Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva最新文献_第9页

The nonlocal solvability conditions for a system of two quasilinear equations of the first order with absolute terms 具有绝对项的两个一阶拟线性方程组的非局部可解性条件

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-09-30 DOI: 10.15507/2079-6900.21.201903.317-328

M. Dontsova

引用次数: 1

The flow of a viscous fluid with a predetermined pressure gradient through periodic structures 具有预定压力梯度的粘性流体通过周期性结构的流动

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.222-243

M. S. Deryabina, S. I. Martynov

{"title":"The flow of a viscous fluid with a predetermined pressure gradient through periodic structures","authors":"M. S. Deryabina, S. I. Martynov","doi":"10.15507/2079-6900.21.201902.222-243","DOIUrl":"https://doi.org/10.15507/2079-6900.21.201902.222-243","url":null,"abstract":"In the Stokes approximation, the problem of viscous fluid flow through two-dimensional and three-dimensional periodic structures is solved. A system of thin plates of a finite width is considered as a two-dimensional structure, and a system of thin rods of finite length is considered as a three-dimensional structure. Plates and rods are periodically located in space with certain translation steps along mutually perpendicular axes. On the basis of the procedure developed earlier, the authors constructed an approximate solution of the equations for fluid flow with an arbitrary orientation of structures relative to a given vector of pressure gradient. The solution is sought in a finite region (cells) around inclusions in the class of piecewise smooth functions that are infinitely differentiable in the cell, and at the cell boundaries they satisfy the continuity conditions for velocity, normal and tangential stresses. Since the boundary value problem for the Laplace equation is solved, it is assumed that the solution found is unique. The type of functions allows us to separate the variables and to reduce the problem's solution to the solution of ordinary differential equations. It is found that the change in the flow rate of a fluid through a characteristic cross section is determined mainly by the geometric dimensions of the cells of the free liquid in such structures and is practically independent of the size of the plates or rods.","PeriodicalId":273445,"journal":{"name":"Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122400195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Review of the works of V. N. Shchennikova on the study of the convergence of nonlinear almost periodic systems by the comparison method 综述了V. N. Shchennikova用比较方法研究非线性概周期系统收敛性的工作

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.175-186

A. Kosov, A. V. Shchennikov, E. V. Shchennikova, R. V. Zhalnin, P. A. Shamanaev

引用次数: 0

Application of discontinuous Galerkin method to modeling of two-dimensional flows of a multicomponent ideal gases mixture using local adaptive mesh refinement 局部自适应网格细化的不连续伽辽金方法在多组分理想气体混合物二维流动建模中的应用

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.244-258

R. V. Zhalnin, V. F. Masyagin, E. E. Peskova, V. Tishkin

引用次数: 0

On periodic mapping data of a two-dimensional torus with one saddle orbit 二维单鞍轨道环面的周期映射数据

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.164-174

A. A. Bosova, O. Pochinka

{"title":"On periodic mapping data of a two-dimensional torus with one saddle orbit","authors":"A. A. Bosova, O. Pochinka","doi":"10.15507/2079-6900.21.201902.164-174","DOIUrl":"https://doi.org/10.15507/2079-6900.21.201902.164-174","url":null,"abstract":"Periodic data of diffeomorphisms with regular dynamics on surfaces were studied using zeta functions in a series of already classical works by such authors as P. Blanchard, J. Franks, S. Narasimhan, S. Batterson and others. The description of periodic data for gradient-like diffeomorphisms of surfaces were given in the work of A. Bezdenezhnykh and V. Grines by means of the classification of periodic surface transformations obtained by J. Nielsen. V. Grines, O. Pochinka, S. Van Strien showed that the topological classification of arbitrary Morse-Smale diffeomorphisms on surfaces is based on the problem of calculating periodic data of diffeomorphisms with a single saddle periodic orbit. Namely, the construction of filtering for Morse-Smale diffeomorphisms makes it possible to reduce the problem of studying periodic surface diffeomorphism data to the problem of calculating periodic diffeomorphism data with a single saddle periodic orbit. T. Medvedev, E. Nozdrinova, O. Pochinka solved this problem in a general formulation, that is, the periods of source orbits are calculated from a known period of the sink and saddle orbits. However, these formulas do not allow to determine the feasibility of the obtained periodic data on the surface of this kind. In an exhaustive way, the realizability problem is solved only on a sphere. In this paper we establish a complete list of periodic data of diffeomorphisms of a two-dimensional torus with one saddle orbit, provided that at least one nodal point of the map is fixed.","PeriodicalId":273445,"journal":{"name":"Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127801223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the approximate method for determination of heat conduction coefficient 关于确定热传导系数的近似方法

