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Algorithm for solving the knapsack problem with certain properties of Pareto layers 具有帕累托层某些性质的背包问题的求解算法
Q4 Mathematics Pub Date : 2022-12-27 DOI: 10.33581/2520-6508-2022-3-54-66
S. V. Chebakov, L. V. Serebryanaya
An algorithm for solving the knapsack problem based on the proposed multicriteria model has been developed. The structure of admissible subsets is presented for the value of the non-dominance depth of the Pareto layer equal to zero. The sum of the resource of the elements of this layer is greater than or equal to the value of the volume of the knapsack. Based on the structure, the form of the optimal admissible subset with the maximum total value of the weight of its elements is determined. It is shown that at a certain stage the developed algorithm includes the solution of a number of knapsack subtasks. Their knapsack volumes are smaller than in the original problem with input data sets. The definition of the redundancy of the set of initial data and the condition for the existence of redundancy for a given value of the depth of non-dominance of the Pareto layer are introduced.
基于所提出的多准则模型,提出了一种求解背包问题的算法。给出了Pareto层非优势深度为零时的容许子集结构。这一层元素资源的总和大于或等于背包的体积值。在此基础上,确定了最优容许子集的形式,其元素的总权重最大。结果表明,在一定阶段,所开发的算法包含了许多背包子任务的求解。他们的背包体积比输入数据集的原始问题要小。引入了初始数据集冗余的定义和给定帕累托层非支配深度值时冗余存在的条件。
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引用次数: 0
Numerical study of the relative equilibrium of a droplet with a simply connected free surface on a rotating plane 旋转平面上具有单连通自由表面的液滴相对平衡的数值研究
Q4 Mathematics Pub Date : 2022-12-26 DOI: 10.33581/2520-6508-2022-3-79-90
Yauheni V. Audzeichyk, P. Konon
The paper investigates the shapes of relative rest of limited layers of liquid on a rotating horizontal plane in the field of gravity in the presence of surface tension. The layers under consideration have a simply connected free surface and rotational symmetry with respect to the line of action of the angular velocity. The mathematical formulation of this problem is reduced to a system of first-order ordinary differential equations with boundary and integral closing conditions. A new algorithm for the numerical solution of the resulting system is proposed, the influence of various dimensionless parameters on the characteristics of equilibrium droplet shapes is studied, and criteria for the existence of such shapes are determined. The paper is of theoretical interest, since the problem under consideration is one of the fundamental ones in the research of capillary phenomena. The developed numerical scheme can also be applied in a wider class of differential equations. The results of the article can be used in practical tasks related to coating, fiber and powder production by the centrifugal-disk method.
本文研究了在重力场中存在表面张力时旋转水平面上有限液体层的相对静止形状。所考虑的层具有单连通的自由表面和相对于角速度作用线的旋转对称。将该问题的数学形式简化为具有边界和积分闭合条件的一阶常微分方程组。提出了一种新的数值解算法,研究了各种无量纲参数对平衡液滴形状特征的影响,并确定了平衡液滴形状存在的判据。这篇论文具有理论意义,因为所考虑的问题是毛细现象研究中的一个基本问题。所开发的数值格式也可以应用于更广泛的微分方程。本文的研究结果可用于离心圆盘法生产涂料、纤维和粉末的实际工作中。
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引用次数: 0
On the Hosoya polynomial of the third type of the chain hex-derived network 关于第三类链十六进制网络的Hosoya多项式
Q4 Mathematics Pub Date : 2022-12-23 DOI: 10.33581/2520-6508-2022-3-67-78
Shibsankar Das, S. Rai
A topological index plays an important role in characterising various physical properties, biological activities, and chemical reactivities of a molecular graph. The Hosoya polynomial is used to evaluate the distance-based topological indices such as the Wiener index, hyper-Wiener index, Harary index, and Tratch – Stankevitch – Zefirov index. In the present study, we determine a closed form of the Hosoya polynomial for the third type of the chain hex-derived network of dimension n and derive the distance-based topological indices of the network with the help of their direct formulas and alternatively via using the obtained Hosoya polynomial. Finally, we graphically represent the computed distance-based topological indices and the Hosoya polynomial of the underlying network to comprehend their geometrical pattern. This study of the Hosoya polynomial and the corresponding indices can set the basis for more exploration into chain hex-derived networks and their properties.
