bluuebunny/crossref_metadata_2025 huggingface dataset:
Tensile twin evolution of Mg–3Al–1Zn magnesium alloy during high-strain rate deformation
Authors: Chen Yang , Mao Pingli , Wang Zhi , Cao Gengsheng
Published: December 2021

In order to investigate the evolution of [Formula: see text] tensile twin in Mg–3Al–1Zn (AZ31) magnesium alloy under high-strain rate impaction, the cylindrical specimens were compressed along the rolling direction under the strain rate of 1600 s−1 by use of split Hopkinson pressure bars equipped with stop rings with different thicknesses. The microstructure was observed by electron back-scatter diffraction. The results show that [Formula: see text] tensile twinning dominates the early plastic deformation and the area fraction of [Formula: see text] tensile twins is increased with the increase of deformation strain. Furthermore, when the deformation strain is beyond ∼10%, plastic deformation is mainly dominated by dislocation slips. In addition, most of [Formula: see text] tensile twins activated in a single grain belong to a variant or a variant pair, which has the highest Schmid factor among all the variants.
Modeling human yolk sac hematopoiesis with pluripotent stem cells
Authors: Atkins Michael H. , Scarfò Rebecca , McGrath Kathleen E. , Yang Donghe , Palis James , Ditadi Andrea , Keller Gordon M.
Published: December 2021

In the mouse, the first hematopoietic cells are generated in the yolk sac from the primitive, erythro-myeloid progenitor (EMP) and lymphoid programs that are specified before the emergence of hematopoietic stem cells. While many of the yolk sac–derived populations are transient, specific immune cell progeny seed developing tissues, where they function into adult life. To access the human equivalent of these lineages, we modeled yolk sac hematopoietic development using pluripotent stem cell differentiation. Here, we show that the combination of Activin A, BMP4, and FGF2 induces a population of KDR+CD235a/b+ mesoderm that gives rise to the spectrum of erythroid, myeloid, and T lymphoid lineages characteristic of the mouse yolk sac hematopoietic programs, including the Vδ2+ subset of γ/δ T cells that develops early in the human embryo. Through clonal analyses, we identified a multipotent hematopoietic progenitor with erythroid, myeloid, and T lymphoid potential, suggesting that the yolk sac EMP and lymphoid lineages may develop from a common progenitor.
Improved effective dynamics of loop-quantum-gravity black hole and Nariai limit
Authors: Han Muxin , Liu Hongguang
Published: December 2021

We propose a new model of the spherical symmetric quantum black hole in the reduced phase space formulation. We deparametrize gravity by coupling to the Gaussian dust which provides the material coordinates. The foliation by dust coordinates covers both the interior and exterior of the black hole. After the spherical symmetry reduction, our model is a 1 + 1 dimensional field theory containing infinitely many degrees of freedom. The effective dynamics of the quantum black hole is generated by an improved physical Hamiltonian H
Δ. The holonomy correction in H
Δ is implemented by the

μ

¯

-scheme regularization with a Planckian area scale Δ (which often chosen as the minimal area gap in loop quantum gravity). The effective dynamics recovers the semiclassical Schwarzschild geometry at low curvature regime and resolves the black hole singularity with Planckian curvature, e.g. R

μνρσ

R

μνρσ
∼ 1/Δ2. Our model predicts that the evolution of the black hole at late time reaches the charged Nariai geometry dS2 × S
2 with Planckian radii

∼

Δ

. The Nariai geometry is stable under linear perturbations but may be unstable by nonperturbative quantum effects. Our model suggests the existence of quantum tunneling of the Nariai geometry and a scenario of black-hole-to-white-hole transition.
Deepening of domains at e-beam writing on the −Z surface of lithium niobate
Authors: Kokhanchik L S , Emelin E V , Sirotkin V V , Svintsov A A
Published: December 2021

The focus of this study was to investigate the peculiarities of the domains created by an electron beam (e-beam) in a surface layer of congruent lithium niobate (LiNbO3, LN), which are comparable to the depth of e-beam charge penetration. Direct e-beam writing (DEBW) of different domain structures with a scanning electron microscope was performed on the polar −Z cut. Accelerating voltage 15 kV and e-beam current 100 pA were applied. Different patterns of local irradiated squares were used to create domain structures and single domains. No domain contrast was observed by the piezoelectric force microscopy technique. Based on chemical etching, it was found that the vertices of the domains created do not reach the surface level. The average deepening of the domain vertices was several hundred nanometers and varied depending on the irradiation dose and the locations of the irradiated areas (squares) relative to each other. Computer simulation was applied to analyze the spatial distribution of the electric field in the various irradiated patterns. The deepening was explained by the fact that in the near-surface layer there is a sign inversion of the normal component of the electric field strength vector, which controls the domain formation during DEBW. Thus, with the help of the e-beam, domains were created completely located in the bulk, in contrast to the domains that are nucleated on the surface of the −Z cut during polarization inversion with an atomic force microscope tip. The detected deepening of e-beam domains suggests the possibility of creating ‘head-to-head’ domain walls in near-surface-layer LN by DEBW.
Printed dual-gate organic thin film transistors and PMOS inverters on flexible substrates: role of top gate electrode
Authors: Singh Subhash , Matsui Hiroyuki , Tokito Shizuo
Published: December 2021

