title: Optimization of residential buildings and renewable energy integration in small island developing states: the Bahamas as a case study

contributor:
Agelin-Chaab, Martin
Rosen, Marc

subject:
Bahamas
Optimization
Residential
Renewable energy

abstract:
An optimization approach is used to assess the energy performance and design of residential homes in The Bahamas with the goal of providing objective data for policy makers to achieve the sustainability goals in the country. EnergyPlus and jEPlus+EA provide the platform for this study, implementing the non-dominated sorting genetic algorithm II (NSGA-II) for optimization. Optimal solutions are compared to a building model developed from audited data.
The results indicate that design alternatives presented here can be feasibly implemented that possibly achieve net zero energy and carbon negative status. The peak reduction in life cycle costs is 42%, in building energy consumption is 30%. Additionally, the optimal R-values in the wall and roof constructions vary between 5-15, and 7-25, respectively. It was also shown that tariff rates have little effect on the construction of buildings, but has a larger impact on the integration of photovoltaics and battery storage.


title: Relative age effects: exploring possible solutions and the relationships between relative age, sport participation, education, and indicators of positive youth development

subject:
Relative age effects
Sport
Youth
Education
Connectedness

abstract:
Relative age occurs when youth are placed into age groups in sport and education. Relative Age Effects (RAE) indicate that being born closer to the cutoff date holds an advantage in sport and academic outcomes. Study 1 explores what effects relative age has on educational achievement, participation in school and extracurricular sport and physical education, and positive youth development (PYD). Methods. A secondary analysis of Ontario secondary school students (N= 22,915) age 13 to 18 from the COMPASS study was carried out. The influence of relative age on academic achievement, sport and physical activity participation, and feelings of connectedness were considered. Results. Statistically significant relationships were found between relative age and academic achievement in math and English, relative age and sport participation, and relative age and feelings of connectedness. Feelings of connectedness were related to sport participation as well as higher academic achievement, for all quartiles. Study 2, a systematic review of the relative age literature between January 1980 and May 2016, aimed to assess the strengths and weaknesses of various proposed solutions to relative age effects (RAEs) in youth sport. Results.
Forty-one peer-reviewed publications and three articles from online sources met the criteria for inclusion. Most solutions were theoretical and the majority of solutions proposed attempt to address environmental constraints (rather than task or individual) and seek to change sport systems or alter cut-off dates. Many of the solutions proposed would also be difficult to implement. Conclusions: Future research should seek to investigate the effects of relative age on youth sport and educational outcomes, especially as related to connectedness and PYD, and the consideration of other multi-dimensional aspects of youths’ developmental ecology. Future research should also seek to test possible proposed solutions to RAEs in sport.

abstract: University of Ontario Institute of Technology


title: Understanding the carbon morphology in sulfonated-silica ceramic carbon electrodes for the PEM fuel cell device

subject: Proton exchange membrane fuel cell

subject: Sulfonated silica ceramic carbon electrodes

subject: Catalyst layer

subject: Ordered mesoporous carbon

subject: Clean energy device

abstract:
Using hydrogen and oxygen gas, the fuel cell is a device that converts chemical energy into electrical energy. Particularly, the proton exchange membrane fuel cell, has multiple components, all that are consistently being studied in order to further increase its practicality. One particular limitation of the fuel cell is the use of the precious metal Pt within the catalyst layer. Efforts in decreasing the amount of Pt has provided information on improved utilization of the catalytic metal. Another limitation can be attributed to the perfluorosulfonated ionomer Nafion®, that is commercially available and used as a binder within the catalyst layer. The high cost and poor durability of current fuel cell catalyst layers has been linked to the use of Nafion® and the amount of carbon in the catalyst.
In this work, 40 wt% Pt/C catalyst is used to obtain total electrode loadings as low as 0.2 mgPt cm-2, with the hypothesis of increased energy density while reducing catalyst layer thickness. This catalyst is used in conjunction with a Nafion®-replacement ionomer that contains sulfonated silica, and provides comparable performance while increasing durability. This work also includes the substitution of the typical carbon support, Vulcan, with ordered mesoporous carbon. In order to grasp a better understanding of the catalyst as a whole, mesoporous carbon will be used in efforts of obtaining more uniform Pt dispersion and greater catalytic activity. With a successful synthetic route of the mesoporous carbon, further studies are required for enhanced Pt deposition techniques on the two-dimensional support.


title: Publish-subscribe based middleware for heterogeneous critical infrastructure systems communication.

contributor:
Heydari, Shahram
Sood, Vijay
El-Khatib, Khalil

subject:
Critical infrastucture
Publish-subscribe
Interdependency
OMNET++

abstract:
Critical Infrastructures (CIs) are physical assets and organizations responsible for the production and distribution of society’s vital goods and services. The increasing interconnection of CIs has resulted in interdependencies which effect the propagation of failure from one infrastructure to another. Therefore a publish-subscribe based communication system for dissimilar CIs is presented.
The proposed system improves the manageability of CIs by providing an exchange medium for status information and alerts. It achieves this via a uniform architecture within and across infrastructure boundaries, that maintains data restrictions that reflect real life organizational, administrative, and policy boundaries.
Finally the proposed system is modeled using the OMNET++ simulation framework, and a network performance study investigating scalability is presented. Scalability was found to depend on service time per packet, subscription density, and number of clients per router. However, further work in the areas of QoS management, reliability/robustness, security, and network optimization is required.


title: Object-centric temporal navigation for dynamic information visualizations.

subject:
Information visualization
Time navigation
Interaction

abstract:
We introduce object-centric temporal navigation for time-varying information visualizations.
In our approach, navigation through time is controlled by interacting directly with
any data item, enabling simultaneous exploration of the time dimension while focusing on
the changing item. Subtle visualizations of a data item’s temporal trend are provided to
guide navigation. To demonstrate how object-centric navigation can be designed for different
types of dynamic visualizations, we created two techniques: DimpVis, for exploring
changing visual variables in different information visualizations, and Glidgets, for exploring
topological changes in dynamic graphs. Both techniques enable intuitive investigation
of spatial queries. For example, using DimpVis to answer “Was this bar ever at 500?” in an
animated bar chart, one simply has to drag the bar to that height. Comparative task-based
evaluations revealed that DimpVis was quantitatively competitive to existing navigation
techniques. Additionally, both Glidgets and DimpVis were overall subjectively preferred
over the time slider by participants.


title: Machine learning classifiers for critical cardiac conditions

contributor:
Eklund, Mikael
Makrehchi, Masoud

subject:
Machine learning
Congestive heart failure
Atrial fibrillation
Heart rate variability
Electrocardiogram (ECG)

abstract: Cardiac diseases are one of the leading causes of death in Canada. Current methods of diagnosing cardiac conditions require a manual and visual analysis of ECG and heart rate (RR interval) data. In this thesis, novel features and machine learning classifiers are developed for automating the detection of Congestive Heart Failure (CHF) and Atrial Fibrillation (AFIB). These classifiers can potentially trigger alarms when implemented in wearable devices. In the first experiment, quantitative analysis of easily measurable RR interval data is employed to detect the change in CHF severity. This experiment demonstrates that for a progressive disease such as CHF, 6 hour RR interval data can be used to classify CHF severity. It shows that the separating patients in the least severe class from more severe classes performs better than the separating all three severity classes. AFIB is one of the most frequently occurring critical event that occurs in patients with CHF. The second experiment uses novel features extracted from RR interval data, to detect AFIB within the first minute of its occurrence. This experiment evaluates feature sets engineered through different feature selection techniques. The sensitivity and specificity of the proposed classifier is 98% and 95% respectively. The third experiment aims to identify subjects at a high risk of experiencing AFIB in the future. This experiment develops novel features using RR intervals and ECG signal analysis. The results show that feature sets obtained from ECG signals can improve the classifier performance (92.4% sensitivity and 82.8% specificity). However, classifiers based on RR interval alone also show high sensitivity and specificity (81.4% and 76.9% respectively).


title: Predicting the threat of death in stalking cases through Artificial Neural Network

subject:
Stalking
Threats
Variables
Machine learning
Artificial Neural Network

abstract: Stalking is a complex phenomenon that needs to be explained through several frameworks of research. During the years, scientists from the psychological, criminological, psychological, and legal fields made important steps to understand the nature of Stalking to find how to stop this type of behavior. The new concept that this research introduces is the possibility to predict if there will be the threat of death against a victim by a stalker through Artificial Intelligence and, more specifically, using an Artificial Neural Network (ANN). The thesis analyses variables impact on the learning process and the accuracy of this new system about predicting the threat of death. Publicly available and collected into the database Violence and Threats of Violence Against Women and Men in the United States built by Tjaden and Thoennes, the secondary data have been analyzed through the ANN. The result showed that variables impact fully support the theories, and the prediction of the threat of death against the victim is possible in this simulated environment with real data.


title: Simulation, design and construction of a gas electron multiplier for particle tracking

subject:
Stopping power
Gas electron multiplier
GEM
Particle tracking

abstract: The biological effects of charged particles is of interest in particle therapy, radiation protection and space radiation science and known to be dependent on both absorbed dose and radiation quality or LET. Microdosimetry is a technique which uses a tissue equivalent gas to simulate microscopic tissue sites of the order of cellular dimensions and the principles of gas ionization devices to measure deposited energy. The Gas Electron Multiplier (GEM) has been used since 1997 for tracking particles and for the determination of particle energy. In general, the GEM detector works in either tracking or energy deposition mode. The instrument proposed here is a combination of both, for the purpose of determining the energy deposition in simulated microscopic sites over the charged particle range and in particular at the end of the range where local energy deposition increases in the so-called Bragg-peak region. The detector is designed to track particles of various energies for 5 cm in one dimension, while providing the particle energy deposition every 0.5 cm of its track. The reconfiguration of the detector for different particle energies is very simple and achieved by adjusting the pressure of the gas inside the detector and resistor chain. In this manner, the detector can be used to study various ion beams and their dose distributions to tissues. Initial work is being carried out using an isotopic source of alpha particles and this thesis will describe the construction of the GEM-based detector, computer modelling of the expected gas-gain and performance of the device as well as comparisons with experimentally measured data of segmented energy deposition.


