cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
SGN: Sparse Gauss-Newton for Accelerated Sensitivity Analysis
Creators: name: Zehnder, Jonas
name: Coros, Stelian
name: Thomaszewski, Bernhard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: I.2.8; J.6

description: We present a sparse Gauss-Newton solver for accelerated sensitivity analysis with applications to a wide range of equilibrium-constrained optimization problems. Dense Gauss-Newton solvers have shown promising convergence rates for inverse problems, but the cost of assembling and factorizing the associated matrices has so far been a major stumbling block. In this work, we show how the dense Gauss-Newton Hessian can be transformed into an equivalent sparse matrix that can be assembled and factorized much more efficiently. This leads to drastically reduced computation times for many inverse problems, which we demonstrate on a diverse set of examples. We furthermore show links between sensitivity analysis and nonlinear programming approaches based on Lagrange multipliers and prove equivalence under specific assumptions that apply for our problem setting.
description: 10 pages, 7 figures
$H^1$ and dyadic $H^1$
Creators: name: Treil, Sergei
Publisher: name: arXiv
Year: 2008
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: Primary 42B30, 42B20, Secondary 42B25

description: In this paper we give a simple proof of the fact that the average over all dyadic lattices of the dyadic $H^1$-norm of a function gives an equivalent $H^1$-norm. The proof we present works for both one-parameter and multi-parameter Hardy spaces. The results of such type are known. The first result (for one-parameter Hardy spces) belongs to Burgess Davis (1980). Also, by duality, such results are equivalent to the "BMO from dyadic BMO" statements proved by Garnett-Jones(1982} for one parameter case, and by Pipher-Ward (2008) for two-parameter case. While the paper generalizes these results to the multi-parameter setting, this is not its main goal. The purpose of the paper is to present an approach leading to a simple proof, which works in both one-parameter and multi-parameter cases. The main idea of treating square function as a Calderon--Zygmind operator is a commonplace in harmonic analysis; the main observation, on which the paper is based, is that one can treat the random dyadic square function this way. After that, all is proved by using the standard and well-known results about Calderon--Zygmind operators in the Hilbert-space-valued setting. As an added bonus, we get a simple proof of the (equivalent by duality) inclusion $\text{BMO}\subset \text{BMO}_d$, $H^1_d \subset H^1$ in the multi-parameter case. Note, that unlike the one-parameter case, the inclusions in the general situation are far from trivial.
description: 14 pages. In the new version a minor error was corrected, see p. 8, reasoning before Section 1.3. The correct smoothness exponent in the averaged square function is 1/2, not N/2 as it was stated in the earlier version
Cross-Correlation study between CMB lensing and galaxy surveys
Creators: name: Saraf, Chandra Shekhar
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Cosmic Microwave Background (CMB) is a powerful probe to study the early universe and various cosmological models. Weak gravitational lensing affects the CMB by changing its power spectrum, but meanwhile, it also carries information about the distribution of lensing mass and hence, the large scale structure (LSS) of the universe. When studies of the CMB is combined with the tracers of LSS, one can constrain cosmological models, models of LSS development and astrophysical parameters simultaneously. The main focus of this project is to study the cross-correlations between CMB lensing and the galaxy matter density to constrain the galaxy bias ($b$) and the amplitude scaling parameter ($A$), to test the validity of $Λ$CDM model. We test our approach for simulations of the Planck CMB convergence field and galaxy density field, which mimics the density field of the Herschel Extragalactic Legacy Project (HELP). We use maximum likelihood method to constrain the parameters.
description: 6 pages, 3 figures, published in Proceedings of the Polish Astronomical Society
Particle acceleration in the driven relativistic reconnection
Creators: name: Lyubarsky, Yuri
name: Liverts, Michael
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the compression driven magnetic reconnection in the relativistic electron-positron plasma. Making use of a 2.5D particle-in-cell code, we simulated compression of a magnetized plasma layer containing a current sheet within it. We found that the particle spectrum within the reconnecting sheet becomes non-thermal; it could be approximated by a power-law distribution with an index of -1 and an exponential cutoff.
description: 15 pages, 9 figures, to appear in the ApJ August 10, 2008, v683n 1 issue
Mediävistik und Frauengeschichte
Creators: name: Rath, Brigitte
name: Simon-Muscheid, Katharina
name: Hanawalt, Barbara
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 1993

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 4 Nr. 2 (1993): Arbeit und Herrschaft in der frühen Neuzeit
Erosion of a granular bed driven by laminar fluid flow
Creators: name: Lobkovsky, A. E.
name: Orpe, A. V.
name: Molloy, R.
name: Kudrolli, A.
name: Rothman, D. H.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $θ$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $θ>θ_c$. We find that the Shields criterion describes the observed relationship $h_r \propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $θ$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $θ- θ_c$ with exponent $1.75 \pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.
description: 12 pages, 5 figures
Jacques Le Goff, Geschichte und Gedächtnis, Frankfurt am Main u. New York: Campus Verlag 1992.
Creators: name: Mejstrik, Alexander
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 1993

