VictorJuiz/thesis huggingface dataset:
Analysis and Design of Hybrid Divided Power Converters
Keywords: Current Balancing
Hybrid Converter Topologies
LED Lighting
Power Division
Power Electronics
Switched Capacitor Converters

In this thesis, we report a design methodology for the combination of switched-capacitor (SC) and conventional inductive switch-mode power supplies (SMPS) into new power converters, so-called Hybrid Divided-Power (HDP) converters. These converters present an opportunity to reduce volume while also increasing power processing efficiency by utilizing the increased power density of SC converters and parallelizing power processing to reduce both passive volume and switch blocking voltage. The thesis places these converters in the emerging field of hybrid power converters, a class of converters which combine SC converters and conventional inductive converters. The main results include a switched capacitor converter design methodology based on efficiency and ripple requirements and the principle of operation and design of HDP converters. Two novel converters based on the stacked HDP configuration for LED driving applications are shown. The design of a third novel converter based on the differential HDP configuration is also shown. This differential HDP converter is a multiple output LED driver for mobile applications. A current balancing technique based on charge matching is developed for the converter. Practical experimental results from these novel topologies confirm reduction in passive volume around 70% compared to conventional topologies while also increasing efficiency over the whole range. In particular light-load efficiency is improved up to 20%. The efficacy of the charge matching control presented in this thesis is confirmed through simulation results, achieving matching within 2% over the operating range. This work indicates that HDP converters are a promising new class of converters to investigate.
Semi-autonomous Control of Multi-robot Teams in Urban Search and Rescue Applications
Keywords: Machine Learning
Multi-Robot Systems
Semi-Autonomous Control
Supervisory Control
Urban Search and Rescue

Urban search and rescue (USAR) has been a significant application in robotics because the deployment of rescue robots in these life-risking tasks can help reduce the personal risks of human rescue workers and increase the speed of emergency response. Furthermore, the incorporation of multi-robot rescue teams consisting of a group of heterogeneous rescue robots is advantageous since it allows shorter robot deployment times, provides situational awareness from multiple locations, and introduces redundancy and fault-tolerance to this time-critical mission. While promising, the control of multi-robot rescue teams is a challenging task. In particular, decisions need to be made regarding which rescue tasks should be executed and by which robot in a specific scenario. This thesis focuses on the development of semi-autonomous control architectures for multi-robot USAR teams in order to address the challenges in human-robot coordination and multi-robot cooperation in USAR applications. A learning-based semi-autonomous control architecture is developed for multi-robot teams in USAR environments, allowing a team of rescue robots to learn and make decisions regarding which rescue tasks need to be carried out at a given time. The task sharing between rescue robots and human operators can reduce the stress and mental workload of the operators, while allowing rescue robots to benefit from a human operator’s experience and knowledge. Furthermore, the cooperation between different rescue robots enables fast exploration of cluttered USAR scenes by minimizing overlap or repeated revisits of an explored area, as well as improve the reliability of the overall search and rescue mission. This thesis further addresses the high-level task allocation challenge for a large heterogeneous multi-robot team. A hierarchical supervisory control architecture is proposed allowing effective task sharing amongst the multi-robot team based on the dimension, mobility and sensing capabilities of individual robots. The developed approach can also handle the changes to team size due to robot failures and the need for robot repair during a USAR mission. The developed multi-robot task allocation approach allows a single operator to control a large team of heterogeneous rescue robots in USAR applications. Simulations and experiments in simulated USAR environments verified the performance of the proposed supervisory controller.
Dynamic Inventory Optimization with Learning and Model Ambiguity
Keywords: Bayesian dynamic programming
Bayesian learning
inventory management

Classic inventory control problems typically assume that the demand distribution is known a priori. In reality, this assumption is not always satisfied. Motivated by this concern, the joint optimization of learning and control is studied. We first consider the situation where parameters of the demand distribution are not known a priori, but need to be learned using right-censored sales data. A Bayesian framework is adopted for demand learning and the corresponding control problem is analyzed via Bayesian dynamic programming (BDP). Structural results of the optimal policy are established. In particular, we show that the BDP-optimal decisions can be expressed as the sum of a myopic-optimal decision plus a non-negative exploration boost which is proportional to the posterior index of dispersion of the unknown mean demand. This structure clearly articulates the manner in which the statistical learning and inventory control are jointly optimized. Next, we study an optimal inventory control problem in the presence of model miss-specification. In this problem, decision makers account for the miss-specification via solving a worst-case problem against an adversary, ``nature", who has the ability to alter the underlying demand distribution so as to minimize the decision maker's expected reward. We show that the decision maker's robust-optimal decisions are bounded above by the optimal solutions of the nominal model. This structural result clearly explains the trade-off between optimization and risk aversion. In the last chapter, we attempt to incorporate the elements of the Bayesian and robust approaches, namely robust Bayesian optimization. In particular, we are interested in how decision makers can remain robust to model uncertainty while also learning at the same time. We establish an analytical upper bound of the decision maker's optimal decisions, which can be expressed as the sum of a myopic-optimal decision plus an exploration boost and minus a risk aversion adjustment. We then propose a heuristic which is based on the approximation of the first order optimality condition, and the effort of computing this heuristic solution is essentially equal to obtain the robust-optimal and BDP-optimal solutions separately.
Representations of Psychological Distress Among Canadian Muslims of South Asian Origin: A Qualitative Study using the Self-regulatory Model
Keywords: counselling
illness representations
Islam
phenomenology
psychotherapy
self-regulatory model

