bluuebunny/crossref_metadata_2025_split huggingface dataset:
How English-Medium Instruction affects language and learning outcomes of children in the Maldives
Authors: Bosch Jasmijn E. , Tsimpli Ianthi M. , Guasti Maria Teresa 
Published: December 2022

Abstract
Whilst the vast majority of the Maldivian population speak Dhivehi at home, English typically serves as the only
medium of instruction (MoI) starting from primary school. Teachers have expressed their concerns regarding educational quality, as
many children are taught in a language they do not master sufficiently. The present study aimed to investigate the level of second
language (L2) proficiency in relation to reading abilities and mathematical skills in 25 ten- to twelve-year-old children living
in the Maldives. The results showed relatively low performance on all tasks, despite normal nonverbal intelligence. Moreover, we
found a significant relation between English vocabulary knowledge and reading accuracy. Our findings contribute to a growing body
of research suggesting that using an L2 as the only MoI may be detrimental to literacy development and learning outcomes.
Considering the objectives of educational quality, language maintenance of Dhivehi and the pragmatic value assigned to English, we
argue in favour of a bilingual model of education, in which the importance of native language development is emphasized.
Noether charge formalism for Weyl transverse gravity
Authors: Alonso-Serrano Ana , Garay Luis J , Liška Marek 
Published: December 2022

Abstract
Weyl transverse gravity (WTG) is a gravitational theory that is invariant under transverse diffeomorphisms and Weyl transformations. It is characterised by having the same classical solutions as general relativity while solving some of its issues with the cosmological constant. In this work, we first find the Noether currents and charges corresponding to local symmetries of WTG as well as a prescription for the symplectic form. We then employ these results to derive the first law of black hole mechanics in WTG (both in vacuum and in the presence of a perfect fluid), identifying the total energy, the total angular momentum, and the Wald entropy of black holes. We further obtain the first law and Smarr formula for Schwarzschild-anti-de Sitter and pure de Sitter spacetimes, discussing the contributions of the varying cosmological constant, which naturally appear in WTG. Lastly, we derive the first law of causal diamonds in vacuum.
Building post-Newtonian neutron stars
Authors: Andersson Nils , Gittins Fabian , Yin Shanshan , Panosso Macedo Rodrigo 
Published: December 2022

Abstract
Owed to their compactness, neutron stars involve strong gravity and extreme density physics. Nevertheless, at present, there are a variety of problems where progress (at least conceptually) can be made in the context of weak gravity. Motivated by this we examine how accurately one can model neutron stars using the post-Newtonian (pN) approximation to general relativity. In general, we find there is a significant degree of freedom in how the pN equations of stellar structure can be formulated. We discuss this flexibility in the formulation and provide examples to demonstrate the impact on stellar models. We also consider the (closely related) problem of building neutron stars using isotropic coordinates. In this context, we provide a new strategy for solving the equations (based on a scaling argument) which significantly simplifies the problem.
Current loop and point dipole configurations for magnetic multipoles
Authors: Majic Matt 
Published: December 2022

Abstract
Multipoles are a widely used tool in magnetostatics, but very little is known about the possible current distributions that may generate them. Here we propose constructions for the currents corresponding to the multipole fields. We begin with a small current loop which creates a dipolar field, and then investigate how to construct current configurations for multipoles of all degrees and orders, by using differentiation and considering ideas of symmetry and nesting loops. We also investigate using point dipoles instead of loops. Many equivalent configurations are found, most of which are not presented elsewhere in the literature.
Weighted envelope spectrum based on reselection mechanism and its application in bearing fault diagnosis
Authors: Zhang Yongxiang , Huang Baoyu 
Published: December 2022

Abstract
As a powerful algorithm, fast spectral correlation (Fast-SC) is widely used in bearing fault diagnosis. However, the interference of strong background noise and the existence of multiple fault-related frequency bands make it difficult to diagnose bearing faults using enhanced envelope spectrum and improved envelope spectrum on the basis of Fast-SC. To alleviate the problem, fast kurtogram is imitated to divide the spectral frequency bands; then, the threshold-based diagnostic feature (TDF) of each integration band is calculated to guide the weighting function of the corresponding level; finally, weighted envelope spectrum with the largest TDF is determined as the output; this process is called the reselection mechanism. Simulation and experimental results indicate that the design of weighting function highlights the contribution of the fault-related frequency bands, and the reselection mechanism further improves its performance.
Identification of wind turbine gearbox weak compound fault based on optimal empirical wavelet transform
Authors: Hu Mantang , Wang Guofeng , Ma Kaile 
Published: December 2022

