bluuebunny/crossref_metadata_2025_split huggingface dataset:
The condition number of a matrix as an optimality criterion in the problems of parametric identification of linear equations systems
Authors: Kantor O G , Spivak S I , Petrenko V R 
Published: May 2020

Abstract
When solving applied problems, an important aspect of the analysis is the stability of the obtained solution with respect to experimental data errors. Empirical experimental data, although a priori inaccurate, can be represented by intervals of their range of values. In some cases, the limits of their variation may also be known. Obviously, the degree of inaccuracy of input data influences the solution of the parametric identification problem. Therefore, in the case when this solution is not the only one, methods for assessing the influence of experimental error on the stability of each potential solution are of interest as they may provide additional arguments in favour of choosing one of them. In the case of models formalized in the form of systems of linear algebraic equations, a similar effect can be investigated using the condition number. In a case of quantitative analysis of multicomponent mixtures, the paper presents an approach to the parametric identification of linear models based on the calculation of the maximum permissible parameter estimates in combination with the study of the coefficient stability of the system.
Method of forming expert coalitions in the context of solving the expertise problem of alternatives with weakly formalized criteria
Authors: Melnikov A V , Shcherbakova I V , Zhilin R A 
Published: May 2020

Abstract
The article describes the worked on numerical technique for forming alternative coalitions of experts relating to solving weakly formalized problems and the results of verification of the proposed method by the example of the studying the attributes of violators in the field of physical protection of critical information infrastructure objects. The proposed methodology for conducting preliminary examination on the basis of the worked on numerical method for identifying coalitions of experts allows to perform the procedure for forming an agreed group of experts and obtaining preliminary estimates of the significance of the attributes of a violator during a single survey of experts, that significantly saves time and reduces the complexity of the expertise of objects. Using the worked on numerical method, the main and two alternative coalitions were identified. Taking into account the alternative opinion of experts allowed 31 experts to be identified as agreed upon, which more precisely determines the results of the expertise.
Simulation of wave impact on shore protection structures using 3D model of wave processes
Authors: Protsenko S V 
Published: May 2020

Abstract
The article is devoted to the research of the effects of wave processes on shore protection structures using mathematical model of wave processes based on the system of Navier-Stokes equations, which includes three equations of motion in areas with dynamically changing geometry of the computational domain. The pressure correction method is used for the approximation of a hydrodynamic model. The difference schemes describing the mathematical model of the wave propagation towards the shore are constructed on the basis of the integro-interpolation method using the scheme with weights. An adaptive alternating-triangular iterative method is used to solve the system of grid equations. The model presented in the article gives more realistic description of the physical wave process near the coastline. The practical significance of the numerical algorithms and program complex for their implementation is the possibility of their application in the study of hydrophysical processes in the coastal water systems, as well as to build the velocity and pressure fields of the water environment and the evaluation of hydrodynamic effects on shore protection structures and coastal structures.
On using artificial neural networks for calibrating tempered stable Lévy processes to probabilities of crossing absorbing barriers
Authors: Kudryavtsev O , Rodochenko V 
Published: May 2020

Abstract
We propose a new method for calibrating tempered stable Lévy processes based on an artificial neural network (ANN), which takes probabilities of crossing a number of fixed barriers by a random walk as input data, and demonstrate its performance for the widely used CGMY model. To train the network we use real historical data and a synthetic dataset. We download and prepare the former to create a sequence of histograms with historical probabilities of crossing the set of barriers by log-returns of the underlying asset. To construct the synthetic dataset, we generate the values of the CGMY model’s parameters and calculate the respective probabilities of crossing the barriers as prices of synthetic one-touch-digital options by means of an effective numerical method, which is based on the fast Wiener-Hopf factorization technique. After that, we become able to calibrate the parameters for this model by means of the trained ANN, using the probabilities as input data. As the result, we obtain a fast method to calibrate the CGMY Lévy model, which can be used to solve risk management problems on financial markets – especially for the case where the asset under consideration is highly liquid and highly volatile at the same time (e.g. cryptocurrencies).
An analysis of the models informativeness in parametric identification problems
Authors: Kantor O G , Spivak S I , Podvalny S L 
Published: May 2020

Abstract
Solving problems of parametric identification with uncertainty in the initial data due to their inaccuracy and incompleteness complicates, and, in some cases, even rules out the possibility of using classic mathematical and statistical methods as the latter are meant to deal with sufficiently large amounts of observations. These conditions involve the use of specific methods to directly determine the exact type of functional link and to verify its qualitative characteristics. A set of such characteristics also forms an idea of the informativeness of a model. This paper considers the characterization of this concept in relation to parametric identification problems and presents a method of their solution where the procedure of the analysis of informativeness of the obtained models is formalized. Approbation of the developed technique was carried out on the example of parametric identification of the time series model. This time series cannot be linearized. A small number of observations were also known. All these conditions precluded the use of statistical methods to construct a time series model.
Method of paralleling grid nodes for multidimensional regions when solving parametric identification tasks
Authors: Kantor O G , Spivak S I , Yusupova G N , Podvalny E S 
Published: May 2020

