title: Decision Making in Manufacturing Systems: An Integrated Throughput, Quality and Maintenance Model Using HMM

contributor:
Elbestawi, Mohamed A.
Veldhuis, Stephen C.
Mechanical Engineering

subject: machine, data, system, throughput, quality, maintenance data, logical, Hidden Markov Model(HMM)

abstract:
The decision making processes in today's manufacturing systems represent very complex and challenging tasks. The desired flexibility in terms of the functionality of a machine adds more components to the machine. The real time monitoring and reporting generates large streams of data. However the intelligent and real time processing of this large collection of system data is at the core of the manufacturing decision support tools.

This thesis outlines the use of Frequent Episodes in Event Sequences and Hidden Markov Modeling of throughput, quality and maintenance data to model the deterioration of performance in the components that make up the manufacturing system. The thesis also introduces the concept of decision points and outlines how to integrate the total cost function in a business model.

This thesis deals with the following three topics:

First, the component-based data structure of the manufacturing system is outlined especially throughput, quality and maintenance data. In this approach, the manufacturing system is considered as a group of components that interact with each other and with raw materials to produce the manufactured product. This interaction creates a considerable amount of data which can be associated with the relevant components of the system. The relations between the manufacturing components are established on a physical and logical basis. The components properties are clearly defined in database tables specifically created for this application. The thesis also discusses the web services in manufacturing systems and the portable technologies used in plant decision support tools.

Second, the thesis presents a novel application of Frequent Episodes in Event Sequences to identify patterns in the deterioration of performance in a component using frequent episodes of operational failures, quality failures and maintenance activities. A Hidden Markov Model (HMM) is used to model each deterioration episode to estimate the states of performance and the transition rates between the states. The thesis compares the results generated by this model to other existing models of component performance deterioration while emphasizing the benefits ofthe proposed model through the use of the plant data.

Finally the thesis presents a methodology usmg HMM probability distributions and Bayesian Decision theory framework to provide a set of decisions and recommendations under the condition of data uncertainty. The results of this analysis are then integrated in the plant maintenance business model.

It is worthwhile mentioning that to develop the techniques and validate the results in this research; a Manufacturing Execution System (MES) was developed to operate in an automotive engine plant. All the data and results in this research are based on the plant data. The MES which was developed in this research provided significant benefits in the plant and was adapted by many other GM plants around the world.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: An Examination of Two Control Processes That Operate Online During Target Directed Reaching

contributor:
Elliott, Digby
Kinesiology

subject:
online movement control
initial impulse control
target directed reaches
perturbations
visual information processing

abstract:
Examination of goal-directed aiming tasks has revealed that rapid, discrete human action
is amendable to online control. This control affords humans a margin of error in movement
planning and execution as well as a means of acquiring their goals when the body and/or the
environment are extrinsically perturbed. For over a century, the models of online movement
control that have best described the trajectories and outcomes of goal-directed reaches hold that these movements are composed of two distinct components. The first component moves the limb from its resting position towards the target. The second component is a corrective movement that is formed on the basis of a visual referencing of the moving limb and target positions. As such, the temporal and spatial characteristics of these discrete movement changes have been attributed to the limits of visual information processing. Furthermore, the absence of any discrete movement changes in the portions of movements outside of the temporal and spatial limits of vision led many investigators to conclude that first component impulses are ballistic and uncontrollable. However, recent studies involving environmental perturbation and within-subject trial-to-trial spatial variability analyses have evidenced that initial impulses are privy to online control. Because the corrections made early in movement impulses occur quicker than purely afferent visual information can be processed this form of control has been attributed to the use of forward anticipatory processes. The four studies presented here examine the nature of initial impulse control through kinematic analyses of reaches made to targets against various combinations of limb, target, and environment perturbations. This was done in order to evaluate anticipatory control's relationship with visually-regulated control and the relative influence the two processes have on the movement trajectory and performance outcome. The first study examined target-directed reaches made against illusory moving background and target relocation perturbations. The results showed the presence of early anticipatory and late visually-regulated control. Non-interactive main effects of the two perturbations on outcome accuracy revealed that the processes operate independently. The second study tested the applicability of an air discharging stylus as a tool for perturbing reach velocities. The results showed that the stylus effectively perturbed limb velocity and highlighted the presence of a limb forwarding response to either an advancing or hindering perturbation. The findings evidence the non-specific nature of anticipatory control responses. The third study examined reaches made against combinations of actual limb velocity and target position perturbations. The interactive effect of the two perturbations on reach trajectories and outcome accuracy indicated that the perturbations were salient enough to prompt parallel operation of the two control processes. Again, the control of initial movement portions was highlighted by non-specific responses to the perturbations.
The fourth study examined reaches made against combinations of illusory and actual
perturbations to both the anticipatory and visually-regulated control processes. Interestingly,
performers withheld responses to the illusory perturbation unless they were also responding to an actual perturbation. This finding suggests that anticipatory control responses are biased during movement preparation. Furthermore, combined illusory and actual perturbations to target position had interactive effects on visually regulated control. Overall, the studies evidence that target-directed movements are mediated by two modes of control. There is an anticipatory mode of control that operates continuously and, given that reaches are made within the spatial and temporal limits of visual processing, there is also a feedback driven discrete mode of control that overlaps with the continuous mode.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: In Vivo and In Vitro Application of Elastin-Like Polypetides

contributor:
Filipe, Carlos
Chemical Engineering

rights: An error occurred getting the license - uri.

subject:
elastin-like polypeptides
protein biopolymers
aqueous multi-phase system
reversible inverse phase transition
recombinant proteins

abstract:
Elastin-like polypeptides (ELP) are artificially designed protein biopolymers that can be produced by living organisms. These proteins have the unique ability to undergo reversible inverse phase transition, in response to changes in temperature and/or addition of chaotropic salts. Below the transition temperature (T1) , ELP is soluble in water. Increasing the temperature above Ti, ELP coacervates into an aqeous ELP-rich phase. In this thesis, this unique feature of ELP was used in for recombinant protein purification and for the formation of aqueous multiple-phase systems. For protein purification, ELP was fused with an intein and a model protein (thioredoxin), to demonstrate a simple and inexpensive approach for recombinant protein purification. The ELP tags replace the chromatographic media and the intein replaces the use of the protease in conventional methods. Using ELP tags was found to be consistent with large -scale recombinant protein production/purification by purifying an ELP tagged protein using a stirred cell equipped with a microfiltration membrane. When the
temperature and/or salt concer.tration is increased for mixtures containing free ELP and
ELP tagged proteins, simultaneous phase transition takes place. This served as the basis
for the development of a method suitable for selectively recovering molecules from complex mixtures with high specificity, full reversibility, and virtually unlimited affinity. The second parts of this thesis focus on the ability of ELP to form aqueous twophase systems (A TPS) in vitro and most importantly, in vivo- with the formation of aqueous microcompartments in living cells. These compartments exclude the protein making machinery of the cell, acting as depots for newly expressed protein. It is also shown (in vitro) that ELP bastd droplets exclude proteases, protecting proteins from degradation. These observations are important for high-level production of recombinant proteins. Also described, is the formation of protein based aqueous multiphasic systems, with tunable morphologies.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Stochastic Differential Equation Theory Applied to the Modeling of Wireless Channels

contributor:
Field, Tim
Haykin, Simon
Electrical Engineering

subject:
wireless communication
rate of transmission
power consumption
channel model
time-varying stationary channel
state-space channel

abstract:
Ever faster data transmission in wireless communication is desired to satisfy emerging markets for various media services, such as voice, picture and video calls, multimedia messaging, music and video downloads, and even television. With the explosive increase in the use of mobile devices such as cellular phones, PDAs, GPS, and laptop computers, power consumption has become a prime consideration in the design of mobile communication systems. In order to reliably maintain a high rate of transmission and low power consumption, it is imperative that the receiver obtains as much knowledge as possible about the current state of the channel. A more accurate model of wireless communication
channels will indisputably help in obtaining more knowledge about the transient channel state, providing a more accurate and efficient reproduction of the transmitted signal, and decreased power consumption by the receiver. With careful choice and consideration of the channel model, systemic optimization based on the selected channel model will improve the system performance of the transmitter and receiver through better encoding and decoding, as well as through better control of transmitted signal's power level. This thesis focuses
on understanding the physical and statistical characteristics of wireless channels, and investigates how to represent wireless channels using simple mathematical models. This thesis initially studied a simple time-varying stationary channel, i.e.a multipath fiat fading channel without terminal motion, which is typically used for indoor wireless communication. With an introduction of stochastic differential equations, we derived a first-order AR stochastic process to represent this stationary channel. For a general multipath fiat fading channel with terminal motion, the traditional Clarke's model was then extended by incorporating the effects of fluctuations in the component phases and analyzed statistically. The resulting theoretical power spectrum was shown to fit practical measured spectra, in contrast to the traditional theoretical fiat fading channel spectra (Jakes' spectrum in [19]) .
Finally, we developed a state-space model that represents a wireless channel using these modified spectral characteristics. This was achieved by developing a relationship between the state-space model and the theory of a rational transfer function. A novel method for designing a rational transfer function for linear systems was then proposed. In this method, the rational transfer function is represented via the Observable Canonical Form (OCF) to obtain the state-space model, which can be used to represent and simulate a fiat fading wireless channel. The presented state-space approach is simple and provides rapid computation. The present AR and state-space models provide valuable contributions that can be integrated with other algorithms for better system optimization of wireless communication networks.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Unravelling Nested Institutional Arrangements

