cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Multi-Task Deep Learning Framework for Building Footprint Segmentation
Creators: name: Ekim, Burak
name: Sertel, Elif
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The task of building footprint segmentation has been well-studied in the context of remote sensing (RS) as it provides valuable information in many aspects, however, difficulties brought by the nature of RS images such as variations in the spatial arrangements and in-consistent constructional patterns require studying further, since it often causes poorly classified segmentation maps. We address this need by designing a joint optimization scheme for the task of building footprint delineation and introducing two auxiliary tasks; image reconstruction and building footprint boundary segmentation with the intent to reveal the common underlying structure to advance the classification accuracy of a single task model under the favor of auxiliary tasks. In particular, we propose a deep multi-task learning (MTL) based unified fully convolutional framework which operates in an end-to-end manner by making use of joint loss function with learnable loss weights considering the homoscedastic uncertainty of each task loss. Experimental results conducted on the SpaceNet6 dataset demonstrate the potential of the proposed MTL framework as it improves the classification accuracy considerably compared to single-task and lesser compounded tasks.
description: International Geoscience and Remote Sensing Symposium (IGARSS), Jul 2021, Brussels, Belgium
Investigation new positions for catalytic activity of Chaetomium thermophilum and Ceriporiopsis subvermispora formate dehydrogenases
Creators: name: Koçdemir, Kübra
name: Şen, Fatma
name: Wedajo, Yasin Adem
name: Bilgici, Muazzez Çağla
name: Bayram, Mustafa
name: Selçuk, İlke
name: Yılmazer, Berin
name: Çakar, Mehmet Mervan
name: Aslan, Elif Sibel
name: Binay, Barış
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biochemistry
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences

description: NAD+-dependent formate dehydrogenases (FDHs, E.C 1.2.1.2) catalyse the reversible reaction of CO2 to formate ion (HCOO−) and reduces NAD+ molecule to NADH. Previously described FDHs from Chaetomium thermophilum (CtFDH) and Ceriporiopsis subvermispora (CsFDH) are active against formate and HCO3–. In this study, we examined the functional effects of active site mutations in Ct and Cs NAD+-dependent FDHs. The residues Ile94, Asn120, Val310, His312 at CtFDH and Asn312, Val313, Val331 at CsFDH are located in the active site. The effects of amino acid changes on catalytic properties and thermal stability of CtFDH and CsFDH revealed some interesting results compared with structurally equivalent positions that have been studied in the literature. The strongest effect was observed in CsFDH Val313Pro against HCO3–. The KM value of the CsFDH Val313 enzyme for HCO3– substrate dramatically decreased, and enzyme activity increased. In CtFDH mutants, all enzymes except Val310Asn showed an increased kcat value when KM values increase. Analyses of results of mutant CtFDHs and CsFDHs give some promising results for CO2 reduction as compared to the literature. Structural analyses of the substrate-binding site were done by homology modelling.
Sum Rule for the ADM Mass and Tensions in Planar AdS Spacetimes
Creators: name: El-Menoufi, Basem Mahmoud
name: Ett, Benjamin
name: Kastor, David
name: Traschen, Jennie
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: An asymptotically planar AdS spacetimes is characterized by its ADM mass and tensions. We define an additional ADM charge Q associated with the scaling Killing vector of AdS, show that Q is given by a certain sum over the ADM mass and tensions and that Q vanishes on solutions to the Einstein equation with negative cosmological constant. The sum rule for the mass and tensions thus established corresponds in an AdS/CFT context to the vanishing of the trace of the boundary stress tensor. We also show that an analogous sum rule holds for local planar sources of stress-energy sources in AdS. In a simple model consisting of a static, plane symmetric source we find that the perturbative stress-energy tensor must be tracefree.
description: 15 pages; v2 minor changes
Dual communities in spatial networks
Creators: name: Kaiser, Franz
name: Böttcher, Philipp C.
name: Ronellenfitsch, Henrik
name: Latora, Vito
name: Witthaut, Dirk
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Both human-made and natural supply systems, such as power grids and leaf venation networks, are built to operate reliably under changing external conditions. Many of these spatial networks exhibit community structures. Here, we show that a relatively strong connectivity between the parts of a network can be used to define a different class of communities: dual communities. We demonstrate that traditional and dual communities emerge naturally as two different phases of optimized network structures that are shaped by fluctuations and that they suppress failure spreading, which underlines their importance in understanding the shape of real-world supply networks.
