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The Long Duration Space Mission Operations Cost Estimator Model (LDurSMOCE)
Get PDFRobotic space flight has allowed us to explore the sun, planets and moons of our solar system, well beyond the current limitations of human space flight. In addition, technologies such as nuclear power have allowed spacecraft to be powered for longer periods of time, without substantial increase in mass, increasing our ability to explore. With the increased capability to operate missions over multiple decades, this has enabled more distant exploration. In order to continue successful implementation of these missions, careful planning and management is required. An essential part of mission success is the ability to control cost growth. Much research has been published about cost growth during mission development, but the same attention has not been given to mission operations. This does not mean cost growth during operations does not exist, simply the majority of planned primary mission lifetimes have been less than a decade long; therefore, the overall cost of mission operations is substantially lower than development. As a result, research in the cost growth of mission operations has not been prioritized.
This dissertation builds upon the current knowledge base of what we know about mission operations costs to provide projects with a tool in which to plan and make decisions regarding longer duration operations. This tool is presented in the form of a parametric cost model that incorporates longevity components that are not typically seen on shorter missions. LDurSMOCE, Long Duration Space Mission Operations Cost Estimator, contains 5 sizing parameters and 9 cost drivers. LDurSMOCE adopts the NASA standard work breakdown structure (WBS) as described in NPR 7120.5F to allocate cost and define its scope.
The model is focused on long duration NASA missions, with the underlying data set coming primarily from The Planetary Society’s Budget Dataset and internal APL cost reporting on NASA funded projects. Ultimately, the contributions of this dissertation can be summarized as the following: (1) advancing our understanding of what it takes programmatically and cost-wise to stand up a long duration space mission, and (2) advancing the state of the practice in estimating the effort it takes to conduct mission operations for multiple decades
RELATIVE PERFORMANCE OF TWO FORMS OF FISHER INFORMATION IN STATISTICAL INFERENCE
Get PDFMaximum likelihood estimation (MLE) is a well-known technique used to make statistical predictions. In practical terms, figuring out how accurate these predictions are is crucial. This involves constructing the confidence region for the MLE, which is a way to measure how much we can trust the estimate. Standard statistical theory shows that the normalized MLE is asymptotically normally distributed with the covariance matrix being the inverse of the Fisher information matrix (FIM) at the unknown parameter. There are two main approximations: the inverse of the observed FIM (which is the same as the inverse Hessian of the negative log-likelihood) or the inverse of the expected FIM (the same as the inverse FIM). Both approximations rely on evaluations made at the MLE based
on the sample data.
In this thesis, we show that under reasonable conditions, similar to those typically applied to MLE, the expected FIM provides a better approximation for the MLE model’s confidence region than the observed FIM. Specifically, in an asymptotic context, the eigenvalues and eigenvectors of the expected FIM, when evaluated at the MLE, manifest a lower mean squared error relative to the true
covariance matrix than those derived from the observed FIM. This conclusion is supported by theoretical explanations and numerical experiments across two distinct problems
ADDRESSING CONFOUNDING IN EVALUATIONS OF PUBLIC HEALTH POLICIES WITH STAGGERED IMPLEMENTATION: A COMPARISON OF STATISTICAL METHODS
Get PDFThis thesis critically evaluates the effectiveness of various statistical models for correcting bias imposed by observed confounders in estimating the average treatment effect on the treated (ATT) of staggered policy implementations, using real-world opioid policy-motivated data scenarios. The staggered Difference-in-Differences (DID) methodology is explored due to its frequent application in policy intervention analyses. This approach extends the traditional two-group/two-period setting to more complex settings involving variations in treatment timing across groups and multiple measurement time points, utilizing control group outcome trends as proxies for unobserved outcomes in treated groups.
The research employs a simulation framework, influenced by the seminal work of Zeldow and Hatfield (2021), which compared statistical methods for correcting bias due to observed confounders in DID analyses with a single implementation time. Several estimators are considered, including the standard two-way fixed effects models, methods developed by Callaway and Sant’Anna (2021), Sun and Abraham (2021), and Roth and Sant’Anna (2023), as well as autoregressive models and augmented synthetic control methods. These methods are evaluated for their ability to handle observed confounding variables and provide accurate estimates of average policy effects.
