MD-SOAR Maryland Shared Open Access Repository
Not a member yet
34521 research outputs found
Sort by
From Standard to Bayesian: Revisiting Ocean Color Model Evaluation
No full textOcean color models, facilitated by satellite-based remote sensing technologies, have transformed our ability to monitor chlorophyll-a concentrations at the ocean’s surface. These models decode changes in the spectral properties of reflected sunlight to map phytoplankton biomass across extensive spatial and temporal scales. Such capabilities are crucial for understanding marine primary productivity, carbon cycling, and ecosystem reactions to environmental change. Additionally, improvements in atmospheric correction and inwater algorithms over the past decades have reduced the uncertainties associated with chlorophyll-a retrieval, rendering satellite-derived ocean color data more suitable for fisheries management, climate research, and coastal water quality monitoring. However, the most commonly used ocean color products (e.g., Sentinel datasets) do not provide uncertainties, which poses challenges in their application for analyzing events like algal blooms and for risk assessment. Moreover, these models are typically evaluated using deterministic error metrics that may not always capture the subtleties in model performance. This paper presents a probabilistic alternative to traditional ocean color models, including the maximum band and color index models, utilizing Bayesian regression and underpinned by an exhaustive database of validated bio-optical match-ups. We further propose a method for comparing ocean color models using the Bayesian information criterion, which evaluates models more effectively by emphasizing those with minimal deviation and mean difference relative to reference measurements. Our findings indicate that, depending on the application, the commonly used OC4 model may not necessarily be the most effective option available.This research has been supported by the National Oceanic and Atmospheric Administration (US Department of Commerce grant no. NA18OAR4320123) and Princeton University through the Cooperative Institute for Modeling the Earth System. RB is supported by a UKRI FLF grant (MR/V022792/1https://essopenarchive.org/users/934008/articles/1304725-from-standard-to-bayesian-revisiting-ocean-color-model-evaluation?commit=45d047aec5ecdb2895ed748bc35ad53a577443b
Millihertz Oscillations Near the Innermost Orbit of a Supermassive Black Hole
No full textRecent discoveries from time-domain surveys are defying our expectations for how matter accretes onto supermassive black holes (SMBHs). The increased rate of short-timescale, repetitive events around SMBHs, including the newly-discovered quasi-periodic eruptions (QPEs), are garnering further interest in stellar-mass companions around SMBHs and the progenitors to mHz frequency gravitational wave events. Here we report the discovery of a highly significant mHz Quasi-Periodic Oscillation (QPO) in an actively accreting SMBH, 1ES 1927+654, which underwent a major optical, UV, and X-ray outburst beginning in 2018. The QPO was first detected in 2022 with a roughly 18-minute period, corresponding to coherent motion on scales of less than 10 gravitational radii, much closer to the SMBH than typical QPEs. The period decreased to 7.1 minutes over two years with a decelerating period evolution (). This evolution has never been seen in SMBH QPOs or high-frequency QPOs in stellar mass black holes. Models invoking orbital decay of a stellar-mass companion struggle to explain the period evolution without stable mass transfer to offset angular momentum losses, while the lack of a direct analog to stellar mass black hole QPOs means that many instability models cannot explain all of the observed properties of the QPO in 1ES 1927+654. Future X-ray monitoring will test these models, and if it is a stellar-mass orbiter, the Laser Interferometer Space Antenna (LISA) should detect its low-frequency gravitational wave emission.RA was supported by NASA through the NASA Hubble Fellowship grant #HST-HF2-51499.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. AI acknowledges support from the Royal Society. MG is supported by the 揚rograma de Atraccion de Talento� of the Comunidad de Madrid, grant number 2022-5A/TIC-24235. CP is supported by PRIN MUR SEAWIND funded by NextGenerationEU.http://arxiv.org/abs/2501.0158
On the Baltimore Light RailLink into the quantum future
