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1.
为了在并行和向量机上求解对称正定性方程且Ax=b,两组多分裂方法被考虑,中,把Galligain和Ruggiero的两级算术平均方法推广到两级多分裂方法并给出了一些合适的内分裂例子,同时讨论了所引起的两级多分裂方法的收敛性。 相似文献
3.
Gioan showed that the number of cycle reversing classes of totally cyclic orientations of a given graph can be calculated
as an evaluation of the corresponding Tutte polynomial. We note that the concept of cycle reversing classes of orientations
coincides with that of Eulerian-equivalence classes considered by Chen and Stanley, and Kochol. Based on this coincidence,
we give a bijective proof of Gioan’s result. Precisely, the main result of the paper is an algorithmic bijection between the
set of Eulerian-equivalence classes of totally cyclic orientations and the set of spanning trees without internally active
edges.
相似文献
4.
首次引入左边块对称和右边块对称的概念,利用Copula研究了其联合分布函数的特点,并分析了这两种对称特性与其它对称特性的联系.最后,提出几个值得进一步讨论的问题 相似文献
5.
为了统一交换环和约化环的层表示,Lambek引进了Symmetric环.继续symmetric环的研究,定义引入了强symmetric环的概念,研究它的一些扩张性质.证明环R是强symmetric环当且仅当R[x]是强symmetric环当且仅当R[x;x~(-1)]是强symmetric环.也证明对于右Ore环R的经典右商环Q,R是强symmetric环当且仅当Q是强symmetric环. 相似文献
6.
C. M. Reidys 《Advances in Applied Mathematics》2001,27(4):790
We study a class of discrete dynamical systems that consists of the following data: (a) a finite (labeled) graph Y with vertex set {1, …, n}, where each vertex has a binary state, (b) a vertex labeled multi-set of functions (Fi, Y:
2n →
2n)i, and (c) a permutation π Sn. The function Fi, Y updates the binary state of vertex i as a function of the states of vertex i and its Y-neighbors and leaves the states of all other vertices fixed. The permutation π represents a Y-vertex ordering according to which the functions Fi, Y are applied. By composing the functions Fi, Y in the order given by π we obtain the sequential dynamical system (SDS):
In this paper we first establish a sharp, combinatorial upper bound on the number of non-equivalent SDSs for fixed graph Y and multi-set of functions (Fi, Y). Second, we analyze the structure of a certain class of fixed-point-free SDSs. 相似文献
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7.
一般的图中Eulerian定向数的计数是#P-完全问题,但对于某些特殊图中的Eulerian定向数给出精确计数是完全有可能的.通过拆分解构的方法可以找到与一类循环图中Eulerian定向数有关的递推关系,从而给出该数的精确计数.前人的工作在于给出了一些近似估计. 相似文献
8.
Genkai Zhang 《Acta Appl Math》2002,73(1-2):79-94
We give a brief survey on the study of constructions of invariant differential operators on Riemannian symmetric spaces and of combinatorial and analytical properties of their eigenvalues, and pose some open questions. 相似文献
9.
A new numerical scheme for computing balancing coordinate transformations for signature symmetric realizations in linear systems theory is presented. The method is closely related to the Jacobi method for diagonalizing symmetric matrices. Here the minimization of the sum of traces of the Gramians by orthogonal and hyperbolic Jacobi-type rotations is considered. Local quadratic convergence of the algorithm is shown. 相似文献
10.
11.
本文讨论一类对称马氏过程的Girsanov变换,这类Girsanov变换是由该对称马氏过程所联系的狄氏型定义域中的函数来确定的.我们证明了对称马氏过程经变换后还是对称的马氏过程,并且给出经变换后的马氏过程所联系的狄氏型.这些结果将前人的相应结论从有界函数推广到更有应用意义的一类无界函数之上. 相似文献
12.
The main objective of this paper is to study an approximation of symmetric tensors by symmetric orthogonal decomposition. We propose and study an iterative algorithm to determine a symmetric orthogonal approximation and analyze the convergence of the proposed algorithm. Numerical examples are reported to demonstrate the effectiveness of the proposed algorithm. We also apply the proposed algorithm to represent correlated face images. We demonstrate better face image reconstruction results by combining principal components and symmetric orthogonal approximation instead of combining principal components and higher‐order SVD results. 相似文献
13.
We study the construction and properties of positive linear functionals on symmetric spaces of measurable functions which are monotone with respect to submajorization. The construction of such functionals may be lifted to yield the existence of singular traces on certain non-commutative Marcinkiewicz spaces which generalize the notion of Dixmier trace. 相似文献
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15.
Hongxing Rui 《Numerical Methods for Partial Differential Equations》2002,18(5):561-583
We present a mixed covolume method for a system of first order partial differential equations resulting from the mixed formulation of the general self‐adjoint parabolic problem with a variable nondiagonal diffusion tensor. The lowest order Raviart‐Thomas mixed element space on rectangles is used. We prove the first order optimal rate of convergence for approximate pressure as well as for approximate velocity. We also prove the second order superconvergence both for approximate velocity and pressure in certain discrete norms. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 561–583, 2002 相似文献
16.
In this paper, we study the quadratic model updating problems by using symmetric low‐rank correcting, which incorporates the measured model data into the analytical quadratic model to produce an adjusted model that matches the experimental model data, and minimizes the distance between the analytical and updated models. We give a necessary and sufficient condition on the existence of solutions to the symmetric low‐rank correcting problems under some mild conditions, and propose two algorithms for finding approximate solutions to the corresponding optimization problems. The good performance of the two algorithms is illustrated by numerical examples. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
17.
A framework for an efficient low-complexity divide-and-conquer algorithm for computing eigenvalues and eigenvectors of an n × n symmetric band matrix with semibandwidth b n is proposed and its arithmetic complexity analyzed. The distinctive feature of the algorithm—after subdivision of the original problem into p subproblems and their solution—is a separation of the eigenvalue and eigenvector computations in the central synthesis problem. The eigenvalues are computed recursively by representing the corresponding symmetric rank b(p–1) modification of a diagonal matrix as a series of rank-one modifications. Each rank-one modifications problem can be solved using techniques developed for the tridiagonal divide-and-conquer algorithm. Once the eigenvalues are known, the corresponding eigenvectors can be computed efficiently using modified QR factorizations with restricted column pivoting. It is shown that the complexity of the resulting divide-and-conquer algorithm is O (n
2
b
2) (in exact arithmetic).This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献
18.
巧用Lagrange乘数法,将一类多元对称函数的条件最值转化为一元函数的无条件最值,避免了具体求复杂而困难的驻点方程组的解,使问题化难为易. 相似文献
19.
We characterize the best model geometries for the class of virtually free groups, and we show that there is a countable infinity of distinct best model geometries in an appropriate sense – these are the maximally symmetric trees. The first theorem gives several equivalent conditions on a bounded valence, cocompact tree T without valence 1 vertices saying that T is maximally symmetric. The second theorem gives general constructions for maximally symmetric trees, showing for instance that every virtually free group has a maximally symmetric tree for a model geometry. 相似文献