bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainty quantification for aerodynamic pressure probes, using adaptive quasi-Monte Carlo
Authors: Chasoglou A C , Tsirikoglou P , Kalfas A I , Abhari R S 
Published: December 2021

Abstract
In the present study, an adaptive randomized Quasi Monte Carlo methodology is presented, combining Stein’s two-stage adaptive scheme and Low Discrepancy Sobol sequences. The method is used for the propagation and calculation of uncertainties related to aerodynamic pneumatic probes and high frequency fast response aerodynamic probes (FRAP) in the subsonic flow regime,

0.15
⩽
M
⩽
0.7

. The use of the proposed methodology allows the fast and accurate, in a probabilistic sense, calculation of uncertainties, ensuring that the total number of Monte Carlo (MC) trials is kept low based on the desired numerical accuracy. Thus, the method is well-suited for aerodynamic pressure probes, where multiple points need to be evaluated in their calibration space. Complete and detailed measurement models are presented for both a pneumatic probe and FRAP. The models are segregated in sub-problems that allow the evaluation and inspection of intermediate steps of MC in a transparent manner, also enabling the calculation of the relative contributions of the elemental uncertainties on the measured quantities. The adaptive scheme is implemented with a block-to-block evaluation, which accelerates the calculation of statistical parameters. Various, commonly-used sampling techniques for MC simulation and different adaptive MC schemes are compared, using both theoretical toy distributions and actual examples from aerodynamic probes’ measurement models. The robustness of Stein’s two-stage scheme is demonstrated even in cases when significant deviation from normality is observed in the underlying distribution of the output of the MC. With regards to FRAP, two issues related to piezo-resistive sensors are addressed, namely temperature dependent pressure hysteresis and temporal sensor drift, and their uncertainties are accounted for in the measurement model. These effects are the most dominant factors, affecting all flow quantities’ uncertainties, with significance that varies mainly with M and operating temperature. This work highlights the need to construct accurate and detailed measurement models for aerodynamic probes, that otherwise will result in significant underestimation (routinely in excess of 50

%

) of the final uncertainties.
A boundary division guiding synchrosqueezed wave packet transform method for rolling bearing fault diagnosis
Authors: Pang Bin , Zhang Heng , Sun Zhenduo , Yan Xiaoli , Li Chunhua , Tang Guiji 
Published: December 2021

Abstract
Synchrosqueezed wave packet transform (SSWPT) can effectively reconstruct the band-limited components of the signal by inputting the specific reconstructed boundaries, and it provides an alternative bearing fault diagnosis method. However, the selection of reconstructed boundaries can significantly affect the fault feature extraction performance of SSWPT. Accordingly, this paper presents a boundary division guiding SSWPT (BD-SSWPT) method. In this method, an adaptive boundary division method is developed to effectively determine the reconstructed boundaries of SSWPT. Firstly, the marginal spectrum of SSWPT, more robust to noise than the Fourier spectrum, is defined for the scale-space division to obtain the initial boundaries. Secondly, the inverse transform of SSWPT is conducted based on the initial boundaries to obtain the initial reconstructed components. Thirdly, a boundary redefinition scheme, composed of clustering and combination, is conducted to redefine the boundaries. Finally, the potential components are extracted by the inverse transform of SSWPT based on the redefined boundaries. The validity of BD-SSWPT is verified by simulated and experimental analysis, and the superiority of BD-SSWPT is highlighted through comparison with singular spectrum decomposition (SSD) and an adaptive parameter optimized variational mode decomposition (AVMD). The results demonstrate that BD-SSWPT identifies more significant fault features and has higher computational efficiency than SSD and AVMD.
Dislocation evolution during additive manufacturing of tungsten
Authors: Cui Yinan , Li Kailun , Wang Chan , Liu Wei 
Published: December 2021

