Engel连分数展式中的若干度量性质

摘要：研究了Engel连分数展式的度量性质．与普通连分数一样，证明了部分商的增长性满足0-1率．通过构造一族恰当的集合，得到了部分商增长速度的上下极限．     

Engel连分数中一个例外集的Hausdorff维数

本文研究了Engel连分数展式中部分商以某种速度增长的集合的Hausdorff维数.利用自然覆盖和质量分布原理,得到了集合B(α)={x∈(0,1):lim n→∞ log bn+1(x)/log bn(x)=α}的Hausdorff维数是1/α的结果.     

形式级数域中具有某种连分数展式集合的Hausdorff维数

本文研究了形式级数域中若干连分数例外集.利用质量分布原理和构造特殊覆盖,得到了当连分数展式部分商的度分别以多项式速度和指数速度趋向无穷大时,分别对应例外集的Hausdorff维数.     

具有正密度部分商序列的连分数(英文)

对任意的x∈[0,1),令x=[a_1(x),a_2(x),···]是它的连分数展式.依照TONGWANG的定义,我们称实数x是一个Szemerédi点,如果它的连分数展式中部分商序列{a_n(x)}_n≥1是严格单增的且包含任意长的算术级数.Szemerédi曾证明了具有正的上Banach密度的整数序列一定包含任意长的算术级数.在本文中,研究其部分商序列单增且具有正的上Banach密度的点组成的集合,证明该集合的豪斯多夫维数为1/2,这包含了之前TONGWANG的结果.     

形式级数域上Engel级数展式中“数字”次数的增长速度

WU在2003年研究了形式级数域上Engel级数展式中"数字"的次数以线性速度增长的例外集,并利用质量分布原理证明了该例外集具有满Hausdorff维数.本文我们主要研究形式级数域上Engel级数展式中"数字"的次数以多项式和指数速度增长的例外集,并给出他们的Hausdorff维数估计.     

奇妙的无穷连分数

一、什么是无穷连分数设ai(i∈N )都是正整数,称为无穷连分数,例如这里a1=1,an=2(n∈N,n≥2).     

有趣的连分数

连分数是初等数论中一个古老的课题 ,而且是极具艺术魅力的一部分 ,它曾经吸引了不少数学大师为之着迷 ,今日仍是一个十分有用的数学工具 .它既可以用于整数理论的探索 ,也可以用于整数、函数的近似求解 ,还可以用于线性递推数列性质的研究以及不定方程 (如 Pell方程 x2 -dy2=± 1,d是大于 1的非平方数 )的求解等等 .在计算机领域 ,连分数为复杂的数学计算近似求解提供了有效的理论工具 ,有力地推动了应用数学的发展 .在中学数学竞赛中 ,应用连分数解题也是常用的解题技巧 .本文将简要地介绍连分数的一些基本概念 ,并对 d与 di的连分数展开…     

连分数展式基本区间长度的比较

连分数是度量数论、Diophantine逼近理论中一个十分重要的领域,其基本区间的长度在相关度量理论、维数研究中起到十分重要的作用.本文给出了连分数展式基本区间长度的比较关系.     

局部Jarník-Besicovitch定理的一个简单证明

任意的无理数x,其无理指数δx∶=sup{δ≥0∶|x-pq-1|≤q-2δi.o.pq-1}衡量x可以被有理数逼近的程度.经典的Jarník-Besicovitch定理表明,对于任意的δ≥1,集合{x∈R∶δx≥δ}的Hausdorff维数为δ-1.Barral和Seuret[1]考虑该定理的局部化问题,证明对于任意的连续函数f∶R→[1,+∞),集合{x∈R∶δx≥f(x)}的Hausdorff维数为(inf{f(x)∶x∈R})-1.本文从经典的Jarník-Besicovitch定理出发,利用连分数的理论给出局部Jarník-Besicovitch定理一个简短的证明.     

实二次域上理想类的zeta-函数在-1处的值

用连分数给出了实二次域理想类的zeta-函数-1处值的一个具体的计算公式.     

