Theses, Dissertations, and other Required Graduate Degree Essays

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This collection contains digitized SFU theses except for those theses submitted within the last 12 months. If you cannot find the thesis you are looking for please search Recently Submitted Theses as it may be a recently submitted thesis and thus not yet available in Summit.

Expressive movement generation with machine learning

Author: 
Date created: 
2021-03-25
Abstract: 

Movement is an essential aspect of our lives. Not only do we move to interact with our physical environment, but we also express ourselves and communicate with others through our movements. In an increasingly computerized world where various technologies and devices surround us, our movements are essential parts of our interaction with and consumption of computational devices and artifacts. In this context, incorporating an understanding of our movements within the design of the technologies surrounding us can significantly improve our daily experiences. This need has given rise to the field of movement computing – developing computational models of movement that can perceive, manipulate, and generate movements. In this thesis, we contribute to the field of movement computing by building machine-learning-based solutions for automatic movement generation. In particular, we focus on using machine learning techniques and motion capture data to create controllable, generative movement models. We also contribute to the field by creating datasets, tools, and libraries that we have developed during our research. We start our research by reviewing the works on building automatic movement generation systems using machine learning techniques and motion capture data. Our review covers background topics such as high-level movement characterization, training data, features representation, machine learning models, and evaluation methods. Building on our literature review, we present WalkNet, an interactive agent walking movement controller based on neural networks. The expressivity of virtual, animated agents plays an essential role in their believability. Therefore, WalkNet integrates controlling the expressive qualities of movement with the goal-oriented behaviour of an animated virtual agent. It allows us to control the generation based on the valence and arousal levels of affect, the movement’s walking direction, and the mover’s movement signature in real-time. Following WalkNet, we look at controlling movement generation using more complex stimuli such as music represented by audio signals (i.e., non-symbolic music). Music-driven dance generation involves a highly non-linear mapping between temporally dense stimuli (i.e., the audio signal) and movements, which renders a more challenging modelling movement problem. To this end, we present GrooveNet, a real-time machine learning model for music-driven dance generation.

Document type: 
Thesis
Supervisor(s): 
Philippe Pasquier
Department: 
Communication, Art & Technology: School of Interactive Arts and Technology
Thesis type: 
(Thesis) Ph.D.

Stabilizing proton exchange membranes using Cerium(III) ions

Author: 
Date created: 
2021-10-05
Abstract: 

Proton Exchange Membrane Fuel Cells (PEMFCs) represent an innovative and promising technology for transportation applications due to their low weight, lower operative temperature, and pressure ranges. One of the most challenging limiting factors for the adoption of PEMFC in everyday life is the durability of the Proton Exchange Membrane (PEM), the true core of this type of device. The internal environment of PEMFCs is naturally rich in free radicals (such as HO• and HOO•), which react with the PEM backbone, damage the PEM, and ultimately lead to the PEMFC failure. One way to improve the stability of PEMs against these species is the incorporation of an additive that can act as a radical scavenger and become the preferential site for radical oxidation. One of the most used radical scavengers for this kind of application is cerium in its Ce3+ oxidation state. In this thesis work, a set of sulfophenylated polyphenylenes (sPPB) membranes were synthesized by introducing different amounts of Ce3+ (sPPB-Ce3+), and efforts were made to identify the multiple degradation pathways (chemical, thermal, mechanical). The stability of sPPB-Ce3+ membranes to radical degradation was enhanced almost threefold, they maintained their structural integrity, shape, and thickness and their proton conductivity was comparable to that of the pristine materials. Several other properties such as dimensional stability, polydispersity and solubility also underwent important changes. As observed through these analyses, the effects of Ce3+ on the original material properties can be advantageous in improving the characteristics of proton exchange membranes.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Steven Holdcroft
Department: 
Science: Department of Chemistry
Thesis type: 
(Thesis) M.Sc.

