Provable Guarantees for Generative Behavior Cloning: Bridging Low-Level Stability and High-Level Behavior

We propose a theoretical framework for studying behavior cloning of complex expert demonstrations using generative modeling. Our framework invokes low-level controllers - either learned or implicit in position-command control - to stabilize imitation around expert demonstrations. We show that with (a) a suitable low-level stability guarantee and (b) a powerful enough generative model as our imitation learner, pure supervised behavior cloning can generate trajectories matching the per-time step distribution of essentially arbitrary expert trajectories in an optimal transport cost. Our analysis relies on a stochastic continuity property of the learned policy we call "total variation continuity" (TVC). We then show that TVC can be ensured with minimal degradation of accuracy by combining a popular data-augmentation regimen with a novel algorithmic trick: adding augmentation noise at execution time. We instantiate our guarantees for policies parameterized by diffusion models and prove that if the learner accurately estimates the score of the (noise-augmented) expert policy, then the distribution of imitator trajectories is close to the demonstrator distribution in a natural optimal transport distance. Our analysis constructs intricate couplings between noise-augmented trajectories, a technique that may be of independent interest. We conclude by empirically validating our algorithmic recommendations, and discussing implications for future research directions for better behavior cloning with generative modeling.Comment: updated figures, minor notational change for readabilit

Mathematical Models and Decomposition Algorithms for Cutting and Packing Problems

In this thesis, we provide (or review) new and effective algorithms based on Mixed-Integer Linear Programming (MILP) models and/or decomposition approaches to solve exactly various cutting and packing problems. The first three contributions deal with the classical bin packing and cutting stock problems. First, we propose a survey on the problems, in which we review more than 150 references, implement and computationally test the most common methods used to solve the problems (including branch-and-price, constraint programming (CP) and MILP), and we successfully propose new instances that are difficult to solve in practice. Then, we introduce the BPPLIB, a collection of codes, benchmarks, and links for the two problems. Finally, we study in details the main MILP formulations that have been proposed for the problems, we provide a clear picture of the dominance and equivalence relations that exist among them, and we introduce reflect, a new pseudo-polynomial formulation that achieves state of the art results for both problems and some variants. The following three contributions deal with two-dimensional packing problems. First, we propose a method using Logic based Benders’ decomposition for the orthogonal stock cutting problem and some extensions. We solve the master problem through an MILP model while CP is used to solve the slave problem. Computational experiments on classical benchmarks from the literature show the effectiveness of the proposed approach. Then, we introduce TwoBinGame, a visual application we developed for students to interactively solve two-dimensional packing problems, and analyze the results obtained by 200 students. Finally, we study a complex optimization problem that originates from the packaging industry, which combines cutting and scheduling decisions. For its solution, we propose mathematical models and heuristic algorithms that involve a non-trivial decomposition method. In the last contribution, we study and strengthen various MILP and CP approaches for three project scheduling problems

Women’s Friendship in Medieval Literature

In Women’s Friendship in Medieval Literature, Karma Lochrie and Usha Vishnuvajjala bring together established scholars and new voices to illuminate a previously understudied but consequential element of life in the Middle Ages. Contributors focus on representations of women’s friendships in medieval European literature and their afterlives both to historicize them and draw out the finer nuances of the multitude of forms, affects, values, and ethics that emerge within those friendships. This volume examines works by Chaucer, Gower, Malory, Marie de France, female saints, and late–Middle Scots poets alongside lesser-known late medieval lyrics and Middle English romances to chart women’s friendships and their many and sometimes conflicting affinities with the cultural categories of gender, religion, politics, and sexuality. In addition to exploring the parameters of female friendship across a range of texts and historical contexts, contributors evaluate the political, religious, and civic structures negotiated in public and private and engage with the long history of theory and philosophy on friendship. The result is a theoretical and historical rubric for the future study of women’s friendships in medieval texts and beyond

Women’s Friendship in Medieval Literature

In Women’s Friendship in Medieval Literature, Karma Lochrie and Usha Vishnuvajjala bring together established scholars and new voices to illuminate a previously understudied but consequential element of life in the Middle Ages. Contributors focus on representations of women’s friendships in medieval European literature and their afterlives both to historicize them and draw out the finer nuances of the multitude of forms, affects, values, and ethics that emerge within those friendships. This volume examines works by Chaucer, Gower, Malory, Marie de France, female saints, and late–Middle Scots poets alongside lesser-known late medieval lyrics and Middle English romances to chart women’s friendships and their many and sometimes conflicting affinities with the cultural categories of gender, religion, politics, and sexuality. In addition to exploring the parameters of female friendship across a range of texts and historical contexts, contributors evaluate the political, religious, and civic structures negotiated in public and private and engage with the long history of theory and philosophy on friendship. The result is a theoretical and historical rubric for the future study of women’s friendships in medieval texts and beyond

Silenced voices/speaking bodies : female performance and cultural agency in the court of Anne of Denmark (1603-19)

