cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Phase diagram of the dilute magnet LiHo_xY_{1-x}F_4
Creators: name: Biltmo, A.
name: Henelius, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the effective long-range Ising dipole model with a local exchange interaction appropriate for the dilute magnetic compound LiHo_{x}Y_{1-x}F_4. Our calculations yield a value of 0.12 K for the nearest neighbor exchange interaction. Using a Monte Carlo method we calculate the phase boundary T_c(x) between the ferromagnetic and paramagnetic phases. We demonstrate that the experimentally observed linear decrease in T_c with dilution is not the simple mean-field result, but a combination of the effects of fluctuations, the exchange interaction and the hyperfine coupling. Furthermore, we find a critical dilution x_c=0.21(2), below which there is no ordering. In agreement with recent Monte Carlo simulations on a similar model, we find no evidence of the experimentally observed freezing of the glassy state in our calculation. We apply the theory of Stephen and Aharony to LiHo_{x}Y_{1-x}F_4 and find that the theory does predict a finite-temperature freezing of the spin glass. Reasons for the discrepancies are discussed.
description: 5 pages, 4 figures
Fast reactive flow simulations using analytical Jacobian and dynamic load balancing in OpenFOAM
Creators: name: Morev, Ilya
name: Tekgül, Bulut
name: Gadalla, Mahmoud
name: Shahanaghi, Ali
name: Kannan, Jeevananthan
name: Karimkashi, Shervin
name: Kaario, Ossi
name: Vuorinen, Ville
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Detailed chemistry-based computational fluid dynamics (CFD) simulations are computationally expensive due to the solution of the underlying chemical kinetics system of ordinary differential equations (ODEs). Here, we introduce a novel open-source library aiming at speeding up such reactive flow simulations using OpenFOAM, an open-source C++ software for CFD. First, our dynamic load balancing model DLBFoam (Tekgül et al., 2021) is utilized to mitigate the computational imbalance due to chemistry solution in multiprocessor reactive flow simulations. Then, the individual (cell-based) chemistry solutions are optimized by implementing an analytical Jacobian formulation using the open-source library pyJac, and by increasing the efficiency of the ODE solvers by utilizing the linear algebra package LAPACK. We demonstrate the speed-up capabilities of this new library on various combustion problems. These test problems include a 2D turbulent reacting shear layer and 3D stratified combustion to highlight the favorable scaling aspects of the library on ignition/flame front initiation setups for dual-fuel combustion. Furthermore, two fundamental 3D demonstrations are provided on non-premixed and partially premixed flames, namely the ECN Spray A and the Sandia flame D experimental configurations. The novel model offers up to two orders of magnitude speed-up for most of the investigated cases. The openly shared code along with the test case setups represent a radically new enabler for reactive flow simulations in the OpenFOAM framework.
description: 45 pages, 12 figures
Pressure-induced metal-insulator transition in MgV_2O_4
Creators: name: Baldomir, D.
name: Pardo, V.
name: Blanco-Canosa, S.
name: Rivadulla, F.
name: Rivas, J.
name: Piñeiro, A.
name: Arias, J. E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: On the basis of experimental thermoelectric power results and ab initio calculations, we propose that a metal-insulator transition takes place at high pressure (approximately 6 GPa) in MgV_2O_4.
description: 2 pages, 3 figures, accepted in Physica B (Strongly Correlated Electron Systems '07)
A new methodology for OSI conformance testing based on trace analysis
Creators: name: Wvong, Russil
Publisher: name: University of British Columbia
Year: 2010