This study sought to gain insight into representations of distress among Canadian Muslims of South Asian origin. It sought to examine whether representations of distress among this population are influenced by Islamic, scientific, and Western representations, the extent to which they differ from those assumed in the prevailing literature on Islamic healing, counselling, psychotherapy, and psychiatry with Muslim populations, and whether individuals attempt to incorporate multiple influences into a single coherent representation, or they construct multiple representations simultaneously. The Self-Regulatory Model of Illness Representation (Leventhal, Brissette Leventhal, 2003) was utilized to understand how the participants made sense of, emotionally responded to, and coped with their experiences of distress. The findings of this study indicated that a common theme among the participants was the belief that their distress was a form of punishment from God due to lack of faith or piety, thereby suggesting a significant religious aspect to their representations of distress. Paradoxically, the participants attempted to cope with their distress through counselling and psychotherapy or pharmacotherapy, which implies an equally strong biomedical aspect to their representations of distress. Reasons for this dual and possibly contradictory nature of participants’ representations of distress are discussed along with the implications of the findings for counselling and psychotherapy.
Directed Migration Achieved in Mammalian Cells via Ca2+ Signal Rewiring in Synthetic Protein Chimeras
Keywords: calcium signaling
chimeras
nano bodies
synthetic biology
TNF alpha
VEGFR2

Synthetic biology achieves control over cellular behavior by endogenous re-wiring. Ca2+ signals allow cells to regulate diverse processes such as migration, apoptosis, motility and exocytosis. In some receptors (e.g. VEGFR2), Ca2+ signals are generated upon ligand binding (e.g. VEGF-A). Here, firstly we engineered fusion proteins that generate a Ca2+ signal upon ligand binding by creating fusions of domains that oligomerize to the transmembrane domain and the cytoplasmic tail of the VEGFR2. By coupling these chimeric proteins that generate Ca2+ signals with proteins that respond to Ca2+ signals, we re-wired, for example, dynamic cellular blebbing to increases in extracellular free Ca2+. Next, we validated this design strategy in two systems, i.e., inflammatory cytokines such as TNFα and antibodies. A system of proteins was used: an engineered TNFα chimeric receptor (named TNFR1chi), a previously engineered Ca2+-activated RhoA (named CaRQ), VSVG and thymidine kinase. Upon binding TNFα, TNFR1chi generates a Ca2+ signal that in turn activates CaRQ-mediated non-apoptotic blebs allowing migration towards the TNFα source. Next, the addition of VSVG, upon low pH induction, causes membrane fusion of the engineered and TNFα source cells. Finally, post-ganciclovir treatment, cells undergo death via the thymidine kinase suicide mechanism. Hence, this forms the basis of engineering a cell to target inflammatory disease sites characterized by TNFα secretion and a low pH microenvironment. Lastly, we exploited antibodies to bind their antigens exclusively in combination with the ability of the cytoplasmic domain of VEGFR2 to generate a Ca2+ signal upon oligomerization. Using protein fusions between antibody variants (i.e. nanobody, single-chain antibody and the monoclonal antibody) and the VEGFR2 cytoplasmic domain, Ca2+ signals were generated in response to extracellular stimulation with green fluorescent protein, mCherry, tumour necrosis factor alpha and soluble CD14. The Ca2+ signal generation by the stimulus did not require a stringent transition from monomer to oligomer state but instead, only required an increase in the oligomeric state. The Ca2+ signal generated by these classes of antibody-based fusion proteins can be rewired with a Ca2+ indicator or with an engineered Ca2+ activated RhoA to allow for antigen screening or migration to most extracellular ligands, respectively.
Complex Dynamics of Exploited Populations: Tipping Points, Instability, and Phenological Diversity
Keywords: Adopted migrant life history
Daphnia magna
Modeling
Pacific herring
Population ecology

