cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mechanical Hamiltonian systems with respect to linear Poisson structures and Jacobi-Reeb dynamics
Creators: name: Ponte, D. Iglesias
name: Marrero, J. C.
name: Padrón, E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we present a relation between Jacobi-Reeb dynamics and the dynamics associated with a mechanical Hamiltonian system with respect to a linear Poisson structure on a vector bundle. For this purpose, we will use the so-called Jacobi bundle metrics induced by the mechanical Hamiltonian system. These constructions extend classical results on the relation between standard mechanical Hamiltonian systems on cotangent bundles and Reeb dynamics.
description: 18 pages, changed title
Revisiting Kaon Physics in General $Z$ Scenario
Creators: name: Endo, Motoi
name: Kitahara, Teppei
name: Mishima, Satoshi
name: Yamamoto, Kei
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: New physics contributions to the $Z$ penguin are revisited in the light of the recently-reported discrepancy of the direct CP violation in $K\toππ$. Interference effects between the standard model and new physics contributions to $ΔS = 2$ observables are taken into account. Although the effects are overlooked in the literature, they make experimental bounds significantly severer. It is shown that the new physics contributions must be tuned to enhance $\mathcal{B}(K_L \to π^{0} ν\barν)$, if the discrepancy of the direct CP violation is explained with satisfying the experimental constraints. The branching ratio can be as large as $6 \times 10^{-10}$ when the contributions are tuned at the 10 % level.
description: 18 pages, 6 figures; v2: references added, some contributions included in light of gauge invariance; v3: to be published in Phys. Lett. B
Greedy Search for Descriptive Spatial Face Features
Creators: name: Gacav, Caner
name: Benligiray, Burak
name: Topal, Cihan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Facial expression recognition methods use a combination of geometric and appearance-based features. Spatial features are derived from displacements of facial landmarks, and carry geometric information. These features are either selected based on prior knowledge, or dimension-reduced from a large pool. In this study, we produce a large number of potential spatial features using two combinations of facial landmarks. Among these, we search for a descriptive subset of features using sequential forward selection. The chosen feature subset is used to classify facial expressions in the extended Cohn-Kanade dataset (CK+), and delivered 88.7% recognition accuracy without using any appearance-based features.
description: International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2017
An Extensive Data Processing Pipeline for MIMIC-IV
Creators: name: Gupta, Mehak
name: Gallamoza, Brennan
name: Cutrona, Nicolas
name: Dhakal, Pranjal
name: Poulain, Raphael
name: Beheshti, Rahmatollah
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: An increasing amount of research is being devoted to applying machine learning methods to electronic health record (EHR) data for various clinical purposes. This growing area of research has exposed the challenges of the accessibility of EHRs. MIMIC is a popular, public, and free EHR dataset in a raw format that has been used in numerous studies. The absence of standardized pre-processing steps can be, however, a significant barrier to the wider adoption of this rare resource. Additionally, this absence can reduce the reproducibility of the developed tools and limit the ability to compare the results among similar studies. In this work, we provide a greatly customizable pipeline to extract, clean, and pre-process the data available in the fourth version of the MIMIC dataset (MIMIC-IV). The pipeline also presents an end-to-end wizard-like package supporting predictive model creations and evaluations. The pipeline covers a range of clinical prediction tasks which can be broadly classified into four categories - readmission, length of stay, mortality, and phenotype prediction. The tool is publicly available at https://github.com/healthylaife/MIMIC-IV-Data-Pipeline.
Topological Shadowing Methods in Arnold Diffusion: Weak Torsion and Multiple Time Scales
Creators: name: Clarke, Andrew
name: Fejoz, Jacques
name: Guardia, Marcel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37J40

description: Consider a symplectic map which possesses a normally hyperbolic invariant manifold of any even dimension with transverse homoclinic channels. We develop a topological shadowing argument to prove the existence of Arnold diffusion along the invariant manifold, shadowing some iterations of the inner dynamics carried by the invariant manifold and the outer dynamics induced by the stable and unstable foliations. In doing so, we generalise an idea of Gidea and de la Llave in [26], based on the method of correctly aligned windows and a so-called transversality-torsion argument. Our proof permits that the dynamics on the invariant manifold satisfy only a non-uniform twist condition, and, most importantly for applications, that the splitting of separatrices be small in certain directions and thus the associated drift in actions very slow; diffusion occurs in the directions of the manifold having non-small splitting. Furthermore we provide estimates for the diffusion time.
