cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Reciprocal Heuristic Model for Diffuse Scattering from Walls and Surfaces
Creators: name: Vitucci, Enrico M.
name: Cenni, Nicolò
name: Fuschini, Franco
name: Degli-Esposti, Vittorio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: Classical Physics (physics.class-ph)
subject: Optics (physics.optics)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences

description: Diffuse scattering of electromagnetic waves from natural and artificial surfaces has been extensively studied in various disciplines, including radio wave propagation, and several diffuse scattering models based on different approaches have been proposed over the years, two of the most popular ones being Kirchhoff Theory and the so-called Effective Roughness heuristic model. The latter, although less rigorous than the former, is more flexible and applicable to a wider range of real-world cases, including non-Gaussian surfaces, surfaces with electrically small correlation lengths and scattering from material inhomogeneities that are often present under the surface. Unfortunately, the Effective Roughness model, with the exception of its Lambertian version, does not satisfy reciprocity, which is an important physical-soundness requirement for any propagation model. In the present work, without compromising its effectiveness and its simple and yet sound power-balance approach, we propose a reciprocal version of the Effective Roughness model, which can be easily implemented and replaced to the old version in ray-based propagation models. The new model is analyzed and compared to the old one and to other popular models. Once properly calibrated, it is shown to yield similar - if not better - performance with respect to the old one when checked vs. measurements.
Solving the thoracic inverse problem in the fruit fly
Creators: name: Pons, Arion
name: Perl, Illy
name: Ben-Dov, Omri
name: Maya, Roni
name: Beatus, Tsevi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: In many insect species, the thoracic structure plays a crucial role in enabling flight. In the dipteran indirect flight mechanism, the thorax acts as a transmission link between the flight muscles and the wings, and it is often thought to act as an elastic modulator: improving flight motor efficiency thorough linear or nonlinear resonance. But as peering closely into the drivetrain of tiny insects is experimentally difficult, the nature of this elastic modulation, and any associated resonant effects, are unclear. Here, we present a new inverse-problem methodology to surmount this difficulty. In a data synthesis process, we integrate experimentally-observable aerodynamic and musculoskeletal data for the fruit fly D. melanogaster, and identify several surprising properties of the fly's thorax. We find that fruit flies have an energetic need for flight motor resonance: energy savings due to flight motor elasticity can be up be to 30%. However, the elasticity of the flight muscles themselves is sufficient - and sometimes more than sufficient - to ensure flight motor resonance. In fruit flies, the role of the thorax as an elastic modulator is likely to be insignificant. We discover also a fundamental link between the fruit fly wingbeat kinematics and musculature dynamics: wingbeat kinematics show key adaptions, including in wing elevation angle, that ensure that wingbeat load requirements match musculature load output capability. Together, these newly-identified properties lead to novel conceptual model of the fruit fly's flight motor: a strongly-nonlinear structure, resonant due to muscular elasticity, and intensely concerned with ensuring that the primary flight muscles are operating efficiently. Our inverse-problem methodology sheds new light on the complex behavior of these tiny flight motors, and provides avenues for further studies in a range of other insects.
Multiphase ISM in low luminosity radio galaxies: A case study of NGC 708
Creators: name: Sahu, Sheetal K
name: Pandey, S K
name: Chaware, L
name: Pandge, M B
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a multi-wavelength study of a nearby radio loud elliptical galaxy NGC708, selected from the Bologna B2 sample of radio galaxies. We obtained optical broad band and narrow images from IGO 2m telescope (Pune, India). We supplement the multi-wavelength coverage of the observation by using X-ray data from Chandra, infrared data from 2MASS, Spitzer and WISE and optical image from DSS and HST. In order to investigate properties of interstellar medium, we have generated unsharp-masked, color, residual, quotient, dust extinction, H_alph emission maps. From the derived maps it is evident that cool gas, dust, warm ionized H_alpha and hot X-ray gas are spatially associated with each other. We investigate the inner and outer photometric and kinematic properties of the galaxy using surface brightness profiles. From X-ray 2d beta model, unsharp masking, surface brightness profiles techniques, it is evident that pair of X-ray cavities are present in this system and which are ~5.6 Kpc away from the central X-ray source.
description: 2 Pages, 1 Figure, 1 Table. From interstellar clouds to star-forming galaxies: universal Processes:Proceedings IAU Symposium No. 315, 2015
Bottom hadro-chemistry in high-energy hadronic collisions
Creators: name: He, Min
name: Rapp, Ralf
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The hadro-chemistry of bottom quarks ($b$) produced in hadronic collisions encodes valuable information on the mechanism of color-neutralization in these reactions. Since the $b$-quark mass is much larger than the typical hadronic scale of $\sim$1\,GeV, $b\bar b$ pair production is expected to be well separated from subsequent hadronization processes. A significantly larger fraction of $b$ baryons has been observed in proton-proton ($pp$) and proton-antiproton ($p\bar{p}$) reactions relative to $e^+e^-$ collisions, challenging theoretical descriptions. We address this problem by employing a statistical hadronization approach with an augmented set of $b$-hadron states beyond currently measured ones, guided by the relativistic quark model and lattice-QCD computations. Assuming {\it relative} chemical equilibrium between different $b$-hadron yields, thermal densities are used as fragmentation weights of $b$-quarks into various hadron species. With quark model estimates of the decay patterns of excited states, the fragmentation fractions of weakly-decaying $b$ hadrons are computed and found to agree with measurements in $p\bar{p}$ collisions at the Tevatron. By combining transverse-momentum ($p_T$) distributions of $b$-quarks from perturbative QCD with thermal weights and independent fragmentation toward high $p_T$, a fair description of the $p_T$-dependent $\bar{B}_s^0/B^-$ and $Λ_b^0/B^-$ ratios measured in $pp$ collisions at the LHC is obtained. Finally, we implement the hadro-chemistry into a strongly-coupled transport approach for $b$-quarks in heavy-ion collisions, utilizing previously determined $b$-quark transport coefficients in the Quark-Gluon Plasma, to highlight the modifications of hadro-chemistry and collective behavior of $b$ hadrons in Pb-Pb collisions at the LHC.
description: 6 pages, 4 figures
Bird detection in audio: a survey and a challenge
Creators: name: Stowell, Dan
name: Wood, Mike
name: Stylianou, Yannis
name: Glotin, Hervé
Publisher: name: arXiv
Year: 2016
Subjects: subject: Sound (cs.SD)
subject: FOS: Computer and information sciences

