VictorJuiz/thesis huggingface dataset:
Maintenance Optimization of Partially Observable Complex Systems

Maintenance is an essential activity to improve the productivity of deteriorating systems. Various technical issues arise during the development of optimal maintenance policies. Two of the most commonly encountered issues are \emph{partial information} and \emph{high dimensionality}. Firstly, information obtained from condition monitoring sensors is inherently noisy, meaning that decision makers must plan maintenance interventions under uncertainty about the true operational state of the system. Secondly, a high dimensional state representation is necessary for modeling real world systems, e.g. those characterized by complex deterioration mechanisms or those composed of multiple subsystems, adding another layer of complexity to maintenance decision making. This thesis develops three related models reflecting the importance of partial information and high dimensionality in maintenance optimization. The first model concerns the preventive maintenance of a single-unit system such as a wind turbine. We model the system's deterioration as a continuous-time Markov chain with two unobservable operational states and one observable failure state. Our objective is to jointly decide when to collect condition monitoring data and when to initiate preventive maintenance. We first develop the Bayesian updating of the posterior probability that the system is in a bad operational state, and then formulate an optimal stopping problem to characterize the optimal policy. Specifically, we prove via dynamic programming arguments that the optimal policy has a threshold structure, enabling its implementation using the familiar control chart. For the second model, we study the group maintenance of a multi-unit system such as a wind farm. We analyze and compute the optimal policy prescribing when to initiate group maintenance interventions, assuming full observability of each unit in the system, and construct a heuristic policy for the computationally intractable setting with partially observable units. Lastly, the third model considers the resource-constrained maintenance of a large-scale system, e.g. a system of geographically dispersed wind farms. Sequential allocation of the limited repair resources corresponds to a restless bandits problem, which we near-optimally solve using Whittle's index policy. Efficient algorithms are developed for computing the proposed maintenance policies. Also, the extension to deterioration processes with multiple operational states is discussed for each of the three models.

Advisor: Makis, Viliam
History and Literature Interwoven yet Distinct: The Paşanāme, a Seventeenth-century Ottoman Turkish Mes̠nevī on Conflicts in Rumelia and the Northern Black Sea Region

The Paşanāme is a 2180-couplet Ottoman Turkish mes̠nevī that, in my assessment, represents the continuation of the ġazānāme genre in evolved form during the first half of the seventeenth century. The work is by Ṭulūʿī, an Ottoman court poet patronized by Murād IV (r. 1623–40). It primarily consists of accounts of two campaigns led by the vizier Kenʿān Paşa. Kenʿān Paşa was appointed in the 1620s first on an expedition to restore imperial authority in parts of Rumelia, and later to campaign in the northern Black Sea region against the Crimean Tatar prince Şāhīn Giray, a Polish-Lithunian army under the command of Chmielecki (Meleşki), and parties of Cossacks. This thesis argues for an integrated historico-literary approach to understanding the genre of work and the type of primary source that the Paşanāme represents. Chapter 1 preliminarily assesses the historicity of the accounts of events in the Paşanāme. Relevant historical sources are cross-referenced; they include the Feẕleke of Kātib Çelebī, the Tārīḫ-i Naʿīmā, the Topçular Kātibi ʿAbd ul-Qādīr Efendi Tārīḫi, decrees in the mühimme defteri, and the Seyāhatnāme of Evliyā Çelebī. To better understand the Paşanāme holistically, Chapter 2 is devoted to examining the specific places in the work where Ṭulūʿī concentrates his display of literary/poetic skills, which were intended to enhance the overall narrative, but not to substitute the central goal of relating past events. In Chapter 3, a full transcription and translation of the Paşanāme is provided, so that more readers/researchers can decide for themselves how to understand the work.

