首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 46 毫秒
1.
对分片 C2凸函数的 Moreau-Yosida逼近研究了它的梯度性质,引进了序列常秩约束条件,在此条件下证明了梯度函数具有分片光滑性质.  相似文献   

2.
本文对二阶拟线性严格双曲方程,得出了具有弱间断的分片光滑行波的传播和干扰的结果.为此还在最为一般的情形,证明了拟线性Cauchy问题局部解的存在性与唯一性.  相似文献   

3.
在实际应用中,有一些信号是具有分片的结构的.本文我们提出一种分片正交匹配追踪算法(P\_OMP)来求解分片稀疏恢复问题,旨在保护分片信号中的分片结构(或者小尺度非零元).P\_OMP算法是基于CoSaMP和OMMP算法的思想上延伸出的一种针对分片稀疏问题的贪婪算法. P\_OMP算法不仅仅具有OMP算法的优势,还能够在比CoSaMP方法更松弛的条件下得到同样的误差下降速率.进一步,P\_OMP~算法在保护分片稀疏信号的尺度细节信息上表现的更好.数值实验表明相比于CoSaMP, OMP, OMMP和BP算法, P\_OMP算法在分片稀疏恢复上更有效更稳定.  相似文献   

4.
分片代数曲线是经典代数曲线的推广. 贯穿剖分上的分片代数曲线的Nöther型定理对构造二元样条空间的Lagrange插值适定结点组有非常重要的作用. 文中利用二元样条的性质, 给出了任意三角剖分上分片代数曲线的Nöther型定理.  相似文献   

5.
方燕 《工科数学》1999,15(1):9-16
本文利用撮动的思想,以摄动有理曲线(曲面)的系数的无穷模怍为优化目标,给出了用多项式曲线(曲面)逼近有理曲线(曲面)的一种新方法.同以前的各种方法相比,该方法不仅收敛而且具有更快的收敛速度,并且可以与细分技术相结合.得到有理曲线与曲面的整体光滑,分片多项式的逼近。  相似文献   

6.
分片代数曲线是经典代数曲线的推广.贯穿剖分上的分片代数曲线的Nther型定理对构造二元样条空间的Lagrange插值适定结点组有非常重要的作用.文中利用二元样条的性质,给出了任意三角剖分上分片代数曲线的N(?)ther型定理.  相似文献   

7.
基于四叉树的思想,提出了一种图像分片融合算法,通过求解若干建立在梯度域上的低维泊松方程组,实现了图像无缝融合.相比较传统的泊松算法,这种分片处理策略,一方面大大降低了大幅宽图像融合对计算机内存和计算性能的要求,为普通计算机处理大幅宽图像融合提供了新的途径,同时也能支持并行处理,从而提升大幅宽图像融合效率.算法保证了融合图像整体上分片连续,有效去除了接缝,适用于超高分辨率或航拍等大幅宽图像拼接问题.  相似文献   

8.
本文对确定分片代数曲线的二元样条函数的整体表达式中的截断引入参数表示,给出了分片代数曲线交点的结式求法.理论与实例表明,这种算法是有效的.  相似文献   

9.
拟贯穿剖分上分片代数曲线的Nother型定理   总被引:1,自引:0,他引:1  
代数曲线的Nother定理是代数几何中经典并且十分重要的结论.作为二元样条的零点集,分片代数曲线是经典代数曲线的推广.分片代数曲线的Nother型定理对研究二元样条空间的Lagrange插值有至关重要的作用.利用拟贯穿剖分的特点、二元样条的性质与代数几何的相关知识,给出了拟贯穿剖分上分片代数曲线的Nother型定理.  相似文献   

10.
分片代数曲线作为二元样条函数的零点集合是经典代数曲线的推广. 利用代数的基本知识, 本文对实分片代数曲线的基本性质进行了初步讨论, 并且将实分片代数曲线与相应的二元样条分类进行讨论. 最后, 对实分片代数曲线上的孤立点进行了研究.  相似文献   

