Thesis advisor: Heather T. Rowan-Kenyon / Many postsecondary students in the United States exist at the intersection of multiple marginalized identities, such as race, socioeconomic status, (dis)ability, and legal status. Amidst a tumultuous sociopolitical context, a number of higher education institutions in the United States established Undocumented Student Resource Centers (USRCs), identity-centered student services that provide specialized support for students who hold marginalized legal identities (Ballerini & Feldblum, 2021; Castrellón, 2021; Cisneros & Valdivia, 2018; Cisneros et al., 2021; Gomez & Pérez Huber, 2021; Tapia-Fuselier, 2021). This study, which focuses on the professional employees at USRCs, is ultimately in service of students who are united by their marginalized legal statuses—those who are undocumented, those who are DACA recipients, and those who belong to mixed-status families. This issue is addressed through the following primary research questions: 1) What are the lived experiences of the professional employees who work at USRCs?; 1a) What personal factors inform their experiences in their role?; 2) What are the experiences of USRC professionals when they encounter systemic factors, ranging from the centered to the marginalized? While there is existing literature that recognizes the ways in which USRCs benefit their students, less is known about the experiences of the professional employees who work in USRCs (Cisneros et al., 2021; Tapia-Fuselier, 2021). This hermeneutic phenomenological (van Manen, 1990) study sought to address this gap by examining the experiences of the professional employees of USRCs. Three intersecting frameworks were used to conduct this research: Community Cultural Wealth (Yosso, 2005), Tierney's (1988) framework of Organization, and Critical Systems Thinking (Cordoba & Midgley, 2008; Jackson, 2001; Midgley, 1992; Midgley et al., 1998; Rajagopalan & Midgley, 2015; Raza, 2021; Ulrich, 1983, 1988). The sample consisted of 6 professional employees from 2- and 4-year higher education institutions across the United States. Three semi-structured interviews were conducted with each participant, and data was analyzed using the hermeneutic circle (Dibley et al., 2020; van Manen, 1990). The findings indicate that the professional employees of USRCs bring untold assets and forms of wealth to their work, including their commitment to joy and their employment of aspirational, familial, and navigational capital. Systemic factors within their organization and beyond create barriers to their work, resulting in mentally and emotionally exhausting experiences, overburdened work environments, and instances where their identities and offices are marginalized by their tumultuous sociopolitical context. Implications for higher education practice, research, and theory are offered. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

Modern complex safety-critical socio-technical systems (STSs) operate in an environment that requires high levels of human-machine interaction. Given the potential for catastrophic events , understanding human errors is a critical research area spanning disciplines such as management science, cognitive engineering, resilience engineering, and systems theory. However, a research gap remains when researching how errors impact system performance from a systemic perspective. This dissertation employs a systematic methodology and develops models that explore the relationship between errors and system performance, considering both macro-organizational and micro-worker perspectives. In Essay 1, the focus is on how firms respond to serious errors (catastrophic events), by exploring the oscillation behavior associated with the organizational learning and forgetting theory. The proposed simulation model contributes to the organizational science literature with a comprehensive approach that assesses the firm's response time to "serious" errors when the firm has a focus on safety with established safety thresholds. All of these considerations have subsequent impact on future performance. Essay 2 explores the relationship between safety-critical system's workers' workload, human error, and automation reliance for the Belgian railway traffic control center. Key findings include a positive relationship between traffic controller performance and workload, and an inverted U-shaped relationship with automation usage. This research offers new insights into the effects of cognitive workload and automation reliance in safety-critical STSs. Essay 3 introduces a calibrated System Dynamics model, informed by empirical data and existing theories on workload suboptimality. This essay contributes to the managerial understanding of workload management, particularly the feedback mechanism between operators' workload and human errors, which is driven by overload and underload thresholds. The model serves as a practical tool for managerial practitioners to estimate the likelihood of human errors based on workload distributions. Overall, this dissertation presents an interdisciplinary and pragmatic approach, blending theoretical and empirical methodologies. Its broad impacts extend across management science, cognitive engineering, and resilience engineering, contributing significantly to the understanding and management of safety-critical socio-technical systems. / Doctor of Philosophy / This dissertation is motivated by the increasing autonomy in infrastructure systems designed to enhance safety performance. Yet paradoxically, we continue to witness system failures leading to catastrophic disasters. High-profile incidents such as the Metro-North train derailment in New York City, the Boeing 737 MAX plane crashes, and the Challenger and Columbia space shuttle accidents highlight this contradiction. This research delves into safety-critical systems where the intricate collaboration between humans and machines is crucial, and where even minor human errors can lead to disastrous consequences. This dissertation is presented in three parts. In the first part I examine how firms react to serious errors. The study focuses on their learning processes following safety incidents and the potential for these lessons to be forgotten over time. I introduced a simulation model grounded in the organizational science literature, offering deeper insights into how companies respond to errors, including changes in safety focus, safety culture, and policy, and the impact of these factors on future company's performance. The second part shifts to a worker-centered perspective, exploring the relationship between workload, performance, and automation usage among traffic controllers. The findings indicate that while performance can improve with an increase in workload up to a certain threshold, excessive reliance on automation may lead to a decline in performance. This part of the study sheds light on how cognitive workload and technology usage influence operators in safety-critical roles. The final part of the dissertation presents another simulation model, this time focusing on how workload, and the resulting stress and boredom due to workload, influence the likelihood of errors. Utilizing real operational data from the Belgian railway transportation system, this model aids managers in understanding how to optimally balance workloads to minimize error risks. Overall, this dissertation takes an interdisciplinary and pragmatic approach, merging theoretical concepts with empirical data. Its extensive impact spans management science, cognitive engineering, and resilience engineering, significantly enhancing our comprehension and management of safety-critical socio-technical systems.

