This study presents a comprehensive analysis of four significant California wildfires: Palisades, Eaton, Kenneth, and Hurst, examining their impacts through multiple dimensions, including land cover change, jurisdictional management, structural damage, and demographic vulnerability. Using the Chebyshev-Kolmogorov-Arnold network model applied to Sentinel-2 imagery, the extent of burned areas was mapped, ranging from 315.36 to 10,960.98 hectares. Our analysis revealed that shrubland ecosystems were consistently the most affected, comprising 57.4-75.8% of burned areas across all events. The jurisdictional assessment demonstrated varying management complexities, from singular authority (98.7% in the Palisades Fire) to distributed management across multiple agencies. A structural impact analysis revealed significant disparities between urban interface fires (Eaton: 9,869 structures; Palisades: 8,436 structures) and rural events (Kenneth: 24 structures; Hurst: 17 structures). The demographic analysis showed consistent gender distributions, with 50.9% of the population identified as female and 49.1% as male. Working-age populations made up the majority of the affected populations, ranging from 53.7% to 54.1%, with notable temporal shifts in post-fire periods. The study identified strong correlations between urban interface proximity, structural damage, and population exposure. The Palisades and Eaton fires affected over 20,000 people each, compared to fewer than 500 in rural events. These findings offer valuable insights for the development of targeted wildfire management strategies, particularly in wildland urban interface zones, and emphasize the need for age- and gender-conscious approaches in emergency response planning.
William Gantt, Alexander Martin, Pavlo Kuchmiichuk
et al.
We introduce event-keyed summarization (EKS), a novel task that marries traditional summarization and document-level event extraction, with the goal of generating a contextualized summary for a specific event, given a document and an extracted event structure. We introduce a dataset for this task, MUCSUM, consisting of summaries of all events in the classic MUC-4 dataset, along with a set of baselines that comprises both pretrained LM standards in the summarization literature, as well as larger frontier models. We show that ablations that reduce EKS to traditional summarization or structure-to-text yield inferior summaries of target events and that MUCSUM is a robust benchmark for this task. Lastly, we conduct a human evaluation of both reference and model summaries, and provide some detailed analysis of the results.
Liana Rauf, Cullan Howlett, Simon Stevenson
et al.
Gravitational waves (GWs) have revealed surprising properties of binary black hole (BBH) populations, but there is still mystery surrounding how these compact objects evolve. We apply Bayesian inference and an efficient method to calculate the BBH merger rates in the Shark host galaxies, to determine the combination of COMPAS parameters that outputs a population most like the GW sources from the LVK transient catalogue. For our COMPAS models, we calculate the likelihood with and without the dependence on the predicted number of BBH merger events. We find strong correlations between hyper-parameters governing the specific angular momentum (AM) of mass lost during mass transfer, the mass-loss rates of Wolf-Rayet stars via winds and the chemically homogeneous evolution (CHE) formation channel. We conclude that analysing the marginalised and unmarginalised likelihood is a good indicator of whether the population parameters distribution and number of observed events reflect the LVK data. In doing so, we see that the majority of the models preferred in terms of the population-level parameters of the BBHs greatly overpredict the number of events we should have observed to date. Looking at the smaller number of models which perform well with both likelihoods, we find that those with no CHE, AM loss occurring closer to the donor during the first mass-transfer event, and/or higher rates of mass-loss from Wolf-Rayet winds are generally preferred by current data. We find these conclusions to be robust to our choice of selection criteria.
To understand a document with multiple events, event-event relation extraction (ERE) emerges as a crucial task, aiming to discern how natural events temporally or structurally associate with each other. To achieve this goal, our work addresses the problems of temporal event relation extraction (TRE) and subevent relation extraction (SRE). The latest methods for such problems have commonly built document-level event graphs for global reasoning across sentences. However, the edges between events are usually derived from external tools heuristically, which are not always reliable and may introduce noise. Moreover, they are not capable of preserving logical constraints among event relations, e.g., coreference constraint, symmetry constraint and conjunction constraint. These constraints guarantee coherence between different relation types,enabling the generation of a uniffed event evolution graph. In this work, we propose a novel method named LogicERE, which performs high-order event relation reasoning through modeling logic constraints. Speciffcally, different from conventional event graphs, we design a logic constraint induced graph (LCG) without any external tools. LCG involves event nodes where the interactions among them can model the coreference constraint, and event pairs nodes where the interactions among them can retain the symmetry constraint and conjunction constraint. Then we perform high-order reasoning on LCG with relational graph transformer to obtain enhanced event and event pair embeddings. Finally, we further incorporate logic constraint information via a joint logic learning module. Extensive experiments demonstrate the effectiveness of the proposed method with state-of-the-art performance on benchmark datasets.