A Bake-Off Between CMFGEN and FASTWIND: Modeling the Physical Properties of SMC and LMC O-type Stars
Creators: name: Massey, Philip
name: Neugent, Kathryn F.
name: Hillier, D. John
name: Puls, Joachim
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The model atmosphere programs FASTWIND and CMFGEN are both elegantly designed to perform non-LTE analyses of the spectra of hot massive stars, and include sphericity and mass-loss. The two codes differ primarily in their approach towards line blanketing, with CMFGEN treating all of the lines in the co-moving frame and FASTWIND taking an approximate approach which speeds up execution times considerably. Although both have been extensively used to model the spectra of O-type stars, no studies have used the codes to independently model the same spectra of the same stars and compare the derived physical properties. We perform this task on ten O-type stars in the Magellanic Clouds. For the late-type O supergiants, both CMFGEN and FASTWIND have trouble fitting some of the He I lines, and we discuss causes and cures. We find that there is no difference in the average effective temperatures found by the two codes for the stars in our sample, although the dispersion is large, due primarily to the various difficulties each code has with He I. The surface gravities determined using FASTWIND are systematically lower by 0.12 dex compared to CMFGEN, a result we attribute to the better treatment of electron scattering by CMFGEN. This has implications for the interpretation of the origin of the so-called mass discrepancy, as the masses derived by FASTWIND are on average lower than inferred from stellar evolutionary models, while those found by CMFGEN are in better agreement.
description: Accepted by the Astrophysical Journal
Orderings of ultrafilters on Boolean algebras
Creators: name: Brendle, Jörg
name: Parente, Francesco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics

description: We study two generalizations of the Rudin-Keisler ordering to ultrafilters on complete Boolean algebras. To highlight the difference between them, we develop new techniques to construct incomparable ultrafilters in this setting. Furthermore, we discuss the relation with Tukey reducibility and prove that, assuming the Continuum Hypothesis, there exist ultrafilters on the Cohen algebra which are RK-equivalent in the generalized sense but Tukey-incomparable, in stark contrast with the classical setting.
Ultra-diluted gas transmittance revisited
Creators: name: Ratajczak, Jakub Marek
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The paper analyzes a model of optical transmittance of ultra-diluted gas, considering gas particles' non-locality and the quantum effect of their wave function spreading derived from solving the Schrödinger equation for a free particle. The analysis does not depend on a particular form of the wave function, but it assumes the reality of wave function. Among others, we show conserved mass gas clouds may become significantly more transparent than predicted by classic transmittance laws. This unexpected phenomenon is possible because mass conservation is governed by the sum of probabilities, while the Markov chain's product of probabilities controls the transmittance. Furthermore, we analytically derive the upper limit the closed system transmittance may grow and demonstrate a boundless, open gas cloud transmittance may grow up to 100%. Finally, we show the impact on interpretations of quantum mechanics. The model is naturally applicable in deep space conditions, where the environment is sparse. Furthermore, the model responds to dark matter requirements.
description: Rev. September 2022, 12 pages, 6 figures
Mean-field optical bistability of two-level atoms in structured reservoirs
Creators: name: Prataviera, G. A.
name: Yoshida, A. C.
name: Mizrahi, S. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider N driven two-level atoms interacting with a structured reservoir. By dressing the collective operators within a semiclassical approach, we derive a master equation and a mean-field single particle effective Hamiltonian. This Hamiltonian describes the optical bistability phenomenon occurring in the relation between an input electromagnetic field and the effective output generated by the N atoms. The dissipative part of the master equation and the effective single-particle Hamiltonian contain new terms due the reservoir structure of modes. In plotting the output field amplitude and phase, for a structured reservoir, as function of the input amplitude, one verifies the bistable behavior in both. We illustrate our results for two structured reservoirs: one having a Lorentzian shape for the distribution of modes, and the second is modeled as a photonic band-gap structure.
description: 9 pages, 4 figures
A magnetic continuum observed by terahertz spectroscopy in a quantum spin liquid candidate BaCo$_2$(AsO$_4$)$_2$
Creators: name: Zhang, Xinshu
name: Xu, Yuanyuan
name: Halloran, T.
name: Zhong, Ruidan
name: Cava, R. J.
name: Broholm, C.
name: Drichko, N.
name: Armitage, N. P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Quantum spin liquids (QSLs) are topologically ordered exotic states of matter that host fractionalized excitations. Kitaev proposed a particular route towards a QSL via strongly bond-dependent interactions on the hexagonal lattice. A number of candidate Kitaev QSL materials have been pursued, but all have appreciable non-Kitaev interactions, which put these systems far from the QSL regime. Using time-domain terahertz spectroscopy (TDTS) we observed a broad magnetic continuum over a wide range of temperature and field in the honeycomb cobalt-based magnet, BaCo$_2$(AsO$_4$)$_2$, which has been proposed to be more ideal versions of a Kitaev QSL. Applying a small in-plane magnetic field of $\sim$ 0.5 T suppresses the magnetic order and at at even higher fields gives rise to a spin-polarized state. With 4T magnetic field oriented principally out-of-plane, a broad magnetic continuum was observed that could be consistent with a field induced QSL. Our results indicate BaCo$_2$(AsO$_4$)$_2$ to be a promising QSL candidate.
