弱P-反演半群上的P-核正规系

In this paper,we first give the concept of weakly P-inversive semigroup S(P).Then we describe the strong P-congruences on S(P)in terms of their P-kernel normal systems.It is proved that there is a bijection between the strong P-congruences and the P-kernel normal systems.Finally,it is also prove that the lattice of strong P-congruences and the lattice of P-kernel normal systems on S(P)are isomorphic.     

弱Y-反演半群上的模糊Y-核正规系

借助于模糊Y-核正规系刻画了弱Y-反演半群S（P）上的强Y-同余。证明了S（P）上的每一个模糊强Y-同余都是由它的模糊Y-核正规系所唯一决定的。     

广义弱亚正规算子的正规性

主要研究了T是广义弱亚正规算子时,T~t是拟正规算子的充要条件是T是拟正规算子.并且举例说明了存在非次正规的广义弱亚正规算子T使得T~t是次正规的.     

正规σ-集体正规空间的逆极限

本文得到如下结果：设Ｘ是逆系统｛Ｘα,πβ＾α,≤∧｝的极限,／∧／＝λ,假设每个投射πα;Ｘ→Ｘα是开且到上的,Ｘ是λ－仿紧的,如果每个Ｘα是正规σ－集体正规的,则Ｘ是集体正规的,进一步还要得到关于遗传σ－集体正规的类似结果。     

正规函数与正规族

研究了正规函数与正规族之间的联系,利用分担集合的方法得到一族满足特殊性质p的正规函数,同时利用分担值的方法得到了一个较已有结论更为一般的结果。     

Vague集上的正规距离与正规相似度

距离与相似度是Vague集上的一对对偶概念,给出了Vague集上加强的距离的公理化定义,引入了正规距离与正规相似度的概念,提出了Vague集上距离的一个一般公式,通过对Vague值的探讨给出了该一般公式成为正规距离的充分条件,同时得到Vague集上的一个新的正规距离公式.最后通过数据分析得出由此正规距离公式生成的正规相似度是合理有效的.     

初等算子的正规性

设初等算子E（X）＝n↑∑↑i=1AiXBi，定义E^*(X)=n↑∑↑i=1Ai^*XBi^*我们证明了EE^*＝E^*E当县仅当｛Ai｝和｛Bi｝都是交换的正规算子族，从而回答了由D.Keckic提出的关于初等算子正规性的开问题。我们还给出了E＝E^*的充分必要条件。     

正规六边形和更广泛具有正规结构的Banach 空间

假设Ｘ是一个实Ｂａｎａｃｈ空间,Ｓ（Ｘ）是单位球面。作者引进了一个新的几何参数（Ｈ（Ｘ）,讨论了Ｈ（Ｘ）和Ｎｅｕｍａｎｎ－Ｊｏｒｄａｎ常数ＣＮＪ（Ｘ）Ｒ 性质以及Ｈ（Ｘ）和其他几何常数的关系,本文主要结果是：Ｈ（Ｘ）〈２或ＣＮＪ（Ｘ）〈４／５一致正规结构。     

有限群的Fuzzy拟正规子群和Fuzzy次正规子群

讨论有限群的Fuzzy拟正规子群和Fuzzy次正规子群的一些性质。     

Spotlight Tiling

This article introduces spotlight tiling, a type of covering which is similar to tiling. The distinguishing aspects of spotlight tiling are that the “tiles” have elastic size, and that the order of placement is significant. Spotlight tilings are decompositions, or coverings, and can be considered dynamic as compared to typical static tiling methods. A thorough examination of spotlight tilings of rectangles is presented, including the distribution of such tilings according to size, and how the directions of the spotlights themselves are distributed. The spotlight tilings of several other regions are studied, and suggest that further analysis of spotlight tilings will continue to yield elegant results and enumerations.     

Natural Tiling, Lattice Tiling and Lebesgue Measure of Integral Self-Affine Tiles

In the existing theory of self-affine tiles, one knows thatthe Lebesgue measure of any integral self-affine tile correspondingto a standard digit set must be a positive integer and everyintegral self-affine tile admits some lattice Zⁿ as a translationtiling set of Rⁿ. In this paper, we give algorithms to evaluatethe Lebesgue measure of any such integral self-affine tile Kand to determine all of the lattice tilings of Rⁿ by K. Moreover,we also propose and determine algorithmically another type oftranslation tiling of Rⁿ by K, which we call natural tiling.We also provide an algorithm to decide whether or not Lebesguemeasure of the set K (K+j), j–Zⁿ, is strictly positive.     

Tiling Bricks with Bricks

The problem addressed by the paper is the filling of a large brick with replicas of smaller bricks of different sizes. We solve this problem by reducing it to an algebraic problem about polynomials. As a by-product, we obtain new combinatorial interpretations of the connection constants linking some classical polynomial sequences of combinatorics.     

One-dimensional Tiling Semigroups

We investigate the structure of Kellendonks tiling semigroup in the case of 1-dimensional tilings.     

Tiling polygons with parallelograms

Under what conditions can a simple polygon be tiled by parallelograms? In this paper we give matching necessary and sufficient conditions on the polygon to be tilable and characterize the set of possible tilings. We also provide an efficient algorithm for constructing a tiling.     

Tiling Infinite-Dimensional Normed Spaces

The present paper deals with real infinite-dimensional normedspaces; some of the main concepts here make sense, and havebeen treated in the literature, in the general context of topologicalHausdorff linear spaces over reals. A subset of a normed space X is a body if it is different fromX itself and is the closure of its non-empty interior. A coveringof X by bodies is called a tiling of X whenever any two differentmembers of it have disjoint interiors. The elements of sucha covering are called tiles. A tiling is bounded (respectivelyconvex) whenever each tile is bounded (respectively convex).1991 Mathematics Subject Classification 46B20.     

铺瓷砖问题的推广

铺瓷砖问题是数学模型中著名的问题,在研究了铺瓷砖问题的基础上,对其进行了推广,并给出了各种推广情形的结果.     

Neighborhoods of DOTU matrices

One derives sufficient conditions in order that a matrix from the neighborhood of a DOTU matrix be a DOTU matrix.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 91, pp. 171–179, 1979.     

Neighborhoods of sphere-like continua

Let X be an S^k-like continuum in Euclicean space Eⁿ. It is shown that if the embedding of X satisfies the small loops condition and 1⩽k⩽n−4, then X has arbitrarily small neighborhoods which are homeomorphic to S^k×B^n−k. It follows that if X and Y are S^k-like continua in Sⁿ, 1⩽k⩽n−4, and both satisfy the small loops condition, then X and Y have homeomorphic complements if and only if they have the same shape.