cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
An adaptive robust optimization model for parallel machine scheduling
Creators: name: Cohen, Izack
name: Postek, Krzysztof
name: Shtern, Shimrit
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Real-life parallel machine scheduling problems can be characterized by: (i) limited information about the exact task duration at scheduling time, and (ii) an opportunity to reschedule the remaining tasks each time a task processing is completed and a machine becomes idle. Robust optimization is the natural methodology to cope with the first characteristic of duration uncertainty, yet the existing literature on robust scheduling does not explicitly consider the second characteristic - the possibility to adjust decisions as more information about the tasks' duration becomes available, despite that re-optimizing the schedule every time new information emerges is standard practice. In this paper, we develop a scheduling approach that takes into account, at the beginning of the planning horizon, the possibility that scheduling decisions can be adjusted. We demonstrate that the suggested approach can lead to better here-and-now decisions and better makespan guarantees. To that end, we develop the first mixed integer linear programming model for adjustable robust scheduling, and a scalable two-stage approximation heuristic, where we minimize the worst-case makespan. Using this model, we show via a numerical study that adjustable scheduling leads to solutions with better and more stable makespan realizations compared to static approaches.
Meridional tilt of the stellar velocity ellipsoid during bar buckling instability
Creators: name: Saha, Kanak
name: Pfenniger, Daniel
name: Taam, Ronald E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The structure and evolution of the stellar velocity ellipsoid plays an important role in shaping galaxies undergoing bar driven secular evolution and the eventual formation of a boxy/peanut bulge such as present in the Milky Way. Using collisionless N-body simulations, we show that during the formation of such a boxy/peanut bulge, the meridional shear stress of stars, which can be measured by the meridional tilt of the velocity ellipsoid, reaches a characteristic peak in its time evolution. It is shown that the onset of a bar buckling instability is closely connected to the maximum meridional tilt of the stellar velocity ellipsoid. Our findings bring new insight to this complex gravitational instability of the bar which complements the buckling instability studies based on orbital models. We briefly discuss the observed diagnostics of the stellar velocity ellipsoid during such a phenomenon.
description: 10 pages, 16 Figures, accepted by the ApJ
Endectyon (Endectyon) hyle
Creators: name: Trejo, Alejandra
name: Carballo, José Luis
name: Segovia, Johanna
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Axinellida
Raspailiidae
Endectyon
Endectyon hyle

description: Endectyon (Endectyon) hyle (de Laubenfels, 1930)
Figure 5, Table 5
Examined material. MUHNES-91-52 — El Candado (13°30’40.6”N, 89°47’56.7”W), depth 6 m, A. Trejo (19. VI.2018).
Description. Branched sponge 3 cm wide and 5 cm high. Each branch of the sponge has two rounded lobes, each 0.5 cm in diameter (Figure 5A). The surface is irregular, no oscula are observed. Hard consistency and difficult to break. Color in life is bright orange with fine sediment on it, when preserved in alcohol it turns beige. The ectosome consists of a layer of straight, long and thin styles (200–250 x 1–2 µm) (Figure 5B). There is an extra-axial subectosome made up of styles that project their tips toward the surface. The choanosome is a compressed axial skeleton formed by primary multispicular fibers interconnected by secondary fibers of two or more spicules, where styles and acanthostyles meet (Figure 5C). The species presents styles in two categories, those of the ectosome that are straight and very thin, while those of the sub ectosome and choanosome are robust, with a sharp point and some are curved in the middle or in the third region closest to the head, the acanthostyles are stout with prominent spines from the mid-region to the tip of the spicule (Figure 5D–F).
Ecological notes. The species was found on sandy substrate at 6 m depth.
Distribution and previous records. The species was described by de Laubenfels in 1930 from California. Reports have been made from Galapagos Islands (Desqueyroux-Faúndez & Van Soest 1997) and Mexican Pacific Ocean (Aguilar-Camacho & Carballo 2013). In El Salvador, the species has been recorded in Punta Amapala (Trejo & Segovia 2024). Here we extend the species distribution in the country to Los Cóbanos (Table 12).