title: Analysis, development, and control of multi-degree-of-freedom passive haptic devices

subject:
Haptics
Force-feedback
Passive actuators
Brakes
Performance metrics

abstract: Stability and transparency are key design requirements in haptic devices. Replacing conventional electric motors with passive actuators such as brakes or dampers can improve both stability and transparency as passive actuators can display a wide range of impedance while guaranteeing stability. However, passive haptic devices suffer from a serious drawback; their force output is difficult to control. This issue was addressed extensively for planar manipulators but devices with higher degrees-of-freedom (DOF) have not been examined. This thesis proposes a generalized framework for analyzing and controlling higher-DOF devices and examining the effects of the kinematic structure on the force output capability. A first of its kind 3-Degree-of-Freedom (DOF) parallel passive haptic device was developed along with a novel controller designed specifically for the 3-DOF passive device. This thesis also investigates the use of a nonlinear disturbance observer to aid in the control of passive haptic devices.


title: The development and evaluation of a mHealth nutrition education intervention

subject:
mHealth
Child nutrition
Nutrition education
Food literacy
Gamification

abstract: An environmental scan of the app marketplace evaluated publicly available mHealth nutrition apps targeted to children and found that there were few high-quality evidence-based apps available to educate children on healthy eating. To fill this gap in the availability of mHealth child nutrition apps, an iterative multi-method approach was taken to develop a novel app, Foodbot Factory, to help children aged 9-12 improve their food literacy skills and nutrition knowledge. Foodbot Factory was created by an interdisciplinary team with each prototype being informed by data collected in 5 iterative user testing sessions. The app educates users on foods and nutrients, integrating behaviour change and gamification techniques to enhance engagement. Data from the most recent testing session demonstrates that students are able to gain knowledge about nutrition from Foodbot Factory and that the app is an engaging, usable, and acceptable intervention for children to learn about healthy eating and nutrition.


title: Modified constraint-induced movement therapy in a day camp for children with spastic hemiplegic cerebral palsy: intervention effects and consideration of personal factors

subject:
Spastic hemiplegic cerebral palsy
Constraint-induced movement therapy
Child-therapist alliance
Child-therapist interaction
Motor intervention

abstract: Constraint-induced movement therapy (CIMT) has been demonstrated to yield functional improvements for children with spastic hemiplegic cerebral palsy (CP); however, many studies have reported inconsistent findings with regards to the extent of the benefits observed following the intervention. This study sought to examine the effects of CIMT in the context of a day camp in this population; it also examined the child-therapist (C-T) interaction during the assessment sessions as a potential factor influencing the child’s scores on tests of motor performance. This interaction has not yet been formally measured in the literature, and may influence the perceived outcomes of CIMT. Motor Outcomes: Results demonstrated significant improvements in quality of use of the upper extremity following the intervention; the improvements were maintained at the 3-month follow-up. Analysis of each individual participant yielded additional information on clinically significant improvements. C-T Outcomes: Results demonstrated that the strength of the C-T interaction was significantly and positively correlated with the scores obtained by participants on motor assessments. The results of this study indicate that modified CIMT is effective in inducing lasting and meaningful changes in children with spastic hemiplegic CP. They also suggest that the C-T interaction may contribute to a participant’s performance during the assessment session, which may ultimately affect the perceived outcomes of CIMT.


title: Chronic effects of single intra-peritoneal injection of endosulfan on rainbow trout (Oncorhynchus mykiss) and field observations of caged rainbow in Oshawa Creek

contributor:
Holdway, Douglas
Bonetta, Dario

subject:
Organochlorine pesticide endosulfan
Rainbow Trout
Endocrine disrupting chemical
Oshawa Creek

abstract:
The organochlorine pesticide endosulfan has been shown to be highly toxic to fish
and there is some evidence to support that it may act as an endocrine disrupting chemical.
Juvenile rainbow trout (Oncorhynchus mykiss) were caged at 4 sites in Oshawa Creek
during the fall and spring of 2008 and 2009 while another group was intra-peritoneal
injected in the laboratory with varying concentrations (ppm) of endosulfan. Plasma
vitellogenin (VTG) levels, liver ethoxyresorufin-O-deethylase (EROD), citrate synthase
(CS), lactate dehydrogenase (LDH), and brain acetylcholine esterase (AChE) (caged fish
only) enzymatic activities were measured. Trout injected with endosulfan experienced an
increase of the anaerobic (LDH activity) and a decrease of the aerobic (CS activity)
metabolic pathways, while male VTG levels increased. Since it was a singular injection,
VTG results have to be confirmed. Fall caged trout showed increased EROD activity and
inhibited AChE activity while those caged in the spring experienced an unexpected
exposure to the lampricide 3-Trifluoro-Methyl-4-Nitro-Phenol (TFM) which disrupted
metabolic parameters (inhibited CS and increased LDH activity). Both fall and spring
caged trout experienced no induction of VTG activity. Further research is needed since
the spring exposure was altered due to the unplanned TFM treatment and thus did not
represent a valid temporal replicate.


title: Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients

subject:
Reactor physics
Diffusion theory
Heavy water reactors
Natural uranium
Core reflector interface

abstract:
To model the neutronic physics behavior of the core in CANDU pressure tube type heavy water reactors with natural-uranium fuel, two levels of calculations are required. Initially, lattice-level transport calculations are carried out to obtain, with high detail and accuracy, the flux distribution inside the lattice cell and composition of the nuclear fuel. Lattice calculations use many (30- 180) energy groups and detailed geometric information to model the fuel channel and the fuel contained within.
Once the lattice calculations are complete, the fuel compositions obtained can be used to generate cell-homogenized macroscopic cross-sections condensed to two energy groups, for use in full-core diffusion calculations. Two-group cell-homogenized cross-sections work to acceptable levels of accuracy in most full-core configurations. However, challenges appear when modelling the neutron flux at the fuel-reflector interface (at the boundary of the reactor).
This work aims to improve the neutron flux estimates obtained in three-dimensional diffusion calculations by using diffusion coefficients fitted to transport results. It will be shown that significant improvements (>10%) can be made for modeling the neutron physics at the core-reflector interface.


title: Design and construction of a one-dimensional particle tracker for measurement of alpha particle stopping power

subject:
Radiation
Health physics
Alpha particle
Stopping power
Gas electron multiplier

abstract:
The energy deposited by a charged particle in a medium is non-uniform and peaks near the end of the particle’s path. The energy deposition through the medium is known as stopping power and the shape of this function is called the Bragg curve. Stopping power is typically calculated from first principles rather than measured due to the difficulty of doing so.
A one-dimensional particle tracker using gas electron multiplier technology was designed and constructed to directly measure the stopping power at 16 discrete points along the path of alpha particles emitted by 241Am. The use of tissue-equivalent gas allows the results to be compared to those expected within tissue.
The results obtained show that the detector concept has merit, although there is room for improvement. In particular, certain voltages and electric field strengths have room for optimization, and more sophisticated readout electronics could be used to reduce experiment run time.


title: Life cycle assessment of conventional and alternative fuels for vehicles

subject:
Life cycle assessment
Vehicles
Fuels
Hydrogen
Electric vehicles

abstract: For the near future, it is important that vehicles are run by alternative fuels. Before we can go ahead with the new alternatives, it is crucial that a comprehensive life cycle analysis is carried out for fuels. In this thesis study, a cradle-to-grave life cycle assessment of conventional and alternative fuels for vehicle technologies is performed, and the results are presented comparatively. The aim of the study is to investigate the environmental impact of different fuels for vehicles. A large variety of fueling options, such as diesel, electric, ethanol, gasoline, hybrid, hydrogen, methane, methanol and natural gas are considered for life cycle assessment of vehicles. The study results are shown in abiotic depletion, acidification, eutrophication, global warming, ozone layer depletion and human toxicity potential using three different impact assessment methods. The analyses show that hydrogen vehicle is found to have the lowest environmental impacts with ozone layer depletion of 8.14×10-10 kg CFC-11-eq/km and the human toxicity potential of 0.0017 kg (1,4 DB)-eq/km respectively. On the other hand, the gasoline-powered vehicle shows a poor performance in all categories with the global warming potential of 0.20 kg CO2-eq/km.


title: Evaluating the impact of real-time visualization on knowledge acquisition in management meetings

subject:
Visualization
Visual practitioner
Manager
Meeting
Knowledge acquisition

abstract: This thesis study examines the use of real-time visualization in management meetings to determine how visualization affects knowledge acquisition. The participants in this research are 33 business managers and visual practitioners (n=33) located across five continents who have previously worked with real-time visualization techniques in management meetings. Using a mixed-methods case study design, this research investigated how corporate managers share information in the workplace with visualization tools in real-time. In particular, this research examined how visualization can be used to support knowledge sharing, knowledge creation and knowledge documentation. Key findings indicate that 75.8% of participants report a positive effect of visualization on knowledge acquisition. The different visualization processes used in management meetings are discussed. Future work in this area could investigate how the corporate manager and the visual practitioner could create synergies to embrace interactive visualization processes in management meetings.


title: “Taking a chance and striking out”: an exploration of homelessness, housing pathways, and ‘self-sabotage’

subject:
Homelessness
Housing pathways
Housing stability
Self-sabotage

abstract: Homelessness remains a prevalent social issue in Canada, though limited research has sought to explore the process of transitioning from homelessness to housing. Exits from homelessness are rarely straightforward and are obstructed by the prevailing discourses that entrap identity within homelessness, making it difficult to establish a new sense of self after obtaining housing. The phenomenon of self-sabotage offers insights into the conscious and unconscious forces that drive individuals to engage in behaviors that may obstruct their chances at achieving desired goals. This thesis provides insights from individuals with lived experience of homelessness regarding the challenges they feel impede housing stability. Findings suggest that discourses of homelessness contribute to identity and result in continued engagement in the expected behaviors of this social category, jeopardizing housing stability.


