一图与其生成子图的全独立数

本文讨论一图与其生成子图全独立数之间的关系,得到加边运算下全独立数增加的充要条件和全独立数减小的必要条件。     

偶图中独立边集的1－因子扩张

Ｇ＝（Ａ，Ｂ；Ｅ）是偶图，｜Ａ｜＝｜Ｂ｜＝≥２，若ｅ，ｆ∈Ｅ，ｅ≠ｆ，有ｄ（ｅ）＋ｄ（ｆ）≥３ｎ＋ｋ（ｋ≥１），则Ｇ中所有ｋ个边的独立集Ｍ皆可扩张成Ｇ的１－因子．     

正则k-覆盖图

图G的k-正则生成子图称为G的一个k-因子,若图G的每条边都含于G的一个k-因子中,称图G足k-覆盖的。对任意给定的正整数γ、λ和k(λ≥2),基于文[1,2]的已知结论,本文给出了所有γ-正则λ-边连通图是k-覆盖图的充分必要条件。     

Testing implication of hierarchical log-linear models for probability distributions

The problem of the logical implication between two hierarchical log-linear models is proved to be equivalent to the problem of deciding whether their generating classes satisfy the graphtheoretic condition of hinging. Moreover, a polynomial-time procedure is worked out to test implication.     

Min-max最短路问题的双标号算法

在网络的两个顶点间的所有最短路中找一条Min-max路,即找一条使路中的任一顶点与所有顶点间的最大距离达到最小的最短路.在距离矩阵给定的条件下,以Dijkstra算法为基础,提出一个复杂性为0(n~3)的双标号算法来求Min-max最短路.     

灾变性事件引起的消费品产业链价格波及效应研究

为了研究地震等灾变性事件对于消费品产业链内价格传递和市场的影响,本文利用从2008年2月至2009年3月四川省江油市畜产业链进行实证研究,使用向量纠错模型(VECM)和历史分解图(HDG)分析了价格调整的动态效果和沿产业链的因果关系。结果表明,价格的调整关于速度和大小都是不对称的,外生震荡对于该产业链的不同层面产生不同影响,导致价格差益的扩大和价格不完全传递。该方法能够有效地分析灾变事件条件下消费品产业链内价格波及效应问题。     

Policy Stable States in the Graph Model for Conflict Resolution

A new approach to policy analysis is formulated within the framework of the graph model for conflict resolution. A policy is defined as a plan of action for a decision maker (DM) that specifies the DM’s intended action starting at every possible state in a graph model of a conflict. Given a profile of policies, a Policy Stable State (PSS) is a state that no DM moves away from (according to its policy), and such that no DM would prefer to change its policy given the policies of the other DMs. The profile of policies associated to a PSS is called a Policy Equilibrium. Properties of PSSs are developed, and a refinement is suggested that restricts DMs to policies that are credible in that they are in the DM’s immediate interest. Relationships with existing stability definitions in the graph model for conflict resolution are then explored.     

标号有向块的计数

根据图的计数中的基本定理和标号计数引理,利用标号有向图的指数型生成函数,讨论了标号有向连通图和标号有向块的计数问题。     

Revisiting asymmetric marriage rules

Although generalized exchange remains an emblematical model of alliance theory, characterizing matrimonial systems as pertaining to this model is tricky. The necessary condition of generalized exchange is the deliberate preference for asymmetric exchanges. Given a marriage dataset, can we determine whether the observed pattern is due to the realization of a social norm enjoining symmetric or asymmetric exchange or is the result of random processes? Here, relevant probabilities and indexes are established in the framework of graph theory, and are validated using a demographic individual-based model. The methods are applied to three datasets from the literature, allowing to assess with great confidence that the observed marriage configurations were not random.