搜索结果: 76-90 共查到“知识库 计算数学”相关记录1183条 . 查询时间(4.883 秒)
利用离散控制理论, 针对结构动力学方程时间积分提出了一种新的无条件稳定的显式算法. 新算法采用CR 算法的速度和位移递推格式, 同时利用Z变换获得算法对应的传递函数, 进而根据极点条件推导了递推格式系数的具体表达式. 然后, 在其系数中引入了一个控制周期延长率的变量s, 从而调节新算法的精度. 理论分析表明无条件稳定显式新算法具有二阶精度、零振幅衰减率、无超调和自起步特性, 且周期延长率可以用变量...
We show that any global convex solution to the Sigma-2 equation must be quadratic.
On Aleksandrov-Fenchel Inequalities for k-Convex Domains
On Aleksandrov-Fenchel Inequalities k-Convex Domains
2014/4/3
These are the lecture notes based on a course which the first named author has given at the second congress organized by the Riemann International School of Mathematics in Verbania, Italy from S...
ON A CONFORMAL GAP AND FINITENESS THEOREM FOR A CLASS OF FOUR MANIFOLDS
ON A CONFORMAL GAP FINITENESS THEOREM CLASS OF FOUR MANIFOLDS
2014/4/3
In this paper we develop a bubble tree structure for a degenerating class of Riemannian metrics satisfying some global conformal bounds on compact manifolds of dimension 4. Applying the bubble tree st...
In this note we study some conformal invariants of a Riemannanian manifold (Mn;g) equipped with a smooth measure m. In particular, we show that there is a natural de nition of the Ricci and scalar cur...
GLOBAL SOLUTIONS OF THE EULER–MAXWELL TWO-FLUID SYSTEM IN 3D
GLOBAL SOLUTIONS THE EULER–MAXWELL TWO-FLUID SYSTEM 3D
2014/4/3
The fundamental “two-fluid” model for describing plasma dynamics is given by the EulerMaxwell system, in which compressible ion and electron fluids interact with their own self-consistent ...
EQUIVARIANT SCHRODINGER MAPS IN TWO SPATIAL ¨ DIMENSIONS: THE H2 TARGET
EQUIVARIANT SCHRODINGER MAPS TWO SPATIAL DIMENSIONS THE H2 TARGET
2014/4/3
We consider equivariant solutions for the Schr¨odinger map problem from R2+1to H2 with finite energy and show that they are global in time and scatter.
LOCAL FORMULAS FOR THE HYDRODYNAMIC PRESSURE AND APPLICATIONS
LOCAL FORMULAS HYDRODYNAMIC PRESSURE APPLICATIONS
2014/4/3
We provide local formulas for the pressure of incompressible uids. The pressure can be expressed in terms of its average and averages of squares of velocity increments in arbitrary small neighborhoods...
INVISCID MODELS GENERALIZING THE 2D EULER AND THE SURFACE QUASI-GEOSTROPHIC EQUATIONS
INVISCID MODELS GENERALIZING 2D EULER THE SURFACE QUASI-GEOSTROPHIC EQUATIONS
2014/4/3
Any classical solution of the 2D incompressible Euler equation is global in time. However, it remains an outstanding open problem whether classical solutions of the surface quasi-geostrophic (SQG) equ...
Analyticity of Lagrangian trajectories for well posed inviscid incompressible fluid models
Analyticity of Lagrangian trajectories well posed inviscid incompressible fl uid models
2014/4/3
We discuss general incompressible inviscid models, including the Euler equations, the surface quasi-geostrophic equation, incompressible porous medium equation, and Boussinesq equations. All these mod...
求不定二次规划问题全局解的单调化方法
全局优化 不定二次规划 单调优化
2014/7/18
不定二次规划是全局优化的一类重要问题，在金融、统计、工程设计等实际问题中有广泛应用。但此类问题可能存在多个非全局最优的局部极值点，所以求其全局最优解变得十分困难。运用单调优化理论提出一种求不定二次规划问题全局最优解的新方法：通过引入新变量将问题等价转化为单调优化问题，然后利用问题的单调结构进行缩减、分割、辅助问题最优值的定界等过程获得近似全局最优解。该解不仅可行且能充分接近真实的全局最优解，数值结...
基于迭代重赋权最小二乘算法的块稀疏压缩感知
压缩感知 迭代重赋权最小二乘算法 块稀疏信号 误差估计 局部收敛性
2017/1/9
压缩感知是一种新颖的信号处理理论.它突破了传统香农采样理论对采样的限制,以信号的稀疏性或可压缩性为基础,实现了信号的高效获取和精确重构.然而在现实中,部分稀疏信号还表现出一些其他结构,典型的例子就是一类块稀疏信号,其非零元素以块的形式出现.针对这类信号,本文研究了求解块稀疏压缩感知的迭代重赋权最小二乘算法(IRLS),给出了该算法的理论分析:误差估计和局部收敛性分析.大量试验验证了基于迭代重赋权最...
We prove the existence of a compact global attractor for the dynamics of the forced critical surface quasi-geostrophic equation (SQG) and prove that it has finite fractal (box-counting) dimensio...
一种新的面向普通用户的多值属性关联规则可视化挖掘方法
多值属性 概念格 关联规则 可视化挖掘
2017/1/9
针对传统关联规则可视化挖掘方法不利于处理多值属性数据、缺乏展现数据间的频繁模式和关联模式以及效率低下等问题,提出了基于KAF因子和CHF因子的Apriori改进算法进行多值属性关联规则挖掘,实现了一种新的基于概念格的多值属性关联规则可视化方法.运用概念格理论对多值属性数据进行了重新定义和分类,建立了较为完整的挖掘过程参数调整策略,方便用户选择关键属性值进行规则挖掘分析,提高了算法运行速度和挖掘效率...