bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validity and reliability of the International fItness scale (IFIS) in preschool children
Authors: Sánchez‐López Mairena , García‐Hermoso Antonio , Ortega Francisco B. , Moliner‐Urdiales Diego , Labayen Idoia , Castro‐Piñero Jose , Benito Pedro J. , Vicente‐Rodríguez Germán , Sanchis‐Moysi Joaquin , Cantallops Jaume , Artero Enrique G. , Martínez‐Vizcaíno Vicente 
Published: March 2022

ABSTRACTObjectives: Examine the validity and reliability of parent‐reported International FItness Scale (IFIS) in preschoolers. Method: A cross‐sectional study of 3051 Spanish preschoolers (3–5 years). Fitness was measured by PREFIT battery and reported by parents using an adapted version of the IFIS. Waist circumference was evaluated, and the waist‐to‐height ratio (WHtR) was calculated. Seventy‐six parents of randomly selected schoolchildren completed the IFIS twice for a reliability assessment. Results: ANCOVA, adjusted for sex, age and WHtR, showed that preschoolers who were scored by their parents as having average‐to‐very good fitness had better levels of measured physical fitness than those preschoolers who were classified as having “very poor/poor” fitness levels (18.1laps to 22.1laps vs 15.6laps for cardiorespiratory fitness; 6.6 kg to 7.5 kg vs 5.3 kg for muscular fitness‐handgrip‐; 71.7 cm to 76.4 cm vs 62.0 cm for muscular fitness‐standing long jump‐; 17.2s to 16.2s vs 18.2s for speed/agility; and 11.2s to 15.6s vs 8.7s for balance; p < 0.001). The weighted kappa for concordance between parent‐reported fitness levels and objective assessment was poor (κ ≤ 0.18 for all fitness measures). Overall, the mean values of the abdominal adiposity indicators were significantly lower in high‐level fitness categories reported by parents than in low‐level fitness categories (p < 0.05). The test‐retest reliability ranged from 0.46 to 0.62. Conclusions: The reliability of the parent‐reported IFIS are acceptable, but the concordance between parents reported and objectively measures fitness levels is poor, suggesting that parents’ responses may not be able to correctly classify preschoolers according to their fitness level.Highlights
The convergent validity and reliability (test‐retest) values of the IFIS parent scale are moderately acceptable for assessing physical fitness in children aged 3–5 years.
However, the results of concordance show that criterion validity is poor suggesting that parents’ responses may not be able to correctly classify preschoolers according to their fitness level.
Considering that the fitness level at these ages is fairly homogeneous, it seems difficult for parents to discriminate between the fitness levels of their children. Therefore, it seems necessary to recalibrate the scale in future work.
Exploring structural, electronic, optical, magnetic, and thermoelectric properties of Pt doped and Pt-Cu/Au co-doped GaN
Authors: Khan M Junaid Iqbal , Shakeel Mubashra , Majeed Iqra , Latif Abid , Ahmad Javed , Ullah Hamid , Fakhar-e-Alam M , Mustansar Zartasha , Asghar Mazia , Abdelmohsen Shaima A M 
Published: March 2022

AbstractWe present a computational research on investigating the structural, electronic, optical, magnetic, and thermoelectric properties of Pt doped and Pt-Cu/Au co-doped GaN using the Wien2k code. The PBE-GGA approximation is employed in Wien2k code using density functional theory. Study of electronic properties reveals that thed-states of Pt, Cu, and Au atoms participate actively in transferring electron from valence to conduction band and their addition as mono and co-doped formation turns the non-magnetic character of GaN to magnetic. A blueshift in absorption spectrum appear and absorption is more pronounced for Pt-Cu/Au co-doped GaN, suggesting the use of these materials for high energy UV optoelectronics, spintronics, photonic, and sensing devices. However, lower reflection and enhanced conductivity of Pt-Cu/Au co-doped materials in the UV region extends their potential applications in high frequency electronics. Moreover, higher ZT value of Pt@GaN suggest it a better thermoelectric source other than Pt-Cu/Au@GaN.
Robust optimal dispatch of integrated energy system considering with coupled wind and hydrogen system
Authors: Ding Liang , Gao Jie , Shi Guangnan , Ni Zihua 
Published: March 2022

Abstract
Hydrogen production from renewable energy will become one of the important features of the integrated energy system in the future. By considering the coupled wind and hydrogen system, it can not only take the advantages of fast power regulation of hydrogen energy, but improve the economy of wind and hydrogen system. In view of the high volatility of the wind power, this paper proposes a robust optimal scheduling model for integrated energy system considering with coupled wind and hydrogen system. Firstly, it establishes a comprehensive energy system model with wind and hydrogen system, forming an efficient electric-gas-electric energy closed-loop flow model with fuel cells. Then, based on improved multi-interval uncertainty sets, the model of wind turbines, electrical load and hydrogen load are described respectively, which can reduce the conservatism compared with the traditional robust optimization. And the two-stage robust optimal scheduling model is established and it can be solved by adopting Column and Constraint Generation method (C&CG). Finally, an example is given to verify the advantages of the proposed method.
Robust control-based power quality optimization strategy for inverters
Authors: Hu Changbin , Cheng Linshu , Luo Shanna , Yan Heming 
Published: March 2022

