亚纯函数及其导数的唯一性

本文证明了如下结果：设ｋ，ｎ是两个正整数，ａ，ｂ，ｗ是三个有穷复数，满足ａⁿ≠ｂⁿ，ｗⁿ＝１．如果一开平面上的亚纯函数ｆ（ｚ）以及它的ｋ阶导数ｆ^(k)（ｚ）分担两个集合S₁={awⁱ| i=1,2,…, n} , S₂={bwⁱ| i=1,2,…,n}，则ｆ（ｚ）≡ｔｆ^(k)（ｚ），其中ｔⁿ＝１．     

退化拟共形映射的整体同胚与二维奇异积分方程

设Ｄ是一个边界Г∈C_a¹（０＜a≤１）的有界单连通域,复函数ｑ（ｚ）∈C_a¹,|ｑ（ｚ）|≤１,等式只能在Г上成立,且在Г上等式ｑ（ｚ（ｔ）)ｚ′（ｔ）/ｚ′（ｔ）+1|_z∈Г＝０最多在有限个点上成立．本文给出了复伸张ｑ（ｚ）满足上述条件时的退化拟共形映射的整体同胚解及以ｑ（ｚ）为系数的一类二维奇异积分方程的解．     

关于一类微分方程周期解的存在性的注记

本文主要探讨下列周期系数微分方程dy/dt=(A₁(t)y+A₂(t)y²+A₃(t)y³)/(a₀(t)+a₁(t)y+a₂(t)y²)(**)的周期解个数问题，利用方程（**）解的差率法得到了方程（**）周期解的个数定理．本文仅在Ａ_i（ｔ），ａ_j（ｔ）（ｉ＝１，２，３，ｊ＝０，１，２）是连续周期函数的条件下得到这一结论，从而减弱了文［２］中相应定理的条件，即Ａ_i（ｔ），ａ_j（ｔ）均是连续可微的周期函数．     

非线性奇异扩散方程的第二初边值问题

讨论了非线性奇异扩散方程的第二初边值问题，证明了存在唯一的光滑解，且解关于初值是连续依赖的．同时还简洁地得到解的渐近性质：ｔ^ｌ｜ｕ－ｕ_０｜→０，０＜ｌ＜１/２．     

解在QK 型及Dirichlet 型空间中的线性微分方程

对于单位圆盘上系数函数是解析函数的复微分方程
f⁽ⁿ⁾+A_n-1(z)f^(n-1)+…+A₁(z)f''+A₀(z)f=0,
给出了方程的系数函数和解函数之间的关系, 即当系数函数A_j 满足给定的条件时, 方程的所有解属于Q_K型空间和Dirichlet 型空间.     

双曲型时滞偏差分方程解的振动性

本文主要讨论了双曲型时滞偏差分方程(?)的所有解振动的充分必要条件和振动性的判别准则,其中ａ－１≠０,ｐ＋ａ＞０,ｑ_ｉ是实数,ｋ_ｉ,ｌ_ｉ是非负整数,ｕ是一个正整数,ｉ＝１,２,…,ｕ.     

一类函数空间的刻画

在Ｏｒｌｉｃｚ空间Ｌ_p（Ｒ^ｎ）中给出一类于空间Ｃ_p^a（Ｒ^ｎ）,利用一标准算子序列的逼近,得到 其等价刻画．     

体上右线性方程组的反问题

设Ｆ，Ｋ，Ω分别表示一个任意的体、一个具有对合反自同构的体和一个实四元数体，Ｆ^ｎ表示Ｆ上的ｎ维右向量空间．本文推广和改进了实线性方程组的反问题及一系列结果，解决了Ｆ上右线性方程组更具一般性的反问题（简称ＩＰＳ）：给定ｂ∈Ｆ^s和α_ｉ∈Ｆ^ｎ（ｉ＝１，…，ｍ≤ｎ）满足ｒａｎｋ［α₁，…，α_m］＝ｍ，求所有的ｓ×ｎ矩阵Ａ使Ａα_ｉ＝ｂ（ｉ＝１，…，ｍ）．当ｓ＝ｎ时     

α型β级Bazilevic函数的Fekete-Szeg?问题

设Ｂ（α，β）（α＞０，０≤β＜１）表示在单位圆盘内定义的规范化的α型β级Ｂａｚｉｌｅｖｉｃ函数类．本文对Ｂ（α，β）中函数ｆ（ｚ）＝ｚ＋∑from∞to(ｎ＝２)ａ_ｎｚ^ｎ得到｜ａ３－λａ₂²｜（０≤λ≤１）的准确估计．     

Oppenheim不等式推广的简单证明

设Ｅｕｃｌｉｄ空间ｎ＋１元点集Ａ，Ｂ及其度量和Ｃ所构成的单形的体积、外接球半径分别为Ｖ_１，Ｖ₂，Ｖ和Ｒ_１，Ｒ₂，Ｒ．本文给出不等式V^2/n≥V₁^2/n+V₂^2/n,R²≤R₁²+R₂²一种简单的证法．该     

Estimation of the number of components of finite mixtures of multivariate distributions

An estimator of the number of components of a finite mixture ofk-dimensional distributions is given on the basis of a one-dimensional independent random sample obtained by a transformation of ak-dimensional independent random sample. A consistency of the estimator is shown. Some simulation results are given in a case of finite mixtures of two-dimensional normal distributions.     