description: This thesis discusses the problems of the conventional ISO 9646 methodology for OSI conformance testing, and proposes a new methodology based on trace analysis. In the proposed methodology, a trace analyzer is used to determine whether the observed behavior of the implementation under test is valid or invalid. This simplifies test cases dramatically, since they now need only specify the expected behavior of the IUT; unexpected behavior is checked by the trace analyzer. Test suites become correspondingly smaller. Because of this reduction in size and complexity, errors in test suites can be found and corrected far more easily. As a result, the reliability and the usefulness of the conformance testing process are greatly enhanced. In order to apply the proposed methodology, trace analyzers are needed. Existing trace analyzers are examined, and found to be unsuitable for OSI conformance testing. A family of new trace analysis algorithms is presented and proved. To verify the feasibility of the proposed methodology, and to demonstrate its benefits, it is applied to a particular protocol, the LAPB protocol specified by ISO 7776. The design and implementation of a trace analyzer for LAPB are described. The conventional ISO 8882-2 test suite for LAPB, when rewritten to specify only the expected behavior of the IUT, is found to be more than an order of magnitude smaller.
Safety Embedded Differential Dynamic Programming Using Discrete Barrier States
Creators: name: Almubarak, Hassan
name: Stachowicz, Kyle
name: Sadegh, Nader
name: Theodorou, Evangelos A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Certified safe control is a growing challenge in robotics, especially when performance and safety objectives must be concurrently achieved. In this work, we extend the barrier state (BaS) concept, recently proposed for safe stabilization of continuous time systems, to safety embedded trajectory optimization for discrete time systems using discrete barrier states (DBaS). The constructed DBaS is embedded into the discrete model of the safety-critical system integrating safety objectives into the system's dynamics and performance objectives. Thereby, the control policy is directly supplied by safety-critical information through the barrier state. This allows us to employ the DBaS with differential dynamic programming (DDP) to plan and execute safe optimal trajectories. The proposed algorithm is leveraged on various safety-critical control and planning problems including a differential wheeled robot safe navigation in randomized and complex environments and on a quadrotor to safely perform reaching and tracking tasks. The DBaS-based DDP (DBaS-DDP) is shown to consistently outperform penalty methods commonly used to approximate constrained DDP problems as well as CBF-based safety filters.
description: Added extensive quantitative comparisons and analysis in the implementation examples, and revised discussions and illustrations
Inverse cascade suppression and shear layer formation in MHD turbulence subject to a guide field and misaligned rotation
Creators: name: Benavides, Santiago J.
name: Burns, Keaton J.
name: Gallet, Basile
name: Cho, James Y-K.
name: Flierl, Glenn R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Astrophysical plasmas are often subject to both rotation and large-scale background magnetic fields. Individually, each is known to two-dimensionalize the flow in the perpendicular plane. In realistic flows, both of these effects are simultaneously present and, importantly, need not be aligned. In this work, we numerically investigate three-dimensional forced magnetohydrodynamic (MHD) turbulence subject to the competing effects of global rotation and a perpendicular background magnetic field. We focus on the case of a strong background field and find that increasing the rotation rate from zero produces significant changes in the structure of the turbulent flow. Starting with a two-dimensional inverse cascade at zero rotation, the flow first transitions to a forward cascade of kinetic energy, then to a shear-layer dominated regime, and finally to a second shear-layer regime where the kinetic energy flux is strongly suppressed and the energy transfer is mediated by the induced magnetic field. We show that the first two transitions occur at distinct values of the Rossby number, and the third occurs at a distinct value of the Lehnert number. More generally, our results demonstrate that, when considering the simultaneous limits of strong rotation and a strong guide field, the order in which those limits are taken matters in the misaligned case.
description: 17 pages, 7 figures
Entanglement in the Quantum Game of Life
Creators: name: Ney, Peter-Maximilian
name: Notarnicola, Simone
name: Montangero, Simone
name: Morigi, Giovanna
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We investigate the quantum dynamics of a spin chain that implements a quantum analog of Conway's game of life. We solve the time-dependent Schrödinger equation starting with initial separable states and analyse the evolution of quantum correlations across the lattice. We report examples of evolutions leading to all-entangled chains and/or to time oscillating entangling structures and characterize them by means of entanglement and network measures. The quantum patterns result to be quite different from the classical ones, even in the dynamics of local observables. A peculiar instance is a structure behaving as the quantum analog of a blinker, but that has no classical counterpart.
description: 12 pages, 11 figures
Large scale and large period limits of symmetric calorons
Creators: name: Harland, Derek
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct SU(2) calorons, with non-trivial holonomy, instanton charge 2 and magnetic charge 0 or -1; these calorons have two constituent monopoles, with charges (2,2) or (2,1). Our calorons are U(1)-symmetric and are constructed via the Nahm transform. They fall into distinct families which can be classified using representation theory. We consider large scale and large period limits of these calorons; in particular, the large scale limit may be a monopole, or a caloron with different topological charges.
description: 27 pages, 2 figures. Figures, proofs, and references added; typos corrected
PDF of supplementary tables and figures from Elephants develop wrinkles through both form and function
Creators: name: Schulz, Andrew K
name: Kaufmann, Lena
name: Reveyaz, Noemie
name: Ritter, Cindy
name: Hildebrandt, Thomas B
name: Brecht, Michael
Publisher: name: The Royal Society
Year: 2024
Subjects: classificationCode: 310908
subject: Animal physiology - biophysics
classificationCode: 310909
subject: Animal physiology - cell
classificationCode: 310910
subject: Animal physiology - systems