拓扑指数在表征分子图的各种物理性质、生物活性和化学反应性方面发挥着重要作用。Hosoya多项式用于评估基于距离的拓扑指数,如维纳指数、超维纳指数、Harary指数和Tratch–Stankevitch–Zefirov指数。在本研究中,我们确定了第三类维数为n的链十六进制导出网络的Hosoya多项式的闭合形式,并借助于它们的直接公式和使用所获得的Hosoye多项式来导出网络的基于距离的拓扑指数。最后,我们用图形表示计算出的基于距离的拓扑指数和底层网络的Hosoya多项式,以理解它们的几何模式。Hosoya多项式及其相应指数的研究可以为进一步探索链十六进制网络及其性质奠定基础。
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引用次数: 0
Algebraic equations and polynomials over the ring of p-complex numbers p复数环上的代数方程和多项式
Q4 Mathematics Pub Date : 2022-12-21 DOI: 10.33581/2520-6508-2022-3-37-44
V. V. Dovgodilin
In this paper, we study the algebraic equations over the ring of p-complex numbers. Remainder division theorems and an analogue of Bezout’s theorem for p-complex polynomials are represented. For equations of the 2nd and 3rd degrees, conditions for the existence of roots are obtained, in some cases solutions are given in an explicit form. For polynomials of an arbitrary degree with an invertible leading coefficient, theorems on factorisation with a unit leading coefficient are proven in the cases where there are simple roots, multiple roots, and no roots. It is shown that in the absence of multiple roots, this decomposition will be unique, and in the case of the presence of multiple roots, the polynomial admits an infinite number of expansions.
本文研究了p复数环上的代数方程。给出了p复多项式的剩余除法定理和Bezout定理的一个类比。对于二阶和三次方程,得到了根存在的条件,在某些情况下给出了解的显式形式。对于导系数可逆的任意次多项式,分别在单根、复根和无根情况下证明了导系数为单位的分解定理。证明了在没有多重根的情况下,这个分解是唯一的,并且在有多重根的情况下,多项式允许无限次展开。
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引用次数: 0
On the theory of operator interpolation in spaces of rectangular matrixes 矩形矩阵空间中的算子插值理论
Q4 Mathematics Pub Date : 2022-12-19 DOI: 10.33581/2520-6508-2022-3-91-106
M. V. Ignatenko, L. Yanovich
The problem of constructing and studying interpolation operator polynomials of an arbitrary fixed degree, defined in spaces of rectangular matrices, which would be generalisations of the corresponding interpolation formulas in the case of square matrices, is considered. Linear interpolation formulas of various structures are constructed for rectangular matrices. Matrix polynomials, with respect to which the resulting interpolation formulas are invariant, are indicated. As a generalisation of linear formulas, formulas for quadratic interpolation and interpolation by polynomials of arbitrary fixed degree in the space of rectangular matrices are constructed. Particular cases of the obtained formulas are considered: when square matrices are chosen as nodes or when the values of the interpolated function are square matrices, as well as the case when both of these conditions are satisfied. For the last variant, the possibilities of different and identical matrix orders for nodes and function values are explored. The obtained results are based on the application of some well-known provisions of the theory of matrices and the theory of interpolation of scalar functions. The presentation of the material is illustrated by a number of examples.
