title: Robotic and haptic assistance for kidney access during percutaneous nephrolithotomy

contributor:
Rossa, Carlos
Nokleby, Scott (Nominal)

subject:
Robotic surgery
Percutaneous nephrolithotomy
Path planning
Tool bending
Haptic feedback

abstract: Percutaneous nephrolithotomy (PCNL) is a minimally invasive procedure for removing kidney stones. Gaining kidney access is the most challenging task in this procedure and the cause of many complications. This thesis presents semi-autonomous solutions for improving PCNL procedure outcomes. First, a cyber-physical PCNL simulator incorporating haptic feedback and simplifying surgeon mental workload via teleoperation of a nephroscope, the surgeon controls the tooltip position while a robotic agent controls its orientation. This thesis then explores how subtask automation can further improve the procedure. A multi-objective path planning algorithm is implemented to generate multiple suitable paths for kidney access, from which an expert surgeon selects one for execution. The robotic agent then steers the tool along the path autonomously. A further advancement adds a tool/tissue interaction model which determines tool bending; thereby providing accurate trajectory tracking. The concepts are validated experimentally in ex-vivo and phantom tissues.


title: Design and development of an extended range electric bywire/wireless hybrid vehicle with a near wheel motor drivetrain

subject:
Automobile propulsion
Electrical hybrid vehicle
By-wireless brakes
Direct-drive prototype
Drive-by-wire prototype
Extended range electric vehicle

abstract:
With automobile propulsion energy sources turning away from petroleum, the evolution
of technology naturally lends itself to electrical hybrid vehicle architectures relying on
alternatives as a primary electrical energy source. This thesis presents a design solution of
a direct-drive and drive-by-wire prototype of a hybrid extended range electric vehicle
(EREV) based on a dune buggy test bed. The developed setup eliminates nearly all
mechanical inefficiencies in the rear wheel drive transaxle drivetrain. All controls have
been purposely designed as a duplicate set to allow for full independent control of both
rear wheels in a truly independent architecture. Along with the controls supporting the
design, the motors have been mounted in a near wheel fashion to adequately replace a
true hub motor setup. In addition, by-wire throttle and by-wireless brakes in a servomechanical
fashion have been developed. The by-wireless braking system is used to
control regenerative braking for the rear of the vehicle only allowing for the front brakes
to be the primary means of braking as well as a mechanical safety redundancy. This
design allows for developments in the areas of truly independent electronic differential
systems and studies of the effect of near wheel motor setup. The efficiencies gained by
the design solutions implemented in this thesis project have shown their ability to be used
in a functioning motor vehicle. Direct gains in mechanical efficiency as well as the
removal of a non eco-friendly gasoline powertrain have been attained. In addition, an
electric architecture has been developed for further research in future studies such as
vehicle stability control, traction control and all-wheel-drive architectures.

abstract: University of Ontario Institute of Technology


title: The anti-estrogenic and liver metabolic effects of DHAA in rainbow trout (oncorhynchus mykiss)

subject:
Pulp mill effluent
VTG
EROD
Anti-estrogenic
Liver metabolic enzymes

abstract:
Recent studies have shown that dehydroabietic acid (DHAA), a resin acid
present in pulp and paper mills, may have anti-estrogenic effects in fish. A
chronic-exposure toxicity experiment using immature rainbow trout
(Oncorhynchus mykiss) was conducted in order to assess the endocrine
disrupting and liver metabolic effects of the wood extractives DHAA and β-
sitosterol (BS) regularly present in pulp and paper mills and the model estrogen
17β-estradiol (E2). It was found that exposure to 5 ppm of E2 significantly
increased hepatosomatic index (HSI), vitellogenin (VTG) and plasma sorbitol
dehydrogenase (SDH). This effect was reduced by mixing E2 with DHAA,
indicating that DHAA does not cause its anti-estrogenic effects indirectly due to
liver damage. Exposure to 5 ppm of DHAA caused a significant increase in liver
citrate synthase (CS), and liver ethoxyresorufin-O-deethylase (EROD) activity
after 7 days, however, the fish recovered by 28 days. This study also determined
the effect of 14 different pulp and paper mill effluent extracts on liver enzyme
metabolism through alterations in the activity of liver lactate dehydrogenase
activity (LDH) and CS. This activity varied greatly between mills but most
showed an induction of CS after 28 days exposure through i.p. injection. The
results of the study indicate that DHAA may alter energy metabolism as well as
cause anti-estrogenic effects in female juvenile rainbow trout.


title: Virtual drilling haptics perception from auditory cues employing low-end haptic devices

contributor:
Kapralos, Bill
Quevedo, Alvaro Joffre Uribe

subject:
Haptic
Audio
Human-Computer Interaction
Fidelity
Virtual simulation, Drilling

abstract:
Simulation-based training is being widely adopted in medical education because it allows exposing trainees to safe and controlled simulated scenarios otherwise impossible to reproduce in real life. Current advances in immersive technologies including those related to Virtual Reality (VR), and Augmented Reality (AR), are providing innovative tools to design immersive virtual simulation solutions that are available to a wide range of users through consumer-level hardware. As a result, the field of simulation is currently seeing a great effort and emphasis on the use of VR/AR, to motivate and engage the trainee in an ethically safe and cost-effective manner. Although the use of virtual simulation in medical education is rapidly becoming more widespread, most applications are still focused on cognitive skill development. Due to various technical limitations and cost issues, technical skill development
(e.g., surgical drilling skills), that requires the simulation of the sense of touch in the virtual domain require high-end and expensive haptic devices and are therefore, often overlooked. Current high-end haptic devices are restricted to larger institutions that can afford the complex hardware, thus limiting a larger user install base. On the other hand, low-end haptic devices with limited functionality regarding degrees of freedom, force feedback, and resolution, are available. However, further studies are required to understand their suitability for medical training and as an alternative to their high-end counterparts. The goal of this work is to determine whether sound can be used to increase the perception of haptic fidelity inherent in consumer-level haptic devices to allow the use of such devices (coupled with the appropriate auditory cues) in applications that require higher fidelity at a fraction of the associated cost. Here I present an experiment in which participants were asked to perform a virtual drilling task (drilling wood) using two consumer-level haptic devices (Novint Falcon, and 3D
Systems Touch 3D Stylus) in the presence of contextual sound (prerecorded wood drilling sound) and non-contextual sound (no sound, classical music, and white noise). Although the results of this study do not show any statistically significant difference in task performance the experiment is a necessary step in understanding the role of sound on haptic perception.


title: Investigation of new phase change material based thermal management systems for Li-ion batteries

contributor:
Dincer, Ibrahim
Rosen, Marc A.

subject:
Electric vehicle
Li-ion battery
Thermal management
Phase change material
Carbon nanotube

abstract:
In this thesis, a battery pack consisting of three A123 20Ah cells connected in series is tested with various cooling methods at different discharge rates. Four different coolant inlet temperatures are selected for the investigation. The results from the battery pack tests at no cooling show that the surface temperature of the battery increases with an increase in discharge rate. The highest average temperature of the battery pack is 56.5°C, corresponding to no cooling case at a high discharge rate. With cold plates, the battery temperature remains in the specified temperature range at all discharge rates, when the coolant temperature is 30°C. The results show that the thermal management system developed in the present study using 6 mm thick phase change composite plates can manage the battery temperature in the required range. n-Octadecane and polyurethane foam are used to make 3 mm and 6 mm thick plates. The battery pack is tested with the developed phase change material based plates. Carbon nanotubes are used to improve the thermal conductivity of the phase change material, along with polyurethane foam. The results show that 3 mm thick plates made from pure phase change material, 3% (wt.) Carbon nanotubes and polyurethane foam can maintain the battery temperature within the required range at all discharge rates.
The internal resistance of the cylindrical and prismatic Li-ion batteries is measured at different states of charge and operating temperatures. The obtained results are used to develop a model for the battery pack in MATLAB Simulink. The good agreement attained between the simulation results and the experimental data shows that the developed model can be used to predict the behaviour of Li-ion batteries with reasonable accuracy. An economic analysis shows that the material cost of the developed PCM-based passive thermal management system for a complete
battery pack on a lab scale will be approximately $4500. The material cost of the developed thermal management system is reduced by approximately 44% when carbon nanotubes are used with the pure PCM and can be further reduced with production on an industrial scale. A preliminary optimisation of the developed system is performed using a genetic algorithm to maximise the driving range of the vehicle.


title: Powertrain technology and cost assessment of battery electric vehicles

subject:
Electric vehicle
EV technology
Sustainable alternative transportation
Battery chemistries
Cost assessment
GHG reduction

abstract:
This thesis takes EV from the late 90’s as a baseline, assess the capability of today’s EV technology, and establishes its near-term and long-term prospects. Simulations are performed to evaluate EVs with different combinations of new electric machines and battery chemistries.
Cost assessment is also presented to address the major challenge of EV commercialization. This assessment is based on two popular vehicle classes: subcompact and mid-size. Fuel, electricity and battery costs are taken into consideration for this study. Despite remaining challenges and concerns, this study shows that with production level increases and battery price-drops, full function EVs could dominate the market in the longer term. The modeling shows that from a technical and performance standpoint both range and recharge times already fall into a window of practicality, with few if any compromises relative to conventional vehicles. Electric vehicles are the most sustainable alternative personal transportation technology available to-date. With continuing breakthroughs, minimal change to the power grid, and optimal GHG reductions, emerging electric vehicle performance is unexpectedly high.


