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.

The effect of mowing and hand removal on the regrowth rate of Himalayan blackberry (Rubus armeniacus)

Author: 
Date created: 
2018-04-19
Abstract: 

Himalayan blackberry (Rubus armeniacus Focke) is an invasive species in the Pacific Northwest. Mowing and hand removal are two of the common treatments used for controlling Himalayan blackberry. I examined the effectiveness of mowing, hand removal, and control treatments by measuring the mean number of stem and mean stem length during a growing season. Treatments were applied on March 2017. Bi-weekly sampling was from April to August 2017. Data were analyzed with a two-factor split-plot Analysis of Variance (ANOVA) test. The overall trend showed no statistically significant difference between mowing and hand removal treatments in one growing season. Integrated treatments (e.g. mowing + hand removal + planting) are recommended to be used to effectively reduce Himalayan blackberry cover because one removal treatment showed to be insufficient to eliminate Himalayan blackberry.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Scott Harrison
Department: 
Environment:
Thesis type: 
(Project) M.Sc.

An in-depth study on Power Line Communications

Author: 
Date created: 
2018-04-13
Abstract: 

Power Line Communication has acquired tremendous interest from the research community since its applications and development in the field of Smart grid, in-home & vehicular communication, and its role in Internet of Things (IoT). In this project, I study the features of power line communication and provide an overview of applications in both narrowband and broadband systems, listing applicable standards and specifications. We study the problems in the technology and how recent developments have led to resolve them. A number of tests were conducted for the in-home Power Line Communication (PLC) setup, and different PLC modules were tested for a variety of wiring systems. Further, we conducted tests on two transformers to list the frequencies that can pass through the system, and to study general behaviour of the system to high frequencies.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Ash M. Parameswaran
Department: 
Applied Sciences: School of Engineering Science
Thesis type: 
(Project) M.Eng.

The impact of early adversity on mental health in young adulthood: Findings from the Romanian Adoption Project

Author: 
Date created: 
2018-04-26
Abstract: 

This longitudinal study is a part of the fifth phase of the Romanian Adoption Project and explored the impact of early adversity on mental health and behaviour problems in adolescence and early adulthood in a group of Romanian adoptees (N= 47; 22 males; mean age at assessment= 26.77) who were adopted to Canada in 1990/91 and have been followed in this project since early childhood. Behaviour problems in adulthood were assessed with parent reports on the Adult Behaviour Checklists (ABCL, Achenbach, 1997). In adolescence behaviour problems were assessed with the parent report form of the Child Behaviour Checklist (Achenbach, 1991). Mental health problems both in adolescence and adulthood were assessed using parents’ responses to 12 questions asking if adoptees had received any of a list of mental health diagnosis. The effect of duration of deprivation was examined by dividing adoptees into two groups based on time they spent in adversity pre-adoption; those who spent less than 4 months in adversity, and those who spent more than 8 months in adversity. Statistical analyses showed that in adolescence 34% of the sample had at least one mental health diagnosis and this number increased to 50% in adulthood. Levels of behaviour problems were relatively stable from adolescence to adulthood. Females had higher levels of Internalizing behaviour problems than males in adulthood, but no other gender differences were found. Adolescents with more behaviour problems were more likely to have a mental health diagnosis in young adulthood. Also, adoptees with more than one diagnosis in adulthood had more behaviour problems both concurrently and in adolescence than adoptees with one or no mental health diagnoses. Longer experience of early adversity prior adoption was not associated with either more mental health diagnoses or more behaviour problems at either 16.5 or 26.5 years of age.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Lucy Le Mare
Department: 
Education: Faculty of Education
Thesis type: 
(Thesis) M.A.

Characterization of present biological conditions in the intertidal community across Howe Sound, British Columbia

Date created: 
2018-04-25
Abstract: 