Abstract
Additive manufacturing (AM) frequently encounters part quality issues such as geometrical inaccuracy, cracking, warping, etc. This is associated with its unique thermal and mechanical cycling during AM, as well as the material properties. Although many efforts have been spent on this problem, the underlying dislocation evolution mechanism during AM is still largely unknown, despite its essential role in the deformation and cracking behavior during AM and the properties of as-fabricated parts. In this work, a coupling method of three-dimensional dislocation dynamics and finite element method is established to disclose the mechanisms and features of dislocations during AM. Tungsten (W) is chosen as the investigated material due to its wide application. The internal thermal activated nature of dislocation mobility in W is taken into account. The correlations between the combined thermal and mechanical cycles and dislocation evolutions are disclosed. The effect of adding alloying element Ta in W is discussed from the perspectives of tuning dislocation mobility and introducing nanoparticles, which helps to understand why higher dislocation density and fewer microcracks are observed when adding Ta. The current work sheds new light on the long-standing debating of dislocation origin and evolutions in the AM field.
Nanoscale self-assembly: concepts, applications and challenges
Authors: Amadi Eberechukwu Victoria , Venkataraman Anusha , Papadopoulos Chris 
Published: December 2021

Abstract
Self-assembly offers unique possibilities for fabricating nanostructures, with different morphologies and properties, typically from vapour or liquid phase precursors. Molecular units, nanoparticles, biological molecules and other discrete elements can spontaneously organise or form via interactions at the nanoscale. Currently, nanoscale self-assembly finds applications in a wide variety of areas including carbon nanomaterials and semiconductor nanowires, semiconductor heterojunctions and superlattices, the deposition of quantum dots, drug delivery, such as mRNA-based vaccines, and modern integrated circuits and nanoelectronics, to name a few. Recent advancements in drug delivery, silicon nanoelectronics, lasers and nanotechnology in general, owing to nanoscale self-assembly, coupled with its versatility, simplicity and scalability, have highlighted its importance and potential for fabricating more complex nanostructures with advanced functionalities in the future. This review aims to provide readers with concise information about the basic concepts of nanoscale self-assembly, its applications to date, and future outlook. First, an overview of various self-assembly techniques such as vapour deposition, colloidal growth, molecular self-assembly and directed self-assembly/hybrid approaches are discussed. Applications in diverse fields involving specific examples of nanoscale self-assembly then highlight the state of the art and finally, the future outlook for nanoscale self-assembly and potential for more complex nanomaterial assemblies in the future as technological functionality increases.
Quantum computing for classical problems: variational quantum eigensolver for activated processes
Authors: Pravatto Pierpaolo , Castaldo Davide , Gallina Federico , Fresch Barbara , Corni Stefano , Moro Giorgio J 
Published: December 2021

Abstract
The theory of stochastic processes impacts both physical and social sciences. At the molecular scale, stochastic dynamics is ubiquitous because of thermal fluctuations. The Fokker–Plank–Smoluchowski equation models the time evolution of the probability density of selected degrees of freedom in the diffusive regime and it is, therefore, a workhorse of physical chemistry. In this paper we report on the development and implementation of a variational quantum eigensolver to solve the Fokker–Planck–Smoluchowski eigenvalue problem. We show that such an algorithm, typically adopted to address quantum chemistry problems, can be effectively applied to classical systems, paving the way to new applications of quantum computers. We compute the conformational transition rate in a linear chain of rotors with nearest-neighbour interactions. We provide a method to encode the probability distribution for a given conformation of the chain on a quantum computer and assess its scalability in terms of operations. A performance analysis on noisy quantum emulators and quantum devices (IBMQ Santiago) is provided for a small chain which shows results in good agreement with the classical benchmark without any further addition of error mitigation techniques.
Identify spin property of relativistic electrons in fully relativistic laser fields
Authors: Li X B , Gan L F , Wang J , Jiao J L , Jin S , Zhuo H B , Zhou C T , Zhu S P , He X T , Qiao B 
Published: December 2021