Remarks. The specimen is similar to the original description in skeletal arrangement and spicule composition (De Laubenfels 1932), although, the size of our specimen is slightly larger, up to 5 cm high. Also, in the type specimen there are two size categories of choanosome styles, unlike our specimen where only one size category was found. Aguilar-Camacho et al. (2013) also describe specimens with a single size category of choanosome style, but these are much larger than the ones reported here (up to 780 µm length).
description: Published as part of Trejo, Alejandra, Carballo, José Luis & Segovia, Johanna, 2025, New records and checklist of sponges from El Salvador (Eastern Tropical Pacific), pp. 99-125 in Zootaxa 5613 (1) on pages 106-107, DOI: 10.11646/zootaxa.5613.1.4, http://zenodo.org/record/15216236
Solution of the Basel problem in the framework of distribution theory
Creators: name: Aste, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 40A25, 46F05

description: A simple proof of Euler's formula which states that the sum of the reciprocals of all natural numbers squared equals $π^2/6$ is presented based on the distribution theory introduced by Laurent Schwartz. Additional identities are obtained as a byproduct of the derivation.
description: 6 pages, 1 figure. La Matematica (2023)
GUP corrected entropy of the Schwarzschild black hole in holographic massive gravity
Creators: name: Hong, Soon-Tae
name: Kim, Yong-Wan
name: Park, Young-Jai
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We obtain the statistical entropy of a scalar field on the Schwarzschild black hole in holographic massive gravity by considering corrections on the density of quantum states to all orders in the Planck length from a generalized uncertainty principle (GUP). As a result, we find not only the generalized Bekenstein-Hawking entropy depending on holographically massive gravitons without any artificial cutoff, but also new additional correction terms, which are proportional to surface gravity. Moreover, we also observe that all order GUP corrected entropy is improved to have smaller GUP parameter $λ$ than the previous results.
description: 12 pages, 3 figures, version to appear in MPLA
Computing hydrodynamic eigenmodes of channel flow with slip -- A highly accurate algorithm
Creators: name: Raju, S.
name: Gründing, D.
name: Marić, T.
name: Bothe, D.
name: Fricke, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The transient start-up flow solution with slip is a useful tool to verify Computational Fluid Dynamics (CFD) simulations. However, a highly accurate, open-source black box solution does not seem to be available. Our method provides a fast, automated, and rigorously verified open-source implementation that can compute the hydrodynamic eigenmodes of a two-dimensional channel flow beyond the standard floating-point precision. This allows for a very accurate computation of the corresponding Fourier series solution. We prove that all roots are found in all special cases for the general flow problem with different slip lengths on the channel walls. The numerical results confirm analytically derived asymptotic power laws for the leading hydrodynamic eigenmode and the characteristic timescale in the limiting cases of small and large slip. The code repository including test cases is publicly available here https://git.rwth-aachen.de/fricke/start-up-flow
description: 29 pages, 10 figures, article manuscript
Cyber-Attack Detection in Socio-Technical Transportation Systems Exploiting Redundancies Between Physical and Social Data
Creators: name: Roy, Tanushree
name: Sattarzadeh, Sara
name: Dey, Satadru
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: Cyber-physical-social connectivity is a key element in Intelligent Transportation Systems (ITSs) due to the ever-increasing interaction between human users and technological systems. Such connectivity translates the ITSs into dynamical systems of socio-technical nature. Exploiting this socio-technical feature to our advantage, we propose a cyber-attack detection scheme for ITSs that focuses on cyber-attacks on freeway traffic infrastructure. The proposed scheme combines two parallel macroscopic traffic model-based Partial Differential Equation (PDE) filters whose output residuals are compared to make decision on attack occurrences. One of the filters utilizes physical (vehicle/infrastructure) sensor data as feedback whereas the other utilizes social data from human users' mobile devices as feedback. The Social Data-based Filter is aided by a fake data isolator and a social signal processor that translates the social information into usable feedback signals. Mathematical convergence properties are analyzed for the filters using Lyapunov's stability theory. Lastly, we validate our proposed scheme by presenting simulation results.
description: in IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2023
Environmental Racism and the Maasai Predicament in Ngorongoro
Creators: name: Singo, Leiyo
Publisher: name: University of Tübingen
Year: 2023

description: In this blog post I provide an insider's perspective on environmental racism and the Maasai predicament in Ngorongoro, Tanzania. I historicize the recent evictions of the Maasai pastoralists by unpacking colonial racist logics that rationalize othering, dispossession and displacements.
The Penrose Property with a Cosmological Constant
Creators: name: Cameron, Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A spacetime satisfies the non-timelike boundary version of the Penrose property if the timelike future of any point on $\mathcal{I}^-$ contains the whole of $\mathcal{I}^+$. This property was first discussed for asymptotically flat spacetimes by Penrose, along with an equivalent definition (the finite version). In this paper we consider the Penrose property in greater generality. In particular we consider spacetimes with a non-zero cosmological constant and we note that the two versions of the property are no longer equivalent. In asymptotically AdS spacetimes it is necessary to re-state the property in a way which is more suited to spacetimes with a timelike boundary. We arrive at a property previously considered by Gao and Wald. Curiously, this property was shown to fail in spacetimes which focus null geodesics. This is in contrast to our findings in asymptotically flat and asymptotically de Sitter spacetimes. We then move on to consider some further example spacetimes (with zero cosmological constant) which highlight features of the Penrose property not previously considered. We discuss spacetimes which are the product of a Lorentzian and a compact Riemannian manifold. Perhaps surprisingly, we find that both versions of the Penrose property are satisfied in this product spacetime if and only if they are satisfied in the Lorentzian spacetime only. We also discuss the Ellis-Bronnikov wormhole (an example of a spacetime with more than one asymptotically flat end) and the Hayward metric (an example of a non-singular black hole spacetime).