contributor:
Sproule-Jones, M.
Political Science

subject:
common pool resources
nested institutional arrangements
groundwater policy changes
public policy
institutional innovation

abstract: Common pool resources (CPRs) are noted for their excludability and subtractability issues and early academic commentary stressed that due to the resources' complexity and uncertainty, management efforts were futile and a "tragedy of the commons" was the end result. Recent academic commentary has challenged this end result and has elaborated institutional design principles to sustainably manage CPRs which include the need for nested institutional arrangements (NIAs). However, little is known about how to move between the two extremes, that is, how we change public policy in a move towards and the sorts of institutional innovations that lead us to greater sustainability. This research begins to unravel nested institutional arrangements. It develops a framework for what constitutes a nested institutional arrangement and measures their effect on groundwater policy changes (frequency, type, magnitude) under different conditions of uncertainty as applied to a comparative case study between the Great Lakes Basin (high uncertainty; Ontario, New York) and the Ogallala Aquifer in the U.S. Midwest (low uncertainty; Nebraska). This dimensional mapping reveals the centrality of the nature of the linkages between governance units (especially linkage functionality), linkage complementarity and the effects of diffuse authority structures. In short, it is possible to unravel what an NIA is from the various strands in the literature and to develop linkages between NIAs and outcomes for particular situations (e.g. high vs. low uncertainty areas) in relation to common pool resources (e.g. groundwater). The results provide theoretical guidance for the study of groundwater policy changes by staking out the broad parameters of a strategy for groundwater policy change.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A phylogenetic model to predict the patterns of presence and absence of genes in bacterial genomes and estimate the frequency of horizontal gene transfer

contributor:
Higgs, Paul
Physics and Astronomy

abstract:
For a group of bacterial genomes, the core genome is the set of genes present in all the individual genomes and the pangenome is the set of genes present in at least one of the genomes. Typically, a relatively small fraction of genes is in the core, and many other genes are only found in only one or a small number of genomes. This indicates that there is a wide range of time scales of genome evolution, with rapid insertion and deletion of some genes and long-term retention of others. Here, we study the full set of the genes in a group of 40 complete genomes of Cyanobacteria. Genes are clustered using sequence similarity measures, and for each cluster we obtain the pattern of presence and absence of the genes across the 40 species. We use evolutionary models of gene insertion and deletion to calculate the likelihood of each of the observed patterns. One important case we consider is the infinitely many genes model (IMG) in which each gene can only originate once but can be deleted multiple times. In contrast, the finitely many genes model (FMG) allows more than one insertion of the same type of gene in different genomes, which would be the case if there were horizontal gene transfer (HGT).
The maximum likelihood model allows us to predict which genes have a presence-absence pattern that is best explained by horizontal transfer. We find that about 15% of the genes experienced HGT in their history of evolution. It is found that there is a broad range of rates of insertion and deletion of genes, which explains why there are a large number of genes that follow a typical treelike pattern of vertical inheritance, despite the presence of a significant minority of genes that undergo HGT. We also estimate the
IV
ancestral genome size of Cyanobacteria. It is found that that the inferred frequency of HGT and the size of the ancestral genome both depend on the ratio of insertion to deletion rates of genes. However, the variation in the estimated ancestral genome size is much less than in previous treatments that used parsimony.
As the phylogenetic tree of Cyanobacteria is not completely specified, we test our models on ten different trial species trees that differ by small rearrangements of species. It is found that the estimated frequency of HGT and the maximum likelihood values of the insertion and deletion rate parameters are not very sensitive to small changes in the tree. However, the likelihood of the gene presence/absence patterns on different trees differs significantly among the trees. Therefore, these patterns can be used for phylogenetic inference. This kind of phylogenetic inference makes use of all the genes present on the genomes. In contrast, phylogenetic methods using protein sequence evolution only make use of the relatively small number of genes that are present in all of the genomes in the set. We compare the likelihood ranking of trial trees using the presence/absence data with the ranking of the same trees using protein sequence evolution with conserved common genes (present in all cyanobacteria and a large proportion of other genomes) and signature genes (present in all cyanobacteria and no other species).

abstract: Thesis

abstract: Master of Science (MSc)


title: Can High Performance Work Systems Transfer Organizational Citizenship Behavior from A Discretionary to A Sustainable Advantage? The Questions of How, Why, and When

contributor:
Baba, Vishwanath
Business

subject: High Performance Work Systems

subject: Organizational Citizenship Behavior

subject: Organizational Citizenship Behavior Role Definition

subject: Trust in Supervisor

abstract:
One issue that has been neglected and is gaining currency in the organizational citizenship behavior (OCB) literature is the extent to which individuals consider OCB to be part of the job (OCB role definition). A recent meta-analytic review reveals that employees are more likely to perform OCB when they define OCB as in-role rather than as extra-role. However, little attention has been paid to the influences of organizational practices on employee OCB role definition. This neglect is of particular relevance because researchers have argued that how employees view their role obligations are likely to be subject to some purposeful organizational practices. Thus, this paper focuses on the effects of high-performance work systems (HPWS) on employee OCB role definition.
This paper adopts multiple theoretical perspectives (e.g., social exchange, organizational identification, ability-motivation-opportunity, and trust) to understand how, why, and when HPWS cause employees to expand their job requirements to include OCBs like helping and voice. Using a multisource data collected at 4 waves from 208 supervisor-employee dyads in Taiwan, I examined the following: (a) the direct effect of employee-experienced HPWS on employee helping and voice role definitions, (b) the mediating roles of employee helping and voice role definitions in the employee-experienced HPWS and actual employee helping and voice relationships, (c) the mediating roles of employee social exchange and organizational identification perceptions toward the organization, as well as employee efficacy, instrumentality, and autonomy perceptions toward helping and voice in the relationships between employee-experienced HPWS and OCB role definitions, (d) the direct effect of employee trust in supervisor on employee helping and voice role definitions, and (e) the moderating role of employee trust in supervisor in the relationships between employee-experienced HPWS and employee helping and voice role definitions. The results confirm the direct effects of employee-experienced HPWS and trust in supervisor, the mediating effects of employee helping and voice role definition, and employee efficacy, instrumentality, and autonomy perceptions toward helping and voice, as well as the moderating effects of employee trust in supervisor, such that employee trust in supervisor strengthened the effects of employee-experienced HPWS on employee helping and voice role definitions when trust in supervisor was high than when it was low. Implications for research and practice are discussed.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: ELLIPSOMETRY AS A PROBE OF THIN COPOLYMER FILMS: CRYSTALLISATION & MORPHLOGY

contributor:
Dalnoki-Veress, K.
Science

subject: ellipsometry, polarisation, crystallisation, morphological transition, differential scanning calorimetry, refractive index

abstract: This study presents results on the use of ellipsometry as a novel probe for thin films of a diblock copolymer. Ellipsometry makes use of the change in polarisation induced upon reflection of light from a film covered substrate to enable calculation of the refractive index and thickness of the film. The infom1ation obtained in these measurements can be compared to differential scanning calorimetry, with the additional advantages that small sample volumes and slow cooling rates can be employed, and expansion coefficients can be determined. The work is presented in two parts; first crystallisation within the phase-separated domains is studied, then a morphological transition in the diblock ordering is characterised. By studying the temperature dependence of the film thickness and refractive index, crystallisation kinetics within very small volumes( 10^-10 L) of a poly (butadiene-b-ethylene oxide) diblock copolymer are measured. Through a comparison of two different PEO block lengths, a reduction in both the crystallisation and melting temperatures is demonstrated as the domain volume is decreased. Upon cooling, an additional transition is observed. We ascribe this to a morphological transition from a layer of ordered spheres to a lamellar layer at the substrate, which is consistent with a comparison between the data and simulated ellipsometry data. The sensitivity of ellipsometry makes it a well suited and versatile technique for probing thin film kinetics in diblock copolymers.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Fluorescence of PDT Photosensitizers for Quantitative Cancer Diagnosis and Treatment Monitoring

contributor:
Fang, Qiyin
Biomedical Engineering

subject:
Fluorescence
Photodynamic therapy

abstract:
Photodynamic therapy (PDT) has been considered a favorable approach in
certain oncology applications for its little invasiveness and better targeting
specificity compared to conventional therapies. In PDT, localized photosensitizers
can be activated by light to produce cytotoxic oxygen species. However, the
prescribed drug and light doses do not provide satisfying outcomes as the PDT
efficacy relies strongly on the interplay between localized dose factors. Therefore,
the fluorescence emission from active photosensitizers has been investigated
extensively for real-time PDT dosimetry.
This dissertation focuses on characterizing fluorescence properties of two
photosensitizers, Photofrin® and PpIX, in cellular models and discusses about their
potential clinical applications. First, we introduc time-resolve fluorescence (TRF)
of photosensitizers as a potential tool in PDT dosimetry. TRF acquires fluorescence
decay profiles and it is sensitive to drug-microenvironment interactions that occur
frequently in PDT. Therefore, it provides complementary information in addition to
fluorescence spectra that could be subject to intensity artifacts. In this dissertation,
we review TRF studies on PDT photosensitizers, and quantify TRF parameters of
Photofrin® at various subcellular locations. Moreover, analytical solutions are
developed to correct distorted TRF measurements from commonly used
time-domain data acquisition.
Second, we report a new concept – integrated detection and treatment of
Barrett’s Esophagus (BE). BE is a pre-cancerous lesion considered as a major risk
factor in developing esophageal cancers. However, early intervention of BE has
remained a challenging issue as tissue biopsy introduces significant sampling errors
and the separate procedures between diagnosis and treatment add relocation errors.
We proposed to use PpIX fluorescence to highlight morphological features at the
cellular level for quantitative classification, followed by well-characterized
treatment. Current proof-of-concept studies were performed separately, whilst the
detection and treatment can be integrated using confocal endomicroscopy
technology. Overall, these studies examine the potential benefits provided by
fluorescence of photosensitizers for cancer diagnosis and treatment monitoring.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Sensor Management and Information Flow Control for Multisensor Multitarget Tracking and Data Fusion

contributor:
Kirubarajan, T.
Electrical and Computer Engineering

subject:
sensor management
unmanned aerial vehicles
multitarget tracking

abstract:
 In this thesis, we address the problem of sensor management with particular application to using unmanned aerial vehicles (U AV s) for multi target tracking. Also, we present a decision based approach for controlling information flow in decentralized multi-target multi-sensor data fusion.

