cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Αξιολόγηση και κίνητρων μαθητών: Η περίπτωση δύο τάξεων Δημοτικού Σχολείου
Creators: name: Παλιάτσιου, Ελένη Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: κίνητρα
εκπαιδευτική αξιολόγηση
μελέτη περίπτωσης
motivation
educational assessment
case study

description: Η παρούσα έρευνα αφορά στη διερεύνηση των κινήτρων μαθητών και μαθητριών σε σχέση με την αξιολόγηση. Πιο συγκεκριμένα, στόχος της είναι η μελέτη των κινήτρων μαθητών και μαθητριών και του πώς αυτά μπορούν να καλλιεργηθούν μέσα από αποτελεσματικές εκπαιδευτικές πρακτικές που χρησιμοποιεί ο/η εκπαιδευτικός της τάξης σε σχέση με την αξιολόγηση των μαθητών και μαθητριών. Καθώς τα κίνητρα συνεπάγονται ένα πολυδιάστατο χαρακτηριστικό που επηρεάζεται από πολλούς παράγοντες επιλέχθηκε να μελετηθεί και το πολιτισμικό κεφάλαιο των μαθητών και μαθητριών, με τον τρόπο που αυτό ορίζεται κατά τον Bourdieu, για να επιτευχθεί μια όσο το δυνατόν ολόπλευρη προσέγγιση τους. Πιο αναλυτικά, κατά τον Bourdieu, τα κίνητρα δεν είναι ατομικά χαρακτηριστικά, όπως ήθελε παλιότερα η επιστήμη της ψυχολογίας, αλλά αποτελεί μια συνδιαμόρφωση κοινωνικών και πολιτισμικών παραγόντων, που πρέπει να λαμβάνονται υπ’ όψη κατά τη μελέτη τους. Η μεθοδολογία της παρούσας έρευνας, λοιπόν, είναι ποιοτική καθώς πρόκειται για μια μελέτη περίπτωσης. Η έρευνα πραγματοποιήθηκε σε δύο τάξεις δύο διαφορετικών δημοτικών σχολείων της περιοχής της Θεσσαλονίκης με γνώμονα το διαφορετικό κοινωνικοοικονομικό υπόβαθρο των μαθητών και μαθητριών που αποτελούσαν το μαθητικό δυναμικό των δύο σχολείων. Η εστίαση δόθηκε στην διερεύνηση της συμβολής της σύγχρονης προσέγγισης για την εκπαιδευτική αξιολόγηση, της διαμορφωτικής αξιολόγησης, που έχει ως στόχο και θεμελιώδη προσανατολισμό την προαγωγή της μάθησης των μαθητών και μαθητριών στην οικοδόμηση κινήτρων στα παιδιά
description: This research is about the investigation of the motivation of students in relation to the assessment. More specifically, its aim is to study the motivation of pupils and how these can be cultivated through effective educational practices that the class teacher utilizes in correlation with the assessment of pupils. As incentives imply a multidimensional feature influenced by many factors, the cultural capital of pupils was also chosen to be studied, as it was defined by Bourdieu, in order to achieve a holistic approach as far as possible. More specifically, according to Bourdieu, motives are not individual characteristics, as the science of psychology previously wanted, but it is a co-transformation of social and cultural factors which need to be taken into account in their study. The methodology of the particular research, therefore, is qualitative as it is a case study. The survey was conducted in two classes of two different elementary schools in Thessaloniki region, taking into account the different socio-economic background of pupils who were the schools’ educational population. The focus was on exploring the contribution of modern approach to educational assessment, formative assessment, which sets as its aim and fundamental orientation to promote pupils’ learning in order to motivate them
Mafia: A theoretical study of players and coalitions in a partial information environment
Creators: name: Braverman, Mark
name: Etesami, Omid
name: Mossel, Elchanan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 91A18, 91A28, 60J20 (Primary)

description: In this paper, we study a game called ``Mafia,'' in which different players have different types of information, communication and functionality. The players communicate and function in a way that resembles some real-life situations. We consider two types of operations. First, there are operations that follow an open democratic discussion. Second, some subgroups of players who may have different interests make decisions based on their own group interest. A key ingredient here is that the identity of each subgroup is known only to the members of that group. In this paper, we are interested in the best strategies for the different groups in such scenarios and in evaluating their relative power. The main focus of the paper is the question: How large and strong should a subgroup be in order to dominate the game? The concrete model studied here is based on the popular game ``Mafia.'' In this game, there are three groups of players: Mafia, detectives and ordinary citizens. Initially, each player is given only his/her own identity, except the mafia, who are given the identities of all mafia members. At each ``open'' round, a vote is made to determine which player to eliminate. Additionally, there are collective decisions made by the mafia where they decide to eliminate a citizen. Finally, each detective accumulates data on the mafia/citizen status of players. The citizens win if they eliminate all mafia members. Otherwise, the mafia wins. We first find a randomized strategy that is optimal in the absence of detectives. This leads to a stochastic asymptotic analysis where it is shown that the two groups have comparable probabilities of winning exactly when the total population size is $R$ and the mafia size is of order $\sqrt{R}$. We then show that even a single detective changes the qualitative behavior of the game dramatically. Here, the mafia and citizens have comparable winning probabilities only for a mafia size linear in $R$. Finally, we provide a summary of simulations complementing the theoretical results obtained in the paper.