Documentary as alternative practice: Situating contemporary female filmmakers in Sinophone cinemas

Date created: 
2021-08-17
Abstract: 

Women’s documentary filmmaking in Sinophone cinemas has been marginalized in the film industry and understudied in film studies scholarship. The convergence of neoliberalism, institutionalization of pan-Chinese documentary films and the historical marginalization of women’s filmmaking in Taiwan, Hong Kong, and the People’s Republic of China (PRC), respectively, have further perpetuated the marginalization of documentary films by local female filmmakers. The orientalizing gaze from the global north does not take into account local women’s struggle in the industry whereas the local male-dominant industry in each region is strongly tied to and upheld by different discourses of nationalism. By addressing multiple layers of hegemony, my research examines the local and global impact on female documentary filmmakers in the above three regions since the 1980s and the ways in which they adjust their modes of production while continuing in their works to resist dominant ideologies that have shaped mainstream national/regional film culture. Drawing from production studies and feminist film criticism, I point out that each production trajectory reflects changing political systems, institutions and resources available over time. Female documentary filmmakers’ interpretative and communicative power have rewritten the traditionally male-dominant and neo-national narratives of film history and industry. Since the 1980s, Taiwanese female documentary filmmakers have carved out alternative representations during a time when defining the meaning of a national cinema was an urgent task. Hong Kong female documentarians share a consistently radical and humanistic concern regarding gender and ethnic diversity without resorting to political or cultural essentialism or antagonism. Documentary films by women in the PRC expose the incongruence between the state’s agenda and the lived reality of Chinese women. Sinophone female documentarians’ radical resistance does not only reside in their works but in their filmmaking practices, which foreground the periphery as the site in which place-based and community-based stories and identities are shaped and told.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Helen Hok-Sze Leung
Department: 
Arts & Social Sciences: Department of Gender, Sexuality, and Women's Studies
Thesis type: 
(Thesis) Ph.D.

Financialization and development regime building in waterfront redevelopment in Chinese port cities under neoliberalism: A case study of Qingdao Olympic Sailing Centre

Author: 
Date created: 
2021-08-05
Abstract: 

Post-industrial waterfront redevelopment refers to the transformation from the Keynesian-Fordist industrial landscape to the post-industrial service-based waterfront (Vormann, 2014). Neoliberal financial devolution has empowered local development coalitions to tap into local financial resources by leveraging private investment. Coalitions made up of city hall and private sector actors may be considered as urban development regimes that can utilize their institutional resources to make potent governing decisions (Stone, 1989).This research focuses on the financing of waterfront redevelopment projects in Chinese port cities under neoliberalism. The study examines Qingdao Olympic Sailing Centre as an example of how such urban development coalitions function to promote waterfront redevelopment projects, and by extension, to understand how post-industrial waterfront redevelopment is pursued in Chinese port cities. In addition to the Sailing Centre, the relocation of Beihai Shipyard exemplifies how post-industrial waterfront redevelopment, in conjunction with the effect of gentrification, shapes the neoliberal urban landscape. The financing story of the Qingdao Olympic Sailing Centre is explored as a case study of entrepreneurial urban redevelopment strategy, and this study uncovers the process to present how an urban development coalition extracts land value from entrepreneurial strategies amid the trend of neoliberalism. How the Chinese urban growth coalitions, made up of the local city halls and private developers, conduct city redevelopment projects in an entrepreneurial way via mobilizing market elements and land resources to avoid the conventional budget public financing has been missing in past literature. Hence, the discussion about the financing of the waterfront redevelopment projects in the second-tier Chinese port cities contributes to filling the literature gap of how the second-tier Chinese cities conduct great-mega projects through off-budget financial instruments.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Peter Hall
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) Ph.D.