 Considering the problem of sensor management for multitarget tracking, we study the problem of decision based control of a group of UAVs carrying out surveillance over a region that includes a number of moving targets. The objective is to maximize the information obtained and to track as many targets as possible with the maximum possible accuracy. Uncertainty in the information obtained by each UAV regarding the location of the ground targets are addressed in the problem formulation. We propose an altered version of a classical Value Iteration algorithm, one of the most commonly used techniques to calculate the optimal policy for Markov Decision Processes (MDPs) based on Dynamic Element Matching (DEM) algorithms. DEM algorithms, widely used for reducing harmonic distortion in Digital-to-Analog converters, are used as a core element in the modified algorithm. We introduce and demonstrate a number of new performance metrics, to verify the effectiveness of an MDP policy, especially useful for quantifying the impact of the modified DEM-based Value Iteration algorithm on an MDP policy. Also, we introduce a multi-level hierarchy of MDPs controlling each of the UAV s. Each level in the hierarchy solves a problem at a different level of abstraction. Simulation results are presented on a representative multisensor-multitarget tracking problem showing a significant improvement in performance compared to the classical algorithm. The proposed method demonstrated robust performance while guaranteeing polynomial computational complexity.

 Decentralized multisensor-multitarget tracking has numerous advantages over singlesensor
or single-platform tracking. In this thesis, we present a solution for one of the main problems in decentralized tracking, namely, distributed information transfer and fusion among the participating platforms. We present a decision mechanism for collaborative distributed data fusion that provides each platform with the required data for the fusion process while substantially reducing redundancy in the information flow in the overall system. We consider a distributed data fusion system consisting of platforms that are decentralized, heterogenous, and potentially unreliable. The proposed approach, which is based on Markov Decision Processes with introduced hierarchial structure will control the information exchange and data fusion process. The information based objective function is based on the Posterior Cramer-Rao lower bound and constitutes the basis of a reward structure for Markov decision processes which are used, together with decentralized lookup substrate, to control the data fusion process. We analyze three distributed data fusion algorithms - associated measurement fusion, tracklet fusion and track-to-track fusion. The thesis also provides a detailed analysis of communication and computational load in distributed tracking algorithms. Simulation examples demonstrate the operation and the performance results of the system.

 In this thesis, we also present the development of a multisensor-multitarget tracking testbed for simulating large-scale distributed scenarios, capable of handling multiple, heterogeneous sensors, targets and data fusion methods
.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Urban/Rural Differences and the Culture War in the United States and Canada

contributor:
Fox, John
McLaughlin, Neil
Sociology

subject: elections, United States, Canada, urban/rural, culture war,

abstract: Recent national elections in the United States and Canada reveal an urban/rural cleavage in vote choice. This cleavage has been overshadowed by the red state/blue state analysis in the United States and dismissed as an artifact of demographic and regional differences in Canada; however, this voting gap appears to have emerged with the increasing salience of "culture war" issues in North American politics. Sociological theory suggests that there may be an affinity between urban and rural place of residence and the progressivist and traditionalist poles of the culture war which may explain urban/rural differences in vote choice. In the present study, urban/rural voting differences are assessed using election surveys from the Canadian Federal and United States Presidential Elections of 2004 and using aggregate data from Canadian Federal and United States Presidential Elections since 1920. The results show that the urban/rural gap has grown to its widest point in recent elections in both countries, coinciding with the reorganization of the right wing of Canadian party politics and the domination of the Republican Party by social conservatives in the United States. After controlling for demographic and social characteristics, rural residents are found to be on average more socially and morally traditional than urban residents. Individual attitudes on gay marriage, abortion and gun control contributed to the urban/rural voting differences observed in both countries. It is concluded that the high profile of moral and social issues associated with the culture war has led to the manifestation of urban/rural cultural differences as a political cleavage in recent Canadian and American national elections.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: High-Quality Screening of Pharmacological Chaperones for Enzyme Enhancement Therapy

contributor:
Britz-McKibbin, Philip
Chemical Biology

subject: Pharamacological Chaperones, Genetic Disorders

abstract: Enzyme enhancement therapy based on pharmacological chaperones (PCs) represents a promising new therapeutic strategy for the treatment of rare genetic disorders associated with protein misfolding. PCs are small extrinsic molecules that activate, stabilize and promote folding as a way to rescue mutant enzymes from endoplasmic reticulum-associated protein degradation. To date, high throughput drug screening has relied on fluorescence-based inhibition and/or thermal stability assays for putative PC selection from large chemical libraries with confirmatory testing on patient-derived cell-based assays or animal models. However, conventional primary screening methods do not directly measure for chaperone activity that may contribute to high attrition rates in drug discovery. The major aim of this thesis is to develop and validate a high quality screening strategy for the discovery of novel PCs that restore the activity of denatured/mutant enzymes associated with Gaucher disease (GD) and phenylketonuria (PKU). Chapter II introduces a simple yet selective capillary electrophoresis (CE)-based inhibition assay for improved characterization of previously-approved FDA drugs that function as putative PCs for β-glucocerebrosidase (GCase), a lysosomal enzyme associated with GD. A novel in-vitro assay based on restoration of enzyme activity via denaturation (READ) was developed in Chapter III for unambiguous characterization of the chaperone activity of previously identified PCs for GCase when using CE with UV detection. Chapter IV subsequently adapted READ to a fluorescence-based high throughput screening platform to discover novel stilbene derivatives as PCs from a chemical library comprising structural unique compounds after in silico assessment of drug-like activity. Chapter V then used this two-tiered screening strategy to discover plant-derived natural products that enhance the activity of phenylalanine hydroxylase (PAH), the enzyme associated with PKU. In summary, an integrated two-tiered strategy for high quality screening of PCs has been developed in this thesis, which is anticipated to enhance drug discovery while reducing false discoveries for treatment of various human diseases associated with deleterious protein misfolding.

abstract: Thesis

abstract: Candidate in Philosophy


title: Sperm Competition in Fish

contributor:
Balshine, Sigal
Wood, Chris M.
Biology

subject:
sperm competition
males
fertilization
sperm traits

abstract: Sperm competition, the contest between sperm from rival males for fertilizations, is an important evolutionary force shaping sperm characteristics. Theory predicts that males experiencing elevated levels of sperm competition will invest more in sperm number, size and speed. While broad support exists for the idea that elevations in sperm competition lead to increased investment in sperm production, there is mixed support for the role of sperm competition in shaping sperm size and swimming speed. In this thesis, using a combination of within-species and comparative studies, I describe how sperm competition has influenced sperm traits in fishes and critically test a number of predictions from sperm competition theory. In the marine plainfin midshipman fish (Porichthys notatus) and the fresh-water shell brooding cichlid Telmatochromis vittatus, I show that the males who experience the highest level of sperm competition had faster but not longer sperm. Instead, selection appears to have acted on sperm energetics, increasing energy production to drive sperm movement in males who experience more intense levels of sperm competition. In a comparative study using Tanganyikan cichlids, I show that males in species experiencing high levels of sperm competition (i.e. promiscuous species) had both longer and faster sperm than males of closely related species unlikely to experience sperm competition (i.e. monogamous species). I also uncovered a predicted but previously inadequately tested relationship between sperm size and speed. This relationship holds across, but not within, species and I discuss possible explanations for differences between and within species. Finally, I used directional tests of trait evolution to assess how selection acts to increase sperm swimming speed and provide evidence that the evolution of fast swimming sperm preceded the evolution of long sperm across cichlid fishes. Together, the results of this thesis show that spenn competition promotes the evolution of faster swimming spenn in fishes and highlights the importance of sperm energetics in detennining the competitive success of ejaculates.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Acute Responses and Chronic Adaptations of the Arterial System to Sprint Exercise and Training

contributor:
MacDonald, Maureen J.
Gibala, Martin J.
McCartney, Neil
Kinesiology

subject: acute, chronic (training), exercise, sprint, oxygen, blood flow, pressure,

abstract:
The present thesis examined the acute and chronic (training) hemodynamic
responses to the unique exercise stimulus of high-intensity "sprint" interval exercise or
training (SIT). Previous research has characterized the muscle metabolic and exercise
performance adaptations to both short and medium term SIT, however the cardiovascular
adjustments and adaptations have not been examined. As part of this thesis two studies
were designed to permit evaluations of the chronic cardiovascular responses to a six-week
SIT intervention protocol, while two separate studies examined the acute impact of
a sprint exercise session on indices of vascular structure and function. Comparisons were
made between the SIT and traditional endurance exercise training (ET) in the two
exercise training studies, while comparisons were made between a single sprint and that
of multiple sprints in the acute exercise studies. The subject population examined in this
research was young healthy participants.

