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.

Heroin Use, Traumatic Brain Injury, and Schizophrenia Predict Everyday and Social Functioning in Marginally Housed Persons: Direct Effects and Mediation by Neurocognition

Author: 
Date created: 
2016-11-14
Abstract: 

Multimorbid illness, including substance use, psychiatric illness, viral infection, and traumatic brain injury (TBI), is prevalent in marginally housed persons, but it is unclear how these problems influence everyday and social functioning. We conducted mediation analyses in 210 participants in order to evaluate the effects of substance use, psychiatric illness, viral infection, and traumatic brain injury on predicting 6-month follow-up ratings of functioning, and to examine whether neurocognitive performance significantly mediated the relationship between these health characteristics and ratings of functioning. Neurocognition, alongside positive and negative symptoms, explained 47% of the effect of schizophrenia on functioning and 11% of the effect of TBI on functioning. Additionally, greater heroin use frequency was significantly associated with lower ratings of functioning, but this effect was not mediated by neurocognition. Our findings highlight the role of neurocognition in mediating the relationship between illness and functioning in the marginally housed, and inform treatment targeting toward specific morbidities in populations with complex health issues.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Allen Thornton
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Focal Point: Analyzing the Shift Of Focus When Prototyping

Date created: 
2016-12-02
Abstract: 

Prototypes are at the core of many interaction design projects. They not only allow designers to formally evaluate their design, but also to explore their project's design space, generate ideas, and discover new design opportunities. This requires the designer to engage in a reflective conversation with her prototypes - closely listening for feedback, combining ideas, and discovering new qualities. This thesis analyzes the prototypes developed for an outdoor light installation, the Urban Data Posts, in order to gain a better understanding of the interplay between designer and prototype. Using a framework to track intentionality and unintentionality in prototypes, this thesis aims to understand how individual prototypes informed the design process and the final design of the Urban Data Posts project. This will provide a better understanding of what prototypes do and exemplify what impact unintentionality in prototypes can have in design. The main contribution of this research is the Focus Framework, which captures intentional as well as unintentional design aspects in a prototype.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ron Wakkary
Department: 
Communication, Art & Technology: School of Interactive Arts and Technology
Thesis type: 
(Thesis) M.A.

Mechanisms of attentional processing during visual search: how distraction is handled by the brain

Author: 
Date created: 
2016-11-23
Abstract: 

In order to effectively search the visual environment, an observer must continually locate objects of interest amid an abundance of irrelevant and distracting stimuli. These visual distractors can sometimes inadvertently attract attention to their locations, even when an observer is attempting to search for an entirely different object. To deal with visual distractors, it has been well established that the visual system can implement a suppression mechanism to filter out irrelevant stimuli. Within the past decade, event-related potential (ERP) recordings have isolated an attentional component that is thought to reflect this suppressive processing. This ERP component—termed the distractor positivity (PD)—has been used to demonstrate that the sensory processing of irrelevant information can be strongly modulated in line with the visual search goals of an observer. Here, four electrophysiological studies of attention are presented which focus on yielding insight into how the visual system deals with irrelevant information during visual search and seeks to further our understanding of the PD component. Chapter 2 tests the stimulus conditions necessary to elicit the distractor suppression indexed by the PD by examining how differences in the salience of an irrelevant stimuli affect visual search. Chapter 3 explores how individual differences in target and distractor processing are associated with variations in visual working memory (vWM) capacity. Chapter 4 asks how distractor processing is altered during a disruption of attentional control by examining how visual search is affected during the attentional blink (AB). Chapter 5 explores how high levels of trait anxiety alter inhibitory control and the ability to ignore distracting information. In the final chapter, future directions are discussed and a model for attentional processing is proposed.

Document type: 
Thesis
File(s): 
Senior supervisor: 
John McDonald
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Dissertation) Ph.D.

Multi-GPU accelerated real-time retinal image segmentation

Author: 
Date created: 
2016-11-10
Abstract: 

In recent years, Optical Coherence Tomography (OCT) has become one of the dominant imaging technologies for ophthalmic diagnostics and vision research. The fast and high-resolution cross-sectional data that OCT provides has brought a new possibility in the role of intra-operative imaging. However, existing commercial OCT systems lack the automated real-time functionality for providing immediate feedback of changes in anatomical configuration as the result of surgical actions. The predominant reason for lacking such functionality is because high complexity algorithms are hard to implement in real-time imaging due to their computationally expensive nature. In this thesis, we will present a Graphics Processing Unit (GPU) accelerated retinal layer segmentation for real-time intra-operative imaging applications. Modern GPUs has emerged as a strong tool for mass computation in scientific researches. The computational power of the GPU outpaces Central Processing Unit (CPU) significantly when the processing task is parallelizable. Image segmentation is a computationally expensive algorithm and traditionally implemented in sequential instructions. An example of a parallelizable segmentation algorithm is Push-Relabel (PR) Graph-Cut(GC), which can be implemented using GPU. The GPU Retinal Segmentation (GRS) presented in this thesis is built upon such an algorithm. To ensure the run time of the GRS meets the real-time requirement for its application, multiple GPUs are used to accelerate the segmentation processing further in parallel. As a result of using GRS, we were able to achieve the visualization of the retinal thickness measurement and the enhancement of retinal vasculature networks in real-time.