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.149-163

I. V. Boikov, V. Ryazantsev

{"title":"On the approximate method for determination of heat conduction coefficient","authors":"I. V. Boikov, V. Ryazantsev","doi":"10.15507/2079-6900.21.201902.149-163","DOIUrl":"https://doi.org/10.15507/2079-6900.21.201902.149-163","url":null,"abstract":"The problem of recovering a value of the constant coefficient in heat equation for one- and two-dimensional cases is considered in the paper. This inverse coefficient problem has broad range of applications in physics and engineering, in particular, for modelling heat exchange processes and for studying properties of materials and designing of engineering constructions. In order to solve the problem an approximate method is constructed; it is based on the continuous operator method for solving nonlinear equations. The advantages of the proposed method are its simplicity and universality. The last property allows to apply the method to a wide range of problems. In particular, in constructing and justifying a continuous operator method, in contrast to the Newton–Kantorovich method, the continuous reversibility of Frechet or Gato derivatives is not required. Moreover, derivatives may not exist on sets of measure zero. The application of continuous operator method to the solution of an inverse coefficient problem with a constant coefficient makes it possible to minimize additional conditions -- there is enough information about the exact solution at a single point x∗,t∗. Solving several model problems illustrates the high efficiency of the proposed method.","PeriodicalId":273445,"journal":{"name":"Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122977360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An approximation of problems of optimal control on the coefficients of elliptic convection-diffusion equations with an imperfect contact matching condition 具有不完全接触匹配条件的椭圆型对流扩散方程系数最优控制问题的逼近

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.187-214

Fedor F. Lubyshev, A. Manapova

{"title":"An approximation of problems of optimal control on the coefficients of elliptic convection-diffusion equations with an imperfect contact matching condition","authors":"Fedor F. Lubyshev, A. Manapova","doi":"10.15507/2079-6900.21.201902.187-214","DOIUrl":"https://doi.org/10.15507/2079-6900.21.201902.187-214","url":null,"abstract":"We consider nonlinear optimization problems for processes described by non-self-adjoint elliptic equations of convection-diffusion problems with an imperfect contact matching conditions. These are the problems with a jump of the coefficients and of the solution on the interface; the jump of the solution is proportional to the normal component of the flux. Variable coefficients multiplying the highest and the lowest derivatives in the equation and the coefficients by nonlinear terms in the equations of state are used as controls. Finite difference approximations of optimization problems are constructed and investigated. For the approximation of state equations we propose a new ``modified difference scheme'' in which the variable grid coefficients in the principal part of the difference operator are computed using method other than traditionally applied in the theory of difference schemes. The problem's correctness is investigated. The accuracy estimation of difference approximations with respect to the state are obtained. Convergence rate of approximations with respect to cost functional is estimated, too. Weak convergence with respect to control is proved. The presence of a non-self-adjoint operator causes certain difficulties in constructing and studying approximations of differential equations describing discontinuous states of controlled processes, in particular, in proving the difference approximations well-posedness, and in studying the relationship between the original optimal control problem and the approximate mesh problem. The approximations are regularized. The obtained results will be heavily used later in solving problems associated with the development of effective methods for the numerical solution to the constructed finite-dimensional mesh optimal control problems and their computer implementation.","PeriodicalId":273445,"journal":{"name":"Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva","volume":"201 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123027842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Empirical and physics-based approaches to estimate states of lithium-ion battery 基于经验和物理的锂离子电池状态估计方法

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-06-30 DOI: 10.15507/2079-6900.21.201902.259-268

A. A. Fedorova

引用次数: 0

The ill-posed problem for the heat transfer equation with involution 对合传热方程的不适定问题

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-03-30 DOI: 10.15507/2079-6900.21.201901.48-59

A. Sarsenbi

引用次数: 1

Robust trajectory tracking control of omni-mobile robot with slipping of the wheels 考虑车轮滑动的全移动机器人鲁棒轨迹跟踪控制

Zhurnal Srednevolzhskogo Matematicheskogo Obshchestva Pub Date : 2019-03-30 DOI: 10.15507/2079-6900.21.201901.13-23

A. Andreev, O. Peregudova

引用次数: 0