description: Published in at http://dx.doi.org/10.1214/07-AAP456 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Prior Knowledge and L1 and L2 grade three readers’ interacting with texts and answering questions on texts
Creators: name: Faria-Neves, Marina De
Publisher: name: University of British Columbia
Year: 2009

description: This case study explored how ten English as a First Language (Li) and ten English as a Second Language (L2) average Grade Three readers used Prior Knowledge and Non Prior Knowledge strategies to understand two Science texts and to answer three types of questions on the texts. The questions were classified according to the Pearson and Johnson taxonomy (1978). Answers to Textually Explicit questions could be found in the text; answers to Textually Implicit questions invited inferences from the text and answers to Scriptally Implicit questions required readers to use their own resources. Readers thought out loud or verbalized their thoughts after reading each sentence of the text, rated reading strategy statements, orally answered the three types of questions and then rated question-answering strategy statements. Patterns of strategies emerged from the Text and Questions protocols. Frequency counts of strategies were tallied and percentages were calculated. Analyses of the bar graphs showed that there were apparent differences between Li and L2 students in their use of Prior Knowledge and Non Prior Knowledge strategies when they read texts and answered questions on texts. It was felt that these differences indicated that Li readers seemed to be less “text-bound” or focussed on the text than L2 readers were. There were also apparent differences between the three types of questions and Li and L2 readers’ use of Prior Knowledge and Non Prior Knowledge strategies, providing evidence that the three types of questions elicited use of different types of strategies, and lending support to Wixson’s comment (1983) that the types of questions asked influenced the kinds of strategies used.
Towards a human eye behavior model by applying Data Mining Techniques on Gaze Information from IEC
Creators: name: Pallez, Denis
name: Brisson, Laurent
name: Baccino, Thierry
Publisher: name: arXiv
Year: 2008
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: In this paper, we firstly present what is Interactive Evolutionary Computation (IEC) and rapidly how we have combined this artificial intelligence technique with an eye-tracker for visual optimization. Next, in order to correctly parameterize our application, we present results from applying data mining techniques on gaze information coming from experiments conducted on about 80 human individuals.
Theoretical X-Ray Absorption Debye-Waller Factors
Creators: name: Vila, Fernando D.
name: Rehr, J. J.
name: Rossner, H. H.
name: Krappe, H. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: An approach is presented for theoretical calculations of the Debye-Waller factors in x-ray absorption spectra. These factors are represented in terms of the cumulant expansion up to third order. They account respectively for the net thermal expansion $σ^{(1)}(T)$, the mean-square relative displacements $σ^2(T)$, and the asymmetry of the pair distribution function $σ^{(3)}(T)$. Similarly, we obtain Debye-Waller factors for x-ray and neutron scattering in terms of the mean-square vibrational amplitudes $u^2(T)$. Our method is based on density functional theory calculations of the dynamical matrix, together with an efficient Lanczos algorithm for projected phonon spectra within the quasi-harmonic approximation. Due to anharmonicity in the interatomic forces, the results are highly sensitive to variations in the equilibrium lattice constants, and hence to the choice of exchange-correlation potential. In order to treat this sensitivity, we introduce two prescriptions: one based on the local density approximation, and a second based on a modified generalized gradient approximation. Illustrative results for the leading cumulants are presented for several materials and compared with experiment and with correlated Einstein and Debye models. We also obtain Born-von Karman parameters and corrections due to perpendicular vibrations.
description: 11 pages, 8 figures
Quasi-3-D Spectral Wavelet Method for a Thermal Quench Simulation
Creators: name: Bundschuh, Jonas
name: D'Angelo, Laura A. M.
name: De Gersem, Herbert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences
subject: G.1.8

description: The finite element method is widely used in simulations of various fields. However, when considering domains whose extent differs strongly in different spatial directions a finite element simulation becomes computationally very expensive due to the large number of degrees of freedom. An example of such a domain are the cables inside of the magnets of particle accelerators. For translationally invariant domains, this work proposes a quasi-3-D method. Thereby, a 2-D finite element method with a nodal basis in the cross-section is combined with a spectral method with a wavelet basis in the longitudinal direction. Furthermore, a spectral method with a wavelet basis and an adaptive and time-dependent resolution is presented. All methods are verified. As an example the hot-spot propagation due to a quench in Rutherford cables is simulated successfully.
description: 22 pages, 14 figures
Constraints on the Global Structure of Magnetic Clouds: Transverse Size and Curvature
Creators: name: Liu, Y.
name: Richardson, J. D.
name: Belcher, J. W.
name: Wang, C.
name: Hu, Q.