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

SimBoost: A Read-Across Approach for Drug-Target Interaction Prediction Using Gradient Boosting Machines

Author: 
Date created: 
2016-10-04
Abstract: 

Computational prediction of the interaction between drugs and targets is a standing challenge in drug discovery. High performance on binary drug-target benchmark datasets was reported for a number of methods. A possible drawback of binary data is that missing values and non-interacting drug-target pairs are not differentiated. In this paper, we present a method called SimBoost that predicts the continuous binding affinities of drugs and targets and thus incorporates the whole interaction spectrum from true negative to true positive interactions in the learning phase. Additionally, we propose a version called SimBoostQuant which computes a prediction interval in order to assess the confidence of the predicted affinity. We evaluate SimBoost and SimBoostQuant on three continuous drug-target datasets and show that our methods outperform the state-of-the-art models.

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

Automatic and Non-Invasive Delineation of the Seismocardiogram Signal for the Estimation of Cardiac Time Intervals with Applications in Diastolic Timed Vibration and Early Stage Hemorrhage Detection

Date created: 
2016-10-12
Abstract: 

Seismocardiography is the non-invasive measurement of the heart vibration by placing an accelerometer on the human chest. Due to its non-invasive nature, the seismocardiogram signal could be embedded inside portable devices for the purpose of health monitoring and remote diagnosis. With the combination of the electrocardiogram (ECG) signal, cardiac time intervals (CTI) could be extracted. CTIs are timing intervals that are associated with specific events of the cardiac cycle. The research community has explored the potential of CTI in the diagnosis of chronic myocardial disease, ischemic and coronary artery disease, arterial hypertension, cardiac resynchronization therapy, and implantable cardioverter de-fibrillator. For the extracted CTIs to be useful in a medical device, the seismocardiogram signal (SCG) has to be automatically delineated. Upon the automatic delineation of CTIs, the timing parameters could be either combined with other physiological signals to create new indices that have unique physiological interpretations or to be used as a complimentary technology. Hence, The present dissertation has three main objectives: (1) automatic SCG delineation algorithm, (2) application of cardiac time intervals (extracted from SCG) for generating aunique index for early stage hemorrhage detection, and (3) complementary technology for optimization of the diastolic timed vibration therapy. For the first objective, the proposed delineation algorithm had the capability to correctly estimate the CTIs while discarding low-quality cardiac cycles, which are the ones thatdon’t have identifiable fiducial points. For the second objective, the combination of the electrocardiogram, seismocardiogram, and photoplethysmogram signals was used to design a hemorrhage progression index, which ultimately was applied for early stage detection. For the last objective, the extracted CTIs were applied to the “diastolic timed vibration”, which is a potential therapy for patients with acute ischemia during the pre-hospitalization phase. A calibration methodology was proposed for diastole detection in real-time.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Dr. Carlo Menon
Department: 
Applied Sciences: School of Engineering Science
Thesis type: 
(Thesis) Ph.D.

Continuous Conditional Random Fields for Drug Target Interaction Prediction

Author: 
Date created: 
2016-10-03
Abstract: 

Knowledge about the interaction between drugs and proteins is essential in the drug discovery process. Understanding the relationship between compounds and proteins through wetlab experiments alone is time-consuming and costly. To support the experimental work by prioritizing the most potent compounds for a target, numerous methods for the in-silico prediction of drug-target interaction have been proposed and high performance on binary datasets have been reported. A drawback of binary datasets is that missing values and non-interacting drug-target pairs are not differentiated. In this thesis, a model is developed that predicts the drug-target binding strengths as continuous values and thus incorporates the whole interaction spectrum from true negative to true positive interaction. The developed model combines two previously used approaches for the problem, which are Matrix Factorization and Conditional Random Fields. The model is evaluated on three datasets and a slight performance improvement is observed when compared to the state of the art method.