Abstract
A double modulation phenomenon is found in wind turbine gearbox compound fault signals, consisting of a resonance modulation frequency band and an asymmetric modulation frequency band. The modal aliasing and the double modulation phenomena make it difficult to use empirical wavelet transform to obtain the spectral components in the meshing modulation regions. Our main contribution is to establish an optimal empirical wavelet transform (OEWT) framework for weak feature extraction of compound faults, which incorporates the optimal velocity synchronous linear chirplet transform (OVSLCT) and the simulated annealing (SA) algorithm to obtain the optimal parameters of the filter bank. The frequency boundary of the fault component is obtained through OVSLCT rather than the extreme value of the spectrum. A filter transition band width optimization scheme is proposed in which the optimal transition band width of the filter bank in EWT is optimized by the SA algorithm. Compared with the original EWT and variational mode decomposition, OEWT can better obtain the compound fault characteristic frequency and solve the mode aliasing problem.
DeSeg: auto detector-based segmentation for brain metastases
Authors: Yu Hui , Zhang Zhongzhou , Xia Wenjun , Liu Yan , Liu Lunxin , Luo Wuman , Zhou Jiliu , Zhang Yi 
Published: December 2022

Abstract
Delineation of brain metastases (BMs) is a paramount step in stereotactic radiosurgery treatment. Clinical practice has specific expectation on BM auto-delineation that the method is supposed to avoid missing of small lesions and yield accurate contours for large lesions. In this study, we propose a novel coarse-to-fine framework, named detector-based segmentation (DeSeg), to incorporate object-level detection into pixel-wise segmentation so as to meet the clinical demand. DeSeg consists of three components: a center-point-guided single-shot detector to localize the potential lesion regions, a multi-head U-Net segmentation model to refine contours, and a data cascade unit to connect both tasks smoothly. Performance on tiny lesions is measured by the object-based sensitivity and positive predictive value (PPV), while that on large lesions is quantified by dice similarity coefficient (DSC), average symmetric surface distance (ASSD) and 95% Hausdorff distance (HD95). Besides, computational complexity is also considered to study the potential of method in real-time processing. This study retrospectively collected 240 BM patients with Gadolinium injected contrast-enhanced T1-weighted magnetic resonance imaging (T1c-MRI), which were randomly split into training, validating and testing datasets (192, 24 and 24 scans, respectively). The lesions in the testing dataset were further divided into two groups based on the volume size (small S: ≤1.5 cc, N = 88; large L: > 1.5 cc, N = 15). On average, DeSeg yielded a sensitivity of 0.91 and a PPV of 0.77 on S group, and a DSC of 0.86, an ASSD 0f 0.76 mm and a HD95 of 2.31 mm on L group. The results indicated that DeSeg achieved leading sensitivity and PPV for tiny lesions as well as segmentation metrics for large ones. After our clinical validation, DeSeg showed competitive segmentation performance while kept faster processing speed comparing with existing 3D models.
The effect of intermediate layer densification on the critical current of a Bi-2223 superconducting joint
Authors: Takeda Y , Nishijima G , Inoue K , Takano Y , Kitaguchi H 
Published: December 2022