Molecular fingerprinting of VNUT-containing compartments in Neuro-2a cells

Author: 
Date created: 
2021-09-17
Abstract: 

Vesicular ATP release is involved in regulating biological processes like nociception, blood glucose, and vascular tone. ATP-containing vesicles are filled by the vesicular nucleotide transporter (VNUT) and are molecularly distinct from catecholaminergic vesicles of sympathetic neurons. This work sought to identify the molecular fingerprint of VNUT-containing vesicles. Fluorescence microscopy in Neuro-2a, HeLa, and HEK293 cells showed VNUT being widely dispersed throughout the cells with a perinuclear enrichment. VNUT failed to colocalize with known markers of synaptic vesicles, lysosomes, dense cored vesicles, and catecholaminergic vesicles. Bioinformatic analyses of mammalian VNUT C-terminus identified a unique KDEL-like HEDL motif, as well as a lack of classic synaptic vesicle-targeting dileucine-like and tyrosine-based motifs. This work suggests that VNUT likely resides primarily in the Golgi-ER complex, a previously unconsidered location for what is thought to be a vesicle-associated translocase.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Damon Poburko
Department: 
Science: Department of Biomedical Physiology and Kinesiology
Thesis type: 
(Thesis) M.Sc.

Where teachers teach: Portraits of arts educators and their classrooms

Author: 
Date created: 
2021-04-21
Abstract: 

As an Arts based educator, I am particularly interested in exploring Arts classrooms. Places tailored for teaching the Arts are so unique—they are unlike regular classrooms that have no specific purpose other than teaching students. I am so inspired when I enter pedagogically invigorating environments that educators create for their students; I feel their creativity and the excitement all around the room. Such creative potential. For this inquiry, I explored an array of Arts areas: Visual Arts, Music, Drama, Creative Writing, and Dance. Each have somewhat predictable attributes that pertain to the medium, but each hold their own individual personalities. Although the rooms themselves were radically different, each radiated the heart and dedication of the educator, each space came to signify the educator’s commitment to learning. My thesis is a series of portraits of arts teachers, their classrooms, and our encounters.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Lynn Fels
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) M.A.

The roles of ectotherm physiology and habitat use with changing water availability

Author: 
Date created: 
2021-04-20
Abstract: 

Environmental regimes are shifting with accelerating climate change, putting at risk species whose ecology has been shaped by pre-industrial climates. Both species physiology and habitat associations are central to many predictions of future climate risk. Here I focus on the role of water, both in terms of ectotherm physiology through water loss, and as habitat essential for many amphibian life histories. In Chapter 1, I explore whether amphibian and squamate thermal safety margins are mediated by species’ propensity for water loss. In Chapter 2, I combine estimates of species’ habitat use and the hydrologic suitability of wetland habitats to predict how drying from climate change may drive future habitat loss in alpine regions of the US Pacific Northwest. This work indicates that water loss has been critical to shaping species’ physiology, and that water availability as critical habitat is central to species’ persistence across alpine landscapes in the future.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Wendy Palen
Department: 
Science: Biological Sciences Department
Thesis type: 
(Thesis) M.Sc.

Access to transportation and food for users of non-profit food hubs in the City of Vancouver before and during the COVID-19 crisis

Date created: 
2021-04-09
Abstract: 

Food that is available yet inaccessible cannot ensure urban food security. This study involved an online survey (n=84) and semi-structured follow-up key informant interviews (n=10) with individuals at least 19 years old who accessed food at a non-profit food hub located in the City of Vancouver more than once before and during the COVID-19 crisis. Data from the survey and interviews highlight which individuals and families access non-profit food hubs in the City of Vancouver, how they access them, and what barriers they face to access them. Drawing from the findings, a few recommendations are provided in terms of potential ways to increase the accessibility of food at non-profit food hubs in the City of Vancouver. This study emphasizes how the current two-tier food system perpetuates stigma and harms the well-being of marginalized populations in the City of Vancouver in their journey to obtain food.

