检索结果-内蒙古大学图书馆

Shape optimization of concrete free-form shells considering material damage

ENGINEERING OPTIMIZATION 2022年第12期54卷 1981-1998页

作者： San, Bingbing Feng, Dongming Qiu, Ye Hohai Univ Coll Civil & Transportat Engn Nanjing Peoples R China Southeast Univ Key Lab Concrete & Prestressed Concrete Struct Nanjing Peoples R China

Shape optimization is a pervasive tool for designing concrete free-form shells. However, the existing shape optimization approaches for free-form shells usually assume the material is purely elastic without considering material damage, which may produce undesired results in real-world structural applications, especially in the case of concrete structures. In this article, a framework is presented for performing the shape optimization of concrete free-form shells while considering concrete damage. In the proposed optimization algorithm, the Mazars model is coupled with finite element analysis for modelling structural responses subjected to material damage. Through a series of numerical examples, the proposed algorithm is validated and the effects of material damage on optimal results are investigated. It is demonstrated that the consideration of material damage leads to a more robust design, which highlights the importance of accounting for the material damage during the shape optimization process of concrete free-form shells.

关键词： Free-form shells shape optimization concrete damage numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

Real-Time Torque Control of IPMSM Under Flux Variations

引用

IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS 2022年第3期10卷 3345-3356页

作者： Kim, Hyeon-Sik Sul, Seung-Ki Gachon Univ Dept Elect Engn Seongnam 13120 South Korea Seoul Natl Univ Dept Elect & Comp Engn Seoul 08826 South Korea

For interior permanent magnet synchronous motor (IPMSM) drives, accurate torque control and loss-minimizing operation are essential issues to keep up the excellent features of IPMSM. However, flux linkage variations owing to various operating conditions make it challenging to maintain their efficiency at the highest level during overall operating conditions. In this article, a real-time torque control is proposed to satisfy both torque control accuracy and high-efficiency operation in consideration of flux linkage variations. First, torque control under the minimum copper loss is modeled as a constrained optimization problem to satisfy both torque reference tracking and loss-minimizing operation in both maximum torque per ampere (MTPA) and flux-weakening regions. Current references are calculated through robust numerical and region identification algorithms in a command optimizer. Moreover, both stator flux linkages and dynamic inductances are estimated to reflect the flux variations in real time, which are the parts of a parameter estimator. The proposed estimators are designed to extract the fundamental flux linkages and their variations while maintaining high dynamic performance. The performance of the proposed methods is verified by the simulation and experimental results where premade lookup tables are not utilized at all.

关键词： Couplings Torque control Torque Mathematical model Real-time systems Heuristic algorithms Vehicle dynamics Command optimizer dynamic inductance estimator flux linkage variations flux observer interior permanent magnet synchronous motor (IPMSM) minimum copper-loss operation numerical algorithm torque control

来源：评论

学校读者我要写书评

暂无评论

Reaching Takahashi-type nonexpansive operators via modular structures with application to best proximity point

引用

ADVANCES IN OPERATOR THEORY 2023年第2期8卷 1-29页

作者： Usurelu, Gabriela Ioana Bejenaru, Andreea Postolache, Mihai Univ Politeh Bucharest Dept Math & Informat Bucharest 060042 Romania North Minzu Univ Key Lab Intelligent Informat & Big Data Proc NingX Yinchuan 750021 Peoples R China North Minzu Univ Hlth Big Data Res Inst Yinchuan 750021 Peoples R China Romanian Acad Gheorghe Mihoc Caius Iacob Inst Math Stat & Appl M Bucharest 050711 Romania

In this study, we introduce the concepts of modular Reich-type and modular Chatterjea-type nonexpansive mappings, as natural extensions of their definitions from normed vector spaces to modular vector spaces. After describing the two modular conditions and emphasize their role through some examples, we use them in connection with an iteration procedure for obtaining some fixed point convergence-related conclusions. In addition, a connection between modular Chatterjea-type nonexpansive mappings and Takahashi hybrid operators is analyzed. As a remarkable application, we incorporate modular Reich-type and modular Chatterjea-type nonexpansive mappings together with the iteration process into a modular proximal setting and state some best proximity point results.

