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.

Design and fabrication of high-performance capacitive micro accelerometers

Author: 
Date created: 
2018-02-22
Abstract: 

This thesis presents the development of capacitive high-performance accelerometers for sonar wave detection. Two different designs of in-plane and out-of-plane accelerometers are developed, micro-fabricated, and experimentally tested.The out-of-plane accelerometer is designed based on a continuous membrane suspension element. In comparison to beam-type suspension elements, the new design provides uniform displacement of the proof mass, lower cross-axis sensitivity, and lower stress concentration in suspension elements which could result in higher yield in the fabrication process. The out-of-plane accelerometer is fabricated using a novel microfabrication method which facilitates developing continuous membrane type suspension elements and full wafer thick proof mass for accelerometers. The designed accelerometer is fabricated on a silicon-on-insulator wafer with an 8 µm device layer, 1.5 µm buried-oxide layer, and 500 µm handle wafer. The developed accelerometer is proven to have resonance frequency of 5.2 kHz, sensitivity of ~0.9 pF/g, mechanical noise equivalent acceleration of less than 450 ng/√Hz, and an open loop dynamic range of higher than 130 dB while operating at atmospheric pressure.The in-plane single-axis accelerometer is designed based on a proposed mode-tuned modified structure. In this modified structure, the proof mass is substituted with a moving frame which also provides the area for increasing the number of sensing electrodes. This substitution contributes to widening the bandwidth of the accelerometer by locating the anchors and elastic elements both inside and outside of the moving frame. The designed accelerometer is fabricated on a silicon-on-insulator wafer with a 100µm device layer and high aspect ratio capacitive gaps of ~2 µm. The sensitivity of the accelerometer is measured as ~0.7 pF/g with the total noise equivalent acceleration of less than 500 ng/√Hz in the flat band region of the bandwidth. The resonance frequency of the devices is 4.2 kHz while maintaining a linearity of better than 0.7%. The open loop dynamic range of the accelerometer, while operating at atmospheric pressure, is higher than 135 dB, and the cross-axis sensitivity is less than -30 dB.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Behraad Bahreyni
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) Ph.D.

Cu7 me7 q’wele’wu-kt. "Come on, let's go berry-picking". Revival of Secwepemc wellness approaches for healing child and youth experiences of violence

Date created: 
2018-01-18
Abstract: 

This dissertation is part of an intergenerational genealogy of Secwepemc and Indigenous feminist resistance to colonial violence and, more importantly, of the repudiation of state-sanctioned approaches through the construct of “trauma” and instead the avowal and resurgence of Secwepemc laws, practices, and processes. This thesis shares stories from my research with 11 multigenerational Secwepemc and Indigenous healers working with Secwepemc and Indigenous children and youth in Secwepemculecw, the land of the Secwepemc people. Through the methodological framework of Steseptekwle-Secwepemc storytelling, together with the theoretical framework of Red Intersectionality, these stories illuminate the ongoing resistance to colonial power, but also demonstrate the ways in which we are reinstating our Secwepemc child wellbeing and healing praxis through everyday acts of decolonial love, relationship and kinship. Along with the stories of the healers interviewed, this research co-constructs a birch bark basket of decolonial knowing rooted in Secwepemc teachings and practices. This basket also holds the theoretical framework of Red Intersectionality (Clark, 2012; Clark, 2016), an Indigenous feminist and holistic model that follows in the tireless tradition of Indigenous and Black feminist theorizing of love, rage, desire, resistance, and creative regeneration as the foundation from which to challenge violence against Indigenous children and youth. In doing so together, the stories reveal and amplify Indigenous agency while refusing the colonial gaze, which assumes and demands Indigenous people are in need of help or saving. Ultimately this dissertation functions to crack open the interstitial spaces of the colonial arteries of violence and the broken narratives of risk, and instead reveals the deeper practices of witnessing each other and our children in this work.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Olena Hankivsky
Department: 
? by Home Dept & Faculty of Senior Supervisor: Special Arrangements
Thesis type: 
(Thesis) Ph.D.

Books

Date created: 
2018-01-29
Abstract: 

Books, conceived and directed by Patrick Blenkarn, is a performance with and about books. Over 70min, four performers perform a series of tasks with books upon an empty stage. In the process, they sculpt an encounter of ideas and images: of chaos, of devotion, of exhaustion, of knowledge.

Document type: 
Graduating extended essay / Research project
Senior supervisor: 
Cole Lewis
Department: 
Communication, Art & Technology: School for the Contemporary Arts
Thesis type: 
(Project) M.F.A.

Elucidating the physiological adaptation of loss of retinoblastoma protein in conjunction with hypoxia in neuroblastoma cells.