Modelo corporativo agroindustrial (MCA)
Creators: name: Acosta Reveles, Irma Lorena
Publisher: name: figshare
Year: 2021
Subjects: subject: 140201 Agricultural Economics
subject: FOS: Economics and business
subject: 140203 Economic History
subject: Sociology
subject: FOS: Sociology
subject: 140211 Labour Economics
subject: Geography
subject: 140202 Economic Development and Growth

description: Definición para el Diccionario del Agro Iberoamericano (2021), 3ra edición ampliada. Muzlera, José y Salomón, Alejandra (Eds.). Buenos Aires: Teseopress pp. 699-703
Generating and controlling spin-polarized currents induced by a quantum spin Hall antidot
Creators: name: Dolcetto, Giacomo
name: Cavaliere, Fabio
name: Ferraro, Dario
name: Sassetti, Maura
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study an electrically controlled quantum spin Hall antidot embedded in a two-dimensional topological insulating bar. Helical edge states around the antidot and along the edges of the bar are tunnel coupled. The close connection between spin and chirality, typical of helical systems, allows to generate a spin-polarized current flowing across the bar. This current is studied as a function of the external voltages, by varying the asymmetry between the barriers. For asymmetric setups, a switching behavior of the spin current is observed as the bias is increased, both in the absence and in the presence of electron interactions. This device allows to generate and control the spin-polarized current by simple electrical means.
description: 7 pages, 6 figures
Non-destructive interrogation of nuclear waste barrels through muon tomography: A Monte Carlo study based on dual-parameter analysis via GEANT4 simulations
Creators: name: Topuz, Ahmet Ilker
name: Kiisk, Madis
name: Giammanco, Andrea
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: In this study, we employ the Monte Carlo simulations by using the GEANT4 code to demonstrate the capability of muon tomography based on the dual-parameter analysis in the examination of the nuclear waste barrels. Our current hodoscope setup consists of three top and three bottom plastic scintillators made of polyvinyl toluene with the thickness of 0.4 cm, and the composite target material is a cylindrical nuclear waste drum with the height of 96 cm and the radius of 29.6 cm where the outermost layer is stainless steel with the lateral thickness of 3.2 cm and the filling material is ordinary concrete that encapsulates the nuclear materials of dimensions 20$\times$20$\times$20 cm$^{3}$. By simulating with a narrow planar muon beam of 1$\times$1 cm$^{2}$ over the uniform energy interval between 0.1 and 8 GeV, we determine the variation of the average scattering angle together with the standard deviation by utilizing a 0.5-GeV bin length, the counts of the scattering angle by using a 1-mrad step, and the number of the absorption events for the five prevalent nuclear materials starting from cobalt and ending in plutonium. Via the duo-parametric analysis that is founded on the scattering angle as well as the absorption in the present study, we show that the presence of the nuclear materials in the waste barrels is numerically visible in comparison with the concrete-filled waste drum without any nuclear material, and the muon tomography is capable of distinguishing these nuclear materials by coupling the information about the scattering angle and the number of absorption in the cases where one of these two parameters yields strong similarity for certain nuclear materials.
description: 9 pages, 5 figures, 3 tables
Black hole spin-down by truncated disc emission
Creators: name: Abolmasov, Pavel
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The influence of disc radiation capture upon black hole rotational evolution is negligible for radiatively inefficient discs. For the standard thin disc model it is a slight but potentially important effect leading to the equilibrium spin parameter value of about 0.998. For optically thin discs, the fraction of disc radiation captured by the black hole is however about two times larger. In some disc radiation models, inner parts of the accretion flow are optically thin, advection-dominated flows, and the thin disc ends at some transition radius R_{tr}. The thermal energy of the disc stored in trapped radiation is released at this radius. Angular distribution of the radiation released at this radial photosphere facilitates its capture by the black hole. For accretion rates close to critical and disc truncation radius of (2..4) GM/c^2, radiation capture is most efficient in spinning the black hole down that may lead to a_{eq} ~ 0.996..0.997 or less depending on the mass accretion rate. For an accretion flow radiating some constant fraction εof dissipated energy, the equilibrium Kerr parameter is shown to obey the relation 1-a_{eq} \propto ε^{3/2} as long as 1-a_{eq} << 1. Deviations from Keplerian law near the last stable orbit dominate over the radiation capture effect if they exceed 1..2%.
description: 10 pages, 4 figures, accepted for publication by MNRAS
Optical Rectification and Thermal Currents in Optical Tunneling Gap Antennas
Creators: name: Mennementeuil, M. M.
name: Buret, M.
name: Francs, G. Colas des
name: Bouhelier, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Electrically-contacted optical gap antennas are nanoscale interface devices enabling the transduction between photons and electrons. This new generation of devices captures visible to near infrared electromagnetic radiation and converts the incident energy in a direct-current (DC) electrical signal. The nanoscale rectenna is usually constituted of metal elements (e.g. gold). Light absorption by the metal contacts may lead to additional thermal effects which need to be taken into account to understand the complete photo- response of the device. The purpose of this communication is to discuss the contribution of laser-induced thermo-electric effects in the photo-assisted electronic transport.