Abstract
One of the approaches to solving parametric identification problems is based on numerical methods. In fact, their use is reduced to the process of iterating over the elements of multidimensional areas of the desired parameters. Increasing the density of the introduced grid increases the amount of calculations and time spent on the process of their implementation. Increasing the density of the introduced grid increases the amount of calculations and time spent on the process of their implementation. In this regard, it is desirable to improve the efficiency of the computer systems used. An important direction in the context of the above is the development of procedures for parallelization of programs. The article presents an algorithm for searching the nodal points of multidimensional areas based on the principle of data decomposition. In regard to solving the problem of parametric identification of the diffuse Bass model of the spread of innovation, its practical implementation has been carried out.
Investigation of interaction of borocarbon nanotubes with gas phase atoms
Authors: Boroznin Sergey , Zaporotskova Irina , Boroznina Natalia , Bakhracheva Yulia 
Published: May 2020

Abstract
During the study of adsorption interaction by computer modeling, it was found that adsorption of oxygen, fluorine and chlorine atoms is possible on the surface of a carbon nanotube. In the course of comparing the surface sorption activity of BC5 nanotubes with respect to various chemical elements, it was found that the interaction of the oxygen atom with the surface of the borocarbon nanotube is the most energetically advantageous. The introduction of boron atoms promotes a more active addition of oxygen, fluorine and chlorine atoms to the surface of the nanotube, that is, structural modification leads to an increase in the sorption activity of carbon nanotubes.
Simulation of the coordination number of random sphere packing
Authors: Migal L V , Bondarev V G , Chekanov N A , Bondareva T P 
Published: May 2020

Abstract
Given article presents a generalized equation for calculating the average coordination number from the density of a random sphere packing, supplemented by a dependence on the threshold value of the interparticle distance in two- and three-dimensional spaces. It is shown that the calculation of the average coordination numbers according to the proposed equation gives an unambiguous correspondence between the simulated, calculated and experimental data for threshold values of more than 1.02 particle diameters. An explanation of the weak dependence of the average coordinate number on the packing density for small threshold values of the interparticle distance is given in this work.
Search for the optimal temperature regime for the synthesis of benzylidenebenzylamine based on genetic algorithms
Authors: Antipina E V , Mustafina S A , Antipin A F , Podval’nyi E S 
Published: May 2020

Abstract
The article is devoted to the creation of an algorithm for finding the optimal temperature regime of a chemical reaction based on evolutionary calculations. The problem of optimal control for a chemical process is formulated in a general way. A genetic algorithm for solving the problem is described. A computational experiment was carried out for the synthesis reaction of benzylidenebenzylamine in order to obtain the maximum yield of the product during the reaction. The optimum temperature profile and the optimal concentration of reagents were obtained. Based on the formulated genetic algorithm, a program was developed in the visual programming environment Delphi, which allows finding the optimal temperature profile of the chemical process.
Probability distributions unimodality of finite sample extremes of independent Erlang random variables
Authors: Virchenko Yu P , Novoseltsev A D 
Published: May 2020

Abstract
Samples of independent identically distributed random non-negative values

r
∼

1

,
…
,

r
∼

N

with a finite size

N
≥
2

are studied. It is posed the problem to find the sufficient conditions for their common probability distribution

Q
(
x
)
=
Pr
{

r
∼

j

<
x
}
,
j
=
1
÷
N

which guarantee the unimodality of the probability distributions

F
N

(
+
)

(
x
)
=
Pr
{

r
∼

+

<
x
}

and

F
N

(
−
)

(
x
)
=
Pr
{

r
∼

−

<
x
}

which correspond to the maximum

r
∼

+

=
max
{

r
∼

j

;
j
=
1
÷
N
}

and to the minimum

r
∼

−

=
max
{

r
∼

j

;
j
=
1
÷
N
}

of the sample, respectively. It is proved that if the distribution Q is determined by a continuously differentiable Erlang probability density q of an arbitrary order

n
∈

N

then distributions

F
N

(
±
)

are unimodal.
Analysis of the properties of OLS-estimates in parameter identification of distributed dynamic processes
Authors: Matveev M G , Sirota E A 
Published: May 2020

