一类Smale空间上的C~*-代数自同构的熵

Ian Putnam利用Smale空间上的渐近等价关系定义了广群C~*-代数及其典则自同构.本文在零维Smale空间的情形下,计算此类C~*-自同构的逼近熵,证明了相应C~*-动力系统关于CNT熵和逼近熵的"变分原理"成立.由此推演出此类Smale空间上的Bowen测度诱导的C~*-代数上的态是此典则自同构的唯一平衡态.     

构造正交向量的一个新方法及其应用

利用向量的数量积及行列式的按行(列)展开定理,构造出一个n维向量,它能够与n-1个n维向量都正交.这种构造正交向量的方法简单明了.应用这种方法很容易证明克莱姆法则.对这种构造方法加以改进,给出了线性空间Rn中扩充一组正交基的新方法.     

反对称张量空间中可合元素的一些性质

<正> 本文讨论反对称张量空间可合元素的必要条件,用可合元素的 Plücker坐标表示相应子空间的方法以及子空间正交与可合元素之间的关系.设 V 是一个特征为 0 的域 R 上的 n 维向量空间.对于1≤m≤n,(?)V 是 m 阶     

关于张量最小长度的一些结果

本文根据不同重数张量空间之间的关系,采用对张量空间分划的方法,得到了张量空间中张量达到最小长度的一个充分条件和一个必要条件.此外,本文还讨论了最小长度的上界K_max,得到了如下估计:对n维向量空间上的m阶张量空间,n^[m/2]≤K_max≤n^m-1。     

偶特征正交空间中子空间包含关系的条件及矩阵表示

本文研究了特征为2的有限域上正交空间中子空间的包含关系和子空间的矩阵表示,利用了偶特征正交几何的理论,得到了偶特征正交空间中子空间的包含条件和矩阵表示.     

由点矩阵的表示生成的分形矩阵的维数

本文利用n阶整数元方阵作为表示基,以Z~n上的有限个点矩阵作为表示系数,构造了空间R~n中的点矩阵的加法表示系统和乘法表示系统,并分别给出了这两种表示系统导出的分形矩阵在不满足开集条件下的Hausdorff维数的上下界.     

广义多变量平均算子及其组合算子的几乎处处收敛速度（英文）

本文给出了广义多变量平均算子及其组合算子在欧氏空间■~n上Sobolev型空间的几乎处处收敛速度并得到了收敛的饱和度.作为应用,利用转移定理将相关结果推广到了n维环面T~n上.     

张量空间中厄米特算子的一种充要条件

设 L(V)表示 n 维酉空间 V 上的所有线性算子,V 为定义了诱导内积(x~,y~)=(x_i,y_i)的 k 阶张量积空间,其中 x~=x_1…x_k,y~=y_1…y_k 为V 上的可合张量,对于∈L(V),定义W~⊥={(x~,x~)|x_1,…,x_k,o.n.}.本文得到如下结果:(1)设 A_i,B_i∈L(V),i=1,…,k,k相似文献   

偶特征有限正交空间中的几个计数公式及应用

设Fq(n)是Fq上的n维正交空间,设P是任一个给定的m维全奇异子空间.计算了F(qn)中满足dim(P∩Q)=i的r维全奇异子空间Q的个数,给出了用子空间构作认证码的例子.     

不动点集为m1∪i=1RPi(4n)∪m2∪i=1HP1(n)的带有对合的光滑流形

设(Mr,T)是一个在r维光滑闭流形M上的不平凡光滑对合,它的不动点集为F.本文给出了F=m1∪i=1 RRi(4n)∪m2∪i=1HPi(n)(4n＜r)时对合的协边类,其中RP(4n),HP(n)分别表示4n维实射影空间和n维四元数射影空间.     

泛系方法论与幻方构造

论述了泛系方法论的精缩影模式及其对求解、建模、算法生成与理论建构的作用,同时用泛系方法提出并证明了:1递归构造n阶幻方(n≥5)的方法;2已知m阶幻方和n阶幻方(m,n≥3),求mn阶幻方的公式;3已知m阶幻方(m≥3),构造2m阶幻方的方法。     

Space tensor conic programming

Space tensors appear in physics and mechanics. Mathematically, they are tensors in the three-dimensional Euclidean space. In the research area of diffusion magnetic resonance imaging, convex optimization problems are formed where higher order positive semi-definite space tensors are involved. In this short paper, we investigate these problems from the viewpoint of conic linear programming (CLP). We characterize the dual cone of the positive semi-definite space tensor cone, and study the CLP formulation and the duality of positive semi-definite space tensor conic programming.     