Our general hypothesis regarding the training adaptations was that similar
changes of artery stiffness, vascular endothelial function, blood flow kinetics and oxygen
uptake kinetics would occur following SIT compared to ET. Regarding the acute effects
of a sprint exercise, we expected arterial stiffness to decrease in the exercising limbs and
increase in the central arteries, similar to the responses observed previously immediately
following endurance exercise, while we hypothesized that endothelial function would be
decreased immediately following the exercise session because of the intense nature of the
exercise. The overarching hypothesis guiding these specific hypothesis is that we believe
that individual bouts of exercise impact on the arterial wall through the generation of a
shear stimulus related to cyclic increases in blood flow and blood pressure. In the short-term the acute response of the artery depends on the composition of the arterial wall and
the local stimulus. Over time, functional and structural adjustments occur to normalize
the impact of shear forces.

Training adaptations in vascular structure and function to SIT were similar to
those observed with ET. Both exercise training methods stimulated improved peripheral
artery stiffness and endothelial function. The rate of increase in oxygen uptake (kinetic
response) was not improved with either training method. However, estimated myocardial
demand was reduced with ET but not SIT, which indicates more favourable adaptation in
central hemodynamics with ET.

Acute sprint exercise markedly reduced peripheral artery stiffness in the exercised
limbs well into recovery (~45 minutes), which may benefit central hemodynamics after
exercise completion. Sprint exercise also acutely decreased endothelial function, likely
because of high oxidative stress generated during the exercise bout and may provide the
ideal stimulus for endothelial adaptation.

In summary, this thesis highlights the chronic and acute effects of sprint interval
exercise and training in young health individuals. The notion that sprint interval exercise
provides equivalent benefits to the cardiovascular system as endurance exercise may be
true in the peripheral circulation. However, further study focusing is required before the
general acceptance of more favorable central hemodynamic effects from endurance
exercise training.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Microstructure and Mechanical Properties of the Fusion and Heat-Affected Zones of a Laser Welded DP780 Steel

contributor:
McDermid, Joesph R.
Materials Science and Engineering

subject: HAZ softening, mechancial characterization, hardness measurements, martensite tempering, dual phase steels, laser welding

abstract:
Bead-on-plate laser welds were made on an industrially produced DP780 steel to determine the effect of normalized welding heat input on the microstructure and mechanical properties within the weld fusion zone (FZ) and heat affected zone (HAZ) with reference to the base material (BM) mechanical properties.  Normalized welding heat input was calculated using an established model from the literature utilizing measurements from the weld cross-section microstructures along with known materials properties.  Microhardness profiles and optical microscopy were employed to evaluate materials properties and microstructural changes across the various microstructural zones of each weld. The mechanical properties of the welds were evaluated globally through standard ASTM tensile specimens as well as through a series of specialized mechanical testing sample geometries which examined the properties of individual microstructural zones. These specialized sample geometries included non-standard uniaxial and plain strain tension where effective stress and effective strains were used to compare the mechanical properties across samples.
It was determined that there was a good correlation between ASTM standard samples and the specialized sample geometries employed in this study and that the UTS and YS values obtained in both cases were comparable.  Sigmoidal decay behaviour was observed in the UTS and YS with increasing heat input for both the FZ and HAZ of all welds.  It was found that welds with heat inputs greater than 60 J/mm2 had both a UTS and YS which were significantly depressed in the FZ and HAZ when compared to the base material values.  Conversely, welds with heat inputs below 36.3 J/mm2 were found to have a UTS and YS in both the FZ and HAZ microstructural zones which were above the values determined for the BM.  When global weld properties were tested, it was found that welds with a heat input greater than 60.0 J/mm2 failed within the HAZ while welds with heat inputs below 36.3 J/mm2 failed within the BM.   It has been shown that there is a significant correlation between the heat inputs of laser welded DP steels and both the mechanical properties and microstructural features of the various microstructural zones as well as the location of failure during weld tensile testing.  It has also been demonstrated that the mechanical properties of weld microstructural zones can be qualitatively evaluated using specialized tensile testing geometries.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Victorian Narratives of Intimate Violence and the Problems of Visibility

contributor:
Kehler, Grace
English

subject: intimate violence, impulse, public, consumable, abuse, domestic

abstract:
This dissertation explores the struggle between the impulse to cover up intimate violence and the impulse to make it public and consumable in nineteenth century England. It shows that intimate violence was both spectacular and unspeakable, rendering woman abuse a highly contested site of representation. It also reveals, however, that these ostensibly diametric modes of portraying violence worked in tandem to test the limits of what was socially and culturally representable during the period, and, in turn, to challenge hierarchies of genre, gender, class, and sexuality.

This thesis is therefore both a study of the ways in which representations of intimate violence have avowed the imagined differences between members of disparate social categories and a study of how these differences often break down in the face of brutality. Chapter One shows that although street literature's representations of abuse seem invested in spectacularizing working-class violence, they often gesture towards the failures of middle-class domestic life and thus presume a unique vision of cross-class, shared moral experience. Chapter Two explores how feminist poet, pamphleteer, and novel writer Caroline Norton conflates multiple female identities to emphasize the importance of women's creative self-imagining as a means to resist physical violence and the rhetoric that encourages or allows it. Reading Anthony Trollope's Barchester Towers, Chapter Three intersects discourses on abuse with disability studies to interrogate how the conspicuous bodies of battered women can disrupt male homosocial interactions and complicate discourse on trauma and representation. Finally, Chapter Four considers the ways in which displacements of intimate violence in Wilkie Collins's The Woman In White create sympathetic bonds that blur subjective distinctions between abusive men and violated women to test male authority over representation.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Associative and Non-Associative Performance Phenomena in Learning Social Contingencies from Rich and Heterogeneous Stimuli

contributor:
Brooks, L. R.
Psychology

subject: human contingency learning (HCL), associative learning, cognitive, heterogeneous, stimuli

abstract:
One of the most central and current debates among those studying human contingency learning (HCL) concerns whether it is best understood as the result of associative learning, a product of higher-order cognitive processes, or some combination thereof. Though the field appears to be moving toward the latter accounts, much of the evidence being generated to evaluate and select among them comes from tasks that typically present only information about the few variables involved in the contingency(s), in the exact same manner on every trial. While effective for examining how the statistical properties of experience affect learning, these procedures do not capture some of the conditions of everyday cognition and are apt to be less effective for engaging non-associative and top-down influences on performance.

The current work introduces a task that involves learning contingencies in others' behavior from descriptions that require the learner to determine the focus of learning, and to deal with both variability in manifestation of the objects of learning and extraneous information. Across several experiments, performance reflects phenomena, including ΔP, outcome density and blocking effects, which have been well established in HCL and are consistent with associative accounts. At the same time, the findings also suggest that (a) domain-specific theories affect the weighting of evidence in contingency perception and the discoverability of contingencies, and (b) outcome predictions, a typical measure in HCL, are influenced by specific instance memory in addition to abstract contingency knowledge. These findings are difficult to reconcile with the data-driven nature of associative views, and join a growing number of demonstrations suggesting that a viable account of HCL must involve higher-order cognitive processes or top-down influences on performance.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CMOS Photodetectors for Low-Light-Level Imaging Applications

contributor:
Deen, M. Jamal
Shahram, Shirani
Electrical and Computer Engineering

subject:
weak optical signals
light detection
CMOS
Active pixel sensor
biomedical diagnosis devices

abstract: Weak optical signals have to be measured in different fields of sciences including chemistry and biology. For example, very low levels of fluorescence emission should be detected from the spots on a DNA microarray that correspond to weakly expressed genes. High sensitivity charge-coupled devices (CCDs) are used in these applications. CCDs require special fabrication and are difficult to integrate with other circuits. CMOS is the technology used for fabrication of CPUs and other widely used digital components. CMOS is not optimized for light detection. CMOS circuits are however cheap, low power and can integrate several components. Active pixel sensor (APS) is the most common pixel structure for CMOS photodetector arrays. In this work we provide an accurate analysis of the APS signal using new models for the capacitance of the photodiode. We also provide a complete noise analysis of the pixel to calculate the SNR of the pixel and provide optimum operation points. We propose a new mode of operation for APS that can achieve at least l 0 dB higher SNR, than conventional APS, at light levels of less than 1 μW/cm^2. We fabricated several APS pixels in CMOS 0.18 μm technology and measured them to confirm the proposed analyzes. There are applications like fluorescence lifetime imaging that require both sensitivity and fast response. Photomultiplier tubes (PMTs) are commonly used in these applications to detect single photons in pico- to nano-seconds regime. PMTs are bulky and require high voltage levels. Avalanche photodiodes (APDs) are the semiconductor equivalent of PMTs. We have fabricated different APDs along with different peripheral circuitries in CMOS 0.18 μm technology. Our APDs have a 5.5 percent peak probability of detection of a photon at an excess bias of 2 V, and a 30 ns dead time, which is less than the previously reported results. The low price of CMOS makes modem diagnosis devices more available. The low power of CMOS leads to battery-driven hand-held imaging solutions, and its high integration leads to miniaturized imaging and diagnosis systems. A low-light-level CMOS imager paves the way for the future generation of biomedical diagnosis solutions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: EXPLORING NOVEL MECHANISMS AND THERAPIES FOR CELIAC DISEASE