11.
In this paper we provide a Liouville type theorem in the framework of fracture mechanics, and more precisely in the theory of SBV deformations for cracked bodies. We prove the following rigidity result: if uSBV(Ω,RN) is a deformation of Ω whose associated crack Ju has finite energy in the sense of Griffith's theory (i.e., HN−1(Ju)<∞), and whose approximate gradient ∇u is almost everywhere a rotation, then u is a collection of an at most countable family of rigid motions. In other words, the cracked body does not store elastic energy if and only if all its connected components are deformed through rigid motions. In particular, global rigidity can fail only if the crack disconnects the body.  相似文献   

12.
13.
A piecewise convex program is a convex program such that the constraint set can be decomposed in a finite number of closed convex sets, called the cells of the decomposition, and such that on each of these cells the objective function can be described by a continuously differentiable convex function.In a first part, a cutting hyperplane method is proposed, which successively considers the various cells of the decomposition, checks whether the cell contains an optimal solution to the problem, and, if not, imposes a convexity cut which rejects the whole cell from the feasibility region. This elimination, which is basically a dual decomposition method but with an efficient use of the specific structure of the problem is shown to be finitely convergent.The second part of this paper is devoted to the study of some special cases of piecewise convex program and in particular the piecewise quadratic program having a polyhedral constraint set. Such a program arises naturally in stochastic quadratic programming with recourse, which is the subject of the last section.This paper is based on the author's Ph.D. Dissertation presented at the Faculté des Sciences Appliquées of the Université Catholique de Louvain. It describes research supported partly by the Programme National d'Impulsion à la Recherche en Informatique of the Belgian Government under contract No. I (14 bis) 6 and partly by a two-year fellowship of the Centre Interuniversitaire d'Etudes Doctorales dans les Sciences du Management.  相似文献   

14.
15.
Let G be a finitely generated module over a PID, D. We investigate the structure of the centralizer near-ring MD(G) = {f: G → G ¦ f(ar) = (fa)r,a ∈ G, r ∈ D}. If C = {Gα} is a cover of G by maximal cyclic submodules then we show that every f ∈ MD(G) is piecewise an endomorphism of G.  相似文献   

16.
For best piecewise polynomial approximation n=n (f; [0, 1]) of a functionf, which is continuous on the interval [0, 1] and admits a bounded analytic continuation onto the disk K=z:¦z–1¦<, the relation n=o[ f (e n )] is valid.Translated from Matematicheskie Zametki, Vol. 11, No. 2, pp. 129–134, February, 1972.  相似文献   

17.
In reaction to a recent paper by E. Passow in this Journal, it is shown that broken line interpolation as a scheme for piecewise monotone interpolation is hard to improve upon. It is also shown that a family of smooth piecewise polynomial interpolants, introduced by Swartz and Varga and noted by Passow to be piecewise monotone, converges monotonely, for fixed data, to a piecewise constant interpolant as the degree goes to infinity. Finally, piecewise monotone interpolation by splines with simple knots is discussed.  相似文献   

18.
A spread $\cal S$ of the real projective 3-space PG(3,?) is called piecewise regular, if, roughly speaking, the Klein image of $\cal S$ is composed of two elliptic caps and z elliptic zones (z ∈ {0,1,2,…}); we say that $\cal S$ is of segment number z + 2. We use piecewise regular spreads in order to give explicit examples of rigid and hyperrigid spreads. A spread $\cal T$ of a projective 3-space II is called rigid, if the only collineation of II leaving $\cal T$ invariant is the identity. A rigid spread ? is said to be hyperrigid, if there is no duality of II leaving ? invariant. We exhibit a 3-parameter family S″ of rigid piecewise regular spreads of segment number 4 and show that S″ contains spreads which represent non-isomorphic rigid 4-dimensional translation planes. Finally, we construct a 7-parameter family H of explicit examples of hyperrigid piecewise regular spreads of segment number 5. In H there are at least four spreads which represent mutually non-isomorphic rigid 4-dimensional translation planes.  相似文献   

19.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号