Agricultural technology development has historically exacerbated social inequities. As agriculture progresses into the latest technological revolution – Ag 4.0 – it is unclear how institutions such as land-grant universities are considering the social implications of their agricultural technology research. The purpose of this study is to explore how land-grant university initiatives focusing on agricultural technology consider the implications of agricultural technology research. To do so, this research focuses on Virginia Tech's Center for Agricultural Innovation in Agriculture (CAIA). Guided by critical systems heuristics, this case study utilizes five data collection methods to inform a critical case study including: key informant interviews, a document review, a survey, stakeholder interviews, and a focus group. While striving to be a cross-campus interdisciplinary and innovative research incubator the findings revealed in the five years since its establishment, CAIA has been shaped by structural norms at Virginia Tech's College of Agriculture and Life Sciences (CALS), reducing its interdisciplinary and innovation potential. Rather, CAIA supports the existing research of CALS faculty. CAIA has adopted measures of success that ideologically aligned with techno-solutionism and, while present, consideration for the social impact of agricultural technology research is a secondary priority. While this is consistent with ongoing trends in a neoliberalized higher education system, CAIA can take deliberate steps to uplift social impact in agricultural technology research such as being deliberate with who is engaged in the center towards interdisciplinary research, and working with CALS to ensure public-private partnerships serve the direct needs of small and medium-sized growers in Virginia. Empirically, this study contributes to the ongoing discourse around the neoliberalized land-grant university and the use of critical systems heuristics to guide research involving agricultural innovation systems. / Doctor of Philosophy / Agricultural technology has often increased social inequalities. As agriculture moves into a new technological era, called "Ag 4.0," it is unclear how our land-grant universities like Virginia Tech, are thinking about the social impacts of their research on agricultural technology. This case study, using a theory called critical systems heuristics, focuses on Virginia Tech's Center for Agricultural Innovation in Agriculture (CAIA) to understand the social implications of the technologies they develop. Social implications include the effects technology may have on one's ability to farm according to cultural practice or ability to afford the technology. Using five methods — key informant interviews, document reviews, surveys, stakeholder interviews, and a focus group — the study shows that CAIA sought to encourage innovative research across different academic disciplines. However, in practice, CAIA functions as a way to support existing projects of Virginia Tech's College of Agriculture and Life Sciences (CALS) faculty. Although CAIA's affiliated faculty stive to consider the social impact of its work, its main focus is developing agricultural technology that is broadly useful to the agricultural industry. This reflects trends in today's higher education system, where universities are increasingly mindful of their economic and political context. However, CAIA could take steps to increase its focus on social impacts by involving a wider range of voices in research and ensuring that its partnerships with private businesses directly support small and medium-sized farms in Virginia. This study adds to the conversation about how universities can play a role in promoting socially responsible technology in agriculture.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Safety critical systems are systems where its failures can cause irreparable damage for this reason the development of safety critical systems involves safety issues and require rigorous validation in the certification process. Certification processes are expensive and lengthy to follow laws and rigorous rules. With the continuous evolution provided by general purpose programming languages, ease of learning, and the use of these languages in industry and academy, researches have been performed aiming to adapt general purpose programming languages for use in safety-critical applications. The purpose of these adaptations is to reduce the scope of commands found in general purpose languages in order to develop safety critical systems, for example, to avoid or reduce the use of recursions. Some examples of these adaptations include the Real Time Specification for Java (RTSJ), developed in 1998 and Safety Critical Java. SCJ uses objects and concepts defined by the RTSJ focusing on the development of safetycritical applications. In SCJ, the concept of missions is deployed where each mission consists of schedulable objects defined by the RTSJ. The portability of a Java application is one of the main factors for choosing this language. However, there is great difficulty in finding virtual machines for embedded safety-critical systems, therefore it is difficult to benefit from the portability provided by the Java virtual machine in this