Event coreference models cluster event mentions pertaining to the same real-world event. Recent models rely on contextualized representations to recognize coreference among lexically or contextually similar mentions. However, models typically fail to leverage commonsense inferences, which is particularly limiting for resolving lexically-divergent mentions. We propose a model that extends event mentions with temporal commonsense inferences. Given a complex sentence with multiple events, e.g., "The man killed his wife and got arrested", with the target event "arrested", our model generates plausible events that happen before the target event - such as "the police arrived", and after it, such as "he was sentenced". We show that incorporating such inferences into an existing event coreference model improves its performance, and we analyze the coreferences in which such temporal knowledge is required.
The atomic-vapor cell is a vital component for Rydberg atomic microwave sensors, and impacts on overall capability of Rydberg sensor. However, the conventional analysis approach on effect of vapor-cell length contains two implicit assumptions, that is, the same atomic population density and buffer gas pressure, which make it unable to accurately capture actual response about effect of Rydberg-atom-based sensor performance on different Rydberg atom population. Here, utilizing a stepped cesium atomic-vapor cell with five different dimensions at the same atomic population density and buffer gas pressure, the height and full width at half maximum of Electromagnetically Induced Transparency(EIT) signal, and the sensitivity of the atomic superheterodyne sensor are comprehensively investigated at the same Rabi frequences(saturated laser power) conditions. It is identified that EIT signal height is proportional to the cell length, full width at half maximum and sensitivity grow with the increment of cell length to a certain extent. Based on the coherent integration signal theory and atomic linear expansion coefficient method, theoretical analysis of the EIT height and sensitivity are further investigated. The results could shed new light on the understanding and design of ultrahigh-sensitivity Rydberg atomic microwave sensors and find promising applications in quantum measurement, communication, and imaging.
Discovery of nine populations in a set of 193 select SOHO Kreutz sungrazers (Sekanina 2021) is confirmed for the first time via a histogram of the true longitudes of the ascending node, constructed for a revised set of 220 select sungrazers imaged exclusively by the SOHO's C2 coronagraph. Marsden's orbits are approximately corrected for effects of the out-of-plane nongravitational force. Population I displays two peaks in the histogram, one presumably belonging to a side branch alike to Population Pe, but with no related naked-eye sungrazer known. Swarms/clusters of objects are commonplace, providing evidence on cascading fragmentation proceeding throughout the orbit. Augmentation to all C2-only SOHO Kreutz comets, aimed at removing deliberate bias against Populations I and Pe, reduces the appearance of Populations Ia and Pre-I to bulges along the slope of the histogram because of the swollen wings of Populations I and Pe, respectively. Populations II through IV change very little or not at all. The high Population I-to-II abundance ratio, of 14:1, may be a product of temporal limitations in fragment release. A drop in the number of fragments toward the ends of the nodal-longitude distribution, especially from Population II to IV, is in line with the contact-binary model.
Christian N. Setzer, Hiranya V. Peiris, Oleg Korobkin
et al.
