书本图与齿轮图的子树计数及渐进密度特性分析

图的子树数拓扑指标对指导可靠性网络设计和分析化合物的物理与化学性质均具有重要意义.本文基于生成函数、结构分析及矩阵映射的方法给出书本图B_(n,2)(n≥2)和齿轮图G_(n,1)(n≥3)的子树数生成函数,并分析了B_(n,2)(n≥2)和G_(n,1)(n≥3)的子树密度的渐进特性,本研究为探索复杂圈图和分子的结构新特性提供了新的视角和方法.     

一种基于多级查找表的高效Huffman编码算法

本文研究了适用于数字信号处理器的一种高效的Huffman编码算法的问题.利用多级查找表建立规则,并将Huffman树分割为若干子树且为分割后的所有子树建立一个统一的查找表的方法,获得了可用较小的查找表来存储Huffman树且能对比特流进行快速解码的结果.     

顾客为子树结构的树上反中心选址问题

顾客为子树结构的树上反中心选址问题是在树T上寻找一点(位于顶点处或在边的内部),使得该点与子树结构的顾客之间的最小赋权带加数距离尽可能地大.给出了该问题的一个有效算法,其时间复杂度为O(cn+sum from j=1 to m n_j),其中n_j为各子树T_j的顶点个数,c为不同的子树权重个数,n为树的顶点数.     

一些图的生成树数

图 G 的生成树是它的连通子图(子树).本文精确地计算出了一些图的生成树的数目, 例如双心轮图、双柄扇图等等.     

机助故障树分析的统一算法

本文提出一种机助故障树分析的统一算法。该算法能给出原故障树的全部模块子树,各模块子树及其对偶模块子村的不交蕴涵族,原故障树的质蕴涵族,完成常规的定量计算和某些新的定量分析。它与Willie的算法相比较功能更全也更为有效。     

关于Corley求所有有效生成树算法的修正

Ｃｏｒｌｅｙ在（１）中提出了一个求所有有效生成树的算法。但是此算法得到的最终解含有许多非有效的生成树。本文修改了Ｃｏｒｌｅｙ算法，提出并证明一个子树是有效生成树的子树的两个必要条件，根据这个结果，我们建立了一个修正算法并证明了它的有效性，同时，Ｃｏｒｌｅｙ算法的缺点被克服了。     

圆锥曲线的统一作图法及一个有关的新定理

几种圆锥曲线:抛物线、椭圆和双曲线,根据它们自身的定义,可以得出各自独特的几何作法.根据圓锥曲线的统一定义,在极坐标下导出了它们的统一方程ρ=ep/1-ecosθ,由此,是否可以得出统一的几何作法呢?事实上,从圆锥曲线的统一定义“到定点和定直线的距离之比     

具有4pq阶自同构群的有限群

本文讨论了自同构群阶为4pq(p,q为不同奇素数)的有限群,得出了它们的构造.     

有限连续拓扑空间上的相交定理和广义变分不等式

根据已知的FC-空间上的KKM型定理得出若干个相交定理,作为它们的应用,利用转移开闭映射的特征讨论广义变分不等式解的存在问题.本文的结果改进和推广了文献中的相应结论.     

不同距离的双线性自适应模糊回归的最小二乘比较

针对双线性自适应模糊回归模型,采用了欧氏距离、Y-K距离和D_k距离,分别讨论了该模型的最小二乘估计及相关性质,得出在这三种距离下,它们的回归系数的最小二乘估计的形式是一致的仅仅系数不相同,且它们的观测中心和插入中心、设计边宽和插入边宽的误差和为0的结论.通过实例验证了上述结论的正确性.     

Historical systems as complex systems

All social systems are simultaneously historical and systemic. They have rules that govern their operation which are reflected in cyclical rhythms; they have irreversible patterns of development which are reflected in their secular trends, and which account for their eventual demise as systems. There are two varieties of complex historical systems: world-empires and world-economies. The latter variety has come to dominate in the period since 1500, leading to the elimination of all other varieties and creating the new situation of a planet with only one existing historical system. The consequences are explored.     

The variance and covariance of fuzzy random variables and their applications

The concepts of the variance and covariance of fuzzy random variables and their properties are introduced. Examples show their computation and applications in statistical estimation of parameters when samples or prior information are fuzzy. As their further applications the correlation function and the criterions of mean-square calculus for fuzzy stochastic processes are established.     

Hermitian LCD codes from cyclic codes

Cyclic codes are an interesting type of linear codes and have wide applications in communication and storage systems due to their efficient encoding and decoding algorithms. It was proved that asymptotically good Hermitian LCD codes exist. The objective of this paper is to construct some cyclic Hermitian LCD codes over finite fields and analyse their parameters. The dimensions of these codes are settled and the lower bounds on their minimum distances are presented. Most Hermitian LCD codes presented in this paper are not BCH codes.     

Discrete finite element characterizations of source fields for volume and boundary constraints in electromagnetic problems

The consideration of electromagnetic field sources in potential formulations necessitates the definition of source fields. Such source fields are first defined for both volume and boundary constraints in static electromagnetic models. Then, automatic procedures are proposed to conveniently and efficiently characterize discrete source fields, with regard to their use in finite element formulations, their supports, their direct expression requiring no pre-computation, and their associated constraints. Two application examples are proposed to illustrate the approach.     

Reliability verification for composite structures of annular cross section

The performance and reliability of tubular composite structures are considered. The suitability of concrete-filled plastic and steel tubes for building structures is discussed. The strength and structural safety of tubular composite members of annular cross section are analyzed, and the criteria of limit states for tubular composite members under concentric and eccentric axial compression are studied. The time-variant functions of efficiency of the members and their components are presented as random processes of variations in their compressive resistance and internal actions. The safety design of the members is based on the conceptions of their conventional resistance, sequences of safety margin, and transformed conditional probabilities.     

Behind the Masks: Identifying Students' Competencies for Learning Mathematics and Science in Urban Settings

Three mathematics and science educators reexamine and reflect on their teaching within the context of the American Association for the Advancement of Sciences (AAAS) and National Council of Mathematics' call to make math and science education accessible to all. The paper highlights the importance of teachers reflecting on their teaching practices in order to create opportunities for their students especially those in the urban setting. The educators argue that teachers' reflection on their teaching can cause them to recognize and validate their students' ways of knowing as they identify the students' hidden/concealed abilities that are often masked by their behaviors. The educators discuss their experiences and highlight the lessons that they learned about ways to prepare teachers to successfully teach math and science students in urban settings. Culturally responsive pedagogy and cultural competency are critical skills that teachers need to develop in order to teach all children, especially those in the math and science classroom in the urban setting.     

凹角型区域椭圆边值问题的自然边界归化

In this paper, the natural boundary reduction for some elliptic boundary value problems with concave angle domains and their natural boundary methods are investigated. The natural integral equations and the Poisson integral formulae are given. The finite element methods of the natural integral equations are discussed in details. The convergences of the approximate solutions and their error estimates are obtained. Finally, some numerical examples are presented to show that our methods are effective.     

直觉模糊关系的截集性质

定义了直觉模糊关系的截集以及并给出了它们的基本性质,同时分别讨论了自反、对称、传递直觉模糊关系与经典二元关系之间的等价刻画;其次,提出直觉模糊关系的定义域与值域的概念;最后,分析了直觉模糊关系合成的截集性质.