A comprehensive comparison of cosmological models from latest observational data
Creators: name: Shi, Ke
name: Huang, Yongfeng
name: Lu, Tan
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We investigate in detail some popular cosmological models in light of the latest observational data, including the Union2.1 supernovae compilation, the baryon acoustic oscillation measurements from the WiggleZ Dark Energy Survey, the cosmic microwave background information from the WMAP 7-year observations along with the observational Hubble parameter data. Based on the model selection statistics such as the Akaike and the Bayesian information criterias, we compare different models to assess the worth of them. We do not assume a flat universe in the fitting. Our results show that the concordance $Λ$CDM model remains the best one to explain the data, while the DGP model is clearly disfavored by the data. Among these models, those whose parameters can reduce themselves to the $Λ$CDM model provide good fits to the data. These results indicate that for the current data, there is no obvious evidence supporting any more complex models over the simplest $Λ$CDM model.
description: 17 pages, 9 figures, 2 tables, accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal
American Citizens: The Politics of Graffiti and Public Space in Chicago
Creators: name: Idowu, Mojolaoluwa
Publisher: name: University of Chicago
Year: 2018
Subjects: subject: graffiti
subject: West Side
subject: arts & culture

description: My project explores how graffiti writers in Chicago interact with public space in order to determine the sites of their work. Through the process of my project, I came to the conclusion that writers utilize a framework of foot traffic, hard to buff areas, public spaces, and risk in order to determine prime tagging/writing spots. However, in the search for this framework, I also discovered contradictions to these rules pertaining to commissioned and legalized graffiti. Graffiti commissioned by the Chicago municipal government and corporate entities does not incorporate traits that interest graffiti writers such as risk, and increases other traits such as hard to buff. The conflation of the formal qualities of graffiti with the social site produces a version of beauty that relies on state antagonism in order to satisfy its social value. However, through commissions by the City of Chicago and companies, graffiti's beauty becomes defined by the state and corporate understandings of beauty, and is removed partly from the social aspect of its beauty.
Chandra Observations of Black-Widow Pulsars
Creators: name: Gentile, Peter
name: McLaughlin, Maura
name: Roberts, Mallory
name: Camilo, Fernando
name: Hessels, Jason
name: Kerr, Matthew
name: Ransom, Scott
name: Ray, Paul
name: Stairs, Ingrid
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We describe the first X-ray observations of binary millisecond pulsars PSRs J0023+0923, J1810+1744, J2215+5135, and J2256-1024. All four are Fermi gamma-ray sources and three are 'black-widow' pulsars, with companions of mass < 0.1 solar masses. Data were taken using the Chandra X-Ray Observatory and covered a full binary orbit for each pulsar. Two pulsars, PSRs J2215+5135 and J2256-1024, show significant orbital variability and X-ray flux minima at the times of eclipses observed at radio wavelengths. This phenomenon is consistent with intrabinary shock emission characteristic of black-widow pulsars. The other two pulsars, PSRs J0023+0923 and J1810+1744, do not demonstrate significant variability, but are fainter than the other two sources. Spectral fits yield power-law indices that range from 1.4 to 2.3 and blackbody temperatures in the hundreds of eV. The spectrum for PSR J2215+5135 shows a significant hard X-ray component (41% of counts are above 2 keV), which is additional evidence for the presence of intrabinary shock emission.