description: 37 pages, 5 figures
Self-testing of binary observables based on commutation
Creators: name: Kaniewski, Jędrzej
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the problem of certifying binary observables based on a Bell inequality violation alone, a task known as self-testing of measurements. We introduce a family of commutation-based measures, which encode all the distinct arrangements of two projective observables on a qubit. These quantities by construction take into account the usual limitations of self-testing and since they are "weighted" by the (reduced) state, they automatically deal with rank-deficient reduced density matrices. We show that these measures can be estimated from the observed Bell violation in several scenarios and the proofs rely only on standard linear algebra. The trade-offs turn out to be tight and, in particular, they give non-trivial statements for arbitrarily small violations. On the other extreme, observing the maximal violation allows us to deduce precisely the form of the observables, which immediately leads to a complete rigidity statement. In particular, we show that for all $n \geq 3$ the $n$-partite Mermin-Ardehali-Belinskii-Klyshko inequality self-tests the $n$-partite Greenberger-Horne-Zeilinger state and maximally incompatible qubit measurements on every party. Our results imply that any pair of projective observables on a qubit can be certified in a truly robust manner. Finally, we show that commutation-based measures give a convenient way of expressing relations among more than two observables.
description: 5 + 4 pages. v2: published version; v3: formatting errors fixed
Forward-fitting STIX visibilities
Creators: name: Volpara, Anna
name: Massa, Paolo
name: Perracchione, Emma
name: Battaglia, Andrea Francesco
name: Garbarino, Sara
name: Benvenuto, Federico
name: Massone, Anna Maria
name: Krucker, Sam
name: Piana, Michele
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 94A08, 65R32

description: Aima. To determine to what extent the problem of forward fitting visibilities measured by the Spectrometer/Telescope Imaging X-rays (STIX) on-board Solar Orbiter is more challenging with respect to the same problem in the case of previous hard X-ray solar imaging missions; to identify an effective optimization scheme for parametric imaging for STIX. Methods. This paper introduces a Particle Swarm Optimization (PSO) algorithm for forward fitting STIX visibilities and compares its effectiveness with respect to the standard simplex-based optimization algorithm used so far for the analysis of visibilities measured by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). This comparison is made by considering experimental visibilities measured by both RHESSI and STIX, and synthetic visibilities generated by accounting for the STIX signal formation model. Results. We found out that the parametric imaging approach based on PSO is as reliable as the one based on the simplex method in the case of RHESSI visibilities. However, PSO is significantly more robust when applied to STIX simulated and experimental visibilities. Conclusions. Standard deterministic optimization is not effective enough for forward-fitting the few visibilities sampled by STIX in the angular frequency plane. Therefore a more sofisticated optimization scheme must be introduced for parametric imaging in the case of the Solar Orbiter X-ray telescope. The forward-fitting routine based on PSO we introduced in this paper proved to be significantly robust and reliable, and could be considered as an effective candidate tool for parametric imaging in the STIX context.
Development of a fast simulator for GEM-based neutron detectors
Creators: name: Santos, R. Felix dos
name: Munhoz, M. G.
name: Moralles, M.
name: Filho, L. A. Serra
name: Bregant, M.
name: Souza, F. A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Gas Electron Multiplier (GEM)-based detectors using a layer of 10B as a neutron converter is becoming popular for thermal neutron detection. A common strategy to simulate this kind of detector is based on two frameworks: Geant4 and Garfield++. The first one provides the simulation of the nuclear interaction between neutrons and the 10B layer, while the second allows the simulation of the interaction of the reaction products with the detector gas leading to the ionization and excitation of the gas molecules. Given the high ionizing power of these nuclear reaction products, a full simulation is very time consuming and must be optimized to become viable. In this work, we present a strategy to develop a fast simulator based on these two frameworks that will allow us to generate enough data for a proper evaluation of the expected performance and optimization of this kind of detector. We will show the first results obtained with this tool concentrating on its validation and performance.
description: Submitted to Journal of Physics: Conference Series. Proceedings of the International Conference on Technology and Instrumentation in Particle Physics (TIPP 2021)
$R_{D^{(*)}}$ anomaly: A possible hint for natural supersymmetry with $R$-parity violation
Creators: name: Altmannshofer, Wolfgang
name: Dev, P. S. Bhupal
name: Soni, Amarjit
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Recently, several $B$-physics experiments have reported an appreciable deviation from the Standard Model (SM) in the tree-level observables $R_{D^{(*)}}$; the combined weighted average now stands at $\approx 4 σ$. We first show the anomaly necessarily implies model-independent collider signals of the form $pp \to b τν$ that should be expediously searched for at ATLAS/CMS as a complementary test of the anomaly. Next we suggest a possible interconnection of the anomaly with the radiative stability of the Standard Model Higgs boson and point to a minimal effective supersymmetric scenario with $R$-parity violation as the underlying cause. We also comment on the possibility of simultaneously explaining the recently reported $R_{K^{(*)}}$ anomaly in this setup.
