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Neuromorphic Processing on Event-Based Time-Series
No full textThis thesis provides an in-depth exploration of neuromorphic engineering, focusing on the pivotal role of neural spikes in biological and synthetic systems. In particular, this work challenges the favoring of non-biological over biologically plausible algorithms in technological development, advocating for the importance of spikes as primary information vectors. I begin by detailing neural models, like integrate-and-fire and the Mihalaș-Niebur (MN or GLIF) neurons, which serve as fundamental computational components in neuromorphic computing. I then demonstrate the aforementioned neural dynamics by synthesizing a 20-channel MEA cervical vagus nerve (VN) dataset using a 1000-input Spiking Neural Network (SNN). Using synaptic learning methods such as STDP, the labeled neurons were then clustered and classified into 30 distinct groups using a subsequent 3-layer SNN. To reduce unnecessary neural recording data and demonstrate neuromorphic interoperability, I then propose an adapted dynamic group sparsity algorithm which compresses recordings in real-time, predicated on a grouping theory among neurons. This method achieves nearly 98% signal recovery with over 90% compression on two separate VN datasets - surpassing existing methods.
Moreover, the thesis explores event-based (neuromorphic) imagers as analog sources for biologically-inspired spikes. First, I introduce a simulator that converts static images to spike data. This facilitates large spike-based dataset creation by avoiding time-consuming experimental setups. The tool was validated with MNIST and CALTECH-101 datasets using MN-based SNNs and advanced learning algorithms, like surrogate gradient descent. Using actual event-based recordings, I went on to design a spike-based visual saliency algorithm using ensemble learning to inform attention mechanisms over indefinitely long periods. I validated the algorithm by building a unique spike-based eye fixation dataset from 30 participants. Statistical tests confirm the algorithm's efficacy as well as confirming the datasets statistical significance. Overall, this dissertation underscores the criticality of neural spikes for enhancing data processing and learning while providing quantitative evidence of the advantages of spike-based technologies
Truth x Beauty
No full textThis thesis is a collection of nonfiction articles, reported essays and poems, plus one excerpt from a book manuscript. The subject matter ranges from the subatomic (nuclear fusion) and molecular (the chemical dynamics of tooth enamel) to the botanical (rose breeding), historical (life in the early 1800s), and philosophical (the value we place on truth). The largest segment of this thesis—the book excerpt—is also prescriptive, with research-backed advice and interactive exercises. Interspersed are some lyrical musings on the joy of experiencing the world through a scientific lens
A REVIEW OF METHODOLOGIES AND APPROACHES FOR CREATING SUCCESSFUL GHG INVENTORIES AND CLIMATE ACTION PLANS IN THE INDIAN HEALTHCARE SECTOR
Get PDFClimate change is one of the biggest public health threats in terms of both health impacts and disruptions to healthcare systems. The healthcare system globally is responsible for 6% of CO2e emissions (Karliner, Josh, Slotterback et al. 2020a), which puts it at odds with its mission to improve the health of individuals and communities. This creates an opportunity for healthcare institutions to provide leadership in future decarbonization efforts.
This report collaborated with a medium-sized hospital in Udupi, India, and multiple non-profit organizations to evaluate a Greenhouse Gas (GHG) inventory created as part of the United Nations Framework Convention on Climate Change (UFCCC) Race to Zero campaign. It also provides comparative case studies with institutes in India and the U.S. Additional report outputs include a climate action plan, identification of resources, and documentation of lessons learned for future healthcare GHG inventories in India.