name: Kasper, J. C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We present direct evidence that magnetic clouds (MCs) have highly flattened and curved cross section resulting from their interaction with the ambient solar wind. Lower limits on the transverse size are obtained for three MCs observed by ACE and Ulysses from the latitudinal separation between the two spacecraft, ranging from 40$^{\circ}$ to 70$^{\circ}$. The cross-section aspect ratio of the MCs is estimated to be no smaller than $6:1$. We offer a simple model to extract the radius of curvature of the cross section, based on the elevation angle of the MC normal distributed over latitude. Application of the model to Wind observations from 1995 - 1997 (close to solar minimum) shows that the cross section is bent concavely outward by a structured solar wind with a radius of curvature of $\sim$ 0.3 AU. Near solar maximum, MCs tend to be convex outward in the solar wind with a uniform speed; the radius of curvature is proportional to the heliographic distance of MCs, as demonstrated by Ulysses observations between 1999 and 2003. These results improve our knowledge of the global morphology of MCs in the pre-Stereo era, which is crucial for space weather prediction and heliosphere studies.
description: Fully refereed, accepted for publication in JGR - Space Physics
The hollow Gaussian beam propagation on curved surface based on matrix optics method
Creators: name: Ding, Weifeng
name: Wang, Zhaoying
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: In this paper, ABCD matrix is introduced to study the paraxial transmission of light on a constant gaussian curvature surface (CGCS), which is the first time to our knowledge. It is also proved that the curved surface can be used as the implementation of fractional Fourier transform, we further generalize that we can obtain the transfer matrix of an arbitrary surface with gently varying curvature by matrix optics. As a beam propagation example, based on the Collins integral, an analytical propagation formula for the hollow Gaussian beams (HGBs) on the CGCS is derived. The propagation characteristics of HGBs on one CGCS are illustrated graphically in detail, including the change of dark spots size and splitting rays. Besides its propagation periodicity and diffraction properties, a criterion for convergence and divergence of the spot size is proposed. The area of the dark region of the HGBs can easily be controlled by proper choice of the beam parameters and the shape of CGCS. In addition, we also study the special propagation properties of the hollow beam with a fractional order. Compared with HGBs in flat space, these novel characteristics of HGBs propagation on curved surface may further expand the application range of hollow beam.
description: 11 pages, 5 figures
Functional integral treatment of some quantum nondemolition systems
Creators: name: Banerjee, Subhashish
name: Ghosh, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the scheme of a quantum nondemolition (QND) measurement, an observable is measured without perturbing its evolution. In the context of studies of decoherence in quantum computing, we examine the `open' quantum system of a two-level atom, or equivalently, a spin-1/2 system, in interaction with quantum reservoirs of either oscillators or spins, under the QND condition of the Hamiltonian of the system commuting with the system-reservoir interaction. For completeness, we also examine the well-known non-QND spin-Bose problem. For all these many-body systems, we use the methods of functional integration to work out the propagators. The propagators for the QND Hamiltonians are shown to be analogous to the squeezing and rotation operators, respectively, for the two kinds of baths considered. Squeezing and rotation being both phase space area-preserving canonical transformations, this brings out an interesting connection between the energy-preserving QND Hamiltonians and the homogeneous linear canonical transformations.
description: 16 pages, no figures
Real-Time Likelihood-Free Inference of Roman Binary Microlensing Events with Amortized Neural Posterior Estimation
Creators: name: Zhang, Keming
name: Bloom, Joshua S.
name: Gaudi, B. Scott
name: Lanusse, Francois
name: Lam, Casey
name: Lu, Jessica R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Machine Learning (cs.LG)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Fast and automated inference of binary-lens, single-source (2L1S) microlensing events with sampling-based Bayesian algorithms (e.g., Markov Chain Monte Carlo; MCMC) is challenged on two fronts: high computational cost of likelihood evaluations with microlensing simulation codes, and a pathological parameter space where the negative-log-likelihood surface can contain a multitude of local minima that are narrow and deep. Analysis of 2L1S events usually involves grid searches over some parameters to locate approximate solutions as a prerequisite to posterior sampling, an expensive process that often requires human-in-the-loop domain expertise. As the next-generation, space-based microlensing survey with the Roman Space Telescope is expected to yield thousands of binary microlensing events, a new fast and automated method is desirable. Here, we present a likelihood-free inference (LFI) approach named amortized neural posterior estimation, where a neural density estimator (NDE) learns a surrogate posterior $\hat{p}(θ|x)$ as an observation-parametrized conditional probability distribution, from pre-computed simulations over the full prior space. Trained on 291,012 simulated Roman-like 2L1S simulations, the NDE produces accurate and precise posteriors within seconds for any observation within the prior support without requiring a domain expert in the loop, thus allowing for real-time and automated inference. We show that the NDE also captures expected posterior degeneracies. The NDE posterior could then be refined into the exact posterior with a downstream MCMC sampler with minimal burn-in steps.
description: 15 pages, 8 figures, 3 tables. Accepted for publication in the Astronomical Journal. This article supersedes arXiv:2010.04156
Landau damping of electron-acoustic waves due to multi-plasmon resonances
Creators: name: Misra, Amar P.