description: 11 pages, 4 figures; version accepted for publication in PRD
Hyperaccurate bounds in discrete-state Markovian systems
Creators: name: Busiello, Daniel Maria
name: Fiore, Carlos
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Generalized empirical currents represent a vast class of thermodynamic observables of mesoscopic systems. Their fluctuations satisfy the thermodynamic uncertainty relations (TURs), as they can be bounded by the average entropy production. Here, we derive a general closed expression for the hyperaccurate current in discrete-state Markovian systems, i.e., the one with the least fluctuations, for both discrete- and continuous-time evolution. We show that its associated hyperaccurate bound is generally much tighter than the one given by the TURs, and might be crucial to providing a reliable estimation of the average entropy production. We also show that one-loop systems (rings) exhibit a hyperaccurate current only for finite times, highlighting the importance of short-time observations. Additionally, we derive two novel bounds for the efficiency of work-to-work converters, solely as a function of either the input or the output power. Finally, our theoretical results are employed to analyze a 6-state model network for kinesin, and a chemical system in a thermal gradient exhibiting a dissipation-driven selection of states.
The Transformation of the Superconducting Gap to an Insulating Pseudogap at a Critical Hole Density in the Cuprates
Creators: name: Liu, Ye-Hua
name: Wang, Wan-Sheng
name: Wang, Qiang-Hua
name: Zhang, Fu-Chun
name: Rice, T. M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We apply the recent wavepacket formalism developed by Ossadnik to describe the origin of the short range ordered pseudogap state as the hole doping is lowered through a critical density in cuprates. We argue that the energy gain that drives this precursor state to Mott localization, follows from maximizing umklapp scattering near the Fermi energy. To this end we show how energy gaps driven by umklapp scattering can open on an appropriately chosen surface, as proposed earlier by Yang, Rice and Zhang. The key feature is that the pairing instability includes umklapp scattering, leading to an energy gap not only in the single particle spectrum but also in the pair spectrum. As a result the superconducting gap at overdoping is turned into an insulating pseudogap, in the antinodal parts of the Fermi surface.
description: with new introduction
Bioplausible multiscale filtering in retino-cortical processing as a mechanism in perceptual grouping
Creators: name: Nematzadeh, Nasim
name: Powers, David M. W.
name: Lewis, Trent W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Why does our visual system fail to reconstruct reality, when we look at certain patterns? Where do Geometrical illusions start to emerge in the visual pathway? How far should we take computational models of vision with the same visual ability to detect illusions as we do? This study addresses these questions, by focusing on a specific underlying neural mechanism involved in our visual experiences that affects our final perception. Among many types of visual illusion, Geometrical and, in particular, Tilt Illusions are rather important, being characterized by misperception of geometric patterns involving lines and tiles in combination with contrasting orientation, size or position. Over the last decade, many new neurophysiological experiments have led to new insights as to how, when and where retinal processing takes place, and the encoding nature of the retinal representation that is sent to the cortex for further processing. Based on these neurobiological discoveries, we provide computer simulation evidence from modelling retinal ganglion cells responses to some complex Tilt Illusions, suggesting that the emergence of tilt in these illusions is partially related to the interaction of multiscale visual processing performed in the retina. The output of our low-level filtering model is presented for several types of Tilt Illusion, predicting that the final tilt percept arises from multiple-scale processing of the Differences of Gaussians and the perceptual interaction of foreground and background elements. Our results suggest that this model has a high potential in revealing the underlying mechanism connecting low-level filtering approaches to mid- and high-level explanations such as Anchoring theory and Perceptual grouping.
description: 23 pages, 8 figures, Brain Informatics journal: Full text access: https://link.springer.com/article/10.1007/s40708-017-0072-8
Conformal embeddings via heat kernel
Creators: name: Su, Zhitong
Publisher: name: No Publisher Supplied
Year: 2022

description: Embedding theorems play a fundamental role in differential geometry, some of the theorems use extrinsic information to construct the embedding, while some solely use intrinsic one, hence are canonical. In this thesis, for any n-dimensional compact Riemannian Manifold M with smooth metric g, by using the heat kernel embedding, we construct a canonical family of conformal embeddings C_{t,k}: M--->R^{q(t)}, with t>0 sufficiently small, q(t)>> t^{-n/2}, and k as a function of O(t^l) in proper sense. The canonical property of the embeddings is preserved by finding all the conformal ones, which are the major differences from the isometric case.