Abstract
A dynamic compensation control strategy based on a residual observer combined with a gradient descent optimization algorithm is proposed to address the power quality problem of distributed AC networks. The robust control structure based on the residual observer is designed according to the theory of Plug and Play control framework. The proposed structure is effective in improving the dynamic performance of the system without changing the structure and parameters. A gradient descent optimization algorithm is used to optimize the parameters of the rectified control structure online. Based on the need for fast response capability and stable performance of distributed grid systems, the gradient descent algorithm is optimized using the model matching principle, which provides a theoretical basis for the selection of initial points in the optimization algorithm. A low-order derivation form of the robust control structure is given through a step-down process to further enhance the speed of optimization under this strategy. The analysis shows that the strategy effectively enhances the robustness of the distributed grid system in comparison with the conventional double closed-loop control. Modelling simulation results verify the effectiveness of the proposed control strategy.
Study on High-precision Grid Outage Region Based on Distribution Network Topology Analysis
Authors: Yan Weikang , He Bing , Xie Tianxiang 
Published: March 2022

Abstract
Based on the recursion method and the Java language, this paper develops a program for analyzing the distribution network topology diagram and explores various scenarios of power outages. The power line topology analysis can pinpoint the power outage range, providing a solid foundation for power outage information release and distribution network reliability calculation.
Research on Time Delay Feedback Control of Lateral Vibration Axially Moving Viscoelastic Beam
Authors: Wang Bo , Tang Youqi 
Published: March 2022

Abstract
The nonlinear dynamic behavior of a viscoelastic beam in axially variable motion under time delay is studied. Considering that the axial velocity pulsation and radial tension change periodically with time under the action of time delay, the viscous damping and finite support stiffness are taken into account, and the viscoelastic constitutive relationship adopts Kelvin model. A mathematical model of lateral vibration of an axially moving viscoelastic beam with changes in axial velocity and tension under time delay is established, and a partial differential-integral control equation describing the lateral nonlinear vibration of an axially moving beam is given. Based on the Galerkin truncation method, the control equations established based on the mechanical model are discretized, so that the direct multi-scale method obtains the numerical solution of the lateral nonlinear vibration of the axially moving beam under the action of time delay, and determines the nonlinear dynamic behavior of the system under the action of time delay. By analyzing the numerical solution of the vibration displacement and velocity at the midpoint of the beam, the whole process of the average velocity of the axially moving structure along the axis, the amplitude of the disturbance tension and the change of the viscoelastic coefficient is simulated. It provides a numerical theoretical basis for the study of the nonlinear dynamic behavior of axially moving beams under time delay.
Through the research in this article, the introduction of time delay is studied, and the time delay is used to analyze the axial force that changes along the radial direction of the beam caused by the speed pulsation, and the theoretical framework for nonlinear vibration analysis of the axially moving viscoelastic beam is constructed to expand the time delay. The application scope of the nonlinear vibration theory and nonlinear dynamics theory, the development and improvement of the approximate analysis and numerical solution of the nonlinear continuum (especially the gyro body) under the action of time delay, to provide a theoretical basis for the analysis and design of the corresponding engineering system and technical reserves.
Numerical Simulation of RC Beams Subjected to Continuous Explosive Loading
Authors: Cao Guanjun , Yu Jinhuo 
Published: March 2022

Abstract
In order to study the performance of reinforced concrete (RC) beams Subjected to continuous explosive load, the numerical model of RC beam is established by LS-DYNA finite element program. And the numerical model experiences two explosive cases continuously. The reliability of the numerical model is verified by comparing with the field test results of a RC beam under the same explosive cases. It provides a reference for the future numerical simulation and experimental research of Building components under continuous explosive load.
Research on power system risk assessment considering large-scale wind and solar access
Authors: Pan Wei 
Published: March 2022

Abstract
The grid connection of new energy will bring some risks to the safe operation of power system. In this paper, the wind-output power model is established according to the wind-output characteristics, and the generator set, line and load probability models are established considering the uncertainty of other components of the system. From the perspective of power grid operation and new energy consumption, the traditional operation risk indexes such as voltage overrun and voltage collapse and the new wind and light abandoning indexes are selected, and the non-sequential Monte Carlo method is used to sample the operation state of the power system after wind and wind connecting to the grid, and the index is calculated. Finally, the influence of wind grid connection on system operation risk is analyzed to provide guidance for large-scale new energy grid operation risk assessment.
ZynqMP-based board-management mezzanines for Serenity ATCA-blades
Authors: Mehner T. , Ardila-Perez L.E. , Balzer M.N. , Sander O. , Tcherniakhovski D. , Schleicher M. , Fuchs M. , Fedi G. , Gimas G. , Iles G.M. , Pesaresi M. , Rose A.W. , Schuh T. 
Published: March 2022