Abstract
A semiclassical method is developed to study the spin evolution of a relativistic electron in an fully relativistic laser pulse. Different from the previous classical method which is based on the direct generalization of nonrelativistic spin precession equation, we perform first-principle calculations on the mean values of various spin operators with respect to a relativistic electron wave packet. It is demonstrated, via theoretical derivation and numerical simulation, that although the Foldy–Wouthuysen operator merits the single-particle interpretation, its mean value obviously deviates from the result of the classical method, which sheds light on not only the understanding of relativistic spin itself but also broad related applications. To achieve a direct observation of such effect, a feasible experimental setup utilizing the asymmetric field of a single-cycle laser is proposed. In such geometry, the deviation is evidenced in the total change of spin which can be easily measured after the interaction.
Multiple Fano resonances based on clockwork spring-shaped resonator for refractive index sensing
Authors: Ding Jinghui , Qi Yunping , Yuan Yujiao , Chen Haowen , Liu Weiming , Jia Yingjun , Wang Xiangxian 
Published: December 2021

Abstract
A surface plasmon polarized structure consisting of two metal-insulator-metal (MIM) waveguide coupled with clockwork spring-shaped resonators are constructed in this paper, and its geometric parameters are controlled within a few hundred nanometers. The finite element method (FEM) and multimode interference coupled mode theory (MICMT) are used to simulate and theoretically calculate the optical response of the designed structure. By modifying the structural parameters of the system, the influence on the asymmetry of the Fano resonance line is studied. The changes of the transmission spectra at different refractive indexes are also investigated. Based on this asymmetric resonant line, the sensitivity and FOM* (figure of merit) value of the cavity with different parameters are measured. The sensitivity and FOM* under the best parameters are 1200 nm RIU−1 and 191.6, respectively. The surface plasmon structure proposed and the results in this paper are promising for applications in the field of high-performance sensing and micro-nano optical devices.
Cluster decay half-lives using asymmetry dependent densities
Authors: Dehghani V. , Alavi S. A. , Razavi R. , Soylu A. , Koyuncu F. 
Published: December 2021

Abstract
By adopting different neutron and proton density distributions, cluster decay half-lives were investigated using double-folding potentials with constant and nuclear asymmetry dependent sets of nuclear density parameters. Two adopted asymmetry dependent sets of parameters were fitted based on microscopic calculations, and they were calculated based on the neutron skin/halo-type nuclei assumption and by employing experimental rms charge radii. A bulk agreement between theory and experiment was obtained for all sets of parameters using a calculated cluster preformation probability. Few differences were observed between the skin and halo-type assumptions. However, the notable role of the asymmetry parameter was observed in the relatively large differences between the skin and skin-type with zero thickness.
Optimizing a left and right visual field biphasic stimulation paradigm for SSVEP-based BCIs with hairless region behind the ear
Authors: Liang Liyan , Bin Guangyu , Chen Xiaogang , Wang Yijun , Gao Shangkai , Gao Xiaorong 
Published: December 2021

Abstract

Objective. Steady-state visual evoked potential (SSVEP) based brain–computer interface (BCI) has the characteristics of fast communication speed, high stability, and wide applicability, thus it has been widely studied. With the rapid development in paradigm, algorithm, and system design, SSVEP-BCI is gradually applied in clinical and real-life scenarios. In order to improve the ease of use of the SSVEP-BCI system, many studies have been focusing on developing it on the hairless area, but due to the lack of redesigning the stimulation paradigm to better adapt to the new area, the electroencephalography response in the hairless area is worse than occipital region. Approach. This study first proposed a phase difference estimation method based on stimulating the left and right visual field separately, then developed and optimized a left and right visual field biphasic stimulation paradigm for SSVEP-based BCIs with hairless region behind the ear. Main results. In the 12-target online experiment, after a short model estimation training, all 16 subjects used their best stimulus condition. The paradigm designed in this study can increase the proportion of applicable subjects for the behind-ear SSVEP-BCI system from 58.3% to 75% and increase the accuracy from 74.6 ± 20.0% (the existing best SSVEP stimulus with hairless region behind the ear) to 84.2

