搜索结果: 16-30 共查到“偏微分方程”相关记录1914条 . 查询时间(0.465 秒)
求解偏微分方程的预处理迭代方法是计算数学近四十年的一个热门研究方向， 这一方法得以成功的关键是有效预条件子的构造。有效预条件子的构造和分析是技巧性很强的工作， 尤其是对于具强间断系数的偏微分方程， 比如对此情形多层网格预条件子和重叠区域分解预条件子的最优收敛性在理论上一直没有彻底弄清楚。在2007年R. Hiptmair和J. Xu对麦克斯韦方程提出了“辅助空间预条件子”， 这种预条件子曾引起国际...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：The Cerednik--Drinfeld uniformization theorem
Cerednik-Drinfeld 一致化定理 Drinfeld半平面 Shimura曲线
2023/11/13
In this talk we relate the Drinfeld half plane studiedso far in the seminar with certain Shimura curves.which are of more global arithmetic interest. Therelation is expressed in a certain uniformizati...
非自伴Dirac算子的椭圆有限带位势
非自伴 Dirac算子 椭圆 有限带位势
2023/12/13
We present an explicit two-parameter family of finite-band Jacobi elliptic potentials given by $q\equiv A\dn(x;m)$, where $m\in(0,1)$ and $A$ can be taken to be positive without loss of generality, fo...
对称椭圆特征值问题的一个局部化的最优预处理Newton-Schur方法
对称椭圆 特征值问题 局部化 最优预处理 Newton-Schur
2023/12/13
A locally optimal preconditioned Newton-Schur method is proposed for solving symmetric elliptic eigenvalue problems. Firstly, the Steklov-Poincaré operator is used to project the eigenvalue problem on...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Mixing flow and advection-diffusion-reaction equations
混合流 平流 扩散反应方程
2023/5/18
In the study of incompressible fluid, one fundamental phenomenon that arises in a wide variety of application is dissipation enhancement by so-called mixing flow. In this talk, I will give a brief int...
成都信息工程大学应用数学学院周钰谦教授
成都信息工程大学应用数学学院 周钰谦 教授 偏微分方程 孤立子理论 微分动力系统
2023/12/4
周钰谦，男，教授，1979年1月生，中共党员。2004年毕业于四川师范大学数学与软件科学学院运筹学与控制论专业，获理学硕士学位。2008年毕业于四川大学数学院应用数学专业，获理学博士学位。2011年云南大学博士后流动站出站。现任应用数学学院院长。长期从事偏微分方程、孤立子理论、微分动力系统方向的研究。在不可积系统行波解的分岔以及带有奇线的可积系统行波解的分岔等方面取得了一系列创新性成果。现已在《N...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：No blow-up by nonlinear It? noise for the Euler equations
非线性 爆炸 欧拉方程 噪声
2023/5/17
We consider the incompressible Euler equations in two or three dimensions and we show that the addition of a suitable multiplicative It? noise with superlinear growth prevents a smooth solution from b...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Solitons and Breathers in the modulus KdV equations
模量 KdV方程 孤子 呼吸器
2023/5/12
Compared to the soliton solutions, the breathers, which are constructed in the mKdV or Gardner equation via integrability methods, are less studied. In our numerical study, we show the interactions be...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Numerical PDEs for Fluid-Structure Interaction (FSI) Problems
流固耦合 数值 偏微分方程
2023/5/8
The interaction of a flexible structure with a flowing fluid in which it is submersed or by which it is surrounded gives rise to a rich variety of physical phenomena with applications in many fields o...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Machine learning methods for forward and inverse PDEs
正反向 偏微分方程 机器学习
2023/4/27
本报告介绍我们近期的两项工作。(1) 求解PDE的PINN方法在处理时间发展方程时往往遇到难以收敛的困难。我们发展了时间方向的预训练PINN方法及自适应步长方法，解决了收敛性困难，使PDE求解精度能够得到系统性提高。我们在一系列时间发展方程上获得了比文献报道更精确的训练结果。(2) 辐射调源问题是一个典型的反问题，要求调整辐射输运方程的边条件(源)，使解满足特定设计目标。我们针对辐射输运方程的时序...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Conformally variational Riemannian invariants and their related topics
共形变分 黎曼不变量 主题
2023/4/23
It is well known that scalar curvature plays a fundamental role in general relativity. As its analogue, conformally variational Riemannian invariants (CVIs) is a category of fundamental scalar-type cu...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Structured Matrices Approach for Legendre Pairs
勒让德对 结构化 矩阵方法
2023/4/17
Legendre Pairs are combinatorial objects with a rich 20+ years history. Their main application is that they furnish a structured form of the Hadamard conjecture and they have been studied by several a...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Some recent progress on the gradient estimates for the insulated conductivity problem
绝缘 电导率 梯度估计 椭圆偏微分方程
2023/4/17
In this talk, I will describe an elliptic PDE that models electric conduction, and the electric field concentration phenomenon between closely spaced inclusions of high contrast. In the first part, I ...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Calogero-Moser空间的辛全形稠密性
Calogero-Moser空间 辛全形 稠密性
2023/4/13
和在复几何有不少应用的稠密性相比，目前没有很多辛稠密的Stein流形。探讨稠密性在辛范畴的推广，需要足够例子。第一个例子是偶维复欧式空间，Forstneric证明了辛切变生成它的辛自构群的一个稠密子群。在这个报告我会介绍稠密概念的来源，辛稠密的定义和特征，以及作为其推论的辛版Andersen-Lempert定理（在紧致集上用辛自构映射模拟向量场的局部相流）。最后介绍Calogero-Moser空间...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Pseudorandomness of Sato-Tate Distributions for Elliptic Curves
椭圆曲线 佐藤-泰特分布 伪随机性
2023/4/13
Equidistribution is an important theme in number theory. The Sato-Tate conjecture, which was established by Richard Taylor et.al. in 2008, asserts that given an elliptic curve over Q without complex m...