Galois Structure of K-Groups of Rings of Integers

N/Kbe a Galois extension of number fields with finite Galois group G.We describe a new approach for constructing invariants of the G-module structure of the K groups of the ring of integers of N in the Grothendieck group of finitely generated projective Z[G]modules. In various cases we can relate these classes, and their function field counterparts, to the root number class of Fröhlich and Cassou-Noguès.     

Eigenvector p-Bases of Rings of Constants of Derivations

Let A be a UFD of characteristic p > 0, let 𝒵 be a set of some eigenvectors of a derivation of A. We prove, under some additional assumptions, a necessary and sufficient condition for 𝒵 to be a p-basis of the minimal ring of constants containing 𝒵. The main preparatory result is the unique decomposition theorem with respect to a factor from a given subalgebra containing A^p.     

有资格限制的指派问题的求解方法

在实际的指派工作中，常会遇到某个人有没有资格去承担某项工作的问题，因此，本建立了有资格限制的指派问题的数学模型。在此数学模型中，将效益矩阵转化为判定矩阵，由此给出了判定此种指派问题是否有解的方法；在有解的情况下，进一步将效益矩阵转化为求解矩阵，从而将有资格限制的指派问题化为传统的指派问题来求解。最后给出了一个数值例子来说明这样的处理方法是有效的。     

L－fuzzy集网的R－收敛性质

本文在ＬＦ拓扑空间中建立了Ｌ－ｆｕｚｚｙ集网的弱收敛（Ｒ－收敛）概念，应用文［４］中的Ｒ－闭包，系统讨论了它们的性质，证明了等式ＲｌｉｍＡ＿ｎ＝∧（∨Ａ＿ｍ）＿Ｒ和ＲｌｉｍＡ＿ｎ＝Ａ＿ｎ＝∧（∨Ａ＿ｍ）＿Ｒ并且给出了Ｌ－ｆｕｚｚｙ集网与其子网之间的关系。     

On Sums of Coefficients of Products of Polynomials

We study the nilpotency of the sums of all coefficients of some sorts of products of polynomials over reversible, IFP, and NI rings, and introduce an SCN ring as a generalization. We characterize SCN rings in relation with related ring properties, and also provide several useful properties and ring extensions of SCN rings.     

Convergence of sequences of sets of associated primes

It is a well-known result of M. Brodmann that if is an ideal of a commutative Noetherian ring , then the set of associated primes of the -th power of is constant for all large . This paper is concerned with the following question: given a prime ideal of which is known to be in for all large integers , can one identify a term of the sequence beyond which will subsequently be an ever-present? This paper presents some results about convergence of sequences of sets of associated primes of graded components of finitely generated graded modules over a standard positively graded commutative Noetherian ring; those results are then applied to the above question.

     

两种图多项式根的重数的一个注记

设P1，P2，……，Pt是几乎覆盖图G的l条不相交的路，s是没有被这些路覆盖的孤立点数．本证明：(i)匹配多项式μ(G，x)的非零根的重数最多是l，零根的重数最多l s。（ii)对于不含三角形的n阶图G，伴随多项式h(G，x)的非零根的重数最多是l，零根的重数最多是1/2(n l s)．(iii)对一种含三角形的所谓A型图，（ii）也成立．     

任意矩阵的特征值的扰动估计

设A和B是两个任意的n阶方阵,其特征值分别为{λ_1,…,λ_n}和{μ_1,…,μ_n}.本文对此两组特征值的如下“距离”的界给出了若干估计: B对于A的谱改变量 A与B的特征值的改变量这里的结果包含了Bauer-Fike定理,并且优于Kahan-Parlett/Jiang定理及Chu,施和肖所得出的结果.     

Rates of Convergence of Means of Euclidean Functionals

Let L be the Euclidean functional with p-th power-weighted edges. Examples include the sum of the p-th power-weighted lengths of the edges in minimal spanning trees, traveling salesman tours, and minimal matchings. Motivated by the works of Steele, Redmond and Yukich (Ann. Appl. Probab. 4, 1057–1073, 1994, Stoch. Process. Appl. 61, 289–304, 1996) have shown that for n i.i.d. sample points {X ₁,…,X _n } from [0,1] ^d , L({X ₁,…,X _n })/n ^(d−p)/d converges a.s. to a finite constant. Here we bound the rate of convergence of EL({X ₁,…,X _n })/n ^(d−p)/d . Y. Koo supported by the BK21 project of the Department of Mathematics, Sungkyunkwan University. S. Lee supported by the BK21 project of the Department of Mathematics, Yonsei University.