cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: The impact of gamification on the feeling of belonging among members of an online learning community
Creators: name: Grant, Matthew
Publisher: name: Memorial University of Newfoundland
Year: 2021

description: Informal online learning communities exist on some of the world’s most popular websites like Facebook and Reddit. Gamification, the use of game elements in a non-game setting (Deterdings, Dixon, Khaled, & Nacke, 2011), is also present on these two popular websites. This thesis explored how members of an online learning community felt about gamification and if it had any impact on their feelings of belonging. This thesis employed a qualitative case study methodology to explore the response of participants in two focus groups and in three interviews to gamification in informal online learning communities on Reddit. The data were coded using the method from Miles, Huberman, and Saldana (2013) and analysed using Saturate App. The coding process developed several minor themes and the major theme, “Cognizant of karma”, which illustrated that karma was only a minor motivator to participants. Participants felt receiving “downvotes” carried a sense of “judgment”, but also felt downvotes presented a learning opportunity that reinforced community boundaries. This data may suggest that participants have internalized extrinsic motivation (Gagné, Deci, Ryan, 2013) and that internalization and gamification may co-exist due to the importance both idea place on creating shared value. If this internalization could be generalized, it could show that gamification and online learning communities can coexist in a way that allows members to retain their sense of belonging.
High-energy resummation in $Λ_c$ baryon production
Creators: name: Celiberto, Francesco Giovanni
name: Fucilla, Michael
name: Ivanov, Dmitry Yu.
name: Papa, Alessandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a study on inclusive emissions of a double $Λ_c$ or of a $Λ_c$ plus a light-flavored jet system as probe channels in the semi-hard regime of QCD. Our formalism relies on the so-called hybrid high-energy/collinear factorization, where the standard collinear description is supplemented by the $t$-channel resummation à la BFKL of energy logarithms up to the next-to-leading accuracy. We make use of the JETHAD modular interface, suited to the analysis of different semi-hard reactions, employing the novel KKSS19 parameterization for the description of parton fragmentation into $Λ_c$ baryons. We provide predictions for rapidity distributions and azimuthal correlations, that can be studied at current and forthcoming LHC configurations, hunting for possible stabilizing effects of the high-energy series.
description: 28 pages, 9 figures; updated references, version published in Eur. Phys. J. C
Single-walled carbon nanotube bundle under hydrostatic pressure studied by the first-principles calculations
Creators: name: Yang, Xiaoping
name: Wu, Gang
name: Dong, Jinming
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The structural, electronic, optical and vibrational properties of the collapsed (10,10) single-walled carbon nanotube bundle under hydrostatic pressure have been studied by the first-principles calculations. Some features are observed in the present study: First, a collapsed structure is found, which is distinct from both of the herringbone and parallel structures obtained previously. Secondly, a pseudo-gap induced by the collapse appears along the symmetry axis \textit{$Γ$X}. Thirdly, the relative orientation between the collapsed tubes has an important effect on their electronic, optical and vibrational properties, which provides an efficient experimental method to distinguish unambiguously three different collapsed structures.
description: 14 pages, 6 figures
Theory of unconventional singularities of frictional shear cracks
Creators: name: Brener, Efim A.
name: Bouchbinder, Eran
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Crack-like objects that propagate along frictional interfaces, i.e.~frictional shear cracks, play a major role in a broad range of frictional phenomena. Such frictional cracks are commonly assumed to feature the universal square root near-edge singularity of ideal shear cracks, as predicted by Linear Elastic Fracture Mechanics. Here we show that this is not the generic case due to the intrinsic dependence of the frictional strength on the slip rate, even if the bodies forming the frictional interface are identical and predominantly linear elastic. Instead, frictional shear cracks feature unconventional singularities characterized by a singularity order $ξ$ that differs from the conventional $-\tfrac{1}{2}$ one. It is shown that $ξ$ depends on the friction law, on the propagation speed and on the symmetry mode of loading. We discuss the general structure of a theory of unconventional singularities, along with their implications for the energy balance and dynamics of frictional cracks. Finally, we present explicit calculations of $ξ$ and the associated near-edge fields for linear viscous-friction -- which may emerge as a perturbative approximation of nonlinear friction laws or on its own -- for both in-plane (mode-II) and anti-plane (mode-III) shear loadings.