考虑了在矩形矩阵空间中定义的任意固定次数的插值算子多项式的构造和研究问题,该多项式将是正方形矩阵情况下相应插值公式的推广。构造了矩形矩阵的各种结构的线性插值公式。给出了矩阵多项式,其插值公式是不变的。作为线性公式的推广,构造了矩形矩阵空间中任意定次多项式的二次插值和插值公式。考虑了所获得公式的特殊情况:当选择正方形矩阵作为节点时,或当插值函数的值是正方形矩阵时,以及当这两个条件都满足时的情况。对于最后一种变体,探索了节点和函数值的不同和相同矩阵阶的可能性。所得到的结果是基于矩阵理论和标量函数插值理论中一些著名条款的应用。材料的介绍通过一些例子加以说明。
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引用次数: 0
Pseudo-prolongations in the qualitative theory of dynamical systems 动力学系统定性理论中的伪延拓
Q4 Mathematics Pub Date : 2022-12-16 DOI: 10.33581/2520-6508-2022-3-45-53
B. Kalitine
This paper considers the qualitative behaviour of the flow in a neighbourhood of closed invariant sets of dynamical systems. The properties of compactness, invariance, and connectivity of pseudo-prolongations are investigated. A rather deep analysis of the flow in the vicinity of a compact invariant set of asymptotically compact phase spaces is presented. The connection of pseudo-prolongation with the first positive prolongation of T. Ura and the set of weakly elliptic points is refined.
本文研究了动力系统闭不变集邻域中流动的定性行为。研究了伪延拓的紧性、不变性和连通性的性质。对渐近紧致相空间的紧致不变集附近的流进行了相当深入的分析。对T.Ura的第一个正延拓与弱椭圆点集的伪延拓的联系进行了精化。
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引用次数: 0
Hypersingular integro-differential equation with recurrent relations in coefficients 系数递推关系的超奇异积分-微分方程
Q4 Mathematics Pub Date : 2022-12-13 DOI: 10.33581/2520-6508-2022-3-6-15
A. P. Shilin
A new hypersingular integro-differential equation is considered on a closed curve located on the complex plane. The equation refers to linear equations with variable coefficients of a special kind. A characteristic feature is the presence of constant multipliers in the coefficients, given by some recurrent relations. The equation is first reduced to solving the Riemann boundary value problem on the original curve. A class of functions is established for solving the Riemann problem, after which this problem is solved. Next, it is necessary to solve two linear differential equations of arbitrary order for analytical functions in two different regions of the complex plane. The corresponding fundamental systems of solutions are found, after which the method of variation of arbitrary constants is used for the solution. Restrictions are imposed on the obtained solutions of differential equations in order to achieve their analyticity. As a result, all the resulting solvability conditions of the original equation are written explicitly. The solution of the original equation after solving the differential equations can be written explicitly. Solved the example.
在复平面上的闭合曲线上,研究了一类新的超奇异积分-微分方程。该方程是指一类特殊的变系数线性方程。一个特征是系数中存在常数乘子,由一些递归关系给出。首先将方程简化为解原曲线上的黎曼边值问题。建立了求解黎曼问题的一类函数,然后求解了黎曼问题。其次,需要在复平面的两个不同区域上解两个任意阶的解析函数线性微分方程。找到了相应的基本方程组的解,然后用任意常数变分法求解。为了实现微分方程的解析性,对得到的解进行了限制。由此,得到了原方程的所有可解条件。解微分方程后,可以显式地写出原方程的解。解出了这个例子。
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引用次数: 0
Application of the real Hardy – Sobolev space on the line to study the order of uniform rational approximations of functions 应用实Hardy - Sobolev空间在直线上研究函数一致有理逼近的阶数
Q4 Mathematics Pub Date : 2022-12-12 DOI: 10.33581/2520-6508-2022-3-16-36
Tatsiana S. Mardvilko, Aleksandr A. Pekarskii
The real space of Hardy – Sobolev on a straight line is considered and some sufficient conditions for belonging to functions to this space are described. Estimates of the norm of functions from this space are also obtained. Various examples of functions from the Hardy – Sobolev space are given and the order of their best uniform rational approximations are investigated. Estimates of the best rational approximations for even and odd continuations of functions with monotonous derivatives are obtained. The order of the best rational approximations of the even and odd continuations of functions in the general case have also been studied. Estimates are given both considering the continuity module and without it. The obtained results are also used to study the best rational approximations of functions with a kink, introduced by A. A. Gonchar.