We report printed single and dual-gate organic thin film transistors (OTFTs) and p-channel metal-oxide-semiconductor (PMOS) inverters fabricated on 125 µm thick flexible polyethylene naphthalate substrate. All the electrodes (gate, source, and drain) are inkjet-printed, while the parylene dielectric is formed by chemical vapor deposition. A dispenser system is used to print the active channel material using a blend of 2,7-dihexyl-dithieno[2,3-d;2′,3′-d′]benzo [1,2-b;4,5-b′]dithiophene and polystyrene in tetralin solvent, which gives highest mobility of 0.43 cm2 V−1s−1. Dual-gate OTFTs are characterized by keeping the other gate electrode either in grounded or floating state. Floating gate electrode devices shows higher apparent mobility and current ratio due to additional capacitance of the parylene dielectric. PMOS inverter circuits are characterized in terms of gain, trip point and noise margin values calculated from the voltage transfer characteristics (VTC). Applied top gate voltage on the load OTFT control the conductivity or threshold voltage (V
Th) of the bottom TFT and shift the trip point towards the middle of the VTC curve, and hence increase the noise margin.
Investigation of field-controlled magnetocaloric switching and magnetodielectric phenomena in spin-chain compound Er2BaNiO5
Authors: Pal Arnab , Feng Zhenjie , Wu Hao , Wang Ke , Si Jingying , Chen Jiafeng , Chen Yanhong , Zhang Yifeng , Chen Fei , Ge Jun-Yi , Cao Shixun , Zhang Jincang
Published: December 2021

The Haldane spin-chain compound Er2BaNiO5 has been known to possess magnetoelectric coupling below the magnetic ordering temperature. Here we report various low-temperature magnetic and magnetocaloric properties, and magnetodielectric (MD) effect above magnetic ordering temperature in this compound. The present compound displays a coexistence of conventional and inverse magnetocaloric effects with a large entropy change of 5.9 and −2.5 J kg−1 K−1, respectively. Further, it exhibits a remarkable switching between them, which can be tuned with temperature and magnetic field. In addition, evolution of two magnetic field-dependent metamagnetic transitions at 19.7 and 27.7 kOe, and their correlation with magnetocaloric switching effect, make this compound effective for potential applications. On the other hand, demonstration of intrinsic MD effect (1.9%) near and above antiferromagnetic ordering temperature, through a moderate coupling between electric dipoles and magnetic spins, establishes this compound as a useful candidate for future research. A detailed analysis of these findings, in a framework of different magnetic interactions and magnetocrystalline anisotropies, is discussed here. Overall, these results may provide a future pathway to tune the magnetic, MD, and magnetocaloric properties in this compound toward better application potential.
Prediction of the irradiation doses from ultrashort laser-solid interactions using different temperature scalings at moderate laser intensities
Authors: Barkauskas V , Plukis A
Published: December 2021

The ionising radiation created by high intensity and high repetition rate lasers can cause significant radiological hazard. Earlier defined electron temperature scalings are used for dose characterisation and prediction using Monte Carlo modelling. Dosimetric implications of different electron temperature scalings are investigated and the resulting equivalent doses are compared. It was found that scaling defined by Beg et al (1997 Phys. Plasmas
4 447–57) predicts the highest electron temperatures for given intensities, and subsequently the highest doses. The atomic number of the target, x-ray generation efficiency and interaction volume are the other parameters necessary for the dose evaluation. The set of these operational parameters should be sufficient to characterise radiological characteristics of ultrashort laser pulse based x-ray generators and evaluate radiological hazards of the laser processing facilities.
Dislocation transport using a time-explicit Runge–Kutta discontinuous Galerkin finite element approach
Authors: Upadhyay Manas Vijay , Bleyer Jérémy
Published: December 2021

A time-explicit Runge–Kutta discontinuous Galerkin (RKDG) finite element scheme is proposed to solve the dislocation transport initial boundary value problem in 3D. The dislocation density transport equation, which lies at the core of this problem, is a first-order unsteady-state advection–reaction-type hyperbolic partial differential equation; the DG approach is well suited to solve such equations that lack any diffusion terms. The development of the RKDG scheme follows the method of lines approach. First, a space semi-discretization is performed using the DG approach with upwinding to obtain a system of ordinary differential equations in time. Then, time discretization is performed using explicit RK schemes to solve this system. The 3D numerical implementation of the RKDG scheme is performed for the first-order (forward Euler), second-order and third-order RK methods using the strong stability preserving approach. These implementations provide (quasi-)optimal convergence rates for smooth solutions. A slope limiter is used to prevent spurious Gibbs oscillations arising from high-order space approximations (polynomial degree ⩾ 1) of rough solutions. A parametric study is performed to understand the influence of key parameters of the RKDG scheme on the stability of the solution predicted during a screw dislocation transport simulation. Then, annihilation of two oppositely signed screw dislocations and the expansion of a polygonal dislocation loop are simulated. The RKDG scheme is able to resolve the shock generated during dislocation annihilation without any spurious oscillations and predict the prismatic loop expansion with very low numerical diffusion. These results indicate that the proposed scheme is more robust and accurate in comparison to existing approaches based on the continuous Galerkin finite element method or the fast Fourier transform method.
Highly anisotropic thermal conductivity and electrical insulation of nanofibrillated cellulose/Al2O3@rGO composite films: effect of the particle size
Authors: Ma Meng , Chu Qindan , Lin Hao , Xu Lin , He Huiwen , Shi Yanqin , Chen Si , Wang Xu
Published: December 2021