Keywords: Cossacks
Gazavatname
Ottoman history
Ottoman literature
Rumelia and Black Sea history
Turkish literature
Advisor: Ostapchuk, Victor
An Aesthetics of Endurance: Art, Visual Culture and Indigenous Presence in Nagaland, India

This doctoral dissertation explores objects of Indigenous art and visual culture in Nagaland, northeast India as sites of emergence informed by a temporally layered Indigenous present that foreground the aesthetics of endurance that characterizes Indigenous lifeworlds and their settler-colonial marginalization by the postcolonial state in contemporary South Asia. It is based on ethnographic interviews with regional artists and activists, and visual analysis of objects as sites that world multiple conceptions of time and space, associated with the ever-changing practices of Naga Indigeneity and with discursive understandings of them, in layered ways. The primary objects of my research—craft objects, memorial monuments, and house museums—were produced in the predominantly Indigenous and Christian Nagaland after 1997. This was when an armed, pan-Indigenous, transregional and transnational Naga movement for political autonomy, which began in 1953, ended with a ceasefire agreement between the Indian government and Naga nationalists. I argue that the plural and layered temporality of the objects materialize intersubjective conceptions of time and space constituted by Indigenous practices, relationships to land, and their overlapping re-significations as heritage within the terms of culture, and as history, statecraft, sovereignty, and Indigenous rights within the terms of democracy. It also grounds the newness of the monument, the museum and craft object, which shows the aesthetics of endurance to be a space of emergence as well. This highlights an Indigenous present co-constituted by Indigenous rituals and Christian practices, forms of collective memory, and the contestations that characterize them, which illuminate regional processes of identity-formation. Based on discursive analyses of colonial and post-independence scholarship, this thesis also shows that the institutionalization of Indigenous arts as India’s “tribal” crafts both essentializes them and appropriates them to Hindu hegemonic notions of craft and culture. This reveals the art historical lineage of the postcolonial Indian state’s settler-colonial logic of the marginalization of regional Indigenous lifeworlds. The layered nature of my objects exemplifies the enduring and emergent qualities of Indigenous presence in the face of this ongoing discursive appropriation, while also exemplifying the plural and layered temporality of art as such and the present that we all inhabit.

Keywords: Aesthetics
Art
Indigeneity
Politics
South Asia
Visual Culture
Advisor: Jain, Kajri
The Neoliberal Politics of Queer Men of Colour’s Erotic Lives

The growth of queer digital spaces that offer queer men of colour the ability to find each other for sex and dating has produced a set of challenges for researchers. While these spaces are seen as significant for opening up new erotic sites, they are simultaneously mired by erotic practices rooted in racism. This dissertation asks, what significant ways do racial differences play a role in queer men of colour’s erotic lives, particularly in the digital era, and what kind of agency do queer men of colour practice in regard to erotic racism? I argue that despite evidence of increasing racism in digital spaces, queer men of colour continue to navigate, (re)shape and participate in online discourses including even those considered ideologically problematic. My project undertakes an in-depth study of the practices and experiences of queer men of colour to better understand how racial difference and configurations of neoliberalism shape queer men of colour’s intimate lives. Based on interview data, this dissertation demonstrates that many queer men of colour, including those who see themselves as anti-racist, are often erotically attached to what I characterize as racial and neoliberal economies of desirability. Racial and neoliberal economies of desirability refer to preferences for particular forms of (economic and cultural) capital rooted within white middle-class ideals. This dissertation focuses on racism within quotidian (erotic) practices in order to understand the depth through which racial difference organizes our intimate lives. My analysis builds from the theoretical framework of queer of colo(u)r critique to explore how queer erotic lives are sutured to intersecting configurations of gender, sexuality, race, capital, nation and disability/normalcy. Extending queer of colour critique theorizations of power differentials between differently racialized groups and within each community of colour, I theorize eroticized power relations that exist between queer men of colour. My research underscores that queer men of colour’s erotic attachments often align with sexual and gendered racial discourses while they are simultaneously committed to anti-racist and often feminist politics. By underscoring this point, this research provides new ways of understanding queer subjectivities as vexing and contradictory, because in reality there are no ‘perfectly’ non-racist subjects.

