核心城市房地产市场的联动和溢出特征研究——基于中国“北上广深”样本的经验考察

本文基于房价长期趋势和短期波动层面,基于HP滤波法分离北京、上海、广州和深圳四大一线城市的房价,采用有向无环图和信息溢出指数方法剖析了核心城市房价之间的同期联动效应和信息溢出效应,并结合滚动窗口估计法分析了信息溢出对外部信息和调控政策的反应程度。结果显示:一线城市房价之间有紧密的联系程度和较高的信息溢出规模。在同期联动效应上,深圳房价趋势的对外联动效应最明显,北京房价趋势在同期最易受其它城市影响;上海房价波动存在较强的对外联动效应,深圳房价波动受其它一线城市的波动冲击较迅速。在信息溢出效应上,深圳房价趋势有引领作用,对外溢出效应最强;上海房价波动处于引导地位,中长期对其它市场影响最大。核心城市房价趋势之间的溢出指数随着利好政策信息的出现而上升,随着限制政策等不利信息的出现而下降。核心城市房价波动之间的溢出效应对于外部信息反应更为灵敏,国家对房地产市场的调控政策增大核心城市房价波动的信息溢出规模。     

Analysis of a time-dependent scheduling problem by signatures of deterioration rate sequences

In the paper a single machine time-dependent scheduling problem is considered. The processing time p_j of each job is described by a function of the starting time t of the job, p_j=1+α_jt, where the job deterioration rate α_j?0 for j=0,1,…,n and t?0. Jobs are nonpreemptable and independent, there are no ready times and no deadlines. The criterion of optimality of a schedule is the total completion time.First, the notion of a signature for a given sequence of job deterioration rates is introduced, two types of the signature are defined and their properties are shown. Next, on the basis of these properties a greedy polynomial-time approximation algorithm for the problem is formulated. This algorithm, starting from an initial sequence, iteratively constructs a new sequence concatenating the previous sequence with new elements, according to the sign of one of the signatures of this sequence.Finally, these results are applied to the problem with job deterioration rates which are consecutive natural numbers, α_j=j for j=0,1,…,n. Arguments supporting the conjecture that in this case the greedy algorithm is optimal are presented.     

Influence diagrams for Bayesian decision analysis

Influence diagrams for representing Bayesian decision problems are redefined in a formal way using conditional independence. This makes the graphs somewhat more helpful for exploring the consequences of a clients state beliefs. Some important results about the manipulation of influence diagrams are extended and reviewed as is an algorithm for computing an optimal policy. Two new results about the manipulation of influence diagrams are derived. A novel influence diagram representing a practical decision problem is used to illustrate the methodologies presented in this paper.     

极小化完工时间和的有界批调度问题

考虑m台并行批加工同型机上n个带有释放时间的工件的调度问题,目标是极小化完工时间和.给出了一个多项时间近似方案.     

有向树的部分逆M矩阵完备及其算法设计

1 引言 M矩阵是具有非正非对角元且其逆是非负矩阵的一类矩阵．逆M矩阵是逆为M矩阵的一类非负矩阵．部分矩阵是指一个矩阵中一些元已定,其余未定元还可以自由选择的矩阵．如果在一个部分矩阵中,其每个已定的主子矩阵均为逆M矩阵并且所有已定元均是非负的,称这个部分矩阵是一个部分逆M矩阵．一个部分逆M矩阵的完备式是对     

战争地区邮递员问题

本文首次提出了赋权有向图上中国邮递员问题的一个推广－战争地区邮递员问题，并对解的存在性给出了若干充分条件和必要条件，得到了求解该问题的一个多项式算法。     

一类局部定向完备集及其范畴的性质

本文给出了局部定向完备集的概念及其在此结构下的一种新的双小于关系，从而进一步给出了一种新的连续性概念，接着讨论了局部定向完备集，连续的局部定向完备集等对象的一些性质，最后考察了三种范畴的笛卡儿闭性，并证明了范畴LDCPO是范畴ALG的反射满子范畴．     

关于剩余有限群的Profinite完备化

设G是个剩余有限群,本文深入地讨论了G的Profinite完备化之间的关系,得到了整齐的结     

A Tukey decomposition of 𝒫κλ and the tree property for directed sets

Generalizing a result of Todor?evi?, we prove the existence of directed sets D, E such that D ? ??_κλ and E ? ??_κλ but D × E ≥ ??_κλ in the Tukey ordering. As an application, we show that the tree property for directed sets introduced by Hinnion is not preserved under products. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Covering partially directed graphs with directed paths

We consider graphs which contain both directed and undirected edges (partially directed graphs). We show that the problem of covering the edges of such graphs with a minimum number of edge-disjoint directed paths respecting the orientations of the directed edges is polynomially solvable. We exhibit a good characterization for this problem in the form of a min-max theorem. We introduce a more general problem including weights on possible orientations of the undirected edges. We show that this more general weighted formulation is equivalent to the weighted bipartite b-factor problem. This implies the existence of a strongly polynomial algorithm for this weighted generalization of Euler's problem to partially directed graphs (compare this with the negative results for the mixed Chinese postman problem). We also provide a compact linear programming formulation for the weighted generalization that we propose.