发布求助
文献互助 智能选刊 最新文献

Russian Journal of Numerical Analysis and Mathematical Modelling最新文献

筛选
英文 中文
Mathematical modelling for spatial optimization of irradiation during proton radiotherapy with nanosensitizers 纳米致敏剂质子放射治疗中辐照空间优化的数学建模
4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-10-01 DOI: 10.1515/rnam-2023-0023
Maxim Kuznetsov, Andrey Kolobov
{"title":"Mathematical modelling for spatial optimization of irradiation during proton radiotherapy with nanosensitizers","authors":"Maxim Kuznetsov, Andrey Kolobov","doi":"10.1515/rnam-2023-0023","DOIUrl":"https://doi.org/10.1515/rnam-2023-0023","url":null,"abstract":"Abstract A spatially distributed mathematical model is presented that simulates the growth of a non-invasive tumour undergoing treatment by fractionated proton therapy with the use of non-radioactive tumour-specific nanosensitizers. Nanosensitizers are injected intravenously before each irradiation to increase the locally deposited dose via a chain of reactions with therapeutic protons. Modelling simulations show that the use of nanosensitizers allows increasing treatment efficacy. However, their effect is restricted by the necessity of decreasing the energy deposited in tumour in order to comply to the normal damage restrictions. Normalization of tumour microvasculature that accompanies the treatment, also compromises nanosensitizers effect as it impairs their inflow in tumour. It is shown that spatial optimization of irradiation, with conservation of total dose deposited in tumour, can increase tumour cell damage for each single irradiation. However, eventually it may not lead to the overall increase of treatment efficacy, in terms of minimization of the number of remaining viable tumour cells, due to the influence of tumour cell repopulation between irradiations. It is suggested that an efficient way towards minimization of tumour cell repopulation may be the faster suppression of angiogenesis by eradication of metabolically deprived tumour cells. This method can be efficient even despite the fact that it would also cause the decrease of supply of nanosensitizers into the tumour.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136198949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Pressure-correction projection method for modelling the incompressible fluid flow in porous media 多孔介质中不可压缩流体流动模型的压力修正投影法
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-0019
K. Terekhov
{"title":"Pressure-correction projection method for modelling the incompressible fluid flow in porous media","authors":"K. Terekhov","doi":"10.1515/rnam-2023-0019","DOIUrl":"https://doi.org/10.1515/rnam-2023-0019","url":null,"abstract":"Abstract This work is dedicated to the pressure-correction projection method for the volume-averaged Navier–Stokes system for porous media. A set of parameters controlling the presence of inertia and viscosity is introduced into the system. Switching parameters allows us to reduce the system to either the Brinkman system or the Darcy equation. Considering the jump in the parameters between mesh cells allows capturing the contact of media of different types, such as free-flow and porous media flow. We apply Chorin’s projection method to decouple the system. The splitting of the system yields a momentum conservation equation and an anisotropic pressure correction equation. We propose a combination of collocated finite-volume methods to solve the problem.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46895771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Multicontinuum homogenization for Richards’ equation: The derivation and numerical experiments 理查兹方程的多连续统均匀化:推导与数值实验
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-0016
D. Ammosov, S. Stepanov, D. Spiridonov, Wenyuan Li
{"title":"Multicontinuum homogenization for Richards’ equation: The derivation and numerical experiments","authors":"D. Ammosov, S. Stepanov, D. Spiridonov, Wenyuan Li","doi":"10.1515/rnam-2023-0016","DOIUrl":"https://doi.org/10.1515/rnam-2023-0016","url":null,"abstract":"Abstract In the present paper, the authors rigorously derive Richards’ multicontinuum model using the multicontinuum homogenization approach. This approach is based on formulating constraint cell problems and a homogenization-like expansion. We present numerical results for the two continua case with separable coefficients. First, we explore the relationships between the effective coefficients and the hydraulic conductivity. Then, we solve test problems with different contrasts to study the developed multicontinuum model.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47603539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Frontmatter 头版头条
4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-frontmatter4
