bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of a Family of Dynamic Systems with Reciprocal Polynomial Right Parts in a Poincare Circle
Authors: Andreeva I A 
Published: December 2019

Abstract
A paper describes methods and results of a fundamental study of some family of dynamic systems having reciprocal polynomial right parts, which is considered on the arithmetical (real) plane. One of the equations in these systems includes a cubic form in its right part, while the other one includes a square form. The goal was to find out all topologically different phase portraits possible for differential dynamic systems under consideration in a Poincare circle and outline close to coefficient criteria of them. A Poincare method of consecutive central and orthogonal mappings has been applied, and allowed to obtain more than 230 independent phase portraits. Each phase portrait has been described with a special table, every line of which corresponds to one invariant cell of the portrait and describes its boundary, as well as a source and a sink of its phase flow.
All finite and infinitely remote singularities of considered dynamic systems were investigated.
Dendrochronology Regression Models in Aufeis Formation Analysis
Authors: Pomortseva A A , Pomortsev O A , Rozhin S S , Trofimtsev Yu I 
Published: December 2019

Abstract
The paper examines the historical behaviour of such unique natural phenomena as the sheets of aufeis in the North East of Russia. They are studied using statistical methods for analyzing dendrochronological data. Dendrochronology is a scientific method based on comparing quantitative indicators of tree ring growth and the dynamics of aufeis formation in the past. Tree ring growth is an integral indicator which reflects the diversity of conditions in which trees grow and interact with the environment. Time series were obtained for the Ulakhan-Taryn and Buluus aufeis deposits located in the Middle Lena basin in Central Yakutia. Regression models were created using dendrochronological data, with the majority of the models being nonlinear. The sample mean, sample variance, and sample correlation coefficient were calculated for the time series. The regression model of the time series under study was represented as a combination of a non-random component, including the age trend and a climatic component, and a random component with zero expectation, which is the sum of factors unaccounted for, including autocorrelation. Depending on the locations where data were collected, both strong and moderate and weak dependencies of pine growth on aufeis influence were revealed. If there was strong or moderate aufeis influence, humidity had a minor impact on tree growth. If aufeis influence was weak, tree growth was moderately influenced by precipitation. There is a moderate dependence of tree growth on air temperature in all cases.
Graph topology resulting from addition and deletion of nodes determined by random walk
Authors: Ikeda Nobutoshi 
Published: December 2019

Abstract
How the power-law form of the degree distribution of networks can survive in the equilibrium state of number of nodes is an open question, since the deletion of nodes seriously affects the degree distribution. In this paper, we introduce a network evolution rule based on a random walk to describe the replacement of nodes in networks. Numerical results show that model assumptions support the power-law form of degree distribution even when the replacement of vertices achieves an equilibrium state of the number of vertices, and the distribution is described by the distribution of the maximum degree that each node experiences in its life. We showed additionally that the reduction of the addition probability of nodes causes an edge condensation to hub nodes. A novel feature of the model is that the visit frequency and recurrence property of the walker to a vertex determines the degree and lifetime of the vertex in an equilibrium state of the number of vertices.
Structural properties of two-phase deterministic multifractals
Authors: Marcelli Giorgia 
Published: December 2019

Abstract
In this work an analysis of the multifractal spectra, pair distance distribution function (pddf) and small-angle scattering (SAS) intensities from deterministic two-scale multifractals is performed in order to determine their structural properties. It is shown that the coefficients of the pddf are characterized by the presence of groups of distance pairs whose positions are related to the scaling factors of the fractal. It is found that the box counting dimension D
0 in the multifractal spectra coincides with the mas fractal dimension determined through the evaluation of scattering exponent in the fractal region of SAS curve. The length of the mass fractal region in reciprocal space is related to the relative values of the scaling factors. We illustrate these findings on a 2D Vicsek-like multifractals.
Fuzzy dynamic models of situation analysis, decision support, and control in complex systems
Authors: Bagdasaryan Armen , Gavric Dubravka 
Published: December 2019

Abstract
In this work we consider the theoretical foundations of building fuzzy models of system dynamics, analysis of situations, their development, and control in complex weakly-structured systems based on knowledge modeling and expert preferences. The proposed fuzzy models can serve as mathematical tool for analyzing the behavior of a system in various situations, as well as to serve as the basis of specialized computer simulation systems of decision support in unstructured fuzzy situations. As is known, decision making problems under uncertainty can be divided into two groups: decision making in static situations and decision making in dynamic situations. For decision making in static situations, the methods and models of decision support based on the theory of choice are developed. For decision-making in dynamic situations, the dynamic models, including those based on expert knowledge, are used. To build a dynamic model of a situation, the expert knowledge about physical, economic, or social processes occurring in a system, which are represented as a cognitive map, is employed. The models of analysis of static situations are focused on evaluation and ordering of alternatives, and models of analysis of dynamic situations are focused on generating of strategies (alternatives) to achieve the targets of control, that is, the desired target state of the situation. Thus, one of the aims of this paper is to develop mathematical methods for constructing integrated decision support models based on fuzzy models of hierarchical estimation, control, and fuzzy cognitive modeling.
Analysis of the probability distribution of time series of word frequencies
Authors: Bochkarev Vladimir V. , Shevlyakova Anna V. 
Published: December 2019

