22689 research outputs found
Sort by
Oral History of Monica Yorkman
No full textThis oral history about transgender experience in Baltimore was recorded as part of Vintage T, a public humanities project led by Monica Stevens, Jamie Grace Alexander, and Rahne Alexander and sponsored by Sistas of the “T” and the Winston Tabb Special Collections Research Center. Vintage T was launched in 2023 to document and archive the perspectives, strategies, and personal histories of trans individuals in Baltimore, thereby preserving valuable traditions within trans communities
Oral History of Shawna Alexander
No full textThis oral history about transgender experience in Baltimore was recorded as part of Vintage T, a public humanities project led by Monica Stevens, Jamie Grace Alexander, and Rahne Alexander and sponsored by Sistas of the “T” and the Winston Tabb Special Collections Research Center. Vintage T was launched in 2023 to document and archive the perspectives, strategies, and personal histories of trans individuals in Baltimore, thereby preserving valuable traditions within trans communities
A COMPARITIVE ANALYSIS OF ENERGIZE CONNECTICUT AND MASS SAVE ENERGY EFFICIENCY PROGRAMS
No full textThe United States is projected to see an increase of as much as 15% in energy consumption by 2050 because of the push toward electrification and additional needs for heating and cooling (U.S. Energy Information Adminstration, 2023). Utility administered energy efficiency programs across the country have successfully saved Americans money while reducing the demand on the electrical grid. The programs in Connecticut and Massachusetts are top producers among the country’s efficiency programs. Comparison of the two programs’ budgets, account usage and savings results reveal many similarities, however differences in funding mechanisms result in Mass Save in Massachusetts having greater financial resources than Connecticut’s Energize Connecticut program despite being similar sized states. Additionally, Massachusetts has created legislation that mandates municipalities implement energy saving measures and take steps to bolster clean energy generation. Additionally, Massachusetts offers funding directly to their municipalities to aid in these goals. Energize Connecticut would benefit from additional funding and would have higher program usage if their municipalities were similarly mandated
IN MOTION ON MOVING WITH THE WIND AND MOVING GLACIERS
No full text“Linger” is a word that sounds like its meaning. The “ger” at the end is a syllable that softly fades. The end to lingering is movement. What I’ve written about here—soundscape ecology, sunsets, body parts preserved in museum display jars, and glaciers—are topics that preoccupied me before finally appearing as paragraphs and pages. They carry with them memories and history as much as they do movement and change.
This collection begins by the sea and ends in the mountains. It begins with a place I keep close and ends somewhere far from where I am now. In between these pieces and places are stories of science and people and our past and present. I hope this collection moves you, as its subjects have moved me
OUR MATERIAL WORLD HOW MATERIALS INFLUENCE SCIENCE AND SOCIETY
No full textAtoms are impactful at any scale. Millions of subatomic particles drift through space, invisible to the naked eye, and yet they shape our existence. Probing the behavior of matter is vital to understanding everything from revolutionary scientific discoveries to mere moments of happenstance in our mundane lives.
In this collection of stories, atoms—and the materials they form—play a central role
NATURE AND HEALTH ARTICLES AND ESSAYS ON ENVIRONMENTAL AND MEDICAL ISSUES
No full textMuch of my early career in public relations has involved fielding clients’ requests and writing content to align with a communication strategy. JHU’s Science Writing program has granted me the simple pleasure of exploring any science stories that interest me. Eager and unfettered, I tread across diverse terrains of subject matter, from how nature and people interact to how societal structures impact human health. This thesis assembles stories that most delighted and challenged me. Nearly every piece arose from unassuming, everyday experiences, such as pulling weeds, chatting with a close friend, or donating blood. Once dissected, however, commonplace encounters become on-ramps for exploring important issues: nature conservation, gender-affirming care, and national blood supply shortages. Before long, one begins to see the story in every moment
A GAIN-SCHEDULED CONTROL SCHEME FOR IMPROVED MANEUVERABILITY AND POWER EFFICIENCY OF UNDERWATER GLIDERS
No full textUnderwater gliders are a relatively new type of low-power, long duration underwater
vehicle that use changes in buoyancy to propel themselves forward. They are widely
used today for oceanographic research, and a number of theoretical control schemes
have been derived over the years. However, despite their nonlinear dynamics that
evolve as a function of their environment and operating conditions, most fielded
gliders use linear control methods, such as static-gain proportional-integral (PI) or
proportional-integral-derivative (PID) compensators for motion control, which can
significantly limit vehicle performance.