Abstract
This work is devoted to analysis and research of OLS-estimates properties when identifying parameters of distributed dynamic processes. The study showed that at a low level of observation errors (1% and lower), the use of direct OLS estimates to identify parameters of distributed dynamic processes gives satisfactory results. At the same time, the displacement value is always slightly higher than the value of the standard deviation of the parameter estimate, which does not allow to neglect the displacement, especially at a high and average level of observation errors. The method of obtaining so-called alternative OLS-estimates is also proposed, which allows to reduce multicollinearity in sample statistics and at any level of observation errors significantly reduce standard error of parameter estimation.
Application of a fundamental solution to a problem operator for modeling vibrations of elastically supported load-bearing structures
Authors: Skalko Yu I , Yu Gridnev S , Minaeva N V 
Published: May 2020

Abstract
The work is devoted to the construction of effective computational algorithms for modeling vibrations of elastically supported load-bearing systems. An approach is developed based on the representation of a mathematical model in the form of partial differential equations for generalized functions. With this approach, the presence of elements with a very high stiffness in the design made it necessary to carry out the calculation with a very small time step. To build a computational algorithm, a fundamental solution to the problem operator is used, which allows one to obtain a solution at the next time step for each point of the spatial grid independently. The need to carry out the calculation with a very small time step arises only in nodes that coincide with the location of structural elements with very high stiffness. The proposed approach allows simulating impact forces and instantaneous change of boundary conditions. The possibility of using the model with an absolutely rigid restraining support as a limit transition from a model of elastic bond of high rigidity was researched on.
Experimental estimation of channel width of IP BPX subscribers in OpenVPN IP networks
Authors: Telkov A Y , Olimpiev N V 
Published: May 2020

Abstract
This paper presents the methodology and results of an experimental estimation of the channel width required to transfer traffic from VoIP subscribers connected via VPN technology to IP ATC Asterisk. OpenVPN technology with typical settings (tun interfaces, routed network segments and TCP transport protocol) was used. An updated tool for estimating the volumes of transmitted and received traffic was used, based on data processing from the ipcad sensor — an emulator of the Cisco NetFlow mechanism for linux routers. The operator representation of extracting information about single network sessions is used.
The influence of friction on behavior of a hyperelastic body in a conic channel
Authors: Astapov Yuri , Markin Alexey 
Published: May 2020

Abstract
The model problem about the axisymmetric quasistatic motion of an elastic sphere considering the interaction with inner surface of a rigid cone die is investigated. The constitutive model is represented by the physically nonlinear generalization of the linear model of Hencky’s elastic material. The tensor of logarithmic strains is used by way of strain measure due to described below special properties. The influence of friction on macro characteristics of a process is studied using proposed numerical model of accounting of mixed boundary conditions on time-changing contact surface.
Analysis of non-uniform residual stress state in plates with in-plane and transverse heterogeneities
Authors: Nedin R 
Published: May 2020

Abstract
In the present paper, we describe a model of a prestressed inhomogeneous body and provide the variational and weak statements. On its basis, we study a problem of mixed vibrations of a non-uniform plate with inclusions and a sandwich-structured three-ply plate under the conditions of the residual stress-strain state. We build the numerical finite-element solution on the basis of the weak problem statement and analyze the effect of the prestress states on its frequency response functions. In addition, we identify the prestress level in the middle layer of the composite plate by the data on frequency characteristics measurements.
On quasi-linearization of correlations in quadratic elasticity theory for isotropic media
Authors: Matchenko N M 
Published: May 2020

Abstract
This paper exposes the strain potential of the quadratic theory of elasticity for isotropic media. The strain potential is represented as a sum of the quadratic and the cubic part. A system of experiments, carried out to define five constants included in the potential, is exposed. Different variants of building quasi-linear correlations are discussed. The rationality of linearizing constitutive correlations by reducing the degree of the potential’s cubic part by division by the quadratic convolution module of stress tensor components is doubted because the correlations thus found are lengthier than the correlations from the quadratic elasticity theory.
Vibrations of cylindrical shells with rectangular cross-section
Authors: Dzebisashvili G T , Filippov S B 
Published: May 2020

Abstract
The free vibrations of cylindrical shells with rectangular cross-section are studied in the work. The precision of Rayleigh method for various admissible functions and different boundary conditions is evaluated. Using finite element method, the natural frequencies in the case of deviation of the cross-section shape from square to rectangular are examined, and the vibration frequencies and modes for the shell joined with the plate are studied for various plate thicknesses. Additionally, fundamental frequency behavior is analyzed in the case of fixed support, as one of the cross-section sides approaches zero.
Simulation of pyrolysed polyacrylonitrile based composite with amorphising boron additives
Authors: Kakorina O A , Zaporotskova I V , Kakorin I A , Kozhitov L V 
Published: May 2020