title: Proposing effective coordinate search methods for solving large-scale expensive black-box optimization problems

subject:
Coordinate-search
Gradient-free
Non-convex
Neural-network
Large-scale optimization

abstract: In engineering and science, optimization plays a vital role in many real-world applications. In this work, several novel optimization algorithms based on Coordinate Search (CS) algorithm are proposed. CS is a gradient-free technique and we have enhanced them for solving Black-box, non-convex, and expensive large-scale problems. These CS-based algorithms can handle mixed-type variables. When an optimization problem is large-scale and expensive, it is a very challenging problem to solve because it is intersecting two conflicting properties. Large-scale problems require extensive fitness evaluations, but each evaluation is time consuming. It gets more challenging when the budget is limited, which is the case in most real-word applications. The proposed CS-based algorithms reduce the search space exponentially; this makes it a powerful method for optimizing high-dimensional problems with limited budget. The proposed algorithms show a very promising performance on optimizing high-dimensional problems; tested on the CEC-2013 benchmarks problems and neural network training.


title: A system framework for non-intrusive monitoring of HMI states for detecting human-in-the-loop error precursors

subject: Auto Regression Integrated Moving Average (ARIMA)

subject: Computer vision

subject: Human Machine Interface (HMI)

subject: Human-in-the-loop (HITL) error

subject: Long-Short Term Memory (LSTM)

abstract:
Past industrial accidents suggest that increased automation has had an adverse effect on operator situational awareness (SA) and Human-in-the-Loop (HITL) errors. More so, any current automation is not yet capable of providing the level of situational awareness that a human operator can provide and close the ethical responsibility-gap.
The objective of this research is to design a system for detecting HITL error precursors to ascertain operator SA (as a function of operator activity index) in real-time via non-intrusive monitoring. The proposed system frameworks are ViDAQ and EYE-on-HMI. ViDAQ is a visual data acquisition system that uses computer vision techniques to capture dynamic visual feedback from the industrial human-machine interface (HMI) (e.g., control panels) states. For example, ViDAQ results demonstrate approximately 90% accuracy at 1 meter acquisition distance when reading a multi-dial rotary-style meter. Positive results, coupled with real-world control room settings that offer constant lighting and a vibration-free environment, support the future efficacy of ViDAQ.
The EYE-on-HMI is a novel expert supervisory system that models HMI state patterns (as captured from ViDAQ) under normal and abnormal conditions, to detect HITL error precursors in real-time. It is developed using a variety of modeling techniques: linear regression (ARIMA), recurrent, and convolutional neural network (RNN and CNN) for HMI time-series modeling; and Seq2Seq deep learning natural language processing (NLP) models for HMI discrete event system model. As an example, relative root-mean-square-error in forecast accuracy is RMSE ~ [30%; 80%; 100%] for N - ahead > 10 time-step forecast window. This suggests regression-based models are closely followed by RNN, CNN, and NLP models in order of forecast accuracy achieved using synthetic HMI state datasets. Nevertheless, RNN and CNN are more versatile and scalable than the regression models during the training and evaluation phases, which is also anticipated for large scale multi-variate industrial HMI datasets. Moreover, the NLP based models embed contextual dependencies as semantic relations between HMI states for complex event patterns to improve HITL error precursor detection accuracy.
Lastly, the proof-of-concept HITL error precursor detection using CANDUTM Nuclear Control Room Operator training simulator is demonstrated.

abstract: University of Ontario Institute of Technology


title: Exploring the interactional theory: a theoretical exploration of the dark web’s impact on delinquent behaviour

subject:
Darknet
Deviance
Marketplace
Illegal tool-kit
Community

abstract: Throughout the years, modern issues of delinquent behaviour have evolved and shifted from the advancements of technology and the development of the virtual world. Despite the possibility for this connection, research has exclusively concentrated on the disruption of product flow. This study looks to explore the development and significance of delinquent behaviour within the dark web. Using Thornberry’s (1987) Interactional theory, the study explores how the dark web manifested as a marketplace, illegal tool-kit, and virtual community impacts delinquent behaviour. The study conducts an exploratory case study on the illicit Whitehouse market to explore while the interactional theory is a useful theoretical approach that can account for the dark web as a marketplace, illegal tool-kit, and virtual community impacting delinquent behaviour, it fails to account whether or not the dark web impacts the weakening of normative social bonds to conventional society.


title: Enhancement of lateral stability of car-trailer systems using model-reference adaptive control

subject:
Car-Trailer safety
Lateral stability
Model Reference Adaptive Control (MRAC)
Linear-Quadratic Regulator (LQR)
Active Trailer Steering (ATS)

abstract: Car-Trailer (CT) systems exhibit reduced maneuverability in curved-path negotiations and display low lateral stability under high-speed evasive maneuvers. Therefore, the objective of this thesis is to design a Lyapunov-Stability-based Model Reference Adaptive Controller (MRAC) for an active trailer steering system to enhance the lateral stability of CT systems considering parametric uncertainties and unknown dynamics of the actuator. To this end, a reference model is designed using a 3-DOF (degrees of freedom) linear CT model with active trailer steering; the virtual vehicle, i.e., the nonlinear CT model with 22-DOF, is developed in CarSim software; the MRAC controller is constructed in Simulink/MATLAB. To explore the robustness of the Lyapunov-Stability-based MRAC controller with respect to uncertainties, co-simulations are carried out by integrating the virtual CT developed in CarSim, the reference model and MRAC controller designed in Simulink/MATLAB. Simulations reveal that the proposed controller adapts to external disturbances and parametric variations very well. Specifically, the research leads to the insightful finding that the adaptive controller based active trailer steering system can effectively improve the lateral stability of CT systems, and the proposed design methodology will provide a valuable guideline for the development of advanced active safety systems for CT systems in the future.


title: Perceptions of crime changes, well-being, and personal safety during the COVID-19 pandemic

subject:
Crime trends
Mental health
Work stress
COVID-19 pandemic
Safety

abstract: Ontarians have been greatly impacted by the COVID-19 pandemic in terms of their personal safety, well-being, and stress. As such, data was collected in January 2021 and surveyed 258 Ontarians to determine the effects that these factors have had on the public, and the public’s perceptions of crime changes from mid-March to mid-December 2020 and whether these perceptions were influenced by being an essential worker, gender, age, and minority status. Results found that stress was higher for essential workers during the first nine months of the pandemic. Overall crime was perceived to have remained the same, while child abuse, cybercrime, domestic violence, drug-related crime, financial crime, and hate crime were perceived to have increased. Female minority respondents felt less safe during the pandemic and well-being was more negatively impacted for younger respondents. Overall, the study findings suggest that resources are needed to recover from, and be prepared for, future pandemics.


title: Model predictive control of a thermoelectric-based heat pump.

contributor:
Eklund, Mikael
Rohrauer, Greg F.

subject:
Model predictive controller
System identification
Thermal management

abstract:
Government regulations and growing concerns regarding global warming has
lead to an increasing number of passenger vehicles on the roads today that are not
powered by the conventional internal combustion (IC) engine. Automotive manufacturers
have introduced electric powertrains over the last 10 years which have
introduced new challenges regarding powering accessory loads historically reliant on
the mechanical energy of the IC engine. High density batteries are used to store
the electrical energy required by an electric powertrain and due to their relatively
narrow acceptable temperature range, require liquid cooling. The cooling system in
place currently utilizes the A/C compressor for cooling and a separate electric element
for heating which is energy expensive when the source of energy is electricity.
The proposed solution is a thermoelectric heat pump for both heating and cooling.
A model predictive controller (MPC) is designed, implemented and tested to
optimize the operation of the thermoelectric heat pump. The model predictive
controller is chosen due to its ability to accept multiple constrained inputs and
outputs as well as optimize the system according to a cost function which may
consist of any parameters the designer chooses. The system is highly non-linear and
complex therefore both physical modelling and system identi cation were used to
derive an accurate model of the system. A steepest descent algorithm was used for
optimization of the cost function.
The controller was tested in a test bench environment. The results show the
thermoelectric heat pump does hold the battery at the speci ed set point however
more optimization was expected from the controller. The controller fell short of
expectation due to operational restriction enforced during design meant to simplify
the problem. The MPC controller is capable of much better performance through
adding more detail to the model, an improved optimization algorithm and allowing
more flexibility in set point selection.


title: Are they right or wrong? Investigating the ability to judge the accuracy of eyewitnesses in same-and -other race identifications

subject:
Jury decision making
Eyewitnesses
Cross-race effect
Juror knowledge

abstract: Past research has investigated the cross-race effect in the context of eyewitnesses and jury decision-making. The main goal of my thesis was to gain further insight into participants’ knowledge of the cross-race effect and how this impacted participants’ discrimination of same- and cross-race identifications. One hundred fifty-nine undergraduate students from UOIT viewed a series of showup identification videos. I found that participants were better able to discriminate accurate from inaccurate same-race identifications than cross-race identifications. However, participants believed White witnesses more and found them more credible than South Asian witnesses. Further research should investigate other conditions that influence people’s abilities to discriminate accurate from inaccurate eyewitness identifications.


title: Evaluation of the bubble spectrometer performance in space-like neutron fields

subject:
Spectrometer
Space Bubble Detector
International Space Station

abstract: The Space Bubble Detector Spectrometer (SBDS) consists of six bubble detectors each with a different neutron energy threshold. To characterize the spectrometer in a space-like neutron field, a series of experiments were conducted with high-energy neutrons from 6.0×105 eV to 7.50 ×108 eV at the Los Alamos National Laboratory. The analysis of the obtained data provided a calibration factor to adjust the neutron sensitivity, to high-energy neutrons of the SBDS, based on its response function matrix. The results suggest that the SBDS underestimates the ambient dose equivalent in a space-like neutron field by a factor of approximately 1.55. Consequently, the readings of the spectrometer should be adjusted when used in a space radiation environment. This thesis is dedicated to studying the SBDS in a space-like neutron spectrum. It outlines a part of the results of international ground testing experimental sessions of the space instrumentation supported by the Canadian Space Agency.