Howe Sound is a Pacific Northwest fjord located north of Vancouver, British Columbia. This fjord has been impacted by effluents from several industries including two pulp mills and a copper mine. After Environment Canada undertook more stringent enforcement on environmental standards in the 1980s, the Britannia copper mine and the Woodfibre pulp and paper mill were shut down. Historical data from the intertidal community indicate that recovery of the ecosystems in these areas has been minimal, particularly at sites in close proximity to industrial activities. The goal of this study was to begin a characterization of several present biological conditions in the intertidal community across Howe Sound. Six sites were selected and grouped based on degree of exposure to industrial activities. High exposure sites included Britannia Beach, Darrell Bay and Port Mellon, while moderate exposure sites included Porteau Cove and Lions Bay. Chaster bay was selected as a reference site for this study. Two biomarkers of exposure; ethoxyresorufin-O-deethylase (EROD) and metallothionein (MT) were measured in mussels to assess the availability of polyaromatic hydrocarbons and metals at these sites. When compared to the Chaster Bay reference site, EROD activity was significantly higher in mussels collected from the two high exposure sites (Britannia Beach (~2.1 increase) and Port Mellon (~1.5 increase)) and the two moderate exposure sites (Porteau Cove (~1.8 increase) and Lions Bay (~1.6 increase). MT levels were significantly higher in mussels from the Britannia Beach (~4.2 increase), Darrell Bay (~2.8 increase) and Porteau Cove (~2.4 increase). Results from another ecological bioindicator (giant kelp) showed that germination rates were significantly lower at Lions Bay, Port Mellon and Darrel Bay (> 60% reduction compared to the reference site). A 16% reduction in germination rate was also noted for Britannia Beach. Germination tube length were only found to be significantly reduced at Lions Bay (~20 % decrease), Darrell Bay (~37% decrease) and Britannia Beach (~10% decrease). Finally, in an intertidal community assessment using species richness as an index, Chaster Bay contributed 39.94% to the total species richness, a range of 17.78% - 19.02% for moderate exposure sites and 4.50% - 12.79% for the high exposure sites.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Chris Kennedy
Department: 
Science: Biological Sciences Department
Thesis type: 
(Project) M.E.T.

An improved synthesis of gold nanorods with tunable dimensions and localized surface plasmon resonance properties

Author: 
Date created: 
2018-04-19
Abstract: 

Gold nanorods have been pursued due to their unique optoelectronic properties, which have led to potential uses in multiple applications. We sought to prepare gold nanorods that would potentially be used in biomedical applications, such as bio-imaging, photothermal therapies, and drug delivery systems. Typically in biomedical applications, gold nanorods with a localized surface plasmon resonance band that lies in the near infrared window between 650 to 1350 nm is highly desirable to obtain better images and an efficient photothermal effect over a range of depths within biological tissues. In addition, the dimensions of gold nanorods also play an important role in terms of cellular uptake and retention, as well as controlling the ratio between their absorbance and scattering properties. Thus, a primary goal of our study was to regulate dimensions and localized surface plasmon resonance of the gold nanorods to improve their potential utility in applications requiring both cellular uptake and photothermal triggered processes through the use of localized surface plasmon resonance bands in the near infrared “window”. We have modified the seed-mediated method by sequentially varying concentrations of hydrochloric acid and chloroauric acid to tune the dimensions, and thus the properties of the gold nanorods. The average dimensions of the gold nanorods were tuned from 24±4 nm in length and 7±1 nm in width, to 47±10 nm in length and 11±2 nm in width from these adjustments in the concentration of hydrochloric acid and chloroauric acid in the growth solution.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Byron D. Gates
Department: 
Science: Department of Chemistry
Thesis type: 
(Thesis) M.Sc.

Developing effective and culturally appropriate speech-language services for First Nations children living on-reserve

Date created: 
2018-03-19
Abstract: 

Research conducted by the First Nations Information Governance Centre and Aboriginal Child Survey have found speech and language delays to be the most common developmental challenge facing First Nations children. Despite the prevalence of these challenges, many First Nations children in B.C. are unable to receive adequate speech and language services due to barriers such as geographic location, service coordination, and the lack of culturally appropriate services. This capstone employs a literature, jurisdictional scan, and expert interviews investigate these barriers and to propose three policy options to address them. The proposed options are then evaluated using a multi-criteria analysis. Through this analysis, this capstone makes a series of short and long-term recommendations to promote language development and improve the ability of First Nations children in B.C. to access culturally appropriate speech-language services.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Olena Hankivsky
Department: 
Arts & Social Sciences: School of Public Policy
Thesis type: 
(Project) M.P.P.

Use of digital records for studying skill learning

Date created: 
2018-04-27
Abstract: 

The present work uses a novel data source, real-time strategy video game play in StarCraft 2, to study complex skill learning. Chapter One discusses some important desiderata of a large dataset. Chapter Two discusses domain specifics about StarCraft 2, and introduces the process by which survey respondents donate digital archives which are parsed to reveal second-by-second information about in-game performance of players. Chapter Three asks how experience should be defined in a complex domain. I find that the common-sense definition, that experience should be measured soley in terms ot task-specific experience, misleads researchers by being both overly permissive and restrictive. A better definition can be achieved by focusing on other forms of experience, such as experience with different game modes. Chapter Four extends a previous study of age-related declines in a StarCraft 2 cross-sectional dataset. Segmented regression models are used to estimate the onset of age-related differences. Secondly, I examine the theory that large swaths of age-related differences, across a wide array of variables, are attributable to a single general cognitive, but not psychomotor, factor. I find support for this theory, as a simplified measure of redundant click-speed accounts for about 19\% of the shared age-related variance in established measures of StarCraft 2 speed. In Chapter Five I examine some of the common responses to the idea that Big Data, and the emerging data sources they employ, could effectively replace the role of theory in science. I argue, instead, that emerging data sources are a threat to overzealous generalizations from laboratory grown theories to complex behaviour. If emerging data sources fulfill their potential as tools for evaluating theory generality, then scientific standards for making claims about generality could change in pronounced ways. This would create a bigger gap between empirically grounded generalizations from the laboratory to life and careless generalizations which Frankfurt would call ``bullshit.'' Finally, I examine two very different research strategies for going about the evaluation of theory using Big Data, and point to the virtues and limitations of both.