description: 3 pages, 2 figures, 1 table, 2012 IAU General Assembly
Vortexons in axisymmetric Poiseuille pipe flows
Creators: name: Fedele, Francesco
name: Dutykh, Denys
Publisher: name: arXiv
Year: 2012
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Analysis of PDEs (math.AP)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Classical Physics (physics.class-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We present a study on the nonlinear dynamics of small long-wave disturbances to the laminar state in non-rotating axisymmetric Poiseuille pipe flows. At high Reynolds numbers, the associated Navier-Stokes equations can be reduced to a set of coupled Korteweg-de Vries-type (KdV) equations that support inviscid and smooth travelling waves numerically computed using the Petviashvili method. In physical space they correspond to localized toroidal vortices concentrated near the pipe boundaries (wall vortexons) or that wrap around the pipe axis (centre vortexons), in agreement with the analytical soliton solutions derived by Fedele (2012). The KdV dynamics of a perturbation is also investigated by means of an high accurate Fourier-based numerical scheme. We observe that an initial vortical patch splits into a centre vortexon radiating patches of vorticity near the wall. These can undergo further splitting leading to a proliferation of centre vortexons that eventually decay due to viscous effects. The splitting process originates from a radial flux of azimuthal vorticity from the wall to the pipe axis in agreement with the inverse cascade of cross-stream vorticity identified in channel flows by Eyink (2008). The inviscid vortexon most likely is unstable to non-axisymmetric disturbances and may be a precursor to puffs and slug flow formation.
description: 13 pages, 6 figures, 46 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/. arXiv admin note: substantial text overlap with arXiv:1211.7349, arXiv:1211.4233
Stability of elliptic function solutions for the focusing modified KdV equation
Creators: name: Ling, Liming
name: Sun, Xuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the spectral and orbital stability of elliptic function solutions for the focusing modified Korteweg-de Vries (mKdV) equation and construct the corresponding breather solutions to exhibit the stable or unstable dynamic behavior. The elliptic function solutions of the mKdV equation and related fundamental solutions of the Lax pair are exactly represented by theta functions. Based on the `modified squared wavefunction' (MSW) method, we construct all linear independent solutions of the linearized mKdV equation and then provide a necessary and sufficient condition of the spectral stability for elliptic function solutions with respect to subharmonic perturbations. In the case of spectrum stability, the orbital stability of elliptic function solutions is established in a suitable Hilbert space. Using Darboux-Bäcklund transformation, we construct breather solutions to exhibit unstable or stable dynamic behavior. Through analyzing the asymptotic behavior, we find that the breather solution under the cn-type solution background is equivalent to the elliptic function solution adding a small perturbation as $t\to\pm\infty$.
description: 43pages, 10 figures
Partial Maximum Correntropy Regression for Robust Trajectory Decoding from Noisy Epidural Electrocorticographic Signals
Creators: name: Li, Yuanhao
name: Chen, Badong
name: Wang, Gang
name: Yoshimura, Natsue
name: Koike, Yasuharu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The Partial Least Square Regression (PLSR) exhibits admirable competence for predicting continuous variables from inter-correlated brain recordings in the brain-computer interface. However, PLSR is in essence formulated based on the least square criterion, thus, being non-robust with respect to noises. The aim of this study is to propose a new robust implementation for PLSR. To this end, the maximum correntropy criterion (MCC) is used to propose a new robust variant of PLSR, called as Partial Maximum Correntropy Regression (PMCR). The half-quadratic optimization is utilized to calculate the robust projectors for the dimensionality reduction, and the regression coefficients are optimized by a fixed-point approach. We evaluate the proposed PMCR with a synthetic example and the public Neurotycho electrocorticography (ECoG) datasets. The extensive experimental results demonstrate that, the proposed PMCR can achieve better prediction performance than the conventional PLSR and existing variants with three different performance indicators in high-dimensional and noisy regression tasks. PMCR can suppress the performance degradation caused by the adverse noise, ameliorating the decoding robustness of the brain-computer interface.
Gerhard Baaken, Ius Imperii ad Regnum, Königreich Sizilien, Imperium Romanum und Römisches Papsttum vom Tode Kaiser Heinich VI. bis zu den Verzichterklärungen Rudolfs von Habsburg, 1993
Creators: name: Martin, Jean-Marie
Publisher: name: Francia
Year: 2019

description: -
description: Francia, Bd. 23 Nr. 1 (1996)
Hitting the Target: Stopping Active Learning at the Cost-Based Optimum
Creators: name: Pullar-Strecker, Zac
name: Dost, Katharina
name: Frank, Eibe
name: Wicker, Jörg
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Active learning allows machine learning models to be trained using fewer labels while retaining similar performance to traditional supervised learning. An active learner selects the most informative data points, requests their labels, and retrains itself. While this approach is promising, it raises the question of how to determine when the model is `good enough' without the additional labels required for traditional evaluation. Previously, different stopping criteria have been proposed aiming to identify the optimal stopping point. Yet, optimality can only be expressed as a domain-dependent trade-off between accuracy and the number of labels, and no criterion is superior in all applications. As a further complication, a comparison of criteria for a particular real-world application would require practitioners to collect additional labelled data they are aiming to avoid by using active learning in the first place. This work enables practitioners to employ active learning by providing actionable recommendations for which stopping criteria are best for a given real-world scenario. We contribute the first large-scale comparison of stopping criteria for pool-based active learning, using a cost measure to quantify the accuracy/label trade-off, public implementations of all stopping criteria we evaluate, and an open-source framework for evaluating stopping criteria. Our research enables practitioners to substantially reduce labelling costs by utilizing the stopping criterion which best suits their domain.
description: 20 pages, 7 figures
Are molecular outflows around high-mass stars driven by ionization feedback?