±

14.7%, and the information transfer rate from 14.2

±

6.4 bits min−1 to 17.8

±

5.7 bits min−1. Significance. These results demonstrated that the proposed paradigm can effectively improve the BCI performance using the signal from the hairless region behind the ear, compared with the standard SSVEP stimulation paradigm.
Ion heating and energy balance during magnetic reconnection events in the RFX-mod experiment
Authors: Gobbin M. , Agostini M. , Auriemma F. , Carraro L. , Cavazzana R. , Fassina A. , Franz P. , Marrelli L. , Momo B. , Piovan R. , Predebon I. , Puiatti M.E. , Spizzo G. , Terranova D. , Zuin M. , RFX-mod Team  
Published: December 2021

Abstract
Reconnection events in high current reversed field pinch plasmas are often associated to the partial or total loss of the helical magnetic topology. The electron temperature collapse during these phenomena is investigated in RFX-mod thanks to high time resolution soft-x-ray diagnostics; these data are used, together with magnetic energy reconstructions, for energy balance analysis. The paper shows that the energy released during reconnection events, similarly to astrophysical plasmas, might be involved in ion heating, the latter being estimated by the energy distribution function of neutral atoms, a rather interesting feature in a reactorial perspective. These issues will be further investigated in RFX-mod2 , an upgrade of the present device starting its operations from 2022, where the modified boundary conditions are expected to increase the helical states duration and reduce the frequency of reconnection events.
Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme
Authors: Bonofiglo P.J. , Podestà M. , White R.B. , Kiptily V. , Goloborodko V. , Gorelenkov N.N. , Vallar M. , Cecil F.E. , Giroud C. , Brezinsek S. , JET Contributors  
Published: December 2021

Abstract
An integrated energetic particle transport model has been constructed in JET plasmas constrained by experimental fast ion loss measurements. The model incorporates a synthetic fast ion loss detector identical to JET’s thin-foil Faraday cup fast ion loss detector array. The loss model combines analyses from the TRANSP and ORBIT-kick codes with enhanced features for producing the synthetic diagnostic. Extensions to the ORBIT code framework allow a full-orbit representation within the vacuum region that can map particles directly to an installed detector geometry. Since synthetic fast ion loss detectors are plagued by weak loss statistics, a novel reverse integration biasing scheme has been implemented to boost computational efficiency. The model is validated against experimental loss measurements induced by long-lived kink modes and is found to be in good agreement. This confirms the development of a fully integrated transport/loss model which can be quantitatively verified against experiment allowing for future validation and predictive studies. The model is particularly useful for more complicated plasma scenarios that involve multiple fast ion species such as JET’s 2021 DT-campaign.
Low-frequency zonal flow eigen-structures in tokamak plasmas
Authors: Ilgisonis V.I. , Lakhin V.P. , Marusov N.A. , Smolyakov A.I. , Sorokina E.A. 
Published: December 2021

Abstract
The nonlocal eigenmode analysis of low-frequency zonal flows (ZFs) in toroidally rotating tokamak plasmas is performed in the framework of the reduced one-fluid ideal magnetohydrodynamic model. It is shown that for typical profiles of plasma parameters toroidal plasma rotation results in the global ZF formation on the periphery of plasma column. For some types of equilibria these ZFs are aperiodically unstable that leads to the excitation of the differential plasma rotation at the tokamak plasma edge.
Zonal flow generation and toroidal Alfvén eigenmode excitation due to tearing mode induced energetic particle redistribution
Authors: Zhang H.W. , Ma Z.W. , Zhu J. , Zhang W. , Qiu Z.Y. 
Published: December 2021