Abstract
The effect of intermediate layer densification on the critical current (I
c) of Bi-2223 superconducting joints was quantitatively studied. First, we evaluated the phase purity, density, and intergrain critical current density (J
c) of Bi-2223 thick film samples simulating the intermediate layer. The samples were uniaxially pressed to increase the film density. After two heat treatments of the pressed film, an increase in J
c was achieved. Second, we fabricated superconducting joints by synthesizing an intermediate layer between two Bi-2223 tapes. Applying a uniform uniaxial pressure on the joint resulted in the formation of a homogeneous structure. This process enables the reproducible fabrication of superconducting joints with high n values. The I
c of the superconducting joint was increased by intermediate pressing (IP) and two heat treatments. However, pressing at high pressures can mechanically damage filaments in the Bi-2223 tapes, leading to a decrease in I
c. Sample characterization showed that the optimum IP pressure range to produce high I
c was 1.5–2 × 108 Pa. We confirmed that pressing densified the intermediate layer of the superconducting joints. Our experimental results and analyses reveal that densification of the intermediate layer increases the I
c of Bi-2223 superconducting joints.
Efficient positron trapping and extraction with a center-hole SiC remoderator
Authors: Michishio Koji , Higaki Hiroyuki , Ishida Akira , Oshima Nagayasu 
Published: December 2022

Abstract
Trapping technologies of positrons, the antimatter counterpart of electrons, are indispensable for various atomic, molecular, and optical experiments and for material analyses that use positron swarms. Efficient trapping of high-intensity positron beams generated by electron linear accelerators (LINACs) will improve the quality and throughput rate of experiments but have yet to be practically realized. In the present work, we demonstrate the efficient trapping and extraction of a LINAC-based positron beam by using a silicon carbide (SiC) remoderator with a center hole. The positron beam was remoderated by 4H-SiC wafers in the back-reflection geometry followed by accumulation in an electromagnetic trap with CF4 cooling gas. A rotating electric field was driven to spatially compress the accumulated positrons, enabling the lossless extraction of the positrons through the SiC hole. A trapping efficiency in the higher 20% range was achieved. The proposed trapping scheme employing a center-hole SiC remoderator is thus a practical technique to accumulate and cool positron beams generated by LINACs.
Enhancing quantum coherence of a fluxonium qubit by employing flux modulation with tunable-complex-amplitude
Authors: Cheng Jia-Ming , Zhang Yong-Chang , Zhou Xiang-Fa , Zhou Zheng-Wei 
Published: December 2022

Abstract
We propose to protect fluxonium qubits that are away from half flux quantum against environmental noises, especially

1

/

f

flux noise, by adopting a modulated flux with tunable-complex-amplitude. Using open-system Floquet theory, we derive a Lindblad equation and extract decoherent rates for pure-dephasing, excitation and relaxation. After examining intrinsic attributes of the flux driven fluxonium qubit, we put forward an analytic manner to locate dynamical sweet spots for fast and weak driving. Continuous families of dynamical sweet spots are found in the parameter plane of relative amplitude factor and relative phase. Around a family of dynamical sweet spots or between two families of dynamical sweet spots, there exist continuous regions with long coherent times that exceed

100

μ

s

. Taking advantage of the two noise-insensitive channels: relative amplitude factor and relative phase, a flux driven fluxonium qubit can become immune to flux noises from both the dc and ac flux amplitudes. And the optimal driving amplitudes are no longer isolated at a certain driving frequency, but become continuous. This is in sharp contrast to the usual schemes based on flux modulation with real-amplitude. As a result, there are plenty of manipulating flexibility in our flux driving scheme with tunable-complex-amplitude, which may be useful in logical operations among flux driven fluxonium qubits or other flux qubits.
Controlled quantum teleportation between discrete and continuous physical systems
Authors: El Kirdi M , Slaoui A , Ikken N , Daoud M , Ahl Laamara R 
Published: December 2022

Abstract
Quantum teleportation of an unknown state basing on the interaction between discrete-valued states (DV) and continuous-valued states (CV) presented a particular challenge in quantum technologies. Here we consider the problem of controlled quantum teleportation of an amplitude-matched CV qubit, encoded by a coherent state of a varied phase as a superposition of the vacuum- and single-photon optical states among two distant partners Alice and Bob, with the consent of controller, Charlie. To achieve this task, we use an hybrid tripartite entangled state (interaction between the discrete and continuous variables states) as the quantum resource where the coherent part belongs to Alice, while the single-photon belongs to Bob and Charlie and the CV qubit is at the disposal of Alice. The discrete-continuous interaction is realized on highly transmissive beam-splitter. We have shown that the perfectly of teleportation fidelity depends on the phase difference between the phase of the state to teleport and the phase of the sender’s mode, we found that for a difference which approaches 0 or π, near perfect controlled quantum teleportation can be obtained in terms of the fidelity and independently of the amplitude α and the squeezing parameter ζ. Experimentally, this proposed scheme has been implemented using linear optical components such as beam splitter, phase shifters and photon counters.
Neural network reconstruction of H'(z) and its application in teleparallel gravity
Authors: Mukherjee Purba , Said Jackson Levi , Mifsud Jurgen 
Published: December 2022