name: Chatterjee, Debjani
name: Brodin, Gert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The linear and nonlinear theories of electron-acoustic waves (EAWs) are studied in a partially degenerate quantum plasma with two-temperature electrons and stationary ions. The initial equilibrium of electrons is assumed to be given by the Fermi-Dirac distribution at finite temperature. By employing the multi-scale asymptotic expansion technique to the one-dimensional Wigner-Moyal and Poisson equations, it is shown that the effects of multi-plasmon resonances lead to a modified complex Korteweg-de Vries (KdV) equation with a new nonlocal nonlinearity. Besides giving rise to a nonlocal nonlinear term, the wave-particle resonance also modifies the local nonlinear coupling coefficient of the KdV equation. The latter is shown to conserve the number of particles, however, the wave energy decays with time. A careful analysis shows that the two-plasmon resonance is the dominant mechanism for nonlinear Landau damping of EAWs. An approximate soliton solution of the KdV equation is also obtained, and it is shown that the nonlinear Landau damping causes the wave amplitude to decay slowly with time compared to the classical theory.
description: 13 pages, 1 figure; The revised version to appear in Physics of Plasmas (Oct 2021)
A 3D CNN Network with BERT For Automatic COVID-19 Diagnosis From CT-Scan Images
Creators: name: Tan, Weijun
name: Liu, Jingfeng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: We present an automatic COVID1-19 diagnosis framework from lung CT-scan slice images. In this framework, the slice images of a CT-scan volume are first proprocessed using segmentation techniques to filter out images of closed lung, and to remove the useless background. Then a resampling method is used to select one or multiple sets of a fixed number of slice images for training and validation. A 3D CNN network with BERT is used to classify this set of selected slice images. In this network, an embedding feature is also extracted. In cases where there are more than one set of slice images in a volume, the features of all sets are extracted and pooled into a global feature vector for the whole CT-scan volume. A simple multiple-layer perceptron (MLP) network is used to further classify the aggregated feature vector. The models are trained and evaluated on the provided training and validation datasets. On the validation dataset, the accuracy is 0.9278 and the F1 score is 0.9261.
Spectral Classification of Optical Counterparts to ROSAT All-Sky Survey X-ray Sources
Creators: name: Dragomir, Diana
name: Roy, Philippe
name: Rutledge, Robert E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Previous work statistically identified 5492 optical counterparts, with approximately 90% confidence, from among the approximately 18,000 X-ray sources appearing in the ROSAT All-Sky Survey Bright Source Catalog (RASS/BSC). Using low resolution spectra in the wavelength range 3700-7900 angstroms, we present spectroscopic classifications for 195 of these counterparts which have not previously been classified. Of these 195, we find 168 individual stars of F, G, K or M type, 6 individual stars of unknown type, 6 double stars, 6 AGN or galaxies and 7 unclassifiable objects; the spectra of the 2 remaining objects were saturated.
description: 25 pages, 7 figures
An interview with Arianna Becerril-García, Executive Director, Redalyc
Creators: name: SPARC Europe
Publisher: name: Zenodo
Year: 2020
Subjects: sustainability, open science, open access, publishing, infrastructure, funding, business models, financial models, Latin America

description: This is one of a series of interviews to share insights into the sustainability of open infrastructure services. These interviews were conducted in the Spring/Summer of 2020. This is an Invest in Open Infrastructure Project: https://investinopen.org. This work is supported by Open Society Foundations and SPARC Europe, in collaboration with Invest in Open Infrastructure. For more on this work see https://sparceurope.org/ioiinterviews
The role of $D_{(s)}^\ast$ and their contributions in $B_{(s)}\to D_{(s)} h h^\prime$ decays
Creators: name: Chai, Jian
name: Cheng, Shan
name: Wang, Wen-Fei
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We demonstrate the roles of $D_{(s)}^\ast$ and their contributions in the quasi-two-body decays $B_{(s)} \to D_{(s)} h h^\prime$ ($h, h^\prime = \{π, K\}$) in the perturbative QCD approach, stemming from the quark flavour changing $\bar{b} \to \bar{c} \, q_2 \, \bar{q}_1$ and $\bar{b} \to c \, \bar{q_1} \, \bar{q_2}$ with $q_1, q_2 = \{s/d, u\}$. The main motivation of this study is the measurements of significant derivations from the simple phase-space model in the channels $B_{(s)} \to D_{(s)} h h^\prime$ at $B$ factories and LHC, which is now clarified as the Breit-Wigner-tail effects from the corresponding intermediate resonant states $D_{(s)}^\ast$. We confirm that these effect from $D^\ast$ is small ($\sim 5\%$) in the quasi-two-body $B_{(s)} \to D ππ(K)$ decaying channels, and predict the tiny ($< 1 \%$) contributions from $D^\ast$ in the $B_{(s)} \to D_s K π(K)$ decaying channels, our result for the $B_s \to D K π(K)$ decaying channels contributed only from the Breit-Wigner-tail effect of $D_s^\ast$ is in agreement with the current LHCb measurement. We recommend the Belle-II and the LHCb collaborations to restudy the processes $B^+\to \bar D^{\ast 0}π^+(K^+) \to D^-π^+π^+(K^+)$ to reveal the structure of $D^{\ast 0}$ and the strong decay $D^{\ast 0} \to D^+ π^-$.