Improved stellar limits on a light CP-even scalar
Creators: name: Balaji, Shyam
name: Dev, P. S. Bhupal
name: Silk, Joseph
name: Zhang, Yongchao
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We derive improved stellar luminosity limits on a generic light CP-even scalar field $S$ mixing with the Standard Model (SM) Higgs boson from the supernova SN1987A, the Sun, red giants (RGs) and white dwarfs (WDs). For the first time, we include the geometric effects for the decay and absorption of $S$ particles in the stellar interior. For SN1987A and the Sun, we also take into account the detailed stellar profiles. We find that a broad range of the scalar mass and mixing angle can be excluded by our updated astrophysical constraints. For instance, SN1987A excludes $1.0\times10^{-7} \lesssim \sinθ\lesssim 3.0\times 10^{-5}$ and scalar mass up to 219 MeV, which covers the cosmological blind spot with a high reheating temperature. The updated solar limit excludes the mixing angle in the range of $1.5\times 10^{-12} < \sinθ< 1$, with scalar mass up to 45 keV. The RG and WD limits are updated to $5.3\times 10^{-13} < \sin θ< 0.39$ and $2.8\times 10^{-18} < \sin θ< 1.8\times 10^{-4}$, with scalar mass up to 392 keV and 290 keV, respectively.
description: 31 pages, 11 figures, 2 tables, calculations updated, more references
On finite symmetries and their gauging in two dimensions
Creators: name: Bhardwaj, Lakshya
name: Tachikawa, Yuji
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Category Theory (math.CT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: It is well-known that if we gauge a $\mathbb{Z}_n$ symmetry in two dimensions, a dual $\mathbb{Z}_n$ symmetry appears, such that re-gauging this dual $\mathbb{Z}_n$ symmetry leads back to the original theory. We describe how this can be generalized to non-Abelian groups, by enlarging the concept of symmetries from those defined by groups to those defined by unitary fusion categories. We will see that this generalization is also useful when studying what happens when a non-anomalous subgroup of an anomalous finite group is gauged: for example, the gauged theory can have non-Abelian group symmetry even when the original symmetry is an Abelian group. We then discuss the axiomatization of two-dimensional topological quantum field theories whose symmetry is given by a category. We see explicitly that the gauged version is a topological quantum field theory with a new symmetry given by a dual category.
description: 73 pages, v2: correct treatment of pivotal structure leading to the resolution of a contradiction between non-trivial anomaly and unitarity
Strongly-overdoped La$_{2-x}$Sr$_x$CuO$_4$: Evidence for Josephson-coupled grains of strongly-correlated superconductor
Creators: name: Li, Yangmu
name: Sapkota, A.
name: Lozano, P. M.
name: Du, Zengyi
name: Li, Hui
name: Wu, Zebin
name: Kundu, Asish K.
name: Koch, R. J.
name: Wu, Lijun
name: Winn, B. L.
name: Chi, Songxue
name: Matsuda, M.
name: Frontzek, M.
name: Bozin, E. S.
name: Zhu, Yimei
name: Bozovic, I.
name: Pasupathy, Abhay N.
name: Drozdov, Ilya K.
name: Fujita, Kazuhiro
name: Gu, G. D.
name: Zaliznyak, Igor
name: Li, Qiang
name: Tranquada, J. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we present an experimental study of single-crystal and thin film samples of La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) with $x\ge0.25$. In particular, measurements of bulk susceptibility on LSCO crystals with $x=0.25$ indicate an onset of diamagnetism at $T_{c1}=38.5$ K, with a sharp transition to a phase with full bulk shielding at $T_{c2}=18$ K, independent of field direction. Strikingly, the in-plane resistivity only goes to zero at $T_{c2}$. Inelastic neutron scattering on $x=0.25$ crystals confirms the presence of low-energy incommensurate magnetic excitations with reduced strength compared to lower doping levels. The ratio of the spin gap to $T_{c2}$ is anomalously large. Our results are consistent with a theoretical prediction for strongly overdoped cuprates by Spivak, Oreto, and Kivelson, in which superconductivity initially develops within disconnected self-organized grains characterized by a reduced hole concentration, with bulk superconductivity occurring only after superconductivity is induced by proximity effect in the surrounding medium of higher hole concentration. Beyond the superconducting-to-metal transition, local differential conductance measurements on an LSCO thin film suggest that regions with pairing correlations survive, but are too dilute to support superconducting order. Future experiments will be needed to test the degree to which these results apply to overdoped cuprates in general.
description: 21 pages, 15 figures; added more sample characterizations, results for another sample, more discussion; accepted version
Putting the micro into the macro: A molecularly-augmented hydrodynamic model of dynamic wetting applied to flow instabilities during forced dewetting
Creators: name: Keeler, Jack S.
name: Blake, Terence D.
name: Lockerby, Duncan A.