description: Many biological monitoring projects rely on acoustic detection of birds. Despite increasingly large datasets, this detection is often manual or semi-automatic, requiring manual tuning/postprocessing. We review the state of the art in automatic bird sound detection, and identify a widespread need for tuning-free and species-agnostic approaches. We introduce new datasets and an IEEE research challenge to address this need, to make possible the development of fully automatic algorithms for bird sound detection.
description: Slightly extended preprint of paper accepted for MLSP 2016
Characterization of functions with zero traces via the distance function and Lorentz spaces
Creators: name: Nekvinda, Aleš
name: Turčinová, Hana
Publisher: name: arXiv
Year: 2022
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46E35, 46E30

description: Consider a regular domain $Ω\subset \mathbb{R}^N$ and let $d(x)=\operatorname{dist}(x,\partialΩ)$. Denote $L^{1,\infty}_a(Ω)$ the space of functions from $L^{1,\infty}(Ω)$ having absolutely continuous quasinorms. This set is essentially smaller than $L^{1,\infty}(Ω)$ but, at the same time, essentially larger than a union of all $L^{1,q}(Ω)$, $q\in[1,\infty)$. A classical result of late 1980's states that for $p\in (1,\infty)$ and $m \in \mathbb{N}$, $u$ belongs to the Sobolev space $W^{m,p}_0(Ω)$ if and only if $u/d^m\in L^p(Ω)$ and $\left|\nabla^m u\right|\in L^p(Ω)$. During the consequent decades, several authors have spent considerable effort in order to relax the characterizing condition. Recently, it was proved that $u\in W^{m,p}_0(Ω)$ if and only if $u/d^m\in L^1(Ω)$ and $\left|\nabla^m u\right|\in L^p(Ω)$. In this paper we show that for $N\geq1$ and $p\in(1,\infty)$ we have $u\in W^{1,p}_0(Ω)$ if and only if $u/d\in L^{1,\infty}_a(Ω)$ and $\left|\nabla u\right|\in L^p(Ω)$. Moreover, we present a counterexample which demonstrates that after relaxing the condition $u/d\in L^{1,\infty}_a(Ω)$ to $u/d\in L^{1,\infty}(Ω)$ the equivalence no longer holds.
description: 25 pages, 4 figures
Instagram and the Art of Curation
Creators: Courtney Marion Wagner
Publisher: name: University of Alberta Library
Year: 2022

Purpose: To examine the role that reflective, conscious curation of body-image-related Instagram

content has on users and the suitability of participant diaries in collecting this information.

Methods: Three female Instagram users took part in a qualitative phenomenological study where

they completed participant diaries on curating the content of their personal Instagram accounts.

A debrief interview took place after the journaling concluded. Data was then separated into

significant statements and coded into themes.

Findings: Data presented in this study demonstrates the benefits of this practice experienced by

the participants indicating that this is a useful skill for social media users to be aware of and

develop as it can have a real-world impact. However, participants are limited by the structural

restrictions of Instagram itself.