description: 15 pages, 2 figures
RAQAMLI MEDIAKOMPETENTLIK: ILMIY ASOSLARI, TARKIBIY QISMLARI VA RIVOJLANISH OMILLARI
Creators: name: Mo'minova, Madina
Publisher: name: Zenodo
Year: 2025

description: Ushbu maqolada raqamli mediakompetentlik tushunchasi media savodxonlik, media ta’lim, raqamli media va raqamli savodxonlik bilan bog‘liq holda tahlil etiladi. Raqamli texnologiyalarning rivojlanishi va media muhitning kengayishi shaxsning media resurslardan ongli foydalanish, axborotni tahlil qilish va xavfsizlik qoidalariga rioya qilish qobiliyatini shakllantirishni talab etmoqda. Media savodxonlik va media ta’lim raqamli mediakompetentlikni rivojlantirishda asosiy vositalardan biri bo‘lib, shaxsning raqamli muhitda faoliyat yuritish qobiliyatini oshirishga xizmat qiladi. Maqolada ushbu kompetensiyalarning o‘zaro bog‘liqligi va ta’lim jarayonida ularni rivojlantirish strategiyalari yoritiladi.
Formation of the first galaxies in the aftermath of the first supernovae
Creators: name: Abe, Makito
name: Yajima, Hidenobu
name: Khochfar, Sadegh
name: Vecchia, Claudio Dalla
name: Omukai, Kazuyuki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We perform high-resolution cosmological hydrodynamic simulations to study the formation of the first galaxies that reach the masses of $10^{8-9}~h^{-1}~M_\odot$ at $z=9$. The resolution of the simulations is high enough to resolve minihaloes and allow us to successfully pursue the formation of multiple Population (Pop) III stars, their supernova (SN) explosions, resultant metal-enrichment of the inter-galactic medium (IGM) in the course of the build-up of the system. Metals are ejected into the IGM by multiple Pop III SNe, but some of the metal-enriched gas falls back onto the halo after $\gtrsim 100~\rm Myr$. The star formation history of the first galaxy depends sensitively on the initial mass function (IMF) of Pop III stars. The dominant stellar population transits from Pop III to Pop II at $z\sim 12-15$ in the case of power-law Pop III IMF, ${\rm d}n/{\rm d}M \propto M^{-2.35}$ with the mass range $10-500~M_\odot$. At $z\lesssim 12$, stars are stably formed in the first galaxies with a star formation rate of $\sim 10^{-3}$-$10^{-1}~M_\odot/{\rm yr}$. In contrast, for the case with a flat IMF, gas-deprived first galaxies form due to frequent Pop III pair-instability SNe, resulting in the suppression of subsequent Pop II star formation. In addition, we calculate UV continuum, Ly$α$- and H$α$-line fluxes from the first galaxies. We show that the James Webb Space Telescope will be able to detect both UV continuum, Ly$α$ and H$α$ line emission from first galaxies with halo mass $\gtrsim 10^{9}~M_\odot$ at $z \gtrsim 10$.
description: 14 pages, 15 figures, accepted for publication in MNRAS
Confidence Calibration for Domain Generalization under Covariate Shift
Creators: name: Gong, Yunye
name: Lin, Xiao
name: Yao, Yi
name: Dietterich, Thomas G.
name: Divakaran, Ajay
name: Gervasio, Melinda
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Existing calibration algorithms address the problem of covariate shift via unsupervised domain adaptation. However, these methods suffer from the following limitations: 1) they require unlabeled data from the target domain, which may not be available at the stage of calibration in real-world applications and 2) their performance depends heavily on the disparity between the distributions of the source and target domains. To address these two limitations, we present novel calibration solutions via domain generalization. Our core idea is to leverage multiple calibration domains to reduce the effective distribution disparity between the target and calibration domains for improved calibration transfer without needing any data from the target domain. We provide theoretical justification and empirical experimental results to demonstrate the effectiveness of our proposed algorithms. Compared against state-of-the-art calibration methods designed for domain adaptation, we observe a decrease of 8.86 percentage points in expected calibration error or, equivalently, an increase of 35 percentage points in improvement ratio for multi-class classification on the Office-Home dataset.
Tri-Partitions and Bases of an Ordered Complex
Creators: name: Edelsbrunner, Herbert
name: Ölsböck, Katharina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: Computational Geometry (cs.CG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Generalizing the decomposition of a connected planar graph into a tree and a dual tree, we prove a combinatorial analog of the classic Helmholz-Hodge decomposition of a smooth vector field. Specifically, we show that for every polyhedral complex, $K$, and every dimension, $p$, there is a partition of the set of $p$-cells into a maximal $p$-tree, a maximal $p$-cotree, and a collection of $p$-cells whose cardinality is the $p$-th Betti number of $K$. Given an ordering of the $p$-cells, this tri-partition is unique, and it can be computed by a matrix reduction algorithm that also constructs canonical bases of cycle and boundary groups.