Results indicate that creating an accurate and actionable GHG inventory at this type of institution is feasible using publicly available information and no-cost tools. However, questions about the accuracy and ability to create useful actions from Scope 3 spend-based supply chain analysis were identified
AN ANALYSIS OF COASTAL ADAPTATION EFFORTS IN BANGLADESH, VIETNAM, AND THE NETHERLANDS
Get PDFThe research undertaken in this paper takes a close look at low-lying vulnerable deltas, and hypothesizes that innovative Nature-based solutions (NBS) comprising ecosystem-based approaches, and integrated management of resources, can prove more beneficial than hard structural engineering solutions, in coastal adaptation efforts. The paper also seeks to observe whether policy planning and institutional efforts are aligned with the global sustainability agenda and are conducive to enhancing adaptive capacity. Vulnerable deltas globally, are identified for the selection of 3 case studies, through a range of biophysical and population indicators. Based on the 3 case studies of Netherlands, Bangladesh and Vietnam, the paper observes the structure of adaptation planning and implementation efforts, by local, national and global agencies, especially in areas of ecosystem-based approaches. A key objective is also to better understand what factors can cause adaptive capacity, and adaptation efforts, in deltas, to vary
DIVERSITY IN SCIENCE: IDENTITY, EDUCATION, AND THE WORLD AROUND US
Get PDFThe world would be boring if everything and everyone were the same. Diversity gives us new perspectives, opportunities to learn, and a vibrant and resilient ecosystem to live in. This is especially true in science. Diversity in Science: Identity, Education, and the World Around Us highlights and celebrates the heterogeneity found in the scientific world. It explores the topics I’ve been drawn to and the experiences I’ve had during my time in the Johns Hopkins University Science Writing Program. It reflects how I see the world
Oral History Interview with R. Alta Charo
No full textThis interview was conducted remotely with R. Alta Charo, JD, 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. She is the Warren P. Knowles Professor Emerita of Law and Bioethics at the University of Wisconsin, Madison. Her areas of expertise include policy, regulation, and funding
related to genetics, stem cell research, reproductive technologies, and human subjects research. She has authored or contributed to over 150 articles, book chapters, and government reports and has consulted on gene therapy and genome editing in medical and environmental applications for various pharmaceutical, gene therapy, xenotransplant, infertility therapy, and conservation genetics companies.
Charo recounts her immigrant family’s experiences in Brooklyn’s Flatbush neighborhood and her public-school education before leaving for Harvard University and then Columbia Law School. Charo discusses her early career in environmental law, her work at the Legislative Drafting Research Fund and at the Office of Technology Assessment. She shares the story of her appointment at the University of Wisconsin Law School and her expanding experience as a bioethics-focused policy expert. She discusses her work in the 1990s on President Clinton’s National Bioethics Advisory Commission when the sheep “Dolly” was cloned, and a few years later as a member of the NIH Human Embryo Research Panel, when publicity and politics highlighted the challenges of bioethics in the public sphere. Charo describes “bio-optimists” and “bio-pessimists” as a way to think about divisions among bioethicists and emphasizes the importance she places on balancing optimism and caution in technological advancements, citing Star Trek as an important influence. She discusses the role of law and regulation in guiding technology's use, the importance of public education about genetics, the complexities of end-of-life decisions, and the need for personalized medical care.
The conversation concludes with reflections on her committee work related to IVF, genome editing, the national security implications of biotech and bioterrorism, and the role of ethicists in helping society clarify current issues in bioethics
An Evaluation of the Summerbell Reading Program in Pennsylvania
Get PDFThis report summarizes the findings of an evaluation of the Summerbell Reading program as implemented in the East Stroudsburg Area School District (ESASD) in Pennsylvania. Conducted by Johns Hopkins University’s Center for Research and Reform in Education (JHU CRRE), this mixed-methods evaluation sought to assess students’, teachers’, and school leaders’ perceptions of the program after it was implemented in schools during the second half of the 2023-24 school year, and also sought to assess the extent to which the presence of this supplemental reading application may have fostered differential reading outcomes for students with dyslexia. In brief, Summerbell Reading is a digital reading application that adapts the visual presentation of text in ways that are hypothesized to potentially improve the ease in which some students with dyslexia may visually process writing. This reading application was provided to select third, fourth, and fifth grade students in the district struggling with dyslexia who then used the program as an instructional accommodation to assist with independent reading throughout the spring of 2024. To explore the impact of this intervention, the research team interviewed participating ESASD students, teachers, school leaders, and district leaders and observed classrooms while students utilized the application. Surveys were also administered to teachers and students to gather program feedback, and student achievement scores on the Acadience Reading Assessment were gathered and analyzed to examine student growth trends relative to other similar students in the district.
