Unique factorization of compositive hereditary graph properties

A graph property is any class of graphs that is closed under isomorphisms. A graph property P is hereditary if it is closed under taking subgraphs; it is compositive if for any graphs G1, G2 ∈ P there exists a graph G ∈ P containing both G1 and G2 as subgraphs. Let H be any given graph on vertices v1, . . . , vn, n ≥ 2. A graph property P is H-factorizable over the class of graph properties P if there exist P 1 , . . . , P n ∈ P such that P consists of all graphs whose vertex sets can be partitioned into n parts, possibly empty, satisfying: 1. for each i, the graph induced by the i-th non-empty partition part is in P i , and 2. for each i and j with i = j, there is no edge between the i-th and j-th parts if vi and vj are non-adjacent vertices in H. If a graph property P is H-factorizable over P and we know the graph properties P 1 , . . . , P n , then we write P = H [ P 1 , . . . , P n ]. In such a case, the presentation H[ P 1 , . . . , P n ] is called a factorization of P over P. This concept generalizes graph homomorphisms and (P 1 , . . . , P n )-colorings. In this paper, we investigate all H-factorizations of a graph property P over the class of all hered- itary compositive graph properties for finite graphs H. It is shown that in many cases there is exactly one such factorization.     

Transition distributions of young diagrams under periodically weighted plancherel measures

Kerov[16,17] proved that Wigner＇s semi-circular law in Gauss[an unitary ensembles is the transition distribution of the omega curve discovered by Vershik and Kerov[34] for the limit shape of random partitions under the Plancherel measure. This establishes a close link between random Plancherel partitions and Gauss[an unitary ensembles, In this paper we aim to consider a general problem, namely, to characterize the transition distribution of the limit shape of random Young diagrams under Poissonized Plancherel measures in a periodic potential, which naturally arises in Nekrasov＇s partition functions and is further studied by Nekrasov and Okounkov[25] and Okounkov[28,29]. We also find an associated matrix mode[ for this transition distribution. Our argument is based on a purely geometric analysis on the relation between matrix models and SeibergWitten differentials.     

Gargano,Lewinter and Malerba问题的解

§1　IntroductionLet G be a graph with vertex-set V(G) ={ v1 ,v2 ,...,vn} .A labeling of G is a bijectionL:V(G)→{ 1,2 ,...,n} ,where L (vi) is the label of a vertex vi.A labeled graph is anordered pair (G,L) consisting of a graph G and its labeling L.Definition1.An increasing nonconsecutive path in a labeled graph(G,L) is a path(u1 ,u2 ,...,uk) in G such thatL(ui) + 1相似文献   

CONSTRUCTION OF SOME KIESSWETTER-LIKE FUNCTIONS-THE CONTINUOUS BUT NON-DIFFERENTIABLE FUNCTION DEFINED BY QUINARY DECIMAL

In this paper, we construct some continuous but non-differentiable functions defined by quinary decimal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of graphs of these functions and give a detailed proof.     

A sufficient condition for Hamiltonian cycles in bipartite tournaments

In this paper, we present a new sufficient condition on degrees for a bipartite tournament to be Hamiltonian, that is, if an n × n bipartite tournament T satisfies the condition W(n - 3), then T is Hamiltonian, except for four exceptional graphs. This result is shown to be best possible in a sense.     

《科技导报》作者服务指南

01著作权敬请本刊作者允诺:稿件中没有侵犯他人著作权或其他权利的内容;投寄给本刊的稿件(论文、图表、照片等)自发表之日起,其专有出版权和网络传播权即授予本刊,     

PROLOG抽象分析及在并行性分析中的应用

深入研究了Ｐｒｏｌｏｇ抽象分析，并将其应用到Ｐｒｏｌｏｇ的并行化编译开发中．用这一技术开发出的模型是采用动静态结合的方式，它改进了ＤｅＧｒｏｏｔ算法，在一定程度上避免了并行性的损失。这是一种动态开销小，并行性程度高，无需增加用户负担的新方法，利用Ｑｕｉｎ－ｔｕｓＰｒｏｌｏｇ在Ｓｕｎ３／２６０上实现了一开发逻辑程序中与并行性的静态预编译系统。     

Formal Verification under Unknown Constraints

We present a formal method of verifying designs with unknown constraints (e, g. , black boxes) using Boolean satisfiability (SAT). This method is based on a new encoding scheme of unknown constraints, and solves the corresponding conjunctive normal form (CNF) formulas. Furthermore, this method can avoid the potential memory explosion, which the binary decision diagram (BI)I)) based techniques maybe suffer from, thus it has the capacity of verifying large designs. Experimental results demonstrate the efficiency and feasibility of the proposed method.     

基于DirectX软件包进行三维图形的开发应用

介绍了3D图形技术应用的概况和Windows平台上DirectX编程的框架结构，及利用DirectX8.1软件包进行3D图形开发应用的一些基本概念。用Visual Basic进行了实践，建立了一个3D数据图表控件（DX Chart)，叙述了此控件的设计规划与具体实现。     

生物学网络信号教学模式的构建

通过对理论依据、制作方法、教学程序、教学评价、注意事项等方面的阐述，介绍一种以心理学教学论知识为基础，充分体现学生自主学习，融科学性、逻辑性、直观性、趣味性为一体的生物学教学模式。