Document type: 
Graduating extended essay / Research project
File(s): 
Supervisor(s): 
Tammara Soma
Department: 
Environment: School of Resource and Environmental Management
Thesis type: 
(Project) M.R.M. (Planning)

Modelling and engineering artificial burnt-bridge ratchet molecular motors

Author: 
Date created: 
2021-04-23
Abstract: 

Nature has evolved many mechanisms for achieving directed motion on the subcellular level. The burnt-bridge ratchet (BBR) is one mechanism used to accomplish superdiffusive motion over long distances via the successive cleavage of surface-bound energy-rich substrate sites. The BBR mechanism is utilized throughout Nature: it can be found in bacteria, plants, mammals, arthropods (for example Crustaceans and Cheliceratans), as well as non-life forms such as influenza. Motivated to understand how fundamental engineering principles alter BBR kinetics, we have built both computer models and synthetic experimental systems to understand BBR kinetics. By exploring the dynamics of BBRs through simulation we find that their motor-like properties are highly dependent on the number of catalytic legs, the distance that the legs can reach from the central hub, and the hub topology. We further explore how design features in the underlying landscape affect BBR dynamics. We find that reducing the landscape from two- to one-dimensional increases superdiffusivity but leads to a loss in processivity. We also find that landscape elasticity affects all motor-like dynamical properties of BBRs: there are different optimal stiffnesses for distinct dynamical characteristics. For a spherical-hub BBR, speed, processivity, and persistence length are optimized at high, intermediate and soft stiffnesses, respectively, while rolling is also optimized at a high surface stiffness. Towards our development of a novel micron-sized protein-based BBR in the lab, we develop a new surface chemistry passivation technique and apply it to the surface of nanowires, turning an array of waveguiding nanowires into a high-throughput biosensing assay. In a separate assay, our protein-based BBR, which we call the lawnmower, is implemented in two dimensions on glass cover slips prepared with our surface chemistry (which serves as the lawn). We find the lawnmower dynamics reproduce key observations found in other similar systems, such as saltatory motion and broadly varying anomalously diffusive behaviour. The successful implementation of the lawnmower marks the first demonstration of an artificial protein-based molecular motor.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Nancy Forde
Department: 
Science: Department of Physics
Thesis type: 
(Thesis) Ph.D.

DEEMD: Drug efficacy estimation against SARS-CoV-2 based on cell morphology with deep multiple instance learning

Date created: 
2021-04-19
Abstract: 

Background: Drug repurposing can accelerate the identification of effective compounds for clinical use against SARS-CoV-2, with the advantage of pre-existing clinical safety data and an established supply chain. RNA viruses such as SARS-CoV-2 manipulate cellular pathways and induce reorganization of subcellular structures to support their life cycle. These morphological changes can be quantified using bioimaging techniques. Methods: In this work, we developed DEEMD: a computational pipeline using deep neural network models within a multiple instance learning (MIL) framework, to identify putative treatments effective against SARS-CoV-2 based on morphological analysis of the publicly available RxRx19a dataset, This dataset consists of fluorescence microscopy images of SARS-CoV-2 non-infected cells and infected cells, with and without drug treatment. DEEMD first extracts discriminative morphological features to generate cell morphological profiles from the non-infected and infected cells. These morphological profiles are then used in a statistical model to estimate the applied treatment efficacy on infected cells based on similarities to non-infected cells. Results: DEEMD is capable of localizing infected cells via weak supervision without any expensive pixel-level annotations. DEEMD identifies known SARS-CoV-2 inhibitors, such as Remdesivir and Aloxistatin, supporting the validity of our approach. Conclusions: DEEMD is scalable to process and screen thousands of treatments in parallel and can be applied to other emerging viruses and data sets to rapidly identify candidate antiviral treatments in the future.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Maxwell Libbrecht
Ghassan Hamarneh
Department: 
Applied Sciences: School of Computing Science
Thesis type: 
(Thesis) M.Sc.