name: Sprittles, James E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We report a molecularly-augmented continuum-based computational model of dynamic wetting and apply it to the displacement of an externally-driven liquid plug between two partially-wetted parallel plates. The results closely follow those obtained in a recent molecular-dynamics (MD) study of the same problem Toledano (2021) which we use as a benchmark. We are able to interpret the maximum speed of dewetting $U^*_{\mathrm{crit}}$ as a fold bifurcation in the steady phase diagram and show that its dependence on the true contact angle $θ_{\mathrm{cl}}$ is quantitatively similar to that found using MD. A key feature of the model is that the contact angle is dependent on the speed of the contact line, with $θ_{\mathrm{cl}}$ emerging as part of the solution. The model enables us to study the formation of a thin film at dewetting speeds $U^*>U^*_{\mathrm{crit}}$ across a range of length scales, including those that are computationally prohibitive to MD simulations. We show that the thickness of the film scales linearly with the channel width and is only weakly dependent on the capillary number. This work provides a link between matched asymptotic techniques (valid for larger geometries) and MD simulations (valid for smaller geometries). In addition, we find that the apparent angle, the experimentally visible contact angle at the fold bifurcation, is not zero. This is in contrast to the prediction of conventional treatments based on the lubrication model of flow near the contact line, but consistent with experiment.
description: 22 pages
Evidence of electronic phase separation in the strongly correlated semiconductor YbB12
Creators: name: Azarevich, A.
name: Bolotina, N.
name: Khrykina, O.
name: Bogach, A.
name: Zhukova, E.
name: Gorshunov, B.
name: Melentev, A.
name: Bedran, Z.
name: Alyabyeva, A.
name: Belyanchikov, M.
name: Voronov, V.
name: Sluchanko, N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The studies of high-quality single-domain crystals of YbB12 were carried out by the precise x-ray diffraction technique in combination with the low temperature polarized THz - infrared spectroscopy and accurate magnetotransport measurements. It has been shown for the first time that this archetypal strongly correlated system with a metal-insulator transition to a mysterious dielectric ground state with a metal Fermi surface (Science 362, 65-69 (2018) and ibid 362, 32-33 (2018)) is actually a heterogeneous compound in the regime of electronic phase separation. Changes in the configuration of the discovered dynamic charge stripes are investigated upon cooling, as a result, a conclusion is drawn in favor of a crossover between different patterns of the filamentary electronic structure penetrating the semiconducting matrix of YbB12. We argue that the discovery of stripes in YbB12 is fundamental, elucidating the nature of exotic dielectric state in Kondo insulators.
description: 12 pages including 4 figures
Classification and mapping of low-statured 'shrubland' cover types in post-agricultural landscapes of the US Northeast
Creators: name: Mahoney, Michael J
name: Johnson, Lucas K
name: Guinan, Abigail Z
name: Beier, Colin M
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Novel plant communities reshape landscapes and pose challenges for land cover classification and mapping that can constrain research and stewardship efforts. In the US Northeast, emergence of low-statured woody vegetation, or shrublands, instead of secondary forests in post-agricultural landscapes is well-documented by field studies, but poorly understood from a landscape perspective, which limits the ability to systematically study and manage these lands. To address gaps in classification/mapping of low-statured cover types where they have been historically rare, we developed models to predict shrubland distributions at 30m resolution across New York State (NYS), using a stacked ensemble combining a random forest, gradient boosting machine, and artificial neural network to integrate remote sensing of structural (airborne LIDAR) and optical (satellite imagery) properties of vegetation cover. We first classified a 1m canopy height model (CHM), derived from a patchwork of available LIDAR coverages, to define shrubland presence/absence. Next, these non-contiguous maps were used to train a model ensemble based on temporally-segmented imagery to predict shrubland probability for the entire study landscape (NYS). Approximately 2.5% of the CHM coverage area was classified as shrubland. Models using Landsat predictors trained on the classified CHM were effective at identifying shrubland (test set AUC=0.893, real-world AUC=0.904), in discriminating between shrub/young forest and other cover classes, and produced qualitatively sensible maps, even when extending beyond the original training data. Our results suggest that incorporation of airborne LiDAR, even from a discontinuous patchwork of coverages, can improve land cover classification of historically rare but increasingly prevalent shrubland habitats across broader areas.