title: Design and Optimization of Intelligent PI Controllers (Fuzzy and Neuro-Fuzzy) for HVDC Transmission System

contributor:
Sood, Vijay K.
Ren, Jing

subject:
HVDC converter
Fuzzy logic controller
Membership function
Neuro-fuzzy controller
EMTP-RV

abstract:
This thesis deals with enhancing the performance of Fuzzy Logic (FL) based PI controllers for High Voltage Direct Current Transmission Systems (HVDC) by optimizing the key parameters i.e. membership functions (MFs) and fuzzy rule base in the controllers design.
In the first part of the thesis, an adaptive Fuzzy PI controller is designed and the effect of various MF shapes, widths and distribution on the performance of a FL controlled HVDC system under different system conditions is studied with the aim of selecting a MF which minimizes the total control error. Simulated results show that the shape, width and distribution of a MF influences the performance of the FL controller and concludes that nonlinear MFs (i.e. Gaussian) offer a more better choice than linear (i.e. Triangular) MFs as the former provides a smoother transition at the switching points and thus propose a better controller.
In the second part of the thesis, a Neuro-Fuzzy (NF) controller to update the fuzzy rule base with changing system conditions is proposed, which in turn adjusts the PI gains of a conventional PI controller. Results from simulations illustrate the potential of the proposed control scheme as the NF controller successfully adapts to different system conditions and is able to minimize the total current error.


title: Experimental and numerical studies of flows over forward facing steps in pressure gradients

subject:
Adverse pressure gradient
Forward facing step
PIV
POD
Two-point correlation

abstract: This thesis reports experimental and numerical studies of the effects of adverse pressure gradients (APG) and Reynolds numbers on flows over forward facing steps (FFS). For the experimental work, particle image velocimetry was used to conduct velocity measurements at several locations downstream of the FFS. Proper orthogonal decomposition and two-point correlation were applied to the experimental data to study the large scale structures. For the numerical analysis, turbulence models in ANSYS Fluent were used to study the reattachment length XL for blockage ratios from 5.8% to 29.5% and step inclination angles from 22.5˚ to 135˚.  The experimental results show that XL increases with the increase in Reynolds number without APG, but remains nearly constant for increasing APG. The CFD results show that as the step angle is increased, XL decreased. Furthermore, increasing the blockage at constant Reynolds number, the XL values decrease.


title: Characterizing Plankton communities in Lake Ontario coastal wetlands along an urban land-use gradient

subject:
Plankton communities
Water quality
Land use
Lake Ontario coastal wetlands
Biomanipulation

abstract: This thesis presents the results of a study on the effect of habitat condition and water quality on plankton communities across an urban land-use gradient in the Lake Ontario coastal wetlands: Frenchman’s Bay, Lynde Marsh, McLaughlin Bay, and Bowmanville Marsh over two years (2018-2019). One of the study wetlands (McLaughlin Bay) was assessed over three years (2017-2019) for its suitability as a candidate wetland for biomanipulation restoration. I found water quality was generally not degraded along the urban gradient as expected. Nutrient rich waters and high chloride concentrations were determined to be important drivers of decreased diversity and higher algal biomass dominated by cyanobacteria. In my assessment of McLaughlin Bay, I found that due to the nutrient- and chloride-rich conditions, the plankton community was dominated by inedible algal communities, and small zooplankton taxa. These results do not support applying biomanipulation as a restoration approach in McLaughlin Bay at this time.


title: Annual incidence of traumatic brain injury among Ontario adults with and without intellectual and developmental disabilities and 30-day readmissions

subject:
Traumatic brain injury
Developmental disability
Epidemiology
Readmissions

abstract:
This thesis examines Ontario adults with and without intellectual and developmental disabilities (IDD), to identify traumatic brain injury (TBI) incidence and the impact of TBI history on 30-day readmissions.
Objectives: 1) compare TBI incidence between adults with and without IDD over time and by demographic characteristics; 2) compare odds of 30-day readmissions between adults with IDD, history of TBI, or both in 2016/17.
Manuscript 1: Using a historical cohort design, TBI incidence was greater among adults with IDD versus without in all 15 study years.
Manuscript 2: This historical cohort study determined that having IDD or IDD and a history of TBI increased the odds of 30-day readmissions versus history of TBI only.
Conclusion: Results of this thesis suggest that among adults with IDD, risk of TBI is higher versus those without IDD, and 30-day readmissions are similarly increased among those with IDD with or without a history of TBI.


title: Multi-antenna relay network beamforming design for multiuser peer-to-peer communications.

subject:
Multi-user peer-to-peer relay network
Lagrange dual domain
Semi-definite relaxation
(SDR)
Signal-to-noise ratio

abstract:
In this work, we consider a multi-user peer-to-peer relay network with multiple multiantenna
relays which employ amplify-and-forward relaying protocol. Assuming distributed
relay beamforming strategy, we investigate the design of each relay processing
matrix to minimize the per-antenna relay power usage for given users’ Signal-to-Noise
Ratio (SNR) targets. As the problem is NP-hard, we develop an approximate solution
through the Lagrange dual domain. Through a sequence of transformations, we
obtain a semi-closed form solution which can be determined by solving an efficient
semi-definite programming problem. We also consider the semi-definite relaxation
(SDR) approach. Compared with this SDR approach, the proposed solution has significantly
lower computational complexity. The benefit of such a solution is apparent
when the optimal solution can be obtained by both approaches. When the solution is
suboptimal, simulations show that the SDR approach has better performance. Thus,
we propose a combined method of the two approaches to trade-off performance and
complexity. Simulations showed the effectiveness of such a combined method. In the
next step, we change the previous objective and constraints to turn the optimization
problem into a total power minimization problem for the relay network. We
use an approximation by solving this problem in the Lagrange dual domain, and we
finally obtain a semi-closed form solution through the dual approach. The use of the
SDR approach to solve this problem is also discussed. After analysis, we find the
two methods have an advantage over different aspects, thus we propose a combined
method for this problem. We eventually compare the two combined methods to see
the performance difference in the per-antenna power case and the total relay power
case, and discuss reasons for this difference.


title: Time-efficient offloading and execution of machine learning tasks between embedded systems and fog nodes

subject:
Machine learning
Embedded systems
Offloading
Fog networks

abstract: As embedded systems become more prominent in society, it is important that the technologies that run on them must be used efficiently. One such technology is the Neural Network (NN). NN's, combined with the Internet of Things (IoT), can utilize the massive amounts of data produced to optimize, control, and automate embedded systems, giving them more functionality than ever before. However, the status quo of offloading all NN functionality onto external devices has many flaws. It forces the embedded system to completely rely on networks which may have high latency or connection issues. Networks may also expose them to security risks. To reduce the reliance of IoT devices on networks, we examined several solutions such as delegating some NN's to run solely on the IoT device or splitting the NN and distributing the subnetworks into different devices. It was found that, for shallow NN's, the IoT device itself could run the NN at a rate faster than offloading it to an external device, but the IoT device needed to offload its inputs once the NN's started to increase in layers and complexity. When splitting the NN, it was found that the number of messages sent between devices could be reduced by up to 97% while only reducing the accuracy of the NN by 3%.


title: The ergonomic evaluation of laptop use in university students: the development and test-retest reliability of the student laptop use and musculoskeletal posture questionnaire

subject:
Test-retest reliability
Ergonomic exposure
Questionnaire
Laptop use

abstract: Laptop computer use is associated with health problems such as musculoskeletal pain. Few methods exist to measure ergonomic exposures to laptop use. My thesis aimed to develop and evaluate the test-retest reliability of the Student Laptop Use and Musculoskeletal Posture (SLUMP) questionnaire in undergraduate students. The questionnaire measures laptop use duration and postures for recreational, academic and employment purposes, breaks, and use of external accessories. A pilot study demonstrated that the questionnaire was acceptable for students. 179 undergraduate students were invited to complete the questionnaire twice within a seven-day interval. Weighted kappa statistics were computed to describe the reliability. 86.0% of eligible students agreed to participate and 59.1% completed both questionnaires. The reliability of 72.5% of questions was Kw ≥0.60 and 29.4% of questions was Kw ≥0.80. The SLUMP questionnaire offers a promising method to measure ergonomic exposures to laptops in university students but requires revisions to improve its reliability.


title: Manipulator’s configuration design, excavation path generation, and underground object detection for an autonomous electric excavator

contributor:
Seo, Jaho
Lin, Xianke

subject:
Autonomous excavator
Robotics
Path generation
Pipe detection
Energy saving

abstract: Construction is an industrial sector that requires high labor costs and is exposed to harsh and hazardous environmental conditions. As a solution to these problems, an autonomous excavator is expected in high demand. To increase the energy efficiency in autonomous excavators, and increase the safety of operation for them, the objectives of this research are threefolds. The first one is to design and fabricate an excavator with parallel electrical linear actuators. The second one is to develop and test the PSO-based and PFM-Based path generation algorithms for this excavator in order to save energy, maintain the digging efficiency, and avoid colliding with underground objects. In addition, the third one is to detect the metallic pipes and electricity carrying wires underground, using two inexpensive magnetometer sensors attached to the bucket of the autonomous excavator, and computer vision for verification of digging and motion accuracy.


title: The perceived barriers to exercise and physical activity for individuals with metastatic cancer undergoing chemotherapy: a qualitative exploration

contributor:
Lemone, Manon
Weaver, Robert

subject:
Cancer
Metastatic cancer
Exercise
Physical activity
Barriers

abstract: Over the recent years Exercise and Physical Activity (PA) have demonstrated Quality of Life (QoL) benefits for individuals with metastatic cancer. What is less known are the formal barriers that inhibit participation within this population. This study was a qualitative exploration that investigated the barriers to exercise and PA for individuals with metastatic cancer who were undergoing chemotherapy. The Health Belief Model (HBM) and its constructs (perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy) informed this research investigation. The researcher identified 12 subthemes that related to the HBM. Risk of infection in public spaces, fear of falling and age were unique findings. The HBM also proved to be a useful theoretical framework in understanding the barriers to exercise and PA for individuals with metastatic cancer, and should be considered in future research. A larger sample size is also necessary for future research.