Keywords: erotic agency
erotic racism
neoliberalism
queer erotics
queer of colour critique
women of colour feminism
Advisor: Trotz, Alissa
Yoneyama, Lisa
"The Motive for Metaphor": Metaphor and Imagination in Moses ibn Ezra, Judah Halevi, Moses Maimonides and Shem Tov ibn Falaquera

This thesis seeks to challenge assumptions that posit imagination as the opposite of intellect, and argues that the complexities of epistemology require a nuanced, rather than binary, approach to imagination. By exploring metaphor and imagination in medieval Arabic-Aristotelian and Jewish thought, my work examines how metaphoric language creates conceptual figurations that require imagination to unravel their meaning. Although imagination is a necessary contributor to abstract thought, and Andalusī thinkers writing in Arabic highlight the difference between the faculty of imagination and its functions, this aspect of human psychology has not been transmitted through translations and across borders. A metaphor is a word picture; it presents a semantic association that requires deciphering. Ibn Ezra, Halevi and Maimonides discuss the ramifications of using likenesses to describe the unknowable divine. Chapter 1 considers the cognitive aspect of metaphor in light of Arabic-Aristotelian poetics and modern metaphor studies. In order to comprehend how metaphor operates at the level of human understanding, Chapter 2 undertakes an analysis of medieval Jewish engagement with Fārābīan and Avicennan psychology. Both Halevi and Maimonides operate within the Arabic-Aristotelian paradigm; however, imagination plays different, yet vital, roles in the theology of each Jewish thinker. Chapter 3 focuses on terms used to describe imagination in Maimonides’ Guide of the Perplexed, and discusses how these terms have been translated into Hebrew, English and French. Using translation theory, this chapter calls into question the translators’ precision in transmitting the Judeo-Arabic terms into the target language. Chapter 4 draws connections between Iberian thinker and poet Falaquera and his Andalusī predecessors. Falaquera maintains a binary approach to imagination and intellect in his translation of Maimonides’ Guide. His critique of the falsity of figurative language is examined in light of the poetic theories of Christian scholastics, who advocate an ethical role for poetry. This thesis highlights the cognitive aspect of metaphoric language, rehabilitates imagination’s vital role in human psychology, and highlights a nuanced approach to imagination that is lost on Maimonides’ interpreters. Its significance lies in the examination of medieval Jewish thought in relation to both Islamo-Arabic and Christian Scholastic traditions.

Keywords: Cognition and Understanding
Figurative Language and Poetry
Judeo-Arabic
Psychology
Translation
Advisor: Ross, Jill
Effects of Puberty and Obesity on Central Nervous System Autoimmunity in Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic neuroinflammatory disease that is characterized by the formation of inflammatory demyelinating lesions in the central nervous system (CNS) white matter. One of the largest risk factors for developing MS is being female. The female preponderance of MS only manifests post-puberty implicating hormonal factors in this biology. Several other MS risk factors including obesity only impact MS risk when experienced post-puberty. The mechanisms of how puberty and obesity enhance MS risk are unknown. This thesis aimed to investigate how puberty in females (Chapter 2) and adolescent obesity (Chapter 3) increase autoimmune susceptibility in the mouse model of MS, experimental autoimmune encephalomyelitis (EAE). First, EAE development was compared between age-matched SJL/J mice that differed only by pubertal status. It was observed that puberty in females, but not males, was associated with increased susceptibility to EAE. Additional studies performed in female mice revealed that myelin-specific T helper (Th) cell responses were more robust post-puberty as a result of more efficient antigen-presenting cell (APC) function. These findings suggest that the female adaptive immune system matures with puberty. In Chapter 3, we evaluated the effect of diet-induced obesity (DIO) on the development of EAE in adolescent female and male C57BL/6J mice. We observed that short-term (3-4 weeks) exposure to high-fat diet starting at 6 weeks of age resulted in modest weight gain in both sexes. Upon induction of EAE, mice on high-fat diet developed more severe EAE; this effect was particularly striking in female mice. Further studies performed in diseased mice revealed that DIO increased the number of myelin-specific and CD44hi Th cells in mice of both sexes but had the unique effect of enhancing Th1 responses in females. DIO also increased the potential of naïve CD4+ T cells from non-immunized mice to secrete IFN-γ in response to anti-CD3 and anti-CD28. This effect was more prominent in female CD4+ T cells and was associated with upregulation of IFN-γ-induced STAT1 signaling. Together, these studies contribute to the understanding of how puberty and adolescent obesity enhance CNS autoimmune susceptibility in females.