关键词： Reich mappings Chatterjea mappings Modular vector space Fixed point Best proximity point numerical algorithm Iteration

来源：评论

学校读者我要写书评

暂无评论

High order algorithms for numerical solution of fractional differential equations

引用

ADVANCES IN DIFFERENCE EQUATIONS 2021年第1期2021卷 1-23页

作者： Asl, Mohammad Shahbazi Javidi, Mohammad Yan, Yubin Univ Tabriz Dept Math Tabriz Iran Univ Chester Dept Math Chester CH1 4BJ Cheshire England

In this paper, two novel high order numerical algorithms are proposed for solving fractional differential equations where the fractional derivative is considered in the Caputo sense. The total domain is discretized into a set of small subdomains and then the unknown functions are approximated using the piecewise Lagrange interpolation polynomial of degree three and degree four. The detailed error analysis is presented, and it is analytically proven that the proposed algorithms are of orders 4 and 5. The stability of the algorithms is rigorously established and the stability region is also achieved. numerical examples are provided to check the theoretical results and illustrate the efficiency and applicability of the novel algorithms.

关键词： numerical algorithm Fractional differential equation Caputo fractional derivative Stability analysis Error estimates 26A33 65D05 65D30

来源：评论

学校读者我要写书评

暂无评论

Multipole Expansion of the Fundamental Solution of a Fractional Degree of the Laplace Operator

引用

Journal of Mathematical Sciences (United States) 2023年第5期275卷 548-555页

作者： Belevtsov, N.S. Lukashchuk, S. Yu. Ufa State Aviation Technical University Ufa Russian Federation

A multipole expansion of the fundamental solution of the fractional power of the Laplace operator is constructed in terms of the Gegenbauer polynomials. Based on the decomposition constructed and the idea of the fast multipole method, we propose a numerical algorithm for solving the fractional differential generalization of the Poisson equation in the two-dimensional and three-dimensional spaces. © 2023, Springer Nature Switzerland AG.

关键词： 35J08 35J08 35R11 35R11 fast multipole method fractional Laplacian fundamental solution multipole expansion numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

A Constructive Approach About the Existence of Positive Solutions for Minkowski Curvature Problems (vol 45, pg 1, 2021)

引用

BULLETIN OF THE MALAYSIAN MATHEMATICAL SCIENCES SOCIETY 2022年第1期45卷 17-18页

作者： Yang, Rui Lee, Jong Kyu Lee, Yong-Hoon Cent South Univ Sch Math & Stat Changsha 410083 Hunan Peoples R China Pusan Natl Univ Dept Math Busan 46241 South Korea

In this paper, we give an existence theorem about positive solutions for the Dirichlet boundary value problem of one dimensional Minkowski curvature equations. We apply the theorem to one parameter family of problems to investigate a constructive method for numerical range of parameters where positive solutions exist. Moreover, we establish a nonexistence theorem of positive solutions for the corresponding one parameter family of problems. The coefficient function may be singular at the boundary and nonlinear term satisfies a sublinear growth condition. Main argument for the proof of existence theorem is employed by Krasnoselskii’s theorem of cone expansion and compression. We give a numerical algorithm and various examples to illustrate numerical information about ranges of the existence and nonexistence parameters which have been given only in a theoretical manner so far.

关键词： Existence Minkowski curvature equation Nonexistence numerical algorithm Positive solution Singular coefficient function

来源：评论

学校读者我要写书评

暂无评论

Uniqueness of system integration scheme of artificial intelligence technology in fractional differential mathematical equation

引用

APPLIED MATHEMATICS AND NONLINEAR SCIENCES 2022年第1期8卷 1167-1176页

作者： Chen, Xuming Zhu, Jianfa Li, Liangxiao Long, Chengwen Jiangxi Coll Appl Technol Ganzhou 341000 Jiangxi Peoples R China