title: Development of an end-effector system for autonomous spraying applications and radiation surveying

subject: Shotcrete Nutation Radiation Surveying Autonomous

abstract:
This thesis presents the design and testing of a scale proof-of-concept prototype end-effector system for autonomous shotcrete application and radiation surveying in underground uranium mining environments. The prototype end-effector system presented consists of two functionally distinct prototype tools that achieve the independent tasks of autonomous shotcrete spray pattern control and surface radiation surveying. The work of this thesis is part of a joint project known as the Mobile Autonomous Scanning and Shotcreting (MASS) robot that is currently under development at the University of Ontario Institute of Technology in cooperation with
Cameco Corporation. The MASS robot is a mobile manipulator system capable of autonomously facilitating the application of spray-able concrete (shotcrete) for excavation support and conducting remote radiological surveys of surfaces in hazardous underground mining and tunneling environments.
The first prototype tool presented is a novel, robotic shotcrete spraying tool that is capable of autonomously maintaining and adjusting its circular spray pattern diameter on target surfaces in response to changes in target surface distance. Control algorithms are presented that give the robotic shotcrete spraying tool the capability to produces advanced figure eight and spiral spraying patterns for surface preparation applications that involve spot filling deep surface cracks and pockets. Physical testing of the prototype tool empirically verified its ability to maintain circular spray pattern diameters at various target distances and demonstrated the application potential of the advanced figure eight and spiral spraying patterns.
The second prototype tool presented is a Geiger Muller tube based radiation detection tool that uses shielding and a single hole collimator in combination with precise robotic positioning in order to capture localized radiation measurements of surfaces within radiation rich environments. Physical testing of the prototype tool demonstrated its ability to create radiation survey profiles that distinctly characterized the radiological profile of test target surfaces embedded with various radioactive sources.


title: Exploring intrinsic learning in an augmented reality app for adults with autism spectrum disorder

subject:
Situated learning
Autism spectrum disorder
App
Augmented reality
Transit

abstract: Adults with autism spectrum disorder (ASD) display varying levels of social impairment that can manifest as difficulty with communicating, stereotyped behaviour, difficulty starting and maintaining relationships, and inflexible thinking (APA, 2013). The purpose of this study was to explore the relationship between learning and technology for adults with autism spectrum disorder. Specifically, to answer the research question: What are the effects of an augmented reality app on the development of intrinsic learning in individuals with ASD? The transportation app was developed by the researcher and was grounded in theories of situated learning, communities, augmented reality, and authentic learning. In order to measure intrinsic learning, an ethnographic case-study was conducted to look at three participant’s experiences with this app when asked to navigate TTC without the app and with the app. Participants completed three questionnaires to assess intrinsic learning as well as participated in a semi-structured interview. Both quantitative and qualitative data were analyzed for instances of intrinsic learning. The participants had different experiences from one another in regards to intrinsic learning, findings suggesting that participants displayed intrinsic learning when using the app. All participants viewed the app with some positivity and, when asked, stated that they would share it with a friend. Future research can improve on the functionality of the app as well as explore its use with other populations.


title: Optimal structure and efficient algorithm for max-min fair multi-group multicast beamforming

subject:
Max-min fair
SINR
MMSE
Beamforming

abstract:
In this thesis, we consider the max-min fair (MMF) multi-group multicast beamforming design to maximize the minimum signal-to-interference-plus-noise ratio (SINR) subject to transmit power limit. We obtain the optimal multicast beamforming solution structure for an arbitrary system configuration. We show that the optimal MMF solution has a weighted minimum mean square error (MMSE) filter structure and a similar structure to that of the quality-of-service (QoS) problem. Directly using the optimal beamforming structure, we propose two algorithms by either direct method via successive convex approximation (SCA), or solving the QoS problem
iteratively. For massive MIMO systems, we propose an efficient MMF multicast beamforming design based on the optimal solution structure. The semi-definite relaxation (SDR) method and an SCA-based method are applied to solve the problem with low-complexity. Simulation results show that our proposed methods that used optimal beamforming structure achieve near-optimal performance. Additionally, they have relatively low computational complexity compared with the conventional direct SDR method for large-scale antennas or user-per-group. Our proposed efficient methods show comparable performance to the optimal beamforming structure methods but with significantly lower computational complexity for massive MIMO systems.


title: Ray tracing large distributed datasets using ray caches

contributor:
Green, Mark
Qureshi, Faisal

subject: Visualization Cluster Sharcnet Simulation In-situ

abstract:
Many large scale simulations now produce datasets that are signi cantly
larger than can typically be stored in memory on a visualization system. Visualization
algorithms then become ine ective and stall since the data must be
paged to disk. Recently, in-situ visualization has received renewed attention
for visualizing large datasets that are distributed among many processors during
a simulation. It takes advantage of the fact that the full dataset is already
in main memory, distributed among multiple processors. Visualization in this
environment then requires communication which can be more expensive than
disk access. The goal of this thesis was to develop an in-situ visualization
technique using ray tracing that employs ray caches to reduce communication
overhead. Ray caches attempt to replace a communication operation with a
less expensive cache search operation. A prototype implemented on Sharcnet
shows ray caching can signi cantly improve overall performance at a small cost
to image quality.

abstract: University of Ontario Institute of Technology


title: The impact of individual differences on the interviewing success and post-training performance of investigative interviewers

subject:
Investigative interviewing
Aptitudes
Big Five
Interview performance
Training efficacy

abstract: In this thesis, whether and how personality characteristics affect the performance in investigative interviewing and the efficacy of training was examined in a three-step research design. In Study 1, the structure of a 50-item aptitudes scale, a modified and extended version of the Police Interviewing Competences Inventory (PICI), was assessed using a general population sample (N = 300), and a four-dimensional aptitudes scale was created. The four dimensions found were named as Humane (13 items), Communicative-Insisting (13 items), Self-controlled (9 items), and Careful-Tenacious (10 items). In Study 2, student participants (N = 154) completed the aptitudes and the Five Factor Model (FFM) scales, and then interviewed witnesses who watched a mock robbery crime video. Interviewer performance was assessed based on the amount of details they could elicit, the perception of the witness, and researcher ratings of behaviours and question usage. Three dimensions of the FFM were correlated with the success measures: Agreeableness with witness perception and appropriate questioning, Extraversion with researcher ratings and inappropriate questioning, and Openness with researcher ratings. Only the Communicative-Insisting dimension of the aptitudes scale predicted high researcher ratings. In Study 3, we used a policing student sample (N = 38) to investigate the impact of training on the interview performance and also to analyze how training effect interacts with personality measures when predicting the performance of participants. Overall, training increased the performance of participants in most of the success measures. The Humane dimension of the aptitudes scale and the Openness/Intellect dimension of the FFM predicted training efficacy. The post-interview performance of the participants was predicted by the Openness/Intellect, Agreeableness, Extraversion, and Neuroticism (negatively) dimensions of the Big Five and the Careful-Tenacious and Communicative-Insisting dimensions of the aptitudes scale. Findings might help police departments to identify potential successful interviewers and develop new training policies.


title: Encapsulated source contact dose estimates incorporating secondary electron emission

subject:
Contact dose rate
MCNPX
Secondary electron

abstract: Secondary electron emission generated at the surface of thin material from interaction with gamma rays form a significant component of the surface dose. The intensity of this emission is known to vary with material composition and incident radiation energies. The goal of this research effort is to estimate the emission strength from radioactive sources utilized in the early history of cancer Brachytherapy, and develop dose conversion factors from that data. Data was obtained by utilizing a comparative stochastic analysis, conducted with the Monte Carlo radiation transport code MCNPX. Emission intensities were measured at the surface of source encapsulation and at increasing distances in tissue equivalent material. It is shown that the results obtained correlate to the historical trends, however the electron component of the simulated emission is of greater by several orders of magnitude than that previously estimated. The dose conversion factors found from simulation will assign a higher absorbed dose than those currently published. The corollary is that the current published values are under attributing dose for a given radiation injury, which hinders effective treatment.


title: Simulation and modelling to develop a nanopore-based device for ricin detection

subject:
Nanopore
Ricin
Single-molecule detection
Biophysics
MD simulation

abstract: Nanopore-based protein detection represents an exciting opportunity to develop ultrasensitive diagnostic devices that are both portable and affordable. Aptamer-encoded nanopores detect target molecules by binding to them to facilitate a corresponding blockage of ionic flow through the pore. Molecular dynamics simulations are an effective method of quantitatively and qualitatively studying key design features and mechanisms of current blockage. This work uses coarse-grained Langevin dynamics simulations to explore various aptamer-encoded nanopore systems to facilitate the design of diagnostic devices to detect the bioterror agent, ricin. The optimal signal-to-noise ratio occurred when ricin could occupy and interact in a stable manner within a pore cylinder that was similar in size, as predicted by the steric exclusion model of current blockage. Interestingly, under certain conditions, ricin also elicited ionic current selectivity. The results presented in this thesis have practical implications for device design, and the methodology is well-positioned to efficiently study related systems.


title: Engaging adult literacy learners: investigating problem based learning object (PBLO) use as a possibility for implementing problem based learning (PBL) online

contributor:
vanOostveen, Roland
Desjardins, Francois

subject:
Problem based learning
Online learning environments
Engagement
Adult education
Literacy

abstract: Anecdotal evidence revealed that learners in an adult literacy program at a large school board in Ontario were disengaged - unable to identify opportunities to act in response to traditional pedagogy used to prepare them for science PLAR assessments. Given the evidence that Problem Based Learning Objects (PBLOs) engage adult learners in science, a similar approach was adopted. A PBLO was designed and introduced to four learners with the intent of fostering engagement in the form of “social practice.” The “Flow” framework was used to measure learner emotion, the means through which activity during PBLO use was investigated. In response to the online experience, learners were able to identify opportunities to engage; however, a longitudinal study is warranted to understand the engagement in terms of "social practice."