Conclusion: While Instagram’s structural limitations impact individual content curation, it was

found that users were also applying the skill to areas beyond body image-related content.

Findings may also be applied to future digital literacy strategies and initiatives.
Mapping Exoplanets
Creators: name: Cowan, Nicolas B.
name: Fujii, Yuka
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The varied surfaces and atmospheres of planets make them interesting places to live, explore, and study from afar. Unfortunately, the great distance to exoplanets makes it impossible to resolve their disk with current or near-term technology. It is still possible, however, to deduce spatial inhomogeneities in exoplanets provided that different regions are visible at different times -- this can be due to rotation, orbital motion, and occultations by a star, planet, or moon. Astronomers have so far constructed maps of thermal emission and albedo for short period giant exoplanets. These maps constrain atmospheric dynamics and cloud patterns in exotic atmospheres. In the future, exo-cartography could yield surface maps of terrestrial planets, hinting at the geophysical and geochemical processes that shape them.
description: To be published in: Handbook of Exoplanets, 2nd Edition, Hans Deeg and Juan Antonio Belmonte (Eds. in Chief), Springer International Publishing AG, part of Springer Nature. 19 pages, including 6 figures and 5 pages of references
Compact Perturbative Expressions For Neutrino Oscillations in Matter
Creators: name: Denton, Peter B.
name: Minakata, Hisakazu
name: Parke, Stephen J.
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: We further develop and extend a recent perturbative framework for neutrino oscillations in uniform matter density so that the resulting oscillation probabilities are accurate for the complete matter potential versus baseline divided by neutrino energy plane. This extension also gives the exact oscillation probabilities in vacuum for all values of baseline divided by neutrino energy. The expansion parameter used is related to the ratio of the solar to the atmospheric $Δm^2$ scales but with a unique choice of the atmospheric $Δm^2$ such that certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using a mixing matrix formulation, this framework has the exceptional feature that the neutrino oscillation probability in matter has the same structure as in vacuum, to all orders in the expansion parameter. It also contains all orders in the matter potential and $\sinθ_{13}$. It facilitates immediate physical interpretation of the analytic results, and makes the expressions for the neutrino oscillation probabilities extremely compact and very accurate even at zeroth order in our perturbative expansion. The first and second order results are also given which improve the precision by approximately two or more orders of magnitude per perturbative order.
description: 24 pages, 3 figures
CourtNet for Infrared Small-Target Detection
Creators: name: Peng, Jingchao
name: Zhao, Haitao
name: Zhao, Kaijie
name: Wang, Zhongze
name: Yao, Lujian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Infrared small-target detection (ISTD) is an important computer vision task. ISTD aims at separating small targets from complex background clutter. The infrared radiation decays over distances, making the targets highly dim and prone to confusion with the background clutter, which makes the detector challenging to balance the precision and recall rate. To deal with this difficulty, this paper proposes a neural-network-based ISTD method called CourtNet, which has three sub-networks: the prosecution network is designed for improving the recall rate; the defendant network is devoted to increasing the precision rate; the jury network weights their results to adaptively balance the precision and recall rate. Furthermore, the prosecution network utilizes a densely connected transformer structure, which can prevent small targets from disappearing in the network forward propagation. In addition, a fine-grained attention module is adopted to accurately locate the small targets. Experimental results show that CourtNet achieves the best F1-score on the two ISTD datasets, MFIRST (0.62) and SIRST (0.73).
ESPRESSO on VLT: An Instrument for Exoplanet Research
Creators: name: Hernández, Jonay I. González
name: Pepe, Francesco
name: Molaro, Paolo
name: Santos, Nuno
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: ESPRESSO (Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations) is a VLT ultra-stable high resolution spectrograph installed at ESO's Paranal Observatory in Chile at the end of 2017 and that started regular operations in October 2018. The spectrograph is located at the VLT Combined-Coudé Laboratory and is able to operate with one or (simultaneously) four 8.2m Unit Telescopes (UTs) through four optical Coudé trains. Combining efficiency and extreme spectroscopic precision, ESPRESSO has demonstrated to gain about two magnitudes with respect to its predecessor HARPS. ESPRESSO has improved the instrumental radial-velocity precision getting close to the aimed 10 cm/s level, thus opening the possibility to explore new frontiers in the search for Earth-mass exoplanets in the habitable zone of quiet, nearby G to M-dwarfs. ESPRESSO will be certainly an important development step towards high-precision ultra-stable spectrographs on the next generation of giant telescopes such as the ELT.
description: To be published in: Handbook of Exoplanets, 2nd Edition, Hans Deeg and Juan Antonio Belmonte (Eds. in Chief), Springer International Publishing AG, part of Springer Nature
The latent state hazard model, with application to wind turbine reliability
Creators: name: Moghaddass, Ramin
name: Rudin, Cynthia
Publisher: name: arXiv
Year: 2016
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: We present a new model for reliability analysis that is able to distinguish the latent internal vulnerability state of the equipment from the vulnerability caused by temporary external sources. Consider a wind farm where each turbine is running under the external effects of temperature, wind speed and direction, etc. The turbine might fail because of the external effects of a spike in temperature. If it does not fail during the temperature spike, it could still fail due to internal degradation, and the spike could cause (or be an indication of) this degradation. The ability to identify the underlying latent state can help better understand the effects of external sources and thus lead to more robust decision-making. We present an experimental study using SCADA sensor measurements from wind turbines in Italy.
description: Published at http://dx.doi.org/10.1214/15-AOAS859 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)
From thin plates to Ahmed bodies: linear and weakly non-linear stability of rectangular prisms
Creators: name: Zampogna, G. A.
name: Boujo, E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study the stability of laminar wakes past three-dimensional rectangular prisms. The width-to-height ratio is set to $W/H=1.2$, while the length-to-height ratio $1/6
Who Posts, Who Shares, Who Tells Your Story: A content analysis on how the public interacts with sharenting
Creators: Taylor (Tess) E. Syrowik
Publisher: name: University of Alberta Library
Year: 2022