description: 9 figures
Radiation Spectrum of a Magnetized Supercritical Accretion Disc with Thermal Conduction
Creators: name: Ghasemnezhad, M.
name: Khajavi, M.
name: Abbassi, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We examine the effect of thermal conduction on the observational properties of a super critical hot magnetized flow. We obtained self-similar solution of a magnetized disc when the thermal conduction plays an important role. Follow of our first paper (Ghasemnezhad et al. 2012 (hereafter GKA12)) we have extended our solution on the observational appearance of the disc to show how physical condition such as thermal conduction, viscosity, and advection will change the observed luminosity of the disc, Continuous spectra and surface temperature of such discs was plotted. We apply the present model to black-hole X-ray binary LMC X-3 and narrow-line seyfert 1 galaxies, which are supposed to be under critical accretion rate. Our results show clearly that the surface temperature is strongly depends on the thermal conduction, the magnetic field and advection parameter. However we see that thermal conduction acts to oppose the temperature gradient as we expect and observed luminosity of the disc will reduce when thermal conduction is high. We have shown that in this model the spectra of critical accretion flows strongly depends on the inclination angle.
description: Accepted for publication, AP&SS
Study of very forward energy and its correlation with particle production at midrapidity in pp and p-Pb collisions at the LHC
Creators: name: ALICE Collaboration
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The energy deposited at very forward rapidities (very forward energy) is a powerful tool for characterising proton fragmentation in pp and p$-$Pb collisions. The correlation of very forward energy with particle production at midrapidity provides direct insights into the initial stages and the subsequent evolution of the collision. Furthermore, the correlation with the production of particles with large transverse momenta at midrapidity provides information complementary to the measurements of the underlying event, which are usually interpreted in the framework of models implementing centrality-dependent multiple parton interactions. Results about very forward energy, measured by the ALICE zero degree calorimeters (ZDCs), and its dependence on the activity measured at midrapidity in pp collisions at $\sqrt{s}=13$ TeV and in p$-$Pb collisions at $\sqrt{s_{\rm{NN}}}=8.16$ TeV are discussed. The measurements performed in pp collisions are compared with the expectations of three hadronic interaction event generators: PYTHIA 6 (Perugia 2011 tune), PYTHIA 8 (Monash tune), and EPOS LHC. These results provide new constraints on the validity of models in describing the beam remnants at very forward rapidities, where perturbative QCD cannot be used.
description: 23 pages, 11 captioned figures, 2 tables, authors from page 18, published version, figures at http://alice-publications.web.cern.ch/node/7225
A two end family of solutions for the Inhomogeneous Allen-Cahn equation in R^2
Creators: name: Agudelo, Oscar
name: Zuniga, Andres
Publisher: name: arXiv
Year: 2013
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this work we construct a family of entire bounded solution for the singulary perturbed Inhomogeneous Allen-Cahn Equation $\ep^2÷\left(a(x)\nabla u\right)-a(x)F'(u)=0$ in $\R^2$, where $\ep\to 0$. The nodal set of these solutions is close to a "nondegenerate" curve which is asymptotically two non paralell straight lines. Here $F'$ is a double-well potential and $a$ is a smooth positive function. We also provide example of curves and functions $a$ where our result applies. This work is in connection with the results found by Z.Du and B.Lai, Z.Du and C.Gui, and F. Pacard and M. Ritore, in "Transition layers for an inhomogeneus Allen-Cahn equation in Riemannian Manifolds", "Interior layers for an inhomogeneous Allen-Cahn equation", "From the constant mean curvature hypersurfaces to the gradient theory of phase transitions" respectively, where they handle the compact case.
description: arXiv admin note: text overlap with arXiv:0902.2047 by other authors
Structural disorder, magnetism, and electrical and thermoelectric properties of pyrochlore Nd2Ru2O7
Creators: name: Gaultois, Michael W.
name: Barton, Phillip T.
name: Birkel, Christina S.
name: Misch, Lauren M.
name: Rodriguez, Efrain E.
name: Stucky, Galen D.
name: Seshadri, Ram
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Polycrystalline Nd2Ru2O7 samples have been prepared and examined using a combination of structural, magnetic, and electrical and thermal transport studies. Analysis of synchrotron X-ray and neutron diffraction patterns suggests some site disorder on the A-site in the pyrochlore sublattice: Ru substitutes on the Nd-site up to 7.0(3)%, regardless of the different preparative conditions explored. Intrinsic magnetic and electrical transport properties have been measured. Ru 4d spins order antiferromagnetically at 143 K as seen both in susceptibility and specific heat, and there is a corresponding change in the electrical resistivity behaviour. A second antiferromagnetic ordering transition seen below 10 K is attributed to ordering of Nd 4f spins. Nd2Ru2O7 is an electrical insulator, and this behaviour is believed to be independent of the Ru-antisite disorder on the Nd site. The electrical properties of Nd2Ru2O7 are presented in the light of data published on all A2Ru2O7 pyrochlores, and we emphasize the special structural role that Bi3+ ions on the A-site play in driving metallic behaviour. High-temperature thermoelectric properties have also been measured. When considered in the context of known thermoelectric materials with useful figures-of-merit, it is clear that Nd2Ru2O7 has excessively high electrical resistivity which prevents it from being an effective thermoelectric. A method for screening candidate thermoelectrics is suggested.