context. Nevertheless, an application developed in the C++ programming language can be executed directly on the device without using a virtual machine. This work presents a translation of the Safety Critical Java to the C++ programming language, maintaining the behaviour of objects that implement the concept of missions for SCJ in C++. This enables the execution of safety-critical applications in embedded devices without the use of a virtual machine. / Sistemas críticos são sistemas em que suas falhas podem causar danos irreparáveis como colocar a vida de pessoas em risco e por este motivo envolve questões de segurança e exige uma validação rigorosa no processo de certificação. Processos de certificação são caros e demorados que seguem leis e regras rigorosas. Com a evolução contínua proporcionada por linguagens de programação de propósito geral, a facilidade de aprendizado, assim como a utilização destas linguagens na indústria e acadêmia, pesquisas vem sendo realizadas com o intuito de adaptar linguagens de programação de propósito gerais para serem utilizadas em aplicações críticas de tempo real. O objetivo destas adaptações é de tornar o escopo de comandos das linguagens para desenvolvimento de sistemas críticos mais restritos, como por exemplo, ao evitar ou reduzir a utilização de recursões. Alguns exemplos dessas adaptações são a Especificação de Tempo Real Java (Real Time Specification for Java - RTSJ) desenvolvida no ano de 1998, e a Safety Critical Java (SCJ) que utiliza objetos e conceitos definidos pela RTSJ com enfoque no desenvolvimento de aplicações para sistemas críticos. Na SCJ foi implementado o conceito de missões onde cada missão é composto por objetos escalonáveis definidos pela RTSJ. A portabilidade de uma aplicação desenvolvida em Java é um dos principais fatores dos quais desenvolvedores desejam utilizá-la. Todavia, existe uma grande dificuldade de encontrar máquinas virtuais para sistemas críticos embarcados, dificultando a portabilidade da qual a linguagem Java fornece. Por outro lado, uma aplicação desenvolvida na linguagem de programação C++ pode ser executada diretamente no dispositivo sem a necessidade de utilizar uma máquina virtual. Por este motivo, nesta dissertação é apresentada uma tradução da especificação Safety Critical Java na linguagem de programação C++, com o objetivo de manter o comportamentos de uma aplicação desenvolvida em SCJ e assim possibilitando a execução de uma aplicação com requisitos temporais em diversos dispositivos embarcados.

Este trabalho propõe o uso de Sistemas de Informação e Inteligência Empresarial visando a Análise Inteligente de Falhas para Apoiar Decisões Estratégicas em Projetos de Sistemas Críticos. Tal proposta estabelece uma correlação entre a dinâmica proveniente de recursos e ferramentas de Sistemas de Informação e Inteligência Empresarial, e a necessidade de se obter informações precisas, em intervalos de tempo aceitáveis para agregar valores tangíveis na segurança, confiabilidade, disponibilidade e mantenabilidade de Sistemas Críticos. A proposta aqui apresentada vem ao encontro da necessidade premente de disponibilizar, com maior eficácia, informações precisas para a aferição de indicadores importantes ao Projeto de Sistemas Críticos, e favorecer a implementação de ações mitigadoras de falhas que possam vir a comprometer o funcionamento desses sistemas. De forma a completar e consolidar a proposta em questão desenvolveu-se um ambiente computacional, utilizando-se dos fundamentos teóricos e das melhores práticas de Sistemas de Informação e Inteligência Empresarial, com as especificidades inerentes a Sistemas Críticos. Avaliou-se tal ambiente em um estudo de caso desenvolvido no Sistema Metroviário de São Paulo. Esse estudo de caso contribuiu, no aspecto conceitual, com a realização de ensaios de análises qualitativas e quantitativas de falhas, fornecendo informações relevantes para apoiar possíveis decisões estratégicas no sistema estudado. / This work proposes the use of Information Systems and Business Intelligence aiming an Intelligent Analysis of Failure that supports Strategic Decision Making in Critical Systems Projects. This proposition establishes a correlation between the dynamics of resources and tools from Information Systems and Business Intelligence, and the need to obtain accurate information within an acceptable time interval to add tangible value in security, reliability, availability and maintainability of Critical Systems. The proposition presented here meets the need to provide, more efficiently, accurate information to measure relevant indicators of the projects in Critical Systems, and favor the implementation of failure mitigating actions that could come to compromise the functioning of these systems. In order to complete and consolidate the proposition in question, a computational environment was developed, making use of the theoretical bases and of the best practices of Systems of Information and Business Intelligence, with the peculiarities inherent to Critical Systems. Such environment was evaluated in a case study in the Metrorail Company of São Paulo State, in which qualitative and quantitative analysis of failures were tested, providing relevant information to support possible strategic decisions in the system studied.