In today’s digitised society, people actively share their lives on social media networks, including

popular platforms like Instagram. For parents this can include sharing, and sometimes

oversharing, about their children. This is called sharenting, and previous research has shown that

it can impact privacy, consent, identity formation, physical and digital safety, and even result in

identity theft, Deepfakes, and impact parent-child relationships. While research in this area has

been increasing since 2016, the literature does not include significant research on how parents

are encouraged to share about their children by their social media networks. This led to my

research question, what are some ways that members of the public interact with sharenting and

how does this relate to current sharenting research? Through a content analysis on two cases,

this research is grounded in current literature and communication privacy management theory.

The findings inform readers of how social capital and positive reinforcement encourage

sharenting, and the conclusion provides research-grounded recommendations for how parents

can navigate the tension between protecting their child’s digital footprint and the social pressure

they are under to participate in sharenting.
Global Optimal Trajectory in Chaos and NP-Hardness
Creators: name: Latorre, Vittorio
name: Gao, David Yang
Publisher: name: arXiv
Year: 2015
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: This paper presents a new canonical duality methodology for solving general nonlinear dynamical systems. Instead of the conventional iterative methods, the discretized nonlinear system is first formulated as a global optimization problem via the least squares method. The canonical duality theory shows that this nonconvex minimization problem can be solved deterministically in polynomial time if a global optimality condition is satisfied. The so-called pseudo-chaos produced by Runge-Kutta type of linear iterations are mainly due to the intrinsic numerical error accumulations. Otherwise, the global optimization problem could be NP-hard and the nonlinear system can be really chaotic. A conjecture is proposed, which reveals the connection between chaos in nonlinear dynamics and NP-hardness in computer science. The methodology and the conjecture are verified by applications to the well-known logistic equation, a forced memristive circuit and the Lorenz system. Computational results show that the canonical duality theory can be used to identify chaotic systems and to obtain realistic global optimal solutions in nonlinear dynamical systems.
description: 10 pages, 22 figures
AARP Survey of Small Business Owners in Alabama
Creators: name: AARP
Publisher: name: Roper Center for Public Opinion Research
Year: 2023

description: Concern that employee(s) will not have enough money in retirement (1); currently saving for own retirement (1); offer employee retirement savings plan (11); concerns about operating/managing an employee retirement savings plan (3); main reason for offering employee retirement savings plan (1); concerns about non-savers being reliant on public assistance (1); support establishment of a state-private partnership in retirement savings program (4).
New Constraints on Warm Dark Matter from the Lyman-$α$ Forest Power Spectrum
Creators: name: Villasenor, Bruno
name: Robertson, Brant
name: Madau, Piero
name: Schneider, Evan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The forest of Lyman-$α$ absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable -- the 1D flux power spectrum (FPS) -- should exhibit a suppression on small scales and an enhancement on large scales in warm dark matter (WDM) cosmologies compared to standard $Λ$CDM. Here, we present an unprecedented suite of 1080 high-resolution cosmological hydrodynamical simulations run with the Graphics Processing Unit-accelerated code Cholla to study the evolution of the Lyman-$α$ forest under a wide range of physically-motivated gas thermal histories along with different free-streaming lengths of WDM thermal relics in the early Universe. A statistical comparison of synthetic data with the forest FPS measured down to the smallest velocity scales ever probed at redshifts $4.0\lesssim z\lesssim 5.2$ (Boera et al. 2019) yields a lower limit $m_{\rm WDM}>3.1$ keV (95 percent CL) for the WDM particle mass and constrains the amplitude and spectrum of the photoheating and photoionizing background produced by star-forming galaxies and active galactic nuclei at these redshifts. Interestingly, our Bayesian inference analysis appears to weakly favor WDM models with a peak likelihood value at the thermal relic mass of $m_{\rm WDM}=4.5$ keV. We find that the suppression of the FPS from free-streaming saturates at $k\gtrsim 0.1\,\mathrm{s}\,\mathrm{km}^{-1}$ because of peculiar velocity smearing, and this saturated suppression combined with a slightly lower gas temperature provides a moderately better fit to the observed small-scale FPS for WDM cosmologies.
description: Version accepted to Phys. Rev. D
AARP New York Survey of Small Business Owners
Creators: name: AARP
Publisher: name: Roper Center for Public Opinion Research
Year: 2023