description: 19 pages, 10 figures
Ultrasound Matrix Imaging-Part II: The distortion matrix for aberration correction over multiple isoplanatic patches
Creators: name: Lambert, William
name: Cobus, Laura A.
name: Robin, Justine
name: Fink, Mathias
name: Aubry, Alexandre
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Applied Physics (physics.app-ph)
subject: Medical Physics (physics.med-ph)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences

description: This is the second article in a series of two which report on a matrix approach for ultrasound imaging in heterogeneous media. This article describes the quantification and correction of aberration, i.e. the distortion of an image caused by spatial variations in the medium speed-of-sound. Adaptive focusing can compensate for aberration, but is only effective over a restricted area called the isoplanatic patch. Here, we use an experimentally-recorded matrix of reflected acoustic signals tosynthesize a set of virtual transducers. We then examine wave propagation between these virtual transducers and an arbitrary correction plane. Such wave-fronts consist of two components: (i) An ideal geometric wave-front linked to diffraction and the input focusing point, and; (ii) Phase distortions induced by the speed-of-sound variations. These distortions are stored in a so-called distortion matrix, the singular value decomposition of which gives access to an optimized focusing law at any point. We show that, by decoupling the aberrations undergone by the outgoing and incoming waves and applying an iterative strategy, compensation for even high-order and spatially-distributed aberrations can be achieved. After a numerical validation of the process, ultrasound matrix imaging (UMI) is applied to the in-vivo imaging of a gallbladder. A map of isoplanatic modes is retrieved and is shown to be strongly correlated with the arrangement of tissues constituting the medium. The corresponding focusing laws yield an ultrasound image with drastically improved contrast and transverse resolution. UMI thus provides a flexible and powerful route towards computational ultrasound.
description: 20 pages, 11 figures
Massive stars at low metallicity: Evolution and surface abundances of O dwarfs in the SMC
Creators: name: Bouret, Jean-Claude
name: Lanz, Thierry
name: Martins, Fabrice
name: Marcolino, Wagner L. F.
name: Hillier, D. John
name: Depagne, Eric
name: Hubeny, Ivan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the evolution, rotation, and surface abundances of O-type dwarfs in the Small Magellanic Cloud. We analyzed the UV and optical spectra of twenty-three objects and derived photospheric and wind properties. The observed binary fraction of the sample is ~ 26%, which is compatible with more systematic studies, if one considers that the actual binary fraction is potentially larger owing to low-luminosity companions and that the sample excluded obvious spectroscopic binaries. The location of the fastest rotators in the H-R diagram indicates that these could be several Myr old. The offset in the position of these fast rotators compared with the other stars confirms the predictions of evolutionary models that fast-rotating stars tend to evolve more vertically in the H-R diagram. Only one star of luminosity-class Vz, expected to best characterize extreme youth, is located on the ZAMS, the other two stars are more evolved. The distribution of nitrogen abundance of O and B stars suggests that the mechanisms responsible for the chemical enrichment of slowly rotating massive stars depends only weakly on the star's mass. We confirm that the group of slowly rotating N-rich stars is not reproduced by the evolutionary tracks. Our results call for stronger mixing in the models to explain the range of observed N abundances. All stars have an N/C ratio as a function of stellar luminosity that matches the predictions of the stellar evolution models well. More massive stars have a higher N/C ratio than the less massive stars. Faster rotators show on average a higher N/C ratio than slower rotators. The N/O versus N/C ratios agree qualitatively well with those of stellar evolution models. The only discrepant behavior is observed for the youngest two stars of the sample, which both show very strong signs of mixing, which is unexpected for their evolutionary status.
description: Accepted for publication in A&A (43 pages, 60 figures)
Metallic and insulating interfaces of amorphous SrTiO3-based oxide heterostructures
Creators: name: Chen, Yunzhong
name: Pryds, Nini
name: Kleibeuker, Josee E.
name: Koster, Gertjan
name: Sun, Jirong
name: Stamate, Eugen
name: Shen, Baogen
name: Rijnders, Guus
name: Linderoth, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices. Herein we show that metallic interfaces can be realized in SrTiO3-based heterostructures with various insulating overlayers of amorphous LaAlO3, SrTiO3 and yttria-stabilized zirconia films. On the other hand, samples of amorphous La7/8Sr1/8MnO3 films on SrTiO3 substrates remain insulating. The interfacial conductivity results from the formation of oxygen vacancies near the interface, suggesting that the redox reactions on the surface of SrTiO3 substrates play an important role.