Nanofibrillated cellulose (NFC) film has received tremendous attention due to its excellent electrical insulation, which shows great application prospects in the field of electronic devices. However, the low efficient heat dissipation of NFC film largely limits its use in advanced applications. In this work, the reduced graphene oxide hybrid fillers loaded alumina (Al2O3) particles with different sizes were synthesized by different drying methods, and then they were mixed with NFC to prepare a series of NFC-based composite films. The effect of Al2O3 particle sizes on the thermal conductivity of NFC-based composite films was studied. The results showed that the surface areas of l-Al2O3 particles were smaller than that of s-Al2O3 particles, resulting in the smaller interface thermal resistance and superior thermal conductivity of the film containing l-Al2O3 particles. The NFC-based composite films showed great potential for applications in thermal management by adjusting the particle size of fillers.
Efficient oxygen evolution reaction on RuO2 nanoparticles decorated onion-like carbon (OLC)
Authors: Zhang Liyun , Gan Xingyu , Zhong Xia , Wang Lihua , Feng Guangjing , Wang Lei , Wang Yongzhao , Lv Xiaoxia , Zhu Wancheng , Zhang Bingsen
Published: December 2021

Oxygen evolution reaction (OER) is an important half-cell reaction of the electrical water splitting, for its high overpotential associated with sluggish OER kinetics. Therefore, it is critical to develop highly active and durable electrocatalysts to reduce the overpotential. Herein, ultra-small RuO2 nanoparticles (NPs) supported on onion-like carbon (OLC) and carbon nanotube (CNT) are successfully synthesized by means of wet impregnation combined with annealing treatment, respectively. The microstructure characterization results showed OLC perfect graphitic carbon layer structure, and the RuO2 NPs supported on the OLC possess larger particle size compared with the RuO2 NPs supported on the CNT. Moreover, the electronic structure of Ru in RuO2/OLC was also optimized by the OLC support to be beneficial for the OER. The OER performance of the catalysts were investigated in 1 M KOH solution. The results show RuO2/OLC has a comparable OER activity to the commercial RuO2, but a significantly higher mass activity than the commercial RuO2. When compared with the RuO2/CNT, RuO2/OLC not only exhibits lower overpotential and Tafel slop, but also owns more active sites and higher TOF value, indicating the OLC support improved the OER activity of RuO2/OLC. Moreover, RuO2/OLC showed a superior stability compared with RuO2/CNT, which can be attributed to the excellent electrochemical oxidation-resistance of the OLC.
Block copolymer self-assembly assisted fabrication of laterally organized- and stacked- nanoarrays
Authors: Suresh Vignesh , Chew Ah Bian , Tan Christina Yuan Ling , Tan Hui Ru
Published: December 2021

Block copolymer (BCP) self-assembly processes are often seen as reliable techniques for advanced nanopatterning to achieve functional surfaces and create templates for nanofabrication. By taking advantage of the tunability in pitch, diameter and feature-to-feature separation of the self-assembled BCP features, complex, laterally organized- and stacked- multicomponent nanoarrays comprising of gold and polymer have been fabricated. The approaches not only demonstrate nanopatterning of up to two levels of hierarchy but also investigate how a variation in the feature-to-feature gap at the first hierarchy affects the self-assembly of polymer features at the second. Such BCP self-assembly enabled multicomponent nanoarray configurations are rarely achieved by other nanofabrication approaches and are particularly promising for pushing the boundaries of block copolymer lithography and in creating unique surface architectures and complex morphologies at the nanoscale.
Constructing zigzag-like hollow mesoporous nanospheres MoO2/C with superior lithium storage performance
Authors: Zhao Wencai , Yuan Yongfeng , Yin Simin , Cai Gaoshen , Guo Shaoyi
Published: December 2021