title: Analysis and assessment of integrated waste-to-energy systems based on plastic wastes for multigeneration

subject:
Waste to energy
Plastic wastes
Pyrolysis
Gasification
Efficiency

abstract: This thesis proposes three wastes to energy multigeneration systems that are based on plastic wastes. The three systems are coupled with renewable energy resources like solar energy, geothermal energy, and wind turbine energy. The three systems are designed to convert plastic waste into five useful outputs of electric power, heating, fresh water, domestic hot water, and hydrogen. The proposed locations for the three systems are Cordoba, Spain for the first multigeneration system, Kakkonda, Japan for the second multigeneration system and Tarfaya, Morocco for the third system. The systems are analyzed thermodynamically and studied parametrically to identify optimum operating conditions. Energy and exergy analyses are performed to identify the efficiency of each system. According to the findings, the first system has the highest overall energy efficiency at 71.43%, while the second system has the highest exergy destruction rate 8,141.58 kW at the gasifier.


title: What’s in a name?: Revealing the function of the criminal pseudonym through a content analysis of ten characters in twelve films

contributor:
Grant, Judith
Downing, Steven
Cesaroni, Carla

subject: Pseudonym Identity Performance Media Subculture

abstract: At times, individuals articulate their criminal identity with the construction of a pseudonym derived from within their subculture. This study assumes there is a value and/or purpose in the construction, cultivation and representation of the criminal identity as expressed through the use of the pseudonym. This study, through the observation of 12 films, investigates the prevalence and functions of the pseudonym within the criminal subculture as represented in each movie. Basic descriptive values and a content analysis revealed that the pseudonym has a symbolic value to the characters, which contributes to an understanding of the multiple dimensions that constitute the criminal identity. This film analysis can be used to understand how both the individual’s concept of self is negotiated, as well as how the criminal justice system interacts with identity formation processes. I argue that the pseudonym articulates the criminal’s master status. The individual’s propensity to manage the criminal identity indicates that the deviant identity is primary or secondary in relation to their ‘official identity’. I argue that sociological conditions – family, peers, culture, prison, education - coalesce and influence identity formation processes.


title: Haptic controls in cars for safer driving

subject:
Haptic technology
Sense of touch
Haptic feedback

abstract:
With the spread of latest state of the art technologies geared towards utilization of the human senses, haptic technologies have been introduced as a way of utilising the sense of touch to either solve real world problems or to enhance present experiences. This thesis focuses on using haptic technology in cars to make the driving experience safer. Modern vehicles carry GPS, music systems, sunroofs and a number of other electronic gadgets. Interaction with these devices while driving often takes the driver‘s eyes ―off the road‖ and raises safety concerns. We are proposing a unique haptic design that uses the ‗sense of touch‘ as a mode of controlling or coordinating the various technologies and convenience devices found within a car. A pattern of distinguishable haptic feedback linked to a corresponding device allows the user to operate these devices through ‗sense of touch‘ and eliminates reliance on visual interaction.
This design will help to reduce the driver‘s distractions, as it will be installed in an easily accessible location such as on the steering wheel. A simulation has been done using a haptic interface ―i.e. desktop phantom to test the system‖ and a prototype has been developed which can be installed in any vehicle. This prototype has been tested to work with a limited number of convenient devices. However, further development and enhancements can be made to incorporate more devices and other user preferences. The main objective of this research is to integrate various functionalities in a robust manner, which will focus on the driver‘s safety by ensuring ―constant vision on the road‖. Distinguishable distinct haptic responses will act as unique depictions for specific convenient devices within the car, allowing the driver to interact and manipulate the settings of the device based on the detection and identification of the various unique haptic depictions.


title: Modelling and real-time simulation of a modular bidirectional solid-state transformer for ultra-fast charging of electric vehicles

subject: Ultra-fast charging of electric vehicles

subject: High-power multilevel converters

subject: CHB rectifier

subject: DAB

subject: SiC MOSFET

abstract: This thesis proposes a modular Solid-State Transformer (SST) system architecture to be directly interfacing with a three-phase MV utility network enabling high-power and ultra-fast charging capabilities for electric vehicles, with the capacity to incorporate energy storage systems at the MVDC-link. This topological configuration allows bi-directional power flow for Vehicle-to-Grid and for scalability to higher voltage and power levels. A detailed model-based design of a multi-module SST is presented with 3.3 kV SiC MOSFETs for highly efficient charging rated at 1.5 MW, supplied by a 27.6 kV distribution feeder. The SST switching model is based on a high-frequency two-stage power conversion solution with a Cascaded H-Bridge (CHB) rectification stage followed by a Dual Active Bridge (DAB) conversion stage. Control strategies and modulation schemes are implemented to achieve voltage balance and unity power factor, and to mitigate current harmonics and voltage ripples in compliance with IEEE standards, validated by Model-in-the-Loop real-time simulation.


title: Codebook design for distributed relay beamforming system

subject:
Beamforming
Codebook design
Lloyd's Algorithm

abstract:
In FDD amplify-and-forward distributed relay network, codebook techniques are utilized
to feedback quantized CSI with limited cost. First, this thesis focuses on the phaseonly
codebook and with-power-control codebook design methods under individual relay
power constraints. Phase-only codebooks can be generated off-line with the Grassmannian
beamforming criterion. Due to non-uniform distribution of the optimal beamforming vector
in the vector space, The Lloyd’s algorithm is proposed for with-power-control codebook
designs. To reduce search complexity, a suboptimal method for the codebook update stage
in the Lloyd’s algorithm is proposed. Its performance is compared to the performance of
the global search method which provides the optimal solution but incurs high computation
complexity. Second, this thesis investigates the performance difference between phaseonly
and with-power-control codebooks. It is found that the power control gain is tightly
related to the relay locations. When the relays are close to the source node, the gain from
power control is negligible and using phase-only codebooks becomes a viable choice for
feedback due to its simple implantation and off-line computation. Finally, the problem of
codebook design extends to the total relay power constraint case, and the Lloyd’s algorithm
with primary eigenvector method is proposed to design a suboptimal codebook.


title: An anomaly detection model utilizing attributes of low powered networks, IEEE 802.15.4e/TSCH and machine learning methods

subject:
Security
Ultra low powered networks
IEEE 802.15.4e/TSCH
Anomaly detection
Machine learning

abstract:
The rapid growth in sensors, low-power integrated circuits, and wireless communication standards has enabled a new generation of applications based on ultra-low powered wireless sensor networks. These are employed in many environments including health-care, industrial automation, smart building and environmental monitoring. According to industry experts, by the year 2020, over 20 billion low powered, sensor devices will be deployed and an innumerable number of data objects will be created.
The objective of this work is to investigate the feasibility and analyze optimal methods of using low powered wireless characteristics, attributes of communication protocols and machine learning techniques to determine traffic anomalies in low powered networks. Traffic anomalies can be used to detect security violations as well as network performance issues. Both live and simulated data have been used with four machine learning methods, to examine the relationship between performance and the various factors and methods.
Several factors including the number of nodes, sample size, noise influence, model aging process and classification algorithm are investigated against performance accuracy using data collected from an operational wireless network, comprising more than one hundred nodes, during a six-month period. An important attribute of this work is that the proposed model is able to implement in any low powered network, regardless of the software and hardware architecture of individual nodes (as long as the network complies with an open standard communication mechanism). Furthermore, the experiment portion of this work includes over 80 independent experiments to evaluate the behaviour of various attributes of low powered networks.
Machine learning models trained using carefully selected input features and other factors including adequate training samples and classification algorithm are able to detect traffic anomalies of low powered wireless networks with over 95% accuracy. Furthermore, in this work, a framework for an aggregated classification model has been evaluated and the experiment results confirm a further improvement of the prediction accuracy and a reduction of both false positive and negative rates in comparison to basic classification models.


title: Neuroimaging metrics of drug- and food-cue reactivity as a function of psychopathic traits, substance use, and substance dependence

subject:
Addiction
Psychopathy
fMRI
Neural processing
Corticolimbic

abstract: We conducted two fMRI studies assessing the relationship between psychopathy and drug- and food-related neural reactivity. In the first study, we assessed the relationship between psychopathic traits and neural reactivity among 47 cocaine-dependent and 58 non-dependent participants. The cocaine-dependent group exhibited a neural processing bias towards drugrelated stimuli within a corticolimbic circuit involved in decision-making, salience attribution, and motivation. Psychopathic traits both sensitized this neural processing bias and modulated the effect of substance use severity. In the second study, we separated dependent participants into psychologically- (n =25) or physiologically-dependent (n = 20) participants and observed a neural processing bias towards drug-related stimuli among physiologically-dependent participants alone. Interestingly, both psychopathic traits and substance use severity exhibited positive correlations to drug > food reactivity within psychologically-dependent participants. These results further our understanding of the comorbidity between psychopathy and addiction and help conceptualize a new comprehensive model for the development of addiction.


title: Ethylene response and phytohormone-mediated regulation of gene expression in Komagataeibacter xylinus ATCC 53582

subject:
Komagataeibacter xylinus
Bacterial cellulose
Plant-microbe interactions
Ethephon
Ethylene

abstract: Komagataeibacter xylinus ATCC 53582 is a fruit-associated, cellulose-producing bacterium that responds to and synthesizes phytohormones. This thesis elaborates on the ecophysiology of K. xylinus. Responses to indole-3-acetic acid (IAA), abscisic acid (ABA) and ethylene, produced in situ from ethephon, were of particular focus. The effect of these phytohormones on K. xylinus cellulose production and expression of cellulose biosynthesis-related genes (bcsA, bcsB, bcsC, bcsD, cmcAx, ccpAx and bglAx) were determined using pellicle assays and reverse transcription quantitative polymerase chain reaction (RT-qPCR), respectively. Ethylene enhanced cellulose yield by upregulating bcsA and bcsB expression, while IAA decreased cellulose yield by downregulating bcsA. Differential gene expression within the bacterial cellulose synthesis (bcs) operon is reported and a phytohormone-regulated CRP/FNR transcription factor was identified that may influence K. xylinus cellulose biosynthesis. Based on evidence provided in this thesis, the classification of K. xylinus as a saprophyte and its potential to accelerate fruit ripening in nature is proposed.