This thesis develops an alternative approach to underwater glider control that employs
control system gain-scheduling to improve vehicle performance and efficiency over a
wider range of operating conditions as compared to static or fixed-gain approaches. The
primary contribution of this thesis is the development of a practical gain-scheduling
procedure using linearized models of the decoupled pitch and yaw dynamics of the
vehicle. This methodology improves on the current fixed-gain topologies used on
fielded gliders today, while being straightforward and cost-effective to implement.
In this thesis, the development of a nonlinear dynamical model of a Slocum glider using
computer-aided design (CAD) and computational fluid dynamics (CFD) simulations
was also carried out to support the high-fidelity characterization of the controller
topologies. A nonlinear numerical simulation of the Slocum glider was developed in Matlab and was used to assess the performance improvements and the increased
robustness of the gain-scheduled PID method to a standard fixed-gain PID approach
BLACK HOLES AND BUBBLES OF NOTHING: EXPLORATIONS IN EXACTLY SOLVABLE SECTORS OF GRAVITY
No full textThe nonlinearity of Einstein’s equations makes the identification of exact solutions in theories of gravity a formidable challenge. However, there exist sectors of gravitational theories in which the equations of motion reduce to a simpler system of coupled PDEs, or even linearize. It is the identification of these exactly solvable sectors, via a suitable ansatz for the spacetime metric and matter fields, which historically facilitated the discovery of exact solutions describing ultra-compact massive objects. In addition to black hole solutions, in more than four spacetime dimensions these can exist smooth and horizonless topological solitons. Black hole solutions and topological solitons are central to the effort to reconcile general relativity with quantum physics. While many of these solutions have been studied for decades, there is still much we do not understand, and exact solutions for certain classes of ultra-compact objects continue to elude us.
In this thesis, we explore two particularly rich sectors of gravity using the Kerr-Schild ansatz and the Weyl ansatz. The linearity of Einstein’s equations with the Kerr-Schild ansatz allows solutions to be mapped to corresponding solutions in gauge theory, using the classical double copy. We refine this correspondence, and demonstrate its use as a solution generating technique to reproduce asymptotically flat four-dimensional black hole solutions from complexified Lienard-Wiechert solutions in Maxwell theory. For four or more dimensions, we are able to extend the double copy correspondence to many new classes of black holes, and use it furnish a test for Kerr-Schild structure in solutions of arbitrary dimension.
The Weyl ansatz is the second we employ, to explore a sector in which the Einstein equations in four or more dimensions decompose to a collection of four-dimensional equations of motion. By restricting to static and axisymmetric solutions, this decomposition allows us to make use of exact solutions describing bound states of dyonic black holes in four-dimensions. Inspired by these solutions, we construct the first examples of neutral topological solitons supported by internal fluxes. This result marks an important step toward a geometric description of the microstates of the Schwarzschild black hole
COMPUTATIONAL STATUTORY REASONING
No full textStatutory reasoning is the task of determining how laws apply to a legal case. This is a basic skill for lawyers, and in its computational form, a fundamental task for legal Artificial Intelligence (AI) systems. In this thesis, I take a first step towards solving computational statutory reasoning.
First, I define computational statutory reasoning, in the context of legal practice, and AI more broadly (Chapter 1). I detail why statutory reasoning is important for legal AI, and how solving it will require addressing multiple problems in general AI research. In Chapter 2, I review research in reasoning, knowledge representation and legal AI that is relevant to the work in this thesis.
My first contribution is the StAtutory Reasoning Assessment dataset (SARA), a benchmark dataset for computational statutory reasoning (Chapter 3). With the ability to measure performance on statutory reasoning, I show how a symbolic system can solve the SARA dataset, while state-of-the-art Machine Reading (MR) struggles.
In Chapter 4, I connect statutory reasoning to established natural language processing tasks, in an attempt to diagnose MR errors. This yields more annotations on SARA, and a performance boost compared to my initial MR baselines. In Chapter 5, I return to the symbolic approach of Chapter 3. Revising the ontology used in Chapter 3, I introduce models for Information Extraction (IE) from SARA cases. The attained performance opens up new perspectives on how to solve statutory reasoning.
I close by summarizing the contributions of this thesis, and expanding on possible future research (Chapter 6)