No full textIn the current era of noisy intermediate-scale quantum (NISQ) technology, quantum devices present new avenues for addressing complex, real-world challenges including potentially NP-hard optimization problems. Acknowledging the fact that quantum methods underperform classical solvers, the primary goal of our research is to demonstrate how to leverage quantum noise as a computational resource for optimization. This work aims to showcase how the inherent noise in NISQ devices can be leveraged to solve such real-world problems effectively. Utilizing a D-Wave quantum annealer and IonQ’s gate-based NISQ computers, we generate and analyze solutions for managing train traffic under stochastic disturbances. Our case study focuses on the Baltimore Light RailLink, which embodies the characteristics of both tramway and railway networks. We explore the feasibility of using NISQ technology to model the stochastic nature of disruptions in these transportation systems. Our research marks the inaugural application of both quantum computing paradigms to tramway and railway rescheduling, highlighting the potential of quantum noise as a beneficial resource in complex optimization scenarios.B.G acknowledges support from the National Science Center (NCN), Poland, under Project No. 2020/38/E/ST3/00269. K.D acknowledges: Scientific work co-financed from the state budget under the program of the Minister of Education and Science, Poland (pl. Polska) under the name ”Science for Society II” project number NdS-II/SP/0336/2024/01 funding amount 1000000 PLN total value of the project 1000000 PLN. S.D. acknowledges support the John Templeton Foundation under Grant No. 62422. We acknowledge Swiftly’s GTFS-realtime API https://swiftly.zendesk.com/hc/en-us (accessed 11-31 January 2024) for supplying real-time traffic data. K.D. acknowledges cooperation with Koleje Slaskie sp. z o.o. (eng. Silesian Railways Ltd.) and appreciates the valuable and substantive discussions.https://www.nature.com/articles/s41598-025-15545-
What $2bn in Spending Cuts Looks Like
No full textFacing a fiscal crisis, MD Governor Wes Moore has proposed 2 billion look like to legislators beginning to hear from constituents and advocates? Sunil Dasgupta asks Maryland House Majority Leader David Moon and the Appropriations Committee member Emily Shetty to break down the cuts and put them into perspective. Newly in public domain music by Clara Smith and The Troubadours.https://open.spotify.com/episode/5zpDBDl9OXfoCLVxyn96i
Dynamic Imprints of Colliding-wind Dust Formation from WR 140
No full textCarbon-rich Wolf–Rayet (WR) binaries are a prominent source of carbonaceous dust that contribute to the dust budget of galaxies. The "textbook" example of an episodic dust-producing WR binary, WR 140 (HD 193793), provides us with an ideal laboratory for investigating the dust physics and kinematics in an extreme environment. This study is among the first to utilize two separate JWST observations, from Cycle 1 ERS (2022 July) and Cycle 2 (2023 September), to measure WR 140's dust kinematics and confirm its morphology. To measure the proper motions and projected velocities of the dust shells, we performed a novel point-spread function (PSF) subtraction to reduce the effects of the bright diffraction spikes and carefully aligned the Cycle 2 to the Cycle 1 images. At 7.7 μm, through the bright feature common to 16 dust shells (C1), we find an average dust shell proper motion of 390 ± 29 mas yr⁻¹, which equates to a projected velocity of 2714 ± 188 km s⁻¹ at a distance of 1.64 kpc. Our measured speeds are constant across all visible shells and consistent with previously reported dust expansion velocities. Our observations not only prove that these dusty shells are astrophysical (i.e., not associated with any PSF artifact) and originate from WR 140, but also confirm the "clumpy" morphology of the dust shells, in which identifiable substructures within certain shells persist for at least 14 months from one cycle to the next. These results support the hypothesis that clumping in the wind collision region is required for dust production in WR binaries.The work of E.P.L. is supported by NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the U.S. National Science Foundation. J.L.H. acknowledges support from the National Science Foundation under award AST-1816944. T.O. acknowledges support by the Japan Society for the Promotion of Science (JSPS) KAKENHI grant No. JP24K07087. N.D.R. is grateful for support from the Cottrell Scholar Award #CS-CSA-2023-143 sponsored by the Research Corporation for Science Advancement. J.S.-B. acknowledges the support received from the UNAM PAPIIT project IA 105023. C.M.P.R. acknowledges support from NASA Chandra Theory grant TM3-24001X. This material is based upon work supported by NASA under award number 80GSFC24M0006 and based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract number NAS 5-03127 for JWST. These observations are associated with programs #3823 and #1349. Support for program #3823 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. We thank the anonymous reviewer for insightful feedback that improved the quality of this manuscript. We thank Christopher Packham and Mason Leist for their valuable discussions about the MIRI PSF subtraction.https://iopscience.iop.org/article/10.3847/2041-8213/ad9aa
Compatibility of Quantum Measurements and the Emergence of Classical Objectivity
No full textThe study of measurements in quantum mechanics exposes many of the ways in which the quantum world is different. For example, one of the hallmarks of quantum mechanics is that observables may be incompatible, implying among other things that it is not always possible to find joint probability distributions which fully capture the joint statistics of multiple measurements. Instead, one must employ more general tools such as the Kirkwood-Dirac quasiprobability (KDQ) distribution, which may exhibit negative or nonreal values heralding nonclassicality. In this paper, we consider the KDQ distributions describing arbitrary collections of measurements on disjoint components of some generic multipartite system. We show that the system dynamics ensures that these distributions are classical if and only if the Hamiltonian supports quantum Darwinism. Thus, we demonstrate a fundamental relationship between these two notions of classicality and their emergence in the quantum world.https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.04221