Abstract
In this work, we explore the possibility of using artificial neural networks to impose constraints on teleparallel gravity and its f(T) extensions. We use the available Hubble parameter observations from cosmic chronometers and baryon acoustic oscillations from different galaxy surveys. We discuss the procedure for training a network model to reconstruct the Hubble diagram. Further, we describe the procedure to obtain H'(z), the first order derivative of H(z), using artificial neural networks which is a novel approach to this method of reconstruction. These analyses are complemented with further studies on the impact of two priors which we put on H
0 to assess their impact on the analysis, which are the local measurements by the SH0ES team (H
0
R20 = 73.2 ± 1.3 km Mpc-1 s-1) and the updated TRGB calibration from the Carnegie Supernova Project (H
0
TRGB = 69.8 ± 1.9 km Mpc-1 s-1), respectively. Additionally, we investigate the validity of the concordance model, through some cosmological null tests with these reconstructed data sets. Finally, we reconstruct the allowed f(T) functions for different combinations of the observational Hubble data sets. Results show that the ΛCDM model lies comfortably included at the 1σ confidence level for all the examined cases.
A Candid Assessment of Standard Cosmology
Authors: Melia Fulvio 
Published: December 2022

Abstract
Modern cosmology is broadly based on the Cosmological principle, which assumes homogeneity and isotropy as its foundational pillars. Thus, there is not much debate about the metric (i.e., Friedmann-Lemaître-Robertson-Walker; FLRW) one should use to describe the cosmic spacetime. But Einstein’s equations do not unilaterally constrain the constituents in the cosmic fluid, which directly determine the expansion factor appearing in the metric coefficients. As its name suggests, ΛCDM posits that the energy density is dominated by a blend of dark energy (typically a cosmological constant, Λ), cold dark matter (and a “contamination” of baryonic matter) and radiation. Many would assert that we have now reached the age of “precision” cosmology, in which measurements are made merely to refine the excessively large number of free parameters characterizing its empirical underpinnings. But this mantra glosses over a growing body of embarrassingly significant failings, not just “tension” as is sometimes described, as if to somehow imply that a resolution will eventually be found. In this paper, we take a candid look at some of the most glaring conflicts between the standard model, the observations, and several foundational principles in quantum mechanics, general relativity and particle physics. One cannot avoid the conclusion that the standard model needs a complete overhaul in order to survive.
Global SOLPS-ITER and ERO2.0 coupling in a linear device for the study of plasma–wall interaction in helium plasma
Authors: Alberti G. , Tonello E. , Carminati P. , Uccello A. , Bonnin X. , Romazanov J. , Brezinsek S. , Passoni M. 
Published: December 2022

Abstract
Plasma–wall interaction (PWI) is a great challenge in the development of a nuclear fusion power plant. To investigate phenomena like erosion of plasma-facing components, impurity transport and redeposition, one needs reliable numerical tools for the description of both the plasma and the material evolution. The development of such tools is essential to guide the design and interpretation of experiments in present and future fusion devices. This contribution presents the first global simulation of PWI processes in a linear plasma device mimicking the boundary plasma conditions in toroidal ones, including both the description of plasma and impurity transport and of plasma-facing material evolution. This integrated description is obtained by coupling two of the state-of-the-art numerical codes employed to model the plasma boundary and the PWI, namely SOLPS-ITER and ERO2.0. Investigation of helium plasma is also of primary importance due to the role helium will have during ITER pre-fusion power operation, when it is planned to be used as one of the main plasma species, as well as fusion ash in full power operation. The plasma background is simulated by SOLPS-ITER and the set of atomic reactions for helium plasmas is updated, including charge-exchange and radiative heat losses. ERO2.0 is used to assess the surface erosion in the GyM vessel, using different wall materials (e.g. carbon, iron or tungsten) and applying different biasing voltage. Eroded particles are followed within the plasma to assess their redeposition location. The ionization probability of the different materials in the GyM plasma is inferred through the energy distribution of impacting particles and its effects on migration are investigated.
Effect of edge ion temperature on the divertor tungsten sputtering in WEST
Authors: Li Y. , Fedorczak N. , Xu G.S. , Liang Y. , Brezinsek S. , Morales J. 
Published: December 2022