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 4 Nr. 3 (1993): Klios Texte
Discs and outflows in the early phases of massive star formation: influence of magnetic fields and ambipolar diffusion
Creators: name: Commerçon, Benoît
name: González, Matthias
name: Mignon-Risse, Raphaël
name: Hennebelle, Patrick
name: Vaytet, Neil
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study mass accretion and ejection in the vicinity of massive star forming cores using high-resolution (5 au) 3D AMR numerical simulations. We investigate the mechanisms at the origin of outflows and characterise the properties of the disc forming around massive protostars. We include both protostellar radiative feedback via PMS evolutionary tracks and magnetic ambipolar diffusion. We studied 3 different cases: purely hydrodynamical, ideal MHD, and ambipolar diffusion. In the resistive models, we investigate the effects the initial amplitude of both magnetic field and rotation have on the properties of the massive protostellar system. We use simple criteria to identify the outflow and disc material and follow their evolution as the central star accretes mass up to 20 solar mass. The outflow is completely different when magnetic fields are introduced, so that magnetic processes are the main driver of the outflow up to stellar masses of ~20 solar mass. The disc properties depend on the physics included. The disc formed in the ideal and resistive runs show opposite properties in terms of plasma beta and of magnetic fields topology. While the disc in the ideal case is dominated by the magnetic pressure and the toroidal magnetic fields, the one formed in the resistive runs is dominated by the thermal pressure and has essentially vertical magnetic fields in the inner regions (R<200 au). We find that magnetic processes dominate the early evolution of massive protostellar systems (<20 solar mass) and shapes the accretion/ejection as well as the disc formation. Ambipolar diffusion is mainly at work at disc scales and regulates its properties. Our finding for the outflow and disc properties are reminiscent of low-mass star formation, suggesting that accretion and ejection in young massive and low-mass protostars are regulated by the same physical processes at the early stages.
description: 21 pages, 16 figures, accepted for publication in A&A
Velocity-selective sublevel resonance of atoms with an array of current-carrying wires
Creators: name: Hatakeyama, Atsushi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Resonance transitions between the Zeeman sublevels of optically-polarized Rb atoms traveling through a spatially periodic magnetic field are investigated in a radio-frequency (rf) range of sub-MHz. The atomic motion induces the resonance when the Zeeman splitting is equal to the frequency at which the moving atoms feel the magnetic field oscillating. Additional temporal oscillation of the spatially periodic field splits a motion-induced resonance peak into two by an amount of this oscillation frequency. At higher oscillation frequencies, it is more suitable to consider that the resonance is mainly driven by the temporal field oscillation, with its velocity-dependence or Doppler shift caused by the atomic motion through the periodic field. A theoretical description of motion-induced resonance is also given, with emphasis on the translational energy change associated with the internal transition.
description: 7 pages, 3 figures, final version
Compact groups from the Millennium Simulations: I. Their Nature and the completeness of the Hickson sample
Creators: name: Diaz-Gimenez, Eugenia
name: Mamon, Gary
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We identify compact groups of galaxies (CGs) within mock galaxy catalogues from the Millennium Simulation at z=0 with three semi-analytic models (SAMs) of galaxy formation. CGs are identified using the same 2D criteria as those visually applied by Hickson (1982) to his CGs (HCGs), but with a brightest galaxy magnitude limit, and the blending of close projected pairs. Half of the mock CGs identified in projection contain at least 4 accordant velocities (mvCGs), versus 70% for HCGs. In comparison to mvCGs, the HCGs are only 8% complete at distances < 9000 km/s, missing the CGs with small angular sizes, a strongly dominant galaxy, and (for one SAM) the CGs that are fainter and those with lower surface brightness. We explore different ways to determine the fraction of physically dense groups. Binding energy criteria turn out to be inapplicable given the segregation between galaxies and dark matter particles. We rely instead on the combination of the 3D length of the CGs (maximum real space galaxy separation) and their elongation along the line-of-sight (ratio of maximum line-of-sight to maximum projected separations), restricting ourselves in both cases to smallest quartets within the CGs. We find that between 64% and 80% (depending on the SAM) of the mvCGs have 3D lengths shorter than 200 kpc/h, between 71% and 80% have line-of-sight elongations less than 2, while between 59% and 76% have either 3D lengths shorter than 100 kpc/h or both lengths shorter than 200 kpc/h and elongations smaller than 2. Therefore, chance alignments (CAs) of galaxies concern at most 40% of the mvCGs. These CAs are mostly produced from larger host groups, but a few have galaxies extending a few Mpc beyond the host group. The mvCGs built with the Hickson selection with (without) the close projected pair blending criterion have 10% higher (lower) fractions of physically dense systems.
description: 19 pages, 10 figures. Accepted for publication in MNRAS. The new version has a different title and a different author list. The analysis of the nature of compact groups has been thoroughly modified, while the subsections on compact group properties and correlations have been omitted and should appear elsewhere
Iron-Containing Nitrogen-Doped Carbon Nanomaterials Prepared via NaCl Template as Efficient Electrocatalysts for the Oxygen Reduction Reaction
Creators: name: Juvanen, Silver
name: Sarapuu, Ave
name: Vlassov, Sergei
name: Kook, Mati
name: Kisand, Vambola
name: Käärik, Maike
name: Treshchalov, Alexey
name: Aruväli, Jaan
name: Kozlova, Jekaterina
name: Tamm, Aile
name: Leis, Jaan
name: Tammeveski, Kaido
Publisher: name: Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
Year: 2022
Subjects: electrocatalysis
electrochemistry
oxygen reduction
non-precious metal catalyst