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject: Celiac disease

abstract:
The gastrointestinal tract forms the body’s largest interface with the external environment and is exposed to a vast amount of foreign material, including pathogenic and commensal bacteria, as well as food antigens. The gastrointestinal tract has multiple functions that are performed through complex interactions by its different components. It must be able to degrade food, absorb nutrients and eliminate waste, while at the same time maintain a balance between immune tolerance and protection against pathogenic and antigenic material. This concept of mucosally-induced tolerance is a key feature of the gut immune system, whereby a state of local and systemic unresponsiveness to food protein or systemic ignorance of commensal bacteria is maintained under homeostatic conditions through interactions between the host, dietary factors, and the intestinal microbiota. Dysfunctional interactions can lead to a breakdown in tolerance to otherwise innocuous antigens. One of the best characterized food sensitivities is celiac disease (CD). CD is a chronic immune-mediated disease triggered by the ingestion of gluten, the water insoluble protein fraction in wheat, rye and barley, in patients who are HLA/DQ2 or DQ8 positive. Celiac patients can experience a loss of oral tolerance to gluten any time throughout life. The clinical presentation of CD is variable and is often associated with extra-intestinal autoimmune diseases, such as type 1 diabetes (T1D). The increasing incidence of CD and the observation that only a small proportion of genetically susceptible individuals go on to develop active inflammation suggest a role for additional environmental factors in disease pathogenesis. The current treatment for CD is a strict, life-long adherence to a gluten-free diet (GFD), which is very demanding. Frequent gluten contamination can lead to persistent mucosal damage and symptoms, which have a negative effect on quality of life. Understanding the environmental and host factors that contribute to gluten tolerance is critical for the development of adjuvant therapies to the GFD. Therefore, the overall aim of my thesis is to characterize a humanized mouse model of gluten sensitivity in order to study factors that influence host-responses to gluten and to investigate potential therapeutic strategies.
In chapter 3 of this thesis I characterized host responses to gluten using transgenic non-obese diabetic (NOD)/DQ8 mice. I found that gluten sensitization in NOD/DQ8 mice induced barrier dysfunction with a moderate degree of enteropathy and the development of anti-gliadin and anti-tissue-transglutaminase antibodies. I also explored the potential role of gluten in the development of T1D and found that gluten-induced barrier dysfunction was not sufficient to induce insulitis; a partial depletion of regulatory T cells (Tregs) plus gluten sensitization was required. In chapter 4, I utilized this model to demonstrate that the microbiota can modulate host responses to gluten. I found that both the presence and absence of a microbiota, as well as the composition of the microbiota influenced host responses to gluten in NOD/DQ8 mice. Finally, Chapters 5 and 6 of this thesis utilized transgenic DQ8 mice to explore two different adjuvant therapies for CD. In chapter 5, I showed that administration of a gluten binding polymer, P(HEMA-co-SS, to gluten-sensitive HLA/DQ8 mice reduced short-term and long-term gluten-induced barrier dysfunction and inflammation. In chapter 6, I discovered that elafin, a human anti-protease, was decreased in patients with active CD and in vitro, it inhibited the deamidation of gliadin peptides, a key step in the pathogenesis of CD. I showed that administration of elafin prevented gluten-induced barrier dysfunction and intraepithelial lymphocytosis. Together these results, (a) provide an in depth characterization of a humanized animal model for studying gluten-induced intestinal and extra-intestinal immune responses, (b) demonstrate the role of the microbiota as an environmental modulator of gluten-induced immune responses, (c) support the preclinical potential of two novel adjuvant therapies to the GFD. These findings emphasize the translational value of using relevant animal models to study the complex interactions between environmental and host factors that contribute to intestinal health and disease.

abstract: Thesis

abstract: Doctor of Philosophy (Medical Science)


title: Faith's Sublime Traversal: Rhetorical and Dialectical Approaches to Preserving Christianity as Existential Movement

contributor:
Kroeker, P. Travis
Religious Studies

subject:
history of western thought
human agency
Radical Orthodoxy
Kierkegaard
Christianity
love
faith

abstract:
This thesis weighs the merits of "rhetorical" and "dialectical" theological
responses to the history of western thought as a history of objectification. Objectification is theologically relevant insofar as it can be shown to be the root of modern and postmodern "suspicion" of religion. In modernity's predictable temporal economy, the human being is not a true "agent" in history, but the object of a spatialized logic of determining causes. And postmodernism's acute sensitivity to temporality as unpredictable "flux" nonetheless implies that the human being as agent is "sacrificed" at each successive moment to an arbitrary measure of difference. What is ruled out in both cases is the Christian supposition that the true form of creation is not a "thing" but a "way," a way whose temporal articulation may be analogous to the eternal "differentiation" of the Trinitarian God. This diagnosis is derived from the theology of John Milbank and "Radical Orthodoxy," which suggests in addition that only a theological "rhetoric" can safeguard the human being from objectification, in that rhetoric does not tempt the subject to define himself or herself as a "thing," but "persuades" that subject into becoming a self only by living the mysterious movement of caritas. This thesis first of all clarifies the little noticed Kierkegaardian heritage implicit in Radical Orthodoxy's "existential" imperative to rhetoric. But ultimately it argues that
Kierkegaard's account of love, which refuses to appeal to a "hope" that is authenticated by any rhetorical exemplars, more adequately captures the Radical Orthodox imperative to Christianity as an existential way than does any rhetorical appeal. On my reading, Kierkegaard offers an account of love as giving rise to a unique mode of expectancy- a comportment to the future as the possibility of the good-which keeps the subject eternally in motion through faith's inexplicable resolve.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Engineering Nanostructures Using Dissipative Electrochemical Processes

contributor:
Kruse, Peter
Chemistry

subject: ordered patterns at nanoscale

subject: nanostructures

subject: nanoelectronics applications

subject: reaction-diffusion adaptive systems

abstract:
The realm of the nano-world begins when things start getting smaller in size than one thousandth of the thickness of the human hair. Surface patterning at the nanoscale has started to find applications in information storage, self-cleaning of surfaces due to the "lotus effect", biocompatible materials based on surface roughness and many more. Several methods such as particle-beam writing, optical lithography, stamping and various kinds of self-assembly are widely used to serve the purpose of patterning smaller surface structures. However, globally much research is going into developing more efficient, reproducible and simple methods of patterning surfaces and in better controlling the order of these nanostructures. Researchers have always looked upon Nature to get inspiration and to mimic its model in engineering novel architectures. One of the methods used by this greatest artist (Nature) to make beautiful patterns around is through reaction diffusion based non-linear processes. Non-linear systems driven away from equilibrium
sustain pattern only during the continuous dissipation of a regular flow of energy and are different from equilibrium processes that are converging towards a minimum in free energy (a. k. a. self-assembly). Dissipative pattern formation from micrometer to kilometers scale has been known but ordered patterns at nanoscale have never been achieved. In the process of thoroughly characterizing suitable substrates for nanoelectronics applications, we came across a remarkable process leading to the formation of highly
ordered arrays of dimples on tantalum. The pattern formation happens in a narrow electrochemical windows which are functions of many parameters such as concentration, external applied voltage, temperature etc. After investigating the formation of dimples by performing spatio-temporal studies, we found that the underlying principles behind this unique way of engineering nano-structures have their roots in nonlinear interaction/reaction electro-hydrodynamics. We then have demonstrated the generality of this process by extending it to titanium, tungsten and zirconium surfaces. The pattern similar to Rayleigh-Bernard convection cells originates inside the electrochemical solution due to coupling among electrolyte ions during their migration across the electrochemical double layer (Helmholtz layer) and simultaneously imprints on the surface due to dissolution of metal oxide via etching. Based on these results we further postulate that, given appropriate electropolishing chemistry; these patterns can be formed on virtually any metal or semiconductor surface. The application of these nanostructures as nanobeakers for placing metal nanoparticles is also elucidated Highly porous materials such as mesoporous oxides are of technological interest for catalytic, sensing, optical and filtration applications: the mesoporous materials (with pores of size 2-50 nm) in the form of thin films can be used as membranes due large surface area. In the second part of this thesis, a new technique of making detachable ultrathin membranes of transition metal oxides is presented. The underlying concepts behind the detachment of membranes from the underlying substrate surface are discussed. The control on the size of the pores by modulating the voltage and concentration is also
elucidated. The method is generalized by showing the similar detachment behavior on other metal oxide membranes.Thus, the results of this work introduces new techniques of engineering nanostructures on surfaces based on reaction-diffusion adaptive systems and contribute to the better understanding of electrochemical self-organization phenomena due to
migration coupling induced electro-hydrodynamics.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A New Approach to Obtain Forming Limits of Sheet Materials

contributor:
Jain, Mukesh K.
Metzger, Donald R.
Mechanical Engineering

subject:
forming limit diagram determination
localized necking criterion

abstract:
A new methodology is proposed to obtain the forming limit diagram (or FLD) of sheet materials by utilizing routinely obtained experimental load versus displacement traces and incorporating finite element (FE) analysis of strain history to extract the characteristic points of diffuse and localized necking and further the limit strains. The experimental data from hemispherical punch stretching test such as limit dome height, maximum load and location of inflection point are utilized to adjust the load curves in the FE simulations. An optimization procedure to obtain various parameters in material definition has been established to obtain a good agreement between the FE-based and
experimental punch load versus displacement curves. An analysis of FE model based strain history is then carried out to determine the limit strains. This approach avoids using experimental strain measurement in the vicinity of the neck on the dome specimens. The materials tested with the new methodology include automotive sheets AA6111-T4, AA6181-T4 and DP600. The one utilized for optimization of FE inputs was AA6111-T4. The proposed method for FLD determination considers out-of-plane displacement, punch-sheet contact and friction, and avoids the use of a rather arbitrary inhomogeneity factor to trigger localization such as in the Marciniak-Kuczynski method.
A new criterion to determine the localized necking is proposed by seeking an
inflection point m the major strain rate curve, or, maximum point in the second order of derivative of major strain, (ε1)max. The proposed localized necking criterion is compared with other two methods to determine the onset of localized necking. These are (i) Bragard criterion for post-test of deformation, and (ii) critical major strain (ε1)cr based on comparison of strain of material inside the localized site and its vicinity in the un-necked site. The new criterion of (ε1)max exhibits a more definite physical meaning towards developing an understanding of flow localization, formability and fracture. This new approach for obtaining FLDs is rapid and accurate and could be implemented easily for routine FLO generation in a lab setting with little user input and subjectivity.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Long-term Fate and Migration of DDT in Soil and Groundwater at Point Pelee National Park, Ontario, Canada

contributor:
Smith, James E.
Geology

subject:
Point Peele Nation Park
DDT
concentrations
soil

abstract: Last page is titled: Appendix 1: DVD of Model Simulations (See DVD in Back Envelope). There was no DVD present for upload.