title: GURB : the game user research blueprint

contributor:
Mirza-Babaei, Pejman
Nacke, Lennart

subject:
Game design
User research
Mixed methods

abstract:
With the rise of new platforms, distribution and crowdfunding services, the game
industry is facing fast changes and advances in technology. Game development
studios are under more pressure to create successful games due to the increase
of competition and emerging technologies. The need for Games User Research
(GUR) is becoming more important in order to ensure that the player experience
matches with the game’s design intention. GUR helps validate experiences and
fix issues before they reach the mass market ensuring the highest quality player
experience through rigorous iterative evaluation.
This thesis presents an investigation into the triangulation of identifying the
design intent, measuring the player experience and communicating both in a single
document within the context of GUR. GUR studies the interaction between
the game and its users (players) to find where the design intention does not
match the player experience in order to provide feedback to the developers on
how to optimize the experience. A tool called Games User Research Blueprint
(GURB) is developed, which compares the design intent for a player experience
with the measured result of a user test in order to communicate issues with relevant
context. This thesis contributes to the field of Human-Computer Interaction
(HCI) and GUR in three important areas: (1) communicating design intent across
the multidisciplinary field of game development, (2) highlighting important challenges
when conducting GUR with small studios, and (3) the development of the
GURB tool for effectively communicating the results of a user test.
The contributions are described through case studies and interviews with game
developers. The results indicate that the GURB is an effective tool for facilitating
communication in a multidisciplinary field while delivering a clear and concise
summary of issues from a playtest in a timely and cost effective manner. The contributions in this thesis are directly applicable for user researchers, game developers,
and other user experience disciplines.


title: Spatial peripheral interaction techniques for viewing and manipulating off-screen digital content

subject:
Around-device
Off-screen
Spatial user interface
Spatial interaction
Human-computer interaction

abstract: When an information space is larger than the display, it is typical for interfaces to only support interacting with content that is rendered within its viewport. To support interacting with off-screen content, our work explores the design and evaluation of several spatial off-screen exploration techniques that make use of the interaction space around the display. These include Paper Distortion, Dynamic Distortion, Dynamic Peephole Inset, Spatial Panning, and Point2Pan. We also contribute a formalized descriptive framework of the off-screen interaction space that divides the around-device space into interaction volumes and analyzes them based on different factors. This framework guided the design of an off-screen interaction system, called Off-Screen Desktop, which implemented our spatial techniques using consumer-level motion sensing hardware. To enable a more detailed analysis of spatial interaction systems, we also developed a web-based visualization system, called SpatialVis, that visualizes log data over a video screen capture of the associated user interface.


title: Experimental investigation of a catalyst under various solar light conditions for hydrogen production.

contributor:
Dincer, Ibrahim
Naterer, Greg

subject:
Solar
Hydrogen
Photocatalyst
Absorption spectroscopy
Extinction coeffiecient

abstract:
The light absorption characteristics of the photocatalyst {[Ru(bpy)2(dpp)]2RhBr2}5+ and
the photochemical Ru(bpy)2(dpp)2+ is investigated. Extinction coefficient versus
wavelength is determined for both a low intensity broad spectrum LED light source and
one sun intensity simulated sunlight. Variation in the absorption characteristics from
both the previously published monochromatic values and from each other is observed.
absorption characteristics are dependent upon the type of light used and that specific
testing for the design wavelength range should be conducted so that the actual absorption
characteristics are then used to establish an optimum light absorbing configuration for
photocatalyst use. This technique is used to create a simulation model that is analyses the
distribution of hydrogen production rates in the existing test cell and demonstrates that
most of the hydrogen production occurs in a relatively small volume within the existing
test configuration. The absorption spectroscopy of the photocatalyst is found to change
after extended exposure to light. Two possibilities exist, transformation of the
photocatalyst to a different configuration and breakdown of the photocatalyst into
component parts. Degradation would explain observed changes in photocatalyst quantum
efficiency with time. A chemical model for water photocatalysis is proposed. In addition
to identifying several of the isomers that occur and explaining the changes in absorption
spectroscopy; it also addresses the impact of changing solution solvent on quantum
efficiency. It also addresses the apparent contradiction between photon supply rate and
molecular excited state lifetimes on photocatalytic ability.

abstract: University of Ontario Institute of Technology


title: The effect of language proficiency on second-language lie detection.

subject:
Deception detection
Second-language speakers
Discrimination
Bias

abstract:
I examined whether observers’ own language proficiencies would affect their lie
detection judgments. In a previous study, native- and second-language English speakers
were videotaped as they either lied or told the truth about having cheated on a test (Da
Silva & Leach, 2013). A total of 284 undergraduate students viewed the videos and were
asked to indicate whether they believed that the individuals were being truthful or
deceptive. Observers performed better when judging native-language speakers than
second-language speakers. Furthermore, observers’ own language proficiencies had an
effect on bias: as the proficiency of observers decreased, they were more likely to judge
speakers as truth-tellers. However, there was no effect of language proficiency on
discrimination. These findings may inform law enforcement hiring practices. In addition,
they suggest that the use of interpreters in legal processes may be essential. Implications
of these findings will be further discussed.


title: Development and investigation of compressed air only and hybrid powering options

subject:
Compressed air vehicle
Hybrid car
Exergy
Sustainable energy
Transportation

abstract:
Currently, significant resources are deployed to investigate electric and pneumatic vehicles in response to environmental, energy and consumer pressures. The goal of this thesis is to show conceptual development, analyze, performance assessment and comparative evaluation to further develop a pre-commercial design of compressed air vehicle. Three novel pneumatically or pneumatic-electric powered vehicles are developed, and energetic and exergetic performances given on the basis of different regimes, energy load, and climate conditions.
System 1 is a pneumatic only with three stage expansion air motors. It is important to reheat the air at inter-stages, because of two reasons, namely more work can be retrieved and icing of the exhaust pipe while air cools-down during expansion is avoided. This system takes required air for regeneration from outside. The energy and exergy efficiencies of System 1 are 63.0% and 45.0%, respectively. The results show that the driving range of first system car, is 198 km per full tank.
System 2 is a pneumatic only with two stage expansion air motors. It is important to reheat the air at inter-stages. This system takes required air for regeneration from low pressure tank to main storage tank. The energy and exergy efficiencies of System 2 are 68.0% and 47.0%, respectively. Expected driving range of pneumatic vehicle is depending on the vehicle size. The results show that the driving range of second system car, is 202 km per full tank.
System 3 is a hybrid electric and compressed air powertrain car with two stage expansion air motors. The powertrain integrates two power generation systems: electric and pneumatic (compressed air). Two stages expansion and reheating between stages with electric motors heat and at the same time cooling the electric windings with compressed air considered. The energy and exergy efficiencies of the System 3 are 72.0% and 51.0%, respectively. The expected driving range with hybrid driving range is 385 km per full air tank, and full charged battery.


title: Biochemical alteration of gravesoils between season and soil type

contributor:
Forbes, Shari
Carter, David

subject:
Decomposition
Gravesoil
Postmortem interval

abstract: Decomposition chemistry refers to the biochemical degradation processes which occur in soft tissue as decomposition proceeds. This study aims to investigate the relationship between the release of decomposition fluids into contrasting soil environments and their potential correlation with the presence of a decomposing carcass.  Soil from two different carcass decomposition trials was utilized to determine if seasonal and soil variation altered the soils reaction to a carcass.  The reaction was determined by investigating the soil available phosphorus, extractable lipid-phosphate, pH, moisture and fatty acid content.  A significant increase in the relative concentration of extractable lipid-phosphate, soil available phosphorus, and fatty acid content was identified, confirming the flux in the microbial biomass in the soil.  Contrary to these nutrients, there were no notable changes in the soil pH and moisture content. The findings of this study were able to highlight the future forensic potential of these techniques and demonstrate a need for further research.


title: Mock jurors’ perceptions of children testifying via a language interpreter

subject:
Interpreter-mediated interviews
Mock jurors’ perceptions
Youth testimony
Child sexual abuse

abstract: Language interpreters will increasingly be used in our globalized world. However, their impact on fact finders' perceptions is yet to be understood. The current research examined adults' perceptions of youth testifying via a language interpreter. (N =302) English-speaking participants in Study 1 and (N = 464) Spanish-speaking participants in Study 2 listened to two mock investigative interviews, one with a 7-year-old child and one with a 14-year-old adolescent. Half listened to interpreter-mediated interviews in a language in which the participant was not proficient (i.e., Spanish or English). Findings indicate that verbatim translations of the testimony resulted in differences in how mock jurors perceived young witnesses, the interviewer, and interview as a whole. For example, youth who testified via a language interpreter were rated as calmer and more comfortable with the interviewer than in typical interviews. The current study has implications for understanding jurors' perceptions of non-native language-speaking children and adolescents.


title: Development of thermodynamic cycles for sodium-cooled-fast reactors.