The 2017 detection of a kilonova coincident with gravitational-wave emission has identified neutron star mergers as the major source of the heaviest elements, and dramatically constrained alternative theories of gravity. Observing a population of such sources has the potential to transform cosmology, nuclear physics, and astrophysics. However, with only one confident multi-messenger detection currently available, modelling the diversity of signals expected from such a population requires improved theoretical understanding. In particular, models which are quick to evaluate, and are calibrated with more detailed multi-physics simulations, are needed to design observational strategies for kilonovae detection, and to obtain rapid-response interpretations of new observations. We use grey-opacity models to construct populations of kilonovae, spanning ejecta parameters predicted by numerical simulations. Our modelling focuses on wavelengths relevant for upcoming optical surveys, such as the Rubin Observatory Legacy Survey of Space and Time (LSST). In these simulations, we implement heating rates that are based on nuclear reaction network calculations. We create a Gaussian-process emulator for kilonova grey opacities, calibrated with detailed radiative transfer simulations. Using recent fits to numerical relativity simulations, we predict how the ejecta parameters from BNS mergers shape the population of kilonovae, accounting for the viewing-angle dependence. Our simulated population of binary neutron star (BNS) mergers produce peak i-band absolute magnitudes $-20 \leq M_i \leq -11$. A comparison with detailed radiative transfer calculations indicates that further improvements are needed to accurately reproduce spectral shapes over the full light curve evolution.
We model spatially expanding populations by means of two spatial $Λ$-Fleming Viot processes (or SLFVs) with selection: the k-parent SLFV and the $\infty$-parent SLFV. In order to do so, we fill empty areas with type 0 ''ghost'' individuals with a strong selective disadvantage against ''real'' type 1 individuals, quantified by a parameter k. The reproduction of ghost individuals is interpreted as local extinction events due to stochasticity in reproduction. When k $\rightarrow$ +$\infty$, the limiting process, corresponding to the $\infty$-parent SLFV, is reminiscent of stochastic growth models from percolation theory, but is associated to tools making it possible to investigate the genetic diversity in a population sample. In this article, we provide a rigorous construction of the $\infty$-parent SLFV, and show that it corresponds to the limit of the k-parent SLFV when k $\rightarrow$ +$\infty$. In order to do so, we introduce an alternative construction of the k-parent SLFV which allows us to couple SLFVs with different selection strengths and is of interest in its own right. We exhibit three different characterizations of the $\infty$-parent SLFV, which are valid in different settings and link together population genetics models and stochastic growth models.
Population protocols are a model of distributed computation intended for the study of networks of independent computing agents with dynamic communication structure. Each agent has a finite number of states, and communication opportunities occur nondeterministically, allowing the agents involved to change their states based on each other's states. Population protocols are often studied in terms of reaching a consensus on whether the input configuration satisfied some predicate. In the present paper we propose an alternative point of view. Instead of studying the properties of inputs that a protocol can recognise, we study the properties of outputs that a protocol eventually ensures. We define constructive expressive power. We show that for general population protocols and immediate observation population protocols the constructive expressive power coincides with the normal expressive power. Immediate observation protocols also preserve their relatively low verification complexity in the constructive expressive power setting.
AbstractThis chapter serves as a summary of the learnings from the present volume and an extension of the scope on disaster-demography nexus. We outline the benefits of exploring the disaster-demography nexus and develop a categorisation summarising seven different approaches to the interlink of disasters with demography from examinations of existing literature. These are: disaster impacts on population, measuring vulnerability, mass displacement, spatial-regional approach, climate change, urbanisation and an applied approach. These seven approaches are our attempt to highlight the complex and multifarious nexus between demography and disasters which may not simply be linked to vulnerability. It is recognised that others may separate or merge some of these approaches in different ways.
In this paper, we review observational aspects of three common small-scale energetic events in the solar transition region (TR), namely: TR explosive events, ultraviolet bursts and jets. These events are defined in either (both) spectral or (and) imaging data. The development of multiple instruments capable of observing the TR has allowed researchers to gain numerous insights into these phenomena in recent years. These events have provided a proxy to study how mass and energy are transported between the solar chromosphere and the corona. As the physical mechanisms responsible for these small-scale events might be similar to the mechanisms responsible for large-scale phenomena, such as flares and coronal mass ejections, analysis of these events could also help our understanding of the solar atmosphere from small to large scales. The observations of these small-scale energetic events demonstrate that the TR is extremely dynamic and is a crucial layer in the solar atmosphere between the chromosphere and the corona.