description: includes tables and figures of all of the specimens studied as well as supplemental figures on wrinkle number and histology
Periodicity of certain piecewise affine planar maps
Creators: name: Akiyama, Shigeki
name: Brunotte, Horst
name: Petho, Attila
name: Steiner, Wolfgang
Publisher: name: arXiv
Year: 2007
Subjects: subject: Dynamical Systems (math.DS)
subject: Discrete Mathematics (cs.DM)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: We determine periodic and aperiodic points of certain piecewise affine maps in the Euclidean plane. Using these maps, we prove for $λ\in\{\frac{\pm1\pm\sqrt5}2,\pm\sqrt2,\pm\sqrt3\}$ that all integer sequences $(a_k)_{k\in\mathbb Z}$ satisfying $0\le a_{k-1}+λa_k+a_{k+1}<1$ are periodic.
Higgs production at the LHC in warped extra-dimensional models
Creators: name: Djouadi, A.
name: Moreau, G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The extra-dimensional model in which the bulk geometry is a slice of anti-de Sitter space is a particularly attractive extension of the Standard Model as it allows to address the gauge hierarchy problem, as well as the mass hierarchy prevailing among fermions. However, to allow for the masses of the Kaluza-Klein excitations of the known particles to be near the Terascale without conflicting with the high-precision electroweak data, one needs to promote the gauge symmetry to a left-right structure SU(2)_L x SU(2)_R x U(1) which incorporates a new quark b', the SU(2)_R doublet partner of the heavy top quark. We show that this new quark will contribute to the main production process of Higgs bosons at the LHC: the gluon-gluon fusion mechanism which proceeds through heavy quark triangular loops. In most of the parameter space in which the measured values of the heavy t,b quark masses are reproduced, the gg -> Higgs production cross section is significantly altered, even if the b' quark is too heavy to be directly accessible, m_b' > ~1TeV. Finally, we briefly discuss the new Higgs production and decay channels involving the b' quark.
description: Latex file, 6 pages, 3 figures. Comments added, Higgs branching ratios calculated and interference modified
Quantification of discreteness effects in cosmological N-body simulations: II. Evolution up to shell crossing
Creators: name: Joyce, Michael
name: Marcos, Bruno
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We apply a recently developed perturbative formalism which describes the evolution under their self-gravity of particles displaced from a perfect lattice to quantify precisely, up to shell crossing, the effects of discreteness in dissipationless cosmological N-body simulations. We give simple expressions, explicitly dependent on the particle density, for the evolution of power in each mode as a function of red-shift. For typical starting red-shifts the effect of finite particle number is to {\it slow down} slightly the growth of power compared to that in the fluid limit (e.g. by about ten percent at half the Nyquist frequency), and to induce also dispersion in the growth as a function of direction at a comparable level. In the limit that the initial red-shift tends to infinity, at fixed particle density, the evolution in fact diverges from that in the fluid limit (described by the Zeldovich approximation). Contrary to widely held belief, this means that a simulation started at a red-shift much higher than the red-shift of shell crossing actually gives a worse, rather than a better, result. We also study how these effects are modified when there is a small-scale regularization of the gravitational force. We show that such a smoothing may reduce the anisotropy of the discreteness effects, but it then {\it increases} their average effect. This behaviour illustrates the fact that the discreteness effects described here are distinct from those usually considered in this context, due to two-body collisions. Indeed the characteristic time for divergence from the collisionless limit is proportional to $N^{2/3}$, rather than $N/ \log N$ in the latter case.
description: 18 pages, 10 figures, sequel to astro-ph/0410451 (on initial conditions), final version with minor changes, to appear in Phys. Rev. D
Supplementary materials: supplementary methods and Fig. S1-Fig. S3 from In search of the genetic variants of human sex ratio at birth: Was Fisher wrong about sex ratio evolution?
Creators: name: Song, Siliang
name: Zhang, Jianzhi
Publisher: name: The Royal Society
Year: 2024
Subjects: classificationCode: 310499
subject: Evolutionary biology not elsewhere classified

description: Supplementary materials.pdf
Can phantom transition at $z\sim 1$ restore the Cosmic concordance?
Creators: name: Zhou, Zhihuan
name: Liu, Gang
name: Mu, Yuhao
name: Xu, Lixin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The tension among inferences of Hubble constant ($H_0$) is found in a large array of datasets combinations. Modification to the late expansion history is the most direct solution to this discrepancy. In this work, we examine the viability of restoring the cosmological concordance with a novel version of transitional dark energy (TDE). The main anchors for the cosmic distance scale: cosmic microwave background (CMB) radiation, baryon acoustic oscillation (BAO), and Type Ia supernova (SNe Ia) calibrated by Cepheids form a "impossible trinity", i.e., it's plausible to reconcile with any two of the three but unlikely to accommodate them all. Particularly, the tension between BAO and the calibrated SNe Ia can not be reconciled within the scenarios of late dark energy. Nevertheless, our analysis suggests that the TDE model can reconcile with CMB and SNe Ia calibrated by its absolute magnitude ($M_{\rm{B}}$) when the equation of state (EoS) of DE transits around $z\sim1$. Meanwhile, we see a positive sign that the EoS transits with the inclusion of a local prior on $M_{\rm{B}}$, whereas the opposite is true without the $M_{\rm{B}}$ prior.
description: 12 pages, 10 figures, accepted for publication by MNRAS
CONDIZIONI DI POSSIBILITÀ PER UN PIANO DI ALFABETIZZAZIONE LESSICALE IN ITALIANO L2 PER STUDENTI INTERNAZIONALI
Creators: name: Gallina, Francesca
Publisher: name: Italiano LinguaDue
Year: 2019

