VictorJuiz/thesis huggingface dataset:
Mate Searching and Choosiness are Shaped by Spatial Structure and Social Information in Western Black Widows

The relative importance of different episodes of sexual selection for fitness varies with environmental and social context, so inferring the net effect of selection requires understanding how each mechanism operates in nature. Theory predicts that links between ecology, information availability, and mechanisms of sexual selection can have substantive effects on plasticity and behaviour, but these links are rarely demonstrated in the field. Using the western black widow, Latrodectus hesperus, I investigated how ecological factors including demography, OSR, and spatial structure influence male and female reproductive behaviour in the field, and how these are linked by chemical information. I found that the OSR is extremely male biased for most of the mating season, and this imposes strong selection on males to find females before rivals. Mate searching males use social information, likely encoded by chemicals on silk draglines produced by rivals, to efficiently locate females even in the absence of female sex pheromone. In the face of intense scramble competition over access to receptive adult females, I found that males commonly guard and mate with subadult females using a recently-described alternative reproductive tactic: immature mating. Success at this tactic requires contests with rivals, which likely favours different traits than does pure scramble competition over adults, and may help to maintain extreme variation in male size. Moreover, because subadults apparently do not produce volatile chemical cues that would allow males to locate them, the clumped spatial distribution of females in the field is a critical factor influencing the feasibility of immature mating; males only found subadults when there were signaling adults nearby. I also found that for females, proximity to conspecifics during development and early adulthood influences encounter rates with potential mates, such that some females risk remaining unmated in nature. Consequently, females adjust mate-choice decisions in response to chemical information about their local social environment; females in relatively isolated locations display decreased choosiness relative to females in close proximity to conspecifics. Together these studies provide insights into how mate competition and mate choice, key factors driving sexual selection, are related to the spatiotemporal distribution of conspecifics in a natural population.

Keywords: Arachnology
Behavioural ecology
Chemical ecology
Mate searching
Sexual selection
Spider
Advisor: Andrade, Maydianne CB
Exploring the Influence of a Solution-focused Coaching Intervention on Coach Communication Skills and Athlete Self-actualization: An Action Research Study

Abstract This action-research project, which involved a year long, humanistic communication intervention with a female interuniversity sport team, aimed to disrupt the dominant sport discourses that contribute to harmful coach behaviour, athlete compliance and docility. The research questions included: (i) Do solution-focused coaching skills improve the communication skills/behaviours of the coaches?; Are dominant coaching discourses interrupted? If so, how do these changes occur?; (ii) Does solution-focused communication influence the self-actualizing processes of these athletes?; (iii) Does the intervention appear to change team culture, and if so, in what ways? Using a case study design, a critical approach to thematic discourse analysis (Batel Castro, 2018; Braun Clark, 2006) and an interpretive comparative analysis (Fram, 2013, Thorne, 2000) was used to evaluate the effects of a solution-focused coaching intervention on coach learning and development, which was the purpose of this study. The effects were evaluated by their impact on team culture and the self-actualization processes of the athletes. Measures included coach learning sessions, weekly cycles of reflection, planning and action, audio recordings, observations, athlete interviews, written communication and artifacts. Through the perceptions of both coaches and athletes, the team culture transformed from disengaged to engaged, powerful team hierarchies were broken down and conversations became more inclusive, courageous and adult. The athletes’ ability to self-reflect, their agency, and personal insights were amplified. The performance of the team was enhanced. The findings of this collaborative study emphasize the utility of a humanistic, strengths-based approach to coach communication as a means of positively influencing athlete development and team culture. As such, it provides valuable information and insight that may contribute positively to our understanding of how to effectively influence coach learning and development, what constitutes coach learning and development, and the implications of emphasizing communication as a fundamental coaching skill.

Keywords: action research
coaching
cultural psychology
self-actualization
sport coaching
Advisor: Kerr, Gretchen
Fractional Programming for Communication System Design

Fractional programming (FP) refers to the class of optimization involving ratio terms. The traditional techniques for FP, i.e., the Charnes-Cooper method and Dinkelbach’s method, however can only be applied to the single-ratio problem (or the max-min-ratio problem). This thesis aims to develop new techniques for FP to address a broader range of optimization problems consisting of multiple ratio terms, and to investigate their applications in communication system design. Toward this end, we propose a new technique named the quadratic transform to tackle multiple ratios—which can even be nested in some nonlinear functions. We also propose a Lagrangian dual transform in order to tackle the logarithmic ratio problems that are frequently encountered in communication system design. As a further theoretical contribution, the classic scalar FP is generalized to a multidimensional space wherein the ratios are of a matrix form. Remarkably, both of the quadratic transform and the Lagrangian dual transform can be extended to higher dimensions. Moreover, we justify the proposed FP methods by connecting them to the minorization-maximization (MM) theory. On the application side of FP in communication system design, this thesis begins with the continuous optimization of transmit powers and beamforming vectors in the signal-to-interference-plus-noise ratio (SINR) terms. An interesting result about power control is that FP leads to a fixed-point iteration with provable convergence whereas the existing algorithms of the same type cannot guarantee convergence in general. For the discrete optimization, we advocate a novel way of using FP, thereby reformulating the complicated integer programming problem as a weighted bipartite matching problem. A critical aspect of this approach is that it encompasses the weighted minimum mean square error (WMMSE) algorithm as a special case. Finally, we demonstrate the role of matrix FP in optimizing the multi-data-stream transmission for device-to-device (D2D) systems as well as in designing the nonorthogonal pilot sequences for massive multiple-input multiple-out (MIMO).