description: Effect of coronavirus (COVID-19) pandemic on business (2); concern that employee(s) will not have enough money in retirement (1); offer employee retirement savings plan (2); concerns about operating/managing an employee retirement savings plan (3); concerns about non-savers relying on public assistance (1); NYS Secure Choice Savings Program (4).
ARTIFICIAL INTELLIGENCE: FROM A STEREOTYPE TO A COMMON SENSE KNOWLEDGE BASE
Creators: name: Elkhova, Oxana
Publisher: name: figshare
Year: 2023
Subjects: Philosophy of cognition
Philosophy of mind (excl. cognition)

description: At the present stage of its development, developments in the field of Artificial Intelligence are closely related to what is called the problem of creating a common sense knowledge base. Representing the common sense knowledge base has long been one of the main challenges of artificial intelligence. The first developments in the field of cognitive modeling of AI tried to avoid the problem of ordinary knowledge and get the maximum set of achievements. Such an attitude to the problem of the knowledge base of common sense, in fact, did not allow artificial intelligence to move a single step forward. However, already in the mid-seventies of the last century, the need to address this problem became obvious. Since the unsolved problem did not allow systems with Artificial Intelligence even to meet G. Simon’s prediction twenty years ago that in no more than twenty years «machines will be able to do any job that a person can do» .
Automatic acoustic detection of birds through deep learning: the first Bird Audio Detection challenge
Creators: name: Stowell, Dan
name: Stylianou, Yannis
name: Wood, Mike
name: Pamuła, Hanna
name: Glotin, Hervé
Publisher: name: arXiv
Year: 2018
Subjects: subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Assessing the presence and abundance of birds is important for monitoring specific species as well as overall ecosystem health. Many birds are most readily detected by their sounds, and thus passive acoustic monitoring is highly appropriate. Yet acoustic monitoring is often held back by practical limitations such as the need for manual configuration, reliance on example sound libraries, low accuracy, low robustness, and limited ability to generalise to novel acoustic conditions. Here we report outcomes from a collaborative data challenge showing that with modern machine learning including deep learning, general-purpose acoustic bird detection can achieve very high retrieval rates in remote monitoring data --- with no manual recalibration, and no pre-training of the detector for the target species or the acoustic conditions in the target environment. Multiple methods were able to attain performance of around 88% AUC (area under the ROC curve), much higher performance than previous general-purpose methods. We present new acoustic monitoring datasets, summarise the machine learning techniques proposed by challenge teams, conduct detailed performance evaluation, and discuss how such approaches to detection can be integrated into remote monitoring projects.
Kea: a new tool to obtain stellar parameters from low to moderate signal/noise and high-resolution Echelle spectra
Creators: name: Endl, Michael
name: Cochran, William D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In this paper we describe Kea a new spectroscopic fitting method to derive stellar parameters from moderate to low signal/noise, high-resolution spectra. We developed this new tool to analyze the massive data set of the Kepler mission reconnaissance spectra that we have obtained at McDonald Observatory. We use Kea to determine effective temperatures (T_eff), metallicity ([Fe/H]), surface gravity (log g) and projected rotational velocity (v sin i). Kea compares the observations to a large library of synthetic spectra that covers a wide range of different T_eff, [Fe/H] and log g values. We calibrated Kea on observations of well-characterized standard stars (the Kepler field "platinum" sample) which range in T_eff from 5000 to 6500 K, in [Fe/H] from -0.5 to +0.4 dex and in log g from 3.2 to 4.6 dex. We then compared the Kea results from reconnaissance spectra of 45 KOIs (Kepler Object of Interest) to stellar parameters derived from higher signal/noise spectra obtained with Keck/HIRES. We find typical uncertainties of 100 K in T_eff, 0.12 dex in [Fe/H] and 0.18 dex in log g.
description: 18 pages, 5 figures, accepted for publication in PASP
polyBERT: A chemical language model to enable fully machine-driven ultrafast polymer informatics
Creators: name: Kuenneth, Christopher
name: Ramprasad, Rampi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Polymers are a vital part of everyday life. Their chemical universe is so large that it presents unprecedented opportunities as well as significant challenges to identify suitable application-specific candidates. We present a complete end-to-end machine-driven polymer informatics pipeline that can search this space for suitable candidates at unprecedented speed and accuracy. This pipeline includes a polymer chemical fingerprinting capability called polyBERT (inspired by Natural Language Processing concepts), and a multitask learning approach that maps the polyBERT fingerprints to a host of properties. polyBERT is a chemical linguist that treats the chemical structure of polymers as a chemical language. The present approach outstrips the best presently available concepts for polymer property prediction based on handcrafted fingerprint schemes in speed by two orders of magnitude while preserving accuracy, thus making it a strong candidate for deployment in scalable architectures including cloud infrastructures.
The halo mass function and filaments in full cosmological simulations with fuzzy dark matter
Creators: name: May, Simon
name: Springel, Volker
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Fuzzy dark matter (FDM) is a dark matter candidate consisting of ultra-light scalar particles with masses around $10^{-22} \mathrm{eV}/c^2$, a regime where cold bosonic matter behaves as a collective wave rather than individual particles. It has increasingly attracted attention due to its rich phenomenology on astrophysical scales, with implications for the small-scale tensions present within the standard cosmological model, $Λ$CDM. Although constraints on FDM are accumulating in many different contexts, very few have been verified by self-consistent numerical simulations. We present new large numerical simulations of cosmic structure formation with FDM, solving the full Schrödinger-Poisson (SP) equations using the AxiREPO code, which implements a pseudo-spectral numerical method. Combined with our previous simulations, they allow us to draw a four-way comparison of matter clustering, contrasting results (such as power spectra) for each combination of initial conditions (FDM vs. CDM) and dynamics (SP vs. $N$-body). By disentangling the impact of initial conditions and non-linear dynamics, we can gauge the validity of approximate methods used in previous works, such as ordinary $N$-body simulations with an FDM initial power spectrum. Due to the comparatively large volume achieved in our FDM simulations, we are able to measure the FDM halo mass function from full wave simulations for the first time, and compare to previous results obtained using analytic or approximate approaches. We find that, due to the cut-off of small-scale power in the FDM power spectrum, haloes are linked via continuous, smooth, and dense filaments throughout the entire simulation volume (unlike for the standard $Λ$CDM power spectrum), posing significant challenges for reliably identifying haloes. We also investigate the density profiles of these filaments and compare to their CDM counterparts.