description: Negli ultimi anni si è avuto un aumento del pubblico di apprendenti di italiano L2 composto da studenti stranieri inseriti in diversi contesti universitari: pur nella varietà dei percorsi che gli studenti internazionali seguono, come il programma Erasmus o il Foundation Year, condivisa è la necessità di apprendere la lingua utilizzata in ambito accademico. Il contributo affronta la questione degli usi lessicali non solo specialistici, ma soprattutto del lessico accademico, componente trasversale alle discipline e pertanto utile indipendentemente dal settore di studio, capace a nostro avviso di assumere un ruolo di pivot tra il lessico generico e quello specialistico. Verrà avanzata una proposta di piano di alfabetizzazione lessicale in italiano L2 per studenti internazionali sulla base di una sintesi delle modalità di sviluppo della competenza lessicale in contesto accademico e di una rassegna dei manuali di italiano L2 per studenti universitari, oltre che della selezione del lessico da apprendere e della varietà di attività didattiche da proporre.

Conditions for an italian L2 lexical literacy plan for international students

In recent years there has been an increase in the number of Italian L2 learners, composed of foreign students in different university contexts: despite the variety of paths that international students follow, such as the Erasmus program or the Foundation Year, the need to learn the language used in academia is a shared need. This paper addresses the issue of lexical use, not only specialized, but especially the academic lexicon, a cross-discipline component that is useful regardless of the field of study, which can be a bridge between the generic and specialized lexicons. A proposal for an Italian L2 lexical literacy plan for international students, based on a survey of lexical competence development methods in academic contexts, a review of Italian L2 manuals for university students, the selection of the lexis to be learned and a variety of teaching activities, is put forth.
description: Italiano LinguaDue, Vol 11, No 1 (2019)
Iranian staff nurses' attitudes toward nursing students
Creators: name: Karimollahi, Mansoureh
Publisher: name: figshare
Year: 2021
Subjects: Health Care

description: Introduction: Clinical education is an indispensible part of the nursing education. Clinical nurses play an
important role in this teaching learning process. The quality and quantity of student–nurse interactions in the
clinical area can either facilitate or hamper students' learning.
The rationale of this research was to probe into staff nurses' attitudes toward nursing students within the
context of clinical education in Iran. The nursing literature seems wanting in issues related to staff nurses'
attitudes toward nursing students. Thus, we draw on Peplau's interpersonal relations in nursing to address
staff–student relationship. That is, the nursing student was taken as the client.
Methods: A descriptive cross-sectional design was selected for this study. The entire staff nurses of Medical
and Surgical units (n=82) employed at Dr Fatemi and Imam Khomeini hospitals of Ardabil medical sciences
university were selected. Stagg's questionnaire and a demographic tool were used to gather data. Attitudes
were measured using a five-point Likert scale. Attitudes of staff nurses were inspected using cross tabulations
and frequencies.
Findings: The results demonstrated that attitude scores toward nursing students were low and moderate.
Some nurses (45.71%) believed that working with students is pleasant and most (98.57%) have thought that
staff should have a good relationship with nursing students. Furthermore, staff nurses pointed out that the
there is a need to overhaul the educational system of nursing students (94.3%), that nursing students do not
acquire the sufficient clinical skill (67.14%), and that the students are not prepared enough for the clinical task
(51.43%).
Conclusion: According to the results of the staffs' feelings on the relationship between nurse and student, it
seems that nurses should cultivate an atmosphere which ends to empathy, assurance and sincerity of nursing
students.
©
MISURARE L’ADEGUATEZZA FUNZIONALE IN TESTI SCRITTI DI APPRENDENTI DI ITALIANO L2
Creators: name: Orrù, Paolo
Publisher: name: Italiano LinguaDue
Year: 2019

description: Il presente lavoro prende in esame l’aspetto della valutazione dell’adeguatezza funzionale nella scrittura in lingua seconda. Si tratta di un costrutto interazionale che pone al centro l’efficacia della trasmissione di un messaggio e la felice esecuzione di un compito comunicativo. Lo studio mette alla prova una scala di valutazione per l’adeguatezza funzionale basata su quattro distinte dimensioni: contenuto, comprensibilità, risposta ai requisiti del compito, coerenza/coesione. Il testing della scala è stato realizzato grazie a 4 valutatori di madrelingua italiana non esperti, che hanno dovuto giudicare i testi prodotti da 40 informanti (studenti universitari di madrelingua ungherese iscritti nei corsi di Italianistica dell’Università di Debrecen). Il campione di apprendenti è stato costruito per rispecchiare un’ampia gamma di livelli di competenza linguistico-comunicativa (da A2 a C1). Ogni informante ha prodotto 3 testi: uno narrativo, uno argomentativo, uno regolativo. I giudizi dei valutatori sono stati incrociati per misurare attraverso una serie di test statistici: l’affidabilità globale della scala; la coerenza tra le valutazioni dei 4 partecipanti; la correlazione tra il livello di competenza degli apprendenti e le dimensioni dell’adeguatezza funzionale.

