Graduate & Postdoctoral Studies

Permanent URI for this communityhttps://hdl.handle.net/10155/4

The faculty of Graduate & Postdoctoral Studies offers a number of services to graduate students to help them hone their professional skills and development during their tenure at Ontario Tech. They have facilitated the 3 Minute Thesis competition since 2013. The competition is a university-wide competition for graduate students in which participants present their research and its wider impact in three minutes or less to a panel of non-specialist judges.

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Now showing 1 - 20 of 1652

404 not found error: searching for truth in privatized corrections through online material
(2012-12-01) Gould, Lakelan Richard; Perry, Barbara; Avi, Shahid
In the last three decades private involvement in correctional service has transformed. Since the 1980s private interest in correctional service has evolved from the delivery of tertiary and secondary services such as transportation, food, and medical services toward the provision of primary services such as design, construction, and complete management of correctional facilities. In an attempt to fill a gap in the literature surrounding correctional privatization, I examine to what extent corporate published online material explores the issue of incarceration, underlying theoretical ideology of prison, and what general and specific information is presented to online readers. Using a content analysis, results indicate inaccurate and incomplete information is presented to online readers culminating with incarceration constructed as the only choice to combat crime. Results also indicate strong Neo-liberal doctrine underlining the material, specifically, strong support for continued privatization, offender commodification, continued deregulation of public service, belief in the free market, and the transfer of government to corporate control. Together, these themes highlight the extension of a new economy of the power to punish.
A few-shot learning method for single-object visual anomaly detection
(2024-04-01) Ejaz, Neha; Qureshi, Faisal
We propose a few-shot learning method for visually inspecting single objects in an industrial setting. The proposed method is able to identify whether or not an object is defective by comparing its visual appearance with a small set of images of the “working” object, i.e., the object that passes the visual inspection. The method does not require images of defective objects. Furthermore, the method does not need to be “trained” when used to inspect new, previously unseen, objects. This suggests that the method can be easily deployed in industrial settings. We have evaluated the method on three visual anomaly detection benchmarks—1) MVTec, 2) MPDD, and 3) VisA. On the first two datasets the proposed method achieves performance that is comparable to state-ofthe- art methods that require access to object-specific training data. Model performance on VisA is poor; however, it is to be noted that the model was never trained on VisA dataset. We also show that the proposed model boasts fast inference times, which is a plus for industry applications. This project is funded in part by Axiom Plastics Inc., and we have evaluated the proposed method on a proprietary dataset provided by Axiom. The results confirm that the proposed method is well-suited for single-object visual anomaly detection in industry settings.
A Graph Neural Network for pairwise surrogate modeling in population-based algorithms with tournament selection
(2024-04-01) Gharavian, Vida; Makrehchi, Masoud; Rahnamayan, Shahryar
Optimization problems widely arise in various science and engineering fields. Optimisation involves evaluating a candidate solution, which can be computationally intensive. Machine learning-based surrogate models can contribute to learning the specific pattern among the decision variables and objective values to reduce the computation time of fitness evaluation. In this study, we have proposed a novel pairwise surrogate model to identify the superiority between candidate solutions in a pairwise comparison. We demonstrated a Graph Neural Network (GNN) to be trained on number of pairs, then utilized to compare a pair of candidate solutions. To examine the efficacy of our model, we utilized the surrogate model on CEC2017 benchmarks in different dimensions. Moreover, the result of surrogate-assisted and none-assisted form of two well-known optimization algorithms were compared. Results show that the proposed method can significantly reduce the computing cost. In the presence of higher dimensions, our model is more effective than most surrogate models for comparison-based optimizers.
A hybrid approach for intersection management in V2X-enabled connected vehicles
(2024-08-01) Elmoghazy, Ammar; Elgazzar, Khalid; AlWidian, Sanaa
Autonomous Vehicles (AVs) have the potential to revolutionize transportation by enhancing safety, efficiency, and convenience. However, AVs face significant challenges in complex urban environments, particularly in accurately perceiving and navigating through intersections mainly due to occlusions. This thesis addresses these challenges by integrating Vehicle-to-Everything (V2X) communication with onboard sensors to improve AV perception and decision-making capabilities. In particular, this thesis proposes a hybrid centralized-decentralized management system, which maximizes the benefits of centralized control for strategic traffic management and the responsiveness of decentralized decision-making, using edge nodes as a traffic coordinators helps reduces the computational needs on the vehicle. Such a system leverages V2X data to enhance situational awareness, optimize traffic flow, and improve overall safety and efficiency in urban environments. The methodology involves using Simultaneous Localisation and Mapping - SLAM for mapping, particle filters for localization, and waypoint generation for planning and control. The hybrid system’s performance was evaluated through simulations and real-world experiments using scaled-down vehicles equipped with advanced sensing and communication technologies. Compared to purely centralized or decentralized approaches, the hybrid system achieved up to a 14% reduction in average travel times through intersections and a 20% improvement in overall traffic flow efficiency. This thesis contributes to the development of intelligent transportation systems by demonstrating the efficacy of hybrid intersection management in enhancing AV performance in urban environments.