title: CORE: a framework for the automatic repair of concurrency bugs

contributor:
Bradbury, Jeremy
Green, Mark

subject:
Genetic algorithm
Concurrency
Automatic repair
Deadlock
Data race

abstract: Desktop computers now contain 2, 4 or even 8 processors. To benefit from them programs must be written to work in parallel. If writing good code is hard, writing good parallel code is much harder. Parallelization adds process communication and synchronization to the list of difficulties faced by programmers. It also adds new kinds of bugs not found in single-threaded code such as deadlocks and data races. In this thesis we develop the CORE (COncurrent REpair) framework. It automatically fixes deadlocks and data races in parallel Java programs. It uses a search-based software engineering approach to mutate and evolve the source code. In these mutants synchronization blocks are added, removed, expanded, shrunk or the synchronization variable is changed. Each potential fix is model checked or run through a thread noising tool that forces different thread interleavings to be explored.  Efficiently fixing data races and deadlocks in parallel Java programs is realized by combining two techniques. First, different forms of static and dynamic analyses are brought together to constrain the search space. Second, a genetic algorithm without crossover was implemented that uses both noising and model checking to determine fitness. These techniques are unified in the CORE framework. Different kinds of analysis better constrain the search space of the problem. Intelligent use of noising, model checking and incremental model checking are combined efficiently into a modern framework that help to increase the overall quality of concurrent software.  This thesis created three projects within the CORE framework, ARC-OPT, CORE-MC and CORE-IMC. First, static analysis from Chord and dynamic analysis from ConTest with fitness evaluation by thread noising from ConTest were combined in ARC-OPT. Second, JPF was integrated into the framework to analyze the source. Fitness was evaluated by JPF and ConTest. This version was called CORE-MC. Third, function header scanning for in-scope locks and incremental modelling support was added to CORE-MC to create CORE-IMC. Each project builds upon the previous and each was evaluated against a suite of test programs.


title: Multi-state system in a fault tree analsis of a nuclear based thermochemical hydrogen plant

contributor:
Naterer, Greg
Lu, Lixuan

subject:
hydrogen plants
thermochemical CuCI cycle
nuclear-based hydrogen generation
Cu-CI - - safety management
fault tree analysis
Cu-CI - - risk analysis

abstract:
Nuclear-based hydrogen generation is a promising way to supply hydrogen for this large market in the future. This thesis focuses on one of the most promising methods, a thermochemical Cu-Cl cycle, which is currently under development by UOIT, Atomic Energy of Canada Limited (AECL) and the Argonne National Laboratory (ANL).
The safety issues of the Cu-Cl cycle are addressed in this thesis. An investigation of major accident scenarios shows that potential tragedies can be avoided with effective risk analysis and safety management programs. As a powerful and systematic tool, fault tree analysis (FTA) is adapted to the particular needs of the Cu-Cl system. This thesis develops a new method that combines FTA with a reliability analysis tool, multi-state system (MSS), to improve the accuracy of FTA and also improve system reliability.


title: Analysis of heat transfer and fluid flow in an evaporating sessile droplet for evaporative cooling applications

subject:
Evaporation
Sessile droplet
Cooling
Phase change

abstract:
Cooling is of critical importance for a number of fields, particularly in microelectronic
devices and other miniaturized technology. The evaporation of the sessile liquid
droplet facilitates the phase change of that liquid and provides cooling to the system,
because a large amount of latent heat is required to change the phase. Evaporation
takes place at the liquid-vapour interface, so to enhance the phase change process, it
is essential to understand the interfacial energy transport mechanisms involved in
transporting energy to the liquid-vapour interface from the solid substrate and the
vapour surrounding. A series of experiments were conducted under different
experimental conditions to understand interfacial energy transport in an evaporating
sessile droplet. The experimental results demonstrate the effect of the ambient and
substrate temperature on the evaporation process and the relative contributions of
the conduction energy transport and other modes of energy transport in the total
energy required for the phase change process.


title: Exploring subjective and objective localized muscle fatigue responses at recommended upper limb ergonomics limits

subject:
Muscle fatigue
Psychophysics
Ergonomics
Upper extremity injury
Repetitive work

abstract: Localized muscle fatigue (LMF) has been associated with numerous negative outcomes, including a reduction in task performance and development of musculoskeletal injury. Thus, the quantification of LMF development in response to occupational task demands has become a major focus in the ergonomics literature. In this thesis, Study 1 showed how a familiarization session, including targeted feedback on ratings of perceived fatigue (RPF), resulted in a significant improvement in error between RPF and measures of force output and electromyography. Study 2 compared the LMF response at three different “acceptable” limits along the ACGIH® threshold limit curve, which describes acceptable relative force intensity for a given level of repetitive work (i.e. duty cycle). Exposures at higher duty cycles (and lower force intensity) were found to elicit the largest LMF responses. This thesis concludes with practical recommendations to help ergonomists better assess and prevent the accumulation of excessive LMF in the workplace.


title: Implementing a multi-sport skills camp for girls ages 8-11 with autism spectrum disorder

subject:
Autism spectrum disorder
Girls
Camp intervention
Fundamental motor skills
Physical activity

abstract: Children with Autism Spectrum Disorder (ASD) display delayed fundamental motor skills (FMS) in comparison to their peers with typical development. Girls with ASD, typically display even less adequate FMS than boys with ASD, and are less physically active. The purpose of this study was to implement a one-week multi-sport skills camp intervention to improve FMS, physical activity (PA), physical self-perceptions, and adaptive behaviour of school aged girls with ASD (n=13). Results indicated significant improvements in FMS following the multi-sport camp intervention; improvements were maintained at the 8-week follow up. No significance was found regarding PA. Results indicated significant improvements in physical self-perceptions, sport/athletic competence and social skills. Significant correlations were present between FMS and physical self-perceptions, and between physical self-perceptions and social skills. The results of this study indicate that a multi-sport skills camp intervention can be effective at improving FMS, physical self-perceptions and social skills among school aged girls with ASD.


title: Reconstructing experience of childhood cancer: a narrative inquiry

contributor:
Sanchez, Otto
Schwind, Jasna

subject:
Narrative inquiry
Childhood cancer
Patient illness narrative

abstract:
Many childhood cancer survivors experience long-term effects from their illness long
after their treatments are over. In order to more fully understand the impact these effects
have on a young person’s life, there is a need for more patient illness narratives. Using
Connelly and Clandinin’s Narrative Inquiry methodology, I explored the experience of a
young adult survivor of childhood cancer. My co-participant and I engaged in narrative
interviews and creative self-expression activities. To reconstruct and critically examine
the story of her childhood cancer experience, I used two theoretical frameworks,
Erikson’s (1968) Psychosocial Stages of Development and Cellular Memory, based on
Porges’ Polyvagal Theory (1995). The narrative patterns that emerge are: relationships,
identity and the embodied experience. The co-participant’s story is re-presented in a
letter, accompanied by a poem, addressed to healthcare professionals. Implications for
healthcare practice include the need for increased sensitivity to patient’s lived experience
of the illness. More specifically, there is a need for further education of healthcare
professionals on the long-term effects of childhood cancer that include mind-body-spirit.


title: A study of undergraduate health science students' perceptions, navigational choices, and learning outcomes with IPSims simulative learning environment

contributor:
Vargas Martin, Miguel
Tashiro, Jayshiro

subject:
Simulation
Online simulated learning environments
Misconceptions
IPSims

abstract: Simulated learning environments are becoming a more popular format for the delivery of healthcare education. These environments include but are not limited to simulated online learning environments, serious games, task trainers, and, electronic mannequins. Presently there is a lack of understanding of how the learning environment impacts students’ disposition to engage in learning processes and how learner satisfaction with the environment impacts learning outcomes. This preliminary descriptive study utilizes methods such as traditional statistical analysis and Association Rule mining. This study will investigate how students perceptions of the simulative learning environment IPSims (Interprofessional Simulations) usability impacts learning outcomes, and how these environments may impact student disposition to engage in learning. The participants (n= 58) were undergraduate health science students studying at the University of Ontario Institute of Technology. The data analysis provides insight into how simulative learning environments can impact student engagement in learning processes. Study strengths and limitations are identified along with future considerations.


title: Experimental investigation of an integrated solar driven wastewater treatment system for trigeneration applications

subject:
Efficiency
Wastewater treatment
Energy
Exergy
Hydrogen production

abstract:
Hydrogen is a promising alternative as an energy carrier (and carbon-free fuel) to meet the global power demand. Hydrogen production systems can efficiently harvest energy from renewable sources. Even though photo-electrochemical systems offer an attractive potential for both hydrogen production and wastewater treatment systems, their application in industrial scales is not satisfactory.
This thesis study proposes a trigeneration system for electricity, hydrogen and clean water production. TiO2 photocatalyst is used in a photoelectrochemical (PEC) reactor, which cleans the water via Fenton-like process and produces hydrogen. A novel solar thermoelectric generator (TEG) unit drives the reactor. For the hot side, the phase change material (PCM) which is heated by the concentrator feeds TEG, and the wastewater stream provides the cold surface. The PEC system is investigated experimentally while the design and calculations of the TEG-PCM sub-system are analyzed theoretically in this study. Moreover, in this study, the synergistic effects of advanced oxidation reactions (AOPs) in a combination of TiO2 photocatalysis are comparatively investigated for hydrogen production and wastewater treatment applications. The synergistic effects of Fenton, Fenton-like, photocatalysis (TiO2/UV) and UV photolysis (H2O2/UV) are investigated individually and in a combination of each other. The effects of various parameters, including pH, type of the electrode and electrolyte and the UV light, on the performance of the combined system are also investigated experimentally.
A numerical modeling study is performed to predict the temperature, heat transfer rate and generated power distributions on the thermoelectric generator which is included in the integrated system. The thermodynamic properties of the matter flows at each stage and state point are obtained for the integrated system. The overall energy and exergy efficiencies of the integrated system are 5.2% and 5.5% respectively. The total cost rate of the system is determined to be 0.28 $/h from exergoeconomic analysis results. After 40 minutes of the operation time of the PEC reactor under 2.3V of practical cell potential and 60°C of cell temperature, the reactor produces 22.6 mg of hydrogen and removes 87% of COD. The proposed TEG unit configuration generates 551.2 W of electricity with 7.46% heat to electricity efficiency for the case when the temperature of wastewater is 25°C, and the molten salt is at phase changing temperature of 323°C.