Advisor: Yu, Wei
New Tools for Evaluating Parallel and Heterogeneous Architectures

Computer architecture is entering its second golden age. The number of servers worldwide is estimated to be ten million. The number of mobile devices in the world now exceeds two billion. But with the decline of technology scaling, performance improvements from shrinking transistors has dwindled. The world now turns to innovations in computer architecture for increased performance. A fundamental aspect of computer architecture is evaluating tradeoffs between design points. Evaluating these trade-offs is becoming more difficult due to the increased complexity of the hardware and applications. Traditional methods for evaluation are useful but limiting. In this dissertation, we propose to remove these limitations by complementing traditional tools with two new ones: Rhythm and Mocktails. The traditional method of simulating parallel systems is limiting for two main reasons. First, only a small sample of a workload’s execution is considered. Second, the input to the application has been reduced in size by orders of magnitude. Rhythm removes these limitations by modeling only the key interactions between the application, system software, and hardware, producing performance estimates in seconds or minutes for full runs of a benchmark with realistic inputs. We validate the fidelity of Rhythm’s estimates to measurements of workloads running on two real systems. Rhythm helps architects gain valuable insights on the performance of parallel architectures in the early stages of design, guiding them toward the design points that should be evaluated in more detail. The rapid evolution of mobile computing has led to a significant degree of heterogeneity in the hardware. The heterogeneity stems from domain-specific accelerators, which limits academic research because these accelerators (and their workloads) are proprietary. Mocktails removes this limitation for architects exploring the memory hierarchy by statistically modeling the memory access behaviour of compute devices without making assumptions about the hardware or workload. We validate the fidelity of Mocktails experimentally for caches and main memory. Architects can use Mocktails in their simulations to mimic the behaviour of a compute device, making the tool a useful conduit between industry and academia.

Keywords: Computer Architecture
Memory System
Performance Analysis
Performance Modelling
Advisor: Enright Jerger, Natalie
Criminal Justice, Indigenous People, and Political Power in Canada

My dissertation contributes to the work of reconciling radically different justice concepts with a view to designing institutions that can be accepted as legitimate by Indigenous and non- Indigenous Canadians alike. The project is principally a work of political theory within Canadian politics, but it draws upon and contributes to literatures in political philosophy, empirical political science, criminology, and law. The central question of my dissertation is, how can criminal justice in Canada be rendered legitimate for Indigenous people? I argue that legitimate criminal justice is possible, but only if Canadian criminal justice practices are altered to incorporate fundamental insights from Indigenous theories of justice. Chapter two surveys the failures of Canadian criminal justice for Indigenous people, including overincarceration, underrepresentation on juries, the epidemic of missing and murdered Indigenous women, and over- and under-policing. Drawing on Indigenous voices, I argue that these are symptoms of an underlying problem: the criminal justice system is not legitimate for Indigenous people. In the third chapter, I argue that the prominent liberal theories of legitimacy that undergird the Canadian polity cannot legitimate the Canadian constitutional framework or the institutions of criminal justice. Instead, criminal justice institutions must establish a form of freestanding legitimacy by deploying practices that themselves are acceptable to Indigenous people. In chapter four I make the case that a separate system of justice for Indigenous people cannot provide legitimacy. The lives of Indigenous and non-Indigenous Canadians are sufficiently intertwined that justice problems would inevitably cross jurisdictional boundaries (defined territorially or by identity), leaving many caught in the other system. In matters of justice, separation cannot obviate the need for reconciliation. In chapter five, I work to reconcile Indigenous and non-Indigenous understandings of a concept fundamental to Canadian justice: impartiality. I develop an inclusive model of impartiality implicit in Indigenous practices of circle justice that can supplement the Canadian model of impartiality as disinterestedness. In the conclusion, I note that the level of punitiveness of Canadian justice is unjustified, and a less punitive approach for all would open up more juridical and legal space for Indigenous approaches to justice.