AbstractKnowledge of probability distribution of frequency of words and phrases is important in solving many practical problems such as estimation of semantic similarity between words, detection of semantic changes and others. It is assumed by many researchers that frequencies of words obey the Poisson law. However, there is much evidence that the Poisson distribution describes empirical data unsatisfactory. The analysis of the probability law in this case is greatly complicated by the fact that series of frequencies in most cases are non-stationary. This paper discusses the distribution law of time series of word frequencies based on the Google Books Ngram corpus data. It is shown that the correlation between the first moments of the frequencies differs from that expected in the assumption of the Poisson distribution. In particular, anomalously high values of frequency dispersion are observed for words with high frequency. To check the significance of deviations from the Poisson law, statistical modeling of frequency series was performed.
A two-stage opinion formation model based on the extended XY-magnet interaction and socio-dynamic update mechanism
Authors: Prenga D. 
Published: December 2019

Abstract
We introduce herein a two stage model of opinion formation in a community of individuals which share strong interests within a permanent pair, and attend also a persuasion social process with others to finalize their attitudes. In the first step, individuals behave as member of their couples and seek to optimize respective satisfaction. Then, they modify their attitudes inherited from the first stage throughout a persuasion process and social influence. The first stage consists in an extension of a classical XY magnet model, and the calculation in this step are performed using statistical mechanics tools. At the end of this phase, each opinion agent has adapted its support Ox for the issue F and the agreement within their pair O = |
O
1 + O
2
|. The evaluated quantities Ox
(i) depend on the magnetic-like system parameters J, T, F and on the extra parameter α(i) which embodies the dissimilarity of the system utility from the reference Hamiltonian. The set {Ox
(i), O(i)} represents the opinion state of the community straightaway after the first stage, and is presented hereto with respective histogram. We observed that histograms of Ox
(i) approximate to q-Gaussian distributions for moderate F/T ratio, and approaches to power law distributions for low F/T ratio. The histograms of the inner agreement O(i) do not fit well to a given distribution, and therefore, the social comportment which we identify hereto with this set, is not a stationary quantity under this approach. Next, the opinion quantities Ox
(i) will pursue an update course as result of the persuasion process and social influence. We performed the calculation based on Deffuant and Heglesman models by using Ox
(α
i
)
F,J,T
as initial opinion values. We observed that the final opinion fragmentation resulted lower than when using standard assumptions of those models and also, the time to consensus was shorter. Next, for the special case where there are only two output final opinion values, the lower one needs more iteration time steps to converge. In our approach, usually the lowest level opinion converge slower than higher ones. Finally, we have implemented a modified preferential attachment model to realize a network of the linked nodes based on the opinions Ox
inherited from the early stage. We acknowledged the power law distribution of the grades of nodes, but in our case there are no disturbances in the queue of the histogram, which are common in the standard simulation for such networking process. As conclusion, having regard to every aspect and specifics, we believe that the proposed model would help on the understanding of the complexity of social conduct.
The Solution Cosmological Constant Problem. Quantum Field Theory in Fractal Space-Time with Negative Hausdorff-Colombeau Dimensions and Dark Matter Nature
Authors: Foukzon Jaykov , Men’kova Elena R , Potapov Alexander A 
Published: December 2019

Abstract
The cosmological constant problem arises because the magnitude of vacuum energy density predicted by quantum field theory is about 120 orders of magnitude larger than the value implied by cosmological observations of accelerating cosmic expansion. We pointed out that the fractal nature of the quantum space-time with negative Hausdorff- Colombeau dimensions can resolve this tension. The canonical Quantum Field Theory is widely believed to break down at some fundamental high-energy cutoff Λ* and therefore the quantum fluctuations in the vacuum can be treated classically seriously only up to this high-energy cutoff. In this paper we argue that Quantum Field Theory in fractal space-time with negative Hausdorff-Colombeau dimensions gives high-energy cutoff on natural way. We argue that there exists hidden physical mechanism which cancel divergences in canonical QED
4, QCD
4, Higher-Derivative - Quantum-Gravity, etc. In fact we argue that corresponding supermassive Pauli-Villars ghost fields really exists. It means that there exists the ghost-driven acceleration of the univers hidden in cosmological constant. In order to obtain desired physical result we apply the canonical Pauli-Villars regularization up to Λ*. This would fit in the observed value of the dark energy needed to explain the accelerated expansion of the universe if we choose highly symmetric masses distribution between standard matter and ghost matter below that scale Λ*,i.e., fs.m
(µ) ≈ −fg.m
(µ), µ = mc, µ ⩽ µ
eff, µ
eff < Λ*/c. The small value of the cosmological constant explaned by tiny violation of the symmetry between standard matter and ghost matter. Dark matter nature also explaned using a common origin of the dark energy and dark matter phenomena.
Robust stability of a class of differential systems with state after-effect dynamics
Authors: De la Sen M. 
Published: December 2019

