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Integrating Neurosymbolic AI in Advanced Air Mobility: A Comprehensive Survey
No full textIJCAI 2025, the 34th International Joint Conference on Artificial Intelligence, Montreal, Canada, August 16 - August 22, 2025Neurosymbolic AI combines neural network adaptability with symbolic reasoning, promising an approach to address the complex regulatory, operational, and safety challenges in Advanced Air Mobility (AAM). This survey reviews its applications across key AAM domains such as demand forecasting, aircraft design, and real-time air traffic management. Our analysis reveals a fragmented research landscape where methodologies, including Neurosymbolic Reinforcement Learning, have shown potential for dynamic optimization but still face hurdles in scalability, robustness, and compliance with aviation standards. We classify current advancements, present relevant case studies, and outline future research directions aimed at integrating these approaches into reliable, transparent AAM systems. By linking advanced AI techniques with AAM's operational demands, this work provides a concise roadmap for researchers and practitioners developing next-generation air mobility solutions.This material is based upon work supported by the NASA Aeronautics Research Mission Directorate (ARMD) University Leadership Initiative (ULI) under cooperative agreement number 80NSSC23M0059. This research was also partially supported by the U.S. National Science Foundation through Grant No. 2317117 and Grant No. 2309760.http://arxiv.org/abs/2508.0716
Late-time Radio Brightening and Emergence of a Radio Jet in the Changing-look AGN 1ES 1927+654
No full textWe present multifrequency (5–345 GHz) and multiresolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic nuclei (CL-AGNs). The source was first designated a CL-AGN after an optical outburst in late 2017 and has since displayed considerable changes in X-ray emission, including the destruction and rebuilding of the X-ray corona in 2019–2020. Radio observations prior to 2023 show a faint and compact radio source typical of a radio-quiet AGN. Starting in 2023 February, 1ES 1927+654 began exhibiting a radio flare with a steep exponential rise, reaching a peak 60 times previous flux levels, and has maintained this higher level of radio emission for over a year to date. The 5–23 GHz spectrum is broadly similar to gigahertz-peaked radio sources, which are understood to be young radio jets less than ∼1000 yr old. Recent high-resolution Very Long Baseline Array observations at 23.5 GHz now show resolved extensions on either side of the core, with a separation of ∼0.15 pc, consistent with a new and mildly relativistic bipolar outflow. A steady increase in the soft X-ray band (0.3 2 keV) concurrent with the radio may be consistent with jet-driven shocked gas, though further observations are needed to test alternate scenarios. This source joins a growing number of CL-AGNs and tidal disruption events that show late time radio activity, years after the initial outburst.MN is supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 948381) and by UK Space Agency Grant No. ST/Y000692/1.https://iopscience.iop.org/article/10.3847/2041-8213/ad865
Hybrid Ensemble Deep Graph Temporal Clustering for Spatiotemporal Data
No full textThe increasing complexity of multidimensional spatiotemporal data presents significant challenges for clustering techniques, particularly in capturing intricate temporal, spatial, and heterogeneous patterns. This paper proposes a novel Hybrid Ensemble Deep Graph Temporal Clustering (HEDGTC) algorithm that integrates homogeneous and heterogeneous ensemble clustering models, leveraging both traditional and deep learning-based clustering approaches. The algorithm utilizes graph neural networks (GNNs) to effectively combine the strengths of multiple clustering models and enhance the clustering performance. The ensemble models are designed to handle diverse data characteristics, while the deep learning components capture complex non-linear relationships within the data. GNNs are employed to derive the final clustering outcomes by preserving spatial and temporal dependencies, making the approach well-suited for complex multidimensional spatiotemporal data. Experimental results from three real-world multivariate spatiotemporal data demonstrate the effectiveness of HEDGTC in accurately clustering and analyzing spatiotemporal patterns, outperforming state of the art ensemble models as well as traditional and individual deep clustering methods in terms of clustering performance and accuracy. The proposed method offers a robust framework for a wide range of applications, including climate modeling, geospatial analysis, and dynamic system forecasting.This work was supported by iHARP: NSF HDR Institute for Harnessing Data and Model Revolution in the Polar Regionshttps://ieeexplore.ieee.org/document/1082587
Does secure land tenure save forests? A review of the relationship between land tenure and tropical deforestation.