description: The dataset contains the data presented in the figures of published paper: "Iron-Containing Nitrogen-Doped Carbon Nanomaterials Prepared via NaCl Template as Efficient Electrocatalysts for Oxygen Reduction Reaction", ChemElectroChem 8 (2021) 2288-2297 (https://doi.org/10.1002/celc.202100571)
An open question: Are topological arguments helpful in setting initial conditions for transport problems and quantization criteria/ quantum computing for Density Wave physics?
Creators: name: Beckwith, A. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: We present derived I-E curves that match Zenier curves used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. The open question is whether the coefficients picked in both the wavefunctionals and the magnitude of the coefficients of the driven sine Gordon physical system should be picked by topological charge arguments that in principle appear to assign values that have a tie in with the false vacuum hypothesis first presented by Sidney Coleman. Our supposition is that indeed this is useful and that the topological arguments give evidence as to a first order phase transition which gives credence to the observed and calculated I-E curve as evidence of a quantum switching phenomena in density wave physics, one which we think with further development would have applications to quantum computing, via quantum coherent phase evolution, as outlined in this paper . This analysis is enhanced by a new phi to the fourth power field theory treatment of how to model field theory in real time evolution as given to the Author by Dr. Fred Cooper as part of a meeting in KITP, UCSB in early 2008
description: 12 pages, 6 figures. Contents of accepted poster for the 6th international conference on High Tc super conductivity, "stripes08" to be held in Erice, Sicily, Italy July 26 to August 1, 2008
title: Front Matter, Table of Contents, Preface, Conference Organization
Creators: name: Klin, Bartek
name: Lasota, Sławomir
name: Muscholl, Anca
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2022
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Conference Organization
subject: Theory of computation → Concurrency

description: Front Matter, Table of Contents, Preface, Conference Organization
description: LIPIcs, Vol. 243, 33rd International Conference on Concurrency Theory (CONCUR 2022), pages 0:i-0:x
Stipe Mesic, Kako smo srušili Jugoslaviju. Politički memoari posljednjeg Predsjednika Predsjedništva SFRJ [Wie wir Jugoslawien zerstörten. Politische Memoiren des letzten Vorsitzenden des Präsidiums der Sozialistischen Föderativen Republik Jugos
Creators: name: Promitzer, Christian
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 1994

