Z boson produced in association with high-transverse-momentum jets and decaying into a charged- lepton pair are presented. The data used for these measurements are analyzed from proton-proton collisions at the Large Hadron Collider. The dataset corresponds to an integrated luminosity of 139 fb−1 collected at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector between 2015 and 2018. The cross-section measurements are performed separately for the electron and muon decay channels of the Z boson and then combined in order to increase the precision of the final Z(→ l+l−)+jets measurements. Events with at least one jet with pT ≥ 500 GeV/c are selected and populate a high-pT region. In this region, the production of an on-shell Z boson radiated by a quark is enhanced and results in events with a small angle between the Z boson and the associated quark jet such that the two objects are measured to be collinear. A fraction of the events in the high-pT region are also described by Z+1 jet events where the Z boson and the jet recoil against each-other such that the two objects are measured to be back-to-back. The large dataset has made it possible for the first time to separately study these two event topologies where a Z boson and a jet are either collinear or back-to-back. This is achieved by measuring the angular correlation between the Z boson and the closest jet. The production of a Z boson in association with jets, Z+jets, provides a near inexhaustible amount of information about the physics mechanism for the production of vector bosons at the Large Hadron Collider. This analysis allows to measure the cross section of Z+jets as a function of characteristic observables. The resulting differential cross sections are compared with state-of-the-art theoretical predictions. The differential cross sections themselves provide a powerful way to test the Standard Model and in particular quantum chromo-dynamics. The data are found to agree with the latest next-to-next-to-leading-order and next-to-leading-order theoretical predictions for Z+jets production.
    Thesis Degree:
    Doctor of Philosophy (Ph.D.)
    Thesis Degree Discipline:
    Physics
    Date Created:
    2022

  • Improving Aeromagnetic Surveying Capabilities of Uninhabited Aircraft Systems

    Resource Type:
    Thesis
    Creator:
    Cunningham, Michael
    Abstract:
    Uninhabited aircraft systems (UAS) have grown in popularity for aeromagnetic surveying. While the technology has been demonstrated to be viable, studies have not addressed three areas. First, comparisons with traditional platforms over geologically interesting regions are limited. Second, demonstrations of advanced processing with UAS data are rare. And lastly, methods for magnetic compensation of UAS data is outstanding. This thesis addresses these three areas and provide approaches to evaluate UAS performance and improve data quality. A hexacopter UAS was used to fly an aeromagnetic survey over a property with prospective gold targets. The UAS data was found to be repeatable and consistent. Qualitative and quantitative comparison with data from traditional magnetic surveys revealed that the UAS data could delineate geological structures better than the helicopter data and more efficient to collect than ground data. Unconstrained and constrained magnetic inversion demonstrated that the quality of the data collected by the UAS was sufficient to model the structural framework of banded iron formations within the survey area. It highlighted that the potential gold ore zones are not directly associated with them, but rather with steeply dipping faults that transect the area. The exercise showed that, at the early stage of exploration, performing unconstrained inversion yielded a realistic and detailed model of the subsurface, opening the possibility of implementing magnetic inversion as a continuous process during targeted high-resolution surveying for mineral exploration. Magnetic compensation of noise from aircraft attitude variations is typically modelled by performing a least-squares fit to a 16-term model by bandpass filtering data from a high-altitude (3,000 m) figure-of-merit flight. Government and hardware limitations generally prevent UAS to fly at such altitudes (over 122 m AGL), so an alternative solution was developed that uses recurrent neural networks on survey data, without the need of an FOM. The algorithm was tested on data from a traditional fixed-wing airplane survey and data from UAS flying at 120 m and 50 m above ground level. Comparisons with established compensation methods showed that the proposed algorithm could become a practical alternative.
    Thesis Degree:
    Doctor of Philosophy (Ph.D.)
    Thesis Degree Discipline:
    Earth Sciences
    Date Created:
    2022

  • The Strains of Inequality: An Exploration of the Effects of Cannabis Legalization on Black and Indigenous Peoples in Canada

    Resource Type:
    Thesis
    Creator:
    DiLoreto, Erika Irma Marie
    Abstract:
    This thesis presents the lived experiences of 19 Black, Indigenous, and white individuals in the new age of cannabis legalization within Canada, to demonstrate the long-lasting consequences of decades of drug prohibition and criminalization. As a response to the promise that legalization would bring with it racial justice, this research centres the experiences of racialized people, bringing into focus forms of inequality, prejudice and discrimination that remain intact despite changes to drug policy. To complement numerous quantitative studies on the lasting impacts of cannabis criminalization, this qualitative research explores the nuances of individual experiences of legalization among cannabis users. This research draws on broader theoretical perspectives surrounding settler colonialism, intersectionality, and race to situate both the historical and contemporary effects of cannabis prohibition.This research situates the interview findings within a critical race and cumulative disadvantage framework, using racial habitus as a conceptual tool for understanding the differences in experience.
    Thesis Degree:
    Master of Arts (M.A.)
    Thesis Degree Discipline:
    Sociology
    Date Created:
    2022

  • Identifying Opinion Based Questions in Developer Chat Communication

    Resource Type:
    Thesis
    Creator:
    Muthu Subash, Keerthana
    Abstract:
    Today, software developers work on complex and fast-moving projects that often require instant assistance. With numerous topics discussed in parallel in chat servers such as Discord, mining them would offer researchers opportunities to develop software tools and services. Firstly, we propose a dataset called DISCO consisting of the one-year public DIScord chat COnversations of four software development communities. Secondly, we improve the existing ChatEO's opinion-asking question identification process by replacing heuristics with Deep Learning (DL) architecture (with various word embeddings) in Natural Language Processing tasks. The results show a better performance of DL models over heuristics and are validated with a manual qualitative study. We have employed an automatic weak learner, Snorkel to label a larger dataset to increase DL performance. We have also used class balancing techniques - SMOTE and Near-Miss on this larger dataset. SMOTE along with Multi-CNN and GloVe-Twitter achieves the best performance in this study (0.95 recall).
    Thesis Degree:
    Master of Computer Science (M.C.S.)
    Thesis Degree Discipline:
    Computer Science
    Date Created:
    2022

  • A Theoretically and Comparatively Informed Description of Yogad Morphology

    Resource Type:
    Thesis
    Creator:
    Koren, Sarah Louise
    Abstract:
    Yogad is an Austronesian language spoken in the Northern Philippines by approximately 16,000 speakers. Previous descriptive work on Yogad follows a nonaprioristic approach, where no categories are imported from other languages. This description makes it difficult to gloss functional morphemes or to discuss Yogad in a cross-linguistic context. In this paper, I reanalyze the morphology of Yogad following a restrictivist approach to language description, particularly the verbal affixes, case marking particles, and personal pronouns. I provide a description of Yogad morphology which does not exoticize the language, is informed by theory, and can contribute to discussions and debate within the language family. I situate Yogad in the larger context of Austronesian languages through a comparative study and a diachronic discussion. I provide two descriptions of Yogad morphology, following the analyses and theories held by the two sides of the Austronesian voice debate.
    Thesis Degree:
    Master of Arts (M.A.)
    Thesis Degree Discipline:
    Linguistics
    Date Created:
    2022