Measuring functional adequacy in written texts of italian L2 learners

The present study examines the assessment of functional adequacy in second language writing. Functional adequacy can be defined as interactional constructs that focus on the effectiveness of the transmission of a message and the successful execution of a communicative task. The study tests an evaluation scale for functional adequacy based on four distinct dimensions: content, comprehensibility, response to task requirements, coherence/cohesion. The testing of the scale was carried out thanks to 4 non-expert Italian native speakers, who had to judge the texts produced by 40 informants (Hungarian native speaking university students enrolled in Italian Studies at the University of Debrecen). The sample of learners was built to reflect a wide range of linguistic-communicative competence levels (from A2 to C1). Each informant wrote 3 texts: narrative, argumentative and instructions. A series of statistical tests were run on the evaluators' ratings in order to measure: the overall reliability of the scale; the consistency between the evaluations of the 4 participants; the correlation between the level of competence of the learners and the dimensions of functional adequacy.
description: Italiano LinguaDue, Vol 11, No 1 (2019)
Demazure embeddings are smooth
Creators: name: Losev, Ivan V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 14M17

description: We prove Brion's conjecture stating that the closure of the orbit of a self-normalizing spherical subalgebra in the corresponding Grassmanian is smooth
description: 7 pages
Energy Measurements and Preparation of Canonical Phase States of a Nano-Mechanical Resonator
Creators: name: Jacobs, Kurt
name: Jordan, Andrew N.
name: Irish, Elinor K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that a continuous quantum non-demolition measurement of the energy of a nanomechanical resonator can be achieved by monitoring the resonator with a quantum point contact via a Cooper-pair box. This technique can further be used to prepare highly non-classical states of two resonators, such as canonical phase-reference states, and so-called "noon" states.
description: 4 pages, revtex 4, 3 eps figures. v2: improvements to presentation
“IL MIO VICINO DI CASA HA UN SECONDO UFFICIO!” L’AMBIVALENZA DEL CONCETTO DI APPROPRIATEZZA COMUNICATIVA NELLA DIDATTICA DELL’ITALIANO COME SECONDA LINGUA
Creators: name: Kuitche Talè, Gilles
Publisher: name: Italiano LinguaDue
Year: 2019

description: L’autore del contributo porta in luce alcune sfaccettature del concetto di appropriatezza comunicativa nell’insegnamento/apprendimento dell’italiano L2, prendendo spunto da una esperienza di valutatore della competenza comunicativa di due tipologie di apprendenti che si avvicinano e useranno la lingua italiana in luoghi e per scopi molti diversi. E, facendo anche riferimento all’inevitabile contaminazione culturale e conseguente variazione diatopica che accompagna la diffusione di una lingua in altre regioni, si sofferma sulle caratteristiche e le esigenze della valutazione dell’appropriatezza comunicativa in situazione L2 e in situazione LS, in quanto un uso della lingua italiana efficace a livello comunicativo e pragmatico in un contesto LS, può essere considerato un errore socio-culturale in contesto L2.

“Il mio vicino di casa ha un secondo ufficio!”
The ambivalence of the concept of communicative appropriateness in the teaching of italian as a foreign language

