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Guaranteed Conformance of Neurosymbolic Models to Natural Constraints
Get PDFDeep neural networks have emerged as the workhorse for a large section of robotics and control applications, especially as models for dynamical systems. Such data-driven models are in turn used for designing and verifying autonomous systems. This is particularly useful in modeling medical systems where data can be leveraged to individualize treatment. In safety-critical applications, it is important that the data-driven model is conformant to established knowledge from the natural sciences. Such knowledge is often available or can often be distilled into a (possibly black-box) model M. For instance, the unicycle model for an F1 racing car. In this light, we consider the following problem - given a model M and state transition dataset, we wish to best approximate the system model while being bounded distance away from M. We propose a method to guarantee this conformance. Our first step is to distill the dataset into few representative samples called memories, using the idea of a growing neural gas. Next, using these memories we partition the state space into disjoint subsets and compute bounds that should be respected by the neural network, when the input is drawn from a particular subset. This serves as a symbolic wrapper for guaranteed conformance. We argue theoretically that this only leads to bounded increase in approximation error; which can be controlled by increasing the number of memories. We experimentally show that on three case studies (Car Model, Drones, and Artificial Pancreas), our constrained neurosymbolic models conform to specified M models (each encoding various constraints) with order-of-magnitude improvements compared to the augmented Lagrangian and vanilla training methods
Be(Com)ing Who I Am: Social Identity Development in Middle School Students in a Lasallian Independent School
No full textThis dissertation study is designed as qualitative practitioner research that inductively explores middle school students\u27 emic understandings, language, and conceptions of their own identities. The purpose is to understand the nature and range of connections between the social identity development of middle schoolers and contextualized in relation to their Lasallian middle school context and influence. This school-based study seeks to explore how eighth graders make sense of their social identities as they navigate adolescence, middle school, and their multiple worlds utilizing Social Identity Theory as a theoretical framework. Data was collected through individual semi-structured interviews with eleven eighth grade students and a conversation circle with six of the participants. The findings from this research will uplift student voice, emphasize student agency, and identify practices and policies influencing the school culture and climate that support healthy adolescent identity development
Penn Library\u27s LJS 462 - Algorismus ... [etc.]. (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1201/thumbnail.jp
Penn Library\u27s Ms. Codex 1629 - Commentaria ad Rhetoricam (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1104/thumbnail.jp
Penn Library\u27s Ms. Codex 1631 - Ostfriesland history (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1106/thumbnail.jp
It Is Necessary to Make A Complete Breach With the Past : How The Failures of the Second Boer War Shaped British Policy, Politics, and Society in the Edwardian Era
Get PDFThis thesis examines the impact of the Second Boer War on the United Kingdom. Focusing mostly on policy and parliamentary inquiry, the piece explores how British military shortcomings during the war led to a major reorganization of the military and a dramatic expansion of the social safety net. Additionally, the thesis touches upon how the war caused the government to begin more systematically collecting data and led to private-sector efforts to improve the physical condition of the British public
Psychotropic Medication Adherence and Associated Issues in the Adult Forensic Population: A Rapid Scoping Review
No full textABSTRACT
Psychotropic Medication Adherence and Associated Issues in the Adult Forensic Population: A Rapid Scoping Review
Olivia Fojas, LCSW
Dissertation Chair: Phyllis Solomon, Ph.D.
Objective: This rapid scoping review was designed to identify the prevalence, methods of measurement, contributing factors, and interventions related to psychotropic medication adherence with the adult forensic population in institutional and community settings. Methods: Articles were retrieved from PubMed, PsycINFO, Criminal Justice Abstracts with Full Text, and the Dissertation and Thesis Full Text data base. Literature was searched for studies written in English discussing psychotropic medication adherence for adult offenders in institutional or community settings. Title/abstract were reviewed to determine eligibility for inclusion and, if met, the full text article was reviewed. Data were extracted, charted, and analyzed for studies meeting inclusion criteria. Results: Eleven articles met inclusion criteria with varied results. Factors positively associated with adherence included provider empathy, guardian supervision and older age. Factors negatively associated with adherence included younger age and substance abuse. Results were mixed regarding race, gender, therapeutic alliance, and coercion. Structured adherence programs, substance use treatment, medication algorithms and therapeutic modalities like Cognitive Behavioral Therapy and Motivational Interviewing had positive impacts on medication adherence. Conclusion: Variance in adherence definitions and measurements did not allow for meaningful cross comparisons between studies. More research on medication adherence is needed, particularly with offenders with serious mental illness transitioning from jail to the community
Safe Programming Over Distributed Streams
Get PDFThe sheer scale of today\u27s data processing needs has led to a new paradigm of software systems centered around requirements for high-throughput, distributed, low-latency computation.Despite their widespread adoption, existing solutions have yet to provide a programming model with safe semantics -- and they disagree on basic design choices, in particular with their approach to parallelism. As a result, naive programmers are easily led to introduce correctness and performance bugs.