description: 24 pages, 3 figures, 6 tables, minor correction, typos removed
A Lorentz-Poincaré type interpretation of the Weak Equivalence Principle
Creators: name: Jan
name: Broekaert
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The validity of the Weak Equivalence Principle relative to a local inertial frame is detailed in a scalar-vector gravitation model with Lorentz-Poincaré type interpretation. Given the previously established first Post-Newtonian concordance of dynamics with General Relativity, the principle is to this order compatible with GRT. The gravitationally modified Lorentz transformations, on which the observations in physical coordinates depend, are shown to provide a physical interpretation of \emph{parallel transport}. A development of ``geodesic'' deviation in terms of the present model is given as well.
description: v1: 9 pages, 2 figures, v2: version to appear in International Journal of Theoretical Physics
Improved Perturbation Theory for Improved Lattice Actions
Creators: name: Constantinou, M.
name: Panagopoulos, H.
name: Skouroupathis, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We study a systematic improvement of perturbation theory for gauge fields on the lattice; the improvement entails resumming, to all orders in the coupling constant, a dominant subclass of tadpole diagrams. This method, originally proposed for the Wilson gluon action, is extended here to encompass all possible gluon actions made of closed Wilson loops; any fermion action can be employed as well. The effect of resummation is to replace various parameters in the action (coupling constant, Symanzik coefficients, clover coefficient) by ``dressed'' values; the latter are solutions to certain coupled integral equations, which are easy to solve numerically. Some positive features of this method are: a) It is gauge invariant, b) it can be systematically applied to improve (to all orders) results obtained at any given order in perturbation theory, c) it does indeed absorb in the dressed parameters the bulk of tadpole contributions. Two different applications are presented: The additive renormalization of fermion masses, and the multiplicative renormalization Z_V (Z_A) of the vector (axial) current. In many cases where non-perturbative estimates of renormalization functions are also available for comparison, the agreement with improved perturbative results is significantly better as compared to results from bare perturbation theory.
description: 17 pages, 3 tables, 6 figures
An interview with Heather Piwowar, Co-founder, Open Research, Canada
Creators: name: SPARC Europe
Publisher: name: Zenodo
Year: 2020
Subjects: sustainability, infrastructure, open science, open access, business models, finance models, funding

description: This is one of a series of interviews to share insights into the sustainability of open infrastructure services. These interviews were conducted in the Spring/Summer of 2020. This is an Invest in Open Infrastructure Project: https;//investinopen.org. This work is supported by Open Society Foundations and SPARC Europe, in collaboration with Invest in Open Infrastructure. For more on this work see https://sparceurope.org/ioiinterviews
Escape of ionizing radiation from star forming regions in young galaxies
Creators: name: Razoumov, Alexei O.
name: Sommer-Larsen, Jesper
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using results from high-resolution galaxy formation simulations in a standard Lambda-CDM cosmology and a fully conservative multi-resolution radiative transfer code around point sources, we compute the energy-dependent escape fraction of ionizing photons from a large number of star forming regions in two galaxies at five different redshifts from z=3.8 to 2.39. All escape fractions show a monotonic decline with time, from (at the Lyman-limit) ~6-10% at z=3.6 to ~1-2% at z=2.39, due to higher gas clumping at lower redshifts. It appears that increased feedback can lead to higher f_esc at z>3.4 via evacuation of gas from the vicinity of star forming regions and to lower f_esc at z<2.39 through accumulation of swept-up shells in denser environments. Our results agree well with the observational findings of \citet{inoue..06} on redshift evolution of f_esc in the redshift interval z=2-3.6.
description: four pages, four figures, submitted to ApJL
Low-dimensional magnetism of BaCuTe$_{2}$O$_{6}$
Creators: name: Bag, P.
name: Ahmed, N.
name: Singh, Vikram
name: Sahoo, M.
name: Tsirlin, A. A.
name: Nath, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: X-ray diffraction, thermodynamic measurements, and density-functional band-structure calculations are used to study the magnetic behavior of BaCuTe$_{2}$O$_{6}$, a member of the $A$CuTe$_2$O$_6$ structural family that hosts complex three-dimensional frustrated spin networks with possible spin-liquid physics. Temperature-dependent magnetic susceptibility and heat capacity of the Ba compound are well described by the one-dimensional spin-$\frac12$ Heisenberg chain model reminiscent of the Sr analog SrCuTe$_2$O$_6$. While the intrachain coupling $J/k_{\rm B}\simeq 37$ K is reduced compared to 49 K in the Sr compound, the Néel temperature increases from 5.5 K (Sr) to 6.1 K (Ba). Unlike the Sr compound, BaCuTe$_2$O$_6$ undergoes only one magnetic transition as a function of temperature and shows signatures of weak spin canting. We elucidate the microscopic difference between the Sr and Ba compounds and suggest that one of the interchain couplings changes sign as a result of negative pressure caused by the Sr/Ba substitution. The Néel temperature of BaCuTe$_2$O$_6$ is remarkably insensitive to the magnetic dilution with Zn$^{2+}$ up to the highest reachable level of about 20%.