description: 43 pages (35 main text, 8 supplementary materials); 11 figures (10 main text, 1 supplementary materials), 10 tables (4 main text, 6 supplementary materials)
Metastability in a Stochastic System of Spiking Neurons with Leakage
Creators: name: Laxa, Kádmo de S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60K35, 60G55, 82C22

description: We consider a finite system of interacting point processes with memory of variable length modeling a finite but large network of spiking neurons with two different leakage mechanisms. Associated to each neuron there are two point processes, describing its successive spiking and leakage times. For each neuron, the rate of the spiking point process is an exponential function of its membrane potential, with the restriction that the rate takes the value 0 when the membrane potential is 0. At each spiking time, the membrane potential of the neuron resets to 0, and simultaneously, the membrane potentials of the other neurons increase by one unit. The leakage can be modeled in two different ways. In the first way, at each occurrence time of the leakage point process associated to a neuron, the membrane potential of that neuron is reset to 0, with no effect on the other neurons. In the second way, if the membrane potential of the neuron is strictly positive, at each occurrence time of the leakage point process associated to that neuron, its membrane potential decreases by one unit, with no effect on the other neurons. In both cases, the leakage point process of the neurons has constant rate. For both models, we prove that the system has a metastable behavior as the population size diverges. This means that the time at which the system gets trapped by the list of null membrane potentials suitably re-scaled converges to a mean one exponential random time.
Where Neutrino Decoherence Lies
Creators: name: Ciuffoli, Emilio
name: Evslin, Jarah
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recently, several studies of neutrino oscillations in the vacuum have not found the decoherence long expected from the separation of wave packets of neutrinos in different mass eigenstates. We show that such decoherence will, on the other hand, be present in a treatment including any mechanism which leads to a dependence of the final state on both the neutrino's emission and absorption time. Our demonstration is in the 3+1d $V-A$ model, however the details of this model lead to an overall factor which does not affect our conclusions. This allows us to consider a simpler model. There we show that if the positions of the final state particles are measured, or equivalently entangled with the environment, then decoherence will damp neutrino oscillations. We also show that wave packet spreading can cause the decoherence to eventually saturate, without completely suppressing the oscillations.
description: 28 pages, 2 figures
An Incentive-Based Online Optimization Framework for Distribution Grids
Creators: name: Zhou, Xinyang
name: Dall'Anese, Emiliano
name: Chen, Lijun
name: Simonetto, Andrea
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper formulates a time-varying social-welfare maximization problem for distribution grids with distributed energy resources (DERs) and develops online distributed algorithms to identify (and track) its solutions. In the considered setting, network operator and DER-owners pursue given operational and economic objectives, while concurrently ensuring that voltages are within prescribed limits. The proposed algorithm affords an online implementation to enable tracking of the solutions in the presence of time-varying operational conditions and changing optimization objectives. It involves a strategy where the network operator collects voltage measurements throughout the feeder to build incentive signals for the DER-owners in real time; DERs then adjust the generated/consumed powers in order to avoid the violation of the voltage constraints while maximizing given objectives. The stability of the proposed schemes is analytically established and numerically corroborated.
Reflected Entropy in AdS$_3$/WCFT
Creators: name: Chen, Bin
name: Liu, Yuefeng
name: Yu, Boyang
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Reflected entropy is a newly proposed notion in quantum information. It has important implications in holography. In this work, we study the reflected entropy in the framework of the AdS$_3$/WCFT correspondence. We determine the scaling dimensions and charges of various twist operators in non-Abelian orbifold WCFT by generalizing the uniformization map and taking into account of the charge conservation. This allows us to compute the reflected entropy, logarithmic negativity and odd entropy for two disjoint intervals in holographic WCFT. We find that the reflected entropy can be related holographically to the pre-entanglement wedge cross-section, which is given by the minimal distance between the benches in two swing surfaces.
description: 52 pages, 11 figures
New constraint on the tensor-to-scalar ratio from the $Planck$ and BICEP/Keck Array data using the profile likelihood
Creators: name: Campeti, Paolo
name: Komatsu, Eiichiro
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We derive a new upper bound on the tensor-to-scalar ratio parameter $r$ using the frequentist profile likelihood method. We vary all the relevant cosmological parameters of the $Λ$CDM model, as well as the nuisance parameters. Unlike the Bayesian analysis using Markov Chain Monte Carlo (MCMC), our analysis is independent of the choice of priors. Using $Planck$ Public Release 4, BICEP/Keck Array 2018, $Planck$ CMB lensing, and BAO data, we find an upper limit of $r<0.037$ at 95% C.L., similar to the Bayesian MCMC result of $r<0.038$ for a flat prior on $r$ and a conditioned $Planck$ lowlEB covariance matrix.
description: 7 pages, 2 Figures, 2 Tables. Submitted to MNRAS. Updated references
Near-monochromatic tuneable cryogenic niobium electron field emitter
Creators: name: Johnson, Cameron W.
name: Schmid, Andreas K.
name: Mankos, Marian
name: Röpke, Robin
name: Kerker, Nicole
name: Wong, Ed K.
name: Ogletree, D. Frank
name: Minor, Andrew M.
