Theses

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The role of perceptual load and sensory degradation on cross-modal selective attention
    The role of perceptual load and sensory degradation on cross-modal selective attention
    To understand our sensory environment, our perceptual system must employ selective attention; the ability to attend to target information while ignoring distracting information. In the uni–modal domain the main determinant of selective attention success is capacity limitation, where only when processing capacity is taxed by the target (high load; HL) is distraction eliminated (perceptual load theory; PLT). Conversely, data limits while also increasing task demands, do not benefit selective attention as these limits are often driven by sensory degradation (SD) such that placing additional resources towards the target is not beneficial. Investigations of PLT to the cross–modal domain have produced mixed results, and no study has yet directly contrasted the impact of capacity and data limits in the cross–modal domain. The present dissertation focused on examining the impact of Perceptual Load (PL) and SD on cross–modal selective attention, in addition to examining how these factors would interact with the attended modality and individual differences (ID) in attentional control. Experiment 1 used a go–no–go manipulation of PL to show that distractor effects were not reduced at HL compared to low load (LL) condition and instead displayed trends for increased distraction under HL regardless of the attended modality. Experiment 2 used the addition of noise to create SD, and found that distractor processing increased under SD, again regardless of the attended modality. Experiment 1 and 2 used a uni–modal measure of attentional control, and overall both studies did not find a consistent pattern of correlation with cross–modal selective attention, suggesting important differences between the two. Experiment 3 used a single manipulation to create HL and SD conditions in a single experiment, and also found that both HL and SD showed trends of increased distraction relative to LL conditions. Overall the current dissertation suggests that capacity limitations arise at the modality level, and so do not impact cross–modal selective attention. As such, the findings of the current dissertation suggest there is no difference between capacity and data limited conditions in the cross–modal domain. Results are interpreted within a cross–modal selective attention framework.
      
 Understanding barriers to accessing mental health services for newcomers to Canada using Peterborough, Ontario, as an illustrative example
    Understanding barriers to accessing mental health services for newcomers to Canada using Peterborough, Ontario, as an illustrative example
    The quality of an individual’s mental health has a significant impact on their quality of life, as well as on the cost to society. Regular access to mental health services can help mitigate the risk factors of developing mental illnesses. This paper examines barriers to accessing mental health services, using the community of Peterborough, Ontario, as an example. Social, economic, and cultural barriers impact help-seeking amongst immigrants, putting them at a higher risk of developing mental disorders. The social determinants of mental health can be useful when developing policies aimed at improving utilization of mental healthcare services. Policy makers need to first focus on collecting accurate information on the population, and then developing targeted solutions to eliminate barriers such as language and employment that prevent help-seeking in immigrants.
      Efficient compressed sensing reconstruction frameworks for accelerated cardiac magnetic resonance imaging
    Efficient compressed sensing reconstruction frameworks for accelerated cardiac magnetic resonance imaging
    Dynamic magnetic resonance imaging requires rapid data acquisition to provide an appropriate combination of spatial and temporal resolution, and volumetric coverage for clinical studies. In the most challenging clinical situations, conventional dynamic MR scanners are often incapable of simultaneously providing images with sufficient temporal resolution and high spatial resolution. In practice, clinicians are often forced to compromise between these parameters, often resulting in sub-optimal performance. Cardiac MRI is the most challenging and inspiring dynamic MRI application. In cardiac MRI, the main challenge is the sensitivity of reconstruction methods to large inter frame motion. The reconstructions often suffer from temporal blurring and motion related artifacts at high acceleration factors. In this dissertation, three novel approaches are proposed specifically designed to minimize the sensitivity of the reconstructions to inter frame motion. First, a compressed sensing (CS) based image reconstruction method in conjunction with spiral sampling is developed for the reconstruction of dynamic MRI data from highly accelerated / under-sampled Fourier measurements. In the second algorithm, the problem of motion artifacts including respiratory motion and cardiac motion in compressed sensing reconstructions is addressed. A motion estimation/motion compensation algorithm based on a modified search that aids block matching and results in improved residual reconstruction is incorporated into the CS reconstruction for dynamic MRI. In the third algorithm, a novel formulation for the joint estimation of the deformation and the dynamic images in cardiac cine MR imaging is introduced. The motion estimation algorithm estimates the deformation by registering the dynamic data to a reference dataset that is free of respiratory motion, which is derived from the measurements themselves. A variable splitting framework is used to minimize the objective function, and thus derive the deformation and the dynamic images. The validation of the proposed algorithms is illustrated using a numerical phantom and in-vivo cine MRI data to show the feasibility in precisely recovering cardiac MRI data from extensively under-sampled data.
