共查询到20条相似文献,搜索用时 15 毫秒
1.
《Quaestiones Mathematicae》2013,36(1-3):107-128
A new treatment is given of the cylinder-web diagram and associated diagonal sequences in homotopy pair theory. The efficiency of the diagram as a machine for computing homotopy pair groups is enhanced by a result that traces the path of a Toda bracket element through the arrows of the diagram. The diagonal factorization problem for a homotopy pair class is studied and related to the behaviour of Toda brackets. A necessary and sufficient condition for the vanishing of a Toda bracket is obtained. 相似文献
2.
Abel范畴中态射乘积诱导的短正合列及其应用 总被引:8,自引:0,他引:8
本文给出了Abel范畴中态射乘积αβγ诱导的短正合列的立体交换图。其中共有7个3×3平面,30条线。每一条线(两端的零对象省略)都是一个短正合列.这些短正合列用到p-除环上的矩阵,可以导出一系列矩阵秩的恒等式,它不仅推广了域上矩阵秩的结果,还能得到一些新的关系式. 相似文献
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4.
We study the asymptotics of certain measures on partitions (the so-called z-measures and their relatives) in two different regimes: near the diagonal of the corresponding Young diagram and in the intermediate zone between the diagonal and the edge of the Young diagram. We prove that in both cases the limit correlation functions have determinantal form with a correlation kernel which depends on two real parameters. In the first case the correlation kernel is discrete, and it has a simple expression in terms of the gamma functions. In the second case the correlation kernel is continuous and translationally invariant, and it can be written as a ratio of two suitably scaled hyperbolic sines. 相似文献
5.
Lixin Yu 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(4):1073-1087
In this paper, by means of a constructive method based on the existence and uniqueness of the semi-global classical solution, we establish the local exact boundary observability for a kind of second-order quasilinear hyperbolic system in which the number of positive eigenvalues and the number of negative ones are not equal. As an application, we obtain the one-sided local exact boundary observability and two-sided local exact boundary observability with fewer observed values for first-order quasilinear hyperbolic systems of diagonal form with boundary conditions in which the diagonal variables corresponding to the positive eigenvalues and those corresponding to the negative ones are decoupled. 相似文献
6.
R. V. Razumovskiĭ 《Siberian Mathematical Journal》2014,55(4):687-695
7.
Lixin Yu 《Nonlinear Analysis: Theory, Methods & Applications》2010,72(12):4452-1087
In this paper, by means of a constructive method based on the existence and uniqueness of the semi-global C2 solution, we establish the local exact boundary observability for a kind of second order quasilinear hyperbolic systems. As an application, we obtain the one-sided local exact boundary observability for a kind of first order quasilinear hyperbolic systems of diagonal form with boundary conditions in which the diagonal variables corresponding to the positive eigenvalues and those corresponding to the negative eigenvalues are decoupled. 相似文献
8.
The Goeritz matrix of a connected link diagram is diagonalized to a normal form by the elementary divisor theory. The integer sequence given by the diagonal entries of this form is a link invariant called the Georitz invariant. In this paper, we study the Goeritz invariants of pretzel links. 相似文献
9.
Lixin Yu 《Mathematical Methods in the Applied Sciences》2010,33(3):273-286
In this paper, by means of a constructive method based on the existence and uniqueness of the semi‐global C2 solution, we establish the local exact boundary controllability for a kind of second‐order quasilinear hyperbolic systems. As an application, we obtain the one‐sided local exact boundary controllability for the first‐order quasilinear hyperbolic systems of diagonal form with boundary conditions in which the diagonal variables corresponding to the positive eigenvalues and those corresponding to the negative eigenvalues are decoupled. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
10.
Francesca Aicardi 《Functional Analysis and Other Mathematics》2011,3(2):127-133
The exponential of the triangular matrix whose entries in the diagonal at distance n from the principal diagonal are all equal to the sum of the inverses of the divisors of n is the triangular matrix whose entries in the diagonal at distance n from the principal diagonal are all equal to the number of partitions of n. A similar result holds for all pairs of sequences satisfying a special mutual recurrence. 相似文献
11.
For a class of block two-by-two systems of linear equations with certain skew-Hamiltonian coefficient matrices, we construct additive block diagonal preconditioning matrices and discuss the eigen-properties of the corresponding preconditioned matrices. The additive block diagonal preconditioners can be employed to accelerate the convergence rates of Krylov subspace iteration methods such as MINRES and GMRES. Numerical experiments show that MINRES preconditioned by the exact and the inexact additive block diagonal preconditioners are effective, robust and scalable solvers for the block two-by-two linear systems arising from the Galerkin finite-element discretizations of a class of distributed control problems. 相似文献
12.