description: 18 pages, 13 figures; submitted to MNRAS
Orbital Feshbach Resonance: A "Wide" Narrow Resonance for Higher Transition Temperature Fermi Superfluid
Creators: name: Xu, Junjun
name: Zhang, Ren
name: Cheng, Yanting
name: Zhang, Peng
name: Qi, Ran
name: Zhai, Hui
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In this letter we show that the recently theoretically predicted and experimentally observed "orbital Feshbach resonance" in alkali-earth-like Yb-173 atom is a narrow resonance in energy, while it is hundreds Gauss wide in term of magnetic field strength, taking the advantage that the magnetic moment difference between the open and closed channels is quite small. Therefore this is an ideal platform for the experimental realization of a strongly interacting Fermi superfluid with narrow resonance. We show that the transition temperature for the Fermi superfluid in this system, especially at the BCS side of the resonance, is even higher than that in a wide resonance, which is also due to the narrow character of this resonance. Our results will encourage experimental efforts to realize Fermi superfluid in the alkali-earth-like Yb-173 system, the properties of which will be complementary to extensively studied Fermi superfluids nearby a wide resonance in alkali K-40 and Li-6 systems.
description: 10 pages, 5 figures
Chemical Kinetics, Markov Chains, and the Imaginary Itô Interpretation
Creators: name: Correales, Álvaro
name: Escudero, Carlos
name: Ptashnyk, Mariya
Publisher: name: arXiv
Year: 2019
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The abstract chemical reaction $$ A+A \to \emptyset, $$ understood as a Markov chain in continuous time, has been studied in the physical literature for several years. It has been claimed that this reaction can be described by means of the stochastic differential equation $$ d ϕ= - ϕ^2 dt + i \, ϕ\, dW_t, $$ where $i$ is the imaginary unit. This affirmation is, at least, intriguing, and has led to controversy and criticisms in the literature. The goal of this work is to give partial evidence that such a description may be possible.
Hyperspectral Remote Sensing Benchmark Database for Oil Spill Detection with an Isolation Forest-Guided Unsupervised Detector
Creators: name: Duan, Puhong
name: Kang, Xudong
name: Ghamisi, Pedram
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Oil spill detection has attracted increasing attention in recent years since marine oil spill accidents severely affect environments, natural resources, and the lives of coastal inhabitants. Hyperspectral remote sensing images provide rich spectral information which is beneficial for the monitoring of oil spills in complex ocean scenarios. However, most of the existing approaches are based on supervised and semi-supervised frameworks to detect oil spills from hyperspectral images (HSIs), which require a huge amount of effort to annotate a certain number of high-quality training sets. In this study, we make the first attempt to develop an unsupervised oil spill detection method based on isolation forest for HSIs. First, considering that the noise level varies among different bands, a noise variance estimation method is exploited to evaluate the noise level of different bands, and the bands corrupted by severe noise are removed. Second, kernel principal component analysis (KPCA) is employed to reduce the high dimensionality of the HSIs. Then, the probability of each pixel belonging to one of the classes of seawater and oil spills is estimated with the isolation forest, and a set of pseudo-labeled training samples is automatically produced using the clustering algorithm on the detected probability. Finally, an initial detection map can be obtained by performing the support vector machine (SVM) on the dimension-reduced data, and then, the initial detection result is further optimized with the extended random walker (ERW) model so as to improve the detection accuracy of oil spills. Experiments on airborne hyperspectral oil spill data (HOSD) created by ourselves demonstrate that the proposed method obtains superior detection performance with respect to other state-of-the-art detection approaches.
Self-Propelled Pedestrian Dynamics Model: Application to Passenger Movement and Infection Propagation in Airplanes
Creators: name: Namilae, S.
name: Srinivasan, A.
name: Mubayi, A.
name: Scotch, M.
name: Pahle, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Reducing the number of contacts between passengers on an airplane can potentially curb the spread of infectious diseases. In this paper, a social force based pedestrian movement model is formulated and applied to evaluate the movement and contacts among passengers during boarding and deplaning of an airplane. Within the social force modeling framework, we introduce location dependence on the self-propelling momentum of pedestrian particles. The model parameters are varied over a large design space and the results are compared with experimental observations to validate the model. This model is then used to assess the different approaches to minimize passenger contacts during boarding and deplaning of airplanes. We find that smaller aircrafts are effective in reducing the contacts between passengers. Column wise deplaning and random boarding are found to be two strategies that reduced the number of contacts during passenger movement, and can potentially lower the likelihood of infection spread.
Challenges with Internal Photons in Constructive QED
Creators: name: Christensen, Neil
name: Diaz-Quiroz, Harold
name: Field, Bryan
name: Hayward, Justin
name: Miles, John
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We find the correct spinor amplitude for a simple photon-mediated process and show that, in contrast, the result for the same process using the standard constructive techniques do not agree with Feynman diagrams when the fermions are massive. Along the way, we analyze the $x$ factor used in photon vertices, we work out the spinor shifts for massive particles when the momenta are analytically continued and we consider the large $z$ limit of the amplitudes in this paper and show that the photon-mediated process does not vanish in this limit for any choice of two of its momenta. For comparison with the photon-mediated process, we also describe two processes with external photons that are mediated by massive particles. In both cases, we show that the current techniques are sufficient and that the final results agree with Feynman diagrams. We also demonstrate that by using a massive photon in our calculations and taking the massless limit at the end, we can achieve agreement with Feynman diagrams in all the processes discussed here, including the photon-mediated amplitudes.
description: 40 pages, 0 figures
Common Onomatopoeia in Ihanzu
Creators: name: Holmes, Amber
Publisher: name: Zenodo
Year: 2023
Subjects: Languages of Tanzania
Language Documentation and Description
Niger-Congo
Bantu
Ihanzu
Isanzu
Onomatopoeia

