搜索结果: 1-15 共查到“知识库 椭圆型偏微分方程”相关记录117条 . 查询时间(5.571 秒)
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...
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...
利用H增生映射的性质，证明了含有广义（p，q）-Laplacian算子的非线性椭圆系统存在唯一解的结论.证明方法简单且研究结果展示了H增生映射和非线性椭圆系统之间的关系，推广和补充了以往的相关研究工作.
具变号权函数的拟线性椭圆方程组多重解的存在性
拟线性椭圆方程组 变号权函数 非平凡解 Nehari流形
2019/4/17
本文研究了具变号权函数的拟线性椭圆方程组多重解的存在性，通过运用变分法，作者得出问题在一定的条件下至少存在两个非平凡非负解.
水平紧密接触品字形三圆管自然对流换热的数值模拟
自然对流 瑞利数 努塞尔数 数值模拟
2019/4/18
采用Bejan提出的新计算模型，模拟计算水平堆积紧密接触品字形三圆管在空气中自然对流的换热过程。在普朗特数Pr=0.707 0，瑞利数10≤Ra≤106的范围内，得到该结构的稳态温度场和流线场、以及局部和平均努赛尔数随Ra变化的结果。在该结构中，两圆管之间相邻部分的空间会形成旋涡；局部努塞尔数Nuθ的最大值出现在140°附近，且随着Ra的增加而增大。同时，获得该结构的平均努塞尔数Nu随Ra变化的经...
构造小嵌入次数的椭圆曲线参数化族
基于配对的密码 椭圆曲线 配对友好曲线 参数化族
2018/5/18
配对友好椭圆曲线在基于配对的密码系统中起关键作用。这类曲线的构造不仅极大影响实现效率，更关系到系统安全。虽然目前已提出很多构造方法，但几乎都依赖穷尽搜索。该文提出一种构造该类曲线的系统方法，将寻找配对友好曲线问题转化到解方程，从而避免了穷尽搜索，并设计出具体算法。最后，将该算法应用到寻找嵌入次数为5,8,10和12的配对友好曲线中，发现所有类型的椭圆曲线族都可由该方法统一得到，包括完全族、可变判别...
基于多项式约束的三角平动点平面周期轨道设计方法
平面圆型限制性三体问题 平动点 多项式展开法
2019/1/2
平动点是圆型限制性三体问题中的五个平衡解.其中，三角平动点在平面问题中具有“中心×中心”的动力学特性，其附近存在着大量的周期轨道，研究这些周期轨道的构建方法在深空探测中具有理论及工程意义.本文从振动角度分析周期轨道，通过多项式展开法构建出主坐标下周期轨道两个运动方向之间的渐近关系.从新的角度分析了系统的动力学特性和平面周期运动两个方向内在关联以及物理规律.这种多项式形式的关系式，可以作为约束条件用...
ELLIPTIC RECONSTRUCTION AND A POSTERIORI ERROR ESTIMATES FOR PARABOLIC PROBLEMS
A posteriori error estimators fi nite elements semidiscrete parabolic problems
2015/12/11
It is known that the energy technique for a posteriori error analysis
of finite element discretizations of parabolic problems yields suboptimal rates
in the norm L1(0; T;L2
(Ω)): In thi...
AN INTEGRABLE DEFORMATION OF AN ELLIPSE OF SMALL ECCENTRICITY IS AN ELLIPSE
INTEGRABLE DEFORMATION ELLIPSE OF SMALL ECCENTRICITY ELLIPSE
2015/9/25
The classical Birkhoff conjecture says that the only integrable convexdomains are circles and ellipses. In the paper we show that a version of this conjecture is true for small perturbations of ellips...
UNIFORMLY ELLIPTIC OPERATORS ON RIEMANNIAN MANIFOLDS
RIEMANNIAN MANIFOLDS ELLIPTIC OPERATORS
2015/8/26
Given a Riemannian manifold (M, g), we study the solutions of heat
equations associated with second order differential operators in divergence
form that are uniformly elliptic with respect to g . Ty...
Efficient distance computation using best ellipsoid fit
ellipsoid fi t geometric approximation collision detection
2015/8/12
This paper describes a method for estimating the distance between a robot and its surrounding environment using best ellipsoid fit. The method consists of the following two stages. First we approximat...
Obstacle collision detection using best ellipsoid fit
ellipsoid fit geometric approximation collision detection
2015/8/11
This paper describes a method for estimating the distance between a robot and its surrounding environment using best ellipsoid fit. The method consists of the following two stages. First we approximat...
An ellipsoidal approximation to the Hadamard product of ellipsoids
Computational efficiency ellipsoid signal
2015/8/11
This paper introduces a computationally efficient outer approximation to the Hadamard, i.e., element-wise, product of two ellipsoids. This element-wise product corresponds to multiplicative uncertaint...
Discrete Symbol Calculus
sublinear complexity inversion of elliptic operators square root of elliptic operators
2015/7/14
This paper deals with efficient numerical representation and manipulation of differential and integral operators as symbols in phase-space, i.e., functions of space x and frequency ξ. The symbol smoot...
Fast construction of hierarchical matrix representation from matrix–vector multiplication
Fast algorithm Hierarchical matrix construction Randomized singular value decomposition Matrix–vector multiplication Elliptic operator Green’s function
2015/7/14
We develop a hierarchical matrix construction algorithm using matrix–vector multiplications, based on the randomized singular value decomposition of low-rank matrices. The algorithm uses Oelog nT appl...