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

Skwxwú7mesh Nách’en: Xwech’shí7 tlʼa Nexwníneẁ iy Sneẁíyelh Squamish Praxis the interspace of Upbringing and the Teachings

Date created: 
2016-11-30
Abstract: 

In Canada, First Nations languages are in a grave state of decline. Skwxwú7mesh (Squamish) is a critically endangered language. In Circle, a form of knowledge gathering that has been adapted for this research, co-participants take up the two notions of nexwnínew̉ and snew̉íyelh (upbringing and the teachings). The premise in the research is that Skwxwú7mesh people are engaged in a socialization process, which has at the crux an intergenerational pedagogy of Skwxwú7mesh language, culture, and knowledge re-generation enculturated through family relations in formal and informal ways manifest in their nexwnínew̉ and snew̉íyelh. Based upon the cultural practice Utsám̉ Chiỷáxw (Called to Witness) protocol co-participants become the Witnesses called to “put words to the floor”. This study uses an emergent Skwxwú7mesh theory called Nch’u7mút (united as one) that privileges the Swa7ám̉ (Ancestors) epistemological and ontological knowledge systems. Four principles wanáxw̉s (respect), smenálhwit (dignity), áyatway (kindness), and chénchenstwaywit (support for one another) shape the theory. Xay Sts’its’áp’ (Sacred Work) is a Skwxwú7mesh chiỷáxw (protocol) that frames this dissertation. I use the term Work italicized and capitalized to symbolize respect for the ceremony of research. The findings offer the reader, the co-participant’s critical insights into the Skwxwú7mesh moral universe and the connection of language to land.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Carolyn Mamchur
Graham Smith
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) Ed.D.

A "Minor League Equivalent to the Eiffel Tower and the Empire State Building": Vancouver's Penthouse Nightclub

Author: 
Date created: 
2016-12-14
Abstract: 

The Penthouse is rumoured to be the oldest continuously operating nightclub in the land we now know as Canada and is without a doubt the oldest exotic nightclub. Owned and operated by an Italian family who emigrated to Vancouver, British Columbia, The Penthouse has survived numerous waves of moral crackdown in the city as well as many offers to buy the prime location in the face of aggressive development. A staggering number of nightclubs in Vancouver, exotic or otherwise, have not shared the same fate. Through conducting an institutional history of The Penthouse I locate it within changing local politics related to feminist activism, policing, and the sex industry as well as larger shifts in cultural attitudes towards sexual labour and sex workers’ bodies. Further I assemble a social history of the dancers, looking at their experiences in the club and their perception of the intersections between feminism, identity, performance, and sex. Feminist theory, women’s and gender history, and performance studies inform this multi-method project, which includes results and analysis from archival research and oral history interviews conducted with dancers employed at the club from 1978-2012. Overwhelmingly, the narrators reflected on their time as dancers as valuable to their lives in a myriad of ways, including helping to foster healthy relationships with their bodies and sexualities. Nevertheless most felt that the stigma they faced as sexual labourers impacted their lives in a negative way and was in conflict with the way they experienced their work themselves. This ongoing stigma was often a driving force for abandoning striptease for more ‘square’ or respectable work. Others continue to work in the sex industry. Eleven dancers shared their stories for this project, as did one member of the serving staff at The Penthouse, booking agent Randy Knowlan, and current owner/operator Danny Filippone. These stories offer a history of the Penthouse which places it as a central part of Vancouver’s history. At a time when conventional striptease seems to be in decline and other facets of the sex industry seem to be under attack by new forms of criminal regulation, the interviews with dancers, staff, and the owner/operator suggest that future possibilities for Vancouver’s contemporary striptease communities might lie in the evolving local neo-burlesque scene.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Lara Campbell
Department: 
Arts & Social Sciences: Department of Gender, Sexuality, and Women's Studies
Thesis type: 
(Thesis) Ph.D.

A Spatial Analysis of Pleistocene-Holocene Transition Sites in the Southern Columbia Plateau and Northern Great Basin of North America

Date created: 
2016-08-10
Abstract: 

The Western Pluvial Lakes Tradition was proposed by Stephen Bedwell in 1973 to account for an early Holocene lake-marsh-grassland environment adaptation for hunter-gatherers living in the southern Columbia Plateau and western Great Basin of North America. Since then, archaeological site research and regional syntheses have supported this hypothesis with information on concentrations of early archaeological sites found on ancient wetland margins. However, Plateau-Basin archaeology tends to focus on site- and basin-specific analyses to support early subsistence-settlement hypotheses. To explore whether pluvial lakes were central to regional resource use and mobility patterns at the Pleistocene-Holocene transition, it is necessary to broaden the scale of analysis from typical basin-focused studies. Paleoenvironmental and archaeological spatial data from the Burns and Vale Oregon Bureau of Land Management districts are used in this thesis to explore the centrality of pluvial lakes for early peoples across the dynamic landscape of the Plateau-Basin region at the Pleistocene-Holocene transition. This research utilizes data collected in a cultural resource management environment to study spatial bias in data collection and analysis, as well as explore the potential benefits of using under-utilized isolate data collected in a cultural resource management research environment. The statistical analyses in this study confirm a regional association between early Holocene archaeological sites and pluvial lakes, but also indicate that the early Holocene economy was more diverse than is typically suggested in Western Pluvial Lakes Tradition research.

Document type: 
Thesis
File(s): 
Senior supervisor: 
George Nicholas
Department: 
Environment: Department of Archaeology
Thesis type: 
(Thesis) M.A.