Understanding the consequences of complex population dynamics for population persistence, ecosystem functioning, and wildlife management is vital as our biosphere becomes increasingly shaped by anthropogenic change. Exploited populations are commonly recognized to exhibit complex population dynamics, which often affect the harvest of economic and culturally important species. How social learning, harvest, and population diversity shape population dynamics are not well understood, and I therefore undertook studies to investigate their effects. (1) I developed novel theory to assess the population dynamic consequences of migratory homing acquired via social learning, called the adopted migrant life history. Simple mechanistic assumptions led to dynamical behaviours ranging from stable coexistence of local populations to local extirpations, depending on the encounter potential between dispersing juveniles and migrating adults. Local populations were especially vulnerable under unequal adult survival, suggesting that uneven harvest pressure could exacerbate the risk of local collapses that are difficult to reverse. (2) I verified that harvest can increase temporal variability in the abundance of exploited populations by analyzing a harvest experiment on Daphnia magna. Harvest elevated population variability by amplifying deterministic nonlinear dynamics rather than increasing the effect of environmental stochasticity alone. This implies high short-term predictability but also the possibilities of oscillations, tipping points, and hysteresis. (3) I identified a large contraction in Pacific herring spawning phenology between 1951 and 2016 in British Columbia, Canada. Herring are a vital forage fish in northeast Pacific food webs, and support fisheries both directly and indirectly. The contraction represents a type of population diversity loss, which may impact population stability via erosion of portfolio effects. My results show the dynamic consequences of social learning and harvest, and identify a population diversity decline in an important forage fish. Together these results open a new perspective on complex population dynamics in exploited populations.
Cross-cultural Differences in Lie-telling and Truth-telling Surrounding Sporting Events
Keywords: Acculturation
Cross-cultural differences
Moral Behaviour
Moral Judgments
Sporting events

Sporting events receive international recognition and athletes are typically held to higher moral standards. However, when athletes engage in questionable moral behaviour all cultures may not evaluate this behaviour similarly or support their athletes similarly. This study investigated emerging adults’ moral rationalizations of fabricated scenario-based sporting events where an athlete engaged in questionable moral behaviour, such as taking performance-enhancing drugs, and the protagonist either told a lie and helped the athlete or told the truth and harmed the athlete. Scenarios incorporated different collectives where either athletes were representing their country or themselves as individuals. Emerging adults from North America and China were asked to evaluate the protagonist’s actions and indicate what behaviour they themselves would opt to engage in. With the continued increase in immigration to Western countries, acculturation was considered through comparisons between two North American ethnicities, Caucasian and Asian. Cultural trends have been established in previous research where children and adolescents from Eastern cultures evaluate lie-telling more positively when protecting a larger group collective, such as a country, whereas children and adolescents from Western cultures evaluate lie-telling more positively when protecting a smaller collective, such as an individual or themselves (Dmytro, Lo, O’Leary, Fu, Lee, Cameron, 2014; Fu, Evans, Wang, Lee, 2008; Fu, Luo, Heyman, Wang, Cameron, Lee, 2016; Fu, Xu, Cameron, Heyman, Lee, 2007; Xu, Bao, Fu, Talwar, Lee, 2010). These trends are mirrored with regards to engagement in lie-telling. Similar cultural trends were found within the current study’s emerging adult population and when utilizing scenarios with more severe consequences. Emerging adults from China illustrated greater loyalty for the athlete when representing their country, whereas emerging adults from North America illustrated greater loyalty for the athlete when representing themselves. When ethnicity was considered it was surprising to find that North American Asian emerging adults’ moral rationalizations were more similar to North American Caucasian emerging adults’ moral rationalizations rather than to emerging adults from China. These findings support theories of cross-cultural differences and highlight the blending and integration of cultures in North America.
Rising from Below: The Families of Roman Municipal Freedmen and Social Mobility in the Roman Empire
Keywords: Municipal freedmen
Municipal slaves
Roman Empire
Roman families
Roman slavery
Social mobility