description: A presentation on common onomatopoeia, given at the Ihanzu Symposium.
description: Note: This talk has not gone through a process of peer review, and findings should therefore be treated as preliminary and subject to change. Acknowledgement and citation: Holmes, Amber. 2023. Common Onomatopoeia in Ihanzu. Talk given at the Ihanzu Symposium 2023, Bielefeld University, Germany. 29/09/2023.
Guided Unsupervised Learning by Subaperture Decomposition for Ocean SAR Image Retrieval
Creators: name: Ristea, Nicolae-Cătălin
name: Anghel, Andrei
name: Datcu, Mihai
name: Chapron, Bertrand
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Spaceborne synthetic aperture radar (SAR) can provide accurate images of the ocean surface roughness day-or-night in nearly all weather conditions, being an unique asset for many geophysical applications. Considering the huge amount of data daily acquired by satellites, automated techniques for physical features extraction are needed. Even if supervised deep learning methods attain state-of-the-art results, they require great amount of labeled data, which are difficult and excessively expensive to acquire for ocean SAR imagery. To this end, we use the subaperture decomposition (SD) algorithm to enhance the unsupervised learning retrieval on the ocean surface, empowering ocean researchers to search into large ocean databases. We empirically prove that SD improve the retrieval precision with over 20% for an unsupervised transformer auto-encoder network. Moreover, we show that SD brings important performance boost when Doppler centroid images are used as input data, leading the way to new unsupervised physics guided retrieval algorithms.
A model of membrane deformations driven by a surface pH gradient
Creators: name: Mendes, Toni V.
name: Ranft, Jonas
name: Berthoumieux, Hélène
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Many cellular organelles are membrane-bound structures with complex membrane composition and shape. Their shapes have been observed to depend on the metabolic state of the organelle, and the mechanisms that couple biochemical pathways and membrane shape are still actively investigated. Here, we study a model coupling inhomogeneities in the lipid composition and membrane geometry via a generalized Helfrich free energy. We derive the resulting stress tensor, the Green's function for a tubular membrane and compute the phase diagram of the induced deformations. We then apply this model to study the deformation of mitochondria cristae described as membrane tubes supporting a pH gradient at its surface. This gradient in turn controls the lipid composition of the membrane via the protonation/deprotonation of cardiolipins, which are acid-based lipids known to be crucial for mitochondria shape and functioning. Our model predicts the appearance of tube deformations resembling the observed shape changes of cristea when submitted to a proton gradient.
description: 10 pages, 3 figures
Improving PWR core simulations by Monte Carlo uncertainty analysis and Bayesian inference
Creators: name: Castro, Emilio
name: Ahnert, Carolina
name: Buss, Oliver
name: Garcia-Herranz, Nuria
name: Hoefer, Axel
name: Porsch, Dieter
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: A Monte Carlo-based Bayesian inference model is applied to the prediction of reactor operation parameters of a PWR nuclear power plant. In this non-perturbative framework, high-dimensional covariance information describing the uncertainty of microscopic nuclear data is combined with measured reactor operation data in order to provide statistically sound, well founded uncertainty estimates of integral parameters, such as the boron letdown curve and the burnup-dependent reactor power distribution. The performance of this methodology is assessed in a blind test approach, where we use measurements of a given reactor cycle to improve the prediction of the subsequent cycle. As it turns out, the resulting improvement of the prediction quality is impressive. In particular, the prediction uncertainty of the boron letdown curve, which is of utmost importance for the planning of the reactor cycle length, can be reduced by one order of magnitude by including the boron concentration measurement information of the previous cycle in the analysis. Additionally, we present first results of non-perturbative nuclear-data updating and show that predictions obtained with the updated libraries are consistent with those induced by Bayesian inference applied directly to the integral observables.
description: 10 pages, 11 figures
Macroscopic behavior of Lipschitz random surfaces
Creators: name: Lammers, Piet
name: Tassy, Martin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 82B20, 82B41, 60F10, 82B30 (Primary)