subject: Power-conversion Cycle Rankine Brayton Efficiency

abstract:
Currently, one engineering challenge is designing Generation IV (GEN-IV) Nuclear Power Plants (NPPs) with significantly higher thermal efficiencies compared to current NPPs, and to match, or at least to be close to, the thermal efficiencies reached by fossil-fired power plants, which are currently at the level of 40-62%.
As there are six GEN-IV nuclear-reactor concepts and the performance of these reactors-concepts depends on their design, it is reasonable to start with all GEN-IV reactor concepts and investigate the coolants and their characteristics in these concepts. For this objective, main thermophysical, corrosion, and neutronic properties of coolants of the GEN-IV reactors within the proposed temperature range of operation were investigated. Heat Transfer Coefficients (HTCs) for the coolants of the GEN-IV concepts were also calculated and compared to typical HTCs published in the open literature for coolant candidates.
Based on a comparison of properties and HTCs, a Sodium-cooled Fast Reactor (SFR) - one of the six concepts considered under the Generation IV International Forum (GIF), was selected because it is the most experienced reactor technology among all of the proposed GEN-IV reactor concepts. Moreover, with depleting uranium resources, there is an interest to design reactors that operate on a closed fuel cycle, and SFR is one of the potential options. A BN-600 reactor is a sodium-cooled fast-breeder reactor built at the Beloyarsk NPP in Russia, and it is in operation since 1980. On the secondary side it utilizes a subcritical-pressure Rankine-steam cycle with heat regeneration. The power-conversion system is presented, and calculations of thermal efficiency of this scheme have been performed and analyzed.
To achieve higher thermal efficiency of the plant, one of the possibilities is to increase thermal efficiency of the turbine cycle. Two main approaches for the SFR in terms of the power-conversion cycle were investigated: supercritical-pressure Rankine-“steam” cycle and supercritical-pressure CO2 Brayton-gas-turbine cycle. The feasibility of these options is discussed. The thermal efficiencies of ideal and non-ideal CO2 Brayton gas-turbine cycles were optimized by varying CO2 pressures and temperatures at the outlet of Na-CO2 heat exchanger.


title: Comparing exercise responses to high intensity interval training between adults with and without asthma

subject:
Exercise
Asthma
High Intensity Interval Training
Exercise Induced Bronchoconstriction

abstract: Exercise induced bronchoconstriction (EIBC) occurs in response to high ventilations during exercise, which cools and dries the airways, triggering an inflammatory cascade. High intensity interval training (HIIT) is associated with reductions in inflammation, improvements in cardiorespiratory outcomes, and mental health in healthy adults; however, the impact of HIIT in adults with EIBC is unclear. The purpose of this dissertation was to determine the impact of a 6-week HIIT intervention on physiological (e.g. inflammation, ventilation, and cardiorespiratory fitness) and psychological (i.e. anxiety) domains of health among adults with EIBC and healthy adults, and the impact of HIIT on clinical outcomes (i.e. asthma control) among adults with EIBC. METHODS: A quasi-experimental study design was used. A 6-week HIIT intervention was implemented in adults (18-44 years) with EIBC and healthy controls. Sessions were conducted three times per week and consisted of cycling at 10% PPO for 1 minute followed by 90% PPO for 1 minute, repeated 10 times. Primary measures at pre (T1) and post-intervention (T2) included: 1) maximal exercise test 2) passive drool saliva samples 3) anxiety sensitivity index-3 4) asthma control questionnaire-7 (EIBC group only). RESULTS: Participants in the EIBC group (n=20; T1: 32.9 ± 8.0; T2: 38.6 ± 8.2 ml/kg/min, p<0.01) and control group (n=12; T1: 38.6 ± 8.2; T2: 38.9 ± 12.3 ml/kg/min, p<0.01) improved VO2max. Adults with EIBC had lower levels of IL-1Ra at T2 when compared to healthy controls (EIBC T2: 0.2 ± 0.16pg/ug protein; Control T2: 0.8 ± 0.21pg/ug protein; p<0.01, hp2 = 0.3). Maximal ventilation in the EIBC group did not improve (EIBC T1: 97.8 ± 22.2; EIBC T2: 108.7 ± 29.5, p=0.7, Cohens d=0.4); however, the control group improved ventilation at the same absolute exercise workload (Control T1: 82.8 ± 20.1; Control T2: 101.8 ± 18.1, p=0.02). Reductions in anxiety sensitivity (EIBC T1: 17.9 ± 11.8; EIBC T2: 12.4 ± 13, p=0.002, Cohens d=0.4) and asthma control (EIBC T1: 0.8 ± 0.6; EIBC T2: 0.5 ± 0.4, p=0.02, Cohens d=0.5) from T1 to T2 occurred. CONCLUSION: A 6- week HIIT intervention leads to improvements in physiological, psychological, and clinical outcomes among adults with EIBC.


title: A graph-based real-time spatial sound framework

subject:
Spatial sound
Real-time
Acoustic modeling
Sound propagation
GPU

abstract: Given the importance of sound, and our ability to localize sound sources in three-dimensions in the real world, incorporating spatial sound in virtual environments can help increase realism, improve the sense of “presence”, or “immersion”, improve task performance, and improve navigation speed and accuracy. However, despite advancements in the real-time simulation of spatial sound, current solutions are computationally expensive and often rely on specialised hardware, and as a result, spatial sound cues are often overlooked in virtual environments and games notwithstanding their importance. Here, a novel spatial sound rendering framework that approximates spatial sound for virtual environments, yet conforms to physical sound propagation rules/laws, is introduced. The framework employs graphs in order to reduce computation time and each node in the graph is processed in parallel using the graphics processing unit (GPU) making this method suitable for real-time virtual immersive applications such as video games and virtual simulations. Results of a user study that was conducted with human participants (the intended users of any spatial sound method), to test the effectiveness of the spatial sound framework introduced here, indicates it does lead to improved player performance over traditional panning (binaural sound cues only) and ray-cast occlusion in a 3D first-person video game.


title: Characterization of two component systems of Acinetobacter baumannii.

subject:
Acinetobacter baumannii
Multidrug resistance
Two component systems
Gram-negative
Bacterial virulence

abstract: Acinetobacter baumannii is an important opportunistic pathogen of hospital acquired infection, particularly in intensive care units. The emergence and rapid spread of multidrug-resistant A. baumannii strains has become a major health threat worldwide which severely limits the treatment options for this pathogen. This work investigated global mechanisms of antibiotic resistance and virulence of the problematic pathogen A. baumannii, in particular those mediated by two component regulatory systems (TCSs), that typically consist of a membrane bound sensor kinase and a cognate response regulator. Bacterial TCSs play an important role in the regulation of adaptation to different environmental conditions. Five TCSs in A. baumannii have been characterized; however, there are a number of putative two component systems encoded in the genome of A. baumannii that await detailed characterization. Differential expressions of six different TCSs was observed in two clinical isolates of A. baumannii AB030 and AB031, and whole-genome sequencing of both clinical isolates was performed. Data obtained from the comparative whole-genome analysis revealed the presence of an insertion element in the orphan TCSs response regulator A1S_2006 in AB030, mutation in the promoter region and an 1189 DNA insertion element were present in AdeRS system in AB031. The whole-genome sequencing analysis of TCSs operons in AB030 and AB031 also identified sequence polymorphisms that could alter the activities of these TCSs in AB030 and AB031. Finally, we identified A1S_3229_30 an excellent candidate that may act as global regulator of antibiotic and virulence in A. baumannii. The sequence of A1S_3229_30 was highly conserved among the wild-type ATCC17978, AB030 and AB031, and showed 73% identity to the amgRS operon that encodes for the well characterized AmgRS system that confer resistance to aminoglycoside antibiotics and required for the virulence of the problematic pathogen P. aeruginosa.


title: The relationship between moderate physical activities and sleep quality and quantity among persons with dementia

subject:
Dementia
Physical activity
Sleep quantity
Sleep quality

abstract:
Aims and Significance: The prevalence of dementia is rapidly increasing worldwide due to an aging population. Sleep disorders are a common characteristic of dementia, and pose a significant threat to the quality of life of persons with the condition and their families. This study compared the sleep quantity and quality between active and inactive persons with dementia.
Methods: This study used a cross-sectional design. Telephone questionnaires were administered to 40 caregivers of a person with dementia. The caregivers answered the questions as proxies on behalf of their care recipient.
Results: Active persons with dementia experienced significantly better sleep quantity than their inactive counterparts (P=.000). Furthermore, the active group obtained significantly better overall sleep quality scores (P=.003). Specifically, sleep onset latency (P=.021) as well as daytime napping (P=.000) and drowsiness (P=.015) were significantly correlated with activity level.
Conclusion: The preliminary evidence from this study suggests that physical activity may be an important method of improving sleep in this population. This study will aid in the promotion of safe and effective ways for managing aspects of dementia that impact quality of life and encourage future research in this area.


title: The synthesis and in vitro evaluation of short interfering RNA containing triazole functionalized sphingolipid-based derivatives

subject:
Sphingolipids
siRNA
Gene-silencing
Cellular uptake
RNA interference

abstract:
RNA Interference (RNAi) is a natural cellular process that silences the expression of a target gene in a sequence-specific manner by mediating targeted mRNA degradation. One of the main challenges in RNAi research is developing an effective delivery system for siRNAs. Recently, fatty acid conjugated siRNAs have shown promising potential as safe and effective method to deliver oligonucleotides to extrahepatic cells. A class of fatty acids that we are interested in are sphingolipids, they are a class of lipids containing a backbone of sphingoid bases and aliphatic amino alcohols. Sphingolipids show potential as lipid-conjugated siRNAs as they are important structural and functional components of plasma membranes of eukaryotic cells.
Here, we design a library of siRNAs containing propyl-triazole modified sphingosine at various locations of the sense and antisense strand of the reporter gene firefly luciferase and evaluate its gene-silencing abilities in both the presence and absence of a transfection carrier.