No full texthttps://liberiafti.wordpress.com/wp-content/uploads/2013/08/robinson_does-secure-land-tenure-save-forests-a-review-of-the-relationship-between-land-tenure-tropical-deforestation.pd
AstroPix: A Pixelated HVCMOS Sensor for Space-Based Gamma-Ray Measurement
No full textA next-generation medium-energy gamma-ray telescope targeting the MeV range would address open questions in astrophysics regarding how extreme conditions accelerate cosmic-ray particles, produce relativistic jet outflows, and more. One concept, AMEGO-X, relies upon the mission-enabling CMOS Monolithic Active Pixel Sensor silicon chip AstroPix. AstroPix is designed for space-based use, featuring low noise, low power consumption, and high scalability. Desired performance of the device include an energy resolution of 5 keV (or 10% FWHM) at 122 keV and a dynamic range per-pixel of 25-700 keV, enabled by the addition of a high-voltage bias to each pixel which supports a depletion depth of 500 um. This work reports on the status of the AstroPix development process with emphasis on the current version under test, version three (v3), and highlights of version two (v2). Version 3 achieves energy resolution of 10.4 +\- 3.2 % at 59.5 keV and 94 +\- 6 um depletion in a low-resistivity test silicon substrate.This work is funded in part by 18-APRA18-0084 and 20-RTF20-0003 and is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, and Laboratory Directed Research and Development (LDRD) funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U. S. Department of Energy under Contract No. DE-AC02-06CH11357. ALS and DV acknowledge that research was sponsored by NASA through a contract with ORAU. KK and ZM acknowledge that this material is based upon work supported by NASA under award number 80GSFC21M0002. YS’s work was supported by JSPS KAKENHI, Japan, Grant Numbers JP23K13127.http://arxiv.org/abs/2501.1169
Adaptive Numerical Differentiation for Extremum Seeking with Sensor Noise
No full textExtremum-seeking control (ESC) is widely used to optimize performance when the system dynamics are uncertain. However, sensitivity to sensor noise is an important issue in ESC implementation due to the use of high-pass filters or gradient estimators. To reduce the sensitivity of ESC to noise, this paper investigates the use of adaptive input and state estimation (AISE) for numerical differentiation. In particular, this paper develops extremum-seeking control with adaptive input and state estimation (ESC/AISE), where the high-pass filter of ESC is replaced by AISE to improve performance under sensor noise. The effectiveness of ESC/AISE is illustrated via numerical examples.This research supported in part by NSF grant CMMI 2031333.http://arxiv.org/abs/2501.0427
Connecting energetic electrons at the Sun and in the heliosphere through X-ray and radio diagnostics
No full textSolar flares release huge amounts of energy, a considerable part of which is channeled into particle acceleration in the lower corona. Hard X-ray (HXR) emissions are used to diagnose the accelerated electrons that bombard the chromosphere, while type III radio bursts result from energetic electron beams propagating through the corona and into interplanetary space. The Solar Orbiter mission, launched in 2020, aims to link solar flare remote observations with heliospheric events, thus producing useful observations for our understanding of particle acceleration and propagation from the Sun to the heliosphere. While both hard X-Ray and radio emissions result from flare-accelerated electrons, their relationship is not straightforward. By comparing the evolution of the X-ray emitting sites and the timing of type III bursts, our aim is to determine the conditions for associations between X-ray flares and interplanetary (IP) type III bursts. We analyzed 15 interplanetary type III bursts that are associated with HXR bursts in the first available period for simultaneous X-ray/radio observations of type III bursts from Solar Orbiter (using the RPW and STIX instruments). X-ray imaging was performed around the onset of the type III bursts, complemented by EUI 174 A images to assess the magnetic configuration of the corona. All 15 X-ray flares originated from the same active region on the west limb as observed by Solar Orbiter. In each of the events, a change in X-ray source morphology occurred shortly (<6 minutes) before the onset of type III radio bursts, indicating a change in the electron acceleration region preceding the radio emission. Considering the delays observed between the two emissions, these findings describe complex scenarios with multiple reconnection episodes, some of which may allow accelerated electrons to escape into IP space when open magnetic field lines are involved (interchange reconnection). In some cases, X-ray source elongations toward open field lines in the UV were observed, reinforcing this idea.Solar Orbiter is a mission of international cooperation between ESA and NASA, operated by ESA. The STIX instrument has been funded by the Swiss Space Office, the Polish National Science Centre, Centre national d’études spatiales (CNES), Commissariat à l’énergie atomique et aux énergies alternatives (CEA), the Czech Ministry of Education, Deutsches Zentrum für Luft- und Raumfahrt (DLR), the Austrian Space Programme, ESA PRODEX, the Agenzia Spaziale Italiana (ASI) and the Istituto Nazionale di Astrofisica (INAF). The RPW instrument has been designed and funded by CNES, the Centre National de la Recherche Scientifique (CNRS), the Paris Observatory, the Swedish National Space Agency, ESA PRODEX, and the participating institutes. We extend our gratitude to both the STIX and RPW teams for their assistance in this work. DP, NV and MM acknowledge support from the CNES for the participation to the solar Orbiter project and the support of the Fondation CFM pour la Recherche. The authors would like to thank the referee for his useful commments which largely improved the present paperhttps://www.aanda.org/component/article?access=doi&doi=10.1051/0004-6361/20245227