Abstract
In the context of the CMS Phase-2 tracker back-end processing system, two mezzanines based on the Zynq Ultrascale+ Multi-Processor System-on-Chip (MPSoC) device have been developed to serve as centralized slow control and board management solution for the Serenity-family Advanced Telecommunications Computing Architecture (ATCA) blades. This paper presents the developments of the MPSoC mezzanines to execute the Intelligent Platform Management Controller (IPMC) software in the real-time capable processors of the MPSoC. In coordination with the Shelf Manager, once full-power is enabled, a CentOS-based Linux distribution is executed in the application processors of the MPSoC, on which EMPButler and the Serenity Management Shell (SMASH) are running.
Gait switching with phase reversal of locomotory waves in the centipede Scolopocryptops rubiginosus
Authors: Kuroda Shigeru , Uchida Nariya , Nakagaki Toshiyuki 
Published: March 2022

Abstract
Crawling using locomotory waves is a common method of locomotion for limbless and many-legged invertebrates and stimulates the biomimetic engineering of flexible locomotion. It is generally believed that the direction of locomotory waves is fixed for a given species. However, we found that a centipede, Scolopocryptops rubiginosus, flexibly generated its gait to allow for locomotory waves that varied in direction, depending on (i) locomotion speed and (ii) the physical conditions of terrain. We also found a new type of centipede’s swimming gait unlike eel-like way known so far which is using posteriorly traveling waves of horizontal body undulation. The gait patterns of the centipede were examined in various conditions and analyzed how the waves switched in detailed. We showed that gait patterns were associated with control of stride length rather than stride frequency. Discussion was made on a possible scenario of the gait transition in the centipede compatible with our observations. This finding may give a hint at bio-inspired control of flexible gait switching in response to irregular terrain.
Contrasting responses of forest growth and carbon sequestration to heat and drought in the Alps
Authors: Oddi Ludovica , Migliavacca Mirco , Cremonese Edoardo , Filippa Gianluca , Vacchiano Giorgio , Siniscalco Consolata , Morra di Cella Umberto , Galvagno Marta 
Published: March 2022

Abstract
Climate change is expected to increase both the frequency and the intensity of climate extremes, consequently increasing the risk of forest role transition from carbon sequestration to carbon emission. These changes are occurring more rapidly in the Alps, with important consequences for tree species adapted to strong climate seasonality and short growing season. In this study, we aimed at investigating the responses of a high-altitude Larix decidua Mill. forest to heat and drought, by coupling ecosystem- and tree-level measurements. From 2012 to 2018, ecosystem carbon and water fluxes (i.e. gross primary production, net ecosystem exchange, and evapotranspiration) were measured by means of the eddy covariance technique, together with the monitoring of canopy development (i.e. larch phenology and normalized difference vegetation index). From 2015 to 2017 we carried out additional observations at the tree level, including stem growth and its duration, direct phenological observations, sap flow, and tree water deficit. Results showed that the warm spells in 2015 and 2017 caused an advance of the phenological development and, thus, of the seasonal trajectories of many processes, at both tree and ecosystem level. However, we did not observe any significant quantitative changes regarding ecosystem gas exchanges during extreme years. In contrast, in 2017 we found a reduction of 17% in larch stem growth and a contraction of 45% of the stem growth period. The growing season in 2017 was indeed characterized by different drought events and by the highest water deficit during the study years. Due to its multi-level approach, our study provided evidence of the independence between C-source (i.e. photosynthesis) and C-sink (i.e. tree stem growth) processes in a subalpine larch forest.
Surface film deformation by melt moving in an alternating magnetic field and the integral criterion of such film stability
Authors: Nikulin I L , Demin V A , Perminov A V 
Published: March 2022

Abstract
The paper concerns some aspects of the induction melting technology improvement. The generalized mathematical model is presented which contains governing equations for the alternating magnetic field (AMF) diffusion into the liquid metal, heat and mass transfer in the melt and elastic deformation of the dielectric film covering partially the melt surface. The integral strain criterion is suggested which describes the total stress excited in the film by the melt motion. The model validation results are described. The influence of the film size on its stress–strain state is studied numerically for different values of external AMF frequency and strength. We calculate and classify realizable surface flow regimes depending on the AMF frequency and model, how this near-surface flow deforms the film of different sizes. An integral strain criterion is introduced, which lets to estimate the film break condition. The map of regimes is drawn which demonstrates the possible film radii at which the film does not break and does not deform depending on the AMF frequency and strength. It is shown, that integral strain criterion predicts well the film stress–strain state and conforms to the map of regimes. The results of numerical modeling, technique of the integral strain criterion calculation and examples of its application are given.
Arc-remodified long period fiber grating for monitoring absolute bending condition
Authors: Lu Chupeng , Wang Jiabin , Xu Xian , Rui Zeju , Xiang Zihang , Yan Qi , Geng Tao , Yuan Libo 
Published: March 2022

