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.

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.

Development of a motion vector field model of an unstable slope using terrestrial radar interferometry

Date created: 
2018-04-20
Abstract: 

200 kilometres southeast by south of Fairbanks, Alaska lies the Fels Glacier valley where within, several sections of the northern slope are experiencing active deep-seated gravitational slope deformation. High-temporal resolution terrestrial radar imagery of the westernmost such section was acquired over the course of a 3-day field campaign in July 2017. These data were analyzed using interferometric techniques with the goal of extracting the rate of deformation across the 3-kilometre-wide section. The analysis and resulting motion vector field model reveal the extent and relative magnitude of the most actively deforming region located at the base of the slope with respect to the main body of the slope as observed over the short duration of the campaign.

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

Three reincarnations of the Smilin' Buddha Cabaret: Entertainment, gentrification, and respectability in Vancouver's Downtown Eastside 1952-84

Author: 
Date created: 
2018-02-23
Abstract: 

The Smilin' Buddha Cabaret operated at 109 East Hastings Street in Vancouver's Downtown Eastside (DTES) neighbourhood from 1952 until the late 1980s. Over its forty year history, this club hosted variety shows, striptease dancers, and musicians from the city's jazz, rhythm and blues, and punk rock music scenes. Today, the building that was home to the Smilin' Buddha sits in the middle of a neighbourhood undergoing a contested transformation as new upscale develops redefine the historically low-income, working-class neighbourhood. At the same time, the club is being creatively reinterpreted as a symbol of the city's postwar prosperity and rich entertainment history where it was once described primarily as a skid row dive bar. This thesis traces the changes through the history of the Smilin' Buddha to understand how the club and its entertainment evolved in relation and in opposition to the development of the neighbourhood's built environment, geography, and identity. Through this, I argue that the development of the Smilin' Buddha and the wider DTES has never been the result of natural market forces; instead, it has always been a site of negotiation and contestation among multiple overlapping interests who do not have equal access to power. At the same time, it has been a site of cultural vitality, even if it has not been a site of economic vitality.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Nicolas Kenny
Elise Chenier
Department: 
Arts & Social Sciences: Department of History
Thesis type: 
(Thesis) M.A.

The critical construction of geolocational life

Author: 
Date created: 
2018-04-24
Abstract: 

This dissertation is an analysis of the widespread adoption of locative digital media in urban space. Building upon prior phenomenological theories of mobile interfaces and critical theories of technology, I provide an account of the micropolitics of locative media, using locational literacy as a key concept for articulating a renewed, and politically and ethically empowered understanding of how locative media play important roles in modern urban experiences. The thesis proceeds by first contextualizing the idea of locational literacy within locative media studies and mobilities research. I then elaborate the idea of locational literacy by synthesizing phenomenological and critical theories of technology, including Andrew Feenberg's critical constructivist approach (2002) in order to problematize geolocational media as a site of micropolitical struggle. Then I provide an account and analysis of field data collected through my ethnographic research. Here, I show how geolocational media users come to terms with and organize their values, attitudes, and identities through media technologies, and how both individual technical knowledge and institutional constraints influence their relative access to and effective use of geolocational media. Further on, I describe a user experience study involving mobile phone users, who were surveyed (a) before and (b) after using a geolocation tracking app for a two week period. In this discussion, I show how geolocational awareness is associated with attitudes, values, and opinions about urban life, sustainability and mobile locative devices. I conclude the dissertation with the claim that the potential for perceptual shifting enabled by geolocational media empowers individuals – albeit somewhat unevenly – in very particular ways. This perceptual shift and sense of empowerment, I argue, can lead to improved forms of community interaction and deliberation, which hinges on an express articulation and acknowledgement of locational media literacy in everyday experience. I also examine how the micropolitical struggles of users with geolocational media signify the potential for broader political change as these technologies become progressively more accurate and granular, and more surveillant and invasive.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Richard Smith
Department: 
Communication, Art & Technology: School of Communication
Thesis type: 
(Thesis) Ph.D.

#Unions: Canadian unions and social media

Date created: 
2018-04-19
Abstract: 

By changing the connectivity between people across the globe, the rise of social media has shifted the resources and capacities of political activists, opening up new horizons for social movements. Many of the labour movement’s renewal goals—such as improving equity within unions, adopting more inclusive grassroots organizing, and reaching out to a precarious, fragmented workforce—seem to line up with this open potential of social media. However, existing research on unions’ use of social media suggests the goals and practice don’t align, arguing that unions tend to use social media in a unidirectional, centralized way. To explore this discord, this study investigates the use of social media by four of Canada’s largest labour organizations—the Canadian Union of Public Employees (CUPE), the United Food and Commercial Workers Canada (UFCW), Unifor Canada, and the Canadian Labour Congress (CLC). In comparing the strategies expressed in interviews with key communications staff and the practices evident in the unions’ social media output with the stated principles and goals of the organizations as a whole, a number of tensions between labour communications and social media platforms become evident. On the one hand, unions struggle in maintaining centrally controlled messaging in a context that favours open, pluralistic communications. On the other hand, while social media has become an essential arena for public discourse, it’s one where the connectivity it offers is manipulated by algorithms created in the interest of private profit. There is a clear and compelling need to strengthen Canadian unions in order to address growing economic inequality, and by filling gaps in the research of unions’ current communication strategies, this study can contribute to efforts to formulate some best practices for using social media as a democratic tool in the Canadian labour movement.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Enda Brophy
Department: 
Communication, Art & Technology: School of Communication
Thesis type: 
(Thesis) M.A.

