Speeding up the FMMR perfect sampling algorithm: A case study revisited

In a previous paper by the second author, two Markov chain Monte Carlo perfect sampling algorithms—one called coupling from the past (CFTP) and the other (FMMR) based on rejection sampling—are compared using as a case study the move‐to‐front (MTF) self‐organizing list chain. Here we revisit that case study and, in particular, exploit the dependence of FMMR on the user‐chosen initial state. We give a stochastic monotonicity result for the running time of FMMR applied to MTF and thus identify the initial state that gives the stochastically smallest running time; by contrast, the initial state used in the previous study gives the stochastically largest running time. By changing from worst choice to best choice of initial state we achieve remarkable speedup of FMMR for MTF; for example, we reduce the running time (as measured in Markov chain steps) from exponential in the length n of the list nearly down to n when the items in the list are requested according to a geometric distribution. For this same example, the running time for CFTP grows exponentially in n. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003     

二阶积分微分方程周期边值问题的解的存在性

通过对比结果,用单调迭代方法证明了Banach空间中二阶积分微分方程的周期边值问题的最大最小解的存在性定理。     

Four-mode coherent-entangled state and its application

A new kind of four-mode continuous variable coherent-entangled state is proposed in the Fock space by using the technique of integration within an ordered product,which exhibits both the properties of a coherent state and an entangled state,and spans a complete and orthonormal representation.The conjugate state of the four-mode continuous variable coherent-entangled state is derived by using the Fourier transformation.Moreover,a simple experimental protocol of generating a four-mode continuous variable coherent-entangled state is proposed by using beam splitters.As applications of this four-mode continuous variable coherent-entangled state,a four-mode entangled state and a four-mode squeezing-Fresnel operator are constructed.     

高血压性脑出血再发生因素的Logistic分析

根据问题的特点 ,选择 Logistic判别模型 ,并借鉴普通线性回归的逐步向前法 ,用似然比统计量 ( Deviance)来筛选自变量 (因素 ) .结果显示 :在 1 1个因素中 ,有 3个是作用显著的 ,而其中舒张压值极为重要 .为降低再出血率 ,将其控制在 85 mm Hg以下是有效而可行的     

The monotone convergence theorem for multidimensional abstract Kurzweil vector integrals

We prove two versions of the Monotone Convergence Theorem for the vector integral of Kurzweil, , where R is a compact interval of , and f are functions with values on L(Z,W) and Z respectively, and Z and W are monotone ordered normed spaces. Analogous results can be obtained for the Kurzweil vector integral, , as well as to unbounded intervals R.     

On half cyclically ordered groups

In this paper we introduce and investigate the notion of half cyclically ordered group generalizing the notion of half partially ordered group whose study was begun by Giraudet and Lucas.     

Completeness and Admissibility for General Heuristic Search Algorithms—A Theoretical Study: Basic Concepts and Proofs

We propose a formal generalization for various works dealing with Heuristic Search in State Graphs. This generalization focuses on the properties of the evaluation functions, on the characteristics of the state graphs, on the notion of path length, on the procedures that control the node expansions, on the rules that govern the update operations. Consequently, we present the algorithm family and the sub-family Ã, which include Nilsson's A or A_* and many of their successors such as HPA, B, A ^* , A, C, BF^*, B, IDA^*, D, A^**, SDW. We prove general theorems about the completeness and the sub-admissibility that widely extend the previous results and provide a theoretical support for using diverse kinds of Heuristic Search algorithms in enlarged contexts, specially when the state graphs and the evaluation functions are less constrained than ordinarily.     

无限维空间中的实零点定理

在本文中，我们建立了无限维空间中的实零点定理，同时从仿射空间的拓扑结构和域的序结构两个方面，分别刻划了适合无限维实零点定理的序域．此外，本文有例子表明，对任意的基数α，确实存在适合α维实零点定理的序域．