Abstract
This paper is concerned with the investigation of the global stability and global asymptotic stability of the error with respect to its nominal version of a non-linear time-varying perturbed functional differential system which is influenced by point, finite-distributed and Volterra-type distributed delayed dynamics. The boundedness of the error and its asymptotic convergence to the zero equilibrium are investigated and some formal “ ad- hoc” results are proved.
Modeling of the process of treatment of polluted washing water in circulating water systems
Authors: Melekhin AA 
Published: December 2019

Abstract
Optimization of the process of treatment of circulating water is an important scientific and technical task. Consideration of this issue is proposed on the example of cleaning washing water. The creation of water use systems at industrial enterprises in the recycling cycle is associated with the need for a new approach to the formulation of research, design and operation of water recycling systems. The modeling of the process of cleaning polluted washing water in circulating water use systems and solutions to the problems of optimizing the process parameters. We have elaborated a mathematical model of management of circulating water system. Thus, application of the offered technique allows to solve a problem of optimization of process of purification of the polluted waters for circulating systems of water consumption. On the basis of this technique the technological scheme of cleaning of the polluted washing waters is developed is based on application of a combination of ways of destruction of structure of pollution and ways of separation of the destabilized pollution. The technological scheme of cleaning contaminated washing water is based on a modular method of constructing a cleaning device, which is based not on individual ingredients or their dispersion, but on the type of contaminants present: pop-up, sedimentary, suspended-emulsified contaminants.
A multi-temperature kinetic Ising model and its applications to partisanship dynamics in the US Senate
Authors: Mazilu I. , Lorson A. P. , Gibbs S. , Hanstedt W. , Mazilu D. A. 
Published: December 2019

Abstract
As the political landscape becomes increasingly complex, the classic paradigms used in political science have failed to remain relevant and other methods of study are needed. We introduce a population dynamics model and a multi-temperature kinetic Ising model to analyze the partisanship dynamics of the US Senate. We use Monte Carlo simulations, mean field theory and numerical analysis of the master equation of a system of 100 senators (agents) separated into various categories based on their political leanings and interactions with each other. Results show an interesting development of partisanship between the agents after a short time. The model can be extended to other cooperative stochastic systems in physics and social sciences.
Pressure - velocity projection method with mixed type approximation for Oseen discrete operator
Authors: Evstigneev Nikolay M. , Ryabkov Oleg I. 
Published: December 2019

Abstract
We are considering the problem of divergence - free projection in rectangular domains for the Oseen (stationary Navier-Stokes) operator. It uses nodal Finite Element method to reconstruct pressure and Finite Difference method for scalar functions and vector functions for other parts of the equations. This allows us to use simple finite difference schemes for linear part and WENO-type schemes for the the nonlinear part in the space of discrete velocities. The boundary conditions are formulated in Finite Volume conservative approach for velocity and in Finite Element approach for pressure. We illustrate that the convergence rate depends on the smoothness of the projected function and that the projection method allows one to obtain divergence-free solutions with desired tolerance. We numerically analize the projection operator that acts in the space of divergence operator image. It is shown that all eigenvalues of the operator are less than unity for Oseledets-type wall boundary conditions for velocity and zero Neumann conditions for the Poisson equation. We show that for smooth functions we obtain forth order convergence in divergence. Finally we demonstrate the method by solving the stationary lid driven cavity problem for the 2D Oseen operator.
Numerical model of evaporation of tungsten in vacuum under high-power transient heating
Authors: Lazareva G G , Arakcheev A S , Maksimova A G , Popov V A 
Published: December 2019

Abstract
On the BETA facility, an electron beam is used for simulation of pulsed thermal loads on ITER-relevant tungsten. Numerical experiments are used for verification of the models. This paper presents extension of the model of electron beam heating, supplemented with dynamics of gas evaporation from a heated surface in vacuum.
Logistic map as a Fourier’s series expansion: numerical analysis
Authors: Lawnik Marcin 
Published: December 2019

Abstract
Logistic map is one of the simplest, and at the same time the most commonly used dynamic system, which is characterized by chaos. The article presents approximations of the logistic map through its extension into the Fourier’s series. Obtained in such way dynamical systems were analyzed, among others for the Lyapunov exponent and bifurcation diagrams. Furthermore the issue of the density of the iterated variable and some applications in chaos based cryptography were commented.
Structure and properties of atomic nuclei in the theory of compressible oscillating ether
Authors: Magnitskii Nikolai 
Published: December 2019

