一个6点图与路的联图的交叉数

一个图G的交叉数cr(G)是把图G画在平面上,在所有画法中所产生的最少的交叉数.由于其结构的特殊性,能够确定两个图的联图交叉数的精确值的图类很少.本文通过圆盘画法这一途径,确定了一个特殊6点图与路P_n的联图的交叉数.     

K_m~-□P_n的交叉数

Klesc等人先后确定了K_m~-□P_n(4≤m≤6)的交叉数,本文利用构造法确定了K_m-2K_2(4≤m≤12,m≠10,12)的交叉数.在此基础上,可进一步确定K_m~-□P_n(4≤m≤9,m≠8)的交叉数.相比而言,我们所采用的方法更具一般性.     

一类具有三重量的循环码（英文）

本文研究了指数和S(α,β)=∑xx∈F_pm(αx~((p~k+1)/2)x+βx~((p~(3k)+1)/2))的值分布.应用S(α,β)的值分布,确定了一类p元循环码的重量分布,证明了所提出的循环码具有三个非零重量,这里p是奇素数,m和南是两个正整数,满足m/gcd(m,k)是奇数,k/gcd(m,k)是偶数以及m≥3.     

几类图弱控制的广义束缚数

对任一图G,其弱控制的束缚数,广义束缚数分别定义为bw(G)=min{|E‖E(∪)E(G),且γw(G-E)＞γω(G)}.b'ω(G)=min{t|(A)E(∪)E(G),如果|E|=t,则有γω(G-E)＞γw(G)}.在本文中我们给出了几类图的弱控制的广义束缚数的精确值,称b'ω(G)=1图为弱控制去边临界图,并研究了正则图是弱控制去边临界图的充要条件,以及一般图和树的必要条件.     

方差函数确定指数族的条件

本文以矩量问题的分布函数解为工具,给出了方差函数(V(m),M_0)确定REF(V(m),M)的充分必要条件.此外,作者还得到矩量问题有限支撑分布函数解存在的一个充分必要条件.     

关于Ramsey数r^＊（Cm^（≥）,Pn）

求Ramsey数的问题是图论中一个相当重要且难度较大的问题,并一直未获彻底解决。本文定义Ramsey数r(C_m~((≥)),P_n)为满足下述条件的最小整数:任何r(C_m~((≥)),P_n)阶简单图必含点数至少为m的圈C_m~((≥)),或其补图含P_n。这篇论文的主要结果就是求出r(C_m~((≥)),P_n)的精确值为:     

特殊图类的符号控制数

图G的符号控制数γS(G)有着许多重要的应用背景.已知它的计算是NP-完全问题,因而确定其上下界有重要意义.本文研究了1)一般图G的符号控制数,给出了一个新的下界;2)确定了Cn图的符号控制数的精确值.     

基于直觉不确定语言评价的群决策方法

针对直觉不确定语言评价的群决策问题,定义了直觉二元不确定语言数及其运算法则、期望值和精确值.提出了直觉二元不确定语言和(IBULS)算子以及加权平均(IBULWA)算子,并验证了IBULWA算子的性质,如单调性、幂等性和介值性.在此基础上,提出一种属性权重已知且属性值为直觉不确定语言信息的群决策方法.最后通过实例说明决策方法的有效性.     

一些完全非线性函数的原像分布值

确定完全非线性函数的原像分布值,是决定和分析完全非线性函数以及构造相应线性码的公开问题和重要课题之一.本文讨论了完全非线性函数的原像分布所满足的基本方程的求解问题,完全解决了该方程当m=5以及m=6时的情形.     

确定胎儿肺成熟度的“JWL 法(景、王、伦法)”研究及青岛地区胎儿肺成熟度的确定

胎儿肺成熟度的确定,在围产医学高危妊娠中非常重要.胎儿出生时如肺尚未成熟,会发生呼吸困难综合症,是由于肺缺乏表面活性物质.此物质主要成分是卵磷脂(L)和鞘磷脂(S),通过胎儿呼吸进入孕妇羊水,可由此测定其含量.L/S 比值随妊娠进程会发生一定变化,肺成熟时的比值,即胎儿肺成熟临界 L/S 值.国外仅求得临床经验胎儿肺成熟临界 L/S 值≥2.0,但缺乏理论依据,更无肺成熟临界孕周值求得.为此,本文研究出一种既可确定胎儿肺成熟临界 L/S 值,又可进一步确定胎儿肺成熟临界孕周值的理论和方法,称为确定胎儿肺成熟度的“JWL 法”.并运用此“JWL 法”确定出青岛地区胎儿肺成熟临界 L/S 值≥2.06,临界孕周值≥35.6周.经过临床实例验证,证实此“JWL 法”的正确和有效.     