In order to explore the fractional differential equations in accounting informatization financial software, the author proposes a system for fractional diffusion wave equations and fractional differential equations, two numerical algorithms with higher precision are given, and the amount of computation is reduced at the same time. First, based on the equivalent integral form of the time fractional diffusion wave equation, using the fractional echelon method and the Crank-Nicolson method, for the time fractional diffusion wave equation, a finite difference scheme is designed, this format has second-order accuracy in both the temporal and spatial directions and is computationally stable. numerical examples verify the accuracy and effectiveness of this format. Then when dealing with the initial value problem of fractional differential equations with Caputo derivative operator, convert it to the equivalent Voltera integral equation system, an initial approximate solution is obtained by a low-order method, derive the residual and error equations, the idea of applying the stepwise correction of spectral delay correction improves the numerical accuracy of the solution, at the same time, the Richard Askey integral equation is used to reduce the amount of calculation. At last, the high precision and effectiveness of the new method are verified by numerical experiments. Experiments show that: Starting from the equivalent integral form of the fractional diffusion wave equation, a second-order finite-difference scheme of the fractional-order diffusive wave equation is constructed, through numerical experiments, it is verified that the scheme has good accuracy and efficiency. In numerical solution, discrete integral equations have better numerical stability than differential equations, therefore, the format also has better stability. When taking different fractional derivative indices a=1.5 and a=1.8, it can be seen that the difference format constructed by the author, in the ti

关键词： Accounting informatization Financial software Fractional order Differential equation numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

The Coupled Model for Surface Modification of Titanium Nickelide

引用

LOBACHEVSKII JOURNAL OF MATHEMATICS 2023年第6期44卷 2317-2325页

作者： Kryukova, O. N. Knyazeva, A. G. Russian Acad Sci Siberian Branch Inst Strength Phys & Mat Sci Tomsk 634055 Russia

In this paper, a coupled model of coating modification placed on a substrate is proposed. The model takes into account the different channels of stress effect on the evolution of coating and transition zone composition. The coupled model of coated material modification by pulsed electron beam is formulated for the first time, with particular attention paid to the mutual influence of stresses arising from composition changes and diffusion transport. Examples of calculations for the Ta-TiN system are presented which demonstrate both qualitative and quantitative differences between coupled and uncoupled problems.

关键词： coupled model reaction rates residual stresses numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

AN EFFICIENT algorithm FOR SOLVING ELLIPTIC PROBLEMS ON PERCOLATION CLUSTERS

引用

ANNALS OF APPLIED PROBABILITY 2022年第4期32卷 2755-2810页

作者： Gu, Chenlin PSL Univ Ecole Normale Super DMA Paris France

We present an efficient algorithm to solve elliptic Dirichlet problems defined on the cluster of supercritical Z(d)-Bernoulli percolation, as a generalization of the iterative method proposed by S. Armstrong, A. Hannukainen, T. Kuusi and J.-C. Mourrat (ESAIM Math. Model. Numer. Anal. (2021) 55 37-55). We also explore the two-scale expansion on the infinite cluster of percolation, and use it to give a rigorous analysis of the algorithm.

关键词： numerical algorithm stochastic homogenization percolation

来源：评论

学校读者我要写书评

暂无评论

Evaluation of the numerical algorithms of the plasma dispersion function

引用

JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2019年 234卷 64-70页

作者： Wang, Sicheng Huang, Sixun Natl Univ Def Technol Inst Meteorol & Oceanog Nanjing Jiangsu Peoples R China State Ocean Adm Inst Oceanog 2 State Key Lab Satellite Ocean Environm Dynam Hangzhou Zhejiang Peoples R China

Plasma dispersion function is an important parameter in the ionospheric physics, fast and accurate computation of this function is extremely valuable in practical use. Many numerical algorithms have been proposed, and it is very necessary to evaluate their performances. In present paper, we first introduce an alternative method to derive the plasma dispersion function and its first derivative using the differential and integral calculus method, and then compare the accuracy and efficiency of three well-known numerical algorithms (algorithm of Steven G. Johnson, algorithm 916, and algorithm of Abrarov and Quine) in Matlab environment under the uniform and non-uniform distribution of the grid-points, and finally analyze the variations of the real and imaginary part of the plasma dispersion function and its first derivative preliminarily. The results show that Abrarov and Quine's algorithm performs better than other two numerical algorithms from the comprehensive viewpoint of accuracy and efficiency. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Plasma dispersion function Differential and integral calculus method numerical algorithm Performance evaluation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：