Hollow mesoporous nanospheres MoO2/C are successfully constructed through metal chelating reaction between molybdenum acetylacetone and glycerol as well as the Kirkendall effect induced by diammonium hydrogen phosphate. MoO2 nanoparticles coupled by amorphous carbon are assembled to unique zigzag-like hollow mesoporous nanosphere with large specific surface area of 147.7 m2 g−1 and main pore size of 8.7 nm. The content of carbon is 9.1%. As anode material for lithium-ion batteries, the composite shows high specific capacity and excellent cycling performance. At 0.2 A g−1, average discharge capacity stabilizes at 1092 mAh g−1. At 1 A g−1 after 700 cycles, the discharge capacity still reaches 512 mAh g−1. Impressively, the composite preserves intact after 700 cycles. Even at 5 A g−1, the discharge capacity can reach 321 mAh g−1, exhibiting superior rate capability. Various kinetics analyses demonstrate that in electrochemical reaction, the proportion of the surface capacitive effect is higher, and the composite has relatively high diffusion coefficient of Li ions and fast faradic reaction kinetics. Excellent lithium storge performance is attributed to the synergistic effect of zigzag-like hollow mesoporous nanosphere and amorphous carbon, which improves reaction kinetics, structure stability and electronic conductivity of MoO2. The present work provides a new useful structure design strategy for advanced energy storage application of MoO2.
EUROfusion-theory and advanced simulation coordination (E-TASC): programme and the role of high performance computing
Authors: Litaudon X , Jenko F , Borba D , Borodin D V , Braams B J , Brezinsek S , Calvo I , Coelho R , Donné A J H , Embréus O , Farina D , Görler T , Graves J P , Hatzky R , Hillesheim J , Imbeaux F , Kalupin D , Kamendje R , Kim H-T , Meyer H , Militello F , Nordlund K , Roach C , Robin F , Romanelli M , Schluck F , Serre E , Sonnendrücker E , Strand P , Tamain P , Tskhakaya D , Velasco J L , Villard L , Wiesen S , Wilson H , Zonca F
Published: December 2021

This paper is a written summary of an overview oral presentation given at the 1st Spanish Fusion High Performance Computer (HPC) Workshop that took place on the 27 November 2020 as an online event. Given that over the next few years ITER
24

24

ITER (‘The Way’ in Latin) is the world’s largest tokamak under construction in the south of France: a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy (https://www.iter.org/).

will move to its operation phase and the European-DEMO design will be significantly advanced, the EUROfusion consortium has initiated a coordination effort in theory and advanced simulation to address some of the challenges of the fusion research in Horizon EUROPE (2021–2027), i.e. the next EU Framework Programme for Research and Technological Development. This initiative has been called E-TASC, which stands for EUROfusion-Theory and Advanced Simulation Coordination. The general and guiding principles of E-TASC are summarized in this paper. In addition, an overview of the scientific results obtained in the pilot phase (2019–2020) of E-TASC are provided while highlighting the importance of the required progress in computational methods and HPC techniques. In the initial phase, five pilot theory and simulation tasks were initiated: towards a validated predictive capability of the low to high transition and pedestal physics; runaway electrons in tokamak disruptions in the presence of massive material injection; fast code for the calculation of neoclassical toroidal viscosity in stellarators and tokamaks; development of a neutral gas kinetics modular code; European edge and boundary code for reactor-relevant devices. In this paper, we report on recent progress made by each of these projects.
Spectral density of individual trajectories of an active Brownian particle
Authors: Squarcini Alessio , Solon Alexandre , Oshanin Gleb
Published: December 2021

We study analytically the single-trajectory spectral density (STSD) of an active Brownian motion (BM) as exhibited, for example, by the dynamics of a chemically-active Janus colloid. We evaluate the standardly-defined spectral density, i.e. the STSD averaged over a statistical ensemble of trajectories in the limit of an infinitely long observation time T, and also go beyond the standard analysis by considering the coefficient of variation γ of the distribution of the STSD. Moreover, we analyse the finite-T behaviour of the STSD and γ, determine the cross-correlations between spatial components of the STSD, and address the effects of translational diffusion on the functional forms of spectral densities. The exact expressions that we obtain unveil many distinctive features of active BM compared to its passive counterpart, which allow to distinguish between these two classes based solely on the spectral content of individual trajectories.
Band structures and topological properties of twisted bilayer MoTe2 and WSe2
Authors: Yu Guiqiang , Wen Lu , Luo Guoyu , Wang Yan
Published: December 2021

We calculate the electronic band structures and topological properties of twisted homobilayer transition metal dichalcogenides(t-TMDs), in particular, bilayer MoTe2 and WSe2 based on a low-energy effective continuum model. We systematically show how the twist angle, vertical electric field and pressure modify the band structures of t-TMDs, often accompanied by topological transitions.We find the variation of topological transitions mainly take place in a limited range of parameters. The electric field can efficiently tune the energy of the topmost second valence band to motify the Chern numbers of the topmost three valance bands. The topological property of the topmost first valance band can be modified by electric field and pressure, but doesn’t depend on twist angle. We show the band gap between the topmost second and third valance bands that both change from non-trivial to trivial closes at

κ

−

-point of the moiré Brillouin zone.
A first order dark SU(2)
D
phase transition with vector dark matter in the light of NANOGrav 12.5 yr data
Authors: Borah Debasish , Dasgupta Arnab , Kang Sin Kyu
Published: December 2021