{"title":"Frontmatter","authors":"","doi":"10.1515/rnam-2023-frontmatter4","DOIUrl":"https://doi.org/10.1515/rnam-2023-frontmatter4","url":null,"abstract":"","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136106839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Operator-difference schemes on non-uniform grids for second-order evolutionary equations 二阶演化方程非均匀网格上的算子差分格式
4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-0020
Petr N. Vabishchevich
{"title":"Operator-difference schemes on non-uniform grids for second-order evolutionary equations","authors":"Petr N. Vabishchevich","doi":"10.1515/rnam-2023-0020","DOIUrl":"https://doi.org/10.1515/rnam-2023-0020","url":null,"abstract":"Abstract The approximate solution of the Cauchy problem for second-order evolution equations is performed, first of all, using three-level time approximations. Such approximations are easily constructed and relatively uncomplicated to investigate when using uniform time grids. When solving applied problems numerically, we should focus on approximations with variable time steps. When using multilevel schemes on non-uniform grids, we should maintain accuracy by choosing appropriate approximations and ensuring stability of the approximate solution. In this paper, we construct unconditionally stable schemes of the first- and second-order accuracy on a non-uniform time grid for the approximate solution of the Cauchy problem for a second-order evolutionary equation. The novelty of the paper consists in the fact that these stability estimates are obtained without any restrictions on the magnitude of the step change and on the number of step changes. We use a special transformation of the original second-order differential-operator equation to a system of first-order equations. For the system of first-order equations, we apply standard two-level time approximations. We obtained stability estimates for the initial data and the right-hand side in finite-dimensional Hilbert space. Eliminating auxiliary variables leads to three-level schemes for the initial second-order evolution equation. Numerical experiments were performed for the test problem for a one-dimensional in space bi-parabolic equation. The accuracy and stability properties of the constructed schemes are demonstrated on non-uniform grids with randomly varying grid steps.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136106961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The group behaviour modelling of workers in the labor market 劳动力市场中工人的群体行为模型
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-0017
A. Shananin, N. Trusov
{"title":"The group behaviour modelling of workers in the labor market","authors":"A. Shananin, N. Trusov","doi":"10.1515/rnam-2023-0017","DOIUrl":"https://doi.org/10.1515/rnam-2023-0017","url":null,"abstract":"Abstract We describe the mathematical modelling of the group behaviour of workers in the labor market. The worker receives the salary and seeks to improve his qualifications in order to receive higher wages. The worker enlarges his qualification by the investments in human capital. At a random moment of time, a vacancy appears that provides a jump in the worker’s salary. The mathematical model of the worker’s behaviour in the labor market is presented as an optimal control problem on an infinite time horizon. The paper presents the derivation of the Kolmogorov–Fokker–Planck equation for the Lévy process, which describes the behaviour of a large amount of workers within a social layer. The numerical solution of the Kolmogorov–Fokker–Planck equation and the calculation results are presented.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46830594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Study of performance of low-rank nonnegative tensor factorization methods 低秩非负张量分解方法的性能研究
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-08-01 DOI: 10.1515/rnam-2023-0018
E. Shcherbakova, S. Matveev, A. Smirnov, E. Tyrtyshnikov
{"title":"Study of performance of low-rank nonnegative tensor factorization methods","authors":"E. Shcherbakova, S. Matveev, A. Smirnov, E. Tyrtyshnikov","doi":"10.1515/rnam-2023-0018","DOIUrl":"https://doi.org/10.1515/rnam-2023-0018","url":null,"abstract":"Abstract In the present paper we compare two different iterative approaches to constructing nonnegative tensor train and Tucker decompositions. The first approach is based on idea of alternating projections and randomized sketching for factorization of tensors with nonnegative elements. This approach can be useful for both TT and Tucker formats. The second approach consists of two stages. At the first stage we find the unconstrained tensor train decomposition for the target array. At the second stage we use this initial approximation in order to fix it within moderate number of operations and obtain the factorization with nonnegative factors either in tensor train or Tucker model. We study the performance of these methods for both synthetic data and hyper-spectral image and demonstrate the clear advantage of the latter technique in terms of computational time and wider range of possible applications.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46211072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Particle tracking for face-based flux data on general polyhedral grids with applications to groundwater flow modelling 一般多面体网格上基于人脸流量数据的粒子跟踪及其在地下水流动建模中的应用