A hybrid compensation-based misalignment tolerant wireless power transfer system for e-mobility
(2024-04-01) Shrestha, Niranjan; Williamson, Sheldon
The thesis focuses on developing a hybrid compensation with a phase shift control strategy, aiming for misalignment tolerant constant current/constant voltage (CC/CV) charging through a wireless power transfer (WPT) system for e-mobility. The thesis proposes a hybrid multi-resonant compensation network (LCC-LCC and LCC-S) for CC/CV charging during perfect alignment, controlled by the secondary side only. Additionally, the thesis introduces a phase shift control technique in the inverter to maintain the corresponding CC and CV charging mode during the misalignment up to 100 mm between primary and secondary coils. Initially, the theoretical analysis of the proposed system is described in detail. Then, simulation results for 3.7 kW and 270 W peak load were carried out in MATLAB Simulink. Lastly, experimental testing and validation were conducted for the proposed hybrid compensated system for 270 W peak load, applicable to the E-bike. The experimental results show good consistency with theoretical and simulation analysis.
A multistage-constant-current, temperature-controlled, health-conscious fast charging algorithm for lithium-ion batteries
(2024-08-01) Chetri, Chandan; Williamson, Sheldon
The economical operation and wider adaptability of an electric vehicle (EV) is highly governed by the energy storage system used in the vehicle. To enhance user convenience and compete with their gasoline counterparts, EVs need fast charging methods to achieve equivalent refueling times. However, fast charging can adversely affect the health and cycle life of the battery due to excessive temperature rise resulting in accelerated degradation of the battery chemistry. Especially in subzero conditions, the chemical reactions are much slower, resulting in increased internal impedance. This leads to a higher rate of temperature rise in battery temperature and eventually faster battery degradation. This thesis proposes a closed-loop Multistage-constant-current, Temperature-controlled (MCC-TC), Health-conscious Fast Charging strategy, which modulates the charging current considering the battery temperature as feedback. The experimental validation on an automotive grade battery cell depicts lower temperature rise and rate of temperature rise following the MCC-TC charging algorithm compared to the conventional Constant-Current Constant-Voltage (CC-CV) charging algorithm.
A novel approach for route generation and real-time scheduling for public services
(2024-04-01) Baghyari, Farhad; Seo, Jaho
Snowplowing and sweeping are essential services to municipalities, which affect travel safety, environment protection, and health to residents. To provide acceptable quality services, route optimization is one of the key strategies that allow for enhancing efficiency, saving costs, and balancing workloads among operational teams. In order to address this issue and reflect on recent research trends in routing problems that require variable conditions and real-time events, this study proposes two heuristic methods: Smart Selective Navigator and a two-stage algorithm for real-time scheduling and route generation. Through two major case studies — winter operations in the City of Oshawa and autonomous street sweeping in Uchi Park —the proposed methods demonstrate superior performance in generating optimal routes that satisfy complex constraints such as turn restrictions and supply limits and handle real-time events like vehicle breakdowns.
A study of meta-learning methods on the problem of video matting
(2024-04-01) Tabaraki, Negin; Qureshi, Faisal; Pu, Ken
Applying image matting techniques directly to video matting presents challenges, primarily due to the complex temporal dynamics inherent in video data. In this work, we studied two Meta Learning approaches—Boosting with Adapters (BwA) and Boosting using Ensemble (BuE)—to tackle the task of video matting using pre-trained image matting models. BwA refines (image matting) alpha mattes by fine tuning pre-trained segmentation models, which we refer to as adapters, using video frames. BuE, additionally, combines multiple fine-tuned adapters using a convolutional neural network. We introduced a meta-learning architecture that incorporates both adapters and ensemble boosting through an iterative process of expert selection and fine tuning. Based on our evaluation on benchmarks based on a standard video matting dataset (VideoMatte240K), we confirm that the proposed scheme improves the performance of image matting models on the task of video matting. In addition, the proposed approach also improves the performance of VMFormer (c. 2022), a recent video matting method.