考虑了Hardy–Sobolev在直线上的实空间,给出了函数属于该空间的一些充分条件。从这个空间也得到了函数范数的估计。给出了Hardy–Sobolev空间中函数的各种例子,并研究了它们的最佳一致有理逼近的阶数。得到了具有单调导数的函数的偶和奇连续的最佳有理逼近的估计。研究了在一般情况下函数偶和奇连续的最佳有理逼近的阶。给出了考虑连续模和不考虑连续模的估计。所得结果还用于研究a.a.Gonchar提出的带扭结函数的最佳有理逼近。
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引用次数: 0
Mathematical modelling of salt ion transfer in the three-dimensional desalting channel of an electrodialysis apparatus 电渗析装置三维脱盐通道中盐离子转移的数学模型
Q4 Mathematics Pub Date : 2022-08-03 DOI: 10.33581/2520-6508-2022-2-70-81
A. Kovalenko, A. Ovsyannikova
A new 3D model of 1:1 salt ion transfer in the desalting channel of an electrodialysis apparatus is presented and investigated in this paper. For the first time a three-dimensional mathematical model of salt ion transfer in the desalting channel taking into account the electroconvection based on the system of Nernst – Planck, Poisson and Navier – Stokes equations with the electric force and the natural boundary conditions is proposed. To solve the boundary value problem, the finite element method is used in the cross-platform numerical analysis software COMSOL Multiphysics in combination with the method of successive approximations, when the electrochemical and hydrodynamic parts of the problem are solved one by one on the current layer. In turn, the electrochemical and hydrodynamic parts of the problem are solved by Newton’s method. As a result of numerical analysis, the fundamental regularities of salt ion transfer in a three-dimensional channel, the emergence and development of electroconvective vortices, including the discovery of new three-dimensional spiral forms of salt ions, are established for the first time. It is shown that electroconvective vortices exist in the form of clusters, within which vortex bifurcations can occur. Thus, the currently existing simplified view of the structure of electroconvective vortices is clarified and developed.
本文提出并研究了电渗析装置脱盐通道中1:1盐离子转移的三维模型。本文首次提出了考虑电对流的脱盐通道中盐离子转移的三维数学模型,该模型基于能思-普朗克、泊松和纳维-斯托克斯方程组,考虑电场力和自然边界条件。为了求解边值问题,在跨平台数值分析软件COMSOL Multiphysics中,结合逐次逼近法,在电流层上逐个求解问题的电化学部分和流体动力部分。然后,用牛顿法求解了问题的电化学和流体力学部分。通过数值分析,首次确立了盐离子在三维通道中转移的基本规律,电对流涡的产生和发展,包括盐离子新的三维螺旋形式的发现。结果表明,电对流涡旋以团簇的形式存在,团簇内可发生涡旋分岔。从而澄清和发展了现有的关于电对流涡结构的简化观点。
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引用次数: 0
Detection of human body parts on the image using the neural networks and the attention model 利用神经网络和注意力模型检测图像上的人体部位
Q4 Mathematics Pub Date : 2022-08-03 DOI: 10.33581/2520-6508-2022-2-94-106
V. Sorokina, S. Ablameyko
Human body parts detection is a challenging task, which has a lot of applications. In this paper, we propose an algorithm to detect human body parts on images using the OpenPose neural network and the attention model. The novelty of the proposed algorithm is that it is based on a convolutional neural network that uses non-parametric representation to associate the body parts with people in an image in combination with the attention model that learns to focus on specific regions of the input image. The algorithm is part of the Smart Cropping system developed by the authors with the aim to cut necessary pieces of clothing in images and prepare e-commerce catalogues.
人体部位检测是一项具有挑战性的任务,有很多应用。在本文中,我们提出了一种使用OpenPose神经网络和注意力模型在图像上检测人体部位的算法。所提出的算法的新颖性在于,它基于卷积神经网络,该网络使用非参数表示将身体部位与图像中的人相关联,并结合学习关注输入图像的特定区域的注意力模型。该算法是作者开发的智能裁剪系统的一部分,目的是在图像中裁剪必要的衣服,并准备电子商务目录。
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引用次数: 1
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Zhurnal Belorusskogo Gosudarstvennogo Universiteta. Matematika. Informatika
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