abstract: Point Pelee National Park (PPNP), located in Leamington, Ontario, Canada experienced widespread application of DDT from 1950 until DDT was banned in Canada in 1970. vVbile DDT has not been applied at PPNP for over 30 years recent studies have shown that the compounds DDT, ODE and DDD are highly persistent in shallow soils at PPNP and often exceed regulatory guidelines set forth by the Ontario Ministry of the Environment and Environment Canada. Field study combined with numerical modelling was undertaken to assess the concentrations of DDT, DDE and DDD in groundwater and provide insight into the fundamental processes controlling the persistence and migration of DDT within former agricultural areas of PPNP. Results of one-dimensional pesticide fate and transport modelling from 1950 to 2003 using LEACHMP show that within former agricultural areas of PPNP, DDT is transformed primarily  not DOE under aerobic conditions. Within the Camp Henry Orchard (CHO), half lives for the production of DDE are 30 years. LEACHMP modelling showed that adsoption was the most important process limiting DDT leaching to groundwater. The depth to the water table was found to influence DDT concentrations seen at the water table throughout former agricultural areas of PPNP, and DDT is most likely leaching to the water table slowly over time. Two dimensional saturated zone modelling using OW-WETLAND was used to test various loading scenarios based on LEACHMP simulated fluxes across the water table. Model outputs illustrated the bidirectional movement of contaminants toward both the marsh and Lake Erie, depending on the source location relative to the groundwater flow divide. Simulations showed only groundwater from deep within the aquifer would have elevated DDT concentrations in 2003 if DDT leached to groundwater between 1950 and 1970. Conversely, if DDT began to leach to groundwater in the 1990's, the model predicted that DDT was not present in deep groundwater in 2003. With continued loading, concentrations throughout the aquifer will continue to rise into the future and discharge of DDT to the marsh and Lake Erie will occur.

abstract: Thesis

abstract: Master of Science (MSc)


title: WLAN to WWAN Vertical Handovers in Loosely-Coupled Networks

contributor:
Todd, Terence D.
Electrical and Computer Engineering

subject: wireless handsets, LAN, cellular, data, LDU,

abstract:
Wireless handsets are becoming increasingly multi-modal, supporting both cellular
and wireless LAN air interfaces. When such a handset roams from one network to
another during an active voice call, the call must be re-routed into the new network.
The process of re-routing calls in this manner is referred to as a vertical handover.

Achieving seamless WLAN-to-cellular handover can be very difficult due to the
fact that WLAN coverage can often be lost long before a cellular call leg replacement
can be established. A possible worse-case scenario occurs when mobile users walk
from indoor building WLAN coverage to outdoors during voice connections. In this
thesis, results from a measurement-based study of dual-mode handover are given.
The presented results come from extensive IEEE 802.11 measurements that were
made on the McMaster University campus. These results give important insights
into the difficulty of this problem, and relate to various system parameters such as
WiFi deployment type and link loss threshold. The results show that it is almost
impossible to successfully complete the handover unless the WLAN deployment has
been carefully engineered. In WLAN deployments which would ordinarily restrict
the use of lower data rates, the results also suggest that a "limited data rate use"
(LDU) algorithm can greatly improve the probability of seamless handover. This can
be done without adversely affecting the capacity of the WLAN network.

Vertical handover can be performed using enterprise voice gateways which support
basic conference bridging. This feature can be used to achieve soft handover, since
a new leg of the call can be established to the conference bridge while the existing
media stream path is active. Unfortunately this requires that all intra-enterprise calls
be routed through the gateway when the call is established. In this work we consider
a SIP based architecture to perform conferenced dual-mode handover and propose a
much more scalable mechanism for short-delay environments, whereby active calls are
handed off into the conference bridge prior to the initiation of the vertical handover.
Results are presented which are taken from a dual-mode handset testbed, from analytic
models, and from simulations which characterize the scalability of the proposed
mechanism.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Survival and Decline of the Evangelical Identity of the United Church of Canada 1930-1971

contributor:
Gauvreau, Michael
History

subject: United Church of Canada, evangelical, identity, Christian,

abstract: Page 250 was not included becasue it was a blank sheet.

abstract:
Relying on original research and breaking with the dominant interpretations offered so far by historians, this thesis argues that the United Church of Canada maintained an evangelical institutional identity between the 1930s and 1960s despite the fact that its leaders did not hold evangelical beliefs. For a variety of reasons, these leaders found it expedient to promote institutional practices of evangelism, moral reform, and Christian education that embodied evangelical characteristics and therefore projected an evangelical image of the church to its members and the public. At the same time, they personally rejected key evangelical beliefs, a fact that was reflected in the intentional omission of these beliefs from successive official theological statements of the church, although frankly non-evangelical sentiments were rarely found in such statements. This leadership paradigm, which coupled non-evangelical beliefs and evangelical institutional practices, endured into the 1960s.

The tensions inherent between the non-evangelical beliefs held by church leaders and their promotion of evangelical institutional practices made it increasingly difficult for leaders to maintain this paradigm from the 1950s onward. Finally, a series of long-term and short-term catalysts both inside and outside the denomination which converged in the mid-l 960s caused church leaders to abandon the evangelical institutional practices of evangelism, moral reform and Christian education that had defined the church in preceding decades, and simultaneously to state openly their "liberal," non-evangelical beliefs. The result of this major shift, and the ensuing public controversy, was the collapse of the old paradigm and the public redefinition of the United Church as an unambiguously non-evangelical institution. Based on new research into the institutional activities of the United Church after 1930, this conclusion challenges traditional interpretations that have either overlooked the continuing evangelical practices of Canada's largest Protestant denomination or overestimated the extent of its commitment to evangelicalism in this period.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Untimely Deaths in Renaissance Drama: Shakespeare, Middleton, Marlowe

contributor:
Ostovich, Helen
English

subject: plays, Shkespeare, Middleton, Marlowe, historiographical works, untimely death, ,

abstract: In this dissertation, I read several early modern plays - Shakespeare's Richard II, Middleton's A Chaste Maid in Cheapside, and Marlowe's Dido, Queene of Carthage - alongside a variety of early modem historiographical works. I pair drama and historiography in order to negotiate the question of early modem untimely deaths. Rather than determining once and for all what it meant to die an untimely death in early modem England, I argue here that one answer to this question requires an understanding of the imagined relationship between individuals and the broader unfolding of history by which they were imagined to be shaped, which they were imagined to shape, or from which they imagined to be alienated. I assume here that drama - particularly historically-minded drama - is an ideal object to consider when approaching such vexed questions, and I also assume that the problematic of untimely deaths provides a framework in which to ask about the historico-culturally specific relationships that were imagined to obtain between subjects and history. While it is critically commonplace to assert that early modern drama often stages the so-called "modern" subject, I argue here that early modern visions of the subject are often closely linked to visions of that subject's place in the world, particularly in the world that is recorded by historiographers as a world within and of history. I argue that one can begin to make sense of deaths in terms of their timeliness or untimeliness only by recognizing historically specific senses of the narrativized subject and the imagined relationship between that subject and history.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Field and Modeling Study of DDT in Soil and Groundwater Following In-Situ Soil Remediation

contributor:
Smith, James E.
Environmental Science

subject:
DDT, DDE, DDD
Point Pelee National Park
chlorinated pesticides
half-life

abstract:
<p>The shallow soils of a former orchard area in Point Pelee National Park, near
Leamington, Ontario, Canada have elevated concentrations of chlorinated pesticides
above the regulatory limits. Previous studies in this area have shown that the DDT, DOE
and ODD are highly persistent with an estimated half-life of DDT in the range of 15-30
years. In 2002 a pilot-scale field remediation experiment involving the application of
cyclodextrin was conducted. This experiment resulted in substantial decrease of DDT,
DDE and DDD concentrations in the upper soil layer within the remediation grid. Soil
samples were collected within the treatment plots a year after the cyclodextrin application
was completed to assess any further changes in concentrations of DDT, DDE and DDD.
Groundwater samples were collected in the vicinity of the soil remediation grid which
provided DDT, DDE and DDD concentrations in groundwater to assess the vertical
mobilization of the compounds. Mass balance of the "soil - groundwater" system was
calculated in order to estimate the degradation rate of DDT within the remediation zone.
The 2-D unsaturated/saturated flow and solute transport numerical model
"HYDRUS 2-D" was used to gain a better estimation of DDT, DDE and DDD mass and
distribution in groundwater. The effectiveness of cyclodextrin application for remediation
of DDT contaminated soils was assessed. After remediation treatments had stopped, there
was no indication of further degradation of DDT and its metabolites in the upper layer of
soil. The groundwater concentration of DDT, DDE and DDD near the remediation grid
was 10-100 times higher than background value. This increase in groundwater
concentration is a direct indication of DDT, DDE and DDD mobilization by cyclodextrin.
The estimates of total mass of DDT in groundwater are less than 1% of mass leached
from the soil. It was concluded that the application of cyclodextrin promoted enhanced
co-metabolic biodegradation of DDT and it metabolites DDE and DDD. The estimated
half-life for the displaced DDT was less than 2 months. This work demonstrates that
cyclodextrin can be a highly effective agent for remediation of DDT contaminated soils.<p>

abstract: Thesis

abstract: Master of Science (MSc)


title: Design of Linear and Non-Linear MIMO Transceivers: Single and Multiple User Systems with Different Channel Knowledge Assumptions

contributor:
Davidson, Timothy N.
Electrical and Computer Engineering

subject: MIMO, communication systems, linear, nonlinear, single, multiple users, MAC, SINR, signal

abstract:
This thesis considers wireless multi-input multi-output (MIMO) communication systems in block flat-fading environments. It develops novel designs of transmission and reception schemes for single-user and multi-user systems. The designs are developed under different models for the information about the communication channel that is available at the transmitter.