Abstract
The paper deals with the possibility of modifying pyrolyzed polyacrylonitrile with amorphizing additives. Adsorption features of the boron atom on the surface of the monolayer of polymer are studied, and the geometric and electron-energy characteristics of the composite obtained are established. The calculations were performed using the semi-empirical MNDO method within the framework of the molecular cluster model.
Computational algorithms based on the fundamental solution of task operator
Authors: Skalko Yu I , Yu Gridnev S , Minaeva N V 
Published: May 2020

Abstract
An approximation of matrix Green’s function for a hyperbolic system of linear differential equations of the first order has been created. An algorithm for an approximate solution of the generalized Riemann problem of discontinuity decay in the presence of additional conditions at the boundaries has been proposed. A computational algorithm for the approximate solution of boundary value problems for hyperbolic systems of equations has been set up on the basis of these solutions. The algorithm is implemented for a system of equations describing the propagation of elastic waves in a block-fractured medium. The results of the numerical experiments aimed at studying the possible mechanisms of propagation of elastic waves to a considerable depth without scattering have been presented.
Experimental Investigations of Enhanced Micro Structured Heat Sinks
Authors: Hadi Ammar M. , Ismael Muneer A. , Sadiq Maher A.R. , Alhattab Haider A. 
Published: May 2020

Abstract
In this research, we focus on the performance of heat sink, new configurations of the micro heat sink with comprises of pinned copper pieces of appropriate dimensions have been proposed. Dozens of different shapes micro heat sinks have been manufactured from brass using Laser technique. These heat sinks have been coupled individually with a simulated electronic circuit including a power transistor to freely dissipate the generated heat. Bulk temperatures of heat sink and the power transistor have been measured using a thermal camera. The results showed that, in general, the finned heat sink of either configuration augments heat transfer compared with smooth one. It is found that the maximum percentage reductions in temperature of the transistor are demonstrated with two uncommon configurations, namely the leaves-shaped fin (LSF) 9.352% and the drop-shaped fin (DSF) 9.353%. on the other hand, a staggered wavy fin (SWF) shows minimum percentage reduction in transistor temperature, 0.952%. It has been shown that through this research and by using several models of heat sink, the increase in surface area is not only the factor (major) to increase the heat transfer to the surrounding environment. This makes it possible to design fins with a smaller surface area but more heat dispersionIn this research, we focus on the performance of heat sink, new configurations of the micro heat sink with comprises of pinned copper pieces of appropriate dimensions have been proposed. Dozens of different shapes micro heat sinks have been manufactured from brass using Laser technique. These heat sinks have been coupled individually with a simulated electronic circuit including a power transistor to freely dissipate the generated heat. Bulk temperatures of heat sink and the power transistor have been measured using a thermal camera. The results showed that, in general, the finned heat sink of either configuration augments heat transfer compared with smooth one. It is found that the maximum percentage reductions in temperature of the transistor are demonstrated with two uncommon configurations, namely the leaves-shaped fin (LSF) 9.352% and the drop-shaped fin (DSF) 9.353%. on the other hand, a staggered wavy fin (SWF) shows minimum percentage reduction in transistor temperature, 0.952%. It has been shown that through this research and by using several models of heat sink, the increase in surface area is not only the factor (major) to increase the heat transfer to the surrounding environment. This makes it possible to design fins with a smaller surface area but more heat dispersion.
Pilgrims tracking and monitoring based on IoT
Authors: Issam Younis Mohammed , Hashim Abdulkareem Mustafa 
Published: May 2020

AbstractThe pilgrimage takes place in several countries around the world. The pilgrimage includes the simultaneous movement of a huge crowd of pilgrims which leads to many challenges for the pilgrimage authorities to track, monitor, and manage the crowd to minimize the chance of overcrowding’s accidents. Therefore, there is a need for an efficient monitoring and tracking system for pilgrims. This paper proposes powerful pilgrims tracking and monitoring system based on three Internet of Things (IoT) technologies; namely: Radio Frequency Identification (RFID), ZigBee, and Internet Protocol version 6 (IPv6). In addition, it requires low-cost, low-power-consumption implementation. The proposed system can efficiently handle the pilgrimage challenges; namely: the language barrier, identifying of injured or dead pilgrims, directing lost pilgrims, knowing medical records of pilgrims, and the crowd management. Finally, another paramount characteristic of the proposed IoT-based system is allowing the authorities, the heath-givers, and the pilgrim’s family for real-time tracking and monitoring of pilgrim during the pilgrimage anytime, anywhere.