description: 17 pages, 4 figures
Imitation and Mirror Systems in Robots through Deep Modality Blending Networks
Creators: name: Seker, M. Y.
name: Ahmetoglu, A.
name: Nagai, Y.
name: Asada, M.
name: Oztop, E.
name: Ugur, E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Learning to interact with the environment not only empowers the agent with manipulation capability but also generates information to facilitate building of action understanding and imitation capabilities. This seems to be a strategy adopted by biological systems, in particular primates, as evidenced by the existence of mirror neurons that seem to be involved in multi-modal action understanding. How to benefit from the interaction experience of the robots to enable understanding actions and goals of other agents is still a challenging question. In this study, we propose a novel method, deep modality blending networks (DMBN), that creates a common latent space from multi-modal experience of a robot by blending multi-modal signals with a stochastic weighting mechanism. We show for the first time that deep learning, when combined with a novel modality blending scheme, can facilitate action recognition and produce structures to sustain anatomical and effect-based imitation capabilities. Our proposed system, can be conditioned on any desired sensory/motor value at any time-step, and can generate a complete multi-modal trajectory consistent with the desired conditioning in parallel avoiding accumulation of prediction errors. We further showed that given desired images from different perspectives, i.e. images generated by the observation of other robots placed on different sides of the table, our system could generate image and joint angle sequences that correspond to either anatomical or effect based imitation behavior. Overall, the proposed DMBN architecture not only serves as a computational model for sustaining mirror neuron-like capabilities, but also stands as a powerful machine learning architecture for high-dimensional multi-modal temporal data with robust retrieval capabilities operating with partial information in one or multiple modalities.
Enhancing Online Learning with E-Guests: A Case Study of Postgraduate Design Students' Behavioral Intention in Chongqing, China
Creators: name: Hongwei, Ren
Publisher: name: Assumption University
Year: 2023
Subjects: E-guests
Online Learning
Postgraduates
Behavioral Intention
China

description: AU-GSB e-Journal, 16, 1, 48-56
Shear dilatancy in marginal solids
Creators: name: Tighe, Brian P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Shearing stresses can change the volume of a material via a nonlinear effect known as shear dilatancy. We calculate the elastic dilatancy coefficient of soft sphere packings and random spring networks, two canonical models of marginal solids close to their rigidity transition. We predict a dramatic enhancement of dilatancy near rigidity loss in both materials, with a surprising distinction: while packings expand under shear, networks contract. We show that contraction in networks is due to the destabilizing influence of increasing hydrostatic or uniaxial loads, which is counteracted in packings by the formation of new contacts.
description: 5 pages, 5 figures
The Darboux-Bianchi-Bäcklund transformation and soliton surfaces
Creators: name: Cieśliński, Jan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In the first part of the paper we present the dressing method which generates multi-soliton solutions to integrable systems of nonlinear partial differential equations. We compare the approach of Neugebauer with that of Zakharov, Shabat and Mikhailov. In both cases we discuss the group reductions and reductions defined by some multilinear constraints on matrices of the linear problem. The second part of the paper describes the soliton surfaces approach. The so called Sym-Tafel formula simplifies the explicit reconstruction of the surface from the knowledge of its fundamental forms, unifies various integrable nonlinearities and enables one to apply powerful methods of the theory of solitons to geometrical problems. The Darboux-Bianchi-Bäcklund transformation (i.e., the dressing method on the level of soliton surfaces) reconstructs explicitly many classical transformations of XIX century. We present examples of interesting classes of surfaces obtained from spectral problems. In particular, we consider spectral problems in Clifford algebras associated with orthogonal coordinates. Finally, compact formulas for multi-soliton surfaces are discussed and applied for the Localized Induction Equation with axial flow.
description: This is a preprint of an old paper, presented at a conference on Nonlinearity and Geometry, Warsaw (Poland) 1995, identical with the published version (1998)
The Influence of Dark Matter Halos on Dynamical Estimates of Black Hole Mass: Ten New Measurements for High-sigma Early-Type Galaxies
Creators: name: Rusli, S. P.
name: Thomas, J.
name: Saglia, R. P.
name: Fabricius, M.
name: Erwin, P.
name: Bender, R.
name: Nowak, N.
name: Lee, C. H.
name: Riffeser, A.