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

Effects of farming practices and landscape composition on wild invertebrate pollinator and bird abundance, richness and health

Date created: 
2018-04-11
Abstract: 

Wildlife biodiversity is threatened by agricultural intensification, which reduces and fragments natural habitat. I examine how farming practices and landscape composition influence wild pollinators and birds that inhabit these ecosystems. I also assess pollen foraging preferences of wild bumble bees and the effect of foraging preferences on their health. Forest cover was the main predictor of wild pollinator and bird abundance and richness, and floral resource availability also increased the abundance and richness of pollinators. There was no effect of farm management type (organic vs. conventional) on abundance or diversity of either pollinators or birds. Bumble bees showed a strong foraging preference for flowers not found on farms, and those collected in natural areas had higher body fat content than bees collected on farms. These results emphasize the importance of the conservation of natural habitat adjacent to agricultural areas for biodiversity, and of floral resources in natural areas for pollinator health.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Elizabeth Elle
Department: 
Science: Biological Sciences Department
Thesis type: 
(Thesis) M.Sc.

Novel nonlinear sliding mode observers for state and parameter estimation

Author: 
Date created: 
2018-04-16
Abstract: 

Interest in the area of state and parameter estimation in nonlinear systems has grown significantly in recent years. The use of sliding mode observers promises superior robustness characteristics that make them very attractive for noisy uncertain systems. In this thesis, a novel Time-Averaged Lypunov functional (TAL) is proposed that examines the effect of Gaussian noise on the stability of a sliding mode observer. The TAL averages the Lyapunov analysis over a small finite time interval, allowing for intuitive analysis of noises and disturbances affecting the system. Initially, a sliding mode observer for a linear system is analysed using the proposed functional. Later, the results are extended to various classes of nonlinear systems. The necessary and sufficient conditions for the existence of the observer are presented in the form of Linear Matrix Inequality (LMI), which can be explicitly solved offline using commercial LMI solvers. The types of nonlinearity examined are fairly general and embodies Lipschitz, bounded Jacobian, Sector bounded and Dissipative nonlinearities. All the system models considered are highly nonlinear and consist of system disturbances and sensor noise. The proposed sliding mode observer provides less conservative conditions to verify the existence and stability of the observer. The observer can also be effectively used for unknown parameter estimation as outlined in the final chapter of this report. Various examples are provided throughout the premise to support the proposed observer design and demonstrate its effectiveness.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Krishna Vijayaraghavan
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Exploring behavioral data in online social media with focus on user connectivity and mobility

Author: 
Date created: 
2018-04-23
Abstract: 

With the booming development of online social media in recent years, massive and variety of behavioral data, such as social interactions data and user's E-travel sharing data, are generated by the users throughout the world everyday. Exploring and analyzing such data helps to understand users' preferences, unearth the contained tremendous knowledge, and identify new problems and business opportunities, thus is beneficial for social media users, service providers, etc. In this thesis, we are specifically interested in the user connectivity/interaction behaviors, e.g., friendship creation, and the mobility behaviors, e.g., check-in sequence at Point-of-Interest (POIs), that involve rich semantic information on nodes and edges of the social networks, and study three practical problems in different applications. We first analyze users' social connectivity behaviors from a new angle and study a problem of mining non-homophily social ties, aiming at discovering interesting but unexpected group-level social ties that do not follow the homophily phenomenon. We propose a novel ranking metric to identify such social ties and develop an efficient mining algorithm specifically for the new metric. In our second work, we explore users' check-in sequences or travel routes, and study a problem of personalized trip recommendation meets real-world constraints, by considering personalized rating on POIs and multiple constraints such as the time budget, the time window for the POI availability, the uncertainty of traveling time between POIs. We develop two efficient optimal solutions and two heuristic solutions for finding "good trips" with a significantly better runtime. Finally, in consideration of the sparsity of users' historical rating data and people's dynamically changed mind over time, we further study an on-demand route search problem with personalized diversity requirement on POIs, where users can specify their preferred features for the route and a personalized quantity (number of POIs) and variety (the coverage of the specified features) trade-offs. We propose to model users' personalized route diversity requirement by submodular functions that support the diminishing marginal utility property. We design generic and elegant optimal algorithm as well as heuristic algorithms. Comprehensive empirical evaluations on real life data sets demonstrate the effectiveness and efficiency of our methods.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ke Wang
Department: 
Applied Sciences: School of Computing Science
Thesis type: 
(Thesis) Ph.D.