Decomposing a -manifold

A splitting of a manifold in Kirby's problem list (no. 4.97) is given.

     

Old wine in fractal bottles I: Orthogonal expansions on self-referential spaces via fractal transformations

Our results and examples show how transformations between self-similar sets may be continuous almost everywhere with respect to measures on the sets and may be used to carry well known notions from analysis and functional analysis, for example flows and spectral analysis, from familiar settings to new ones. The focus of this paper is on a number of surprising applications including what we call fractal Fourier analysis, in which the graphs of the basis functions are Cantor sets, discontinuous at a countable dense set of points, yet have good approximation properties. In a sequel, the focus will be on Lebesgue measure-preserving flows whose wave-fronts are fractals. The key idea is to use fractal transformations to provide unitary transformations between Hilbert spaces defined on attractors of iterated function systems.     

Finite orthogonal transforms and multiresolution analyses on intervals

A class of fast orthogonal transformations for finite strings of data are described. These transformations are based on the multiresolution analysis paradigm of Mallat and Meyer and give rise to a method for constructing multiresolution analyses and orthogonal wavelets on an interval. Mathematical details and numerical examples are included.     

On the topology of the free complexes of convex geometries

We investigate the free complex of a convex geometry. Edelman and Reiner showed that the free complex of a convex geometry is contractible. Moreover, their paper stated a conjecture about the topology of free complexes. This paper proves their conjecture.     

Long cycles in 4-connected planar graphs

Let G be a 4-connected planar graph on n vertices. Malkevitch conjectured that if G contains a cycle of length 4, then G contains a cycle of length k for every k∈{n,n−1,…,3}. This conjecture is true for every k∈{n,n−1,…,n−6} with k≥3. In this paper, we prove that G also has a cycle of length n−7 provided n≥10.     

Structure of contractible locally -algebras

A locally -algebra is contractible iff it is topologically isomorphic to the topological cartesian product of a certain family of full matrix algebras.

     

Edges not contained in triangles and the number of contractible edges in a 4-connected graph

Let G be a 4-connected graph, and let E_c(G) denote the set of 4-contractible edges of G and let denote the set of those edges of G which are not contained in a triangle. Under this notation, we show that if , then we have .     

High school students’ understandings of geometric transformations in the context of a technological environment

This study investigated the nature of students’ understandings of geometric transformations, which included translations, reflections, rotations, and dilations, in the context of the technological tool, The Geometer’s Sketchpad. The researcher implemented a seven-week instructional unit on geometric transformations within an Honors Geometry class. Students’ conceptions of transformations as functions were analyzed using the APOS theory and were informed by an analysis of students’ interpretations and uses of representations of geometrical objects using the constructs of drawing and figure. The analysis suggests students’ understandings of key concepts including domain, variables and parameters, and relationships and properties of transformations were critical for supporting the development of deeper understandings of transformations as functions.     

Constructing an automorphic form from the orbit of a transformation

We consider the Fuchsian groups of linear-fractional transformations. We propose a new method for presenting automorphic forms as gap series over an appropriate subset of transformations of the group which is not a subgroup. Comparative analysis of the Poincaré theta-series and gap series demonstrates that the use of gap series requires less transformations and parameters that the summands of series depend on.     

Fuzzy格上的KKM定理

讨论定义和Ｆｕｚｚｙ格上的某类映射的性质,主要结果是定理２．１。近几攫来,国内外许多专家、学者热心研究的ＫＫＭ定理,广义ＫＫＭ定理等冼多结果,都是定理２．１的一些简单和推论。由此说明,Ｆｕｚｚｙ格理论具有广泛的应用性。     

Nonlinear Transformations of Smooth Measures on Infinite-Dimensional Spaces

We investigate the properties of the image of a differentiable measure on an infinitely-dimensional Banach space under nonlinear transformations of the space. We prove a general result concerning the absolute continuity of this image with respect to the initial measure and obtain a formula for density similar to the Ramer–Kusuoka formula for the transformations of the Gaussian measure. We prove the absolute continuity of the image for classes of transformations that possess additional structural properties, namely, for adapted and monotone transformations, as well as for transformations generated by a differential flow. The latter are used for the realization of the method of characteristics for the solution of infinite-dimensional first-order partial differential equations and linear equations with an extended stochastic integral with respect to the given measure.     

Linear transformations on codes

This paper studies and classifies linear transformations that connect Hamming distances of codes. These include irreducible linear transformations and their concatenations. Their effect on the Hamming weights of codewords is investigated. Both linear and non-linear codes over fields are considered. We construct optimal linear codes and a family of pure binary quantum codes using these transformations.     

Removable Edges in Longest Cycles of 4-Connected Graphs

Let G be a 4-connected graph. For an edge e of G, we do the following operations on G: first, delete the edge e from G, resulting the graph G–e; second, for all vertices x of degree 3 in G–e, delete x from G–e and then completely connect the 3 neighbors of x by a triangle. If multiple edges occur, we use single edges to replace them. The final resultant graph is denoted by Ge. If Ge is 4-connected, then e is called a removable edge of G. In this paper we obtain some results on removable edges in a longest cycle of a 4-connected graph G. We also show that for a 4-connected graph G of minimum degree at least 5 or girth at least 4, any edge of G is removable or contractible.Acknowledgment. The authors are greatly indebted to a referee for his valuable suggestions and comments, which are very helpful to improve the proof of our main result Lemma 3.3.Research supported by National Science Foundation of China AMS subject classification (2000): 05C40, 05C38, 05C75Final version received: March 10, 2004     

Jordan quadratic SSM-property and its relation to copositive linear transformations on Euclidean Jordan algebras

In this paper, we introduce Jordan quadratic SSM-property and study its relation to copositive linear transformations on Euclidean Jordan algebras. In particular, we study this relationship for normal Z-transformations, Lyapunov-like transformations and cone invariant transformations.     

Lotka-Volterra模型参数的灰色估计法及其应用

基于灰色直接建模法,提出了估计Lotka-Volterra模型参数的一种方法,较好的反映了相互影响的两个变量之间的互惠、竞争等关系,为定性预测分析提供了实证支持,并得到了定量预测的结果.实例说明本模型的有效性和适用性.并证明了数乘交换不影响原始序列的模拟精度,为解决灰色预测模型的病态性提供了思路.     

Spectral methods for weakly singular Volterra integral equations with pantograph delays

In this paper, the convergence analysis of the Volterra integral equation of second kind with weakly singular kernel and pantograph delays is provided. We use some function transformations and variable transformations to change the equation into a new Volterra integral equation with pantograph delays defined on the interval [-1, 1], so that the Jacobi orthogonal polynomial theory can be applied conveniently. We provide a rigorous error analysis for the proposed method in the L^∞-norm and the weighted L²-norm. Numerical examples are presented to complement the theoretical convergence results.     

Tangent Processes on Wiener Space

This paper deals with the study of the Malliavin calculus of Euclidean motions on Wiener space (i.e. transformations induced by general measure-preserving transformations, called “rotations”, and H-valued shifts) and the associated flows on abstract Wiener spaces.