Creators: name: Peters, Thomas
name: Klaassen, Pamela D.
name: Mac Low, Mordecai-Mark
name: Klessen, Ralf S.
name: Banerjee, Robi
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The formation of massive stars exceeding 10 solar masses usually results in large-scale molecular outflows. Numerical simulations, including ionization, of the formation of such stars show evidence for ionization-driven molecular outflows. We here examine whether the outflows seen in these models reproduce the observations. We compute synthetic ALMA and CARMA maps of CO emission lines of the outflows, and compare their signatures to existing single-dish and interferometric data. We find that the ionization-driven models can only reproduce weak outflows around high-mass star-forming regions. We argue that expanding H II regions probably do not represent the dominant mechanism for driving observed outflows. We suggest instead that observed outflows are driven by the collective action of the outflows from the many lower-mass stars that inevitably form around young massive stars in a cluster.
description: Movies can be found here
Joseph Avril (Hrsg.), Les statuts synodaux français du XIIIe siècle. T. IV: Les statuts de l'ancienne province ecclésiastique de Reims (Cambrai, Arras, Noyon, Soissons, Tournai), 1995
Creators: name: Müller, Heribert
Publisher: name: Francia
Year: 2019

description: -
description: Francia, Bd. 23 Nr. 1 (1996)
Approximately multiplicative maps between algebras of bounded operators on Banach spaces
Creators: name: Choi, Yemon
name: Horváth, Bence
name: Laustsen, Niels Jakob
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: Primary 39B82, 47L10, Secondary 46B03, 46M18, 47B49

description: We show that for any separable reflexive Banach space $X$ and a large class of Banach spaces $E$, including those with a subsymmetric shrinking basis but also all spaces $L_p$ for $1\leq p \leq \infty$, every bounded linear map ${\mathcal B}(E)\to {\mathcal B}(X)$ which is approximately multiplicative is necessarily close in the operator norm to some bounded homomorphism ${\mathcal B}(E)\to {\mathcal B}(X)$. That is, the pair $({\mathcal B}(E), {\mathcal B}(X))$ has the AMNM property in the sense of Johnson (\textit{J.~London Math.\ Soc.} 1988). Previously this was only known for $E=X=\ell_p$ with $1
description: v1: AMS-LaTeX, 30 pages. Submitted for publication. v2: incorporates revisions based on feedback from referee; minor updates/corrections to bibliography. Final accepted version, to appear in Trans. Amer. Math. Soc
Determining distances using asteroseismic methods
Creators: name: Aguirre, V. Silva
name: Casagrande, L.
name: Basu, S.
name: Campante, T. L.
name: Chaplin, W. J.
name: Huber, D.
name: Miglio, A.
name: Serenelli, A. M.
name: WG#1, KASC
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the results is needed. In this talk, I present a new technique developed to obtain stellar properties by coupling asteroseismic analysis with the InfraRed Flux Method. Using two global seismic observables and multi-band photometry, the technique determines masses, radii, effective temperatures, bolometric fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\it Kepler} field that have accurate {\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements of spectroscopic effective temperatures and interferometric radii also validate our results, and show that our technique can be applied to stars evolved beyond the main-sequence phase.
description: 4 pages, to appear in the Proceedings of the 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, eds. K. Strassmeier & M. Lopez-Morales (AN, Vol. 334)
Planetary accretion and core formation inferred from Ni isotopes in enstatite meteorites
Creators: name: Zhu, Ke
name: Becker, Harry
name: Zhu, J.-M.
name: Xu, H.-P.
name: Man, Q.-R.