This work proposes a reliable programming model for modern distributed stream processing, founded in a type system for partially ordered data streams. On top of the core type system, we propose language abstractions for working with streams -- mechanisms to build stream operators with (1) type-safe compositionality, (2) deterministic distribution, (3) run-time testing, and (4) static performance bounds. Our thesis is that viewing streams as partially ordered conveniently exposes parallelism without compromising safety or determinism. The ideas contained in this work are implemented in a series of open source software projects, including the Flumina, DiffStream, and Data Transducers libraries
Essays On Private Equity And Healthcare
No full textThis dissertation consists of two chapters that relate private equity and health care. In the first chapter, coauthored with Xuelin Li and Lucian Taylor, we study how common ownership affects innovation. We explore this question using project-level data on pharmaceutical startups and their venture capital (VC) investors. We find that common ownership leads VCs to shut down lagging drug projects, withhold funding from lagging startups, and redirect those startups\u27 innovation. These results support theories dating back to Loury (1979): By coordinating R&D efforts across competing firms, a common owner can reduce duplication of R&D. Consistent with common ownership improving innovation efficiency, common ownership rates are positively correlated with the ratio of R&D output to funding. Though we highlight gains in innovation efficiency, common VC ownership can also impose social costs.
In the second chapter, I use proprietary health insurance claims data covering over 60% of privately insured individuals in the United States to study the impact of private equity (PE) hospital buyouts on hospital-insurer price negotiations, health spending, and patient welfare. I apply a novel structural approach that exploits state-level regulation changes as PE entry shocks. I find that PE buyouts lead to an 11% increase in total healthcare spending for the privately insured in affected markets, driven mostly by higher bargained prices at PE-backed hospitals and price spillovers to local rivals. PE investors\u27 superior bargaining skills account for 43% of the price and spending increases, while financial engineering and bankruptcy threats contribute 40%, changes in patient demand contribute 10%, and reduced focus on social objectives contributes 8%. Operational efficiency gains reduce spending, but only by 1%. A counterfactual ban on PE hospital buyouts would increase patient surplus by an amount equivalent to 10.7% of health expenses. If antitrust regulators who conduct merger reviews ignore PE-backed acquirers\u27 unique features, they risk greatly underestimating the impact of hospital mergers
Transcriptional and Epigenetic Regulation of Endothelial-to-Hematopoietic Transition
No full textHematopoietic stem and progenitor cells (HSPCs) are generated de novo in the embryo from a subset of endothelial cells (ECs) known as hemogenic endothelial cells (HECs). HECs undergo an endothelial-to-hematopoietic transition (EHT) to form HSPCs which requires the transcription factor (TF) RUNX1. RUNX1 is widely regarded as the master regulator of EHT, but RUNX1 alone is insufficient to reprogram adult ECs to HSPCs. Understanding what makes an EC permissive to be specified as hemogenic by RUNX1, as well as the additional TFs that regulate the complex gene regulatory networks controlling HSPC ontogeny is required for efficient and robust generation of HSPCs ex vivo for therapeutic purposes. To uncover novel regulators of HSPC formation, we defined the transcriptomes and enhancer epigenomes of cells representing key developmental stages of HSPC ontogeny. We then constructed developmental-stage-specific transcriptional regulatory networks by linking enhancers to their target promoters and then predicting the bound TFs controlling the enhancer-promoter pair. We predicted known transcriptional regulators of EHT such as RUNX1, validating our overall approach, and identified putative novel TFs, including the ubiquitous TFs SP3 and MAZ. Deletion of either SP3 or MAZ resulted in a reduction in HSPC formation, confirming the role of these TFs in HSPC formation. Cooperation of SP3 and MAZ with RUNX1 was not investigated, but SP3 can directly interact with RUNX1. It is not known what makes an EC competent to be specified as hemogenic by RUNX1. We show that ectopic expression of RUNX1 alone can efficiently promote EHT and HSPC formation from embryonic ECs, but less efficiently from fetal or adult ECs. Efficiency correlated with baseline accessibility of TGFβ-related genes associated with endothelial-to-mesenchymal transition (EndoMT) and participation of AP-1 and SMAD2/3 to initiate further chromatin remodeling along with RUNX1 at these sites. Activation of TGFβ signaling improved the efficiency at which RUNX1 specified fetal ECs as HECs. Thus, the ability of RUNX1 to promote EHT depends on its ability to recruit the TGFβ signaling effectors AP-1 and SMAD2/3, which in turn is determined by the changing chromatin landscape in embryonic versus fetal ECs. This work provides insight into regulation of EndoMT and EHT that will guide reprogramming efforts for clinical applications. The emergence of HSPCs is controlled by the interplay of a multitude of factors including RUNX1, AP-1, SMAD2/3, SP3, and MAZ, all shown here to be critical regulators of HEC specification. This work lays the foundation for understanding the complex transcriptional regulatory network controlling HEC specification and HSPC emergence. Understanding the interplay of these factors, as well as other known regulators of HSPC emergence, will be imperative for generating HSPCs ex vivo for therapeutic purposes