      “Shall we put the heart in now?” A comparative analysis between creature features and their single reel abridgements
    “Shall we put the heart in now?” A comparative analysis between creature features and their single reel abridgements
    Single reel abridgements of commercial feature films are entering moving image archives because home movie collections that contain them are slowly increasing in archival representation. The abridged commercial films occupy a liminal space in between sustained preservation efforts that focus on studio films and the current interest paid to preserving home movies. As a result, the abridged films are being neglected. The films’ liminal status stems from a dearth of information regarding their relationship to the original films and a clear definition of what they are narratively and aesthetically. After analyzing fourteen abridged horror and science fiction films found in the Ryerson Moving Image collection and comparing them to their original counterparts this project finds that the abridged films are heavily altered in terms of narrative, characters, and causality, and should be treated as individual objects instead of derivative works, thus absolving their liminal status.
     "I realized that cops are just regular people" : changing youth attitudes toward the police through community policing
programming.
    "I realized that cops are just regular people" : changing youth attitudes toward the police through community policing programming.
    Existing literature examining youth-police relations has consistently found that willingness to engage with the police is directly influenced by youth attitudes toward the police. Research findings suggest that increasing positive attitudes toward the police among adolescent populations will result in a subsequent increase in behaviours supportive of the police and law enforcement. The current study was a mixed-method evaluation (including survey data and qualitative interviews) of a community policing pilot program designed to increase positive contact between at-risk youth and police officers. The program was effective in positively changing youth attitudes toward the police. Interview results provide evidence of a direct mechanism for increasing trust and cooperation with the police. Survey results indicate that positive contact with the police can shift general attitudes toward the police and reduce perceptions of police discrimination. Further, survey findings support the program as a remedial intervention for youth with previous negative police contact.
     (En)countering oppression: an argument for self-skepticism
    (En)countering oppression: an argument for self-skepticism
    Political philosophy has a lot to say about oppression, but does it adequately address the issue? This project asserts that it does not. The primary goal of this thesis is to redefine how we look at this socio-political problem, and to create a new model for analysis and application. I begin with a discussion of social contract theory and the many ways it has changed in an attempt to properly address the issue of oppression. Following this, the project turns towards an ethico-epistemological analysis of the elements of oppression in the modern social sphere. In this analysis, I look at prejudice, bias, disagreement, virtue, and vice as they pertain to the problem of oppression. Notably, this project considers the epistemic effects/affects of both the oppressed’s and the oppressor’s viewpoint. Finally, the project culminates in the development of the Argument for Self-Skepticism, my alternative to current social contract theory.
     A biomechanical study of a novel biomimetic hip implant.
    A biomechanical study of a novel biomimetic hip implant.
    A three dimensional finite element (FE) model of a novel carbon fibre polyamide 12 composite hip stem was used to compare with two commerically available (Exeter and Omnifit) hip stems to minimize stress shielding and bone resorption. A virtual axial load of 3000N was applied to the FE model which replicated the experimental study. Strain and stress distributions were computed and compared with experimental results. Experimentally, three hip stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. From the FE analysis, the von mises stress range for the composite hip stem was 200% and 45% lower than that in the Omnifit and Exeter implants, respectively. The aggregate average difference between FE and experimental microstrains for four proximal strain gauge locations were 7.5% (composite), 11.5% (Exeter), 14.6% (Omnifit), and the composite hip stem's stiffness (1982N/mm) was lower than the metallic hip stem stiffnesses (Exter, 2460N/mm; Omnifit, 2543 N/mm). This study showed considerable improvement in stress transfer to bone tissue.
     A case study on most optimal power flow solutions to supply power to a new residential compound load located at
  the outskirts of an industrial area by using the optimization tools
    A case study on most optimal power flow solutions to supply power to a new residential compound load located at the outskirts of an industrial area by using the optimization tools
    This project studies different solutions, presents an efficient and reliable approach, to solve the optimal power flow (OPF) problem for an industrial power system by using fmincon optimization method and technique. This fmincon toolbox from MATLAB attempts to find a constrained minimum of a scalar function of several variables starting at an initial estimate. This is generally referred to as constrained nonlinear optimization or nonlinear programming. The objective in OPF problem is to minimize the total cost function of generating units and the transmission losses, while maintaining the design and performance of the entire power system, satisfying the operational requirements such as the real and reactive power outputs of the generating units, bus voltages and power flow of transmission lines…etc. This project presents the most optimal solution of power flow incorporating wind generation cost, to supply power to a new domestic load located at the outskirts of an industrial area for three different scenarios. This residential is typical of long rural line with isolated load area. The challenge in our case study is to incorporate a wind generation unit as one type of green energy, that are currently being considered as an alternative source of power, to feed this long rural line for the domestic load without effecting in the total generation cost. A case study is carried out for three different scenarios incorporating wind generation cost. The results of OPF in this project shows that incorporating wind generation unit as renewable energy source with the entire power system will have a minimum generation cost and minimum transmission losses for the entire power system even if the wind generation cost assumed to be the most expensive one comparing with other conventional generation units. This project report provides implementation of Algorithm for the entire power load flow using the fast decoupled power flow (FDPF) and optimizes the best solution for the three different scenarios by using fmincon Interior Point Algorithm as one of optimization toolbox to achieve the minimum total cost function of generating units and minimum transmission losses.
