VictorJuiz/thesis huggingface dataset:
Microresonators for nonlinear quantum optics

In this thesis I study in detail the quantum dynamics of several nonlinear optical processes in microresonator systems. A Heisenberg-picture input-output formalism is developed from first principles that includes the effects of scattering losses and independent quality factors and coupling ratios for different resonances. The task of calculating the device output is then reduced to solving a set of driven, damped, ordinary differential equations for the resonator mode operators alone. This theoretical framework is used to study photon pair generation via spontaneous four-wave mixing in the weakly pumped regime, on which the effects of scattering losses are appraised. A more strongly driven regime is studied for continuous wave pumps, demonstrating when self- and cross-phase modulation and multi-photon pair generation become important, and their effects on the spectral and power scaling properties of the system are examined; A detuning strategy is presented that compensates for some of these effects. The results of the weak-pump regime are applied to study microresonator-based her- alded single photon sources. The impact of scattering losses is studied, revealing that typical systems suffer from low heralding efficiency due to these losses. A technique to improve heralding efficiency is presented through over-coupling the resonator-channel system, and a resultant trade-off between heralding rate and heralding efficiency is un- covered. Limitations to the spectral purity of the heralded single photon output for conventional microresonator systems are also analysed, and a more sophisticated cou- pling scheme presented to overcome the upper bound for spectral purity of 93% that exists in typical systems, permitting the generation of single photons with spectral pu- rity arbitrarily close to 100% without spectral filtering or sophisticated phase-matching techniques. The theory of quantum frequency conversion in microresonators using four-wave mix- ing is then developed in detail, and the spectral conversion probability and conversion efficiency studied. Efficiencies exceeding 90% using less than 100 mW of pump power are predicted to be achievable with current technology. A dressed mode picture is developed to better understand the conversion dynamics. Rabi-like spectral splitting and temporal oscillations of the intraresonator mean photon number are predicted, exhibiting a novel regime of strongly coupled photonic modes.

Advisor: Sipe, John E
Visions of Unity: Philosophical Realism in Late Fourteenth-Century English Dream-Vision Poetry

Over the past half-century literary critics have frequently depicted late fourteenth-century Middle English poetry, including dream-vision poetry, as endorsing nominalism. Scholars defending this claim have often started from a construal of nominalism now considered obsolete, yet it remains commonplace to find authors including Chaucer and Langland described as affirming nominalist views. This is unfortunate, for it is now known that late fourteenth-century English philosophers normally rejected nominalism. To the contrary, especially extreme forms of realism, the position opposed to nominalism, became preponderant. This thesis aims to restore late fourteenth-century English dream-vision poetry to its correct intellectual context. More fully, it contends that taking realism to underwrite the dream visions Pearl, Langland’s Piers Plowman, and Chaucer’s House of Fame unlocks insights foreclosed by the assumption that these poems presuppose nominalism. This thesis first clarifies the character of realism and nominalism in fourteenth-century England. Realism and nominalism have been mistaken for theological outlooks, and nominalism has been equated with skepticism. But medieval nominalists did not advocate skepticism, and realism and nominalism are fundamentally philosophical stances. I show that realism and nominalism centre on incompatible views about how language is related to reality and that, secondarily but not less importantly, realism and nominalism entail incompatible views about whether or not individuals are metaphysically interconnected by common properties. Another position, idealism, also enters the debate insofar as realists held that nominalism leads to idealism. I then turn directly to Pearl, Piers Plowman, and The House of Fame. My readings of Pearl and Piers Plowman propose that they present, respectively, heavenly delight and human nature in a realist light—i.e., as common properties. My reading of The House of Fame offers that this text casts nominalism as leading to idealism. All three interpretations further understand these works’ authors, like contemporaneous realist philosophers, as deeming realism essential for ascent to the divine. Realism emerges as an important underpinning of poems which, by virtue of this realist basis, I consider visions of unity.

Keywords: dream-vision
House of Fame
nominalism
Pearl
Piers Plowman
realism
Advisor: Akbari, Suzanne C
Working in ‘Bad Jobs’: Immigrants in the New Canadian Economy