We study a dark SU(2)
D
gauge extension of the standard model (SM) with the possibility of a strong first order phase transition (FOPT) taking place below the electroweak scale in the light of NANOGrav 12.5 yr data. As pointed out recently by the NANOGrav collaboration, gravitational waves (GW) from such a FOPT with appropriate strength and nucleation temperature can explain their 12.5 yr data. We impose a classical conformal invariance on the scalar potential of SU(2)
D
sector involving only a complex scalar doublet with negligible couplings with the SM Higgs. While a FOPT at sub-GeV temperatures can give rise to stochastic GW around nano-Hz frequencies being in agreement with NANOGrav findings, the SU(2)
D
vector bosons which acquire masses as a result of the FOPT in dark sector, can also serve as dark matter (DM) in the universe. The relic abundance of such vector DM can be generated in a non-thermal manner from the SM bath via scalar portal mixing. We also discuss future sensitivity of gravitational wave experiments to the model parameter space.
Spin of primordial black holes in the model with collapsing domain walls
Authors: Eroshenko Yu. N.
Published: December 2021

The angular momentum (spin) acquisition by a collapsing domain wall at the cosmological radiation-dominated stage is investigated. During the collapses, primordial black holes and their clusters can be born in various mass ranges. Spin accumulation occurs under the influence of tidal gravitational perturbations from the surrounding density inhomogeneities at the epoch when the domain wall crosses the cosmological horizon. It is shown that the dimensionless spin parameter can have the small values aS
 < 1 only for primordial black holes with masses M > 10-3M☉, whereas less massive black holes receive extreme spins aS
 ≃ 1. It is possible that primordial black holes obtain an additional spin due to the vector mode of perturbations.
Solving Surface Deformation of Radio Telescope Antenna by Artificial Neural Network
Authors: Wang Bo-Yang , Ye Qian , Fu Li , Meng Guo-Xiang , Wang Jin-Qing , Liu Qing-Hui , Shen Zhi-Qiang
Published: December 2021

Recent investigations have derived the relation between the near-field plane amplitude and the surface deformation of reflector antenna, namely deformation-amplitude equation (DAE), which could be used as a mathematical foundation of antenna surface measurement if an effective numerical algorithm is employed. Traditional algorithms are hard to work directly due to the complex mathematical model. This paper presents a local approximation algorithm based on artificial neural network to solve DAE. The length factor method is used to construct a trial solution for the deformation, which ensures the final solution always satisfies the boundary conditions. To improve the algorithm efficiency, Adam optimizer is employed to train the network parameters. Combining the application of the data normalization method proposed in this paper and a step-based learning rate, a further optimized loss function could be converged quickly. The algorithm proposed in this paper could effectively solve partial differential equations without boundary conditions such as DAE, which at the same time contains the first-order and the second-order partial derivatives, and constant terms. Simulation results show that compared with the original algorithm by Fast Fourier transform, this algorithm is more stable and accurate, which is significant for the antenna measurement method based on DAE.
Automation of data processing of the results of the chemical experiment on modeling the production of synthetic rubber using Microsoft Excel
Authors: Mikhailova Tatiana , Mustafina Sofia , Mikhailov Vladimir
Published: December 2021

The article presents an approach to the processing of chemical experiment’s data using a Microsoft Excel software. Instead of storing the experiment data in text files, it is proposed to use a Microsoft Excel file of a certain structure. A macro has been developed to automate the process of transferring data from text files to a common file. The described approach can be applied when solving problems accompanied by storing a large amount of statistical data, which can be obtained as a result of natural or computational experiments. The macro has been tested on the data of a laboratory and numerical experiment on the synthesis of a styrene-butadiene copolymer. This copolymer is formed as a result of carrying out the process of copolymerization in continuous mode in a cascade of continuous stirred tank reactors. The results of the experiment are the characteristics of the formed product for each reactor of the cascade at the end of each hour of process modeling. Transferring data into a single file of a certain structure allows you to graphically present the results of the experiment and facilitates further analysis of the characteristics of the product being studied, depending on the formulation and process conditions.
Comparative Study of Acoustic Parameter Reconstruction by using Optimal Control Method and Inverse Scattering Approach
Authors: Shishlenin Maxim A. , Izzatulah Mohammad , Novikov Nikita S.
Published: December 2021

Reconstruction of acoustic parameter such as acoustic velocity considers as part of inverse problems for mathematical physics and reasonable reconstruction of this parameter will assist solving interrelated problem such as inversion and imaging which are popular in the field of seismic imaging. In this work, we studied and conducted a comparative study between two methods; the optimal control method and inverse scattering approach. In optimal control method we are using conjugate gradient method for reconstructing the desired acoustic parameter while for inverse scattering approach, we are introducing the application of Marchenko integral equation. Furthermore, the numerical results for both approaches are presented for one dimensional problem along with the analysis from this comparative study.
The Stabilization of the Solution of an inverse Problem for the Pseudoparabolic Equation
Authors: Lyubanova A. Sh. , Velisevich A. V.
Published: December 2021