title: A reliability-aware framework for service-based software development

subject:
Availability
Recovery block
Reliability
Software fault-tolerance
Web services

abstract: It is becoming common to see software applications taking advantage of web services available publicly to meet their needs, rather than developing an in-house solution. This introduces the problem where failures can occur on the network, or on the service provider, outside the influence of the developer. This thesis proposes a reliability-aware framework with a focus on availability, which applies a recovery block scheme to services provided by different developers. The proposed framework allows developers to specify alternative services which meet the core specifications of their primary service. When a failure is determined to have occurred, the request to the primary service is mapped to an alternative service. A prototype has been developed as a proof of concept, which has been evaluated on metrics based on potential use cases. The experimental results show that the system is successful at providing availability when failure occurs, at a cost to overall performance.


title: Non-linear model predictive control for autonomous vehicles

contributor:
Eklund, Mikael
Milman, Ruth

subject:
Model predictive control
Autonomous vehicles
CarSim
Optimization
Gradient
Matlab
Trajectory tracking
Real-time

abstract:
With the advent of faster computer processors and better optimization algorithms,
Model Predictive Control (MPC) systems are more readily used for real-time applications.
This research focuses on the application of MPC to trajectory generation of autonomous
vehicles in an online manner. The operating environment is assumed to be unknown with
various different types of obstacles. Models of simplified 2-D dynamics of the vehicle are
developed, discretized and validated against a nonlinear CarSim vehicle model. The developed
model is then used to predict future states of the vehicle. The relationship of the
weight transfer to the tire slip angle is investigated. The optimal trajectory tracking problem
is formulated in terms of a cost function minimization with constraints. Initially, a gradient
descent method is used to minimize the cost function. A MATLAB based MPC controller
is developed and interfaced with CarSim in order to test the controller on a vehicle operating
in a realistic environment. The effects of varying MPC look-ahead horizon lengths on
the computation time, simulation cost and the tracking performance are also investigated.
Simulation results show that the new MPC controller provides satisfactory online obstacle
avoidance and tracking performance. Also, a trajectory tracking criterion with goal point information
is found to be superior to traditional trajectory tracking methods since they avoid
causing the vehicle to retreat once a large obstacle is detected on the desired path. It is further
demonstrated that at a controller frequency of 20Hz, the implementation is real-time
implementable only at shorter horizon lengths.


title: Optimization algorithms in compressive sensing (CS) sparse magnetic resonance imaging (MRI)

subject:
Compressive sensing
Sparse MRI
Convex optimization

abstract:
Magnetic Resonance Imaging (MRI) is an essential instrument in clinical diag-
nosis; however, it is burdened by a slow data acquisition process due to physical
limitations. Compressive Sensing (CS) is a recently developed mathematical
framework that o ers signi cant bene ts in MRI image speed by reducing the
amount of acquired data without degrading the image quality. The process
of image reconstruction involves solving a nonlinear constrained optimization
problem. The reduction of reconstruction time in MRI is of signi cant bene t.
We reformulate sparse MRI reconstruction as a Second Order Cone Program
(SOCP).We also explore two alternative techniques to solving the SOCP prob-
lem directly: NESTA and speci cally designed SOCP-LB.


title: The effects of labeling and stereotype threat on offender reintegration

subject: Offenders Labeling Reintegration Stereotype Threat Employment

abstract: After their release from prison, offenders are faced with many hardships that hinder their reintegration efforts. Often, offenders are stereotyped and face community exclusion due to their criminal record. Much of the literature on reintegration has focused on the way in which society stereotypes offenders, but not how offenders interpret and internalize these stereotypes. This study examines the way offenders internalize the stereotypes associated with having a criminal record, and how this affects their reintegration. Data was gathered by conducting 18 in-depth interviews with offenders at the John Howard Society in Toronto. The interviews showed that all participants felt that they had been negatively labeled by others based on the fact that they have a criminal record and/or spent time in prison. Additionally, five participants indicated experiencing stereotype threat, and believed this phenomenon to have had a negative impact on their ability to reintegrate back into society.


title: Probabilistic impact of charging plug-in electric vehicles on the electric energy distribution systems

subject:
Monte Carlo (MC) methods
Electric vehicles
Power distribution

abstract: The electric power grid including generation, transmission, and distribution system usually serving the loads in the consumer’s side through distribution transformers. Generally, increasing the demand requires increasing the supply and therefore any increasing in the consumer’s side must be covered and delivered by the supply. The distribution transformers are serving the existing residential loads and hence any increase in the power demand must be supplied by that distribution transformers. Since charging these vehicles may have negative impacts on the distribution transformer’s insulation life, the work presented here looks into the probabilistic assessment of the impact of charging plug-in electric vehicles on the distribution transformer’ life time. This thesis also considers the effect of time of use price (TOU) and different charging levels. The results reveal that charging the vehicles as two clusters may significantly reduce the loss-of-life of the distribution transformers compared to charging the vehicles as one cluster.

abstract: University of Ontario Institute of Technology


title: A case study for evaluating nursing and health sciences student satisfaction with e-learning

subject:
E-learning
Nursing student
Student satisfaction
GPA
Health sciences student

abstract: An increased demand for e-learning in nursing and health sciences education is emerging and not enough is known about factors determining nursing student satisfaction with e-learning, therefore studies clarifying how to design and implement efficient e-learning programs to increase student satisfaction are necessary. This case study helps fill this gap by investigating the factors influencing nursing students’ satisfaction with e-learning and the relationship between satisfaction and GPA in healthcare higher education. A web-based questionnaire collected data on various aspects of e-learning and 140 students from University of Ontario Institute of Technology participated. Statistical analysis was completed and responses to open-ended questions were explored using thematic open-coding. Results revealed the most highly influential factors on nursing student satisfaction being perceived liking and perceived usefulness, while usability and communication & teaching factors having less predictive power to the student satisfaction. Another important finding is that any potential student that wants to pursue studies in a health related program in the university where e-learning is part of the program, who has a high level of satisfaction will be able to obtain a good GPA. Major barriers in using e-learning were identified in the area of communication, course management, feeling of being disconnected, and technology issues. In conclusion, we believe the findings of this study add a new perspective on satisfaction factors with e-learning for nursing students and describe the link between their satisfaction level and GPA. Further research is required to explore how e-learning program design can address the barriers to e-learning identified in this study and further explore the conclusions of this study to other nursing and health sciences programs at other universities.


title: A robust and efficient autonomous exploration methodology of unknown environments for multi-robot systems

subject:
Multi-Robot Systems (MRS)
Frontier exploration
K-means
Robot Operating System
Optimization

abstract: Multi-robot systems can provide effective solutions for exploring and inspecting environments where it is unpractical or unsafe for humans, however, adequate coordination of the multi-robot system is a challenging initiative. A robust and efficient methodology for exploration of unknown environments is presented using a k-means method to improve traditional task allocation schemes. The k-means method proposed is an efficient technique due to the algorithm’s quick convergence time and its ability to segment a previously unknown map in a logical manner. In this method, a global executive receives frontiers from local robots, filters them, clusters them using the k-means method, and then reassigns them to the agents. A framework is developed in Robot Operating System (ROS) to test the effectiveness of the k-means method. The method is tested over a series of simulations and real-world tests, where it provided significant reductions in exploration time and distance travelled compared to other methods.


title: Flow-sound interaction mechanism of a single spirally finned cylinder in cross-flow

subject:
Flow-excited acoustic resonance
Flow-sound coupling
Spirally finned cylinders
Vortex shedding
Wave structure

abstract: Over the years, some effort has been expended in the improvement of heat transfer performance in tubular heat exchangers. This can be achieved by adding different types of fins to the outer tube surface, effectively increasing convective heat transfer. However, the addition of fins may lead to the generation of severe noise, caused by the coupling between the vortex shedding frequency and one of the acoustic cross-modes of the duct housing the finned tubes. This may reduce the service life of the heat exchangers, and adversely affect the health of individuals working in the proximity of such noise. Since the flow-acoustic phenomenon of finned tubes are not well understood, it can be dangerously unpredictable. Therefore in this thesis, the flow-sound interaction mechanism of a single spirally finned cylinder in cross-flow is investigated. Moreover, a simple noise control technique is proposed to suppress the onset of acoustic resonance excitation.