     A multi-objective optimization analysis of passive energy conservation measures in a Toronto house.
    A multi-objective optimization analysis of passive energy conservation measures in a Toronto house.
    This study presents a multi-objective optimization environment in which passive energy conservations measures of a high performance house in Toronto are evaluated. The optimization environment was created using the jEPlus software suite where the case study house acted as the reference building. The study house simulation model was calibrated using a data-driven procedure, and acceptable CV(RSME) and NMBE tolerances were reached in accordance with ASHRAE calibration requirements. The optimization varied passive energy efficiency parameters in search of configurations yielding optimal building performance and life cycle cost. The optimization results showed that energy savings of 33% relative to building code minimum were justified at the point of minimal life cycle cost via passive energy saving measures alone before considering active systems. These results suggest that improved thermal envelopes are economically advantageous with good building practice. However, they suggest that the current Passive House standard does not coincide with the economic minimum for the local economic and environmental climate.
     Accuracy improvement of SOC estimation in lithium-ion batteries by ANFIS vs ANN modeling of nonlinear cell characteristics
    Accuracy improvement of SOC estimation in lithium-ion batteries by ANFIS vs ANN modeling of nonlinear cell characteristics
    Over the last century, the energy storage industry has continued to evolve and adapt to changing energy requirements. To run an efficient energy storage system two points must be considered. Firstly, precise load forecasting to determine energy consumption pattern. Secondly, is the correct estimation of state of charge (SOC). In this project there is a model introduced to predict the load consumption based on ANN implemented by MATLAB. The Designed intelligent system introduced for load prediction according to the hypothetical training data related to two years daily based load consumption of a residential area. For another obstacle which is accurate estimation of SOC, two separate models are provided based on ANN and ANFIS for Lithium-ion batteries as an energy storage system. There are several researches in this regard but in this project the author makes an effort to introduce the most efficient based on the MSE of each performance and as a result the method by ANN is found more accurate.
     An examination of environmental instruments to promote sustainable tourism development for Savusavu, Fiji
    An examination of environmental instruments to promote sustainable tourism development for Savusavu, Fiji
    This study explores the opportunity to implement environmental instruments to promote sustainable tourism development. Environmental instruments are tools, regulations and strategies that can improve the sustainability of a destination. This study was based on ideas from Governing the Commons Theory and Stakeholder Theory, which suggests sustainable development can be achieved by including stakeholders to form collective management and avoid natural resource tragedies. The study uses face-to-face, semi-structured interviews with stakeholders (n=41) to explore environmental instruments to implement in Savusavu, Fiji -- a small island developing state (SIDS). The study identified lack of waste management, education and participation amongst stakeholders and the island’s susceptibility to climate change as the key issues the destination faces in developing a sustainable tourism industry. The study recommends implementing a voluntary fund, environmental education and stakeholder participation instruments to promote sustainable development in Savusavu.
     Analysis of the impacts of extreme weather events on Ontario’s electricity grid using agent-based modeling
    Analysis of the impacts of extreme weather events on Ontario’s electricity grid using agent-based modeling
    Extreme weather events have increased and are causing severe impacts on the electricity grid. Heat waves and ice storms are becoming more intense and frequent in Ontario, Canada. During an extreme weather event, the electricity demand fluctuates and the reliability of the electrical grid decreases due to equipment failure and shortage of electricity supply, which leads to blackouts. An initial stage simulation model is developed using the computational technique agent-based model. This thesis analyzed the impact of extreme weather events based on severity and frequency levels on two sector of Ontario’s electricity grid which are generation plants and distribution network. The simulation output showed multiple grid failures in different regions during extreme severity levels and increased frequencies of weather events. The model also showed heat waves and ice storms resulting differently depending on the month, extreme temperature months were more prone to failures than average temperature months.