The asymptotic behavior of the strong solution to the inverse problem on recovering an unknown coefficientk(t) in a pseudoparabolic equation (u+ηMu)t+Mu+k(t)u=fis investigated. The differential operatorMof the second order with respect spacial variables is supposed to be elliptic and selfajoint. It is proved that the solution of the inverse problem stabilizes to the solution of the appropriate stationary inverse problem ast→ + ∞.
Artificial neural network for solving multi-parameter optimization problems
Authors: Olga Krivorotko , Shuang Liu
Published: December 2021

An artificial neural network (ANN) is a mathematical or computational model that simulates the structure and function of biological neural networks used to evaluate or approximate functions at given points. After developing the training algorithm, the resulting model will be used to solve image recognition problems, control problems, optimization, etc. In the process of ANN training, the algorithm of backpropagation is used in the case of convex optimization functions. The article is analyzed test functions for experiments and also study the effect of the number of ANN layers on the quality of approximation in cases one-, two- and three-dimensional. The backpropagation method is improved during the experiments with the help of adaptive gradient, as a result of which more accurate approximations of the functions are obtained. This article also presents the numerical results of test functions.
Approaches for investigation of oriented cracks of reservoirs using multicomponent VSP
Authors: Gorshkalev S B , Karsten W V , Vishnevsky D M , Yaskevich S V
Published: December 2021

The paper analyses the VSP data inversion in order to determine elastic constants of a transversely isotropic medium with a horizontal axis of symmetry of an infinite order (HTI), simulating an oriented fractured reservoir. Acquisition system of VSP is characterized by the absence of sub-horizontal directions of propagation of seismic waves. In this regard, it was necessary to determine the accuracy with which the elastic constants of the anisotropic layer are restored. The seismograms of the full wave field were selected as the initial data, calculated synthetically for the model of the medium containing azimuthally anisotropic layers. A complex of compressional and shear waves propagating from a source and recorded in the well. In such layers, the shear wave incident on the roof of the HTI layer splits into two waves that propagate at different velocities and have a mutually orthogonal displacement vectors. The processing task was to select waves S
1 and S
2 and build their arrival time curves. These arrival time curves were used in the inversion. The inversion was solved in the form of minimizing the functional of the mean square residual. Elastic constants, determined by inversion, almost exactly coincided with the model ones. The results obtained show the validity of the chosen approach for solving the inverse problem.
Modeling the integral risk assessment for air pollution in the areas of highways by probabilistic methods
Authors: Shagidullin A.R. , Tunakova Yu.A. , Novikova S.V. , Valiev V.S.
Published: December 2021

A methodology for calculating the integral risk of atmospheric pollution using Bayes’s theorem is proposed to take into account the action of mobile and stationary emission sources in the influence zones of highways, the response to the impact in the form of accumulation of emission components in depositing media and biological media of the population. At the first stage, the clustering of experimental data arrays was carried out, homogeneous road sections (clusters) were identified. The integral risk was calculated for the selected clusters. The risks of contamination of the investigated media have been calculated. A multiple regression model has been built to assess the level of integral risk with a high degree of reliability when compared with experimental data. The significance of the aerogenic factor in the formation of the level of integral risk is shown. A reduced model for assessing the integral risk by the level of risk of atmospheric air pollution is proposed. Grades of risk levels are given according to the degree of acceptability. It is possible to determine the contribution of the road transport component to the level of integral risk based on the obtained values of the final risk.
Using the automated Verasonics system for physical modeling of skeletal muscle biomechanics
Authors: Sinitsyn P M , Yu Demin I , Lisin A A , Spivak A E , Sinitsyna Yu V
Published: December 2021

The paper describes the use of the Verasonics research system for physical modeling of skeletal muscle biomechanics. The scheme of the acoustic system is described. The path of receiving and processing the signal is presented. A brief overview of the operation of software algorithms for the implementation of methods of ultrasound diagnostics is made. A mathematical model of skeletal muscle as a flat-layered medium is considered. The implementation of this model in the form of a fibers agar phantom is proposed. Using the Verasonics acoustic system shear velocities of physical fibers agar phantom were measured. Shear modules for agar and fibers were calculated. The obtained values are consistent with similar characteristics of native muscles and connective tissue fibers.
Tonality analysis in Wolfram Mathematica 12 computer algebra system
Authors: Gurin Anatoly A
Published: December 2021

Sentiment analysis is a class of methods that are used to automatically determine the tonality of statements in the text. There are many solutions and technologies to define of text tonality at the moment and the choice depends on task. With the release of Wolfram Mathematica 12 versions, it became possible to use included nlp methods for determination of text tonality. This article is about definition of text tonality in the wolfram Mathematica 12 using nlp and compare nlp methods with standard definition function.
A case study comparing static analysis tools for evaluating SwiftUI projects
Authors: Imbugwa Gerald Birgen , Araújo Luiz Jonatã Pires de , Khazeev Mansur , Enombe Ewane , Saliu Harrif , Mazzara Manuel
Published: December 2021