D. Drinen 《Proceedings of the American Mathematical Society》2000,128(7):1991-2000
Every AF-algebra arises as the -algebra of a locally finite pointed directed graph in the sense of Kumjian, Pask, Raeburn, and Renault. For AF-algebras, the diagonal subalgebra defined by Stratila and Voiculescu is consistent with Kumjian's notion of diagonal, and the groupoid arising from a well-chosen Bratteli diagram for coincides with Kumjian's twist groupoid constructed from a diagonal of .
13.
王新民 《数学的实践与认识》2011,41(6)
研究了矩阵的特征根与特征向量及其相似对角形的优化求法.优化了文[1]的方法,只要对矩阵A的特征矩阵λE-A施行初等变换化为对角形,即可同时求出A的特征根与特征向量,判断A是否可对角化.在A可对角化时,可直接写出相应的可逆矩阵T,使T~(-1)AT为对角形矩阵. 相似文献
14.
DNA序列的特征数值及相似性分析 总被引:1,自引:0,他引:1
白凤兰 《数学的实践与认识》2007,37(18):95-99
利用2维图表示DNA序列,计算与该图对应的距离矩阵,求出距离矩阵的不变量—距离矩阵主对角线以外的次对角线之和的平均值,进而得到了DNA序列的一种特征数值,利用这种新的特征数值,对DNA序列进行相似性比较,得到了与现有的资料符合很好的结果. 相似文献
15.
Within the framework of category theory, Cantor diagrams are introduced as the common structure of the self-reference constructions by Cantor, Russell, Richard, Gödel, Péter, Turing, Kleene, Tarski, according to the so-called Cantor diagonal method. Such diagrams consist not only of diagonal arrows but also of idempotent, identity and shift arrows. Cantor theorem states that no Cantor diagram is commutative. From this theorem, all the constructions above can be systematically retrieved. We do this by grouping them into two main classes: the class based on Cantor diagrams with a numerical shift function and the class based on Cantor diagrams with a Boolean shift function. 相似文献
16.
设K/F是整体函数域的素数l次循环扩张,F是有理函数域F_q(T)上的有限可分扩域.利用函数域的Conner-Hurrelbrink正合六边形与源于短正合列的正合六边形,本文在l整除与不整除基域F的理想类数的情形下,分别研究函数域K理想类群的Sylow l-子群的结构.同时,利用得到的结果,本文给出了基域F的单位为K中元素norm的若干条件. 相似文献
17.
Joanne Dombrowski 《Journal of Mathematical Analysis and Applications》2011,378(1):133-139
This paper uses commutator equations to study the absolute continuity of spectral measures associated with certain subclasses of unbounded self-adjoint Jacobi matrix operators determined by properties of the diagonal and subdiagonal sequences. If the diagonal sequence is the zero sequence, properties of the difference sequence of the subdiagonal determine the choice of a bounded operator for the commutator equation. The structure of the resulting commutator leads to results on absolute continuity. 相似文献
18.
An exact algorithm is presented for solving edge weighted graph partitioning problems. The algorithm is based on a branch and bound method applied to a continuous quadratic programming formulation of the problem. Lower bounds are obtained by decomposing the objective function into convex and concave parts and replacing the concave part by an affine underestimate. It is shown that the best affine underestimate can be expressed in terms of the center and the radius of the smallest sphere containing the feasible set. The concave term is obtained either by a constant diagonal shift associated with the smallest eigenvalue of the objective function Hessian, or by a diagonal shift obtained by solving a semidefinite programming problem. Numerical results show that the proposed algorithm is competitive with state-of-the-art graph partitioning codes. 相似文献
19.
本文利用解析方法以及三角和的性质研究两个不同Gauss和的混合均值的计算问题,并给出一个精确的计算公式.作为我们结果的应用,得到了关于模p的一类对角同余方程解的个数的计算公式,其中p是一个奇素数. 相似文献
20.
张跃辉 《中国科学A辑(英文版)》2002,45(6):741-748
Let A be a quasi-hereditary algebra with a strong exact Borel subalgebra. It is proved that for any standard semisimple subalgebra
T there exists an exact Borel subalgebra B of A such that T is a maximal semisimple subalgebra of B. It is shown that the
maximal length of flags of exact Borel subalgebras of A is the difference of the radium and the rank of Grothendic group of
A plus 2. The number of conjugation-classes of exact Borel subalgebras is 1 if and only if A is basic; the number is 2 if
and only if A is semisimple. For all other cases, this number is 0 or no less than 3. Furthermore, it is shown that all the
exact Borel subalgebras are idempotent-conjugate to each other, that is, for any exact Borel subalgebras B and C of A, there
exists an idempotent e of A, and an invertible element u of A, such that eBe = u-1eCeu. 相似文献