description: 15 pages, 3 figures
Natural Language Understanding with Privacy-Preserving BERT
Creators: name: Qu, Chen
name: Kong, Weize
name: Yang, Liu
name: Zhang, Mingyang
name: Bendersky, Michael
name: Najork, Marc
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Privacy preservation remains a key challenge in data mining and Natural Language Understanding (NLU). Previous research shows that the input text or even text embeddings can leak private information. This concern motivates our research on effective privacy preservation approaches for pretrained Language Models (LMs). We investigate the privacy and utility implications of applying dx-privacy, a variant of Local Differential Privacy, to BERT fine-tuning in NLU applications. More importantly, we further propose privacy-adaptive LM pretraining methods and show that our approach can boost the utility of BERT dramatically while retaining the same level of privacy protection. We also quantify the level of privacy preservation and provide guidance on privacy configuration. Our experiments and findings lay the groundwork for future explorations of privacy-preserving NLU with pretrained LMs.
description: Accepted to CIKM 2021
Electronic and Transport Properties of Radially Deformed Double-walled Carbon Nanotube Intramolecular Junction
Creators: name: Yang, Xiaoping
name: Dong, Jinming
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The electronic and transport property of a radially deformed double-walled carbon nanotube (DWNT) intramolecular junction (IMJ) has been studied by the tight-binding (TB) model combined with the first-principle calculations. The geometrical structures of the DWNT IMJ have been first optimized in energy by the universal force field (UFF) method. It is found that when heavily squashed, the DWNT will become an insulator-coated metallic wire, and the conductance near the Fermi level has been significantly changed by the radial squash. Specially, several resonance conductance peaks appear at some energies in the conduction band of the squashed DWNT IMJ. Finally, we have also investigated the conductance variation due to change of the length of the central semiconductor in the squashed DWNT IMJ. Furthermore, a promising pure carbon nanoscale electronic device is proposed based on the DWNT IMJ.
description: 11 pages, 4 figures
SimJEB: Simulated Jet Engine Bracket Dataset
Creators: name: Whalen, Eamon
name: Beyene, Azariah
name: Mueller, Caitlin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: This paper introduces the Simulated Jet Engine Bracket Dataset (SimJEB): a new, public collection of crowdsourced mechanical brackets and accompanying structural simulations. SimJEB is applicable to a wide range of geometry processing tasks; the complexity of the shapes in SimJEB offer a challenge to automated geometry cleaning and meshing, while categorical labels and structural simulations facilitate classification and regression (i.e. engineering surrogate modeling). In contrast to existing shape collections, SimJEB's models are all designed for the same engineering function and thus have consistent structural loads and support conditions. On the other hand, SimJEB models are more complex, diverse, and realistic than the synthetically generated datasets commonly used in parametric surrogate model evaluation. The designs in SimJEB were derived from submissions to the GrabCAD Jet Engine Bracket Challenge: an open engineering design competition with over 700 hand-designed CAD entries from 320 designers representing 56 countries. Each model has been cleaned, categorized, meshed, and simulated with finite element analysis according to the original competition specifications. The result is a collection of 381 diverse, high-quality and application-focused designs for advancing geometric deep learning, engineering surrogate modeling, automated cleaning and related geometry processing tasks.
description: Final manuscript, Symposium for Geometry Processing (SGP) 2021
Lattice QCD study of a five-quark hadronic molecule
Creators: name: Cook, M. S.
name: Fiebig, H. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We compute the ground-state energies of a heavy-light K-Lambda like system as a function of the relative distance r of the hadrons. The heavy quarks, one in each hadron, are treated as static. Then, the energies give rise to an adiabatic potential Va(r) which we use to study the structure of the five-quark system. The simulation is based on an anisotropic and asymmetric lattice with Wilson fermions. Energies are extracted from spectral density functions obtained with the maximum entropy method. Our results are meant to give qualitative insight: Using the resulting adiabatic potential in a Schroedinger equation produces bound state wave functions which indicate that the ground state of the five-quark system resembles a hadronic molecule, whereas the first excited state, having a very small rms radius, is probably better described as a five-quark cluster, or a pentaquark. We hypothesize that an all light-quark pentaquark may not exist, but in the heavy-quark sector it might, albeit only as an excited state.
description: 11 pages, 15 figures, 4 tables
Fizeau Drag in Graphene Plasmonics
Creators: name: Dong, Y.
name: Xiong, L.
name: Phinney, I. Y.
name: Sun, Z.
name: Jing, R.
name: McLeod, A. S.
name: Zhang, S.
name: Liu, S.
name: Ruta, F. L.
name: Gao, H.
name: Dong, Z.
name: Pan, R.
name: Edgar, J. H.
name: Jarillo-Herrero, P.
name: Levitov, L. S.
name: Millis, A. J.
name: Fogler, M. M.
name: Bandurin, D. A.