Declarative programming languages such as SwiftUI have gained increasing relevance for user interface implementation in mobile applications. A tool for evaluating and improving the quality of such projects is static analysis (SA). This study compares the usefulness of two of the most popular SA tools (SonarQube and Codacy) for evaluating real-world SwiftUI projects. Moreover, it recommends setup and adjustments to promote SA tools for SwiftUI projects that can be extended to other languages.
Evaluation of cell load of the LTE network based on control information decoding
Authors: Galimullin Bulat , Chirkov Daniil , Gaysin Artur , Ashaev Ivan
Published: December 2021

Cell load evaluation is the one of the tools used for the development of methods to increase quality of service (QoS) in cellular networks. For instance, the analysis of mobile traffic usage can be used for network optimization and management in terms of radio resources. Existing assessing methods, such as drive tests or passive evaluations based on analysis of physical channel indicators are either unreliable, inaccurate, or inconvenient. A cell load evaluation method based on decoding and analysing the control channels is presented. The method can reliably monitor the resource allocations and the throughput in a public mobile cell. A real LTE signal recorded from the eNodeB using software defined radio was analysed. The main indicators of the cell were determined, including the efficiency of using resource blocks, the number of active users, and the cell’s throughput. The accuracy of the algorithm was also evaluated in this paper.
SCMA-MIMO system with adaptation to the channel state
Authors: Pokamestov Dmitriy , Kryukov Yakov , Rogozhnikov Eugeniy , Kanatbekuli Islam , Dmitriyev Edgar
Published: December 2021

Sparse code multiple access (SCMA) is one of the promising implementations of non-orthogonal multiple access (NOMA) methods. SCMA provides high spectral efficiency and a large number of network resources. We describe a communication system with SCMA, space-time block coding (STBC), multiple input multiple output (MIMO) technology, and orthogonal frequency division multiplexing (OFDM). The architecture of such systems, including algorithms of formation and processing of signals is considered. A method for adapting signals to the state of the spatial channel transmission based on information about the matrix of channel coefficients is proposed. The application of such adaptation allows to compensate the influence of the channel and to reduce the probability of bit errors. We consider the bit error rate (BER) performance of the communication system in different channel models and show the effectiveness of the proposed methods.
Probabilistic model for the analysis of elastic session duration in wireless networks
Authors: Sopin Eduard , Daraseliya Anastasia , Shorgin Sergey
Published: December 2021

In wireless networks, the bitrate received by a user session depends not only on the fraction of allocated resources of the base station but also on the number of factors affecting the signal-to-noise ratio. These factors include a distance between a mobile device and the base station, walls, buildings between them, etc. As a result, the bitrate of elastic sessions may differ tenfold. In this paper, we develop a probabilistic model that captures the main specifics of the data transmission through a wireless network by introducing the random serving rate coefficients concept. With the help of the model, we derived the cumulative distribution function of the elastic session duration.
Study of charge carrier transport properties and lifetimes in HR GaAs:Cr with Timepix3
Authors: Smolyanskiy P. , Bergmann B. , Billoud T. , Burian P. , Sitarz M. , Søndergaard C. , Pospíšil S.
Published: December 2021

The response of a Timepix3 (256 × 256 pixels, pixel pitch 55 μm) detector with a 500 μm thick HR GaAs:Cr sensor was studied in proton beams of 125 MeV at the Danish Centre for Particle Therapy in Aarhus, Denmark and in a 120 GeV/c pion beam at the Super-Proton Synchrotron (SPS) at CERN. The sensor was biased at different voltages and irradiated at different angles. The readout chip was configured to operate in electron and hole collection modes. Measurements at grazing angles allowed to see elongated tracks with well-defined impact and exit points, so that charge carrier production depths could be determined in each pixel. We extracted the charge collection efficiencies and the charge carrier drift times as a function of the distance to the pixel plane. It was found that measured proton tracks are shorter in hole collection than in the case of electron collection, which is explained by the shorter lifetime of holes. At an angle of 60 degrees with respect to the sensor normal, the average track length in hole collection was ∼700 μm and 950 μm in electron collection mode. To understand the experimental findings, models describing the properties of HR GaAs:Cr were implemented into the Allpix2 simulation framework. We added previously presented experimental results describing the dependence of the electron drift velocity on the electric field and validated the response by comparing measurement and simulation for various X- and gamma-ray sources in the energy range of 10–60 keV. By comparison of the experimental and the simulated results, the mobility μ
h and the lifetime of holes τ
h were estimated as μ
h = (320 ± 10) cm2/V/s and τ
h = (4.5 ± 0.5) ns.
Generalising the Horodecki criterion to nonprojective qubit observables
Authors: Hall Michael J W , Cheng Shuming
Published: December 2021