The findings indicate that model selection significantly affects the accuracy and precision of estimates, underscoring the importance of choosing appropriate analytical tools that align with the specific features of the data and study design. Models that incorporate adjustments for time-varying effects of covariates demonstrate potential in mitigating bias introduced by confounders.
This study contributes to the literature by offering insights into the selection and application of DID models in policy evaluation, particularly in settings with staggered policy implementations. The results emphasize the need for rigorous examination of model assumptions and suggest avenues for future research, including the development of robustness checks for assumption violations in DID analyses, thereby improving the efficacy of policy impact evaluations
COMPARATIVE ANALYSIS OF GREEN AND PINK HYDROGEN PRODUCTION IN JAPAN BASED ON A PARTIAL CIRCULAR ECONOMY APPROACH
Get PDFGiven Japan's energy and environmental situations, this research study seeks to explore the best reasonable, practical, and economic future (2040-beyond) source of clean hydrogen (green or pink) for Japan if produced based on a partial circular economy approach. The paper explains the capstone's background and rationale, Japanese energy and environmental security, resilience and reliability situations, types of hydrogen production, and the current state of clean hydrogen development in Japan. The analysis in this research paper builds upon the inspiration of the Japanese mottainai movement and three theoretical frameworks governing the selection of data and criteria for comparative analysis of green and pink hydrogen production in Japan based on a partial circular economy approach. First, the study uses the technical cycle of the Ellen MacArthur Foundation's (2024) circular economy system diagram for structuring comparative analysis. The author's previously developed qualitative concepts, such as the quasi-revolutionary transition for developing US coastal green H2 hubs and nexus-integrated policies for Japan, also inform the paper's methodology. The study also addresses limitations and provides future research directions
Federal Energy Resilience: Valuation, Financing, and Contracting Strategies
Get PDFClimate change presents growing threats to U.S. federal real property, particularly in energy and water systems, which face surging risks from frequent and severe climate-driven hazards. While significant public sector investments made possible by the shifting energy market and legislation such as the Infrastructure Investment and Jobs Act and the Inflation Reduction Act, have targeted climate mitigation, the disparity in funding for adaptation and resilience strategies leaves federal assets vulnerable. This capstone evaluates the potential of performance contracting as a financial mechanism for addressing resilience gaps in federal infrastructure without burdening federal agencies with reliance on cumbersome appropriations processes. By leveraging case studies, legislative analysis, and private sector resilience valuation methodologies, the research explores innovative contracting solutions to integrate energy and water resilience measures into federal projects. The findings underscore the necessity of legislative updates to enable resilience-focused performance contracts, with an emphasis on quantifying the economic value of avoided outages and downtime costs. The study proposes policy recommendations to expand contracting authority, establish resilience grants, and create frameworks for integrating resilience metrics into federal budgeting and procurement processes. Ultimately, this work aims to support federal agencies in deploying scalable and sustainable resilience strategies critical to mission assurance and infrastructure security
RUNNING WILD DEFYING BINARIES AND BOUNDARIES
No full textI am drawn to living beings that are displaced and marginalized, that defy classification and categorization, and that not only survive but thrive outside of binaries and boundaries. I count myself among their number. Here are a few of our stories
STORIES AT THE CROSSROADS: NARRATIVES AT THE INTERSECTION OF THE NATURAL AND HUMAN-BUILT ENVIRONMENT
No full textNaturally occurring and human-built environments have intermingled for centuries. This portfolio is a collection of stories, narratives, and news articles from the spaces where the two meet. Some of these stories are peaceful, featuring a cooperative relationship between the two worlds. Others are more violent. Sometimes, the conflict is wholly within one world, e.g., nature vs. nature. These stories are snapshots of the many different kinds of relationships that exist between the two worlds
Building Resilience: A White Paper on Enhancing Disaster Risk and Vulnerability Assessments in Developing Countries
Get PDFClimate change is intensifying the frequency and severity of global disasters, disproportionately impacting developing countries due to their geographical vulnerabilities, resource constraints, and institutional challenges. This paper critically examines the implementation and effectiveness of National Disaster Risk Assessments (NDRAs) in these contexts, drawing on empirical evidence from a diverse range of case studies, including Nepal, Rwanda, Bangladesh, Mozambique, and others, alongside insights with OECD countries. The findings reveal systemic gaps in data availability, institutional coordination, and the practical application of international guidelines, such as the UNDRR's 2017 “Words into Action Guidelines: National Disaster Risk Assessment for NDRAs.