Mapping Venus’s Gravity Field with the VERITAS Mission
No full textThe Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy (VERITAS) mission, selected by the NASA Discovery program in 2021, addresses crucial scientific questions about Venus’s evolution, structure, and past and ongoing geological processes. The high-resolution mapping of the gravity field of the planet will give an essential contribution to meet the science objectives of the mission and to further our understanding of Venus. The VERITAS gravity science experiment will enable a gravity map of the planet with substantially higher and more uniform spatial resolution with respect to Magellan. This is achieved thanks to the near-polar, near-circular, lowaltitude orbit (~220 km), and the state-of-the-art quality of Doppler tracking data, collected from two separate and coherent radio links at X and Ka band. Our numerical simulations show that the VERITAS gravity science experiment can robustly fulfill the scientific requirements, achieving a gravity field spatial resolution ranging from 85 to 120 km. Across 90% of the planet, a spatial resolution better than 106 km is expected. Additionally, VERITAS can retrieve crucial parameters required to derive the tidal response and rotational state of Venus, thereby improving our understanding of the planet’s interior structure.This is VERITAS contribution No. 4. This work was supported in part by the Italian Space Agency under grant No. 2022–15-HH.0. This research was partially conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract (VERITAS, 80NM0020F0035) with the National Aeronautics and Space Administration. Work by G. C. was supported by NASA under award No. 80GSFC24M0006 via the VERITAS project.https://iopscience.iop.org/article/10.3847/PSJ/ad991a/met
Designing Multi-modal Timeline Interfaces to Make Conscious Decisions About Alcohol Intake
No full textM.S. -- The University of Baltimore, 2024Thesis submitted to the Yale Gordon College of Arts and Sciences of The University of Baltimore in partial fulfillment of the requirements for the degree of Master of Science in Interaction Design and Information ArchitectureAt a time when voice and chat technologies continue to find niches in digital, what tools can be available to people who seek support with reducing alcohol intake? Recent research on smartphone sensing to track alcohol recommends taking a social context approach to address public health hazards of drinking, while many current digital services require self-reporting. Focusing on two audiences, one who wants abstinence, and one that desires to reduce drinking, it is clear that many solutions focus on an abstinence focused approach. Medical practitioners recommend solutions that take a more phased approach to reducing alcohol usage. Traditional programs to reduce drinking in digital technologies focus on cessation and quitting permanently over a phased or reflective approach to reducing alcohol intake. Understanding how communities that experience minority stress, specifically bisexual individuals, can inform ideas of how to create new social spaces that decrease interpersonal stress. What can happen with a timeline, which typically focuses on quantitative metrics, to a solution that focuses more on modulating and thinking through alcohol usage. And, as AI assistants now can get built in code with tools like Claude and ChatGPT. Traditional biometrics like breathalyzers give personalized feedback; how can this evolve into a digital interface that tracks this data over time, and in a private and safe way in a digital interface
High-Frequency Power Spectrum of AGN NGC 4051 Revealed by NICER
No full textVariability studies offer a compelling glimpse into black hole dynamics, and Neutron Star Interior Composition Explorer's (NICER's) remarkable temporal resolution propels us even further. NICER observations of an active galactic nucleus (AGN), NGC 4051, have charted the geometry of the emission region of the central supermassive black hole. Our investigation of X-ray variability in NGC 4051 has detected extreme variations spanning a factor of 40–50 over a mere 10–12 hr. For the first time, we have constrained the X-ray power spectral density (PSD) of the source to 0.1 Hz, corresponding to a temporal frequency of 10⁴ Hz in a galactic X-ray binary with a mass of 10 M⊙. No extra high-frequency break/bend or any quasiperiodic oscillations are found. Through detailed analysis of energy-dependent PSDs, we found that the PSD normalization, the high-frequency PSD slope, as well as the bending frequency remain consistent across all energies within the 0.3–3 keV band, revealing the presence of a constant temperature corona. These significant findings impose critical constraints on current models of X-ray emission and variability in AGN.https://iopscience.iop.org/article/10.3847/2041-8213/adace