name: Stibor, Alexander
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applied Physics (physics.app-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Creating, manipulating, and detecting coherent electrons is at the heart of future quantum microscopy and spectroscopy technologies. Leveraging and specifically altering the quantum features of an electron beam source at low temperatures can enhance its emission properties. Here, we describe electron field emission from a monocrystalline, superconducting niobium nanotip at a temperature of 5.9 K. The emitted electron energy spectrum reveals an ultra-narrow distribution down to 16 meV due to tunable resonant tunneling field emission via localized band states at a nano-protrusion's apex and a cut-off at the sharp low-temperature Fermi-edge. This is an order of magnitude lower than for conventional field emission electron sources. The self-focusing geometry of the tip leads to emission in an angle of 3.7 deg, a reduced brightness of 3.8 x 10exp8 A/(m2 sr V), and a stability of hours at 4.1 nA beam current and 69 meV energy width. This source will decrease the impact of lens aberration and enable new modes in low-energy electron microscopy, electron energy loss spectroscopy, and high-resolution vibrational spectroscopy.
description: to be published in Phys. Rev. Lett. (2022)
Query Complexity Based Optimal Processing of Raw Data
Creators: name: Patel, Mayank
name: Bhise, Minal
Publisher: name: arXiv
Year: 2022
Subjects: subject: Databases (cs.DB)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: The paper aims to find an efficient way for processing large datasets having different types of workload queries with minimal replication. The work first identifies the complexity of queries best suited for the given data processing tool . The paper proposes Query Complexity Aware partitioning technique QCA with a lightweight query identification and partitioning algorithm. Different replication approaches have been studied to cover more use-cases for different application workloads. The technique is demonstrated using a scientific dataset known as Sloan Digital Sky Survey SDSS. The results show workload execution time WET reduced by 94.6% using only 6.7% of the dataset in loaded format compared to the original dataset. The QCA technique also reduced multi-node replication by 5.8x times compared to state-of-the-art workload aware WA techniques. The multi-node and multi-core execution of workload using QCA proposed partitions reduced WET by 42.66% and 25.46% compared to WA.
description: Accepted in 10th Region 10 Humanitarian Technology Conference (R10-HTC)
OS FUNDAMENTOS DO ENSINO DE FILOSOFIA NOS LIVROS DIDÁTICOS APROVADOS PELO PNLD 2018
Creators: name: Tavares de Almeida, Adriana
name: Alice Corrêa de Araújo, Maria
name: Guimarães de Araújo, Nilton
name: Limeira da Silva, Paulo
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 390102
subject: Curriculum and pedagogy theory and development

description: Em 2018, no Brasil, um, entre os oito livros didáticos de Filosofia aprovados pelo PNLD (Programa Nacional do Livro Didático) foi distribuído gratuitamente nas escolas públicas de ensino aos matriculados no ensino médio – para cada escola, uma escolha. No ano anterior, em 2017, pudemos, como professores, realizar a escolha do livro que seria adotado na escola em que trabalhamos. Resolvemos, então, transformar nossa análise do “Manual do Professor” das oito obras aprovadas pelo PNLD nesta publicação. Tivemos como objetivo geral identificar os fundamentos do ensino de Filosofia em nível médio apresentados nos suplementos dos manuais do professor dirigidos aos docentes. Mais especificamente: descrever concepções apresentadas sobre o que é Filosofia; localizar fundamentos de ensino e aprendizagem de Filosofia; relatar argumentos sobre a importância do ensino de Filosofia. Entre as ideias mais comuns que fundamentam o ensino de Filosofia, estão: destaque à importância e relação necessária entre filosofar e Filosofia; defesa da importância da Filosofia enquanto legado do passado; reconhecimento de Filosofias e não uma Filosofia; referência às competências específicas da Filosofia evidenciadas nos Parâmetros Curriculares Nacionais
General Relativistic Dynamics of an Extreme Mass-Ratio Binary interacting with an External Body
Creators: name: Yang, Huan
name: Casals, Marc
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We study the dynamics of a hierarchical three-body system in the general-relativistic regime: an extreme mass-ratio inner binary under the tidal influence of an external body. The inner binary consists of a central Schwarzschild black hole and a compact test body moving around it (outer binary). We discover three types of tidal effects on the orbit of the test body. First, the angular moment of the inner binary precesses around the angular momentum of the outer binary. Second, the tidal field drives a "transient resonance" when the radial and azimuthal frequencies are commensurate with each other. In contrast with resonances driven by the gravitational self-force, this tidal-driven resonance may boost the orbital angular momentum. Finally, as an orbit-dynamical effect during the non-resonant phase, we calculate the correction to the Innermost Stable Circular (mean) Orbit (ISCO) due to the tidal interaction. Hierarchical three-body systems are potential sources for future space-based gravitational wave missions and the tidal effects that we find could contribute significantly to their waveform.