Overall, findings from this research demonstrated support for the program’s potential utility in enhancing reading outcomes for select students with dyslexia, while also pointing to the key factors and considerations that will dictate the program’s success in schools moving forward. Key findings from these data collection activities are highlighted below and are summarized in detail throughout this report:
- Teachers viewed the program as having a noticeable positive impact on the reading fluency of the majority of students assigned to the intervention, and many teachers highlighted specific student instances where the program appears to be
particularly impactful. Students were able to navigate the application with little difficulty and most students expressed that they felt using the program’s “positional reading arc” improved both the ease and speed in which they could read.
- Exploratory analyses of student achievement trends on the Acadience early literacy assessment found that students with dyslexia assigned to use the application demonstrated greater reading fluency gains in the Spring of 2024 compared to other ESASD elementary school students with this disability.
- Valuable lessons learned from ESASD’s pilot implementation of the program are also provided. These include key insights concerning how the program can be employed as part of a district’s Response to Intervention (RTI) framework, as well as lessons highlighting specific areas for future program development and technical refinement that may enhance program performance and usability with a variety of other digital materials
Restitution, Reconciliation, and Reparations for Namibia : Does International Law Provide a Right to Restorative Justice?
Get PDFhttps://mediahost.sais-jhu.edu/saismedia/media/web/files/2024-report-final.pdfFrom January 13-20, 2024, 12 Johns Hopkins SAIS students and one faculty member travelled to Namibia as part of the school’s International Human Rights Law Clinic. This long-standing experiential learning course is a practicum designed to provide hands-on experience in legal mechanisms for the promotion and protection of internationally guaranteed human rights.
With different destinations and topics each year, this year’s focus on Namibia studies the question of what, if anything, international law has to say about restorative justice.
“Two ethnic groups in what is now Namibia were the victims of a genocide perpetrated during the first decade of the 20th century, when Germany was the colonial power over the territory,” said Steven Schneebaum, lawyer, adjunct lecturer of international law, and faculty leader of the International Human Rights Law Clinic. “In recent times, the Namibian and German governments have attempted to arrive at a mutually satisfactory way of providing restorative justice, but the solutions proposed so far have not received the support of descendants of the victimized groups. We are studying this situation and hope to understand not only what has happened and is happening in Namibia, but to draw some lessons that may be applicable elsewhere.
DAYS TOGETHER, FOR THE MOMENT SHORT STORIES
Get PDFI had an unplanned yet extremely rewarding profession in child welfare engaging with families. At the onset of my career, I shared many milestones with the parents, and now the mothers and fathers I come across are the age of my children. With the passing of time, I realized child welfare is a story about people, and everyone has a story. Time and again the trajectory of their lives unexpectedly shifts. Drawing inspiration from these interactions “Days Together, for the Moment” presents fictional stories about individuals existing and coping with their personal lives
THE FUTURE OF HYDROPOWER IN THE COLUMBIA RIVER BASIN
Get PDFHydropower has been the backbone of electricity generation in the Pacific Northwest for decades, providing clean and affordable energy for millions of residents each year. That being said, hydropower’s presence and effectiveness in the Columbia River Basin is threatened by numerous environmental, technical, and social factors. While hydroelectric generation inherently experiences significant variations in energy and capacity depending on the season as well as on a year to year basis, climate change is expected to exacerbate this seasonality by altering regional temperatures, precipitation patterns, and the timing and intensity of streamflows.
Additionally, the ongoing impact of the presence of dams in the Columbia River Basin on native anadromous fish populations and Indigenous communities has the potential to influence the removal of some hydroelectric projects. The depletion of salmon populations and habitats have led many local species to be labeled as endangered with the continued existence of dams threatening their long-term survival. Closely tied to the survival of the basin’s salmon populations is the cultural, spiritual, and economic wellbeing of Indigenous communities. From flooded lands to the destruction of fishing and hunting areas explicitly outlined in their treaties with white settlers, Indigenous communities continue to endure a disproportionate amount of the burden associated with hydroelectric infrastructure, warranting tangible solutions potentially through dam removal.
Furthermore, changes in regional energy demand as well as additional wind and solar deployment could impact the portion of demand met by hydropower. These topics will be explored through an extensive literature review, outlining some of the major challenges that hydroelectric generation in the Columbia River Basin will face throughout the 21st century