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 5 Nr. 1 (1994): Das Fremde vernichten
Specific Features of Phase States of a Diluted 2D Magnet with Frustration
Creators: name: Yasinskaya, D. N.
name: Ulitko, V. A.
name: Panov, Yu. D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The properties of a dilute Ising magnet are studied using a two-dimensional spin-pseudospin model with charged impurities and a frustration caused by the competition of the charge and magnetic orderings. Based on the classical Monte Carlo method, the ground state phase diagram has been obtained and also unusual phase states appeared at finite temperatures have been studied. The regions in which order-order phase transitions and also reentrant phase transition are observed have been found.
description: 11 pages, 6 figures
Semiclassical Unimodular Gravity
Creators: name: Fiol, Bartomeu
name: Garriga, Jaume
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Classically, unimodular gravity is known to be equivalent to General Relativity (GR), except for the fact that the effective cosmological constant $Λ$ has the status of an integration constant. Here, we explore various formulations of unimodular gravity beyond the classical limit. We first consider the non-generally covariant action formulation in which the determinant of the metric is held fixed to unity. We argue that the corresponding quantum theory is also equivalent to General Relativity for localized perturbative processes which take place in generic backgrounds of infinite volume (such as asymptotically flat spacetimes). Next, using the same action, we calculate semiclassical non-perturbative quantities, which we expect will be dominated by Euclidean instanton solutions. We derive the entropy/area ratio for cosmological and black hole horizons, finding agreement with GR for solutions in backgrounds of infinite volume, but disagreement for backgrounds with finite volume. In deriving the above results, the path integral is taken over histories with fixed 4-volume. We point out that the results are different if we allow the 4-volume of the different histories to vary over a continuum range. In this "generalized" version of unimodular gravity, one recovers the full set of Einstein's equations in the classical limit, including the trace, so $Λ$ is no longer an integration constant. Finally, we consider the generally covariant theory due to Henneaux and Teitelboim, which is classically equivalent to unimodular gravity. In this case, the standard semiclassical GR results are recovered provided that the boundary term in the Euclidean action is chosen appropriately.
description: Substantially revised version, with new results and added discussion
Inverse currents in Coulomb-coupled quantum dots
Creators: name: Zhang, Yanchao
name: Xie, Zhenzhen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The inverse current, i.e., induced current is opposite to applied force, has recentlybeen found in a classical one-dimensional interacting Hamiltonian system [Phys. Rev.Lett. 124, 110607 (2020)]. In this paper, we show that inverse current also exists in quantum system. Based on Coulomb-coupled quantum dots system, we find that inverse current will appear when Coulomb interaction increases. This does not violate the second law of thermodynamics, since entropy reduction caused by inverse current is compensated by entropy increase caused by forward current, which ensure that total entropy increase of the system is always greater than zero.
A Unified Theory for the Cuprates, Iron-Based and Similar Superconducting Systems: Application for Spin and Charge Excitations in the Hole-Doped Cuprates
Creators: name: Ashkenazi, J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A unified theory for the cuprates and the iron-based superconductors is derived on the basis of common features in their electronic structures including quasi-two-dimensionality, and the large-U nature of the electron orbitals close to E_F (smaller-U hybridized orbitals reside at bonding and antibonding states away from E_F). Consequently, low-energy excitations are described in terms of auxiliary particles, representing combinations of atomic-like electron configurations, rather than electron-like quasiparticles. The introduction of a Lagrange Bose field is necessary to enable the treatments of these auxiliary particles as bosons or fermions. The condensation of the bosons results in static or dynamical inhomogeneities, and consequently in a commensurate or an incommensurate resonance mode. The dynamics of the fermions determines the charge transport, and their strong coupling to the Lagrange-field bosons results in pairing and superconductivity. The calculated resonance mode in hole-doped cuprates agrees with the experimental results, and is shown to be correlated with the pairing gap on the Fermi arcs.
description: 8 pages, 4 figures
The similarity of the interstellar comet 2I/Borisov to solar system comets from high resolution optical spectroscopy
Creators: name: Opitom, C.
name: Jehin, E.
name: Hutsemékers, D.
name: Shinnaka, Y.
name: Manfroid, J.
name: Rousselot, P.
name: Raghuram, S.
name: Kawakita, H.
name: Fitzsimmons, A.
name: Meech, K.
name: Micheli, M.
name: Snodgrass, C.
name: Yang, B.
name: Hainaut, O.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: 2I/Borisov - hereafter 2I - is the first visibly active interstellar comet observed in the solar system, allowing us for the first time to sample the composition of a building block from another system. We report on the monitoring of 2I with UVES, the high resolution optical spectrograph of the ESO Very Large Telescope at Paranal, during four months from November 15, 2019 to March 16, 2020. Our goal is to characterize the activity and composition of 2I with respect to solar system comets. We collected high resolution spectra at 12 different epochs from 2.1 au pre-perihelion to 2.6 au post perihelion. On December 24 and 26, 2019, close to perihelion, we detected several OH lines of the 309 nm (0-0) band and derived a water production rate of $2.2\pm0.2 \times 10^{26}$ molecules/s. The three [OI] forbidden oxygen lines were detected at different epochs and we derive a green-to-red doublet intensity ratio (G/R) of $0.31\pm0.05$ close to perihelion. NH$_2$ ortho and para lines from various bands were measured and allowed us to derive an ortho-to-para ratio (OPR) of $3.21\pm0.15$, corresponding to an OPR and spin temperature of ammonia of $1.11\pm0.08$ and $31^{+10}_{-5}$ K, respectively. These values are consistent with the values usually measured for solar system comets. Emission lines of the radicals NH (336 nm), CN (388 nm), CH (431 nm), and C$_2$ (517 nm) were also detected. Several FeI and NiI lines were identified and their intensities were measured to provide a ratio of log (NiI/FeI) = $0.21\pm0.18$ in agreement with the value recently found in solar system comets. Our high spectral resolution observations of 2I/Borisov and the associated measurements of the NH$_2$ OPR and the Ni/Fe abundance ratio are remarkably similar to solar system comets. Only the G/R ratio is unusually high but consistent with the high abundance ratio of CO/H$_2$O found by other investigators.
description: Accepted for publication in A&A
Historiographischer Optimismus
Creators: name: Aly, Götz
name: Lausecker, Werner
name: Müller, Albert
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 1999