description: 12 pages, 3 figures, published version
From Rotating to Charged Black Holes and Back Again
Creators: name: Aalsma, Lars
name: Shiu, Gary
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The mild form of the Weak Gravity Conjecture (WGC) requires higher derivative corrections to extremal charged black holes to increase their charge-to-mass ratio. This allows decay via emission of a smaller extremal black hole. In this paper, we investigate if similar constraints hold for extremal rotating black holes. We do so by considering the leading higher derivative corrections to the four-dimensional Kerr black hole and five-dimensional Myers-Perry black hole. We use a known mapping of these rotating solutions to a four-dimensional non-rotating dyonic Kaluza-Klein black hole and impose the WGC on this charged solution. Going back again to the rotating solutions, this fixes the sign of the corrections to the rotating extremality bounds. The sign of the corrections is non-universal, depending on the black hole under consideration. We argue that this is not at odds with black hole decay, because of the presence of a superradiant instability that persists in the extremal limit. When this instability is present, the WGC is implied for the four-dimensional charged black hole.
description: 17+2 pages
Stochastic resetting in a nonequilibrium environment
Creators: name: Goswami, Koushik
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: This study examines the dynamics of a tracer particle diffusing in a nonequilibrium medium under stochastic resetting. The nonequilibrium state is induced by harmonic coupling between the tracer and bath particles, generating memory effects with exponential decay in time. We explore the tracer's behavior under a Poissonian resetting protocol, where resetting does not disturb the bath environment, with a focus on key dynamical behavior and first-passage properties, both in the presence and absence of an external force. The interplay between coupling strength and diffusivity of bath particle significantly impacts both the tracer's relaxation dynamics and search time, with external forces further modulating these effects. Our analysis identifies distinct hot and cold bath particles based on their diffusivities, revealing that coupling to a hot particle facilitates the searching process, whereas coupling to a cold particle hinders it. Using a combination of numerical simulations and analytical methods, this study provides a comprehensive framework for understanding resetting mechanisms in non-Markovian systems, with potential applications to complex environments such as active and viscoelastic media, where memory-driven dynamics and nonequilibrium interactions are significant.
Exploring the structure-property relations of thin-walled, 2D extruded lattices using neural networks
Creators: name: He, Junyan
name: Kushwaha, Shashank
name: Abueidda, Diab
name: Jasiuk, Iwona
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: This paper investigates the structure-property relations of thin-walled lattices under dynamic longitudinal compression, characterized by their cross-sections and heights. These relations elucidate the interactions of different geometric features of a design on mechanical response, including energy absorption. We proposed a combinatorial, key-based design system to generate different lattice designs and used the finite element method to simulate their response with the Johnson-Cook material model. Using an autoencoder, we encoded the cross-sectional images of the lattices into latent design feature vectors, which were supplied to the neural network model to generate predictions. The trained models can accurately predict lattice energy absorption curves in the key-based design system and can be extended to new designs outside of the system via transfer learning.
Long-Lived Non-Equilibrium Interstitial-Solid-Solutions in Binary Mixtures
Creators: name: de Anda, I. Ríos
name: Turci, F.
name: Sear, R.
name: Royall, C. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We perform particle resolved experimental studies on the heterogeneous crystallisation process of two compo- nent mixtures of hard spheres. The components have a size ratio of 0.39. We compared these with molecular dynamics simulations of homogenous nucleation. We find for both experiments and simulations that the final assemblies are interstitial solid solutions, where the large particles form crystalline close-packed lattices, whereas the small particles occupy random interstitial sites. This interstitial solution resembles that found at equilibrium when the size ratios are 0.3 [Filion et al., Phys. Rev. Lett. 107, 168302 (2011)] and 0.4 [Filion, PhD Thesis, Utrecht University (2011)]. However, unlike these previous studies, for our system sim- ulations showed that the small particles are trapped in the octahedral holes of the ordered structure formed by the large particles, leading to long-lived non-equilibrium structures in the time scales studied and not the equilibrium interstitial solutions found earlier. Interestingly, the percentage of small particles in the crystal formed by the large ones rapidly reaches a maximum of around 14% for most of the packing fractions tested, unlike previous predictions where the occupancy of the interstitial sites increases with the system concentration. Finally, no further hopping of the small particles was observed.
Egocentric Hierarchical Visual Semantics
Creators: name: Erculiani, Luca
name: Bontempelli, Andrea
name: Passerini, Andrea
name: Giunchiglia, Fausto
Publisher: name: Zenodo
Year: 2023
Subjects: artificial intelligence
visual semantics
interactive machine learning

description: Presentation of the conference paper titled "Egocentric Hierarchical Visual Semantics" accepted at The second International Conference on Hybrid Human-Artificial Intelligence (HHAI 2023).