Quantitative approaches, while valuable for detailed analysis, are often constrained by resource demands and technical complexities, limiting their feasibility in resource-constrained settings. Conversely, qualitative and participatory methods emerge as pragmatic alternatives, providing actionable insights while incorporating local knowledge and community-level engagement. Comparative risk analysis, employed successfully in OECD contexts, demonstrates potential for prioritizing risks and aligning national policies in developing nations when adapted to local capacities.
This study proposes a tailored framework emphasizing simplification, inclusivity, and contextual adaptability, bridging the gap between theoretical guidelines and on-the-ground realities. By fostering national ownership, aligning NDRAs with socio-economic and political contexts, and integrating local perspectives, NDRAs can serve as catalysts for mainstreaming disaster risk reduction into sustainable development strategies. This paper contributes to a nuanced understanding of DRM in developing countries, offering actionable recommendations to enhance resilience against climate-induced disasters
CALIFORNIA’S DEEP RELATIONSHIP TO WATER: EMPOWERING LOCAL COMMUNITIES AND NATURE-BASED SOLUTIONS
Get PDFThe San Joaquin Delta in Northern California (CA) provides much of the state with water for its agricultural industry and urban regions. Over the years, this rich biodiverse and culturally rich region has been exploited by western thought processes of for-profit economics and development, often at the expense of Delta residents physical and emotional well-being. Many studies have been done to push environmental or economic water policy but never ask what
residents’ relationship to the water is. Several Delta residents were interviewed and asked about their emotional relationship to Delta waterways and CA state agencies. Interviewed residents demonstrated a close-knit relationship, kinship, to the water on economic, cultural, and emotional levels. Kinship embraces mutual respect, understanding that Delta waterways grant life and take it away. This is ignored by policymakers when implementing state policy to advance outside interests; therefore, decolonizing policy to reflect residents’ needs is crucial. Shifting power from CA state agencies to local government can empower residents to have a greater say in water policy and embrace a holistic approach that covers nature-based solutions, mutual respect, and Indigenous stewardship. Doing so will help the San Joaquin Delta communities, watershed, and CA state government interests flourish and adapt to climate change in the 21st centur
Oral History Interview with Jonathan Moreno
No full textThis interview was conducted in person with Jonathan Moreno, PhD, as part of “Moral Histories: Voices and Stories from the Founding Figures of Bioethics,” an oral history project of the Johns Hopkins University Berman Institute of Bioethics. Professor Moreno is the David and Lyn Silfen University Professor Emeritus of Medical Ethics and Health Policy, Philosophy, and History and Sociology of Science at the University of Pennsylvania. He is the author of over twenty-four books and hundreds of articles. His areas of expertise include neuroethics, biotechnology, and national security, with a particular interest in the history and sociology of bioethics.
In this interview Moreno discusses his childhood and the intellectual influence of his parents, particularly his father J.L. Moreno, who was renowned for developing the therapeutic model of psychodrama and the idea of social networks. He discusses his philosophy graduate studies and shares how he became involved in bioethics as one of the first “staff philosophers” in hospitals early in his career. He discusses his gradual move towards government and policy ethics, including being on the staff of Advisory Committee on Human Radiation Experiments (ACHRE) during the Clinton Administration; the Advisory Committee on Human Embryonic Stem Cell Research for the National Academy of Sciences; Department of Defense consulting; creating “Science Progress” content as a senior fellow at the Center for American Progress; and being on the Obama presidency transition team. Post-9/11 issues of biosafety and bioterrorism are discussed, as well as his experience consulting on the ethics related to force-feeding, interrogation, and the different approaches of the CIA and Army regarding Guantanamo prisoners post 9/11.
Moreno reflects on being a senior advisor for the Obama administration’s Presidential Commission for the Study of Bioethical Issues, particularly the historical importance of the Guatemala syphilis experiments that added a new chapter to the history of medicine and bioethics. He also touches on the ethical implications of neuroscience advancements, such as brain organoids and synthetic brains. Moreno concludes with reflections on the importance of bioethics in a rules-based international order and his contributions to the field through accessible writing and diverse kinds of academic work and public facing endeavors