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 10 Nr. 1 (1999): Hochschulen im Nationalsozialismus
Cellular Systems with Full-Duplex Compress-and-Forward Relaying and Cooperative Base Stations
Creators: name: Somekh, Oren
name: Simeone, Osvaldo
name: Poor, H. Vincent
name: Shamai, Shlomo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this paper the advantages provided by multicell processing of signals transmitted by mobile terminals (MTs) which are received via dedicated relay terminals (RTs) are studied. It is assumed that each RT is capable of full-duplex operation and receives the transmission of adjacent relay terminals. Focusing on intra-cell TDMA and non-fading channels, a simplified relay-aided uplink cellular model based on a model introduced by Wyner is considered. Assuming a nomadic application in which the RTs are oblivious to the MTs' codebooks, a form of distributed compress-and-forward (CF) scheme with decoder side information is employed. The per-cell sum-rate of the CF scheme is derived and is given as a solution of a simple fixed point equation. This achievable rate reveals that the CF scheme is able to completely eliminate the inter-relay interference, and it approaches a ``cut-set-like'' upper bound for strong RTs transmission power. The CF rate is also shown to surpass the rate of an amplify-and-forward scheme via numerical calculations for a wide range of the system parameters.
description: Proceedings of the 2008 IEEE International Symposium on Information Theory, Toronto, ON, Canada, July 6 - 11, 2008
The colorful Helly theorem and colorful resolutions of ideals
Creators: name: Floystad, Gunnar
Publisher: name: arXiv
Year: 2008
Subjects: subject: Commutative Algebra (math.AC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 13D02

description: We demonstrate that the topological Helly theorem and the algebraic Auslander-Buchsbaum may be viewed as different versions of the same phenomenon. Using this correspondence we show how the colorful Helly theorem of I.Barany and its generalizations by G.Kalai and R.Meshulam translates to the algebraic side. Our main results are algebraic generalizations of these translations, which in particular gives a syzygetic version of Hellys theorem.
description: 13 pages, minor changes
Beyond the dips of V807 Tau, a spectropolarimetric study of a dipper s magnetosphere
Creators: name: Pouilly, Kim
name: Bouvier, Jérôme
name: Alecian, Evelyne
name: Alencar, Silvia H. P.
name: Cody, Ann-Marie
name: Donati, Jean-François
name: Grankin, Konstantin
name: Rebull, Luisa
name: Folsom, Colin P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We aim to characterize the magnetospheric accretion process in the young stellar object V807 Tau, one of the most stable dippers revealed by K2 in the Taurus star forming region. We performed photometric and spectropolarimetric follow-up observations of this system with CFHT/ESPaDOnS in order to investigate its variability over several rotational periods. We derive a 4.38 day period from the K2 light curve. This period is also seen in the radial velocity variations, ascribed to spot modulation. The narrow component of the He I 5876 Å line as well as the red wing of the Hβ and Hγ line profiles also vary in intensity with the same periodicity. The former traces the accretion shock at the stellar surface, and the latter is a signature of an accretion funnel flow crossing the line of sight. We derive a surface brightness and magnetic field topology from the modeling of Stokes I and V profiles, respectively, for photospheric lines and for the He I line. This reveals a bright spot at the stellar surface, located at a latitude of 60 deg, and a maximum field strength of about 2 kG. The magnetic field topology at the stellar surface is dominated by a dipolar component inclined by about 40 deg onto the spin axis. Despite of its clear and stable dipper behavior, we derive a relatively low inclination of about 50 deg for this system, which calls question the origin of the dips. This low inclination is also consistent with the absence of deep inverse P Cygni components in the line profiles. We conclude that magnetospheric accretion is ongoing in V807 Tau, taking place through non-axisymmetric accretion funnel flows controlled by a strong, tilted, and mainly dipolar magnetic topology. Whether an inner disk warp resulting from this process can account for the dipper character of this source remains to be seen, given the low inclination of the system.
description: 18 pages, 23 figures, accepted in A&A
The volume conjecture for augmented knotted trivalent graphs
Creators: name: van der Veen, Roland
Publisher: name: arXiv
Year: 2008
Subjects: subject: Geometric Topology (math.GT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 57M25, 57M27