Keywords: autoimmunity
diet-induced obesity
puberty
Advisor: Dunn, Shannon E
Studies on the Evolution of and Mutational Processes Driving Childhood Cancer in the Context of Genetic Predisposition

Cancer predisposition syndromes (CPSs) are caused by heritable mutations, often affecting DNA-repair pathways, which dramatically increase cancer risk. Once diagnosed, screening of additional family members combined with cancer surveillance protocols have shown significant survival benefits. However, CPSs are largely underdiagnosed due to clinical heterogeneity and variants of uncertain significance. In this thesis I explore the hypothesis that CPS-associated cancers exhibit characteristic DNA-repair-associated mutational signatures—patterns of somatic mutation related to mutation aetiology¬— and/or evolutionary dynamics, which may be exploited to aid in CPS diagnosis and management. To address this hypothesis, I studied two model CPSs—constitutional mismatch repair deficiency (CMMRD) and Li-Fraumeni syndrome (LFS). CMMRD results from biallelic germline mutations in one of four mismatch repair genes, and is associated with childhood brain, colorectal and lymphocytic neoplasms. Recent work has shown cancers developing in CMMRD patients to possess recurrent somatic mutations in POLE/POLD1 and massively elevated numbers of somatic point mutations (hypermutation). To assess the frequency, timing, and aetiology of hypermutation in adult and childhood cancer, I performed a comprehensive analysis of hypermutation across >80,000 human cancers. Our work identified CMMRD in 15 patients, resulting in their enrollment on a surveillance protocol and immune checkpoint inhibitor trial, which has shown sustained responses for CMMRD patients. Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome caused by germline mutations in the TP53 tumor suppressor gene, and is associated with a wide range of cancers, including sarcomas, breast cancers, adrenocortical carcinomas and brain tumours. To investigate somatic mutational events driving tumourigenesis in LFS, I performed whole-genome sequencing (WGS) analysis of bulk and multi-region dissections of tumours derived from childhood and young adult patients with germline TP53 mutations. Our analyses revealed that the life history of LFS cancers is marked by early loss of heterozygosity of TP53, mutational signatures related to homologous recombination repair deficiency and in some cases previous chemotherapeutic treatment. In summary, my thesis research demonstrated CPS-related malignancies are often mutationally and evolutionarily distinct entities. The unique molecular features of these tumours reveal aspects of their aetiology and in some cases can be used to aid in diagnosing and treating these patients.

Advisor: Malkin, David
Shlien, Adam
Molecular Parameters of Crumbs Surface Stability and Cytoplasmic Interactions in Epithelial Polarity

Epithelial integrity is essential for development and morphogenesis and relies critically on the polar organization of individual epithelial cells. The Crumbs (Crb) complex of proteins is a key regulator of epithelial apical-basal polarity, apical membrane size, and assembly of adherens junctions. The apical transmembrane protein Crb has two conserved cytoplasmic protein interaction motifs, a FERM domain binding motif (FDB) and a PDZ binding motif (PDB), which are crucial for its function. Crb FDB can be phosphorylated by the apical kinase aPKC, but the consequences of Crb phosphorylation remain largely unknown. Moreover, increasing evidence suggest that the large extracellular region of Crb plays a role in Crb surface stability and distribution. In developing and analyzing a new set of Crb mutant constructs I found that Crb surface stability requires both its extra- and intracellular regions. Furthermore, both Crb FDB and PDB motifs contribute to surface stability and Crb function. Also, mutations of potential ubiquitination sites in the Crb cytoplasmic tail cause a dramatic increase in Crb accumulation, suggesting that Crb turnover requires ubiquitination-dependent endocytosis. I also investigated Crb phosphomutant constructs. My findings suggest that lack of phosphorylation of the Crb FDB is compatible with normal development confirming published findings. However, I also show that phosphorylation of the Crb FDB enhances Crb membrane accumulation and activity. In studying the effects of Crb phosphorylation on two FERM proteins Crb FDB binding partners, Moesin and Yurt, I found that any modification in Crb phosphorylation strongly reduces cortical Moesin, and dramatically decreases its sensitivity to the negative regulatory effects of Yurt as well as reduces the levels of active Yurt. Additionally, Crb phosphorylation causes a reduction of aPKC as a potential negative feedback mechanism. Taken together, I developed new insight into how Crb levels and activity are regulated at the apical membrane, and the complex relationships between, Crb, Yurt, aPKC, and Moesin.