The author highlights some facets of the concept of communicative appropriateness in teaching/learning Italian FL, taking inspiration from an experience evaluating the communicative competence of two types of learners who approach and use the Italian language in many different places and for different purposes. Inevitable cultural contamination and consequent diatopic variation accompany the spread of a language in other regions. The characteristics and needs of the assessment of communicative appropriateness in L2 and LS situations, as an effective and pragmatic use of the Italian language at the communicative level in a FL context, can be considered a socio-cultural error in an L2 context.
description: Italiano LinguaDue, V. 11, N. 1 (2019)
Flow and Arrest in Stressed Granular Materials
Creators: name: Srivastava, Ishan
name: Silbert, Leonardo E.
name: Lechman, Jeremy B.
name: Grest, Gary S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Flowing granular materials often abruptly arrest if not driven by sufficient applied stresses. Such abrupt cessation of motion can be economically expensive in industrial materials handling and processing, and is significantly consequential in intermittent geophysical phenomena such as landslides and earthquakes. Using discrete element simulations, we calculate states of steady flow and arrest for granular materials under the conditions of constant applied pressure and shear stress, which are also most relevant in practice. Here the material can dilate or compact, and flow or arrest, in response to the applied stress. Our simulations highlight that under external stress, the intrinsic response of granular materials is characterized by uniquely-defined steady states of flow or arrest, which are highly sensitive to interparticle friction. While the flowing states can be equivalently characterized by volume fraction, coordination number or internal stress ratio, to characterize the states of shear arrest, one needs to also consider the structural anisotropy in the contact network. We highlight the role of dilation in the flow-arrest transition, and discuss our findings in the context of rheological transitions in granular materials.
description: accepted version in Soft Matter. 9 pages, 5 figures
Constrained flow around a magnetic obstacle
Creators: name: Votyakov, E. V.
name: Zienicke, E.
name: Kolesnikov, Yu.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Many practical applications exploit an external local magnetic field -- magnetic obstacle -- as an essential part of their constructions. Recently, it has been demonstrated that the flow of an electrically conducting fluid influenced by an external field can show several kinds of recirculation. The present paper reports a 3D numerical study whose some results are compared with an experiment about such a flow in a rectangular duct.
description: accepted to JFM, 26 pages, 14 figures
Method for Solving Bang-Bang and Singular Optimal Control Problems using Adaptive Radau Collocation
Creators: name: Pager, Elisha R.
name: Rao, Anil V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: A method is developed for solving bang-bang and singular optimal control problems using adaptive Legendre-Gauss-Radau (LGR) collocation. The method is divided into several parts. First, a structure detection method is developed that identifies switch times in the control and analyzes the corresponding switching function for segments where the solution is either bang-bang or singular. Second, after the structure has been detected, the domain is decomposed into multiple domains such that the multiple-domain formulation includes additional decision variables that represent the switch times in the optimal control. In domains classified as bang-bang, the control is set to either its upper or lower limit. In domains identified as singular, the objective function is augmented with a regularization term to avoid the singular arc. An iterative procedure is then developed for singular domains to obtain a control that lies in close proximity to the singular control. The method is demonstrated on four examples, three of which have either a bang-bang and/or singular optimal control while the fourth has a smooth and nonsingular optimal control. The results demonstrate that the method of this paper provides accurate solutions to problems whose solutions are either bang-bang or singular when compared against previously developed mesh refinement methods that are not tailored for solving nonsmooth and/or singular optimal control problems, and produces results that are equivalent to those obtained using previously developed mesh refinement methods for optimal control problems whose solutions are smooth.
description: 37 pages, 6 figures, 5 tables To Appear in Computational Optimization and Applications
Subsonic Mechanical Alignment of Irregular Grains
Creators: name: Lazarian, Alex
name: Hoang, Thiem
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We show that grains can be efficiently aligned by interacting with a subsonic gaseous flow. The alignment arises from grains having irregularities that scatter atoms with different efficiency in the right and left directions. The grains tend to align with long axes perpendicular to magnetic field, which corresponds to Davis-Greenstein predictions. Choosing conservative estimates, scattering efficiency of impinging atoms and conservative ``degree of helicity'', the alignment of helical grains is much more efficient than the Gold-type alignment processes.
description: 12 pages, 4 figures, typos corrected
On smoothing estimates in modulation spaces and the nonlinear Schrödinger equation with slowly decaying initial data
Creators: name: Schippa, Robert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We show new local $L^p$-smoothing estimates for the Schrödinger equation with initial data in modulation spaces via decoupling inequalities. Furthermore, we probe necessary conditions by Knapp-type examples for space-time estimates of solutions with initial data in modulation and $L^p$-spaces. The examples show sharpness of the smoothing estimates up to the endpoint regularity in a certain range. Moreover, the examples rule out global Strichartz estimates for initial data in $L^p(\mathbb{R}^d)$ for $d \geq 1$ and $p > 2$, which was previously known for $d \geq 2$. The estimates are applied to show new local and global well-posedness results for the cubic nonlinear Schrödinger equation on the line. Lastly, we show $\ell^2$-decoupling inequalities for variable-coefficient versions of elliptic and non-elliptic Schrödinger phase functions.
description: revised version, 32 pages
Comment on ``Enhanced transmission of light through a gold film due to excitation of standing surface-plasmon Bloch waves"
Creators: name: Weiner, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The purpose of this comment is first to correct a misapprehension of the role played by composite wave diffraction on surface-wave generation at subwavelength structures and second to point out that periodic Bloch structures are unnecessary for the efficient production of the surface plasmon polariton (SPP) guided mode either as traveling or standing waves. Guided surface waves originate from simple slit or groove edges illuminated under normal incidence, and one-dimensional (1-D) surface cavities from these standing waves are easily realized.
description: This posting is a comment on an article, I. I. Smolyaninov and Y.-J. Hung, Phys. Rev. B 75, 033411 (2007)
Search for Frame-Dragging-Like Signals Close to Spinning Superconductors
Creators: name: Tajmar, M.
name: Plesescu, F.
name: Seifert, B.
name: Schnitzer, R.
name: Vasiljevich, I.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: High-resolution accelerometer and laser gyroscope measurements were performed in the vicinity of spinning rings at cryogenic temperatures. After passing a critical temperature, which does not coincide with the material's superconducting temperature, the angular acceleration and angular velocity applied to the rotating ring could be seen on the sensors although they are mechanically de-coupled. A parity violation was observed for the laser gyroscope measurements such that the effect was greatly pronounced in the clockwise-direction only. The experiments seem to compare well with recent independent tests obtained by the Canterbury Ring Laser Group and the Gravity-Probe B satellite. All systematic effects analyzed so far are at least 3 orders of magnitude below the observed phenomenon. The available experimental data indicates that the fields scale similar to classical frame-dragging fields. A number of theories that predicted large frame-dragging fields around spinning superconductors can be ruled out by up to 4 orders of magnitude.
description: Paper presented at the 18th International Conference on General Relativity & Gravitation, Sydney, Jul 2007 and at the Time & Matter Conference, Bled, Sept 2007, GPB Data Corrected and Model Updated
Prototype Memory for Large-scale Face Representation Learning
Creators: name: Smirnov, Evgeny
name: Garaev, Nikita
name: Galyuk, Vasiliy
name: Lukyanets, Evgeny
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Face representation learning using datasets with a massive number of identities requires appropriate training methods. Softmax-based approach, currently the state-of-the-art in face recognition, in its usual "full softmax" form is not suitable for datasets with millions of persons. Several methods, based on the "sampled softmax" approach, were proposed to remove this limitation. These methods, however, have a set of disadvantages. One of them is a problem of "prototype obsolescence": classifier weights (prototypes) of the rarely sampled classes receive too scarce gradients and become outdated and detached from the current encoder state, resulting in incorrect training signals. This problem is especially serious in ultra-large-scale datasets. In this paper, we propose a novel face representation learning model called Prototype Memory, which alleviates this problem and allows training on a dataset of any size. Prototype Memory consists of the limited-size memory module for storing recent class prototypes and employs a set of algorithms to update it in appropriate way. New class prototypes are generated on the fly using exemplar embeddings in the current mini-batch. These prototypes are enqueued to the memory and used in a role of classifier weights for softmax classification-based training. To prevent obsolescence and keep the memory in close connection with the encoder, prototypes are regularly refreshed, and oldest ones are dequeued and disposed of. Prototype Memory is computationally efficient and independent of dataset size. It can be used with various loss functions, hard example mining algorithms and encoder architectures. We prove the effectiveness of the proposed model by extensive experiments on popular face recognition benchmarks.
Application of the ferry clip approach to multi-party and interoperability testing
Creators: name: Dany, Hendra
Publisher: name: University of British Columbia
Year: 2010