description: We propose to generalize the volume conjecture to knotted trivalent graphs and we prove the conjecture for all augmented knotted trivalent graphs. As a corollary we find that for any link L there is a link containing L for which the volume conjecture holds.
description: 28 pages, 14 figures Corrected typos, added corollary about arithmeticity
Functional properties of modified oilseed protein concentrates and isolates
Creators: name: Jones, Linda Jean
Publisher: name: University of British Columbia
Year: 2010

description: Compositional, structural and functional properties of nine oilseed concentrates and isolates were evaluated and compared. Three product sources, canola (rapeseed), sunflower and soybean were investigated, each treated during processing by enzyme-hydrolysis or linoleic acid addition, or left untreated as controls. Protein, carbohydrate and moisture contents of the products were measured, and examination of the gross structure of 10% aqueous dispersions was carried out using light microscopy techniques. Several functionality tests were performed, including determinations of water holding and water hydration capacities, protein solubility, steady shear flow behavior and viscoelasticity. Scanning electron microscopy was used to examine the microstructure of the gel-like materials produced when 10% aqueous dispersions of the products were heated in a boiling water bath. Both trypsin and linoleate treatment were observed to significantly affect the structural and functional properties of the products, although the treatment effects differed among sources in some cases. In general, trypsin-treated products contained smaller particles in dispersion, formed weaker gels on heating and exhibited higher solubility and water hydration capacities, and lower apparent viscosities in 10% dispersion. A trend toward larger particles in linoleate-treated product dispersions was observed along with stronger gel-forming abilities, increased solubilities, water hydration capacities and apparent viscosities in 10% dispersion. Simple correlation coefficients between several measured functional and compositional variables were computed to identify relationships among the physico-chemical properties. Both the size of the dispersed phase particles and the degree of interaction of the protein and carbohydrate components with water were determined to be important in governing functional properties.
Remote sensing of off-road vehicle impacts to soil and vegetation on the Lac du Bois rangelands, Kamloops, British Columbia
Creators: name: Allan, Grant Edward
Publisher: name: University of British Columbia
Year: 2010

description: Land use management to provide areas for off-road vehicle (ORV) recreational activity, and to control and reduce the ORV impacts, requires information on the rapidly changing conditions. The objective of this study was to develop a remote sensing method to monitor ORV impacts to soil and vegetation on the open lands of British Columbia. To complement available aerial photographs of the Lac du Bois range-land study area for 1971, 1975 and 1977, two scales and formats of aerial photographs were flown in the summer of 1979. A ground survey program was designed to support the aerial photograph interpretation of ORV impacts. The ORV trails, which were mapped from the aerial photographs, had an increase in bulk density and a decrease in moisture content and organic carbon. Regression analysis of the soil variables versus optical density values from the 1979 aerial photographs failed to provide consistent results to permit the identification of variations in soil conditions within areas of ORV activity. The monitoring program was developed as a multistage remote sensing approach. The first stage utilizes large scale (1:4000) aerial photographs to map and measure ORV trails and associated zones of secondary disturbance within a study area. The second stage utilizes very large scale (1:600) aerial photographs to sample the study area and assess the erosion conditions. The third stage collects ground information to assist the aerial photograph interpretation of the first two stages and to provide quantitative measures of the changes to selected soil and vegetation variables. To consolidate the monitoring program information, an ORV impact condition scale was developed. The simple five point scale summarizes the varying impact conditions within a study area and can be used to assess general changes over time within land management units.
Entropy Function and AdS(2)/CFT(1) Correspondence
Creators: name: Sen, Ashoke
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Wald's formula for black hole entropy, applied to extremal black holes, leads to the entropy function formalism. We manipulate the entropy computed this way to express it as the logarithm of the ground state degeneracy of a dual quantum mechanical system. This provides a natural definition of the extremal black hole entropy in the full quantum theory. Our analysis also clarifies the relationship between the entropy function formalism and the Euclidean action formalism.
description: LaTeX file, 13 pages; v2: expanded discussion, references added; v3: modified and expanded discussion, references added; v4: added extensive discussion on boundary conditions
,You got your history, I got mine'
Creators: name: Lorenz, Chris
Publisher: name: Austrian Journal of Historical Studies
Year: 1999