name: Sharp, R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Adaptive-Optics assisted SINFONI observations of the central regions of ten early-type galaxies are presented. Based primarily on the SINFONI kinematics, ten black hole masses occupying the high-mass regime of the M_BH-sigma relation are derived using three-integral Schwarzschild models. The effect of dark matter inclusion on the black hole mass is explored. The omission of a dark matter halo in the model results in a higher stellar mass-to-light ratio, especially when extensive kinematic data are used in the model. However, when the diameter of the sphere of influence -- computed using the black hole mass derived without a dark halo -- is at least 10 times the PSF FWHM during the observations, it is safe to exclude a dark matter component in the dynamical modeling, i.e. the change in black hole mass is negligible. When the spatial resolution is marginal, restricting the mass-to-light ratio to the right value returns the correct M_BH although dark halo is not present in the model. Compared to the M_BH-sigma and M_BH-L relations of McConnell et al. (2011), the ten black holes are all more massive than expected from the luminosities and seven black hole masses are higher than expected from the stellar velocity dispersions of the host bulges. Using new fitted relations which include the ten galaxies, we find that the space density of the most massive black holes (M_BH >~ 10^9 Msun) estimated from the M_BH-L relation is higher than the estimate based on the M_BH-sigma relation and the latter is higher than model predictions based on quasar counts, each by about an order of magnitude.
description: Proof corrections taken into account, AJ, in press
Synthesis in Style: Semantic Segmentation of Historical Documents using Synthetic Data
Creators: name: Bartz, Christian
name: Raetz, Hendrik
name: Otholt, Jona
name: Meinel, Christoph
name: Yang, Haojin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: One of the most pressing problems in the automated analysis of historical documents is the availability of annotated training data. The problem is that labeling samples is a time-consuming task because it requires human expertise and thus, cannot be automated well. In this work, we propose a novel method to construct synthetic labeled datasets for historical documents where no annotations are available. We train a StyleGAN model to synthesize document images that capture the core features of the original documents. While originally, the StyleGAN architecture was not intended to produce labels, it indirectly learns the underlying semantics to generate realistic images. Using our approach, we can extract the semantic information from the intermediate feature maps and use it to generate ground truth labels. To investigate if our synthetic dataset can be used to segment the text in historical documents, we use it to train multiple supervised segmentation models and evaluate their performance. We also train these models on another dataset created by a state-of-the-art synthesis approach to show that the models trained on our dataset achieve better results while requiring even less human annotation effort.
description: Code available at: https://github.com/hendraet/synthesis-in-style
The Assessment of Attitude and Behavioral Intention of E-Learning Among Art and Design Students of Chengdu Textile College in China
Creators: name: Hongxia Fu
Publisher: name: Assumption University
Year: 2023
Subjects: E-Learning
Technology Acceptance Model
The Unified Theory of Acceptance and Use of Technology
Attitude, Behavioral Intention

description: AU-GSB e-Journal, 16, 1, 57-69
Transient Chaos in BERT
Creators: name: Inoue, Katsuma
name: Ohara, Soh
name: Kuniyoshi, Yasuo
name: Nakajima, Kohei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Language is an outcome of our complex and dynamic human-interactions and the technique of natural language processing (NLP) is hence built on human linguistic activities. Bidirectional Encoder Representations from Transformers (BERT) has recently gained its popularity by establishing the state-of-the-art scores in several NLP benchmarks. A Lite BERT (ALBERT) is literally characterized as a lightweight version of BERT, in which the number of BERT parameters is reduced by repeatedly applying the same neural network called Transformer's encoder layer. By pre-training the parameters with a massive amount of natural language data, ALBERT can convert input sentences into versatile high-dimensional vectors potentially capable of solving multiple NLP tasks. In that sense, ALBERT can be regarded as a well-designed high-dimensional dynamical system whose operator is the Transformer's encoder, and essential structures of human language are thus expected to be encapsulated in its dynamics. In this study, we investigated the embedded properties of ALBERT to reveal how NLP tasks are effectively solved by exploiting its dynamics. We thereby aimed to explore the nature of human language from the dynamical expressions of the NLP model. Our short-term analysis clarified that the pre-trained model stably yields trajectories with higher dimensionality, which would enhance the expressive capacity required for NLP tasks. Also, our long-term analysis revealed that ALBERT intrinsically shows transient chaos, a typical nonlinear phenomenon showing chaotic dynamics only in its transient, and the pre-trained ALBERT model tends to produce the chaotic trajectory for a significantly longer time period compared to a randomly-initialized one. Our results imply that local chaoticity would contribute to improving NLP performance, uncovering a novel aspect in the role of chaotic dynamics in human language behaviors.
description: 11 pages, 5 figures
About Multichannel Speech Signal Extraction and Separation Techniques
Creators: name: Hidri, Adel
name: Meddeb, Souad
name: Amiri, Hamid
Publisher: name: arXiv
Year: 2012
Subjects: subject: Sound (cs.SD)
subject: FOS: Computer and information sciences

description: The extraction of a desired speech signal from a noisy environment has become a challenging issue. In the recent years, the scientific community has particularly focused on multichannel techniques which are dealt with in this review. In fact, this study tries to classify these multichannel techniques into three main ones: Beamforming, Independent Com-ponent Analysis (ICA) and Time Frequency (T-F) masking. This paper also highlights their advantages and drawbacks. However these previously mentioned techniques could not afford satisfactory results. This fact leads to the idea that a combination of those techniques, which is depicted along this study, may probably provide more efficient results. In-deed, giving the fact that those approaches are still be considered as being not totally efficient, has led us to review these mentioned above in the hope that further researches will provide this domain with suitable innovations.