Author: 
Date created: 
2017-06-22
Abstract: 

Neuroblastoma is a malignancy of multipotent embryonic neural crest cells and is the most common cancer in infancy. Since neuroblastoma tumours originate from immature sympathetic cells called neuroblasts, the effect of hypoxia on these cells is of great significance. Low oxygen pressure (hypoxia) is a physiological condition that facilitates increased malignancy and tumour progression in several solid cancers. Hypoxia Inducible factors (HIF)-1 and HIF-2 and their dimerization partner TRIP230 are the principle transcriptional regulators of the hypoxic response. Our group has previously shown that the tumour suppressor retinoblastoma protein (Rb) acts as a transcriptional repressor of hypoxia by its ability to associate with HIF-1. The role of loss of Rb in facilitating the hypoxia related-genetic programs has yet to be studied in neuroblastoma. We used CRISPR-Cas9 technologies to genetically knock-out Rb expression in two non MYCN amplified neuroblastoma cell lines, SH-SY5Y and SK-N-AS. We used a microarray platform to compare the steady-state expression levels of mRNA from these two cell lines to determine aberrant expression of hypoxia related genetic programs that increase cell motility and invasion and promote metastasis. Using migration assays, qRT-PCR and Western blot analysis we have identified multiple genes whose expression is significantly upregulated with the loss of Rb in conjunction with hypoxia. The identification and characterization of these genes could provide the basis for developing novel therapies and new diagnostic markers for treatment for children with non-MYCN amplified neuroblastoma.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Timothy Beischlag
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.Sc.

Virtual friction: Networking sexuality and HIV prevention in the digital age

Author: 
Date created: 
2017-12-06
Abstract: 

From advances in HIV prevention science bringing us pre-exposure prophylaxis (PrEP) to the proliferation of hook-up apps like Grindr, the late 20th/early 21st centuries have introduced intense socio-technical transformations in gay men’s intimate lives. In particular, the networked decentralization and privatization of sexuality has generated a corresponding set of discourses within gay men’s communities and in the social world of HIV prevention. Community narratives either construct the Internet as a virtual community where acceptance, solidarity, friendship, romance, and sex become easily accessible in a largely hetero-normative world, or a virtual bathhouse accelerating the depoliticization and commodification of gay life (Kapp, 2011; Ward & Arsenault, 2012). In public health, accounts oscillate between exploring the Internet’s potential to revitalize HIV prevention efforts (Chiasson et al., 2009; Rhodes et al., 2011; Rosser et al., 2010), and debating its possible role in facilitating HIV risk and transmission (Berry et al., 2008; Bull & McFarlane, 2000; Wohlfeiler & Potterat, 2005). Intersecting perspectives from communication, Internet studies, and public health, this dissertation traces the erotic and epidemiological contours of a “network society” (Castells, 1996) where the Internet plays an ambivalent role in social life. Based on archival research, personal experience, and 31 interviews with gay men, public health actors, and Internet entrepreneurs in San Francisco and Vancouver, this project uses the concept of virtual friction to think through the tensions, contradictions, and paradoxes that characterize the networking of sexuality and HIV prevention in the digital age. Broadly speaking, I ask whether and how the Internet has transformed sexuality and HIV prevention by examining the discourses, subjectivities, and practices that have emerged, as well as the subsequent set of opportunities and challenges they generate for the various social worlds involved (Strauss, 1978). I argue that virtual friction is not only an inevitable but necessary part of the process because it renders visible the limits of imagining social problems and solutions in purely technological terms. Friction challenges us to acknowledge the competing epistemologies, interests, and perspectives that underpin life in the digital age, taking us out of our comfort zones by asking how we know and believe what we do about science, technology and society.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Peter Chow-White
Department: 
Communication, Art & Technology: School of Communication
Thesis type: 
(Thesis) Ph.D.

Hand Gesture Identification in Older Adults using Force-Myography

Author: 
Date created: 
2017-06-20
Abstract: 

The projected increase in the proportion of seniors in society has prompted the growth of senior-technologies that support aging-in-place. The aim of this thesis to explore the suitability of Force Myography (FMG) for hand gesture identification in aging populations to complement other technologies that promote aging-in-place and to investigate the practical considerations for implementation. Characteristics of using FMG with seniors (aged 60+ years old) was first determined with a protocol involving five seniors and five non-seniors. Participants were invited to don a custom FMG device and perform a series of stationary hand gestures while being guided by a virtual user interface. The interface provided online image instructions of the required gesture, as well as visual feedback of successful gesture identification. Participants also performed household activities based tasks in a self-selected manner. On average, seniors completed specified hand gestures within 1.4 seconds of online instruction, with inadvertent identification of control gestures during household tasks lasting at most 1.45 seconds. Although these times were comparable non-senior participants, seniors demonstrated increased variability. Lastly, online accuracies for gesture classification only reached 75% compared to the 91% of non-senior participants. Considering the results of the first study, a follow up study was performed with a larger recruitment pool focusing on intrinsic user features that influence the variability in FMG acquisition and modelling. The results demonstrate that age and gender associated differences in band tightness, grip strength and ratio of skinfold thickness to forearm circumference account for at most 30% of the variability in FMG responsiveness, translating to 7% to 30% of the variability of model test accuracy. Intrinsic user features also influenced the severity that functional noise (the affect of unintended movements) had on classification. Results also revealed that variables independent of the user, such as band removal, contribute significantly to declines in testing accuracy, where declines ranged from 28% to 96%. Finally, results also showed that methods of FMG modelling typically encountered in the literature shows limited effectiveness during non-static activity.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Carlo Menon
Department: 
Applied Sciences: School of Engineering Science
Thesis type: 
(Thesis) M.A.Sc.