description: The author offers a critical appraisal of some central problems of post-modern historiography. Starting from Keith Jenkins's introduction to his postmodern history reader and referring to authors such as Michel Foucault, Hayden White and Michel de Certeau, Lorenz once again raises the question whether history/ies can be true or objective. Distancing himself decidedly from all trivialising forms of the receptions of postmodern thought, but at the same time remaining sceptical towards the likes of Foucault, de Certeau and White, Lorenz tries to formulate the basic outlines of those conditions, which might allow us to answer the initial question in the positive. His polemical and pointed essay is crowned by a discussion of the relationship between history and the instrumentality and legitimacy of power.
description: Austrian Journal of Historical Studies, Bd. 10 Nr. 4 (1999): sprache macht geschichte
Chemical abundances in Seyfert galaxies -- VIII. Argon abundance estimates
Creators: name: Monteiro, A. F.
name: Dors, O. L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: For the first time, the argon abundance relative to hydrogen abundance (Ar/H) in the narrow line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow emission line intensities of a sample of 64 local Seyfert 2 nuclei (z < 0.25) taken from Sloan Digital Sky Survey DR7 and measured by the MPA/JHU group were considered. We adopted the Te-method for AGNs, which is based on direct determination of the electron temperature, together with a grid of photoionization model results, built with the Cloudy code, to obtain a method for the derivation of the Ar/H abundance. We find that for a metallicity range of 0.2 < (Z/Zsolar) < 2.0, Seyfert 2 nuclei present Ar/H abundance ranging from 0.1 to 3 times the argon solar value, adopting log(O/H)=-3.31 and log(Ar/H)=-5.60. These range of values correspond to 8.0 < 12+log(O/H)< 9.0 and 5.4 < 12+log(Ar/H)< 6.9, respectively. The range of Ar/H and Ar/O abundance values obtained from our sample are in consonance with estimations from extrapolations of the radial abundance gradients to the central parts of the disk for four spiral galaxies. We combined our abundance results with estimates obtained from a sample of Hii galaxies, which were taken from the literature, and found that the Ar/O abundance ratio decreases slightly as the O/H abundance increases.
description: Accepted for publication by MNRAS
Thomas Bernhards literarische Auseinandersetzung mit dem Nationalsozialismus
Creators: name: Kreuzwieser, Markus
Publisher: name: Österreichische Zeitschrift für Geschichtswissenschaften
Year: 1999

description: Österreichische Zeitschrift für Geschichtswissenschaften, Bd. 10 Nr. 4 (1999): sprache macht geschichte
O Construtivismo na Ciência e na Educação Científica - SLIDES
Creators: name: Valadares, Jorge
Publisher: name: Zenodo
Year: 2006
Subjects: Construtivismo
Construtivismo humano

description: Este Seminário foi organizado pelo CECME – Centro de Estudos para as Ciências e Matemáticas no Ensino, da Universidade Aberta. Nele foi realçada a importância do construtivismo na educação actual e foi feita uma análise crítica comparativa das suas diversas formas.

No que respeita à epistemologia da ciência, mostra-se como ela é uma construção humana que tem subjacente uma forma de construtivismo superadora das grandes antíteses históricas acerca da origem, essência e validade do conhecimento.

É apresentado um instrumento construtivista, o Vê epistemológico de Gowin e mostra-se como ele responde à forma como foi construída a Teoria da Relatividade de Einstein.
Grid Connected Doubly Fed Induction Generator Based Wind Turbine under LVRT
Creators: name: Subramanian, Chandrasekaran <1983>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2014
Subjects: ING-IND/32 Convertitori, macchine e azionamenti elettrici

description: This project concentrates on the Low Voltage Ride Through (LVRT) capability of Doubly Fed Induction Generator (DFIG) wind turbine. The main attention in the project is, therefore, drawn to the control of the DFIG wind turbine and of its power converter and to the ability to protect itself without disconnection during grid faults. It provides also an overview on the interaction between variable speed DFIG wind turbines and the power system subjected to disturbances, such as short circuit faults. The dynamic model of DFIG wind turbine includes models for both mechanical components as well as for all electrical components, controllers and for the protection device of DFIG necessary during grid faults. The viewpoint of this project is to carry out different simulations to provide insight and understanding of the grid fault impact on both DFIG wind turbines and on the power system itself. The dynamic behavior of DFIG wind turbines during grid faults is simulated and assessed by using a transmission power system generic model developed and delivered by Transmission System Operator in the power system simulation toolbox Digsilent, Matlab/Simulink and PLECS.
Locally connected models for Julia sets
Creators: name: Blokh, A.
name: Curry, C.
name: Oversteegen, L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Dynamical Systems (math.DS)
subject: General Topology (math.GN)
subject: FOS: Mathematics
subject: 37F10 (Primary), 37B45, 37C25, 37F20, 37F50, 54F15 (Secondary)