description: As communications protocols are becoming more complex and sophisticated, developing a test system that has the ability to provide a controlled environment for comprehensive protocol testing is essential to achieve a "real open system". This thesis advocates the need for a multi-party test method as currently identified by ISO, and discusses two important aspects of protocol testing: Conformance and Interoperability. They are complementary to each other and are necessary to ensure the conformity and interoperability of a protocol implementation. The proposed ferry clip based test architecture is presented. Both the concepts and design principles employed to achieve a flexible and generalized test system and the specific components which comprise the Ferry Clip based Test System are described. The test system is general and flexible not only with respect to the test configurations and test methods but also with respect to the protocol to be tested, the system under test, and the underlying communication system. Applications of the ferry clip approach to multi-party conformance and interoperability testing are discussed, followed by an example of MHS conformance testing which demonstrates the applicability of the ferry clip approach to multi-party testing.
Thin Spectrum States in Superconductors
Creators: name: van Wezel, Jasper
name: Brink, Jeroen van den
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that finite size superconductors have a spectrum of states at extremely low energy, i.e. inside the superconducting gap. The presence of this {\it thin spectrum} is a generic feature and related to the fact that in a superconductor the global phase rotation symmetry is spontaneously broken. For a strong coupling superconductor we find the spectrum by exactly solving the Lieb-Mattis type Hamiltonian onto which the problem maps. One of the physical consequences of the presence of thin states is that they cause quantum decoherence in superconducting qubits of finite extent.
description: 4 pages, 2 figures
GENDER DIFFERENCES AND CLASSROOM OUTCOMES OF UNDERGRADUATES IN THE INSTITUTES OF HIGHER LEARNING
Creators: name: VERA NKIRU NWADINOBI
name: VALENTINA ANULIKA ETELE
name: FRANCIS EZIESHI MONYEI
name: WILFRED ISIOMA UKPERE
Publisher: name: Zenodo
Year: 2024
Subjects: Classroom Outcome, Gender Differences, Institute Higher Learning, Personalised Learning, Undergraduates.