Graphs with disjoint dominating and paired-dominating sets

A dominating set of a graph is a set of vertices such that every vertex not in the set is adjacent to a vertex in the set, while a paired-dominating set of a graph is a dominating set such that the subgraph induced by the dominating set contains a perfect matching. In this paper, we show that no minimum degree is sufficient to guarantee the existence of a disjoint dominating set and a paired-dominating set. However, we prove that the vertex set of every cubic graph can be partitioned into a dominating set and a paired-dominating set.     

多面体集下多目标优化问题近似解的若干性质

研究了多目标优化问题的近似解. 首先证明了多面体集是 co-radiant集,并证明了一些性质. 随后研究了多面体集下多目标优化问题近似解的特殊性质.     

On essential sets and essential components of efficient solutions for vector optimization problems

In this paper, we first introduce the notions of an essential set and an essential component of the set of efficient solutions for continuous vector optimizations on a nonempty compact subset of a metric space. Then we show that for each of these vector optimizations, each set of all efficient solutions corresponding to the same optimal values is essential. Basing on this result, we give full characterizations of an essential point, an essential set and an essential component, respectively. As an application, we prove that for continuous quasiconvex vector optimization problems on a nonempty compact subset of a metric vector space, each component of the set of efficient solutions is essential even though the efficient solution set is not connected.     

随机次自相似集的表示

本文引进了随机次自相似集与随机推移集的概念,讨论了随机次自相似集的结构,并证明了任一随机集是随机次自相似集的充分必要条件是：该随机集可以表为某一个随机推移集的某个像集。     

Dual characterizations of set containments involving uncertain polyhedral sets in Banach spaces with applications

In this paper, we first give a dual characterization for set containments defined by lower semi-continuous and sublinear functions on Banach spaces. Next, we provide dual characterizations for robust polyhedral containments where a robust counterpart of an uncertain polyhedral set is contained in another polyhedral set or a polyhedral set is contained in a robust counterpart of an uncertain polyhedral set. Finally, as an application, we derive Lagrange multiplier characterizations for robust solutions of the robust uncertain linear programming problems.     

Some similarity measures of intuitionistic fuzzy sets and their applications to multiple attribute decision making

Atanassov (1986) defined the notion of intuitionistic fuzzy set, which is a generalization of the notion of Zadeh’ fuzzy set. In this paper, we first develop some similarity measures of intuitionistic fuzzy sets. Then, we define the notions of positive ideal intuitionistic fuzzy set and negative ideal intuitionistic fuzzy set. Finally, we apply the similarity measures to multiple attribute decision making under intuitionistic fuzzy environment.     

关于满足弱开集条件的自相似测度的局部维数的注记

对于自相似集合,已知开集条件与强开集条件是等价的,我们讨论了强开集条件的基些性质,并给出了自似测度局部维数研究的一个应用。     

Set graphs. I. Hereditarily finite sets and extensional acyclic orientations

A graph $G$ is said to be a set graph if it admits an acyclic orientation which is also extensional, in the sense that the out-neighborhoods of its vertices are pairwise distinct. Equivalently, a set graph is the underlying graph of the digraph representation of a hereditarily finite set.In this paper, we initiate the study of set graphs. On the one hand, we identify several necessary conditions that every set graph must satisfy. On the other hand, we show that set graphs form a rich class of graphs containing all connected claw-free graphs and all graphs with a Hamiltonian path. In the case of claw-free graphs, we provide a polynomial-time algorithm for finding an extensional acyclic orientation. Inspired by manipulations of hereditarily finite sets, we give simple proofs of two well-known results about claw-free graphs. We give a complete characterization of unicyclic set graphs, and point out two NP-complete problems closely related to the problem of recognizing set graphs. Finally, we argue that these three problems are solvable in linear time on graphs of bounded treewidth.     

On Rough ℐ2-Convergence of Double Sequences

In this study, we introduce the notion of rough ?₂-convergence and the set of rough ?₂-limit points of a double sequence and obtained two rough ?₂-convergence criteria associated with this set. Later, we proved that this set is closed and convex. Finally, we examined the relationships between the set of cluster points and the set of rough ?₂-limit points of a double sequence.