Keywords: Criminal justice
Impartiality
Indigenous law
Legitimacy
Punishment
Reconciliation
Advisor: Williams, Melissa S
Iwasawa Theory of Fine Selmer Groups

Iwasawa theory began as a Galois module theory of ideal class groups, initiated by Kenkichi Iwasawa as part of the theory of cyclotomic fields. In the early 1970s, Barry Mazur considered generalizations of Iwasawa theory to Selmer groups of elliptic curves (Abelian varieties in general). At the turn of this century, Coates and Sujatha initiated the study of a subgroup of the Selmer group of an elliptic curve called the fine Selmer group. The focus of this thesis is to understand arithmetic properties of this subgroup. In particular, we understand the structure of fine Selmer groups and their growth patterns. We investigate a strong analogy between the growth of the p-rank of the fine Selmer group and the growth of the p-rank of the class groups. This is done in the classical Iwasawa theoretic setting of (multiple) Zp-extensions; but what is more striking is that this analogy can be extended to non-p-adic analytic extensions as well, where standard Iwasawa theoretic tools fail. Coates and Sujatha proposed two conjectures on the structure of the fine Selmer groups. Conjecture A is viewed as a generalization of the classical Iwasawa μ=0 conjecture to the context of the motive associated to an elliptic curve; whereas Conjecture B is in the spirit of generalising Greenberg's pseudonullity conjecture to elliptic curves. We provide new evidence towards these two conjectures.

Keywords: Fine Selmer Groups
Iwasawa Theory
Number Theory
Advisor: Murty, Kumar
Ramdorai, Sujatha
Essays on International Trade and Market Power

This thesis contains three papers exploring topics related to international trade and market power. In Chapter 1, I develop a quantitative model of international trade in which firms have endogenous market power in both product and labor markets that depends on their sizes in those markets. I use the model to evaluate the importance of accounting for oligopsony power on firm-level outcomes, welfare, the distribution of aggregate income, and the gains from trade. I calibrate the model to Indian plant-level data and import data for manufacturing sectors. I find that oligopsony causes small decreases in welfare but large decreases in aggregate real wages compared to perfect competition in labor markets. Trade increases large firms’ labor market power. Additionally, the welfare gains from trade are larger with oligopsony but the real wage gains from trade are smaller. Chapter 2, which is based on joint work with Stephen Ayerst, Faisal Ibrahim, and Swapnika Rachapalli, examines how technology embodied in traded goods generates spillovers across countries and sectors that increase aggregate growth. Using patent citation data from the United States, we construct a knowledge input output (IO) table and compare it to the production IO table. We use these IO structures and data on bilateral sector-level trade flows to measure embodied technology in imports. We show that increases in this measure are positively associated with increases in sectoral innovation expenditures. We build a quantitative model of firm-level innovation and trade with knowledge spillovers and calibrate it to trade and production data. We find that spillovers are an important contributor to growth, particularly in developing countries. Chapter 3 investigates how the strength of intellectual property rights affects firms’ make-or-buy decisions for specialized input purchases. I study a model of vertical integration and outsourcing in which a firm and an input supplier have asymmetric information about the supplier’s ability to use the firm’s knowledge capital outside of the relationship. I show that under outsourcing some relationships break down in equilibrium, which causes ex-post inefficiencies. When intellectual property rights are weak, increasing their strength may not reduce these inefficiencies unless the increase is large enough.

Keywords: International Trade
Advisor: Morrow, Peter
Parental Involvement in the Education of Their Adolescents with Attention-deficit Hyperactivity Disorder

The goal of this dissertation was to examine parent involvement in the education of their adolescent children with ADHD. The three studies were informed by aspects of two theoretical models (Hoover-Dempsey Sandler, 2005; Ryan Adams, 1995) that identify motivational and contextual factors that influence parental involvement, parent involvement behaviors, and parent and child factors that predict children’s academic achievement. Study 1 compared parents of adolescents with and without ADHD with regard to their involvement in their adolescents’ learning, study 2 explored the relationship between maternal and paternal self-efficacy and involvement behaviors with adolescents’ academic achievement, and study 3 examined the contribution of adolescents’ and mothers’ characteristics associated with maternal self-efficacy for supporting their adolescents’ learning. Method: The sample comprised 108 families with adolescents 13 to 18 years of age (58 ADHD, 50 non-ADHD). Parents reported on the psychological and contextual factors linked to their decision to become involved in their adolescents’ learning, their parental involvement behaviors, their parenting stress and their own ADHD symptoms. Adolescents reported on their perception of their parents’ involvement behaviors. Adolescents, their parents and teachers completed measures assessing adolescents’ inattention, hyperactivity-impulsivity, oppositional behaviors, learning problems, and academic achievement. Results: Both mothers and fathers of adolescents with ADHD reported lower self-efficacy to support their adolescents’ learning than parents of typically developing adolescents. Mothers of adolescents with ADHD, but not fathers, were less supportive of their adolescent children’s learning and had lower aspirations for their children than mothers of typically developing adolescents. Mothers’ self-efficacy and involvement behaviors did not predict adolescent academic achievement. Paternal self-efficacy, supportive involvement behaviors and aspirations were associated with higher academic achievement only in adolescents with ADHD. Mother-reported adolescent oppositional behaviors predicted maternal self-efficacy and this relationship was mediated by maternal parenting stress. The results partially support the theoretical models that informed the research. The findings highlight the role of parental self-efficacy. They suggest that fathers’ involvement in the learning of their adolescent children with ADHD is an important factor in enhancing the adolescents’ achievement, and that maternal involvement is influenced by their adolescents’ oppositional behaviors, their self-efficacy, and their parenting stress.