Integrated Census and Origin-Destination (OD) Dataset for EV Charging Infrastructure Analysis in the Baltimore Metropolitan Statistical Area
No full textTo model the impacts of residential charging on commercial charging demand, the study employs Monte Carlo Simulation (MCS). This technique models stochastic EV charging demand using static travel demand and EV profiles, addressing the complexity and stochasticity arising from diverse travel patterns, EV characteristics, and charging infrastructure capacity. Before the data processing begins, the Round 10 Cooperative Forecast data and RITIS data are integrated with QGIS by matching the Traffic Analysis Zone (TAZ) IDs of both datasets to ensure spatial consistency. The key datasets include: Travel Demand Data, EV Profile Data, and Charging Infrastructure Capacity Data.This report focuses on the data and methodologies utilized to evaluate the impact of residential charging facilities on the demand for commercial charging infrastructure. The study uses the Baltimore-Columbia-Towson Metropolitan Statistical Area (MSA) as the study site, comprising six counties and one independent city (Anne Arundel, Baltimore City and County, Carroll, Harford, Howard, and Queen Anne’s), with a combined population of approximately 3 million
Improving spleen segmentation in ultrasound images using a hybrid deep learning framework
No full textThis paper introduces a novel method for spleen segmentation in ultrasound images, using a two-phase training approach. In the first phase, the SegFormerB0 network is trained to provide an initial segmentation. In the second phase, the network is further refined using the Pix2Pix structure, which enhances attention to details and corrects any erroneous or additional segments in the output. This hybrid method effectively combines the strengths of both SegFormer and Pix2Pix to produce highly accurate segmentation results. We have assembled the Spleenex dataset, consisting of 450 ultrasound images of the spleen, which is the first dataset of its kind in this field. Our method has been validated on this dataset, and the experimental results show that it outperforms existing state-of-the-art models. Specifically, our approach achieved a mean Intersection over Union (mIoU) of 94.17% and a mean Dice (mDice) score of 96.82%, surpassing models such as Splenomegaly Segmentation Network (SSNet), U-Net, and Variational autoencoder based methods. The proposed method also achieved a Mean Percentage Length Error (MPLE) of 3.64%, further demonstrating its accuracy. Furthermore, the proposed method has demonstrated strong performance even in the presence of noise in ultrasound images, highlighting its practical applicability in clinical environments.https://www.nature.com/articles/s41598-025-85632-
A Reference Architecture for Observability and Compliance of Cloud Native Applications
No full textThe evolution of cloud computing has given rise to Cloud Native Applications (CNAs), presenting new challenges in governance, particularly when faced with strict compliance requirements. This work explores the unique characteristics of CNAs and their impact on governance. We introduce a comprehensive reference architecture designed to streamline governance across CNAs along with a sample implementation, offering insights for both single and multi-cloud environments. Our architecture seamlessly integrates governance within the CNA framework, adhering to a "battery-included" philosophy. Tailored for both expansive and compact CNA deployments across various industries, this design enables cloud practitioners to prioritize product development by alleviating the complexities associated with governance. In addition, it provides a building block for academic exploration of generic CNA frameworks, highlighting their relevance in the evolving cloud computing landscape.https://arxiv.org/abs/2302.11617v
Consent and Trust: Concepts, History, Issues, and Research
No full textvideo file and slides from Consent and Trust presentation to CIVITAS Networks for Health members and the general public on 4/24/2025.D.P.A. -- The University of
Baltimore, 2025Project submitted to the College of Public Affairs of The University of
Baltimore in partial fulfillment of
the requirements for the degree
of Doctor of Public Administration.Webinar that outlines the foundational consent concepts and historical context of trust and consent. The presentation also discusses contemporary challenges in consent and the trust dynamics involved. The author presents Key findings from a cross-sectional analysis of consent-related documentation—including patterns, performance gaps, and areas of opportunity.CIVITAS Networks for Healthhttps://vimeo.com/1078467640/92a22630fa?share=cop