A targeted reverse mapping machine learning approach for non-dominated solutions in multi-objective optimization
(2024-08-01) Kermani Poor, Masoud; Ibrahimi, Mehran; Rahnamayan, Shahryar
Multi-objective optimization problems aim to identify solutions that maximize or minimize conflicting objectives. Population-based multi-objective algorithms, inspired by biological populations, are effective but often provide limited solutions within the decisionmakers’ region of interest (ROI) on the Pareto front. Recent advancements in machine learning have shown promise in generating solutions, yet they suffer from a lack of control and require knowledge of objective function attributes. This study proposes a framework using Gaussian process regression and artificial neural networks to generate innovative solutions in the ROI. By employing diverse sampling techniques and integrating long term memory, the framework can produce more than twice as many solutions in the ROI, as demonstrated in experiments with real-world problems and various benchmark functions.
Abbott Elementary’s principal Ava Coleman - a contrast for Black female administrators
(2022-11-01) Elango, Gillian; Petrarca, Diana
Using Mikos’ (2014) film analysis technique, the role of Ava Coleman in the mockumentary sitcom Abbott Elementary is dissected and contrasted to the researched experiences of Black women principals. The research on Black Female administrators provides a starting point of contrast in examining stereotypes and leadership styles. Further, comparisons are also reviewed based on findings of media portrayals of Black women and school principals. All thirteen 23-minute episodes of the series' first season provide the data source for research. Using Hill Collins's (2000) Black Feminist Theory framework, implications regarding the ability of the role to offer a differing narrative of what it means to be a Black woman in educational leadership are realized.
Academic integrity policy and support provisions: are Ontario colleges setting international and multilingual learners up for success?
(2022-07-01) Gibson, Steacy D.; Eamer, Allyson
With the meteoric rise of international students on college campuses across Ontario, institutions must be committed to provide support and continued discourse around multiple educational and cultural perspectives. One area of concern that has been overlooked in the literature is how international students are supported in understanding academic integrity from a western perspective. Through a mixed-methods approach, an investigation of the academic integrity policies and available support was conducted on each of Ontario’s 24 publicly funded colleges. Additionally, relationships between regional international enrolment and academic integrity support were analyzed. Findings suggest that most colleges in Ontario do not meet the exemplary elements of academic integrity policy and fail to support their international students to access and understand academic integrity policy. It is suggested that colleges invoke a more holistic approach to academic integrity, involving the voices of the international community to encourage a more anti-deficit and equitable understanding of academic integrity from a western perspective.
Academic success courses at Ontario colleges: a qualitative analysis of syllabi
(2020-07-01) Parsons, Jesse A.; Campbell, Brian; Hunter, Bill; Stokes, Joe
Ontario Colleges expanded enrolment and reached into populations that traditionally did not attend post-secondary (Rae, 2005). The challenge has been to support students who were not prepared for college-level academic work (Habley, Bloom & Robbins, 2012). Lennon, Skolnik and Jones (2015) pointed out that colleges have been providing curriculum arguably of high school equivalency. First-semester academic success courses have been a curricular response to these challenges. Academic success courses are a combination of learning skills, involvement, metacognition, motivation, and self-regulated learning (Tebe, 2007; Burchard & Swerdzewski, 2009; Rasmussen, 2013; Hoops, Yu, Burridge & Wolters, 2015). There does not exist a set or taxonomy of skills and student development concepts described in academic success course outlines from across the Ontario colleges. To fill this gap, I qualitatively categorized skills and student development concepts described within academic success course outline documents from across Ontario. The first step was a comprehensive scan of college program websites to determine the programs that incorporated an academic success course. Fifty-nine course outline documents were acquired for a content analysis of course descriptions and learning outcomes. The categorization of skills and concepts was based on a synthesis of literature on academic success, academic competencies, and the demands of industry. 304 programs incorporated an academic success course. Academic success courses were used in all college credentials. Results suggested that courses are widely used, though less so in the advanced credentials. Some courses were structured generically and applied across a range of programs while other courses were offered within programs using discipline specific language (e.g., business, heath). A qualitative content analysis revealed dominant course themes of academic skills and personal development. Learning outcomes seldom expressed reading and writing skills. Learning outcomes seldom expressed connecting to the college environment or services. Learning outcomes seldom expressed aspects of resourcefulness or resiliency. Recommendations for curriculum designers to address gaps in learning outcomes are offered. Further research is suggested to clarify the nature and use of academic success courses at the Ontario colleges.