name: Basov, D. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Dragging of light by moving dielectrics was predicted by Fresnel and verified by Fizeau's celebrated experiments with flowing water. This momentous discovery is among the experimental cornerstones of Einstein's special relativity and is well understood in the context of relativistic kinematics. In contrast, experiments on dragging photons by an electron flow in solids are riddled with inconsistencies and so far eluded agreement with the theory. Here we report on the electron flow dragging surface plasmon polaritons (SPPs): hybrid quasiparticles of infrared photons and electrons in graphene. The drag is visualized directly through infrared nano-imaging of propagating plasmonic waves in the presence of a high-density current. The polaritons in graphene shorten their wavelength when launched against the drifting carriers. Unlike the Fizeau effect for light, the SPP drag by electrical currents defies the simple kinematics interpretation and is linked to the nonlinear electrodynamics of the Dirac electrons in graphene. The observed plasmonic Fizeau drag enables breaking of time-reversal symmetry and reciprocity at infrared frequencies without resorting to magnetic fields or chiral optical pumping.
description: 11 pages, 3 figures
Effect of sonication reactor geometry on cell disruption and protein release from yeast cells
Creators: name: Bałdyga, Jerzy
name: Jasińska, Magdalena
name: Dzięgielewska, Magdalena
name: Żochowska, Monika
Publisher: name: Polish Academy of Sciences Committee of Chemical and Process Engineering
Year: 2018
Subjects: cell disruption
protein release
ultrasonication
Saccharomyces cerevisiae
yeast

description: The measured rate of release of intercellular protein from yeast cells
 by ultrasonication was applied for evaluating the effects of sonication
 reactor geometry on cell disruption rate and for validation of the
 simulation method. Disintegration of two strains of Saccharomyces
 cerevisiae has been investigated experimentally using a batch sonication
 reactor equipped with a horn type sonicator and an ultrasonic processor
 operating at the ultrasound frequency of 20 kHz. The results have shown
 that the rate of release of protein is directly proportional to the
 frequency of the emitter surface and the square of the amplitude of
 oscillations and strongly depends on the sonication reactor geometry.
 The model based on the Helmholtz equation has been used to predict
 spatial distribution of acoustic pressure in the sonication reactor.
 Effects of suspension volume, horn tip position, vessel diameter and
 amplitude of ultrasound waves on the spatial distribution of pressure
 amplitude have been simulated. A strong correlation between the rate of
 protein release and the magnitude of acoustic pressure and its spatial
 distribution has been observed. This shows that modeling of acoustic
 pressure is useful for optimization of sonication reactor geometry.
title: Acute Effects of Different Plyometric and Strength Exercises on Balance Performance in Youth Weightlifters
Creators: name: Werfelli, Hanen
name: Hammami, Raouf
name: Selmi, Mohamed Amine
name: Selmi, Walid
name: Gabrilo, Goran
name: Clark, Cain C. T.
name: Duncan, Michael
name: Sekulic, Damir
name: Granacher, Urs
name: Rebai, Haithem
Publisher: name: Universität Potsdam
Year: 2022
Subjects: subject: 610 Medizin und Gesundheit

description: Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement. Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters. Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V). Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)]. Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.
description: Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 748
Rheology of Wormlike Micellar Gels Formed By Long-Chained Zwitterionic Surfactants
Creators: name: Gupta, Ronak
name: Mitishita, Rodrigo
name: Frigaard, Ian A.
name: Elfring, Gwynn J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Long-chained surfactant solutions have found widespread use in the oil and gas industry due to a host of attractive properties. In this paper, we characterize one such commercially used viscoelastic surfactant that forms a wormlike micellar gel at room temperature and a viscoelastic solution at higher temperatures. We probe both states by conducting linear and nonlinear rheological tests and analyze their behaviour under the framework of micellar rheology. Our study outlines departure from behaviour exhibited by more conventional micellar systems and uncovers interesting dynamics like shear-induced fracture and possible shear-banding in these materials. In doing so we provide a detailed understanding of a novel class of wormlike micellar solutions
description: Corrected micellar length estimates and energetic calculations using formulae in Ref 62. Added explanatory text, Added References, Corrected typos
Expulsion (Tehcir) and Genocide (Soykirim): From Ostensible Irreconcilability to Complementarity
Creators: name: Zekiyan, Boghos
Publisher: name: Università Ca’ Foscari Venezia, Italia
Year: 2015

description:

The Armenian Genocide is still the object of a hard denial in the official attitude of Turkey's government and political circles. The Turkish term used to define what happened to the Armenians of the Ottoman Empire, in 1915, is tehcir meaning expulsion or deportation. The increasing pressure of international media, of public opinion and of the recognition process of the Armenian Genocide by a growing number of states induced, in recent years, the Turkish authotities to sustain the thesis that being a historical question, the issue of the Armenian Genocide must be discussed and resolved by historians. It happens however that, if a Turkish historian affirms the factuality of the Armenian Genocide, this can cause him/her serious problems. Hence the question seems to be entrapped in a deadlock. The paper wants to be an attempt to analyse some principles, factors and methodologies, which can help in showing a possible way out from the deadlock. It tries to elaborate some theoretical, practical and concrete proposals that will get the discussants on the way. It also examines some specific problems and hardships, which either side faces, and seeks to indicate ways that might be helpful, and tasks that might be necessary in order to overcome them. The main questions the paper faces are: the conceptual/semantic relation between genocide and tehcir in the Armenian case, the issue of trauma and the overcoming of trauma, and going beyond recognition.