Keywords: achievement
ADHD
adolescents
parental involvement
parental self-efficacy
parenting stress
Advisor: Wiener, Judith
Numerical Model of Magnetostriction and Lorentz Force Mechanisms in Electromagnetic Acoustic Transducers

In this thesis, a successful development of a numerical model of magnetostriction and Lorentz force mechanisms in Electromagnetic Acoustic Transducers (EMATs) for nondestructive evaluation of steel components is presented. A Periodic Permanent Magnet Electromagnetic Acoustic Transducer (PPM-EMAT) scanner is designed and a prototype scanner is built for identifying corrosion defects that feature at least 20% wall-loss on ¼ "-thick mild steel plates. A sequence of experimental measurements is performed to evaluate the peak amplitude of the Shear Horizontal (SH) waves received from defect-free plates while the scanner moves in various directions on the surface of the sample plate. Scanner movement parallel to the direction of SH wave propagation led to an average of +/-20 % change in the received wave amplitude when the transmitter motion is towards/away from the receiver. This increase/decrease in amplitude remains intact even when scanner motion is stopped. Published models of PPM-EMAT transduction mechanisms are primarily focused on the Lorentz force coupling mechanism. These models ignore nonlinear magnetic behaviours of the steel samples and they cannot explain the source of asymmetrical coupling force distribution due to the scanner motion. A model is developed to evaluate the contribution of all transduction/reception mechanisms to the SH wave generation/reception of a stationary PPM-EMAT scanner operating on a mild steel plate. The PPM-EMAT transmitter, SH wave generation/propagation, and the PPM-EMAT receiver are modelled separately using a semi-analytical approach. The effects of the scanner motion are studied by including the magnetic hysteresis caused by the PPM array movement to the plate’s properties in the Finite Element Method (FEM) model of the magnetic fields. Model results demonstrated that the magnetostriction contribution to SH wave generation is approximately 55 % of the Lorentz mechanism for our EMAT configuration. The Lorentz mechanism is found to be insensitive to the scanner motion, while magnetostriction experiences a spatial displacement with respect to the Lorentz coupling mechanism in the transmitter EMAT. The new model results are consistent with the general behaviour of the experimental system.

Keywords: EMATs
Guided Ultrasonic Waves
Hysteresis
Loretnz
Magnetostriction
NDT
Advisor: Sinclair, Anthony N.
Filleter, Tobin
Mentoring Experiences of Black Female Public Secondary School Administrators in Southern Ontario, Canada

This study investigated the mentoring relationships experienced by Black female public secondary school principals and vice principals. I interviewed eight principals and eight vice principals from four school districts in Southern Ontario to obtain data on this topic. The data revealed that the participants’ mentoring experiences are varied and complex. Some participants’ mentoring experiences are positive, while others’ are not. The participants’ mentoring experiences vary partly due to the fact that most school districts do not provide systemic mentorship programmes for school administrators. Furthermore, as protégées, some participants in this study encountered additional challenges in comparison to those faced by female public secondary school administrators. Some of the challenges Black female administrators face are related to their low numbers within Southern Ontario school districts and the difficulty of finding homophilic mentors. Other challenges such as racial microaggressions occur due to their racialized identities within their school districts. For these challenges participants develop coping mechanisms such as assuming double consciousness as they navigate their working environments. The findings from this study shed light on the mentorship experiences of Black female public secondary school administrators, an area that has not been previously studied in Ontario. The findings will also add to the scarce extant literature on the mentorship of female public secondary school administrators. The data from this study generated some recommendations for mentorship of female public secondary school administrators and scope for future research.

Keywords: African Canadian/Black administrators
Black/African Canadian female principals
Black/African Canadian female public school administrators
Black/AfricanCanadian female vice principals
Double consciousness
Mentorship
Advisor: Ryan, James (Jim)