Abstract
In the work, based on the equations of the compressible oscillating ether, derived from the laws of classical mechanics, ether mathematical models of the nuclei of atoms of chemical elements are constructed. It is shown that the nucleus of any atom is a superposition of perturbation waves of ether density in several protons and several neutrons, having a common center and propagating around a common axis in one direction or in opposite directions, that is, having unidirectional or oppositely directed spins. Formulas for the values of internal energies, masses, magnetic moments, and binding energies of atomic nuclei are derived, with an accuracy of fractions of a percent coinciding with their experimental values. Formulas for calculating the radii of atomic nuclei are obtained. Answers are given to many topical questions about the structure of atomic nuclei that modern atomic physics is not capable of answering, for example: why there are no nuclei consisting only of protons or only of neutrons; what is the nature of the nuclear forces holding together protons and neutrons in the nucleus; why the sizes of atomic nuclei practically do not depend on the atomic number of the chemical element; why the Coulomb barrier of the nucleus selectively works; why the fragments of the decomposition of heavy elements into two nuclides are asymmetric; what is the reason for the different percentage in nature of different isotopes of the same chemical element?
Design of narrowband multiplierless comb compensator with low passband deviation
Authors: Dolecek Gordana Jovanovic 
Published: December 2019

Abstract
The simplest decimation filter is a comb filter which has all coefficients equal to unity, and consequently does not require multipliers for its implementation. However, comb filter does not have the flat passband characteristic, which is increases with the increase of the number of cascaded comb filters. The passband droop must be compensated by a filter called comb compensator. In this paper we present novel narrowband multiplierless compensator which results in a low absolute value of the passband deviation of the compensated comb, which is less than 0.01dB. The compensator has a magnitude response synthesized as sine wave functions. The parameters of design are the amplitudes of sine wave functions, which depend on the order of the comb filter and practically do not depend on the decimation factors. The designs for two values of the passband edge frequencies are elaborated and illustrated with examples.
Magnetorheological gel-based magnetoresistor: Effects of a static and a periodic time-varying magnetic field on the electrical resistance
Authors: Bica I , Cîrţînă L , Cîrţînă D , Chirigiu L , Chirigiu L M E 
Published: December 2019

AbstractA magnetoresistor having as resistive element a magnetorheological gel (MG) based on silicone rubber and Fe microparticles is fabricated. An experimental setup is built and described for measuring the electrical resistanceRof the magnetoresistor in a static and in a periodic time-varying magnetic field (PTVMF). The results show that the resistance is significantly influenced by increasing the magnetic flux density, and the PTVMF induces transient processes inside the magnetoresistor. We explain these processes.
Application of the artificial neural network in the forecasting of the airborne contaminant
Authors: Wawrzynczak A , Berendt-Marchel M. 
Published: December 2019

Abstract
Release of hazardous materials in chemical industries is a significant threat to surrounding areas. This thread can be answered by the reconstruction system capable of localizing the source of airborne contamination solely based on substance concentrations recorded by the sensors network. However, such systems require multiple runs of the selected atmospheric contaminant transport model. The complexity of the contaminated terrain involves the application of the complicated and computationally expensive dispersion models, while the fast one is too simplified. We examine the possibility of training an artificial neural network (ANN) so that it could effectively simulate the atmospheric toxin transport. The use of a fast neural network in place of costly computational dispersion models in systems localizing the source of contamination might significantly improve their efficiency (speed). In this paper, we train the ANN with the use of the training dataset covering the contamination source term parameters and point output concentrations generated by the Gaussian dispersion model. We test various ANN structures, i.e., numbers of ANN layers, neurons, and activation functions to achieve the ANN capable of estimating the contaminant concentration. Applying the specified ANN topology we train ANN with use of the real field Prairie Grass experiment data. The performed tests confirm that trained ANN has the potential to replace the dispersion model in the contaminant source localization systems.
Numerical solution of flow in bypass for generalized Newtonian fluids
Authors: Keslerová Radka , Řezníček Hynek , Padělek Tomáš 
Published: December 2019

Abstract
This work presents the numerical solution of generalized Newtonian fluids in the bypass geometry. The considered geometry consists of the narrowed host tube and the bypass graft with 30, 45, 60 degrees angle of the connection. Two values of the Reynolds number, 100, 200, are tested. The numerical results of non-Newtonian fluids are compared to the results of Newtonian fluids. The governing system of equations is based on the system of balance laws for mass and momentum. Generalized Newtonian fluids flow in the bypass tube is numerically simulated by using SIMPLE algorithm included in OpenFOAM.