description: Annali di Ca’ Foscari. Serie orientale
Intergrowth and thermoelectric properties in the Bi-Ca-Co-O system
Creators: name: Luo, X. G.
name: Jing, Y. C.
name: Chen, H.
name: Chen, X. H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Single crystals of the Bi-Ca-Co-O system have been grown using the flux method with cooling from 900$\celsius$ and 950$\celsius$, respectively. The single crystals are characterized by transmission electron microscopy and X-ray diffraction. The misfit cobaltite [Ca$_2$Bi$_{1.4}$Co$_{0.6}$O$_4$]$^{RS}$[CoO$_2$]$_{1.69}$ single crystals with quadruple ($n$=4) rocksalt (RS) layer are achieved with cooling from 900$\celsius$. Such crystal exhibits room-temperature thermoelectric power (TEP) of 180$μ$V/K, much larger than that in Sr-based misfit cobaltites with quadruple RS layer. However, intergrowth of single crystals of quadruple ($n$=4) and triple ($n$=3) RS-type layer-based misfit cobaltites is observed with cooling from 950$\celsius$. Both of TEP and resistivity were obviously enhanced by the intergrowth compared to [Ca$_2$Bi$_{1.4}$Co$_{0.6}$O$_4$]$^{RS}$[CoO$_2$]$_{1.69}$ single crystal, while the power factor at room temperature remains unchanged.
description: 8 pages, 7 figures. To be published in Journal of Crystal Growth
Ozone assessment as an EOSC-Synergy thematic service
Creators: name: Braesicke, Peter
name: Cayoglu, Ugur
name: Esteban Sanchis, Borja
name: Hardt, Marcus
name: Kerzenmacher, Tobias
name: Kozlov, Valentin
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2021

description: Ozone assessment is an important task for Climate and Environment studies. The ozone assessment service (O3as) project is going to support scientists and everyone interested in determining ozone trends for different parts of the world. It is one of the thematic services of the EOSC-Synergy project. The service applies a unified approach to analyse results from a large number of different chemistry-climate models, helps to harmonise the calculation of ozone trends efficiently and consistently, and produce publication-quality figures in a coherent and user-friendly way. Among other tasks it will aid scientists to prepare the quadrennial Global Assessment of Ozone depletion. It will also allow access to the high-level data by citizens. The service relies on several containerized components distributed across the cloud (Kubernetes) and HPC resources and leverages large scale data facility (LSDF).
Magnetic diffusion and interaction effects on Ultrahigh Energy Cosmic Rays: protons and nuclei
Creators: name: González, Juan Manuel
name: Mollerach, Silvia
name: Roulet, Esteban
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The flux of ultrahigh energy cosmic rays reaching the Earth is affected by the interactions with the cosmic radiation backgrounds as well as with the magnetic fields that are present along their trajectories. We combine the SimProp cosmic ray propagation code with a routine that allows to account for the average effects of a turbulent magnetic field on the direction of propagation of the particles. We compute in this way the modification of the spectrum which is due to the magnetic horizon effect, both for primary nuclei as well as for the secondary nuclei resulting from the photo-disintegration of the primary ones. We also provide analytic parameterizations of the attenuation effects, as a function of the magnetic field parameters and of the density of cosmic ray sources, which make it possible to obtain the expected spectra in the presence of the magnetic fields from the spectra that would be obtained in the absence of magnetic fields. The discrete nature of the distribution of sources with finite density also affects the spectrum of cosmic rays at the highest energies where the flux is suppressed due to the interactions with the radiation backgrounds, and parameterizations of these effects are obtained.
