Nonnegative Definiteness of the Sample Autocovariance Function

Various textbooks on time series analysis assert that the usual version of the sample autocovariance function (1) is nonnegative definite. Two simple proofs of this result are presented.     

Asymptotic properties of the bootstrap unit root test statistic under possibly infinite variance

ABSTRACT

In this article, the unit root test for the AR(1) model is discussed, under the condition that the innovations of the model are in the domain of attraction of the normal law with possibly infinite variances. By using residual bootstrap with sample size m < n (n being the size of the original sample), we bootstrap the least-squares estimator of the autoregressive parameter. Under some mild assumptions, we prove that the null distribution of the unit root test statistic based on the least-square estimator of the autoregressive parameter can be approximated by using residual bootstrap.     

Borrowing strength from past data in small domain prediction by kalman filtering - a case

Point and interval estimators for small domains based exclusively on current and domain specific sample observations are generally ineffective because of inadequate sample-sizes. So, borrowing strength from sample values for analogous domains and simultaneously from all relevant past and auxiliary data is useful in deriving improved small domain statistics. Postulating for simplicity a linear regression model with a single covariate and a zero intercept but a time-specific domain-invariant slope we start with “synthetic” generalized regression predictors for the domain totals. These borrow across only domains. For further improvements a simple autoregressive model is postulated for the slope parameters. Employing Kalman filtering the previous predictors are revised to borrow supplementary strength across time. As drastic simplifying assumptions are needed in such predictions the efficacy of the procedure is examined through an empirical exercise using live data as well as simulations. The numerical findings turn out encouraging.     

基于主观博弈的皖南与皖北旅游产业合作研究

论文运用主观博弈理论对皖南与皖北旅游产业合作进行分析,建立了旅游产业合作的主观博弈模型.研究表明,皖南与皖北旅游产业合作的初始域开始出现,皖南与皖北参与人要扩大旅游合作的共有信念,博弈域环境的诱发性变化亦在一定程度上加速了旅游合作共有信念的形成.最后,提出了促进皖南与皖北旅游产业合作的建议.     

Stability and Bifurcations in a Model of Bacteria Immunity with Quorum Sensing

Quorum sensing, a widespread phenomenon in bacteria that is used to coordinate gene expression among local populations, intervenes in the competition between bacteria and the immune system. The domain of attraction of the bacteria-free equilibrium results from a linear matrix inequality optimization with a multivariate polynomial objective under constraints. The Bogdanov-Takens singularity and bifurcation, including a saddle-node bifurcation, a Hopf bifurcation, and a homoclinic bifurcation, are obtained from normal form theory. The normal form of a bifurcation is a simple dynamical system which is equivalent to all systems exhibiting this bifurcation.     

Interval-wise testing for functional data

In the framework of null hypothesis significance testing for functional data, we propose a procedure able to select intervals of the domain imputable for the rejection of a null hypothesis. An unadjusted p-value function and an adjusted one are the output of the procedure, namely interval-wise testing. Depending on the sort and level α of type-I error control, significant intervals can be selected by thresholding the two p-value functions at level α. We prove that the unadjusted (adjusted) p-value function point-wise (interval-wise) controls the probability of type-I error and it is point-wise (interval-wise) consistent. To enlighten the gain in terms of interpretation of the phenomenon under study, we applied the interval-wise testing to the analysis of a benchmark functional data set, i.e. Canadian daily temperatures. The new procedure provides insights that current state-of-the-art procedures do not, supporting similar advantages in the analysis of functional data with less prior knowledge.     

序数表属性量级的双向性

属性值语素与属性域语素互相融合,是原型区别词的生成机制。序数表达属性量级具有明显的双向性：采用升序,数字越大,量级越高;采用降序,数字越大,量级越低。这在交际中常常造成含混与误解。序数表量级的双向性源于数词的中性色彩。最小正整数＂一＂在汉文化中具有无与伦比的重要地位,用来表示大量级是很自然的事情,采用降序是汉文化的优选原则。     

报纸版面与新闻网站首页设计之比较

报纸与新闻网站虽然属于两种新闻媒体,但由于它们使用的媒介有相同之处,因此在编排方式上就有共同规律可言。本文从版面空间、强势、板块与专栏、标题、图片、布局结构、版面的美化等七个方面对二者进行了比较,既发现了它们的共同点,又更清楚地认识了二者的不同,从而可以为提高新闻网站的设计水平提供更多的依据。     

哲学的界域与“界域哲学”

以“思维与存在关联”的思考（内涵）所展示的具体形态（外延）为对象的探究,构成界域哲学的基本内容。研究表明,哲学家以不同的公理、命题、原理、原则的设定,对“思维与存在关联”所作的诠释,构建了形态各异的哲学小“椭圆”界域。纵观哲学形态推进的演化,哲学界域是由“本体”-“认识”-“方法”-“人本”各异的小“椭圆”的首尾衔接叠加而成的大“椭圆”。     

当代中国社会公德建设的三个基本维度——腾讯与360商业争端的伦理反思

发生于2010年11月3日下午至4日凌晨的腾讯与360之间的商业争端,被认为是互联网上有史以来最为激烈的一场商业交锋,在互联网上,这场交锋还被网民演绎成为一个参与度极广且极深的娱乐话题。事件对当前我国社会公德建设的实践有着重要的启示意义:公德建设不是简单地提升个人道德素养或确立公共领域与公共生活的道德规范,在当代中国社会公德建设的实践中,三个方面亟需反思与加强:建构现代性公共生活领域,健全公共生活机制;培育公共意识与公共精神;加强制度供给。