description: The motivation for this article is to derive strict convexity of the surface tension for Lipschitz random surfaces, that is, for models of random Lipschitz functions from $\mathbb Z^d$ to $\mathbb Z$ or $\mathbb R$. An essential innovation is that random surface models with long- and infinite-range interactions are included in the analysis. More specifically, we cover at least: uniformly random graph homomorphisms from $\mathbb Z^d$ to a $k$-regular tree for any $k\geq 2$ and Lipschitz potentials which satisfy the FKG lattice condition. The latter includes perturbations of dimer- and six-vertex models and of Lipschitz simply attractive potentials introduced by Sheffield. The main result is that we prove strict convexity of the surface tension -- which implies uniqueness for the limiting macroscopic profile -- if the model of interest is monotone in the boundary conditions. This solves a conjecture of Menz and Tassy, and answers a question posed by Sheffield. Auxiliary to this, we prove several results which may be of independent interest, and which do not rely on the model being monotone. This includes existence and topological properties of the specific free energy, as well as a characterization of its minimizers. We also prove a general large deviations principle which describes both the macroscopic profile and the local statistics of the height functions. This work is inspired by, but independent of, Random Surfaces by Sheffield.
description: 88 pages, 8 figures
Homotopy liftings and Hochschild cohomology of some twisted tensor products
Creators: name: Ocal, Pablo S.
name: Oke, Tolulope
name: Witherspoon, Sarah
Publisher: name: arXiv
Year: 2020
Subjects: subject: Rings and Algebras (math.RA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: The Hochschild cohomology of a tensor product of algebras is isomorphic to a graded tensor product of Hochschild cohomology algebras, as a Gerstenhaber algebra. A similar result holds when the tensor product is twisted by a bicharacter. We present new proofs of these isomorphisms, using Volkov's homotopy liftings that were introduced for handling Gerstenhaber brackets expressed on arbitrary bimodule resolutions. Our results illustrate the utility of homotopy liftings for theoretical purposes.
description: 14 pages, minor reference corrections, added Section 4 with examples