description: 10 pages, 11 figures, 3 tables, Accepted in Phys. Rev. B
Bifurcation and Stability of Two-Dimensional Double-Diffusive Convection
Creators: name: Hsia, Chun-Hsiung
name: Ma, Tian
name: Wang, Shouhong
Publisher: name: arXiv
Year: 2006
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this article, we present a bifurcation and stability analysis on the double-diffusive convection. The main objective is to study 1) the mechanism of the saddle-node bifurcation and hysteresis for the problem, 2) the formation, stability and transitions of the typical convection structures, and 3) the stability of solutions. It is proved in particular that there are two different types of transitions: continuous and jump, which are determined explicitly using some physical relevant nondimensional parameters. It is also proved that the jump transition always leads to the existence of a saddle-node bifurcation and hysteresis phenomena.
Retention and motivation of French as a second language among students of varying abilities
Creators: name: MacDicken-Jones, Kathleen Susan
Publisher: name: University of British Columbia
Year: 2009

description: Teachers routinely conduct a period of review after a semester or summer holiday break due to expected loss of material learned. In the area of second language (L2) acquisition, this matter is of particular concern to instructors and students because, in general, during the period of disuse students have had little, if any, contact with the language. One factor which has proven to influence the maintenance of an L2 is that of motivation. Gardner and his colleagues’ (1959, 1971, 1973, 1985, 1987, 1988) studies of French as a Second Language (FSL) have highlighted strong correlations between attitude and achievement and achievement and language retention. Research on individual differences among learners (Brounstein, Holahan, William, & Sawyer, 1988; Gardner, 1990) has also contributed to identifying what leads to a successful learner. This study examined the loss of linguistic and reading comprehension skills among learners of all ability levels in FSL, with a focus on high ability learners, following summer vacation. In addition, between-group comparisons of motivational factors, as based upon subjects’ pre-test scores were conducted. Tests performed consisted of an analysis of exam questions and components to confirm an equal level of difficulty of both test versions used, as well as tests of reliability. Pre- and post-test measures were compared to identify any loss incurred, followed by Pearson correlations and t-tests. Ability groupings were then categorized as high, medium, and low according to their pre-test scores. Within these groupings, questionnaire statistics were calculated and contrasted to highlight any motivational differences between them. Findings from this research suggested that language skills among FSL learners of varying abilities deteriorate significantly after a period of disuse. In addition, these findings confirmed that highly proficient FSL learners are more immune to attrition due to their having a more stable language base. With reference to the motivational questionnaires, analyses concluded few significant differences among the three ability levels.
Micropolar continua as projective space of Skyrmions
Creators: name: Lee, Yongjo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Micropolar continua are shown to be the generalisation of the nematic liquid crystals through perspectives of order parameters, topological and geometrical considerations. Micropolar continua and nematic liquid crystals are recognised as the antipodals of $S^3$ and $S^2$ in projective geometry. We show that position-dependent rotational axial fields in kinematic micropolar continua can be considered as solutions of anisotropic Higgs fields, characterised by integers N. We emphasise that the identical integers N are topological invariants through homotopy classifications based on defects of order parameters and a finite energy requirement. Magnetic monopoles and Skyrmions are investigated based on the theories of defects of continua in Riemann-Cartan manifolds.
description: 25 pages: v2 extended references and minor corrections
สถาบันอุดมศึกษากับความอาทรต่อสังคม
Creators: name: อุทัย  ดุลยเกษม
Publisher: name: วิทยาลัยเทคโนโลยีภาคใต้
Year: 2558

description: 1, 8, วารสารเทคโนโลยีภาคใต้
ผลของการจัดการเรียนรู้ตามรูปแบบการต่อบทเรียนและรูปแบบการจัดกลุ่มแบบช่วยรายบุคคล ที่มีต่อผลสัมฤทธิ์ทางการเรียนวิชาคณิตศาสตร์ของนักเรียนชั้นประถมศึกษาปีที่ 3
Creators: name: วิไลรัตน์  ชูช่วย
Publisher: name: วิทยาลัยเทคโนโลยีภาคใต้
Year: 2558
Subjects: การเรียนรู้แบบร่วมมือรูปแบบการต่อบทเรียน รูปแบบการจัดกลุ่มแบบช่วยรายบุคคล ผลสัมฤทธิ์ทางการเรียน

description: 1, 8, วารสารเทคโนโลยีภาคใต้
Infinitesimal deformations of restricted simple Lie algebras II
Creators: name: Viviani, Filippo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 17B50, 17B20, 17B56

description: We compute the infinitesimal deformations of two families of restricted simple Lie algebras: the contact and the Hamiltonian algebras.
description: 26 pages, final version, to appear on J. Pure and Applied Algebra
General properties of the evolution of unstable states at long times
Creators: name: Urbanowski, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: An effect generated by the nonexponential behavior of the survival amplitude of an unstable state at the long time region is considered. It is known that this amplitude tends to zero as $t$ goes to the infinity more slowly than any exponential function of $t$. Using methods of asymptotic analysis we find the asymptotic form of this amplitude in the long time region in a general model independent case. We find that the long time behavior of this amplitude affects the form of the energy of unstable states: This energy should be much smaller for suitably long times $t$ than the energy of this state for $t$ of the order of the lifetime of the considered unstable state.