关于超立方体网络的(d,k)独立数

(d,k)独立数是分析互连网络性能的一个重要参数.对于任意给定的图G和正整数d和k,确定G的(d,k)独立数问题是一个NPC问题.因此,确定一些特殊图的(d,k)独立数显得很重要.本文确定了k维超立方体网络的(d,k)独立数等于2,如果d=k≥4或者d=k-1≥6 以及αd,k-t(Qk)=αd,k(Qk),其中0≤t≤k-2,1≤d≤k-t-1.     

A note on a Cauchy problem for the Laplace equation: Regularization and error estimates

In this paper, a Cauchy problem for the Laplace equation is investigated. Based on the fundamental solution to the elliptic equation, we propose to solve this problem by the truncation method, which generates well-posed problem. Then the well posedness of the proposed regularizing problem and convergence property of the regularizing solution to the exact one are proved. Error estimates for this method are provided together with a selection rule for the regularization parameter. The numerical results show that our proposed numerical methods work effectively. This work extends to earlier results in Qian et al. (2008) [14] and Hao et al. (2009) [5].     

变换群性质的判定问题

In this paper the fundamental result about the decision problems for properties-of FRT-groups (i. e. the groups each of which is isomorphic with a group generated by a finite number of recursive transformations) has been proved: Let p be any algebraic property for groups such that there is a FRT -group G₁ which has the property p, a FRT-group G₂ which has not the property p, and G₂ is not isomorphic with any subgroup of any FRT-group which has the property p. Then the problem of deciding, for any given groap P genetated by a finite number of recursive transformations, whether or not the group G isomorphic with P has the property p is unsolvable.     

Localizability of the embedding problem with symplectic kernel

In this paper we consider the question of how much information is supplied by local solutions to a global embedding problem for the special case in which the normal subgroup belonging to the given group extension is the projective symplectic group PSp(2m, q). It is proved that for suitable Galois extensions K of a given number field k (which constitute part of the data of the embedding problem), the local solutions in a sense determine whether or not an extension K ? K, Galois over k, with $\text{G(}\text{L}\text{K}\text{) ≈ PSp(2m, q)}$, represents a global solution to the embedding problem.     

Exact penalty functions method for mathematical programming problems involving invex functions

In this paper, some new results on the exact penalty function method are presented. Simple optimality characterizations are given for the differentiable nonconvex optimization problems with both inequality and equality constraints via exact penalty function method. The equivalence between sets of optimal solutions in the original mathematical programming problem and its associated exact penalized optimization problem is established under suitable invexity assumption. Furthermore, the equivalence between a saddle point in the invex mathematical programming problem and an optimal point in its exact penalized optimization problem is also proved.     

给定顶点数和边数的连通图的Q-谱半径的界

图的无符号拉普拉斯矩阵是图的邻接矩阵和度对角矩阵的和,其特征值记为q1≥q2≥…≥qn.设C(n,m)是由n个顶点m条边的连通图构成的集合,这里1≤n-1≤m≤(n2).如果对于任意的G∈C(n,m)都有q1(G*)≥q1(G)成立,图G*∈C(n,m)叫做最大图.这篇文章证明了对任意给定的正整数a=m-n+1,如果n...     

An extremal problem in graph theory

It is proved that the maximum number of cut-vertices in a connected graph withn vertices andm edges is $$max\left\{ {q:m \leqq (_2^{n - q} ) + q} \right\}$$ All the extremal graphs are determined and the corresponding problem for cut-edges is also solved.     

An infinite family of type (m,n) sets in PG(2,q2), q a square

A k-set of type (m,n), with k=(q+√q+1)(q²?q+1), m= 1+√q, n=q+√q+1, is proved to exist in a Galois plane PG(2,q²), q a square, and its construction is given. Thus, its complement, i.e. a ((q?√q)(q+√q+1)(q²?q+1); √q(q√q?√q?1),√q(q √q?1))-set, exists too. The special case q=16 is considered and the points of a (91;3,7)-set in PG(2,16) are exhibited. A generalization is given.     

On injective enumerability of recursively enumerable classes of cofinite sets

To date the problem of finding a general characterization of injective enumerability of recursively enumerable (r.e) classes of r.e. sets has proved intractable. This paper investigates the problem for r.e. classes of cofinite sets. We state a suitable criterion for r.e. classesC such that there is a boundn with |-A|n for allAC. On the other hand an example is constructed which shows that Lachlan's condition (F) does not imply injective enumerability for r.e. classes of cofinite sets. We also look at a certain embeddability property and show that it is equivalent with injective enumerability for certain classes of cofinite sets. At the end we present a reformulation of property (F).Thank you for technical support, Wolfgang Eppler, for intellectual support, Alistair Lachlan, and for proof-reading, Martin Kummer. Thanks also to the anonymous referee