The importance of a well-designed digital magazine

Date created: 
2018-04-19
Abstract: 

We now live in an era where magazines are more than a print entity: they are brands that are supported by a wide array of platforms. Websites are amongst the most common platforms as they are easy to create and they help magazines reach a wider audience, which often results in an increase in advertising sales. These websites, however, are in constant competition for readers’ attention. For that reason, it is important for a magazine’s website to offer a high-quality branded user-experience to their current and future readers. This report explores the Western Living’s brand and analyses their website based on user experience (UX) and user interface (UI) principles. It then gives some suggestions that would ultimately improve the overall usability of the site.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Mauve Page
Department: 
Communication, Art & Technology: Publishing Program
Thesis type: 
(Project) M.Pub.

Enabling autonomous mobile robots in dynamic environments with computer vision

Date created: 
2018-04-19
Abstract: 

Autonomous mobile robots are becoming more prevalent in our society as they become more useful. Often the environments we would like to see robots working in will be dynamic, with objects like people moving throughout. This thesis explores methods to make autonomous mobile robots more effective in the presence of dynamic objects. Specifically, two applications are developed on top of existing computer vision techniques where robots interact directly with moving objects. The first application involves multiple robots collaboratively sensing and following an arbitrary moving object. This is the first demonstration of its kind where robots jointly localize themselves and an object of interest while planning motion that is sympathetic to the vision system. Live robot experiments are conducted demonstrating the efficacy of the proposed system. The second application is a novel human-robot interaction system based on face engagement applied to an unmanned aerial vehicle (UAV). A unique use of facial recognition software enables an uninstrumented user to command a UAV with only their face. A series of experiments demonstrate the effectiveness of the interaction system for sending UAVs on a variety of flight trajectories.

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

Numerical modeling of highly saline wastewater disposal in Northeast British Columbia

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

Dense, saline wastewater generated during oil and gas activities (hydraulic fracturing and production) is commonly disposed of in deep formations, but the migration of this wastewater after entering the subsurface is poorly understood. This study uses numerical models to simulate wastewater disposal in the Paddy-Cadotte of Northeast British Columbia using both single-well axisymmetric box models and a regional model of the formation in which multiple disposal and water source wells operate. A sensitivity analysis performed on the box models reveals that dispersivity and permeability exert the strongest control on overall wastewater distribution. Models show that wastewater migrates further than predicted using a simple volumetric calculation, and extends further along the base of the formation than the top due to variations in fluid density. Interference between disposal and source wells is observed to influence wastewater migration, while formation dip and regional groundwater flow have no discernible impact.

Document type: 
Thesis
Senior supervisor: 
Diana Allen
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

The social life of monitoring and evaluation: An ethnography of the monitoring and evaluation of an HIV/AIDS prevention program in Ghana

Date created: 
2018-03-14
Abstract: 

Globally, HIV/AIDS programs face pressure to document accountability and achievement via “evidence-based” criteria or “monitoring and evaluation” (“M&E”). Donors have increasingly made M&E a funding stipulation funding. They want numeric data that speak to universal indicators of efficacy, a newly hegemonic means of assessment in the field of governance based in business management. Advanced by major global institutions like the United States President’s Emergency Plan for AID Relief (PEPFAR), M&E systems—structures of metrics, procedures, people, and technology—are variously set up around the globe. M&E plays an increasingly deeper role through a program’s entire lifespan and in the daily activities of program workers. Yet surprisingly, little is known about how M&E occurs on the ground and the social and political effects: What kinds of actions and social relations does M&E instigate? How does its practice maintain or challenge the status quo? Furthermore, “developing” countries, incredibly dependent on foreign program funding, encounter M&E through uneven postcolonial relations. How does M&E reflect and possibly influence postcolonial relationships, and country sovereignty? My dissertation explores these questions through an ethnographic study of the M&E of an HIV/AIDS prevention program in Ghana called BRIDGES, funded by the United States Agency for International Development (USAID). For 20 months I followed the M&E of BRIDGES through a focus on one non-governmental organization (NGO). I argue that M&E is a key site through which HIV/AIDS intervention is trans/formed. It not only reflects but also produces (unexpected) social relations and habits, which shape how HIV/AIDS intervention operates. In Ghana, M&E unintentionally deepened unequal relations between donor-recipient, organizations, and personnel. I demonstrate that this effect occurred on and through the practices and agency of those governed by M&E. M&E is not an agent in its own right, but is deployed in particular ways by actors in fields of power.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Stacy Leigh Pigg
Department: 
Arts & Social Sciences: Department of Sociology and Anthropology
Thesis type: 
(Thesis) Ph.D.