Abstract
The influence of upstream ion temperature in the scrape-off layer (SOL) on the tungsten (W) sputtering in the divertor is studied in the WEST tokamak. For an almost constant power into the SOL, the upstream ion temperature and its ratio over the electron temperature gradually increase with the decrease of electron density in the SOL. This increment is observed to enhance the energy transfer from ions to electrons. This increases the downstream electron temperature and by coupling of electrons and ions, the impact energy of ions causing W sputtering in the divertor. This enhancement mechanism may become crucial to sputtering the W material for high upstream T
i/T
e ratio since the impact energy of ions in the divertor would increase accordingly.
Recent Progress in Quantum Key Distribution Network Deployments and Standards
Authors: Stanley M , Gui Y , Unnikrishnan D , Hall S.R.G , Fatadin I 
Published: December 2022

Abstract
Quantum key distribution (QKD) provides in principle unconditional security of key sharing based on the laws of physics only. In the last decade, several experimental and commercial QKD networks have been built and operated worldwide. Demonstrational applications of QKD in financial institutions, government networks, and critical infrastructures such as the power grid have been initially explored. However, large-scale deployment and full-scale commercialization of QKD networks still faces some technological and standardisation challenges. In this paper, recent developments and in-field deployments of QKD networks are reviewed and advancements in QKD standardisation are also discussed.
A novel ANN adaptive Riemannian-based kernel classification for motor imagery
Authors: Yacine Fodil , Salah Haddab , Amar Kachenoura , Ahmad Karfoul 
Published: December 2022

Abstract
More recently, a number of studies show the interest of the use of the Riemannian geometry in EEG classification. The idea is to exploit the EEG covariance matrices, instead of the raw EEG data, and use the Riemannian geometry to directly classify these matrices. This paper presents a novel Artificial Neural Network approach based on an Adaptive Riemannian Kernel, named ARK-ANN, to classify Electroencephalographic (EEG) motor imaging signals in the context of Brain Computer Interface (BCI). A multilayer perceptron is used to classify the covariance matrices of Motor Imagery (MI) signals employing an adaptive optimization of the testing set. The contribution of a geodesic filter is also assessed for the ANN and the original method which uses an SVM classifier. The results demonstrate that the ARK-ANN performs better than the other methods and the geodesic filter gives slightly better results in the ARK-SVM, considered here as the reference method, in the case of inter-subject classification (accuracy of 87.4% and 86% for ARK-ANN and ARK-SVM, respectively). Regarding the cross-subject classification, the proposed method gives an accuracy of 77.3% and increases the precision by 8.2% in comparison to the SVM based method.
Inferring directional interactions in collective dynamics: a critique to intrinsic mutual information
Authors: De Lellis Pietro , Ruiz Marín Manuel , Porfiri Maurizio 
Published: December 2022

Abstract
Pairwise interactions are critical to collective dynamics of natural and technological systems. Information theory is the gold standard to study these interactions, but recent work has identified pitfalls in the way information flow is appraised through classical metrics—time-delayed mutual information and transfer entropy. These pitfalls have prompted the introduction of intrinsic mutual information to precisely measure information flow. However, little is known regarding the potential use of intrinsic mutual information in the inference of directional influences to diagnose interactions from time-series of individual units. We explore this possibility within a minimalistic, mathematically tractable leader–follower model, for which we document an excess of false inferences of intrinsic mutual information compared to transfer entropy. This unexpected finding is linked to a fundamental limitation of intrinsic mutual information, which suffers from the same sins of time-delayed mutual information: a thin tail of the null distribution that favors the rejection of the null-hypothesis of independence.