Beginning in the late 1960s, the Canadian economy experienced two significant changes: the growth of immigrants from non-traditional source regions and major economic restructuring. The work transformation significantly undermined the quality of work, leading to a growing number of ‘bad jobs’, characterized by low wages, lack of fringe benefits, and declining union coverage. The literature on work transformation, however, relies primarily on macro-level theorizing, and pays less attention to how new forms of inequality emerge from these changes. Alternatively, studies on immigrants’ economic integration tend to rely on single-dimension, orthodox indicators of economic outcomes, such as earnings, and many do not incorporate the context of the new economy. Among the studies that do, the use of small samples and qualitative measures limit the ability to identify patterns of inequality. My dissertation fills this gap in the literature by bringing together these two intricately intertwined, yet disparate sets of literature. I analyze how job quality differs significantly by nativity status and demonstrate immigrants’ overrepresentation in ‘bad jobs’. I study immigrants’ disadvantage on three levels, in three independent papers: 1) likelihood of engaging in ‘bad jobs’, 2) differential long-term outcomes of engaging in ‘bad jobs’, and 3) household-level inequalities based on job quality and nativity status of the household head. I analyze the Survey of Labour and Income Dynamics, using both cross-sectional and panel data, as well as household-data, which I constructed from cross-sectional individual files. I find that immigrants experience significant disadvantage in the new Canadian economy: they are more likely to work in ‘bad jobs’ and stay in ‘bad jobs’ than the Canadian-born. These individual-level inequalities also translate to household-level inequalities in terms of likelihood of living low-income. The results from this dissertation draw attention to stratification within the new economy and incorporates the context of the new economy into the study of immigrant integration.

Keywords: immigration
inequality
job quality
labour market
new economy
work
Advisor: Boyd, Monica
Dynamic Trading in a Limit Order Book: Co-Integration, Option Hedging and Queueing Dynamics

We show how an agent dynamically trades in a limit order book, accounting for asset co-movement, exposure to a contingent claim and queue position of limit orders. Inspired by real-world trading problems, we propose models that capture relevant market dynamics and formulate stochastic control problems for the agent. We derive the associated dynamic programming equations and prove existence and uniqueness of the solutions under mild conditions. We provide numerical schemes to solve the equations and address convergence issues, when appropriate. We calibrate the models to real data and demonstrate the optimal strategies by numerical examples. Our work is complete in that it bridges the gap between abstract mathematical theory and practical implementation. For an agent executing a basket of assets, we show how she can improve her strategy by employing information from co-movements of multiples assets, even if some assets are outside of the basket. We derive the agent's trading speed in closed-form and use simulations to demonstrate the performance of the optimal strategy. Furthermore, for an agent who takes a short position in a contingent claim, we show how she maximizes her expected utility of wealth by trading the underlying asset. She employs market orders to keep the inventory on target to replicate the payoff of the claim and uses limit orders to build the inventory at a favorable price and boost expected terminal wealth by completing round-trip trades that earn the spread. Finally, we show how an agent incorporates queue position of her limit order in the decision of whether to cancel the order or let it rest. The extra information on queue position enables the agent to better predict the execution time of the order and the time that the limit order book switches regime. A simulation study demonstrates that the optimal strategy significantly outperforms a benchmark that ignores the effect of queue position.

Keywords: algorithmic trading
co-integration
limit order book
optimal execution
option hedging
queueing system
Advisor: Jaimungal, Sebastian
The Legal Duty to Accommodate Faith and Religion in Ontario's Public Schools: An Exploratory Case Study

Abstract Ontario public schools have become a focal point—and contested sites—where the dichotomy of a proclaimed secular stance must be reconciled with the legal duty to accommodate diverse faiths and religions. This exploratory case study examines the experiences of principals in addressing the challenge of ensuring the public school is positioned as secular, while simultaneously accommodating the faiths and religions of Ontario’s increasingly diverse, multi-cultural society. When competing rights under the Canadian Charter or Human Rights Code come into conflict it can present a complex challenge. To provide context for this exploratory case study jurisprudence, legislation and school policy, developed post-Charter, are reviewed. With this legal framework data from interviews with twelve elementary and secondary principals from five Ontario public boards are examined to learn how the principals enact, integrate, and mobilize the duty to accommodate faith and religion in their ‘secular’ schools. What is the impact on how schools function? How is conflict managed when religious tenets conflict with other equal but competing rights, such as sex equity, same sex relationships, or freedom of speech? Is there a tipping point—a point of ‘undue hardship’—where a principal must declare a religion-based request as deleterious to the rights of others, and thus impossible to accommodate? The study demonstrates the legal duty to accommodate faith and religion in Ontario’s bourgeoning multi-faith society adds to the complexity of the principal’s role in ensuring the religious diversity of students and staff is recognized, included and integrated into the fabric of our public schools. The study also demonstrates the successful accommodation of faith and religion is facilitated through the principal’s mindset of inclusivity, respect for difference, engagement with the community—including religious leaders—and knowledge of the law. The growing influence of Muslims and Islam in our schools and their accommodation needs are also recognized. Principals particularly acknowledge the new health education curriculum which has created discord with Christians and non-Christians. Opposition to content on same-sex relationships places principals in an untenable position between accommodating religious beliefs and safeguarding the rights of the LGBTQ communities. Principals are greatly challenged by the dilemma.