Abstract
Generation of the n = 0 zonal flow and excitation of the n = 1 toroidal Alfvén eigenmode (TAE) due to the redistribution of energetic particles (EPs) by the m/n = 2/1 tearing mode (TM) are systematically studied with the hybrid drift-kinetic magnetohydrodynamic (MHD) simulations (m and n represent the poloidal and toroidal mode number, respectively). In the presence of the m/n = 2/1 TM, the amplitude of the n = 1 TAE shows a slower decay after its first saturation due to the wave–particle nonlinearity and the nonlinear generation of the n = 0 & higher-n (n ⩾ 2) sidebands. Meanwhile, a strong n = 0 zonal flow component is nonlinearly generated when both TAE and TM grow to large amplitudes. The redistribution of EPs by the m/n = 2/1 magnetic island results in a continuous drive on the background plasma, and finally produces the zonal flow through the MHD nonlinearity. In addition, the large m/n = 2/1 magnetic island is found to be responsible for the formation of the strong spatial gradient of the EP distribution through the resonance between EPs and TM, which can lead to burst of unstable TAE and destabilization of originally stable TAE.
Monitoring the brightness temperature of the Moon throughout the lunar cycle from radio observations in the Ku band
Authors: Galeano David , Edwin A. Quintero 
Published: December 2021

Abstract
Within the spectrum of radio waves, the Ku band (12 - 18 GHz
) stands out for the wide range of instruments available and for its relative ease of acquisition, given that satellite television operates in this band. This situation offers a great opportunity for the development of radio astronomy in countries with unfavorable climatic conditions for optical astronomy, since this band is only affected by dense masses of water vapor. In this article we present a methodology for the calibration of the receiver system of compact Ku-band radio telescopes, and its application in the determination of the brightness temperature of the Moon. Our methodology involves modeling the influence of the atmosphere of the Earth on the response of the radioreceptor, which minimizes the error in the calculation of the brightness temperature of the observed object. We applied the proposed methodology in the monitoring of the Lunar cycle using the Ku-band radio telescope of the Observatorio Astronomico of Universidad Tecnológica de Pereira, Colombia (OAUTP). After observing during May, June, and July of 2021, we obtained an average temperature of 213.15 K, with maximum and minimum values of 275.55 K and 150.75 K, respectively. In addition, we evidenced a delay of 5.75 days between the phase in which the maximum temperature is presented and the phase of the full Moon, which is consistent with the frequency of observation. The results show that our methodology is useful to optimize the calibration of compact Ku-band radio telescopes, and expand the potential of this type of instrument for the scientific study of radio sources other than the Sun, in this case the Moon.
Dipole Polarizability of C28and its Counterparts Nb4B18and Ta4B18. Insights from a Density Functional Theory (DFT) Endeavour
Authors: Xenides Demetrios , Karamanis Panaghiotis 
Published: December 2021

AbstractWe report on a preliminary investigation of the non linear optical (NLO) properties and in particular dipole polarizability. The target species are two perfect tetrahedral nanoclusters Nb4B18and Ta4B18, along with their nanofullerene counterpart that is C28. Our study based on density functionals (DFs) that have gained popularity among the scientific community. In addition we performed Hartree-Fock calculations known for not including dynamic electron correlation. The DF obtained values are characterized by some dispersion, with maximal differences to be around 5 %, in all three cases. Given that the DFT introduces a fuzzy percentage of electron correlation sets the observed convergence of HF values to DFT ones is at least surprising. Furthermore, it should be said that though the values can be characterized as accurate their reliability should not be taken for granted. Last, we note the smooth convergence of LC-BLYP, LC-BP86, LC-BPW91 to LC-whPBE.
Effectiveness of using The GeoEnzo Application on Metacognitive Abilities in Mathematics Learning
Authors: Syamsuddin  , Latif Abdul , Ahmad Herlina , Febryanti  
Published: December 2021

Abstract
This research is an experimental study that aims to determine the effectiveness of using the GeoEnzo application. The subjects in this study were students of class XII SMK Mega Link Majene. The research instrument was used to reveal students’ metacognitive abilities in understanding and solving problems on three-dimensional material. The instruments used were tests, observation sheets, and student response questionnaires. The data analysis used was descriptive and inferential statistical analysis. The results of the analysis showed that the average value of students’ metacognitive abilities in understanding the material was 82.75 in the high category, while the metacognitive ability in solving questions was 85.25 in the high category. Student activities are in the very active category and student responses to learning give a very positive response. The t-test shows the sig value. (2-tailed) = 0.000 < α = 0.05, thus the application of GeoEnzo application media is effective for students’ metacognitive abilities in mathematics learning.