This dissertation provides the first combined analysis of how Roman municipal freedmen and their descendants navigated the social, economic, and political landscape of imperial society. The municipal freedmen (liberti publici) had been owned and manumitted by towns in Italy, where they constituted the familia publica and performed many day-to-day functions for the municipal administration. They are not to be confused with freedmen of private individuals of local origin. Their status is often assumed to have conferred on the freedmen and their descendants a high degree of prestige that helped to advance their careers. The study first addresses two demographic issues in order to estimate the volume of municipal freedmen and descendants one can expect to document in the epigraphic record. A heterogeneous approach is employed to argue that the familia publica in most towns was small. The practice of manumitting slaves in the familia is also reconstructed in light of universal practices observed in other slave households. I propose that towns tended to be cautious in manumitting their slaves, especially those with technical skills. Next, the evidence for the municipal freedmen is analyzed. While some had the opportunity to forge links to the municipal elite and accumulate a large peculium that enhanced their social capital, they also lacked a personal patron whose financial backing and connections would have provided a push up the social ladder after manumission. Only a limited number of the freedmen known to us achieved any meaningful social or economic advancement. It is suggested that the lack of a patron made it difficult for most freedmen to break away from the familia publica and enter into other spheres of the local economy and social hierarchy. The study concludes by analyzing the activities of the municipal freedmen’s descendants across multiple generations. They, too, experienced only marginal success. A small number ascended to the senatorial or equestrian order or the ranks of the municipal elite, and another narrow segment joined local occupational and voluntary associations. Yet the vast majority never advanced socially or economically and are known to us as little more than a name on an epitaph.
Ebla’s Hegemony and Its Impact on the Archaeology of the Amuq Plain in the Third Millennium BCE
Keywords: Amuq
Archaeology
Bronze Age
Ebla
Hegemony
Syria

This dissertation investigates the emergence of Ebla as a regional state in northwest Syria during the Early Bronze Age and provides a characterization of Ebla that emphasizes its hegemonic rather than imperial features. The texts recovered from the Royal Palace G archives reveal that Ebla expanded from a small Ciseuphratean kingdom into a major regional power in Upper Mesopotamia over the course of just four or five decades. To consolidate and maintain its rapidly growing periphery, Ebla engaged in intensive diplomatic relations with an array of client states, semi-autonomous polities, and independent kingdoms. Often, political goals were achieved through mutual gift-exchange and interdynastic marriage, but military activity became increasingly common towards the end of the period covered by the texts. However, apart from installing palace officials at some cities, Ebla did not appear to have invested heavily in building infrastructure, such as roads or forts, along its periphery, preferring instead to leave matters of defense up to client and allied states. As a result, the archaeological impact of Ebla’s political hegemony along parts of its periphery was minimal. In re-evaluating the archaeological evidence for Ebla’s growth in the mid-third millennium BCE, this dissertation shows that in only a few instances—for example, in changes to regional settlement patterns in the Amuq Plain, subsistence strategies at Tell es-Sweyhat, and the distribution of ceramic assemblages—can an Eblaite influence on material culture along its periphery be inferred, and even then, only indirectly. While Ebla’s sphere of interaction extended over a considerable territory, this dissertation restricts most of its discussion to Ebla’s northwestern frontier, and particularly to the archaeology of the Amuq Plain. This study demonstrates that even though Ebla had installed an official at Alalaḫu—the major polity in the Amuq Plain—local historical trajectories remained largely intact, and Ebla’s hegemony left only an ephemeral archaeological legacy in the area.
Drugs, Pharmacy, Healing Rites, and Ethnobotany: Therapeutic Writing in the Foundational Narratives of Puerto Rico and the Dominican Republic
Keywords: Afro-Dominican
drugs
ethnobotany
pharmacopoeia
pharmacy and gender
spirituality

Foundational narratives from the Hispanic Caribbean were involved in projects of political modernization and relied on stylistic novelty and political disagreement. Turn-of-the-century Puerto Rican and Dominican intellectuals prioritized three areas of political modernization—decolonization, emancipation of women, and some sort of racial justice. They looked at pharmacy for ways of structuring their literary imagination and proposed psychoactive writing to boost agency. My dissertation relates their approaches to pharmacy to their political goals. Eugenio María de Hostos abandoned the politics of harmonization and invested in narco-analysis to make colonial traumas accessible to the reader on the cognitive and emotional level. Hostos required stimulants to counteract inertia of the colonial subject and to disclose the implication of Creole elites, like himself, in the hegemonic regime. I connect his psychoactive writing and its effects on the body to the post-Hegelian dialectic theorized by Nietzsche and Jean-Luc Nancy. From a comparably elitist perspective, Amelia Francasci sought to legitimize her work by suggesting parallels with the institution of pharmacy, consistently suspect of quackery at the turn of the century. I claim that Francasci opposed the discourse of the sick woman. I frame her pharmaco-writing within global feminist struggles to regain access to pharmacy, for which I build on Larry Duffy’s study of the nineteenth-century institutional transformations of chemistry and pharmacy in France and examine their repercussions in Haiti and the Dominican Republic. Two other writers I interpret—Francisco Gregorio Billini and Federico García Godoy—were more directly involved in Dominican politics and the state apparatus. They attempted to resolve what they perceived as national problems by assuaging racial tensions while exacerbating ethnic differences with Haiti. Billini and García Godoy incorporated Afro-Dominican healing rites into the national imagery yet misattributed them to European folklore. I suggest that such cultural appropriation of Afro-indigenous ethnobotany devalued Afro-indigenous connections.