For single-user systems, the thesis studies the class of non-linear MIMO transceivers that implement sequential interference (pre-) subtraction, namely transceivers with Tomlinson-Harashima precoding (THP) and transceivers with decision feedback equalization (DFE). For these transceivers a novel design framework is developed to unify the design of these two dual systems when channel state information (CSI) is available at both the transmitter and the receiver. The framework encompasses a broad range of performance criteria, and generates closed-form expressions for the optimal designs under these criteria. The framework reveals that a single transceiver design is optimal for a large subclass of these performance criteria and shows that this unique optimal design is (strictly) superior to the corresponding optimal linear transceiver for the same performance criterion. The framework also characterizes another class of design criteria for which the optimal non-linear transceiver reduces to the optimal linear transceiver for the same criterion. This novel design framework brings the design of non-linear MIMO transceivers to a level of maturity similar to the linear counterparts, and will impact the design of practical wireless communication systems that implement these interference subtraction schemes. The framework is then generalized to the case of DFE transceivers that satisfy an additional zero-forcing (ZF) constraint and operate in a "limited feedback" regime in which CSI is available only to the receiver and there is a limited rate feedback channel between the receiver and the transmitter. The proposed limited feedback system is the first that involves a "precoded" DFE transceiver.

 The multi-user part of the thesis develops multi-user transceivers that are robust to uncertainties in the available information about the users' channels. These uncertainties are inevitable in most practical multi-user communication systems, and can result in significant performance degradation.

 The first component of the multi-user part develops robust broadcast channel transceivers with quality of service (QoS) requirements for communication scenarios with bounded channel uncertainty at the transmitter. It formulates design problems for QoS requirements that can be expressed as constraints on the signal-to-interference-plus-noise-ratio (SINR) of each user, or as constraints on the mean square error (MSE) each user's received signal. For both formulations, convex and efficiently solvable design approaches are proposed. These design approaches are used to derive solutions to other related design problems, such as robust counterparts of the fair broadcasting problem.

 The second component of the multi-user part develops robust designs for multiuser transceivers that minimize different MSE criteria subject to a power constraint. The designs are obtained for different models of channel uncertainty: stochastic uncertainty models and bounded uncertainty models. For each channel uncertainty model, the robust multi-user designs are developed for both linear and non-linear MIMO transceivers, for both broadcast channels (BC) and multiple access channels (MAC).

Simulation studies demonstrate the impact of the proposed robust designs on the performance of multi-user systems, and show that by incorporating robustness in the design one can significantly reduce the sensitivity of these systems to channel uncertainty and mitigate its deleterious effects.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Density Functional Modeling of Mechanical Properties and Phase Transformations in Manocrystalline Materials

contributor:
Provatas, Nikolas
Materials Science and Engineering

subject:
phase field technique
crystal lattice
free energy
"reverse" Hall-Petch effect

abstract:
We introduce a new phase field technique that incorporates the periodic nature of a crystal lattice by considering a free energy functional that is minimized by periodic density fields. This free energy naturally incorporates elastic and plastic deformations and multiple crystal orientations. The new phase field technique can be used to study a host of important phenomena in material processing that involve elastic and plastic effects in phase transformations. This novel phase field approach is used to study elastic and plastic deformation in nanocrystalline materials with a focus on the "reverse" Hall-Petch effect. In addition we apply the method to dendritic solidification
in binary alloys and the role of dislocations in spinodal decomposition.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Bertrand Russell's Bundle Theory of Particulars

contributor:
Griffin, Nicholas J.
Philosophy

subject:
Bertrand Russell
bundle theory of particulars
ultimate reality
individuation
necessity
analyticity

abstract:
This thesis is an examination of Bertrand Russell's realist "bundle theory of particulars". In Russell's earlier work, the need to explain the unity and individuality of objects compelled him to accept particulars as well as universals as ultimate kinds of reality. Nevertheless, in carrying out his efforts to economize his ontology, he discovered he could not reduce properties to particulars, because there are some relations that resist nominalistic explanation, but particulars could be reduced to bundles of qualities. In this
thesis, I show that the realist 'bundle theory' not only reduces the kinds of ultimate reality to one, i.e., to universal qualities, but also serves all of the purposes for which bare particulars were originally required. Specifically. I examine what I take to be the major criticisms leveled against the realist 'bundle theory': the problem of individuation, the problem of necessity, and the problem of analyticity. I defend the strength and consistency of Russell's theory and argue that it can answer to the objections.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Filiform-Like Corrosion Mechanism on Magnesium-Aluminum and Magnesium-Aluminum-Zinc Alloys

contributor:
Kish, Joseph R.
McDermid, Joseph R.
Materials Science and Engineering

subject:
Magnesium
Corrosion
Filiform
Scanning Vibrating Electrode Technique
Transmission Electron Microscopy
Auger Electron Spectroscopy

abstract: The filiform-like corrosion of Magnesium (Mg) alloys AZ31B and AM30 was investigated with electrochemical and microanalytical techniques. Potentiodynamic polarization testing and scanning vibrating electrode technique (SVET) measurements confirmed the “differential electrocatalytic” mechanism previously reported for filiform and filiform-like corrosion on pure Mg and AZ31B. Transmission electron microscopy (TEM) and Auger electron spectroscopy (AES) revealed that the MgO corrosion filaments on both alloys were likely a product of the direct reaction of Mg and water (H2O), responsible for the rapid hydrogen (H2) evolution observed at the propagating corrosion fronts. TEM analysis also revealed through-thickness cracks and noble intermetallic particles within the corrosion filaments and noble metal enrichment at the corrosion filament/metal interfaces, which were proposed to play significant roles in the cathodic activation of the corrosion filaments. The higher susceptibility of the AZ31B alloy to cathodic activation versus AM30 suggested that Zinc (Zn) has a detrimental effect on the resistance of Magnesium-Aluminum-Zinc (Mg-Al-Zn) alloys to filiform and filiform-like corrosion.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Breast Cancer, Femininity, Embodiment, and the Sport of Dragon Boat Racing

contributor:
Pawluch, D.
Sociology

subject: women, boat racing, dragon, breast cancer, sport, bodies

abstract:
 In this dissertation the author provides an analysis of three separate but interrelated aspects of the experiences of women who have been treated for breast cancer and who participate in survivor dragon boat racing.

 In the first analysis the author addresses the multiple meanings and functions that this physically intense competitive team sport has for the women. The paper explores some of the reasons why this activity appealed to them and the kinds of impacts and effects that participation in this activity had on their lives. The second analysis offers a critical look at the ways in which breast amputation has been characterised within the medical and breast cancer literature as a threat to women's self identity as female or feminine. The data from this study however demonstrates that women's experiences of
breast amputation is much more complex and nuanced than characterised. Also included is an examination of women's own perspectives on this experience, as well as the mediating role that dragon boat racing had on this aspect of self identity. The third analysis focusses on a major theme that emerged from the data which was the transformative effect that competitive dragon boat racing had on women's bodies and on their sense of self. Discussed here are the impacts and effects that participation in
competitive dragon boat racing had on women's self identities and bodies and that enabled the women to see themselves as strong, fitter, healthier and "better" than what they were prior to their breast cancer illness experience. Finally, the author concludes with a discussion of how regular participation sport, and especially for women living with a critical illness, can empower women at the individual, group and societal levels.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Reliability Analysis and Robust Design of Metal Forming Process

contributor:
Nye, Tim J.
Wu, Peidong
Mechanical Engineering

subject: metal forming process, robust, product, reliable, design, (FLD),

abstract:
Metal forming processes have been widely applied in many industries. With the severe competition in the market, a reliable and robust metal forming process becomes crucial for the manufacturer to reduce product development time and cost. For the purpose of supplying engineers with an effective tool for a reliable and robust design of metal forming process, this research investigates the application of traditional reliability
theory and robust design methods in metal forming processes for the ultimate goal of increasing quality and reducing cost in manufacturing.

 A method to assess the probability of failure of the process based on traditional
reliability theory and the forming limit diagram (FLD) is presented. The forming limit of a material is chosen as the failure criteria for analysis of reliability.