“Grey matter”: The challenge of maintaining harmonic consistency and thematic ambiguity in the age of artificial intelligence

Author: 
Date created: 
2018-05-28
Abstract: 

“Grey Matter”, a forty-two minute, 4-movement suite for string quartet and Disklavier (Yamaha’s automated piano), ambiguously explores themes of aging (and the body’s attendant neural/psychic deterioration and social alienation) in the age of automation, digital technology and artificial intelligence. Another thematic layer implies the following questions: will the roles of creative and performing artists become obsolete, like so many other professions are feared to become, with accelerating automation and artificial intelligence? Is technology bestowing upon us a utopian or dystopian future? Conceived with symmetrical harmonic processes, the work layers and juxtaposes sequentially diminishing harmonies (and diminishing performance personnel) with contrapuntal procedures. Alluding to a wide range of historical sources as disparate as Joseph Haydn, Robert Schumann, Béla Bartók, Charlie Chaplin, Kurt Vonnegut, Lee “Scratch” Perry and Spike Jonze, “Grey Matter” culminates with a collage of Bachian and Lisztian materials feeding back and reverberating through circular 4-channel electroacoustic diffusion.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Arne Eigenfeldt
Department: 
Communication, Art & Technology: School for the Contemporary Arts
Thesis type: 
(Project) M.F.A.

Generating natural language summary for image sets

Author: 
Date created: 
2018-05-31
Abstract: 

We address the problem of summarizing an image set with a natural language caption. We present PlacesCap, a new dataset for image set summarization. Our dataset consists of 11,661 image sets with a total of 116,113 images, where each set is summarized by a 3 sentence caption. We propose novel pooling operators for permutation invariant sets of feature maps, and empirically evaluate image set summarization models based on those operators. We also conduct experiments of image set classification and show competitive performance for the proposed set pooling operators.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Greg Mori
Department: 
Applied Sciences: School of Computing Science
Thesis type: 
(Thesis) M.Sc.

Experiencing mathematics through problem solving tasks

Date created: 
2018-05-07
Abstract: 

Learning through problem solving is an old concept that has been redeveloped as a valuable strategy to teach mathematics. Many teachers feel a tension between the value of teaching through problem solving and the necessity of teaching a prescribed curriculum , often resulting in minimizing the time students spend on genuine problem solving. The purpose of this thesis was to investigate the extent that a mathematics student encounters curriculum while working freely on problem solving tasks. A student in a Pre Calculus and Foundations Math 10 course, which already had a culture of thinking and problem solving, was observed for a 1-month period to see what mathematical content they engaged with through problem solving. Observations, photographs, and notes were taken about the tasks and the mathematics that the student encountered during problem solving each day. The variety of tasks was very broad to prevent students from assuming a problem solving strategy based a current unit of study. Through analysis of the content one student engaged with, it was found that almost the entirety of the Pre Calculus and Foundations 10 prescribed learning outcomes was encountered in addition to both a review of some curricular content from Math 6 through Math 9, as well as exposure to curricular content from Math 11 and 12.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Peter Liljedahl
Department: 
Education: Education
Thesis type: 
(Thesis) M.Sc.

Towards the development of a sub 500 micron thermally actuated scanning fiber endoscope for detection of lung cancer

Date created: 
2018-05-30
Abstract: 

Medical professionals increasingly rely on endoscopes to carry out many minimally-invasive procedures on patients in order to safely examine, diagnose and treat a myriad of conditions. However, their distal tip size dictates which passages of the body they can be inserted into and consequently what organs they can access. For inaccessible areas and organs, patients are often subjected to intrusive, risky and uncomfortable procedures; diagnosis of lung cancer is one of these cases. Hence, this study sets out to design an endoscope head that has an outer diameter of less than 500 microns, small enough to be inserted into the lungs. To attain this goal, a novel approach based on resonance thermal excitation of a dual clad single mode optical fiber at a location close to its base is proposed. The previously obtained analytical models for describing the lateral vibratory motion of the fixed-free micro-cantilever are used to validate the corresponding physical prototypes. Parameters such as choice of materials, resonance frequency, bonding methods, shape and dimensions of the actuator bridge, structural rigidity, assembly are considered in the physical design of the device. Lateral free-end deflection of the center fiber is used as a benchmark for evaluating performance. The results show that this novel proposal can be used to satisfy the project requirements.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Carlo Menon
Department: 
Applied Sciences: School of Engineering Science
Thesis type: 
(Thesis) M.A.Sc.