description: 12 pages, new comments and references added, accepted for publication in The European Physical Journal D
Checkerboard and stripe inhomogeneities in cuprates
Creators: name: Seibold, G.
name: Lorenzana, J.
name: Grilli, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We systematically investigate charge-ordering phases by means of a restricted and unrestricted Gutzwiller approximation to the single-band Hubbard model with nearest ($t$) and next-nearest neighbor hopping ($t'$). When $|t'/t|$ is small, as appropriate for ${\rm La_{2-x}Sr_xCuO_4}$, stripes are found, whereas in compounds with larger $|t'/t|$ (such as ${\rm Ca_{2-x}Na_x CuO_2Cl_2}$ and ${\rm Bi_2Sr_2CaCu_2O_{8+δ}}$) checkerboard structures are favored. In contrast to the linear doping dependence found for stripes the charge periodicity of checkerboard textures is locked to 4 unit cells over a wide doping range. In addition we find that checkerboard structures are favored at surfaces.
description: 5 pages, 3 figures
Summer school Open science and scholarship 2019 - Utrecht University
Creators: name: Bosman, Jeroen
name: Kramer, Bianca
Publisher: name: Zenodo
Year: 2020
Subjects: open science
open scholarship
open research
summer school
utrecht university
open science skills
open science training

description: From August 26th-30th 2019, Utrecht University hosted the 3rd edition of the summer school course
 ‘Open Science and Scholarship – changing your research workflow’  The one-week, full-time course is aimed at researchers of all disciplines and career levels, interested in learning how to make open science integral part of their own research practice. The 2019 course was aimed specifically at researchers at Utrecht University, but the materials can be re-used and modified by anyone. We use participants’ own workflow and outputs as starting point (from getting funding to doing your research in the open, making your research more visible and being rewarded for openness). The course alternates between theory, discussing that theory and immediately putting that theory into practice. The course touches on open science goals and funding, open access, open data, open peer review, assessment, reproducibility, doing outreach and more. At the end of the course, participants have a toolbox of practical approaches making research more open and will have started applying some of them. They will also have a better understanding of the benefits of doing so, and how to deal with existing barriers towards open science and scholarship. The course also enables participants to continue the conversation about open science at their department, as all course materials are made available for reuse.
description: Slides provided as pdf and pptx, syllabus (with programme and materials) provided as pdf; syllabus is also available online at https://tinyurl.com/sumsopenscience2019
On the universality of AdS$_2$ diffusion bounds and the breakdown of linearized hydrodynamics
Creators: name: Wu, Ning
name: Baggioli, Matteo
name: Li, Wei-Jia
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The chase of universal bounds on diffusivities in strongly coupled systems and holographic models has a long track record. The identification of a universal velocity scale, independent of the presence of well-defined quasiparticle excitations, is one of the major challenges of this program. A recent analysis, valid for emergent IR fixed points exhibiting local quantum criticality, and dual to IR AdS$_2$ geometries, suggests to identify such a velocity using the time and length scales at which hydrodynamics breaks down -- the equilibration velocity. The latter relates to the radius of convergence of the hydrodynamic expansion and it is extracted from a collision between a hydrodynamic diffusive mode and a non-hydrodynamic mode associated to the IR AdS$_2$ region. In this short note, we confirm this picture for holographic systems displaying the spontaneous breaking of translational invariance. Moreover, we find that, at zero temperature, the lower bound set by quantum chaos and the upper one defined by causality and hydrodynamics exactly coincide, determining uniquely the diffusion constant. Finally, we comment on the meaning and universality of this newly proposed prescription.