title: Integration of deviation zone evaluation and point measurement planning in coordinate metrology

subject:
Integrated inspection system,
Deviation zone evaluation
Point measurement planning
Coordinate metrology

abstract: Reliable inspection of a manufactured part with coordinate Metrology demands excessive time to provide higher accuracy. The uncertainty of inspection highly depends on the number and location of points acquired during the measurement process. Isolation of the three main computational tasks in coordinate Metrology increases the overall inspection uncertainty drastically. Developing methodologies to integrate PMP and DZE is the main objective in this research. The developed solution for DZE solves Laplace equation around each measured point; while the sampling is guided by a Gaussian probability density function to model the manufacturing error on a fabricated part. The proposed dynamic sampling is studied on actual manufactured parts with a virtual approach to test the ability of the method.


title: Supporting Durham Catholic School District teachers in implementing movement integration: understanding and addressing the barriers through teacher coaching

subject:
Movement integration
Physical activity
Teacher coaching

abstract: Movement integration (MI) is short bursts of physical activity (PA) within classrooms during school hours. Despite cited benefits of MI, it is not well utilized by teachers. MI barriers include lack of time and confidence, safety concerns, and classroom disarray. Teacher coaching may help mitigate these issues. Teacher participants (n=12) at seven elementary schools were interviewed on their perceived barriers to MI. An MI specialist visited each teacher three times for five to ten minutes over three weeks to coach the teacher and class through MI activities. Results indicated a statistically significant increase in self-reported MI by teachers from pre to post-implementation (Z = -2.138, p = 0.0165, r = 0.6), improved teacher confidence (p = 0.048), and a strong, positive correlation (ꚍƅ = 0.627, p = 0.018) between confidence and competence. Findings indicate that teacher coaching may be an effective strategy to supporting teachers in overcoming barriers to MI.


title: A pragmatic testbed for distributed systems

contributor:
Zhu, Ying
Green, Mark

subject:
Distributed systems
Testbed
Peer-to-peer
Docker

abstract: Distributed systems have become ubiquitous and they continue their growth through a range of services. With advances in resource virtualization technology such as Virtual Machines and software containers, developers no longer require high-end servers to test and develop distributed software. Even in commercial production, virtualization has streamlined the process of rapid deployment and service management. This thesis introduces a distributed systems testbed that utilizes virtualization to enable distributed systems development on commodity computers. The testbed can be used to develop new services, implement theoretical distributed systems concepts for understanding, and experiment with virtual network topologies. We show its versatility through three case studies that utilize the testbed for designing a service based solution, implementing a theoretical algorithm, and developing our own methodology to find high-risk edges. The results of using the testbed for these use cases have proven the effectiveness and versatility of this testbed across a range of scenarios.


title: Modelling, inspection, and post-processing of layer-based additive manufacturing surfaces to maintain product quality

subject:
Surface quality
Additive manufacturing
FDM
Surface topography
Acetone vapour bath smoothing

abstract:
Today’s Additive Manufacturing (AM) is mostly layer-based. Despite AM’s great capabilities in fabrication of complex geometries, product’s surface roughness is a limiting factor in many industrial applications. Therefore, application of AM parts in industrial services highly relies on appropriate modeling, inspection, and post-processing of the fabricated surfaces. A thorough investigation of surface roughness to improve surface quality of AM products is the focus of this thesis by developing methodologies to complete the three tasks of modelling, inspection, and post-processing of AM surfaces.
A theoretical formulation to model surface roughness of layer based manufactured parts is developed by defining centerline using a Total Least Square (TLS) approach and the model is validated experimentally. The developed model is also used for surface topography of AM parts as a new metrology approach. Optical scanning data point cloud of Fused Deposition Modeling (FDM) parts are used to conduct inspection based on the developed methodology. 3D topography of the surfaces are reconstructed when a good agreement with the corresponding 2D profilometer inspection is observed. Acetone vapour bath smoothing is used for post-processing of FDM parts. The number of smoothing cycles, and the duration of each cycle are considered as the main smoothing parameters. Effect of geometric complexity and smoothing parameters are studied and the best smoothing settings are proposed for a desired level of smoothing requirement. The developed experimental models allow engineers to plan the smoothing process based on the build orientation and geometric complexity of the product.


title: Experimental investigation and evaluation of hybrid ammonia fuel options for power generators

subject: Generators Ammonia Gasoline Hydrogen Fuel

abstract: This research thesis aims to make use of ammonia as a possible fuel source for power generators by performing an experimental study on a gasoline generator with an ammonia based gasoline fuel blend. Then, the combustion is modelled by using different types of fuel sources which are; hydrogen, gasoline, diesel, ethanol, methanol, propane, butane and natural gas to see the effects of ammonia on these fuels. In the experimental studies the exhaust temperatures, power output, CO2 emissions, overall energy and exergy efficiencies of the generator are measured in between 369.9 Co to 480.1 Co, 3689.2 W to 3572.8 W and 2.535 g/s to 2.4916 g/s, 35.7 % to 28.74% and 44.85 % to 36.4 %, respectively with the increase of ammonia percentage in the fuel blend. The reduction in the performance measures are as expected but the reduction in CO2 emissions will be worth using ammonia with a combustion promoter.


title: Design, development and experimental validation of a lab-scale system for rapid rotational molding of functionally graded integral-skin cellular polyethylene composites

subject:
Rapid Rotational Foam Molding
Functionally Graded Cellular Composites
Physical bowing agent
Chemical blowing agent
Polyethylene

abstract: An existing lab-scale experimental setup system, originally developed for a patented Rapid Rotational Foam Molding (RRFM) process, was re-designed, built, and its functionality was successfully experimentally verified. The primary objective of the research work presented in this thesis was to provide the physical means to introduce a physical blowing agent (PBA) into RRFM processing operations in order to enable seamless processing of functionally graded polyethylene foamed composites. The quality of the produced specimen were assessed in terms of: foam density, volume expansion ratio, cell density, and cell size. The experimentally obtained rotationally molded foam composites desirably exhibited gradual change in compositional quality and morphology from one region to another, which was correlated with the thermal gradient that exist within the rotational mold during the part cooling process. The newly designed functionally graded cellular composites can have wide applications in automotive, aerospace and marine industries.


title: Connecting neoliberal ideology and incel ideology

subject: Incels Neoliberalism Ideologies Misogyny

abstract: Incels are an online transgressive subculture holding misogynistic views of women, including the belief that women unfairly refuse them sex. While there have been few heinous physical attacks by individuals self-identifying as incels, their ideologies also pose a significant threat to the struggle to end misogyny. This thesis explores and identifies connections between neoliberalism and incel ideologies. A netnographic method was employed to collect qualitative data from a range of social media communities. Six major themes emerged from these data: resentment, hopelessness, coping with ontological insecurity, inauthentic women, significance of sexual relations, and the sexualization and objectification of women. These themes are connected to contemporary features of neoliberal ideology, and finds that incels either acknowledge but reject these neoliberal expectations or incorporate them into their own belief systems.

abstract: University of Ontario Institute of Technology


title: SegmentPerturb: effective black-box hidden voice attack on commercial ASR systems via selective deletion

subject:
Automatic Speech Recognition System
Hidden Voice Command

abstract: Voice control systems continue becoming more pervasive as they are deployed in mobile phones, smart home devices, automobiles, etc. Commonly, voice control systems have high privileges on the device, such as making a call or placing an order. However, at the same time, they are vulnerable to voice attacks, which may lead to serious consequences. In this thesis, SegmentPerturb was proposed to craft hidden voice commands via inquiring the target models. The basic idea of SegmentPerturb is that the original command audio was separated into multiple segments and a certain degree of perturbation was applied to each segment by probing the target speech recognition system. Experiments were conducted on four popular commercial speech recognition APIs plus one smart home device to show the practicability of SegmentPerturb. Results suggest that SegmentPerturb can generate voice commands which can be recognized by the machine but are hard to understand by a human.


title: Exploring global dynamics in a low order model of parallel shear flow

subject:
Homoclinic orbit
LPNS bifurcation
Unstable manifold
Turbulence

abstract:
The study of the onset of turbulence in the flow of fluids, which are governed by the
Navier-Stokes equations, has produced some famous instabilities e.g. Kelvin Helmholtz
instability. An important, and as of yet mysterious, flow is Plane Couette flow in which
turbulence is observable. Another observable phenomenon in Plane Couette flow is a
“bursting” process whereby along with the linear laminar profile, non-laminar coherent
structures appear and dissipate regularly. Yet, surprisingly V.A. Romanov has proven
that the linear laminar profile of Plane Couette flow is linearly stable for all Reynolds
number. In order to reconcile these seemingly contradictory facts a search began for
numerical periodic solutions to Plane Couette flow. Nagata produced the first such
solution and since then many others have been found as well. In order to explain
the “bursting” process Fabian Waleffe introduced a low order model of Plane Couette
flow that exhibits the phenomenon. We study the bifurcation diagram of a periodic
solution of the Waleffe model found by the method of Nagata. Therein we find a codimension
2 bifurcation. The type of bifurcation, namely LPNS, ensures that we can
find homoclinic and heteroclinic connections of limit cycles in the parameter space
surrounding the it. We use a matrix-free manifold computation method to find a
homoclinic orbit of limit cycles. Finally we will discuss a method to continue the
homoclinic orbit.


title: Combustion and emission characteristics of ammonia blended fuels in a spark-ignited engine

subject:
Ammonia
Combustion
Emissions
Dual fuel
Alternative fuel

abstract: Climate change and fossil fuel depletion has brought attention to the need for alternative fuels. Ammonia shows great potential as an alternative fuel because it is carbon-free and can be produced renewably. In this study the combustion and emission characteristics of ammonia blended fuels are investigated for spark ignited engines. Gasoline and heptane are explored as combustion promoters for ammonia. Experiments have been conducted on a single cylinder research engine fitted with an electronic dual fuel injection system. A parametric analysis has been conducted to investigate the effects of fuel blend ratio, engine speed, air fuel ratio, and spark timing. Blends with up to 70% ammonia have displayed good premixed combustion characteristics while reducing carbon emissions. Ammonia blends have been found to perform best at higher spark advances than baseline cases due lower flame speeds. The results show that ammonia blends are a promising alternative fuel option.