Abstract
In this paper, we propose an arc-remodified long period fiber grating (AR-LPFG) and introduce the ratios of shift-distance of two resonant dips (RSRDs) as a novel distinguishing index to monitor bending absolute condition which refers to detect the curvature and directions of fiber under a stationary status. The AR-LPFG is configured by arc-remodifying the LPFG that prepared from CO2 laser. The refractive index of the fiber is modulated again by the arc-remodification method which results in new resonant dips. Two orthogonal bending directions are distinguished by comparing the RSRDs, which are calculated to be 0.51 and 1.42 for 0° and 90°, respectively. Two opposite bending directions are distinguished by the opposite shift directions of two resonant dips. The stability and reliability of the novel distinguishing method are verified by a series of comparative experiments. The AR-LPFG still contains a conspicuous performance for bending variation sensing with a maximum sensitivity of 17.02 nm m−1. The AR-LPFG, together with the orientation distinguishing index, can be widely applied at the fields that the bending relative variation or absolute condition need to be monitored.
Mechanical performance evaluation of bamboo fibre reinforced polymer composites and its applications: a review
Authors: Nurazzi N M , Norrrahim M N F , Sabaruddin F A , Shazleen S S , Ilyas R A , Lee S H , Padzil F N M , Aizat G , Aisyah H A , Mohidem N A , Asyraf M R M , Abdullah N , Sapuan S M , Abdan K , Nor N M 
Published: March 2022

Abstract
This paper reviews the mechanical performance of bamboo fibre reinforced polymer composites (BFRPs) for structural applications. Bamboo fibres are very promising reinforcements for polymer composites production due to their high aspect ratio, renewability, environmentally friendly, non-toxicity, cheap cost, non-abrasives, full biodegradability, and strong mechanical performances. Besides, bamboo has its own prospects and good potential to be used in biopolymer composites as an alternative for petroleum-based materials to be used in several advanced applications in the building and construction industry. For bamboo fibre to be reinforced with polymer, they must have good interfacial bond between the polymer, as better fibre and matrix interaction results in good interfacial adhesion between fibre/matrix and fewer voids in the composite. Several important factors to improve matrix-fibre bonding and enhance the mechanical properties of BFRP are by fibre treatment, hybridisation, lamination, and using coupling agent. Moreover, mechanical properties of BFRP are greatly influenced by few factors, such as type of fibre and matrix used, fibre-matrix adhesion, fibre dispersion, fibre orientation, composite manufacturing technique used, void content in composites, and porosity of composite. In order to better understand their reinforcing potential, the mechanical properties of this material is critically discussed in this review paper. In addition, the advantages of bamboo fibres as the reinforcing phase in polymer composites is highlighted in this review paper. Besides that, the bamboo-based products such as laminated bamboo lumber, glued-laminated bamboo, hybrid bamboo polymer composites, parallel bamboo strand lumber, parallel strand bamboo, bamboo-oriented strand board, and bamboo-scrimber have lately been developed and used in structural applications.
Effect of cycling on ultra-thin HfZrO4, ferroelectric synaptic weights
Authors: Bégon-Lours Laura , Halter Mattia , Sousa Marilyne , Popoff Youri , Dávila Pineda Diana , Falcone Donato Francesco , Yu Zhenming , Reidt Steffen , Benatti Lorenzo , Puglisi Francesco Maria , Offrein Bert Jan 
Published: March 2022

Abstract
Two-terminal ferroelectric synaptic weights are fabricated on silicon. The active layers consist of a 2 nm thick WO
x
film and a 2.7 nm thick HfZrO4 (HZO) film grown by atomic layer deposition. The ultra-thin HZO layer is crystallized in the ferroelectric phase using a millisecond flash at a temperature of only 500 °C, evidenced by x-rays diffraction and electron microscopy. The current density is increased by four orders of magnitude compared to weights based on a 5 nm thick HZO film. Potentiation and depression (analog resistive switching) is demonstrated using either pulses of constant duration (as short as 20 nanoseconds) and increasing amplitude, or pulses of constant amplitude (+/−1 V) and increasing duration. The cycle-to-cycle variation is below 1%. Temperature dependent electrical characterisation is performed on a series of device cycled up to 108 times: they reveal that HZO possess semiconducting properties. The fatigue leads to a decrease, in the high resistive state only, of the conductivity and of the activation energy.