Optimal scaling of Metropolis algorithms: Heading toward general target distributions

The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example.     

中国人口性别结构的区域差异及演变动态分析

人口性别构成是影响人类婚姻、人口再生产的基本因素，也影响国家经济、政治、文化、教育等方面的发展，也是编制经济、文化、教育、科技、卫生、人民生活、劳动、城乡建设等发展规划的重要依据。同时对于中国当前正在进行的和谐社会建设也具有重要意义。利用中国五次人口普查资料及2005年1％人口抽样资料分析了中国总人口性别比演变动态及地理分布特征。表明：（1）中国在历史上是一个性别比偏高的国家，新中国总人口性别比呈下降趋势；（2）1953到2005年，年龄性别比曲线越来越平稳，性别比最高峰值呈现有低龄组向中龄组及高龄组转移的趋势；（3）各省区之间及城乡之间的性别结构差异由大变小；（4）山区性别比高于平原。重工业城市高于其他城市。大城市高于小城市。     

A bayesian estimator for the dependence function of a bivariate extreme‐value distribution

Any continuous bivariate distribution can be expressed in terms of its margins and a unique copula. In the case of extreme‐value distributions, the copula is characterized by a dependence function while each margin depends on three parameters. The authors propose a Bayesian approach for the simultaneous estimation of the dependence function and the parameters defining the margins. They describe a nonparametric model for the dependence function and a reversible jump Markov chain Monte Carlo algorithm for the computation of the Bayesian estimator. They show through simulations that their estimator has a smaller mean integrated squared error than classical nonparametric estimators, especially in small samples. They illustrate their approach on a hydrological data set.     

一种LOG-MAP算法的改进迭代实现及其结构

对LOG-MAP算法进行了可并发性分析,利用可以完整接收一个N长符号传输帧的条件以及正向迭代和反向迭代中的固有对称性质,提出了LOG-MAP算法的一种修正迭代实现算法,其正向和反向迭代计算次数只需码长N的一半,故比标准LOG-MAP算法提高了一倍的处理速度,且没有空间开销的增加、同时,根据修正的迭代实现算法给出了相应的适于FPGA实现的双总线硬件结构的实现方案。     

可以容忍的不平等：过渡与差别--柯亨思想的一种政治哲学考量

柯亨认为，马克思主义追求的社会主义理想是消除资本主义的阶级剥削，代之以经济平等和彻底的民主，但是，从历史和现实看，我们都距离马克恩的理想有很大距离。即使作为当前的合理目标是最好的选择，市场社会主义至多仍然是次优的选择。鉴于历史发展的进程要求，即过渡特征，我们必须对结果意义上的各种不平等采取包容政策。但在社会主义机会平等的条件下，收入差异在仅仅反映了不同的收入、闲暇差异时才是可以接受的。社会主义平等并非“机械的平等”或“结果的相同”。     

试论希腊神话和中国神话的差异及其影响

本文通过对希腊神话和中国神话的详细对比分析,阐述了希腊神话和中国神话的差异及其实质,以及其对社会的重要影响.同时指出在现代社会中,我们应吸取西方文化中的精华部分,以促进文化和文明的进一步发展.尤其在外语教学中应加强文化教育,以促进跨文化交际.     

以太网光桥的研究

根据有关网络技术和具体的实验,提出一种以太网光桥的实现方案,并对光桥的几个性能参数进行了分析讨论。     

分歧共识展望--10余年来国内全球化理论研究述评

由于主客观方面的多种原因，我国学者对全球化若干问题和理论观点的认识存在诸多分歧：全球化是客观的自然过程，还是主观的意识形态；全球化是单一的经济全球化，还是政治、文化、社会等整体的全球化；全球化是趋同化、一体化、单质化，还是多样化、民族化、异质化；全球化是物的全球化，还是人的全球化；等等。不同思想、观点相互碰撞、交锋，在争议中逐渐达成了一些基本共识：全球化至少经济全球化是一种客观存在；全球化是一种动态的过程；经济全球化不可避免地对世界政治、文化和社会生活产生影响；全球化具有主客观性：全球化过程内在地充满着矛盾；全球化是机遇与挑战并存，利益与弊端同在；现实的全球化是不公平的；等等。正确认识我国全球化理论研究中存在的问题，有利于明确下一阶段的努力方向。     

Domains of convergence for the EM algorithm: a cautionary tale in a location estimation problem

The EM algorithm is a popular method for maximizing a likelihood in the presence of incomplete data. When the likelihood has multiple local maxima, the parameter space can be partitioned into domains of convergence, one for each local maximum. In this paper we investigate these domains for the location family generated by the t-distribution. We show that, perhaps somewhat surprisingly, these domains need not be connected sets. As an extreme case we give an example of a domain which consists of an infinite union of disjoint open intervals. Thus the convergence behaviour of the EM algorithm can be quite sensitive to the starting point.     

Bayesian analysis of outlier problems using divergence measures

A Bayesian approach is presented for detecting influential observations using general divergence measures on the posterior distributions. A sampling-based approach using a Gibbs or Metropolis-within-Gibbs method is used to compute the posterior divergence measures. Four specific measures are proposed, which convey the effects of a single observation or covariate on the posterior. The technique is applied to a generalized linear model with binary response data, an overdispersed model and a nonlinear model. An asymptotic approximation using Laplace method to obtain the posterior divergence is also briefly discussed.