description: Let $P$ be a polynomial with a connected Julia set $J$. We use continuum theory to show that it admits a \emph{finest monotone map $\ph$ onto a locally connected continuum $J_{\sim_P}$}, i.e. a monotone map $\ph:J\to J_{\sim_P}$ such that for any other monotone map $ψ:J\to J'$ there exists a monotone map $h$ with $ψ=h\circ \ph$. Then we extend $\ph$ onto the complex plane $\C$ (keeping the same notation) and show that $\ph$ monotonically semiconjugates $P|_{\C}$ to a \emph{topological polynomial $g:\C\to \C$}. If $P$ does not have Siegel or Cremer periodic points this gives an alternative proof of Kiwi's fundamental results on locally connected models of dynamics on the Julia sets, but the results hold for all polynomials with connected Julia sets. We also give a criterion and a useful sufficient condition for the map $\ph$ not to collapse $J$ into a point.
description: 54 pages, 1 diagram, 3 figures; the new version amends some of the proofs
Additional file 1 of Efficacy and safety of direct-acting antiviral regimen for patients with hepatitis C virus genotype 2: a systematic review and meta-analysis
Creators: name: Lei, Pek Kei
name: Liu, Zicheng
name: Ung, Carolina Oi Lam
name: Hu, Hao
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Pharmacology
subject: Immunology
subject: FOS: Clinical medicine
subject: Mathematical Sciences not elsewhere classified
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Supplementary Material 1
Earthquake forecasting and seismic hazard analysis: some insights on the testing phase and the modeling
Creators: name: Taroni, Matteo <1984>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2014
Subjects: GEO/10 Geofisica della terra solida

description: This thesis is divided in three chapters.  In the first chapter we analyse the results of the world forecasting experiment run by the Collaboratory for the Study of Earthquake Predictability (CSEP). We take the opportunity of this experiment to contribute to the definition of a more robust and reliable statistical procedure to evaluate earthquake forecasting models. We first present the models and the target earthquakes to be forecast. Then we explain the consistency and comparison tests that are used in CSEP experiments to evaluate the performance of the models. Introducing a methodology to create ensemble forecasting models, we show that models, when properly combined, are almost always better performing that any single model.
In the second chapter we discuss in depth one of the basic features of PSHA: the declustering of the seismicity rates. We first introduce the Cornell-McGuire method for PSHA and we present the different motivations that stand behind the need of declustering seismic catalogs. Using a theorem of the modern probability (Le Cam's theorem) we show that the declustering is not necessary to obtain a Poissonian behaviour of the exceedances that is usually considered fundamental to transform exceedance rates in exceedance probabilities in the PSHA framework. We present a method to correct PSHA for declustering, building a more realistic PSHA.
In the last chapter we explore the methods that are commonly used to take into account the epistemic uncertainty in PSHA. The most widely used method is the logic tree that stands at the basis of the most advanced seismic hazard maps. We illustrate the probabilistic structure of the logic tree, and then we show that this structure is not adequate to describe the epistemic uncertainty. We then propose a new probabilistic framework based on the ensemble modelling that properly accounts for epistemic uncertainties in PSHA.
Cooperation and competition between pair and multi-player social games in spatial populations
Creators: name: Szolnoki, Attila
name: Chen, Xiaojie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computer Science and Game Theory (cs.GT)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: The conflict between individual and collective interests is in the heart of every social dilemmas established by evolutionary game theory. We cannot avoid these conflicts but sometimes we may choose which interaction framework to use as a battlefield. For instance some people like to be part of a larger group while other persons prefer to interact in a more personalized, individual way. Both attitudes can be formulated via appropriately chosen traditional games. In particular, the prisoner's dilemma game is based on pair interaction while the public goods game represents multi-point interactions of group members. To reveal the possible advantage of a certain attitude we extend these models by allowing players not simply to change their strategies but also let them to vary their attitudes for a higher individual income. We show that both attitudes could be the winner at a specific parameter value. Interestingly, however, the subtle interplay between different states may result in a counterintuitive evolutionary outcome where the increase of the multiplication factor of public goods game drives the population to a fully defector state. We point out that the accompanying pattern formation can only be understood via the multipoint or multi-player interactions of different microscopic states where the vicinity of a particular state may influence the relation of two other competitors.
description: 18 pages, preprint format, 6 figures, accepted for publication in Sci. Rep
Theoretical Limits on Errors and Acquisition Rates in Localizing Switchable Fluorophores
Creators: name: Small, Alexander R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: A variety of recent imaging techniques are able to beat the diffraction limit in fluorescence microcopy by activating and localizing subsets of the fluorescent molecules in the specimen, and repeating this process until all of the molecules have been imaged. In these techniques there is a tradeoff between speed (activating more molecules per imaging cycle) and error rates (activating more molecules risks producing overlapping images that hide information on molecular positions), and so intelligent image-processing approaches are needed to identify and reject overlapping images. We introduce here a formalism for defining error rates, derive a general relationship between error rates, image acquisition rates, and the performance characteristics of the image processing algorithms, and show that there is a minimum acquisition time irrespective of algorithm performance. We also consider algorithms that can infer molecular positions from images of overlapping blurs, and derive the dependence of the minimimum acquisition time on algorithm performance.
description: 3 pages, 2 figures, 1 table Updated to show published version with minor revisions