Access control obligation specification and enforcement using behavior pattern language
(2018-01-01) Sharghigoorabi, Mohammadhassan; Liscano, Ramiro
Increasing the use of Internet-based devices offers novel opportunities for users to access and share resources anywhere and anytime so that such a collaborative environment complicates the design of an accountable resource access control system. Relying on only predefined access control policies based on an entity's attributes, as in traditional access control solutions, cannot provide enough flexibility to apply continuous adjustments in order to adapt to any kind of operative run time conditions. The limited scope and precision of the existing policy-based access control solutions have put considerable limitations on adequately satisfying the challenging security aspects of the IT enterprises. In this research, we focus on the obligatory behavior that can play an important role in access control to protect resources and services of a typical system. Since traditional access control is performed only once before the resource is accessed by the subject, the access control system is unable to control the fulfillment of obligation while the access is in progress. Practically, such a requirement is implemented in hard-coded and proprietary ways. Consequently, the lack of sophisticated means for specification and enforcement of obligation in access control system decreases its flexibility and may also lead to the security breach in sensitive environments. We provide a descriptive language that is capable of defining a variety of complex behavior patterns based on a sequence of user actions. Such a description can be used to specify different elements of the obligation in order to attach to a policy language, and it is also used to generate queries for behavior matching purposes. Moreover, we propose a behavior pattern matching framework to approve the fulfillment of the obligation by looking into the audit logs. However, this method is extremely inadequate for ongoing obligations. Therefore, we proposed a compliance engine by utilizing complex event processing in order to make a decision to revoke or continue the access in a timely manner. We implemented both frameworks that can be used to approve the obligation fulfillment as well as to evaluate the expressive power and complexity of our proposed language.
Achieving high efficiency thermoelectric heating and cooling with metal foam heat exchangers
(2014-04-01) Clark, Gavin; Rohrauer, Greg
This thesis examines the development of a high efficiency heat pump system using thermoelectric (TE) and reticulated metal foam (RMF) technologies to power a vehicle`s battery thermal management system. The focus is split into two areas: first a review of TE’s sourcing or removing heat, second an examination of compact heat exchanger (HX) design. Five TE suppliers were investigated to understand the performance and limitations of their TE modules. Testing showed the Kyrotherm product to be superior so it was used as a design basis. RMF’s are known to be an effective means to improve the performance of compact heat exchangers, thus HX’s were evaluated with RMF foams compressed to varying densities in order to understand their potential in conjunction with thermoelectric devices. Experimental results showed performance was limited due to adequate bonding, yet still on par with the highest efficiency technologies currently on the market.
Achieving real-time video summarization on commodity hardware
(2018-04-01) Taylor, Wesley; Qureshi, Faisal
We present a system for automatic video summarization which is able to operate in real-time on commodity hardware. This is achieved by performing segmentation to divide a video into a series of small video clips, which are further reduced or eliminated with the assistance of highly efficient low-level features. A numerical score is then assigned to each segment by our model trained using a set of highperformance hand-crafted features. Finally, segments are selected based on their score to generate a final video summary. On our benchmark dataset, we achieve results competitive to other methods. In cases where our accuracy is lower than competitive methods, we achieve significantly higher performance. We additionally present methods for generating additional summaries almost instantly, and for learning user preferences over time—two processes which are often overlooked in work on video summarization, but essential for real-world use
Acknowledging offender trauma at intake: a qualitative thematic analysis of Canadian correctional policy
(2023-08-01) Quinn-Hogan, Ashlee; Dhungana-Sainju, Karla
Trauma has seldom been discussed in the literature in relation to incarceration. The research that does exist has tended to be gendered, focusing predominantly on the trauma experiences of female offenders. The current study examined the written policies that guide the Offender Intake Assessment (OIA) process in Canada to assess the extent to which trauma is being considered at point of intake, particularly for male offenders. A descriptive research design was used to assess the level of policy specific attention given to trauma and trauma-informed correctional care (TICC). An examination of current policies, audits/reviews, and action plans revealed 11 key themes. The results of this study reveal a need for improved policy guidelines for addressing the trauma experiences of male offenders in Canada. Implications, limitations, and future directions are also considered
Active balancing of lithium-ion cells for maximum power discharging
(2018-07-01) Capano, David; Williamson, Sheldon
The future of Electric Vehicle’s (EV) depends on the adoption of the technology. Currently the limiting factor for EV adoption is mainly the initial cost, the driving range, charging capability, and the battery life. The Battery Management System (BMS) in any Lithium chemistry battery system is used to keep the cells in the optimal operating conditions. The BMS in standard EV batteries employ series cell balancing only while charging. The discharge balancing technique can be used to increase useable capacity from an EV battery because at the end of a cycle the stronger cells have some remaining capacity which can used to assist the weaker cells. This work explores the difference in useable capacity with active cell balancing vs. passive balancing for both new and aged cells near End of Life (EOL). In this work the proposed discharge balancing technique has been researched, simulated, and implemented in hardware testing.