This study investigates the long-neglected cultural engagement of the court of Anne of Denmark, consort of James VI and I, revising her historiographical representation in the light of current gender theory. Focusing upon the masque performances of the English Jacobean court, I examine the genre's anomalous staging of Renaissance female performance and its contribution to the emergence of a more general female performance. Through detailed analysis of masque performances, I assess contemporary courtly attitudes towards female masquing and the performative representation of the courtly woman. This study is firmly interdisciplinary in its approach to female cultural production, investigating the texts of performance, embroidery, dance, patronage and commissioning, and religious and political engagement. This thesis breaks new ground in the detailed examination of the aesthetics of masque performance as tools of social and political engagement. This study decentres the anglocentricism prevalent in recent cultural criticism of the Jacobean court. My first: chapter traces Anne's life and performance in both the Danish and Scottish Renaissance courts, assessing the impact of these alternative models upon her cultural engagement. Chapters two and three continue the analysis of performance. The former discusses the danced performance of aristocratic identity and the way in which this facilitates female masque performance; the latter relates the performance of the female body in the major English Jacobean masques to performance space, costume and scenery. Tracing the line of female performance through the second decade of the seventeenth century, I analyse Robert White's Cupid's Banishment, the final masque of Anne's career. This reading encapsulates my discussion of female cultural agency through the autonomy of the Queen's court. Recycling memories of earlier performances, Cupid's Banishment stages disparate texts of female expressivity in a masque which contains perhaps the unique Jacobean staging of the female masquing voice

Purgative Texts: Religion, Revulsion, and the Rhetoric of Insurgency in Early Modern England

In this dissertation I explore the ways that writers of early modern religious and social polemic used humoral language in order that their texts were not only rhetorically powerful, but also served as efficacious humoral remedies in the form of "physic" or medicinal "cures." Specifically, I consider several examples of religio-political tracts that label themselves as "purgatives." Each of the treatises I examine claims to diagnosis and treat either the diseased individual and/or the distempered body politic. Both Stephen Gosson (School of Abuse 1579) and Martin Marprelate (Marprelate tracts 1588-9) label themselves as physicians or sugeons. Gosson offers his tract as curative medicine for an effeminate, phlegmatic body politic. Marprelate himself is a "mirror" of the deformity in the body politic and his text/body a "cure." The three defenses of womenJane Anger's Her Protection for Women (1589), Esther Sowernam's Esther hath Hanged Haman (1617), and Constantia Munda's Worming of a madde dogg (1617)represent written words as purges for the male writers they are answering. And, finally, The Lady's words have a potentially transformative effect on Comus in Milton's A Masque. Central to this project is the notion that words have humoral valences as do all substances that "issue" from the body. Through speech and writing people conveyed the very substance of their souls according to early modern physicians and religious leaders, whose treatise addresses the connection between the state of a person's body, soul, and words. Words, like the people who spoke them, could be "hot," bilious, choleric. The solution offered by the purgative text is the power to flush the body of corruption. Because textual arguments can carry humoral valences, they are not merely rhetorically persuasive, but potentially transformative on every level. Analyzing the humoral language in early modern polemic changes the way we are compelled to read similar language in other literary and non-literary texts, deepening our understanding of what it means to "change" a person's mind

Strange and Terrible Wonders: Climate Change in the Early Modern World

The study of climate and climatic change began during the Little Ice Age of the early modern world. Beginning in the sixteenth century, European clerics, scientists, and natural philosophers penned detailed observations of the era’s unusually cool and stormy weather. Scouring the historical record for evidence of similar phenomena in the past, early modern scholars concluded that the climate could change. By the eighteenth century, natural philosophers had identified at least five theories of climatic change, and many had adopted some variation of an anthropogenic explanation. The early modern observations described in this dissertation support the conclusion that cool temperatures and violent storms defined the Little Ice Age. This dissertation also demonstrates that modern notions of climate change are based upon 400 years of rich scholarship and spirited debate. This dissertation opens with a discussion of the origins of “climate” and meteorology in ancient Greek and Roman literature, particularly Aristotle’s Meteorologica. Although ancient scholars explored notions of environmental change, climate change—defined as such—was thought impossible. The translation and publication of ancient texts during the Renaissance contributed to the reexamination of nature and natural variability. In the sixteenth century, most scholars interpreted weather phenomena through the lenses of theology, astrology, and meteorology. None of these provided a model for great winters or long-term climatic change. The first great storms of the Little Ice Age encouraged observant scholars to construct meteorological chronicles to facilitate the comparison of ancient and modern weather events. The first references to climatic change date to this era, though most observers concluded that contemporary phenomena were no worse than their predecessors. The Scientific Revolution transformed the practice of meteorology in seventeenth-century Europe. Professional scientific organizations encouraged careful observation, standardized reporting, and collaborative research. Late seventeenth-century scientists proposed the first natural, rather than theological, theories of climatic change, while eighteenth century geologists and historians worked to incorporate new weather records into their conclusions. By the early nineteenth century, most scholars acknowledged some degree of climatic change, and many concluded that human civilization bore some responsibility