title: Experimental and theoretical investigation of novel phase change materials for thermal applications

subject:
R134a clathrate
Cooling
Heat transfer
PCM
Additives

abstract: An experimental investigation is conducted to test the thermal properties, behaviour and characteristics of R134a clathrates with additives, as phase change materials (PCMs). PCMs’ charging characteristics are analysed and evaluated for cooling applications. The formation of refrigerant clathrates is investigated due to their potential use in active as well as in passive cooling applications. PCMs are formed using R134a clathrate and distilled water with different refrigerant fractions and five different additives. The main objective of using additives is to study their potential for enhancing the clathrate formation and their thermal properties under direct contact heat transfer. PCMs are formed in glass tubes to determine their freezing onset time, transformation time and thermal properties. The thermal properties determined are the liquid phase thermal conductivity, mushy phase thermal conductivity, and specific latent heat of the PCMs. Refrigerant R134a fractions of 0.15, 0.2, 0.25, 0.3, 0.35 and 0.4 are used to form clathrate. For the additives, ethanol, sodium chloride, magnesium nitrate hexahydrate, copper and aluminum are used. Additive mass fraction is varied from 0.01 to 0.05 with 0.01 interval. Time for on set and end set is recorded after regular intervals. PCM’s temperatures, after regular intervals, at two different locations inside the tube are also recorded. Discharge tests are also conducted for which the PCMs are used to cool the hot air as well as to cool down a battery. Energy and exergy analyses are performed to assess PCMs’ performance. R134a fraction of 0.35 is found to be the best mass ratio for clathrate formation while Ethanol as best additive.


title: A mixed-method approach to analyze the robustness of natural language processing classifiers

contributor:
El-Khatib, Khalil
Sankaranarayanan, Karthik

subject:
Adversarial machine learning
Robustness evaluation
Natural language processing
Text classification
Information visualization

abstract: Natural language processing algorithms (NLP) have become an essential approach for processing large amounts of textual information with applications such as spam, phishing and content moderation. Malicious actors can craft manipulated inputs to fool NLP classifiers into making incorrect predictions. A large challenge with evaluating these adversarial attacks is the trade-o_ between attack efficiency and text quality. Higher constraints on the attack search space will improve text quality but reduce the attack success rate. In this thesis, I introduce a framework for the evaluation of NLP classifier robustness. Black-box attack algorithms are paired with a threat modelling system to apply a customizable set of constraints to the adversarial generation process. I introduce a mixed-method experimental design approach that combines metrics that compare how many adversarial documents can be made versus the impact the attack has on the text's quality. Measuring the attack efficiency involves combining the computational cost and success rate of the attack. To measure the text quality, an experimental study is run in which human participants report their subjective perception of text manipulation. I present a set of equations to reconcile the trade-offs between these tests to find an optimal balance. This pairing bridges the automated evaluation of the classifier decisions with the semantic insight of human reviewers. The methodology is then extended to evaluate adversarial training as a defence method using the threat modelling system. The framework is also paired with a collection of visualization tools to provide greater interpretability. Domain-agnostic tools for classifier behaviour are first presented, followed by an interactive document viewer that enables exploration of the attack search space and word-level feature importance. The framework proposed in this thesis supports any black-box attack and is model-agnostic, which offers a wide range of applicability. The end objective is a more unified, guided and transparent way to evaluate classifier robustness that is flexible and customizable.


title: Design, analysis and experimental investigation of a new scroll expander based trigeneration system

subject:
Trigeneration
Scroll expander
Heat engine
Ejector
Exergy

abstract:
Current technologies of using conventional energy produce a large amount of waste heat which can potentially be recovered in the form of useful work to use in our day to day life. This initiative not only optimizes the energy usage but also contributes to mitigating
environmental impact of fossil fuel. There are also two main sources of renewable energy, solar and geothermal that can be used as an alternative to fossil fuel based options. Harnessing of this energy with appropriate low cost technology could be a promising method of alternate energy utilization. However, there are some developed
technologies which are already in use to generate medium to large scale of power or power and heat (co-generation). But small scale trigeneration with a single source of energy has not yet been developed. In this research work a small scale trigeneration
system is designed, built and experimentally investigated for simultaneous generation of power, heating and cooling.
This integrated system combines a power and cooling cycles where the source heat is used to generate power through a scroll expander and a portion of the heat is used in an ejector cooling system. The residual heat which is normally released to the environment in this type of power cycle is captured as much for hot water heating or space heating. Ammonia-water is used for both the power cycle and the cooling cycle.
The experimental investigation of this thesis work analyzed the performance of a scroll based heat engine working with low temperature heat source within the trigeneration facility. Coupling trigeneration and renewable makes a very strong scheme to supply not only low-carbon electricity and low-carbon heat, but also cooling, in an integrated system with high utilization factor. The first part of the work is to study the performance of the heat engine that consists of custom built expander, boiler and condenser in an ammonia water Rankine cycle system. The second part is to determine the utilization of the heat engine driven by low grade heat source in a small scale trigeneration unit. Ammonia water is suitable for low temperature Rankine power cycle, because of its non-azeotropic properties. The source of heat can be at relatively low and intermediate temperatures in the range of 80°C- 200°C. This heat can be derived from a multitude of sources including solar panel collectors, biomass combustion, biofuel, recovered waste heat etc. Due to the trigeneration feature, the utilization factor of the heat source or fuel energy with this system exceeds 90%. The experimental result shows a maximum isentropic efficiency of 67% and an overall energy efficiency of maximum 7% at 120°C  source temperature, while the exergy efficiency is about 30%. The experimental result also shows that the concentration of ammonia is a dominant factor in determining the optimum efficiency with a range of ammonia-water mixture. 40% ammonia concentration found optimum, however higher concentration drastically reduces the work output. In the trigeneration facility, the cooling and heating can be adjusted without affecting power generation. Finally, it can be concluded that from the optimization results, if mass production is put in place, the system shows a high economic competitiveness with respect to conventional power generation methods which require multiple individual systems to provide the same results. This system is very new and novel with unique features, which would resolve various energetic and environmental issues and provide potential solutions to residential applications. It is also aimed to make such systems suitable for restaurants, hospitals, commercial buildings, social centres, farming facilities and to use in remote locations. The ultimate goal is to produce a viable commercial product.


title: Everybody's got a story: examining the building of empathy and understanding for the bully, the bullied, and the bystander through digital storytelling

subject:
Digital storytelling
Bullying
Engagement
Digital literacies
Empathy

abstract: Digital storytelling as a pedagogical practice has been extensively explored as a means of increasing engagement, developing 21st century skills such as creativity, critical thinking, collaboration and communication, and refining digital literacies in students. However, there is a lack of data on how the use of multimodal digital tools can be used to explore pervasive social issues such as bullying in adolescents. In this study, a group of grade seven students provided their views and self-assessed their levels of empathy and understanding for victims of bullying, bullies and bystanders prior to and after the completion of a digital storytelling project. Using Likert scale data, along with an in-depth content analysis of the stories and presentations the students produced, the study explored whether participation in this digital storytelling project led to a noticeable and measurable impact on their understanding of and empathy for victims of bullying, bullies and bystanders.


title: Using asynchronous video interviews to enhance self-awareness of video communication skills in a community college setting

contributor:
Lesage, Ann
Hunter, Bill

subject:
Asynchronous video interviews
Self-awareness
Communication skills
Video communication skills
Peer assessment

abstract: Asynchronous video interviews are an emerging trend in the hiring process for assessing communication skills crucial in interviews. Industry leaders perceive a gap between communication skills and work-readiness of college graduates. That gap may reflect a lack of self-awareness. The purpose of this study was to explore the value of using a peer-assessed, asynchronous video interview assignment to enhance self-awareness of communication skills on video. Quantitative and qualitative data were collected using two questionnaires and two semi-structured interviews. The findings suggest that students became more self-aware of their communication skills, revealed experienced difficulties using body language and eye contact, showed low confidence levels recording self-facing videos, and had a preference for anonymous peer assessment. There was also a positive relationship between cognitive and affective attitudes towards asynchronous video interviews.


title: Active balancing of lithium-ion cells for maximum power discharging

subject: BMS Battery Management System Balancing

abstract: The future of Electric Vehicle’s (EV) depends on the adoption of the technology. Currently the limiting factor for EV adoption is mainly the initial cost, the driving range, charging capability, and the battery life. The Battery Management System (BMS) in any Lithium chemistry battery system is used to keep the cells in the optimal operating conditions. The BMS in standard EV batteries employ series cell balancing only while charging. The discharge balancing technique can be used to increase useable capacity from an EV battery because at the end of a cycle the stronger cells have some remaining capacity which can used to assist the weaker cells. This work explores the difference in useable capacity with active cell balancing vs. passive balancing for both new and aged cells near End of Life (EOL). In this work the proposed discharge balancing technique has been researched, simulated, and implemented in hardware testing.


title: Enhancement of bioactive glass biocompatibility by  deposition of titanium nanofibres generated by the  High Intensity Laser Induced Reverse Transfer Method (HILIRT)

subject:
Laser nanofabrication
Nanofibrous biomaterials
Biocompatibility
Transparent materials

abstract: A literature review was done in order to understand the structure and properties of the surface of bioactive glass and how to make this structure biocompatible with the human body. In this research, glass biocompatibility was increased using a deposition method called high intensity laser induced reverse transfer (HILIRT), and the samples were utilized as enhanced-biocompatibility bioactive glass (EBBG) with a correspondent nanofibrous titanium (NFTi) coating. HILIRT is an ultrafast laser method for improving implants for biomedical applications and provides a thin film of NFTi on the glass substrate. The proposed method in which NFTi samples with different structures are synthesized at various laser parameters such as power, frequency and pulse duration does not have any of the disadvantages of conventional methods such as etching. Physical properties, cell compatibility and adhesion of these NFTi prepared with different laser parameters before and after immersion in simulated body fluid (SBF) were compared.