Local Tensor Valuations

The local Minkowski tensors are valuations on the space of convex bodies in Euclidean space with values in a space of tensor measures. They generalize at the same time the intrinsic volumes, the curvature measures and the isometry covariant Minkowski tensors that were introduced by McMullen and characterized by Alesker. In analogy to the characterization theorems of Hadwiger and Alesker, we give here a complete classification of all locally defined tensor measures on convex bodies that share with the local Minkowski tensors the basic geometric properties of isometry covariance and weak continuity.     

四边简支正交异性板双向压屈模态的确定及其临界载荷的显式表达式

Libove曾经证明[1],四边简支的正交异性板在双向压力下的屈曲模态沿x方向和y方向的半波数m和n这两者中必有一者为1.本文将给出m=1或n=1的条件,并确定n=1时m的取值,及m=1时n的取值.从而完全确定了四边简支正交异性板在双向压力下的屈曲模态,并给出了临界载荷的显式表达式.     

对称张量的分解和它的应用

本文把任一对称张量分解成两个张量的和,其中之一是“应力型”张量,另一个是“应变型”张量.对称张量空间被分解成两个直交子空间的直和.并用几何语言证明了弹性力学的几个基本原理.     

Differentiation of tensor functions of the state of a body with regard for rotation

We consider the general representation of a tensor function of the state of anisotropic materials in the Euclidean space when the parameters of anisotropy are variable tensors of an arbitrary rank. Based on the generalizations of orthogonal and antisymmetric tensors of higher ranks, we write the equation of the tensor structure of a rotational function of arbitrary rank and the rule for its differentiation in direct (componentless) form. These relations can be used in the problems of the nonlinear mechanics of deformable solids concerning the influence of residual stresses on disturbances of an arbitrary nature in an anisotropic deformable solid. Translated from Matematychni Metody ta Fizyko-Mekhanichni Polya, Vol. 51, No. 1, pp. 99–104, January–March, 2008.     

奇异摄动边值问题的渐近展开

本文研究了奇异摄动边值问题:εy"=f(t,y,ε),y(0)=ξ(ε),y(1)=η(ε),其中ε是一个正小参数.在条件f_y(0,y,0)≥m₀(>0),f_y(1,y,0)≥m₀和f_y(t,y,ε)≥0之下.我们证明了解的存在唯一性,并给出了解的一致有效渐近展开式,从而改进了已有的结果.     

On some problems of tensor calculus. II

Basic definitions of linear algebra and functional analysis are given. In particular, the definitions of a semigroup, group, ring, field, module, and linear space are given [1–3, 6]. A local theorem on the existence of homeomorphisms is stated. Definitions of the inner r-product, local inner product of tensors whose rank is not less than r, and of local norm of a tensor [22] are also given. Definitions are given and basic theorems and propositions are stated and proved concerning the linear dependence and independence of a system of tensors of any rank. Moreover, definitions and proofs of some theorems connected with orthogonal and biorthonormal tensor systems are given. The definition of a multiplicative basis (multibasis) is given and ways of construction bases of modules using bases of modules of smaller dimensions. In this connection, several theorems are stated and proved. Tensor modules of even orders and problems on finding eigenvalues and eigentensors of any even rank are studied in more detail than in [22]. Canonical representations of a tensor of any even rank are given. It is worth while to note that it was studied by the Soviet scientist I. N. Vekua, and an analogous problem for the elasticity modulus tensor was considered by the Polish scientist Ya. Rikhlevskii in 1983–1984.     

Factorization strategies for third-order tensors

Operations with tensors, or multiway arrays, have become increasingly prevalent in recent years. Traditionally, tensors are represented or decomposed as a sum of rank-1 outer products using either the CANDECOMP/PARAFAC (CP) or the Tucker models, or some variation thereof. Such decompositions are motivated by specific applications where the goal is to find an approximate such representation for a given multiway array. The specifics of the approximate representation (such as how many terms to use in the sum, orthogonality constraints, etc.) depend on the application.In this paper, we explore an alternate representation of tensors which shows promise with respect to the tensor approximation problem. Reminiscent of matrix factorizations, we present a new factorization of a tensor as a product of tensors. To derive the new factorization, we define a closed multiplication operation between tensors. A major motivation for considering this new type of tensor multiplication is to devise new types of factorizations for tensors which can then be used in applications.Specifically, this new multiplication allows us to introduce concepts such as tensor transpose, inverse, and identity, which lead to the notion of an orthogonal tensor. The multiplication also gives rise to a linear operator, and the null space of the resulting operator is identified. We extend the concept of outer products of vectors to outer products of matrices. All derivations are presented for third-order tensors. However, they can be easily extended to the order-p(p>3) case. We conclude with an application in image deblurring.