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: Ni stable isotopes
subject: enstatite meteorites
subject: aubrites
subject: core formation
subject: metal-sulfide segregation
subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften

description: Nickel is a siderophile and near-refractory element, making its isotopes a potential tool for tracing planetary accretion and differentiation. However, the origin of the Ni stable isotope difference between bulk silicate Earth (BSE) and chondrites remains enigmatic. To address this problem, we report high precision Ni stable isotope data of enstatite chondrites and achondrites that possess similar mass independent O and Ni isotope compositions like the Earth-Moon system. Bulk enstatite chondrites have δ60/58Ni values of 0.24 ± 0.08 ‰ (2 s.d., n = 13). Enstatite achondrites, including main-group aubrites, Shallowater and Itqiy, show relatively large δ60/58Ni variations, ranging from 0.03 ± 0.02 ‰ to 0.57 ± 0.04 ‰. This could reflect fractionations between sulfide and metal phases, as is evidenced by correlation between their S/Ni ratios and δ60/58Ni values. In enstatite achondrites, Ni is mainly hosted in metal and to a lesser extent in sulfides, so δ60/58Ni values in enstatite achondrites may represent the Ni isotopic values of the cores of their parent bodies. The overlapping δ60/58Ni values between bulk enstatite achondrites and enstatite chondrites indicate limited Ni stable isotope fractionation during core formation processes on reduced, sulfur-rich parent bodies. The Ni stable isotope gap between chondrites and the BSE could be possibly explained by chondrule-rich accretion model.
A mapping study of L1174 with 13CO J=2-1 and 12CO J=3-2: star formation triggered by a Herbig Ae/Be star
Creators: name: Yuan, J. H.
name: Wu, Y.
name: Li, J. Z.
name: Yu, W.
name: Miller, M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We have carried out a comprehensive study of the molecular conditions and star-forming activities in dark cloud L1174 with multi-wavelength data. Mapping observations of L1174 in $^{13}$CO $J=2-1$ and $^{12}$CO $J=3-2$ were performed using the KOSMA 3-meter telescope. Six molecular cores with masses ranging from 5 to 31 $M_\odot$ and sizes ranging from 0.17 to 0.39 pc are resolved. Large area ahead of a Herbig Be star, HD 200775, is in expanding and core 1 is with collapse signature. Large line widths of $^{13}$CO $J=2-1$ indicate the ubiquity of turbulent motions in this region. Spectra of $^{12}$CO $J=3-2$ prevalently show conspicuously asymmetric double-peaked profiles. In a large area, red-skewed profiles are detected and suggestive of a scenario of global expansion. There is a large cavity around the Herbig Be star HD 200775, the brightest star in L1174. The gas around the cavity has been severely compressed by the stellar winds from HD 200775. Feedbacks from HD 200775 may have helped form the molecular cores around the cavity. Seventeen 2MASS potential young stellar objects were identified according to their 2MASS colour indices. The spatial distribution of the these 2MASS sources indicates that some of them have a triggered origin. All these suggest that feedbacks from a Herbig Ae/Be star may also have the potential to trigger star forming activities.
description: 13 pages, 10 figures; Accepted for publication in MNRAS
An actor-critic algorithm with policy gradients to solve the job shop scheduling problem using deep double recurrent agents
Creators: name: Monaci, Marta
name: Agasucci, Valerio
name: Grani, Giorgio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 90-08

description: There is a growing interest in integrating machine learning techniques and optimization to solve challenging optimization problems. In this work, we propose a deep reinforcement learning methodology for the job shop scheduling problem (JSSP). The aim is to build up a greedy-like heuristic able to learn on some distribution of JSSP instances, different in the number of jobs and machines. The need for fast scheduling methods is well known, and it arises in many areas, from transportation to healthcare. We model the JSSP as a Markov Decision Process and then we exploit the efficacy of reinforcement learning to solve the problem. We adopt an actor-critic scheme, where the action taken by the agent is influenced by policy considerations on the state-value function. The procedures are adapted to take into account the challenging nature of JSSP, where the state and the action space change not only for every instance but also after each decision. To tackle the variability in the number of jobs and operations in the input, we modeled the agent using two incident LSTM models, a special type of deep neural network. Experiments show the algorithm reaches good solutions in a short time, proving that is possible to generate new greedy heuristics just from learning-based methodologies. Benchmarks have been generated in comparison with the commercial solver CPLEX. As expected, the model can generalize, to some extent, to larger problems or instances originated by a different distribution from the one used in training.
Vegetation and climate change at the southern margin of the Neo-Tethys during the Cenomanian (Late Cretaceous): Evidence from Egypt
Creators: name: El Atfy, Haytham
name: Coiffard, Clément
name: El Beialy, Salah Y. Y.