Keywords: equity
inclusivity
legal duty
multiculturalism
principals
religion
Advisor: Portelli, John
Weld Effective Lengths for Hollow Structural Section Connections

An experimental and finite element (FE) research program was conducted to investigate the â fit-for-purposeâ design of welds in hollow structural section (HSS) connections using weld effective lengths, and the applicability of the North American directional strength-increase factor for fillet welds to HSS. Weld effective lengths for circular hollow section (CHS) connections are studied for the first time. Experimental testing of a 10-m span, simply-supported, rectangular hollow section (RHS) Warren truss, with fillet- and groove-welded overlapped K-connections, was performed by applying a single quasi-static point load to truss panel points to cause sequential rupture of nine test welds to overlapping branches. The weld in-situ strength, effect of key connection parameters, and safety (reliability) index of AISC formulae for weld design in RHS overlapped K-connections were determined. Modifications to the AISC formulae and a simplified method for modelling overlap-jointed RHS trusses under service load conditions are proposed. The North American directional strength-increase factor for fillet welds to HSS (covering both RHS and CHS) was then studied through 33 experimental tests and 73 non-linear FE analyses of weld-critical HSS-to-rigid plate connections. The safety index was determined for prominent North American design codes, and a recommendation to prohibit the use of the directional strength-increase factor for the design of fillet welds to all HSS was made. More accurate design formulae for fillet welds to HSS are proposed. Twelve large-scale experiments and 256 non-linear FE tests were then conducted to determine weld effective lengths for CHS-to-CHS X- (or Cross-) connections, which are shown to decrease as branch-to-chord width ratio, chord wall slenderness, and branch-to-chord thickness ratio increase. North American fillet weld design formulae were found to already provide adequate reliability provided that the directional strength-increase factor is not used. A new fillet weld design approach for CHS X-connections, using weld effective lengths, is proposed.

Keywords: Connection
Effective Length
Finite Element
Hollow Section
Steel
Weld
Advisor: Packer, Jeffrey A
Motion Compensated Magnetic Resonance Imaging of the Fetal Heart

Cardiac Magnetic Resonance (CMR) imaging has the potential to be a useful prenatal diagnosis tool in cases of congenital heart disease (CHD), but is challenging due to the size of fetal cardiac structures, relatively high fetal heart rates, and multiple sources of motion. In this thesis, novel methods are developed to acquire fetal CMR data with clinically useful spatial and temporal resolution while compensating for the effects of maternal respiration, fetal cardiac motion, and gross fetal movement. Chapter 1 describes the motivation for this work: the diagnosis of congenital heart disease in utero. A brief overview of CHD is provided including current diagnosis strategies with the primary fetal imaging modality, ultrasound. Chapter 1 also addresses the theory behind conventional acquisition and reconstruction techniques for CMR. Chapters 2 and 3 discuss the theory, implementation, and validation of novel approaches to accelerated imaging and motion compensation for fetal CMR. Chapter 4 presents preliminary clinical applications of these methods along with a comparison to fetal echocardiography. Finally, Chapter 5 discusses future work including improvements to the current methods and extensions to other aspects of fetal cardiac imaging.

Keywords: Accelerated Imaging
Compressed Sensing
Fetal Heart
Magnetic Resonance Imaging
Motion Correction
Advisor: Macgowan, Christopher K
Retrieving Canopy-Level Light Use Efficiency (LUE) and Maximum Carboxylation Velocity (Vcmax) Using the Photochemical Reflectance Ratio

In many terrestrial biosphere models, the photosynthesis is simulated following Farquhar’s scheme, in which the maximum carboxylation velocity (V_cmax) is a crucial parameter. Recent observations suggest that the traditional way of parameterizing V_cmax as values associated with plant function types (PFTs) is insufficient in portraying its spatial variations. To improve the spatial resolution of V_cmax, an indirect method for regional V_cmax estimation using remote sensing technique is developed and tested in this dissertation. The method involves two major steps: 1) V_cmax inversion using the gross primary productivity from light saturated sunlit leaves (〖GPP〗_sun), and 2) calculation of 〖GPP〗_sun through the sunlit light use efficiency (ε_sun) obtained based on its correlation with the remotely sensed photochemical reflectance ratio (PRR). These two steps are first tested separately at site level and then combined to estimate regional V_cmax using the MODIS-driven PRR. Site level 〖GPP〗_sun is separated from the flux-derived GPP using a light response curve approach for six Canadian flux sites and then used to invert V_cmax for the sites. The inverted V_cmax matches well with V_cmax obtained for same sites by previous studies, supporting the reliability of the inversion method. The uncertainty of the V_cmax is estimated to be within 25% of the mean value. The estimation of ε_sun requires the establishment of a general PRR —ε_sun relationship across different PFTs. To study the PRR —ε_sun relationship, multi-angular canopy reflectance measurements were taken for an evergreen coniferous site and a deciduous broadleaf site. The PRR from sunlit leaves (〖PRR〗_sun) is extracted from the observed PRR with the aid of a bidirectional reflectance distribution model called four-scale model. Significant correlations between 〖PRR〗_sun and ε_sun are found in both sites but with different regression parameters. A generic relationship is achieved for the two sites by correcting 〖PRR〗_sun with NDVI (〖NPRR〗_sun= 〖PRR〗_sun* NDVI, r2 = 0.48, p