Interstellar neutral hydrogen (ISN H) gas penetrates freely the heliopause. Inside the inner heliosheath, the charge-exchange interaction of this gas with the shocked solar wind and pickup ions creates energetic neutral atoms (ENAs). ISN H is strongly depleted inside the termination shock but a fraction reaches the Earth's orbit. In these regions of the heliosphere, ISN H is the source population for interstellar pickup ions and for the heliospheric backscatter glow. The Globally Distributed Flux (GDF) of ENAs created in the inner heliosheath has been sampled directly by Interstellar Boundary Explorer (IBEX). Based on these measurements, we calculate the density of the GDF ENA population at the Earth's orbit. We find that this number density is between $10^{-4}$ and $10^{-3}$ cm$^{-3}$, i.e., comparable in magnitude to the number density of ISN H in the downwind portion of the Earth's orbit. Half of this atom population have energies less than $\sim 80$ eV. This GDF population of neutral hydrogen is likely to provide a significant contribution to the intensity of heliospheric glow in the downwind hemisphere, may be the source of the inner source of hydrogen pickup ions, and may be responsible for the excess of production of pickup ions found in the analysis of magnetic wave events induced by the proton pickup process in the downwind region at 1 au from the Sun.
We show that, under mild assumptions, some unimaginable events - which we refer to as Black Swan events - must necessarily occur. It follows as a corollary of our theorem that any computational model of decision-making under uncertainty is incomplete in the sense that not all events that occur can be taken into account. In the context of decision theory we argue that this constitutes a stronger sense of uncertainty than Knightian uncertainty.
The Fisher Ideal index, developed to measure price inflation, is applied to define a population-weighted temperature trend. This method has the advantages that the trend is representative for the population distribution throughout the sample but without conflating the trend in the population distribution and the trend in the temperature. I show that the trend in the global area-weighted average surface air temperature is different in key details from the population-weighted trend. I extend the index to include urbanization and the urban heat island effect. This substantially changes the trend again. I further extend the index to include international migration, but this has a minor impact on the trend.
We present exploratory studies of the underlying event activity and of fragmentation and hadronization of b quarks using $t\overline{t}$ candidate events in proton-proton collision data acquired by the CMS experiment. We reconstruct charm mesons in fully charged decay channels from the reconstructed tracks associated with the hadronization of b quarks from the top decay, and study their kinematics relative to the mother jet. A good agreement is found using MadGraph plus the Pythia 6 Tune Z2* simulation. The effects predicted by alternative settings and generators for the characterization of the underlying event are also explored. These results are expected to contribute in the future to more precise measurements in the top quark sector in particular of the top quark mass by either constraining systematic uncertainties related to the modeling of the underlying event in $t\overline{t}$ events or by paving the way for alternative mass measurement methods.
Girish Kulkarni, Joseph F. Hennawi, Emmanuel Rollinde
et al.
Recent studies have highlighted that galaxies at z = 6-8 fall short of producing enough ionizing photons to reionize the IGM, and suggest that Population III stars could resolve this tension, because their harder spectra can produce ~10x more ionizing photons than Population II. But this argument depends critically on the duration of the Population III era, and because Population III stars form from pristine gas, in turn depends on the rate of galactic enrichment. We use a semi-analytic model of galaxy formation which tracks galactic chemical evolution, to gauge the impact of Population III stars on reionization. Population III SNe produce distinct metal abundances, and we argue that the duration of the Population III era can be constrained by precise relative abundance measurements in high-z damped Lyα absorbers (DLAs), which provide a chemical record of past star-formation. We find that a single generation of Population III stars can self-enrich galaxies above the critical metallicity Zcrit=10^-4 Zsun for the Population III-to-II transition, on a very short timescale of ~10^6 yr, owing to the large metal yields and short lifetimes of Population III stars. This subsequently terminates the Population III era, hence they contribute >~ 50% of the ionizing photons only for z >~ 30, and at z=10 contribute <1%. The Population III contribution can be increased by delaying metal mixing into the ISM. However comparing the resulting metal abundance pattern to existing measurements in z <~ 6 DLAs, we show that the fractional contribution of high-mass Population III stars to the ionization rate must be <~ 10% at z = 10. Future abundance measurements of z~7-8 QSOs and GRBs should probe the era when the chemical vestiges of Population III star formation become detectable.