description: Matches published version
$B\to K$ Transition Form Factor up to ${\cal O}(1/m^2_b)$ within the $k_T$ Factorization Approach
Creators: name: Wu, Xing-Gang
name: Huang, Tao
name: Fang, Zhen-Yun
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the paper, we apply the $k_T$ factorization approach to deal with the $B\to K$ transition form factor $F^{B\to K}_{+,0}(q^2)$ in the large recoil regions. The B-meson wave functions $Ψ_B$ and $\barΨ_B$ that include the three-particle Fock states' contributions are adopted to give a consistent PQCD analysis of the form factor up to ${\cal O} (1/m^2_b)$. It has been found that both the wave functions $Ψ_B$ and $\barΨ_B$ can give sizable contributions to the form factor and should be kept for a better understanding of the $B$ meson decays. Then the contributions from different twist structures of the kaon wavefunction are discussed, including the $SU_f(3)$-breaking effects. A sizable contribution from the twist-3 wave function $Ψ_p$ is found, whose model dependence is discussed by taking two group of parameters that are determined by different distribution amplitude moments obtained in the literature. It is also shown that $F^{B\to K}_{+,0}(0)=0.30\pm0.04$ and $[F^{B\to K}_{+,0}(0)/F^{B\to π}_{+,0}(0)]=1.13\pm0.02$, which are more reasonable and consistent with the light-cone sum rule results in the large recoil regions.
description: 22 pages and 6 figures
Constraints on supernova progenitors from spatial correlations with H-alpha emission
Creators: name: Anderson, J. P.
name: James, P. A.
name: Salaris, M.
name: Percival, S. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have attempted to constrain the progenitors of all supernova types, through correlations of the positions of historical supernovae with recent star formation, as traced by H-alpha emission. Through pixel statistics we have found that a large fraction of the SNII population do not show any association with current star formation, which we put down to a 'runaway' fraction of these progenitors. The SNIb/c population accurately traces the H-alpha emission, with some suggestion that the SNIc progenitors show a higher degree of correlation than the SNIb, suggesting higher mass progenitors for the former. Overall the SNIa population only show a weak correlation to the positions of HII regions, but as many as a half may be associated with a young stellar population.
description: To appear in conference proceedings: "Supernova 1987A: 20 Years After -- Supernovae & Gamma-Ray Bursters", held in Aspen, February 2007
Primitive Divisors in Arithmetic Dynamics
Creators: name: Ingram, Patrick
name: Silverman, Joseph H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Number Theory (math.NT)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 11B37 (Primary), 11G99, 14G99, 37F10 (Secondary)

description: Let F(z) be a rational function in Q(z) of degree at least 2 with F(0) = 0 and such that F does not vanish to order d at 0. Let b be a rational number having infinite orbit under iteration of F, and write F^n(b) = A_n/B_n as a fraction in lowest terms. We prove that for all but finitely many n > 0, the numerator A_n has a primitive divisor, i.e., there is a prime p such that p divides A_n and p does not divide A_i for all i < n. More generally, we prove an analogous result when F is defined over a number field and 0 is a periodic point for F.
description: Version 2 is substantial revision. The proof of the main theorem has been simplified and strengthened. (16 pages)
User-centered design of identity and access management systems
Creators: name: Jaferian, Pooya
Publisher: name: Zenodo
Year: 2014
Subjects: IdM
IAM
Usable Security
HOT ID

description: IT security management (ITSM) technologies are important components of IT security in organizations. But there has been little research on how ITSM technologies should incorporate human and social issues into their design. Identity and Access Management (IAM) systems, as an important category of ITSM, share such a gap with other ITSM technologies. The overreaching goal of this research is to narrow the gap between IAM technologies and social context. In the first phase, we developed a set of usability guidelines, and heuristics for design and usability evaluation of ITSM tools. We gathered recommendations related to ITSM tools from the literature, and categorized them into a set of 19 high-level guidelines that can be used by ITSM tool designers. We then used a methodical approach to create seven heuristics for usability evaluation of ITSM tools and named them ITSM heuristics. With a between-subjects study, we compared the usage of the ITSM and Nielsen's heuristics for evaluation of a commercial IAM system. The results confirmed the effectiveness of ITSM heuristics, as participants who used the ITSM heuristics found more problems categorized as severe than those who used Nielsen's. In the second phase, we conducted a field-study of 19 security practitioners to understand how they do IAM and identify the challenges they face. We used a grounded theory approach to collect and analyze data and developed a model of IAM activities and challenges. Built on the model, we proposed a list of recommendations for improving technology or practice. In the third phase, we narrowed down our focus to a specific IAM related activity, access review. We expanded our understanding of access review by further analysis of the interviews, and by conducting a survey of 49 security practitioners. Then, we used a usability engineering process to design AuthzMap, a novel user-interface for reviewing access policies in organizations. We conducted a user study with 430 participants to compare the use of AuthzMap with two existing access review systems. The results show AuthzMap improved the efficiency in five of the seven tested tasks, and improved accuracy in one of them.