name: Uhl, Dieter
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: Paleoclimatology
subject: Flowering plants
subject: Egypt
subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften

description: Changes in terrestrial vegetation during the mid-Cretaceous and their link to climate and environmental change are poorly understood. In this study, we use plant macrofossils and analysis of fossil pollen and spores from the Western Desert, Egypt, to assess temporal changes in plant communities during the Cenomanian. The investigated strata have relatively diverse sporomorph assemblages, which reflect the nature of parent vegetation. Specifically, the palynofloras represent ferns, conifers, monosulcate pollen producers, Gnetales, and a diverse group of angiosperms. Comparisons of both, dispersed palynoflora and plant macrofossils reveal different characteristics of the palaeoflora owing to a plethora of taphonomical and ecological biases including the depositional environment, production levels, and discrepancies between different plant organs. A combination of detailed records of sporomorphs, leaves, and charcoal from the studied successions provide new understandings of the palaeoclimate and palaeogeography during the Cenomanian and Albian-Cenomanian transition in Egypt. The mixed composition of the palynofloral assemblages reflects the presence of different depositional situations with a weak marine influence, as evidenced by a minor dinoflagellate cysts component. The local vegetation comprised various categories including herbaceous groups including ferns and eudicots, fluvial, open environments, and xeric arboreal communities dominated by Cheirolepidiaceae and perhaps including drought- and/or salt-tolerating ferns (Anemiaceae) and other gymnosperms (Araucariaceae, Ginkgoales, Cycadales, and Gnetales) as well as angiosperms. The presence of riparian and freshwater wetland communities favouring aquatic and/or hygrophilous ferns (of Salviniaceae and Marsileaceae), is noted. The wide variation of depositional settings derived from the palynological data may be attributed to a prevalent occurrence of producers in local vegetation during the early Cenomanian of Egypt. For the purpose of this work on the studied Bahariya Formation and its equivalent rock units, where iconic dinosaurs and other fossil fauna roamed, we attempt to improve the understanding of Egypt’s Cenomanian climate, which is reconstructed as generally warm and humid punctuated by phases of considerably drier conditions of varying duration.
Scale-building in the party-state: the governance of China’s metropolitan regions
Creators: name: Dong, Lisheng
name: Kübler, Daniel
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Cell Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Sociology
subject: FOS: Sociology
subject: Developmental Biology
subject: Science Policy

description: This paper explores the emerging governance patterns in Chinese metropolitan regions (城市群 chengshiqun). In the scholarly debate on city-regional governance in the West, a prominent position holds that governing large urban regions entails a rescaling of state territories. In China, the central government plays a prominent role in the scale-building of China’s metropolitan regions. This is not only evident in the first stage of the post-reform policies, involving major reforms of state scales for the purpose of economic and urban development. Drawing on three case studies (the Yangtze River Delta, Guanzhong–Tianshui and Beijing–Tianjin–Hebei metropolitan regions), it is shown that the Chinese central government also plays a strong role in the current stage of metropolitan regional development. It is argued that the trajectory of metropolitan scale-building in China is a result of the hierarchical administrative system impeding horizontal cooperation between subnational entities of the party-state.
Phylogeny of Saxifraga section Saxifraga subsection Arachnoideae (Saxifragaceae) and the origin of low elevation shade-dwelling species
Creators: name: Gerschwitz-Eidt, Michael A.
name: Dillenberger, Markus S.
name: Kadereit, Joachim W.
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: adaptive evolution
subject: Alps
subject: Hybseq
subject: indicator values
subject: quaternary
subject: rear edge
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::570 Biowissenschaften; Biologie

description: Saxifraga section Saxifraga subsection Arachnoideae is a lineage of 12 species distributed mainly in the European Alps. It is unusual in terms of ecological diversification by containing both high elevation species from exposed alpine habitats and low elevation species from shady habitats such as overhanging rocks and cave entrances. Our aims are to explore which of these habitat types is ancestral, and to identify the possible drivers of this remarkable ecological diversification. Using a Hybseq DNA-sequencing approach and a complete species sample we reconstructed and dated the phylogeny of subsection Arachnoideae. Using Landolt indicator values, this phylogenetic tree was used for the reconstruction of the evolution of temperature, light and soil pH requirements in this lineage. Diversification of subsection Arachnoideae started in the late Pliocene and continued through the Pleistocene. Both diversification among and within clades was largely allopatric, and species from shady habitats with low light requirements are distributed in well-known refugia. We hypothesize that low light requirements evolved when species persisting in cold-stage refugia were forced into marginal habitats by more competitive warm-stage vegetation. While we do not claim that such competition resulted in speciation, it very likely resulted in adaptive evolution.