Active transport and concentration of analytes in microfluidic paper based analytical devices using ion concentration polarization
(2019-04-01) Crowley, Michael; MacDonald, Brendan
Microfluidic paper-based analytical devices (µPADs) have a high potential for miniaturizing complex testing functions, since they are inexpensive, disposable, and portable. Paper has the advantage over traditional fluid channel systems in that it houses capillary-driven flow, which requires no external pumps or equipment. However, these paper-based devices have one disadvantage in that they do not enable further flow of fluids after becoming fully wet. In this work, active transport and concentration of analytes in fully wet paper-based assays is demonstrated by leveraging ion concentration polarization (ICP). The efficacy of ICP-inducing µPADs is demonstrated through transporting and concentrating dye, fluorescein and immunoglobulins. The application of actively concentrating immunoglobulins - antibodies with sample concentrations that are typically below traditional limits of detection - is a novel application of ICP and can be used to create universally accessible allergy tests.
Acute cardiopulmonary responses to different intensities of exercise in healthy older adults
(2019-12-01) Linares, Andrea; Dogra, Shilpa
The overall purpose of this thesis was to study the acute cardiopulmonary responses to different intensities of exercise in healthy older adults. Thirty healthy older males and females (69.6 ǂ 6.2 yrs.; males n = 15) underwent maximal exercise testing to determine maximal oxygen consumption (VO2MAX) and peak power output (PPO), and completed each of the following exercise protocols in a randomized crossover design: high intensity interval exercise (HI; 1 minute 90% PPO followed by 1 minute 10% PPO, x10), continuous moderate intensity exercise (MOD; 20 minutes at 50% PPO), and sprint intensity interval exercise (SPRT; 20 second “all-out” sprints followed by 2 minutes of 50W, x3). Oxygen consumption (VO2), ventilation (VE), tidal volume (Vt), respiratory rate (RR), heart rate (HR), tissue saturation index (TSI) of the vastus lateralis and rated perceived exertion (RPE) were monitored during exercise sessions. Heart rate recovery (HRREC) was assessed after each exercise session and heart rate variability (HRV) was compared using resting and post-exercise values. Overall, it was found that high fit individuals attained the greatest VO2 peak during MAX while low fit females attained a larger VO2 peak during SPRT compared to MAX. The rate of HRREC was greatest in high fit males. These findings have important implications for the individualization of exercise prescription, Future research will need to compare the three different types of exercise training to determine which protocol leads to larger adaptations in older adults.
The acute response to high intensity interval exercise in adults with exercise induced bronchoconstriction
(2016-05-01) O'Neill, Carley; Dogra, Shilpa
INTRODUCTION: Exercise induced bronchoconstriction (EIBC) occurs as a result of airway cooling and drying in adults with airway hyperresponsiveness (AHR). Continuous exercise leads to a significant decline in lung function; however, interval exercise may allow ventilation to recover and prevent EIBC. PURPOSE: To determine the acute response of lung function and the subjective perceptions during and after a bout of high intensity interval (HIIE), moderate intensity interval (MIIE), and moderate intensity continuous (MICE) exercise in adults with AHR. METHODS: Participants completed an acute bout of HIIE, MIIE, and MICE. Lung function was assessed pre and post-exercise while late phase symptoms were reported using a log and subjective responses were assessed during each minute of exercise. RESULTS: Thirteen participants with EIBC completed all protocols. Lung function was significantly lower following the MICE and perceptions of effort and dyspnea were higher. CONCLUSION: It appears HIIE is well tolerated among adults with AHR.

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