The Horodecki criterion provides a necessary and sufficient condition for a two-qubit state to be able to manifest Bell nonlocality via violation of the Clauser–Horne–Shimony–Holt (CHSH) inequality. It requires, however, the assumption that suitable projective measurements can be made on each qubit, and is not sufficient for scenarios in which noisy or weak measurements are either desirable or unavoidable. By characterising two-valued qubit observables in terms of strength, bias, and directional parameters, we address such scenarios by providing necessary and sufficient conditions for arbitrary qubit measurements having fixed strengths and relative angles for each observer. In particular, we find the achievable maximal values of the CHSH parameter for unbiased measurements on arbitrary states, and, alternatively, for arbitrary measurements on states with maximally-mixed marginals, and determine the optimal angles in some cases. We also show that for certain ranges of measurement strengths it is only possible to violate the CHSH inequality via biased measurements. Finally, we use the CHSH inequality to obtain a simple necessary condition for the compatibility of two qubit observables.
Precipitation Water Vapour Variation in the East Java Region from Data CORS Using GIPSY
Authors: Handoko Eko Yuli , Kurniawan Akbar , Maulida Putra , Cemara Norma Aji
Published: December 2021

The Global Navigation Satellite System is being developed as an atmospheric remote sensing system through the calculation of Zenith Total Delay. The development of the Continous Operating Reference Station encourages research investigations into Zenith Tropospheric Delay with continuous data and good spatial resolution. This research studies the characteristics of spatial and temporal variations of the Zenith Wet Delay in East Jawa. The case study in East Jawa Province uses 16 Continous Operating Reference Stations. As a comparison, meteorological data from the Badan Meteorologi, Klimatologi, and Geofisika stations are used.The Zenith Total Delay and Zenith Wet Delay values from the Continous Operating Reference Station data are calculated using GIPSY 6.4 Software. The Zenith Wet Delay values are gridded using the kriging method with the size of the grids being 0,25 x 0,25. The ZWD value comparison from the Continous Operating Reference Station and meteorology data has a strong correlation with a coefficient value of 0,712. The mean of Zenith Wet Delay’s trend is increasing by about 0,712 mm/yr. The characteristics of the spatial and temporal variations of the ZWD value are influenced by the monsoon of Asia-Australian, which causes dry and rainy seasons, global phenomena such as El Nino and La Nina, rainfall, local meteorological conditions such as temperature and humidity, weather, and the topography of the stations.
Determination of the relevant multibeam echosounder frequency to estimate the suspended sediment concentrations for environmental damage monitoring of mass movement
Authors: Hariyanto I H , Pratomo D G , Maulana M A
Published: December 2021

The problem of environmental damages in the river area can transform the morphology and threaten the ecosystem in it with one of the causes being natural factors such as suspended sediment. Retracing the medium form is fluid, the common instrument to determine the condition of the area is a sound wave-based instrument such as a multibeam echosounder. Considering the improvement of multibeam echosounder which can acquire areas using many frequencies at one time, noted as multi-frequency multibeam echosounder, now its application can reach various fields including environmental monitoring. Factors that can be considered in its practice include time efficiency, cost, and notably the accuracy of the data result. By converting the results of the acquisition into an estimate of the concentration of suspended sediment and integrating the results from several frequencies, it will be established the applicable frequency usage. It was concluded that a multibeam echosounder with a frequency of 450 kHz was recommended in a case study to determine the concentration of suspended sediment. This is supported by a correlation value of 89.18% or a very high correlation.
The Suitability Analysis of Land Use and Building from BIM to Spatial Detail Plan
Authors: Sukojo Bangun Muljo , Rahmani Kania Hana
Published: December 2021

The development in urban areas will continue to occur, such as the construction of settlements, offices, shops, educational and health facilities, and other supporting facilities. With the development that will always continue to occur in a nation, it will also increase the productivity in its city. The rapid development of urban activities will also followed by high demand for land. This can lead to land conversion. Therefore, it is necessary to use the land to its optimal capacity and manage it wisely in order to produce a quality space that is maintained for its sustainability. Rules and regulations are compiled into a plan in the Guidelines for the Preparation of Detailed Spatial Planning (RDTR). This research conducted in North Gandaria Urban Village because the buildings are divided into three environments, namely densely populated settlements, middle to upper settlements, offices and shops which based on geometrical aspects have various building forms from small to large ratios. Each building has different diverse land and building usages. In this study, land use suitability was identified by manual and digital classification, namely by image interpretation and classifying using the Object Based Image Analysis (OBIA) method on SPOT-7 images which were then superimposed to produce land use maps. In addition, this study utilizes altitude data from LiDAR to complement building spatial data and is processed to BIM. BIM dimensions are made in 3D with Level of Development 100 or equivalent to Level of Details 1 which has a flat roof if converted. From this research resulted suitability of land use and buildings to carry out an analysis related to sustainability and can be used as consideration and input by the policy makers on spatial planning policies. Based on the results of the analysis, it was found that the suitability of land use was 95% classified suitable to spatial detail plan. To determine the suitability of the building in this study, it was seen from the activities of the building and the height of the building. Based on building activities, 9.30% of building activities that are not allowed and another 90.70% are classified as conditionally allowed buildings, allowed, limited alowed and limited and conditional. Meanwhile, based on the height of the building, there are 82.7% of buildings that comply with the spatial detail plan.