description: v2: numerical inaccuracies fixed, figures and presentation improved, matching the published version in JHEP
Θεωρητικά Ζητήματα του Σχολείου Εργασίας
Creators: name: Ελληνικάκης, Ματθαίος Εμμανουήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Σχολεία Εργασίας
Κοινότητα
Χειρονακτική Εργασία
Schools of Labor
Community
Manual Labor

description: Η παρούσα μεταπτυχιακή εργασία εξετάζει τις θεωρίες και τις πρακτικές εμπειρίες των σχολείων εργασίας, όπως αυτές εμφανίζονται στην παιδαγωγική σκέψη του 19ου και στις αρχές του 20ου αιώνα. Ειδικότερα, διερευνούνται τα παιδαγωγικά εγχειρήματα των Ντιούι, Κερσενστάινερ και Μακάρενκο, καθώς μέσα από αυτά διαφαίνονται σημαντικοί τρόποι ένταξης της χειρωνακτικής άσκησης στην παιδαγωγική διαδικασία. Το πειραματικό σχολείο του Σικάγο, που εγκαινιάζει ο Ντιούι το 1896, τα επιμορφωτικά σχολεία του Μονάχου, που αναλαμβάνει ο Κερσενστάινερ το 1914 και ο παιδικός σταθμός Μαξίμ Γκόρκι που ανοίγει τις πύλες του για τα ορφανά παιδιά του δρόμου το 1920, υπό την διεύθυνση του Μακάρενκο, έρχονται στο προσκήνιο της εργασίας, αναδεικνύοντας ως βασικούς πυλώνες της διαπαιδαγώγησης την κοινότητα, την σχολική αυτοδιοίκηση και την χειρωνακτική άσκηση. Σε τελική ανάλυση, η εργασία επιχειρεί μια συγκριτική ανάλυση και μια κριτική αποτίμηση των θεωρητικών αυτών ζητημάτων των σχολείων εργασίας, συμπεριλαμβάνοντας την μαρξιστική θέση για την ένταξη της χειρωνακτικής εργασίας στην εκπαίδευση. Απώτερος στόχος είναι η ανάδειξη νέων προοπτικών για μια σύγχρονη απελευθερωτική εκπαίδευση
description: This master thesis examines the theories and practical experiences of Schools of labor as they appear in the 19th and early 20th century pedagogical thinking. In particular, the pedagogical ventures of Dewey, Kerstensteiner and Makarenko are being explored, as there are important ways of integrating manual exercise into the pedagogical process. Chicago's experimental school founded by Dewey in 1896, the Munich School of Education, which was taken over by Kersensteiner in 1914, and the kindergarden of Maxim Gorky, that opened its gates for street orphan children in 1920, under the direction of Makarenko, come to the forefront of work, highlighting community, school self-government and manual exercise as the main elements of education. Ultimately, the work attempts a comparative analysis and critical assessment of these theoretical issues of schools of Labor, including the Marxist approach about inclusion of manual labor in education. The ultimate goal is the emergence of new perspectives for an education for liberation in our days
Limit theorems for random point measures generated by cooperative sequential adsorption
Creators: name: Shcherbakov, V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 82C21 (Primary) 60F05, 60F15, 60G55 (Secondary)

description: We consider a finite sequence of random points in a finite domain of a finite-dimensional Euclidean space. The points are sequentially allocated in the domain according to a model of cooperative sequential adsorption. The main peculiarity of the model is that the probability distribution of a point depends on previously allocated points. We assume that the dependence vanishes as the concentration of points tends to infinity. Under this assumption the law of large numbers, the central limit theorem and Poisson approximation are proved for the generated sequence of random point measures.
description: 17 pages
Asymmetric steerability of quantum equilibrium and nonequilibrium steady states through entanglement detection
Creators: name: Zhang, Kun
name: Wang, Jin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Einstein-Podolsky-Rosen steering describes a quantum correlation in addition to entanglement and Bell nonlocality. However, conceptually different from entanglement and Bell nonlocality, quantum steering has an asymmetric definition. Motivated by the asymmetric definition of quantum steering, we study the steerability of two-interacting qubits, which have asymmetric energy levels, coupled with asymmetric environments. The asymmetric (nonequilibrium) environments are two environments with different temperatures or chemical potentials. The Bloch-Redfield equation is applied to study the dynamics of two qubits and its long-time behavior. In our study, the steady-state steerability is determined by an experimentally friendly steering criteria, which demonstrates steering through the entanglement detection. Our results show that the steady states of two asymmetric qubits have the advantage for one direction of steering, compared to the symmetric setup. We also provide analytical results on the minimal coupling strength between the two qubits in order to be steerable. The asymmetric steerability is collectively determined by the nature of the two qubits and the influence from equilibrium or nonequilibrium environments. Nonequilibrium environments with the cost of nonzero entropy production can enhance the steerability in one direction. We also show the strict hierarchy of entanglement, steering and Bell nonlocality of the nonequilibrium steady states, which shows a richer structure of steering than entanglement and Bell nonlocality.
description: Published version, 17 pages, 11 figures
Non-source items are a serious problem everywhere
Creators: name: Mayr, Philipp
Publisher: name: Zenodo
Year: 2020
Subjects: reference extraction, non-source items, bibliographic databases

description: Making bibliographic data available for researchers, scholars and others is important in all disciplines to ensure easy and fast access to the literature and other scientific resources such as research datasets. Our previous project EXCITE has addressed this problem and narrowed the gap between the availability of citation data in the social sciences. EXCITE has researched, developed, and deployed powerful tools (https://github.com/exciteproject/) that localize, extract and segment reference strings in PDF documents and then match them against bibliographic databases. One of the main conclusions derived from EXCITE is that the metadata of approx. 60% of the cited papers and other scientific resources are outside of available bibliographic databases. The extracted reference strings (items) that could not be matched are called “non-source items” (NSI). NSI include incomplete or erroneous references as well as references that indeed do not exist in the available bibliographic databases, especially references to datasets, websites and other material. This talk will highlight the significance of NSI for citation matching and suggest possible algorithms to reduce the amount of NSI in digital libraries. Presentation given at the Workshop On Open Citations And Open Scholarly Metadata 2020 (Virtual Event)
description: Presentation given at the Workshop On Open Citations And Open Scholarly Metadata 2020 (Virtual Event)