description: Abstract

This conceptual study undertakes an exploratory approach to investigate the role gender differences play in the classroom outcomes of undergraduates. It is based on the premise that despite the existence of replete studies on gender difference it has mostly been discussed about variables such as performance, career advancement or family business with little to none about classroom outcomes especially as it concerns undergraduates of institutions of higher learning. This study therefore relied on literature data in its inference-making and conclusion. Findings reveal that a major influence on the classroom outcomes of undergraduates in higher learning institutes is gender differences. The reality is that education in modern times has evolved, thus demanding a holistic understanding, and a direct approach to addressing gender roles in classroom outcomes, as it remains foundational to both individual growth and academic effectiveness of undergraduates.
Effectiveness of oral motor appliances on oral motor function and speech in children: a systematic review
Creators: name: Pelkonen, Anna-Maria
name: Närhi, Linnea
name: Häkli, Sanna
name: Raatikainen, Anna-Maria
name: Pirttiniemi, Pertti
name: Silvola, Anna-Sofia
Publisher: name: Taylor & Francis
Year: 2023
Subjects: Medicine
Neuroscience
Biotechnology
Biological Sciences not elsewhere classified
Science Policy
Virology
Computational Biology

description: Different oral motor appliances have been used in connection with speech therapy to improve oral motor function and speech development, but no consensus has been reached on the effectiveness of the appliances. The objective was to systematically review the effectiveness of oral motor appliances on oral motor function and speech in children with speech sound disorders (SSDs) or oral motor dysfunctions. A systematic search was conducted up to February 2023 in the PubMed, Scopus, and Cochrane databases. Inclusion criteria were prospective randomized or case-control clinical trials investigating the effect of intraoral appliances on orofacial function and/or speech. The risk of bias was evaluated by the Cochrane Collaboration’s Robins-I tool. Nine publications of three individual studies met the inclusion and search criteria. Six of the publications were conducted in children with Down Syndrome (DS) and three publications were conducted in children with Cerebral Palsy (CP). No meta-analysis was made due to the limitations of the publications. Selected studies reported some beneficial effects of intraoral appliances on oral motor function in children with DS and CP, although the evidence is low. Due to the study design in selected studies and confounding factors, the overall risk of bias was categorized as moderate or high. Intraoral appliances may improve oral motor function in children with DS and CP. Due to lack of studies this review limited to children with DS and CP. The initial question concerning SSDs was not answered. Well-designed RCTs with larger sample sizes are needed, especially among non-syndromic children with SSDs. The level of evidence was considered very low.
Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
Creators: name: Feroz, Farhan
name: Hobson, M. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In performing a Bayesian analysis of astronomical data, two difficult problems often emerge. First, in estimating the parameters of some model for the data, the resulting posterior distribution may be multimodal or exhibit pronounced (curving) degeneracies, which can cause problems for traditional MCMC sampling methods. Second, in selecting between a set of competing models, calculation of the Bayesian evidence for each model is computationally expensive. The nested sampling method introduced by Skilling (2004), has greatly reduced the computational expense of calculating evidences and also produces posterior inferences as a by-product. This method has been applied successfully in cosmological applications by Mukherjee et al. (2006), but their implementation was efficient only for unimodal distributions without pronounced degeneracies. Shaw et al. (2007), recently introduced a clustered nested sampling method which is significantly more efficient in sampling from multimodal posteriors and also determines the expectation and variance of the final evidence from a single run of the algorithm, hence providing a further increase in efficiency. In this paper, we build on the work of Shaw et al. and present three new methods for sampling and evidence evaluation from distributions that may contain multiple modes and significant degeneracies; we also present an even more efficient technique for estimating the uncertainty on the evaluated evidence. These methods lead to a further substantial improvement in sampling efficiency and robustness, and are applied to toy problems to demonstrate the accuracy and economy of the evidence calculation and parameter estimation. Finally, we discuss the use of these methods in performing Bayesian object detection in astronomical datasets.
description: 14 pages, 11 figures, submitted to MNRAS, some major additions to the previous version in response to the referee's comments
Asymptotic symmetries at null-infinity for the Rarita-Schwinger field with magnetic term
Creators: name: Tomova, Bilyana L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we study the magnetic charges of the free massless Rarita-Schwinger field in four dimensional asymptotically flat space-time. This is the first step towards extending the study of the dual BMS charges to supergravity. The magnetic charges appear due to the addition of a boundary term in the action. This term is similar to the theta term in Yang-Mills theory. At null-infinity an infinite dimensional algebra is discovered, both for the electric and magnetic charge.