 A study of prediction of forming limit diagrams using finite element simulation without pre-defined geometrical imperfection or material imperfection is presented. A 3D model of the dome test is used to predict the FLD for AA 5182-0. The FE predicted forming limit diagram is in good agreement with the experimental one. The uncertainty sources for the scatter of forming limits are categorized and investigated to see their
effects on the shape of FLD.

A novel method of improving the reliability of a forming process using the Taguchi method at the design stage is presented. The thickness-thinning ratio is chosen as the failure criteria for the reliability analysis of the process. A Taguchi orthogonal array is constructed to evaluate the effects of design parameters on the thinning ratio. A series of finite element simulations is conducted according to the established orthogonal array. Based on the simulation results, Taguchi S/N analysis and ANOVA analysis are applied to identify the optimal combination of design parameters for minimum thinning ratio, minimum variance of thinning ratio, and maximum expected process reliability.

 A multi-objective optimization approach is presented, which simultaneously
maximizes the bulge ratio and minimizes the thinning ratio for a tube hydroforming process. Taguchi method and finite element simulations are used to eliminate the parameters insignificant to the process quality performance. The significant parameters are then optimized to achieve the multiple optimization objectives. The optimization problem is solved by using a goal attainment method. An illustrative case study shows the practicability of this approach and ease of use by product designers and process engineers.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Structuring Gold Nanoparticles Using DNA: Towards Smart Nanoassemblies and Facile Biosensors

contributor:
Brook, Michael A.
Li, Yingfu
Chemistry

subject: gold, nanoparticles, DNA, nanoassemblies, facile biosensors

abstract:
This thesis has exploited the use of gold nanoparticles (AuNPs)/DNA conjugates towards 1) the development of simple colorimetric assays to monitor DNA functions and relevant biological processes, and 2) the control the nanoassembly of AuNPs using biomolecules and biological processes.

DNA has a number of attractive functions including specific biorecognition,
catalysis and being manipulated by protein enzymes, etc. These characteristics were exploited to permit nanoassembly to be responsive to a specific stimulus and also ensure the specificity and precision in the construction of well-defined 3D nanostructures. Meanwhile, the assembly or disassembly of AuNPs, which results in distinct color changes due to the localized surface plasmon resonance, provides an excellent platform
for the colorimetrically monitoring the DNA functions and the relevant biological processes.

We have specifically investigated how the surface charges, the length and
conformations of surface-tethered DNA polymers affect the assembly of AuNPs. We found that the colloidal stability of AuNPs can be well-tuned by nucleotides (small charged molecules) with various binding affinity to AuNP surface and/or different number of negatively-charged phosphate groups. This relies on the fact that nucleotides can bind to AuNP surface via nucleobase-Au interaction, and negatively charged
phosphates stabilize AuNPs via electrostatic repulsion. This investigation allowed us to monitor protein enzymatic reactions where nucleotides are modified by alkaline phosphatase and to control the growth of AuNPs using nucleotides as capping ligands.

We then investigated the effect of the length of DNA polymers on AuNP surface on AuNP colloidal stability. DNA-modified AuNPs are stabilized electrosterically at a relatively high salt concentration; the removal (or shortening) of the DNA molecules by enzymatic cleavage or the dissociation of DNA aptamers from AuNP surface upon  binding to their target destabilizes AuNPs and results in AuNP aggregation. We attribute this to the loss of negatively-charged polymeric DNA molecules that initially served as
colloidal stabilizers. This has been applied to the monitoring of enzyme (both protein enzyme and DNA enzyme) cleavage of DNA molecules, and DNA aptamer binding event to its target, respectively.

 We also studied how DNA polymer conformational changes influence AuNP colloidal stability, which has been employed to monitor DNA aptamer folding events on
the AuNP surfaces. We found that AuNPs to which folded aptamer/target complexes are attached are more stable towards salt induced aggregation than those tethered to unfolded aptamers. Experimental results suggested that the folded aptamers were more extended on the surface than the unfolded (but largely collapsed) aptamers in salt solution. The
folded aptamers therefore provide higher stabilization effect on AuNPs from both the electrostatic and steric stabilization points of view.

 Finally, we demonstrated the well-defined assembly of AuNPs using long
(hundred nanometers to microns) single-stranded (ss) DNA molecules as template in a three-dimensional (3D) fashion. Specifically, these long ssDNA containing repeating units are generated by protein enzymatic reaction (DNA extension through rolling circle amplification) on AuNP surface. The resultant product provides a 3D-like scaffold that can be subsequently used for periodical assembly of complementary DNA-attached nanospecies.

 We also expect that the facile colorimetric biosensing assays developed in this thesis work provide an attractive means to study biomolecular behaviors (e.g, biorecognition and conformational changes) on the surface, and to investigate other common DNA (or RNA) structural (e.g., triplex, G-quadruplex, hairpin, i-motif) and protein structural transitions.

 Finally, this thesis work provides some novel and general strategies for the control of nanoassemblies by tuning surface charges and surface-tethered polymers. We expect these principles can also be applied in other AuNP-based sensing platforms that exploit interparticle interactions and in the construction of well-defined nanostructures which involves other types of nano-scaled materials (e.g., quantum dots, nanotubes, nanowires, etc).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: New Nonparametric Tests for Panel Count Data

contributor:
Balakrishnan, Narayanaswamy
Mathematics

subject: panel, count data, nonparametric, (NPMLE), tests

abstract:
 Statistical analysis of panel count data is an important topic to a number of applied fields including biology, engineering, econometrics, medicine, and public health. Panel count data include observations on subjects over multiple time points where the response variable is a count or recurrent event process when only the numbers of events occurring between observation time points are available. The choice of method for analyzing panel count data usually depends on the relationship between the observation times and the response variable and questions of interest. Most of the previous research was done when the observation times are fixed. If the observation times are random, the data structure becomes more challenging since the observation times for individual subjects vary in addition to the incompleteness of observations. The model-based approach was used to deal with such data. However, this method relies on extra assumptions on the observation scheme and thus is restrictive in practice. In this dissertation, we discuss the problem of multi-sample nonparametric comparison of counting processes with panel count data, which arise naturally when recurrent events are considered. For the problem considered, we develop some new nonparametric tests.

 First, we construct a class of nonparametric test statistics based on the integrated weighted differences between the estimated mean functions of the count processes, where the isotonic regression estimate is used for the mean functions. The asymptotic distributions of the proposed statistics are derived and their finite-sample properties are examined through Monte Carlo simulations. A panel count data from a cancer study is analyzed and presented as an illustrative example.

As shown through Monte Carlo simulations, the nonparametric maximum likelihood estimator (NPMLE) of the mean function is more efficient than the nonparametric maximum pseudo-likelihood estimator (NPMPLE). However, no nonparametric tests have been discussed in the literature for panel count data based on the NPMLE since the NPMLE is more complicated both theoretically and computationally. It is, therefore, particularly important to develop nonparametric tests based on the NPMLE for panel count data.

 In the second part of the dissertation, we focus on the situation when treatment indicators can be regarded as independent and identically distributed random variables and propose a nonparametric test in this case using the maximum likelihood estimator. The asymptotic property of the test statistic is derived. Simulation studies are carried out which suggest that the proposed method works well for practical situations, and is more powerful than the existing tests based on the NPMPLEs of the mean functions.

In the third part of the dissertation, we consider more general situations. We construct a class of nonparametric tests based on the accumulated weighted differences between the rates of increase of the estimated mean functions of the counting processes over observation times, where the nonparametric maximum likelihood approach is used to estimate the mean functions instead of the nonparametric maximum pseudolikelihood. The asymptotic distributions of the proposed statistics are derived and their finite-sample properties are evaluated by means of Monte Carlo simulations. The simulation results show that the proposed methods work quite well and the tests based on NPMLE are more powerful than those based on NPMPLE. Two real data sets are analyzed and presented as illustrative examples.

The last part of the dissertation discusses a special type of panel count data, namely, current status or case 1 interval-censored data. Such data often occur in tumorigenicity experiments. For nonparametric two-sample comparison based on censored or interval-censored data, most of the existing methods have focused on testing the hypothesis that specifies the two population distributions to be identical under the assumption that observation or censoring times have the same distribution. We consider the nonparametric Behrens-Fisher hypothesis (NBFH) under this settings. For this purpose, we study the asymptotic property of the nonparametric maximum likelihood estimator of the probability that an observation from the first distribution exceeds an observation from the second distribution. A nonparametric test for the NBFH is proposed and the asymptotic normality of the proposed test is established. The method is evaluated using simulation studies and illustrated by a set of real data from a tumorigenicity experiment.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: ASPECTS OF THE MCMASTER INTENSE POSITRON BEAM FACILITY (MIPBF)

contributor:
Mascher, Peter
Engineering Physics

abstract: The McMaster Intense Positron Beam Facility (MIPBF) is a project based on the McMaster Nuclear Reactor (MNR) that aims to set up the first intense positron beam in Canada. The final intensity of the moderated positron flux is expected to be 109/s, which will make the positron beam one of the most intense ones in the world. A general review of intense beams, including the linac-based positron beams and reactor-based positron beams, applied around the world will be given. The details of the MIPBF project, especially the defect characterization system will be discussed in the thesis. A beam system for out of core test of the defect characterization system has been constructed. Components in spectrum acquisition and analysis system have been calibrated and tested. A simple coincidence Doppler broadening spectroscopy system has been set up. An electron beam for simulating the positron beam has been tested successfully. The experiments on beam transportation will be discussed. A new positron source and a moderator have been installed in the beam system. The operational procedures and instructions of the beam system will be provided.

abstract: Thesis

abstract: Master of Applied Science (MASc)