This thesis focusses on the properties of, and relationships between, several fundamental objects arising from critical physical models. In particular, we consider Schramm--Loewner evolutions, the Gaussian free field, Liouville quantum gravity and the Brownian continuum random tree. We begin by considering branching diffusions in a bounded domain $D\subset$ $R^{d}$, in which particles are killed upon hitting the boundary $\partial D$. It is known that such a system displays a phase transition in the branching rate: if it exceeds a critical value, the population will no longer become extinct almost surely. We prove that at criticality, under mild assumptions on the branching mechanism and diffusion, the genealogical tree associated with the process will converge to the Brownian CRT. Next, we move on to study Gaussian multiplicative chaos. This is the rigorous framework that allows one to make sense of random measures built from rough Gaussian fields, and again there is a parameter associated with the model in which a phase transition occurs. We prove a uniqueness and convergence result for approximations to these measures at criticality. From this point onwards we restrict our attention to two-dimensional models. First, we give an alternative, ``non-Gaussian" construction of Liouville quantum gravity (a special case of Gaussian multiplicative chaos associated with the 2-dimensional Gaussian free field), that is motivated by the theory of multiplicative cascades. We prove that the Liouville (GMC) measures associated with the Gaussian free field can be approximated using certain sequences of ``local sets" of the field. This is a particularly natural construction as it is both local and conformally invariant. It includes the case of nested CLE$_{4}$, when it is coupled with the GFF as its set of ``level lines". Finally, we consider this level line coupling more closely, now when it is between SLE$_{4}$ and the GFF. We prove that level lines can be defined for the GFF with a wide range of boundary conditions, and are given by SLE$_{4}$-type curves. As a consequence, we extend the definition of SLE$_{4}(\rho)$ to the case of a continuum of force points.

O desenvolvimento de sistemas críticos é atualmente um dos problemas mais desafiadores enfrentados pela Engenharia. Há frequentemente uma pressão para se reduzir o tempo total de desenvolvimento, o que dificulta a entrega de sistemas com um mínimo aceitável de defeitos. Nos últimos anos, houve um aumento no tráfego aéreo, o que demanda uma modernização dos sistemas de tráfego aéreo atuais, muito dependentes na figura do controlador. Sistemas de tráfego aéreo são sistemas considerados críticos em segurança e de tempo real. O objetivo do presente trabalho é estabelecer um método de modelagem e verificação formal para sistemas críticos, com aplicação no domínio de tráfego aéreo. Com a adoção de técnicas de modelagem e verificação formal, pretende-se garantir a corretude dos sistemas frente aos requisitos inicialmente especificados e a detecção de erros em fases mais iniciais do projeto, o que resultaria em menores custos envolvidos na sua correção. São fornecidas diretivas para a aplicação do método através de um estudo de caso, baseado em três módulos de um sistema ATC em baixo nível de abstração, para a validação do funcionamento de módulos de software. Para verificação formal, é utilizada a ferramenta NuSMV e as propriedades a serem verificadas são descritas na lógica computacional de árvore (CTL) para garantir que o sistema satisfaça requisitos dos tipos vivacidade e segurança. / Developing safety critical systems is one of the most challenging problems in Engineering nowadays. There is usually a pressure to reduce the total time of the development, what makes it difficult to deliver systems with an acceptable low level of defects. In the recent years, there has been an increase in air trffic, what demands a modernization in the current air traffic systems, which are very dependent on the human controller. Air traffic systems are considered safety critical and real time systems. The objective of the present work is to establish a modeling and formal verification method for critical systems, applicable to the air traffic domain. By adopting modeling and formal verification techniques, it is expected to ensure the systems\' correctness compared with the initially specified requirements and the error detection in the initial phases of the project. Guidelines are provided for applying the method by means of a case study, based in three modules of and ATC system in a low abstraction level, for the validation of the operation of software modules. For the formal verification, it is used the NuSMV tool and the properties to be checked are described in the computational tree logic (CTL) to ensure that the system satisfies requirements of liveness and safety types.