2D Cadastral Coordinate Transformation using extreme learning machine technique
Creators: name: Ziggah, Yao Yevenyo
name: Issaka, Yakubu
name: Laari, Prosper Basommi
name: Hui, Zhenyang
Publisher: name: Commitee on Geodesy PAS
Year: 2018
Subjects: radial basis function neural network
extreme learning machine
backpropagation neural network
coordinate transformation
geodetic datum

description: The Geodesy and Cartography is a semi-annually scientific journal
 publishing peer-reviewed articles with original solutions of
 theoretical, experimental or applicable problems in the field of
 geodesy, surveying engineering, cartography and GIS, cadastre and land
 management, photogrammetry, remote sensing and related disciplines.

 The Geodesy and Cartography is published under the umbrella of the
 Committee on Geodesy of the Polish Academy of Sciences (PAS).

  Printed version ISSN 2080-6736, On-line version ISSN
 2300-2581
description: Land surveyors, photogrammetrists, remote sensing engineers and
 professionals in the Earth sciences are often faced with the task of
 transferring coordinates from one geodetic datum into another to serve
 their desired purpose. The essence is to create compatibility between
 data related to different geodetic reference frames for geospatial
 applications. Strictly speaking, conventional techniques of conformal,
 affine and projective transformation models are mostly used to
 accomplish such task. With developing countries like Ghana where there
 is no immediate plans to establish geocentric datum and still rely on
 the astro-geodetic datums as it national mapping reference surface,
 there is the urgent need to explore the suitability of other
 transformation methods. In this study, an effort has been made to
 explore the proficiency of the Extreme Learning Machine (ELM) as a novel
 alternative coordinate transformation method. The proposed ELM approach
 was applied to data found in the Ghana geodetic reference network. The
 ELM transformation result has been analysed and compared with benchmark
 methods of backpropagation neural network (BPNN), radial basis function
 neural network (RBFNN), two-dimensional (2D) affine and 2D conformal.
 The overall study results indicate that the ELM can produce comparable
 transformation results to the widely used BPNN and RBFNN, but better
 than the 2D affine and 2D conformal. The results produced by ELM has
 demonstrated it as a promising tool for coordinate transformation in
 Ghana.
Dynamics of spontaneous black hole scalarization and mergers in Einstein-scalar-Gauss-Bonnet gravity
Creators: name: East, William E.
name: Ripley, Justin L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the dynamics of black holes in Einstein-scalar-Gauss-Bonnet theories that exhibit spontaneous black hole scalarization using recently introduced methods for solving the full, non-perturbative equations of motion. For one sign of the coupling parameter, non-spinning vacuum black holes are unstable to developing scalar hair, while for the other, instability only sets in for black holes with sufficiently large spin. We study scalarization in both cases, demonstrating that there is a range of parameter space where the theory maintains hyperbolic evolution and for which the instability saturates in a scalarized black hole that is stable without symmetry assumptions. However, this parameter space range is significantly smaller than the range for which stationary scalarized black hole solutions exist. We show how different choices for the subleading behavior of the Gauss-Bonnet coupling affect the dynamics of the instability and the final state, or lack thereof. Finally, we present mergers of binary black holes and demonstrate the imprint of the scalar hair in the gravitational radiation.
description: 8 pages, 6 figures; changed to match PRL version
Mixed Integer Linear Programming For Exact Finite-Horizon Planning In Decentralized Pomdps
Creators: name: Aras, Raghav
name: Dutech, Alain
name: Charpillet, François
Publisher: name: arXiv
Year: 2007
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We consider the problem of finding an n-agent joint-policy for the optimal finite-horizon control of a decentralized Pomdp (Dec-Pomdp). This is a problem of very high complexity (NEXP-hard in n >= 2). In this paper, we propose a new mathematical programming approach for the problem. Our approach is based on two ideas: First, we represent each agent's policy in the sequence-form and not in the tree-form, thereby obtaining a very compact representation of the set of joint-policies. Second, using this compact representation, we solve this problem as an instance of combinatorial optimization for which we formulate a mixed integer linear program (MILP). The optimal solution of the MILP directly yields an optimal joint-policy for the Dec-Pomdp. Computational experience shows that formulating and solving the MILP requires significantly less time to solve benchmark Dec-Pomdp problems than existing algorithms. For example, the multi-agent tiger problem for horizon 4 is solved in 72 secs with the MILP whereas existing algorithms require several hours to solve it.