title: Virtual communities of practice in simulation-based healthcare education: participation factors and content value assessment

subject: VCoPs Simulation Online Education Community

abstract: This study is the first known formative analysis of simulation-based healthcare education virtual communities of practice (VCoPs). The goal of this study was to analyse the frequency of participation, factors that influence participation, and strategies used to assess the value and credibility of content in simulation-based healthcare education VCoPs. A sequential mixed-methods approach was used to assess participation and content assessment factors for a sample of 100 online survey respondents and five semi-structured interviews. Participation frequency was directly observed in 11 simulation-based education VCoPs for a one-year period between September 1, 2014 and August 31, 2015. Simulation-based healthcare education VCoPs that were hosted on LinkedIn had poor user engagement compared to VCoPs hosted as independent discussion forums. Qualitative analysis suggested that the perceived unmoderated and commercial nature of LinkedIn VCoPs may have driven low participation rates. Factors that were empirically associated with community participation rates included platform ease of use, trust in the community, direct and indirect personal benefits, self-efficacy and psychological safety. In this study, VCoPs participants rarely engaged in a systematic process of content credibility and value assessment. Rather, heuristic shortcuts were leveraged to assess content, including reputation, enforcement, self-confirmation, expectancy violation, and persuasive intent.


title: An exploration of artistic creation in makerspaces and youth identity

contributor:
Laffier, Jennifer
Hughes, Janette

subject:
Artistic expression
Makerspaces
Identity formation
At-risk youth
Positive youth development

abstract: The purpose of this qualitative case study was to understand how engagement in the arts in maker sessions might contribute to healthy identity development for youth experiencing risk factors in a maker-settings. Youth utilized different maker and technology tools, as well as art mediums. Data (observation notes, transcribed sessions, art creations, participants descriptions) was collected and analyzed from three participants to determine how they experienced the artistic process in the maker sessions and how this contributed to their identity formation. Findings indicate that the artistic process in the maker space program supported the youth’s identity formation in a positive manner, specifically in four domains: exploration, character and self-esteem, industry and confidence, and social and emotional competency. Although youth may not have reached full identity integration during this time, they were able to explore aspects of their identity in a safe and supportive environment and view themselves as artists and makers.


title: Pourbaix diagrams at elevated temperatures: a study of Zn and Sn

subject:
Pourbaix diagrams
Corrosion
Elevated temperature
Solubility

abstract:
Metals in industrial settings such as power plants are often subjected to high
temperature and pressure aqueous environments, where failure to control corrosion
compromises worker and environment safety. For instance, zircaloy (1.2-1.7 wt.% Sn)
fuel rods are exposed to aqueous 250-310 oC coolant in CANDU reactors. The Pourbaix
(EH-pH) diagram is a plot of electrochemical potential versus pH, which shows the
domains of various metal species and by inference, corrosion susceptibility. Elevated
temperature data for tin +II and tin +IV species were obtained using solid-aqueous phase
equilibria with the respective oxides, in a batch vessel with in-situ pH measurement.
Solubilities, determined via spectroscopic techniques, were used to calculate equilibrium
constants and the Gibbs energies of Sn complexes for E-pH diagram construction. The
SnOH3+ and Sn(OH)
species were incorporated, for the first time, into the 298.15 K and
358.15 K diagrams, with novel G ͦ  values determined at 358.15 K.


title: A new approach to neutron spectrometry with multi-element scintillators

subject:
Neutron spectrometry
Scintillators
Radiation detection
MCNPX
Neutrons

abstract:
The combined effects of the nuclear industrial renaissance, the events of 9/11, and the Fukushima disaster have had a significant impact on the research and development of radiation detection instrumentation. Notably, there is ample worldwide scientific research effort into a better understanding of the material properties and nuclear interactions with a view to support the improvement of radiation detection and measurement. These improvements are spurred by the heightened security requirements that entail the monitoring of contraband material including explosives in transit, and the need to enhance occupational safety as well as environmental radiation protection in respect to nuclear power generation. Moreover, the regulatory authorities require routinely employed radiation detection and measuring devices in nuclear installations to meet the revised standard specifications in terms of their design and performance.
Currently, there is no neutron dosimeter/spectrometer that can meet the requirements in terms of size and performance. In particular, the requirements for high sensitivity, spectroscopic features, and determination of operational quantities to enable radiation protection decision making have resulted in a closer examination of the basic physics of the radiation interactions in detector materials.
Neutron dosimetry is regarded as the last frontier in radiation protection. Due to the large span of neutron energy and the strong energy dependence of the dose to fluence coefficient, neutron dosimetry requires the knowledge of the neutron spectra for any accurate neutron dose quantification. As a result, spectrometry is a precursor to determine dosimetry quantities and spectrometers are therefore vital to determine and characterize radiation fields present to individuals as they provide information about the radiation intensity and energy spectra. However, current spectrometers have many drawbacks and limitations in different aspects. From one side, fast spectrometry currently uses the scattering process on hydrogen rich materials and uses complicated unfolding techniques to extract the energy spectra. From another side, neutron fields are inherently mixed with a gamma component and therefore, it is paramount to distinguish each component since their contribution to the dose equivalent is weighted differently. More specifically, the challenge becomes more profound with neutrons in the energy range between 10 keV and few MeV. These challenges are mainly due to:
• The drastic change in the dose-to-fluence conversion coefficient that increases by a factor of 40;
• The low sensitivity of the neutron sensors used in neutron spectroscopy (low cross section);
• The poor resolution of the detectors, which makes accurate neutron spectrometry difficult to achieve.
However, by exploiting new developments and high sensitivity scintillators, in this thesis, a new approach has been adopted using different nuclear reaction processes with different contents of scintillating material. More specifically, two nuclear reactions, i.e. (n,α) and (n,p), on two different elements have been used to carry out neutron spectrometry.
In addition, this thesis aims to investigate the spectrometric properties of scintillating materials as a first step to establish a platform for developing a neutron spectrometer/dosimeter.
In terms of methodology, the thesis has taken an empirical approach in studying potential sensors that can be used for neutron spectrometry. Four scintillators have been explored and studied. Each scintillator corresponds to a particular energy region. The first part of the thesis consists of extensive Monte Carlo calculations to optimize the sensor’s isotope contents, while the second part consists of conducting a series of experiments using three main facilities, namely an AmBe source of 120 mCi, a neutron generator of 2.5 MeV neutrons at the University of Ontario Institute of Technology, a KN Van De Graaff accelerator at McMaster University, and gamma ray sources with different energies. All sensors have been used in conjunction with a miniature data acquisition system that consists of a multi-channel analyzer, mounted on a photomultiplier, and controlled by software to operate, control and analyze the output data. The time characteristics of the output pulse, such as integration time and rising time, have been optimized for each sensor.
The thesis presents a thorough literature review, a comprehensive methodology of the study, a description of the used facilities and the results of the simulation data with four different sensors along with the experimental work carried out at the aforementioned facilities. The response functions of each scintillator to a given radiation type and energy has been analyzed and discussed. Furthermore, the sensor’s potential for use in neutron spectrometry/dosimetry has been assessed for future work.


title: Sparse signal representation based algorithms with application to ultrasonic array imaging

subject:
Sparsity
Ultrasonic array imaging

abstract:
We address one- and two-layer ultrasonic array imaging. We use an array of transducers to inspect the internal structure of a given specimen. In the case of one-layer imaging we also address the problem of mode conversion. We propose a sparse signal representation based method for imaging solid materials in the presence of mode
conversion phenomenon. In the case of two-layer imaging we model the signal propagation effect using Huygens principle and Rayleigh-Sommerfeld diffraction formula. We then use this model to develop a sparse signal representation based imaging technique for a test sample immersed in water. Moreover, we develop a new sparse Bayesian technique. In the model that we develop, the reflectivity coefficients of the desired reflectors are nonnegative real numbers and sparse in nature. Therefore, we use Weibull distribution function with two hyperparameters, namely the shape parameter and the scaling parameter, to model the prior distribution function of the reflectivity coefficients of the reflectors. As we show, the Weibull distribution, whose scale parameter obeys the inverse Gamma distribution, will enforce sparsity. We then propose a method for estimating the shape parameter of the Weibull distribution using Mellin transform.


title: The role of interprofessional collaboration on the discharge planning in the neonatal intensive unit

subject: Interprofessional Practice Collaboration Discharge Planning

abstract:
Rationale: Interprofessional collaboration (IPC) occurs when “multiple health workers from different professional backgrounds work together with patients, families, careers and communities to deliver the highest quality of care” (WHO, 2010, p. 13). Successful discharge planning for patients from hospitals is dependent upon IPC (Shepperd et al., 2004). The purpose of this study is to identify and examine barriers or facilitators to IPC as they pertain to discharge planning on a neonatal intensive care unit (NICU).
Methods: Case study design using an online survey, participant observation and semi-structured interviews for data collection. Healthcare workers on a NICU at a large Canadian teaching hospital were surveyed to determine their views on the discharge planning process, leadership and IPC. Participant observations took place during the weekly IPC rounds to observe the healthcare workers when discussing discharge plans and to identify key informants for interviews. Based on these observations, 10 health care workers were selected to interview to gain a more in depth understanding of IPC in the discharge planning. Data collection occurred from December 2010 to February 2011.
Results: Survey results (n=66) indicate that the majority of healthcare workers on the NICU support IPC. However, the interview data demonstrated that problems arose during an emergency discharge. An emergency discharge occurs when an existing patient on the NICU needs to be discharged to another unit in order to provide a bed for a new admission. The lack of effective communication, role clarity issues, and a need for mutual respect act as barriers to the full participation of all members of the interprofessional team in an emergency discharge.
Conclusions: Defining the context is important; IPC works well in a non-emergency situation on the NICU. The level of involvement of the healthcare workers in IPC varies due to previous experience working on interprofessional teams (IPT). The medical lead is responsible for making the decision about a discharge. However, what has been identified as important is an IPC leader who is responsible for ensuring that all information from the IPT members is accessible to inform the medical lead.