Keywords: aPKC
Crumbs
Drosophila
Epithelial Polarity
Phosphorylation
Yurt
Advisor: Tepass, Ulrich
Examining Social Exclusion by ‘Race’/Ethnicity in Toronto’s Health Care System: A Scientific Realist-inspired Concept Mapping Study

With widening health inequities, developing an effective policy of action requires a better understanding of the mechanisms through which health inequities are distributed. The purpose of this doctoral research is to understand the effect of current hospital policies and practices on racial/ethnic groups at the level of the individual in Toronto’s health care system. The overall goal is to provide the explanatory power necessary to change policies and practices. Using concept mapping, a semi-qualitative study design, participants identified experiences of social exclusion when receiving health care in Toronto’s health care system. A political economy theory with a scientific realist philosophy of science was used to identify social causal mechanisms and explain how and why everyday racism occurs in Toronto’s health care setting. From the brainstorming activity, participants generated 35 unique statements of ways in which patients feel disrespect and mistreatment when receiving health care. From the sorting and mapping activity, statements were grouped into five clusters: ‘Racial/ethnic and class discrimination’, ‘Dehumanizing the patient’, ‘Negligent communication’, ‘Professional misconduct’, and ‘Unequal access to health and health services’. Two distinct conceptual regions of social exclusion were identified: ‘Viewed as inferior’ and ‘Unequal medical access’. Clusters rated highly for ‘race’/ethnic based discrimination were ‘Racial/ethnic and class discrimination’ and ‘Dehumanizing the patient’. Racialized health care users reported ‘race’/ethnic based discrimination or everyday racism as largely contributing to the challenges experienced when receiving health care. From the go-zone data, statements rated high for ‘race’/ethnic based discrimination and taking action/change were ‘when the patient's symptoms are ignored or not taken seriously’, ‘when the health care provider does not provide the requested information’, and ‘when the health care provider belittles or talks down to the patient’. To eliminate institutional racism, political will is needed to eliminate the ideology of racial inferiority often used for the purpose of justifying racist actions/unequal treatment. Anti-racist policies are needed to move beyond cultural competence polices and towards addressing the centrality of unequal power relations and everyday racism in health care. This has implications for nursing leadership, health care provider education, health care organizations, and health care practice.

Keywords: Health care
Health inequities
Policy
Racism
Realism
Social determinants of health
Advisor: Muntaner, Carles
Children's Attitudinal and Behavioural Explicit Racial Bias and Its Reduction

This thesis explored the reduction of children’s intergroup bias. Part one of the thesis tested whether a multiethnic sample of Canadian children aged 4-12 years showed explicit preference for white over black race in their trait attributions and hypothetical interactions. Results showed evidence for pro-white preference, with younger children and nonwhite children showing higher pro-white bias. Part two of the thesis showed that explicit racial bias was the most consistent predictor of children’s prosocial sharing with recipients of both races as compared to age, gender and contact measures, and was a likely indicator of general prosocial development. Children across ages prioritized self-interest over sharing with others. Part three demonstrated that exposure to positive counterstereotypical black exemplars reduced children’s overall pro-white preferences but had no effect in increasing prosocial behaviour. Results suggest that information-based interventions can be successful at reducing explicit intergroup bias when contact opportunities are limited or insufficient.

Keywords: explicit bias
intergroup bias
outgroup bias
racial bias
resource allocation
Advisor: Lee, Kang