Spin dynamics of the director state in frustrated hyperkagome systems
Creators: name: Jacobsen, Henrik
name: Florea, Ovidiu
name: Lhotel, Elsa
name: Lefmann, Kim
name: Petrenko, Oleg
name: Knee, Chris S.
name: Seydel, Tilo
name: Henry, Paul F.
name: Bewley, Robert
name: Voneshen, David
name: Wildes, Andrew
name: Nilsen, Gøran
name: Deen, Pascale P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present an experimental study of the magnetic structure and dynamics of two frustrated hyperkagome compounds, Gd3Ga5O12 and Gd3Al5O12. It has previously been shown that Gd3Ga5O12 exhibits long-range correlations of multipolar directors, that are formed from antiferromagnetic spins on loops of ten ions. Using neutron diffraction and Reverse Monte Carlo simulations we prove the existence of similar magnetic correlations in Gd3Al5O12, showing the ubiquity of these complex structures in frustrated hyperkagome materials. Using inelastic neutron scattering we shed further light on the director state and the associated low lying magnetic excitations. In addition we have measured quasielastic dynamics that show evidence of spin diffusion. Finally, we present AC susceptibility measurements on both Gd3Ga5O12 and Gd3Al5O12, revealing a large difference in the low frequency dynamics between the two otherwise similar compounds.
description: 13 pages, 12 figures, Accepted by Physical Review B
Modeling of emergent memory and voltage spiking in ionic transport through angström-scale slits
Creators: name: Robin, Paul
name: Kavokine, Nikita
name: Bocquet, Lydéric
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Recent advances in nanofluidics have enabled the confinement of water down to a single molecular layer. Such monolayer electrolytes show promise in achieving bio-inspired functionalities through molecular control of ion transport. However, the understanding of ion dynamics in these systems is still scarce. Here, we develop an analytical theory, backed up by molecular dynamics simulations, predicting strongly nonlinear effects in ion transport across quasi-two-dimensional slits. We show that under an electric field, ions assemble into elongated clusters, whose slow dynamics result in hysteretic conduction. This phenomenon, known as memristor effect, can be harnessed to build an elementary neuron. As a proof-of-concept, we carry out molecular simulations of two nanofluidic slits reproducing the Hodgkin-Huxley model, and observe spontaneous emission of voltage spikes characteristic of neuromorphic activity.
title: Psychosocial Moderators and Mediators of Sensorimotor Exercise in Low Back Pain: A Randomized Multicenter Controlled Trial
Creators: name: Wippert, Pia-Maria
name: Niederer, Daniel
name: Drießlein, David
name: Beck, Heidrun
name: Banzer, Winfried Eberhard
name: Schneider, Christian
name: Schiltenwolf, Marcus
name: Mayer, Frank
Publisher: name: Universitätsverlag Potsdam
Year: 2022
Subjects: subject: 610 Medizin und Gesundheit

description: The effects of exercise interventions on unspecific chronic low back pain (CLBP) have been investigated in many studies, but the results are inconclusive regarding exercise types, efficiency, and sustainability. This may be because the influence of psychosocial factors on exercise induced adaptation regarding CLBP is neglected. Therefore, this study assessed psychosocial characteristics, which moderate and mediate the effects of sensorimotor exercise on LBP. A single-blind 3-arm multicenter randomized controlled trial was conducted for 12-weeks. Three exercise groups, sensorimotor exercise (SMT), sensorimotor and behavioral training (SMT-BT), and regular routines (CG) were randomly assigned to 662 volunteers. Primary outcomes (pain intensity and disability) and psychosocial characteristics were assessed at baseline (M1) and follow-up (3/6/12/24 weeks, M2-M5). Multiple regression models were used to analyze whether psychosocial characteristics are moderators of the relationship between exercise and pain, meaning that psychosocial factors and exercise interact. Causal mediation analysis were conducted to analyze, whether psychosocial characteristics mediate the exercise effect on pain. A total of 453 participants with intermittent pain (mean age = 39.5 ± 12.2 years, f = 62%) completed the training. It was shown, that depressive symptomatology (at M4, M5), vital exhaustion (at M4), and perceived social support (at M5) are significant moderators of the relationship between exercise and the reduction of pain intensity. Further depressive mood (at M4), social-satisfaction (at M4), and anxiety (at M5 SMT) significantly moderate the exercise effect on pain disability. The amount of moderation was of clinical relevance. In contrast, there were no psychosocial variables which mediated exercise effects on pain. In conclusion it was shown, that psychosocial variables can be moderators in the relationship between sensorimotor exercise induced adaptation on CLBP which may explain conflicting results in the past regarding the merit of exercise interventions in CLBP. Results suggest further an early identification of psychosocial risk factors by diagnostic tools, which may essential support the planning of personalized exercise therapy. Level of Evidence: Level I. Clinical Trial Registration: DRKS00004977, LOE: I, MiSpEx: grant-number: 080102A/11-14. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004977.
description: Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 749