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-06-01 DOI: 10.1515/rnam-2023-0010
I. Kapyrin
{"title":"Particle tracking for face-based flux data on general polyhedral grids with applications to groundwater flow modelling","authors":"I. Kapyrin","doi":"10.1515/rnam-2023-0010","DOIUrl":"https://doi.org/10.1515/rnam-2023-0010","url":null,"abstract":"Abstract A particle tracking method based on face fluxes data calculated using finite volume methods is developed for unstructured three-dimensional polyhedral grids. The flow velocity field reconstruction on grid cells using a mixed finite element method is proposed. Cases of sinks and sources in cells as well as different cell partitionings are considered. Algorithms for streamlines and time of flight calculation are provided. Performance and convergence of the method are demonstrated on a set of reference problems.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49449819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
CarNum: parallel numerical framework for computational cardiac electromechanics CarNum：计算心脏机电学的并行数值框架
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-06-01 DOI: 10.1515/rnam-2023-0011
A. Liogky, A. Chernyshenko, A. Danilov, Fyodor A. Syomin
{"title":"CarNum: parallel numerical framework for computational cardiac electromechanics","authors":"A. Liogky, A. Chernyshenko, A. Danilov, Fyodor A. Syomin","doi":"10.1515/rnam-2023-0011","DOIUrl":"https://doi.org/10.1515/rnam-2023-0011","url":null,"abstract":"Abstract A new parallel numerical framework CarNum is presented for efficient coupling of mathematical models in multiphysics problems such as computational cardiac electromechanics. This framework is based on open source projects, which provide the core functionality of the platform. Computational cardiac electromechanics requires a complex pipeline of solving different types of ordinary and partial differential equations. Our framework allows one to implement different numerical schemes and provides more control in multiphysics coupling. This paper outlines a concept of the new platform and details of numerical modelling of cardiac electromechanics. First experiments with well-known cardiac electromechanics benchmarks show good agreement with other groups and decent parallel scalability.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47658149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
SIMUG – finite element model of sea ice dynamics on triangular grid in local Cartesian basis SIMUG–基于局部笛卡尔坐标的三角形网格上的海冰动力学有限元模型
IF 0.6 4区 数学
Russian Journal of Numerical Analysis and Mathematical Modelling Pub Date : 2023-06-01 DOI: 10.1515/rnam-2023-0012
Sergey S. Petrov, N. Iakovlev
{"title":"SIMUG – finite element model of sea ice dynamics on triangular grid in local Cartesian basis","authors":"Sergey S. Petrov, N. Iakovlev","doi":"10.1515/rnam-2023-0012","DOIUrl":"https://doi.org/10.1515/rnam-2023-0012","url":null,"abstract":"Abstract The paper presents the dynamical core of the new sea ice model SIMUG (Sea Ice Model on Unstructured Grid) on the A- and CD-types of unstructured triangular grids in the local-element basis on sphere. Three standardized box tests to reproduce the Linear Kinematic Features (LKFs), and the short-term forecast in the real Arctic Ocean geometry with the realistic atmosphere and ocean forcing demonstrate the model quality compared to other sea ice models like CICE, FESOM, MITgcm, and ICON-O. The distinctive features of the model presented are a wide choice of transport schemes, and the new numerical implementation with the serial and parallel C++ coding and INMOST, Ani2D, and Ani3D packages to deal with unstructured grids. Code profiling and scalability assessment are carried out. In general, the A-version of the ice drift model works faster, but has fewer degrees of freedom on the same grid. Due to the increase in the degrees of freedom, the model on the CD grid gives ultra-resolution of LKFs, but requires more strict conditions for stability.","PeriodicalId":49585,"journal":{"name":"Russian Journal of Numerical Analysis and Mathematical Modelling","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47707361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信