Keywords: BRDF
LUE
MODIS
PRR
Vcmax
Advisor: Chen, Jing
Parallel Ultra-Short Reach Die-to-Die Links

The demand for higher aggregate bandwidth at all levels of communication infrastructure has been driving research into chip-to-chip communication over short printed circuit board (PCB) traces to its limit, and given rise to chip-to-chip links over short traces on a common packaging substrate or so-called interposer. The latter, referred to as die-to-die communication, is the focus of this thesis. In particular, different interconnect technologies and circuit techniques are explored to maximize the aggregate data rate between chips. A link model is presented to compare different substrates and die-substrate attachment methods. The model performance is veried against measured results of a 4-4-4 organic substrate and silicon interposer fabricated in a 0.35 um CMOS technology. Using the link model, an appropriate signaling scheme, termination impedance, and interconnect spacing is demonstrated for each technology. Moreover, the maximum achievable data rate is determined over different die-to-die interconnects. In addition, a prototype single-ended parallel interface is presented. The interface includes a low-power transceiver and a high-density low-cost silicon interposer. The link architecture exploits single-sided and capacitive termination, passive equalization in the transmitter, and CMOS logic-style circuits. The transceiver prototype integrates 3 transmitters and 3 receivers fabricated in 28 nm FD-SOI CMOS technology. The parallel interface operates at 20 Gb/s/wire while consuming 0.30 pJ/bit excluding clocking circuits. Finally, an overview of the clocking architecture for parallel die-to-die links is presented. A phase rotator is designed and fabricated in 28 nm STM FD-SOI CMOS technology as part of a half-rate wireline receiver which operates at 16 Gb/s. The phase rotator comprises of an Injection Locked Oscillator (ILO) and two pseudo-differential CMOS Phase Interpolators (PIs).

Keywords: Chip to Chip Communication
Die to Die Links
Low Power Transceivers
Silicon Interposers
Ultra Short Reach Links
Wireline Communication
Advisor: Chan Carusone, Anthony
Racially "Indian", Legally "White": The Canadian State's Struggles to Categorize the Métis, 1850-1900

The Canadian state has constantly been faced with a paradox: differentiated rights and regulations required it to define the boundaries of the invented category "Indian," yet it was never able to do so satisfactorily. The existence of mixed-ancestry and Métis people disrupted its seemingly clear categories of "Indian" and "White." This thesis asks three central research questions: how did the Canadian state understand the category they called "half breeds;" what cultural and intellectual ideas informed these notions; and what was their impact? There was no single meaning or understanding of the term "Half Breed," but it was in fact characterized by inconsistency, ambiguity, contradiction, and confusion. There were two significant opposing forces at play: 1) the need to consolidate the power of the emerging state, which usually meant grouping the Métis and people of mixed ancestry in with “Indians” in order to better control them, and 2) the desire to save money, which usually meant separating out “half breeds” as a way of reducing the number of status Indians (to minimize the scope of the state’s fiscal responsibilities). The Métis presented themselves as a free “civilized” Indigenous People, but for the government, the term "half breed" was most useful as a floating signifier, with no stable meaning. In an era of increasing state rationalization, the sliding signifier allowed for flexibility in otherwise rigid laws and policy, aiding the state in navigating between its often-conflicting goals. Only in a few instances did the state recognize the Métis as a distinct People. Because of discrimination and the lack of official recognition, many Métis people were dispossessed and hid their heritage. On the other hand, this very ambiguity could provide a degree of freedom, and Métis today are working to define themselves as a distinct people and to fight for their inherent Indigenous rights.

Keywords: British Empire
Canadian Indian Policy
Indigenous Studies
Legal history of Canada
Métis History
State Policy
Advisor: Bohaker, Heidi