title: A Vision-Based System For Non-Intrusive Posture Correction Notifications

subject:
computer vision
posture
HCI

abstract: Sedentary lifestyle and the prolonged sitting associated with it may have negative health consequences and poor sitting posture only exacerbates that. In this thesis I propose a software application for monitoring a computer user’s posture using a webcam, and notifying them in an unintrusive way when poor posture is detected.


title: Self-healing solutions for LTE evolved packet core

subject:
Self-healing
Network survivability
LTE EPC
Service continuity

abstract:
The 3GPP Long Term Evolution (LTE) is considered as a dominant future cellular wireless
technology in terms of performance and user experience. With technological advancement of the
wireless networks, dependencies and business impact of the mobile network services have
increased phenomenally. It is, therefore, crucial to address the issues regarding network
infrastructure or service failure. In this thesis, a self-healing solution is presented for the LTE
Evolved Packet Core (EPC) with a view to maintaining service continuity in the event of core
network elements - the MME and S-GW failures. The core network element failures have
significant impact on a larger number of subscribers in comparison to the access network element
failures. In the proposed self-healing scheme, the restoration mechanisms and associate failover
recovery procedures with regards to service survivability are described in details from the LTE
network and protocol perspective.
This thesis studies two different self-healing approaches - the centralized active-backup and
distributed active-active and conducts simulation for each approach in various failure scenarios.
The performances of each of these scenarios are evaluated in terms of service restoration time,
throughput, EPS (Evolved Packet System) bearer delay etc. The results show that the proposed
self-healing system can ensure service continuity at a certain level if resources are properly
provisioned. And in terms of restoration delay, in general, the active-backup configuration
performs better than the active-active configuration.
The thesis presents analytical and simulation methods to estimate signaling message overhead at
the LTE EPC that arises due to the recovery process. It also analyzes the bandwidth requirements
of the signaling traffic that is incurred by the other operational procedures of the self-healing
scheme and their ramification to the LTE core network.


title: H-Delta: design and applications of a novel 5 degree of freedom parallel robot

subject: Parallel Robotics UAV Manipulator

abstract:
This thesis presents a new parallel 5 DOF robot called the H-Delta. The H-
Delta adds 2 degrees of freedom (DOF) to the traditional Delta robot in a novel
way, adding functionality and versatility. Importantly, the rotational DOF are
decoupled, independent of the translational movement.
This thesis begins by covering the necessary background the H-Delta is built
upon, and then describes the structure of the H-delta and how it improves upon
the state-of-the-art. The kinematic analysis of the H-Delta covers the inverse
kinematics, Jacobian matrix derivation, stiffness, and dexterity. To provide a
reference to an existing structure the H-Delta is compared to the benchmark
Stewart Platform.
A Dynamic analysis is performed by formulating the dynamic equations of
the H-Delta using the Lagrangian method. The results of the dynamic calcu-
lations are verified with a dynamic simulation which also acts as a test bed to
develop control systems.
A multi-objective optimization of the H-Delta is presented and using the in-
formation accrued to this point an initial prototype is designed and constructed
to verify the H-Delta structure.
With the knowledge of the strengths of the H-Delta gained from the analysis
and prototype, select applications are presented where the H-Delta best lends
its strengths to the application.
The H-Delta is mounted on a UAV to survey and interact with its surroun-
dings. The prototype can use an on-board camera to track the position of an
objective on the ground and center the gripper over it. When the UAV gets close
enough, the H-Delta reaches out and automatically retrieves the object. When
flying around, the H-Delta stabilizes the movement of the end effector, reducing
acceleration. The prototype movement is measured and the results show that
the end effector is accurate to within 3mm and the rotation is accurate within
0.5 degrees.


title: Changing prostitution discourse in Canadian common law from 2010 to 2018

subject:
Sex work
Sex work legislation
Discourse analysis
Anti-carceral feminism
Governmentality

abstract: Since the first iteration of prostitution legislation in 1759, the language and discourses used to refer to ‘prostitution’ has undergone many changes. The constitutional challenge of Bedford v. Canada (2010 ONSC 4264) resulted in legislative amendments of prostitution laws (Bill C-36). Bill C-36, implemented in 2014, resulted in several significant changes, including the eradication of the word ‘prostitution’ from the Criminal Code, and the criminalization of buying, but not selling, sexual services. Given Bill C-36, this research inquires: How has prostitution discourse changed in Canadian common law from 2010 to 2018? A discourse analysis of 58 court decisions compared the language used before and after 2014; this revealed courts’ frameworks for understanding sex work have not changed significantly despite the Bedford ruling, since exploitation remains the major discursive underpinning. The theoretical framework integrates anti-carceral feminist theory and governmentality, to render visible the marginalization, discrimination and stigmatization of the paternalistic punitive system on sex workers.


title: Nonlinear vibration analysis of viscoelastic plates with fractional damping

subject:
Nonlinear vibration
Viscoelastic plate
Fractional damping
Variational iteration method
Multiple time-scale method

abstract: Fractional calculus has the history as long as the classical calculus, but up to recent years, less attention has been paid to this method due to its complexity and difficulties in dealing with fractional derivatives and fractional integrals. In the present study, the nonlinear vibration analysis of a rectangular composite plate with fractional viscoelastic properties has been analytically investigated. The plate is modeled based on the von Kármán plate theory, and the Caputo’s fractional derivative has been utilized to mathematically model the viscoelastic behavior of the plate with higher accuracy. Galerkin procedure has been implemented to derive the time-dependent ordinary differential equations of motion. The first two orthogonal mode shapes are considered, and variational iteration method is applied to analyze the nonlinear free vibration of the system. The method of multiple time-scales is utilized to investigate the nonlinear forced vibration of the plate when subjected to an external harmonic force. Primary resonances of the system have been studied and analytical expressions for the frequency-amplitude relationships of each mode are derived. Parametric studies have been performed to examine the effect of various parameters, specifically the fractional derivative order as a key factor, on the damped free vibration response and the forced vibration frequency response.


title: Design of active trailer steering systems for long combination vehicles using robust control techniques

contributor:
He, Yuping
Ren, Jing

subject:
Long combination vehicles
Robust control
Active trailer steering
Kalman filter
Mu synthesis

abstract: The exponential growth in freightage and the ever-increasing traffic congestion has aided Long Combination Vehicles (LCVs) to emerge as an economical and pragmatic solution for freight transport compared to single unit vehicles. Despite their numerous merits, LCVs face certain stability challenges at high speeds and exhibit inferior maneuverability at low speeds. LCVs are especially susceptible to unstable motion modes, such as rollover, jack-knifing and trailer sway, which has escalated strong concerns regarding their safety. Therefore, it is imperative to develop safety systems with a focus on improving stability, and ensuring safety of LCVs. Active safety systems such as Active Trailer Steering (ATS), have been widely explored to overcome these stability challenges. So far, the design of ATS systems have utilised the Linear Quadratic Regulator (LQR) control technique. Although the LQR technique provides satisfactory results, it fails to control the system in presence of external disturbances such as sensor noise, parametric uncertainties, and un-modelled dynamics. This encourages the need of a robust control strategy. This research focuses on developing an ATS system for a B-train double using robust control techniques. The robust Linear Quadratic Gaussian (LQG) and the 𝜇 synthesis control techniques are employed for designing the ATS control system. The control techniques are analysed under a variety of tests by using numerical simulations. TruckSim and MATLAB/Simulink software packages are used for numerical simulations. The results suggest that the LQG control technique effectively controls the system in the presence of noise, whereas the 𝜇 synthesis control technique is able to achieve desired system performance in the presence of noise, and parametric uncertainties.


title: Low energy photon mimic of the tritium beta decay energy spectrum

subject:
Tritium
MCNP
Low energy electrons
Biophysics
Characteristic x-rays

abstract:
Tritium is a radioactive hydrogen isotope that is typically produced via neutron interaction with heavy water (D2O), producing tritiated water (DTO). As a result of this, tritium accounts for roughly a third of all occupational exposures at a CANDU type nuclear power plant. This identifies a need to study the biological effects associated with tritium (and low energy electrons in general). However, there are complications regarding the dosimetry of tritium, as well as difficulties in handling and using tritium for the purposes of biophysics experiments. To avoid these difficulties, an experiment has been proposed using photons to mimic the beta decay energy spectrum of tritium. This would allow simulation of the radiation properties of tritium, so that a surrogate photon source can be used for biophysics experiments.
Through experimental and computational means, this work has explored the use of characteristic x-rays of various materials to modify the output spectrum of an x-ray source, such that it mimics the tritium beta decay spectrum. Additionally, the resultant primary electron spectrum generated in water from an x-ray source was simulated. The results from this research have indicated that the use of characteristic x-rays is not a viable method for simulating a tritium source. Also, the primary electron spectrum generated in water shows some promise for simulating tritium exposure, however further work must be done to investigate the slowing down electron spectrum.


title: Multimodal series elastic actuator for human-machine interaction with applications in robot-aided rehabilitation

contributor:
Rossa, Carlos
Nokleby, Scott

subject:
Series elastic actuator
Human-machine interaction
Robot-aided rehabilitation
Robotics

abstract: Series elastic actuators (SEAs) are becoming an elemental building block in collaborative robotic systems. They introduce an elastic element between the mechanical drive and the end-effector, making otherwise rigid structures compliant when in contact with humans. Topologically, SEAs are more amenable to accurate force control than classical actuation techniques, as the elastic element may be used to provide a direct force estimate. The compliant nature of SEAs provides the potential to be applied in robot-aided rehabilitation. This thesis proposes the design of a novel SEA to be used in robot-aided musculoskeletal rehabilitation. An active disturbance rejection controller is derived and experimentally validated and multiobjective optimization is executed to tune the controller for best performance in human-machine interaction. This thesis also evaluates the constrained workspaces for individuals experiencing upper-limb musculoskeletal disorders. This evaluation can be used as a tool to determine the kinematic structure of devices centred around the novel SEA.