description: 10 pages, 11 Figures. arXiv admin note: substantial text overlap with arXiv:1212.6080
Gravitational waves in higher-order $R^{2}$ gravity
Creators: name: Vilhena, S. G.
name: Medeiros, L. G.
name: Cuzinatto, R. R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We perform a comprehensive study of gravitational waves in the context of the higher-order quadratic scalar curvature gravity, which encompasses the ordinary Einstein-Hilbert term in the action plus an $R^{2}$ contribution and a term of the type $R\square R$. The main focus is on gravitational waves emitted by binary systems such as binary black holes and binary pulsars in the approximation of circular orbits and nonrelativistic motion. The waveform of higher-order gravitational waves from binary black holes is constructed and compared with the waveform predicted by standard general relativity; we conclude that the merger occurs earlier in our model than what would be expected from GR. The decreasing rate of the orbital period in binary pulsars is used to constrain the coupling parameters of our higher-order $R^{2}$ gravity; this is done with Hulse-Taylor binary pulsar data leading to $κ_{0}^{-1}\lesssim1.1\times10^{16}\,\text{m}^{2}$, where $κ_{0}^{-1}$ is the coupling constant for the $R^{2}$ contribution.
description: 37 pages plus appendices and references (single-column REVTeX file), 4 figures; v2: references added; v3: matches the published version; v4: typo affecting the value of the E\"ot-Wash experiment constraint corrected (results unchanged)
On the Casimir repulsion in sphere-plate geometry
Creators: name: Pirozhenko, Irina G.
name: Bordag, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The electromagnetic vacuum energy is considered in the presence of a perfectly conducting plane and a ball with dielectric permittivity $\varepsilon$ and magnetic permeability $μ$, $μ\ne1$. The attention is focused on the Casimir repulsion in this system caused by magnetic permeability of the sphere. In the case of perfectly permeable sphere, $μ=\infty$, the vacuum energy is estimated numerically. The short and long distance asymptotes corresponding to the repulsive force and respective low temperature corrections and high temperature limits are found for a wide range of $μ$. The constraints on the Casimir repulsion in this system are discussed.
description: 11 pages, 5 figures
Prompt and non-prompt J/$ψ$ production cross sections at midrapidity in proton-proton collisions at $\sqrt{s}$ = 5.02 and 13 TeV
Creators: name: ALICE Collaboration
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The production of J/$ψ$ is measured at midrapidity ($|y|<0.9$) in proton-proton collisions at $\sqrt{s}$ = 5.02 and 13 TeV, through the dielectron decay channel, using the ALICE detector at the Large Hadron Collider. The data sets used for the analyses correspond to integrated luminosities of $\mathcal{L}_{\rm int}$ = 19.4 $\pm$ 0.4 nb$^{-1}$ and $\mathcal{L}_{\rm int}$ = 32.2 $\pm$ 0.5 nb$^{-1}$ at $\sqrt{s}$ = 5.02 and 13 TeV, respectively. The fraction of non-prompt J/$ψ$ mesons, i.e. those originating from the decay of beauty hadrons, is measured down to a transverse momentum $p_{\rm T}$ = 2 GeV/$c$ (1 GeV/$c$) at $\sqrt{s}$ = 5.02 TeV (13 TeV). The $p_{\rm T}$ and rapidity ($y$) differential cross sections, as well as the corresponding values integrated over $p_{\rm T}$ and $y$, are carried out separately for prompt and non-prompt J/$ψ$ mesons. The results are compared with measurements from other experiments and theoretical calculations based on quantum chromodynamics (QCD). The shapes of the $p_{\rm T}$ and $y$ distributions of beauty quarks predicted by state-of-the-art perturbative QCD models are used to extrapolate an estimate of the $\rm b\overline{b}$ pair cross section at midrapidity and in the total phase space. The total $\rm b\overline{b}$ cross sections are found to be $σ_{\rm b \overline{\rm b}} = 541 \pm 45 (\rm stat.) \pm 69 (\rm syst.)_{-12}^{+10} (\rm extr.)~{\rm μb}$ and $σ_{\rm b \overline{\rm b}}~=~218 \pm 37 (\rm stat.) \pm 31 (\rm syst.)_{-9.1}^{+8.2} (\rm extr.)~{\rm μb}$ at $\sqrt{s}$ = 13 and 5.02 TeV, respectively. The value obtained from the combination of ALICE and LHCb measurements in pp collisions at $\sqrt{s}$ = 13 TeV is also provided.
description: 31 pages, 6 captioned figures, 2 tables, authors from page 25, published version, figures at http://alice-publications.web.cern.ch/node/7315