title: Design and performance evaluation of data dissemination and hovering information protocols for vehicular ad hoc networks (VANETs)

subject:
Vehicular ad hoc networks
Data dissemination
Hovering information
Vehicle-to-vehicle

abstract:
Robust and efficient communication protocols for Vehicular Ad Hoc Networks (VANETs)
are still an open topic in the literature. Because of that, our attention has been gathered
by the Data Dissemination and the Information Hovering protocols for VANETs.
For most of the VANETs' applications the data dissemination is a crucial process.
Also, for many of them the availability of information over some time in a bounded
region, or a Hovering Information protocol, is a key feature. Hence, in this thesis we
are proposing two data dissemination protocols and one information hovering protocol
for VANETs. Furthermore, we evaluate the performance of these protocols by conducting an extensive simulation experiment and comparing their effectiveness with other relevant protocols in the literature. As could be seen in the results shown in the thesis, the proposed protocols outperform the other schemes regarding various evaluation parameters as Delivery Ration, Total number of rebroadcast packets, etc.

abstract: University of Ontario Institute of Technology


title: Tuberculosis screening in a cohort of individuals diagnosed with HIV in Ontario during 2001 to 2009

subject: Tuberculosis TB HIV IGRAs

abstract:
Tuberculosis (TB) is a preventable and a treatable disease yet it is considered to be one of the
most common infections seen in HIV. People who are infected with HIV are 20 times more
likely to develop TB than those without HIV. Globally, there are nearly 40 million people living
with HIV and at least one-third of them are infected with TB. Ontario accounts for the highest
number of TB cases in Canada yet HIV-TB co-infection in Ontario is not well described. Despite
the close relationship between TB and HIV and increasing efforts to fight both concurrently, TB
continues to create economic and social burden in HIV infections.
Our study estimates the prevalence of active and latent TB and identifies risk factors associated
with TB in a cohort of individuals living with HIV in Ontario. Cases diagnosed with HIV during
2001 to 2009 were extracted from the Ontario HIV Treatment Network Cohort Study (OCS).
Reviewing Mantoux test results, diagnoses and medication history, identified active and latent
TB cases. Period prevalence was estimated by proportion with TB and multivariate analyses
were performed to identify associated factors.
One thousand two hundred and ninety-three cases (1293) met our selection criteria. Three
hundred and eighty four (384; 29.7%) were 29 years or younger, 805 (62.3%) aged between 30
years and 50 years and 104 (8.0%) aged 50 years or older. One thousand and nine (1009; 78.0%)
were males. Four hundred and sixty six (466; 36.0%) had at least one record of a Mantoux skin
test. The prevalence of active TB was 76/1293 = 0.0587 or 5.87% (95% CI 4.6% to 7.0%)
whereas the prevalence of latent TB varied from 5.26% (68/1293 = 0.0526) 95% (CI 4.0% -
6.5%) to 11.37% (53/466 = 0.1137) 95% CI (8.2% to 13.7%) depending on the methodology.
In the multivariate analysis, factors associated with active TB were age and birthplace.
Individuals 50 years and older were more likely to have active TB than individuals 30 years and
younger (OR 4.3 CI (1.7-12.7), p <0.01). Individuals born in Africa were more likely to have
active TB than Canadian born (OR 14; 95% CI (5.9 – 32.8) p < 0.001). Factors associated with
latent TB were sex and birthplace. Females were more likely to have latent TB than males (OR
2.4; 95% CI (1.1 – 5.2) p < 0.05). Individuals born in Africa were more likely to have latent TB
than Canadian born (OR 12.3; 95% CI (4.7 – 32.1) p < 0.001).
TB remains a major problem in persons infected with HIV with rates disproportionally high
among the foreign born population. Low rates of Mantoux tests in OCS present a missed
opportunity for active TB prevention among individuals with HIV. To identify individuals with
higher risk of having TB after HIV diagnosis, better screening tools to identify latent TB are
needed. Consideration should be given to data capture systems that would ideally be linked
between Public Health and HIV clinics.


title: Kill switch design pattern for microservice architectures on internet of things devices

contributor:
Liscano, Ramiro
Azim, Akramul

subject:
Microservice architecture
Internet of things
Design patterns
Containers

abstract: Containers and virtual machines are being adopted to develop embedded Linux Internet-of-Things applications. Consumer Internet-of-Things devices have been notoriously insecure due to loss of continued software support. To help prevent this, we propose the ‘kill switch’ pattern. By defining operation levels for microservice-based virtualized application components and their respective communication paths, application functionality can be dynamically modified to an essential state. This thesis contributes: a formalized definition of the proposed design pattern for virtualized microservice applications; and an algorithm for handling the operation level mode change. We illustrate with three example realizations: a generic microservice-based model-view-controller application, an example system utilizing the Suricata intrusion detection system to generate events, and a modified Docker Engine implementation. Use cases, scenarios, and general application design processes are discussed, with suggested areas of future work.


title: Finding success in life: the voices of at-risk youth

subject:
Success
Markers of success
At-risk youth
Youth voice
Life course theory

abstract: The aim of this dissertation is to rethink and broaden the understanding of success from the perspectives of at-risk youth. Current conceptualizations of success commonly found in criminological literature are based on life course, middle-class standards of success, are problematic and marginalizing in nature, and lack youth voice. This study investigates the need for a more diverse theoretical framework for explaining the complex concept of success with the inclusion of youth perspectives. I attempt to answer how at-risk youth construct and characterize their own success and how SNAP Boys – Youth Leadership Services (a community-based program) helps youth achieve their ideas of success. Using in-depth, qualitative interviews and a visual mapping exercise, I show that youth express subjective, non-traditional ideas and experiences of success that move beyond only traditional, well-accepted ideas and markers of success. Youth in this study expressed a combination of traditional and non-traditional ideas and experiences of success and attributed some of their success to participation in SNAP Boys – Youth Leadership Services. This study contributes to criminological literature by offering a theoretical framework for understanding non-traditional, subjective ideas of success as valuable and important, especially for at-risk youth. Importantly, the significance and further contributions of this research are that it enables youth to express their unbounded ideas and experiences of success, highlights the complexity of the concept of success, and challenges criminologists and other stakeholders to push the conversation of success forward through consideration of alternative, individualized ideas of success that represent complex social identities and contexts.


title: Characterization of PVA-Borax-fructose gel for the capture of radioactive wastes generated during nuclear decommissioning activities

subject:
Nuclear decommissioning
Polymer gels
Crosslinking
Polyvinyl-Alcohol
Borax

abstract: With the long-term objective of using polymer gels for the capture of solid, liquid and gaseous waste generated from decommissioning works, characterization of gel properties as well as the properties of the individual constituents of polymer gels has been completed. Characteristics of constituents were investigated over varied concentrations and environments. Preliminary thermal degradation characterization found no adverse hysteresis behaviour regarding the polymer constituent. Constituent chemistry as well as chemistry that enables crosslinking between constituents was examined, and the theory that most accurately describes the crosslinking of constituents was established. Understanding of chemistry and characterization results were employed to successfully manufacture varied gels, with varied applications. Variation of gels were achieved via adjustments, primarily to polymer concentrations.


title: Development and analysis of solar energy based multigeneration systems

subject:
Multigeneration system
Renewable energy
Solar energy
Wind energy
Exergy analysis

abstract: In this thesis three novel multigeneration energy systems are introduced based on renewable resources such as solar and wind energy. The results of the analyses show that, System 1 has a maximum energy efficiency of 43% and a maximum exergy efficiency of 65%, based on the produced maximum power of 48 kW which results in a CO2 reduction of 1613 tons per year which a minimum cost of $236,024 using renewable energy as a source. System 2 has a maximum energy efficiency of 36% and a maximum exergy efficiency of 44% while producing a maximum power of 116 kW and reducing 4873 tons of CO2 per year at a minimum cost of $160,596. System 3 has a maximum energy efficiency of 4 7%, a maximum exergy efficiency of 88%, a 164 kW maximum power production and a CO2 reduction of 2897 tons per year at a cost of $133,021.


title: Li-ion battery electrode state of charge and degradation monitoring using battery casing as the reference electrode

subject:
Three-electrode battery
Degradation analysis
Electrode SOC estimation
Electrode capacity
Unknown input observer

abstract: Lithium-ion battery (LIB) internal state such as state of charge (SOC), electrode capacity, and available lithium-ion monitoring is helpful for effective battery degradation monitoring. Monitoring these internal parameters is challenging due to the weak observability of the electrode parameters and lack of information about available lithium-ion contents in the cell. A reference electrode can be useful to measure the electrode potentials, which can provide information about the internal states, SOC, electrode capacity, and the available lithium-ions in the cell. In this thesis, we proposed a novel three-electrode battery setup approach using battery casing for electrode parameter estimation and degradation monitoring. The presented work introduces a curve matching algorithm to estimate electrode capacity, SOC, and available lithium-ion in the cell and an unknown input observer to estimate anode SOC and capacity. Further, electrode and cell degradation are analyzed by comparing the capacity. The proposed reference electrode setup has less impact on cell degradation compared to the existing reference electrode setup methods. In contrast, the proposed method is practically feasible regarding the practical application of three-electrode batteries for electrode level parameter estimation and available lithium-ion monitoring in the cell.


title: Analytical and experimental study of the effect of cutting tool microgeometry on the impact resistance of milling tools

subject:
Milling
Indexable cutters
Edge radius
Impact resistance
Force model

abstract: This thesis conducted a two-part investigation into the ability of a milling tool cutting insert to resist the impacts that occur during the milling process, with respect to the cutting edge microgeometry. The first part of this thesis contains a mathematical model that was used to predict the cutting forces acting on the tool during milling, accounting for the edge radius. The second part reports the findings of a series of milling tests that were performed, both to verify the mathematical model and to track the wear and failure of the various milling inserts. Five different edge radii were tested and compared. It was found that altering the edge geometry of the tool does affect the cutting forces, wear behaviour, and impact resistance of the cutting inserts, with an edge radius of 35 μm proving to be the optimum choice.