SymbioLCD: Ensemble-Based Loop Closure Detection using CNN-Extracted Objects and Visual Bag-of-Words
Creators: name: Kim, Jonathan J. Y.
name: Urschler, Martin
name: Riddle, Patricia J.
name: Wicker, Jörg S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Loop closure detection is an essential tool of Simultaneous Localization and Mapping (SLAM) to minimize drift in its localization. Many state-of-the-art loop closure detection (LCD) algorithms use visual Bag-of-Words (vBoW), which is robust against partial occlusions in a scene but cannot perceive the semantics or spatial relationships between feature points. CNN object extraction can address those issues, by providing semantic labels and spatial relationships between objects in a scene. Previous work has mainly focused on replacing vBoW with CNN-derived features. In this paper, we propose SymbioLCD, a novel ensemble-based LCD that utilizes both CNN-extracted objects and vBoW features for LCD candidate prediction. When used in tandem, the added elements of object semantics and spatial-awareness create a more robust and symbiotic loop closure detection system. The proposed SymbioLCD uses scale-invariant spatial and semantic matching, Hausdorff distance with temporal constraints, and a Random Forest that utilizes combined information from both CNN-extracted objects and vBoW features for predicting accurate loop closure candidates. Evaluation of the proposed method shows it outperforms other Machine Learning (ML) algorithms - such as SVM, Decision Tree and Neural Network, and demonstrates that there is a strong symbiosis between CNN-extracted object information and vBoW features which assists accurate LCD candidate prediction. Furthermore, it is able to perceive loop closure candidates earlier than state-of-the-art SLAM algorithms, utilizing added spatial and semantic information from CNN-extracted objects.
description: 7 pages. Accepted at 2021 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
The impact of thermodynamics on gravitational collapse: filament formation and magnetic field amplification
Creators: name: Peters, Thomas
name: Schleicher, Dominik R. G.
name: Klessen, Ralf S.
name: Banerjee, Robi
name: Federrath, Christoph
name: Smith, Rowan J.
name: Sur, Sharanya
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Stars form by the gravitational collapse of interstellar gas. The thermodynamic response of the gas can be characterized by an effective equation of state. It determines how gas heats up or cools as it gets compressed, and hence plays a key role in regulating the process of stellar birth on virtually all scales, ranging from individual star clusters up to the galaxy as a whole. We present a systematic study of the impact of thermodynamics on gravitational collapse in the context of high-redshift star formation, but argue that our findings are also relevant for present-day star formation in molecular clouds. We consider a polytropic equation of state, P = k rho^Gamma, with both sub-isothermal exponents Gamma < 1 and super-isothermal exponents Gamma > 1. We find significant differences between these two cases. For Gamma > 1, pressure gradients slow down the contraction and lead to the formation of a virialized, turbulent core. Weak magnetic fields are strongly tangled and efficiently amplified via the small-scale turbulent dynamo on timescales corresponding to the eddy-turnover time at the viscous scale. For Gamma < 1, on the other hand, pressure support is not sufficient for the formation of such a core. Gravitational contraction proceeds much more rapidly and the flow develops very strong shocks, creating a network of intersecting sheets and extended filaments. The resulting magnetic field lines are very coherent and exhibit a considerable degree of order. Nevertheless, even under these conditions we still find exponential growth of the magnetic energy density in the kinematic regime.
Increasing species richness along elevational gradients is associated with niche packing in bat assemblages
Creators: name: Chakravarty, Rohit
name: Radchuk, Viktoriia
name: Managave, Shreyas
name: Voigt, Christian C.
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: bats
subject: elevational gradients
subject: Himalaya
subject: niche expansion
subject: niche packing
subject: stable isotopes
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::570 Biowissenschaften; Biologie

description: 1. The change in species richness along elevational gradients is a well-known pattern in nature. Niche theory predicts that increasing species richness in assemblages can either lead to denser packing of niche space (‘niche packing’) or an expansion into its novel regions (‘niche expansion’). Traditionally, these scenarios have been studied using functional traits but stable isotopes provide advantages such as identifying the degree of resource specialisation, or niche partitioning among functionally similar species. 2. In this study, we evaluate the relevance of niche packing versus niche expansion by investigating stable carbon and nitrogen isotopic niche width and overlap among 23 bat species from six functional groups across a 1500 m elevational gradient in the Himalaya. 3. Our results suggest that an increase in species richness in the low elevation is accompanied by small niche width with high overlap, whereas the high elevation assemblage shows large niche width with low overlap among functional group members. At the functional group level, edge-space foraging, trawling, and active gleaning bats have the highest niche width while passive gleaning bats that are only found in high elevations are isotopic specialists showing low overlap with other groups. Edge and open-space foraging bats showed idiosyncratic changes in niche width across elevations. We also find that the niches of rhinolophid bats overlap with edge-space and open-space foraging bats despite their unique functional traits. 4. These results support the idea that at low elevations high species richness is associated with niche packing while at high elevations strong niche partitioning prevails in dynamic and resource-poor environments. We conclude that although high elevation animal assemblages are often ‘functionally underdispersed’, that is show homogenous functional traits, our approach based on stable isotopes demonstrates niche partitioning among such functionally similar species.