On a class exhibiting trend change in average failure rate

Abstract

Weak convergence and moment convergence issues are investigated for the New Better than Average Failure Rate (NBAFR) family (introduced by Loh (1984 Loh, W. Y. 1984. A new generalization of the class of NBU distributions. IEEE Transactions on Reliability R-33 :97–113[Crossref], [Web of Science ®] , [Google Scholar])). We explore the validity of these results in the context of a more general ageing class that we introduce. We prove some new properties of this class and derive its interrelationships with other non-monotonic ageing families. Reliability and moment bounds are obtained and an interesting characterization of exponentiality is proved. Special cases of our results lead to new theorems for the NBAFR class. Finally weak convergence and related issues are established for this class.     

GPS接收机P(Y)直捕方法研究

GPS接收机P(Y)直捕算法是基于存储的滑动相关搜索,并利用FFT将时频二维联合搜索变成时域一维搜索。同时,考虑位同步点已知的条件,接收资源池只需存储一段接收序列,缩短了捕获时间且利于硬件实现。仿真结果表明,多普勒频移为±5kHz时,所带来的峰值衰减为2dB左右,本地信号与接收信号对齐时出现明显的相关峰,很好地实现了捕获功能;提出了用重叠分段补零FFT操作实现并行相关,成倍降低了捕获时间;提出了利用位同步信息,避免了码极性翻转可能引起的信噪比损耗;针对码相位漂移,提出了优化捕获策略,可在短时间内完成重捕。     

汉语生成的基本过程

应用唯物辩证法方法，研究汉语生成的基本过程。该过程和认识论有直接的联系，两者的主体结构是相互对应的。汉语是在一个疑问词的两次大分裂中生成的，具体表现为感觉=知觉＋概念的形式。日常生活中总体上驾驭人们实践的东西，既不是单纯的感性认识也不是单纯的理性认识，而是中和了这两个方面的感觉。过去认识论和心理学的基本观点是错误的，鉴于思维和语言的关系，有可能在此项研究中得到修正。     

在中国特色社会主义新起点上推进新的思想解放

解放思想，是党的思想路线的本质要求，是我们应对前进道路上各种新情况新问题、不断开创事业新局面的一大法宝，是中国特色社会主义的思想精髓。要把中国特色社会主义事业不断推向前进，必须在新起点上推进新的思想解放。     

NURBS曲面的算法分析及实现

讨论了ＮＵＲＢＳ曲线和节点矢量、控制点和基函数对曲面形状的影响，给出了ＮＵＲＢＳ的算法分析及其实现方案，最后，将ＮＵＲＢＳ曲面与老式曲面（如Ｂ样条、Ｂｅｚｉｅｒ曲面等）进行了比较。     

切入“历史”后的视点——论“新历史小说”的叙事角度

“新历史小说”，自生成之日起就存在着命名、指认等一系列问题上的争议，这一现象的出现，除了与其自身内涵和外延的不确定性有关之外，还与其叙事上的独特角度密不可分。有鉴于此，结合“新历史小说”出现的时代背景，通过对其结构特质的三个主要方面，即第一人称视角与“历史”同步、聚焦变换与情感演绎、民间视野及其视点应用进行阐释，就成为一道重要的逻辑线索。     

BATHTUB-TYPE CURVES IN RELIABILITY AND BEYOND

Finding optimal, or at least good, maintenance and repair policies is crucial in reliability engineering. Likewise, describing life phases of human mortality is important when determining social policy or insurance premiums. In these tasks, one searches for distributions to fit data and then makes inferences about the population(s). In the present paper, we focus on bathtub‐type distributions and provide a view of certain problems, methods and solutions, and a few challenges, that can be encountered in reliability engineering, survival analysis, demography and actuarial science.     

谈分级显性意义假说对反语中的认知参照点的解释力

本文运用Giora的分级显性意义假说分析了Langacker的认知参照点理论，并对反语中的认知参照点进行分析，得出反语中的认知参照点也是层级突显的结论，为反语的理解提供一个新的视角。     

Causal Reasoning from Longitudinal Data*

Abstract. This paper reviews some of the key statistical ideas that are encountered when trying to find empirical support to causal interpretations and conclusions, by applying statistical methods on experimental or observational longitudinal data. In such data, typically a collection of individuals are followed over time, then each one has registered a sequence of covariate measurements along with values of control variables that in the analysis are to be interpreted as causes, and finally the individual outcomes or responses are reported. Particular attention is given to the potentially important problem of confounding. We provide conditions under which, at least in principle, unconfounded estimation of the causal effects can be accomplished. Our approach for dealing with causal problems is entirely probabilistic, and we apply Bayesian ideas and techniques to deal with the corresponding statistical inference. In particular, we use the general framework of marked point processes for setting up the probability models, and consider posterior predictive distributions as providing the natural summary measures for assessing the causal effects. We also draw connections to relevant recent work in this area, notably to Judea Pearl's formulations based on graphical models and his calculus of so‐called do‐probabilities. Two examples illustrating different aspects of causal reasoning are discussed in detail.     

Practical Maximum Pseudolikelihood for Spatial Point Patterns(with Discussion)

This paper describes a technique for computing approximate maximum pseudolikelihood estimates of the parameters of a spatial point process. The method is an extension of Berman & Turner's (1992) device for maximizing the likelihoods of inhomogeneous spatial Poisson processes. For a very wide class of spatial point process models the likelihood is intractable, while the pseudolikelihood is known explicitly, except for the computation of an integral over the sampling region. Approximation of this integral by a finite sum in a special way yields an approximate pseudolikelihood which is formally equivalent to the (weighted) likelihood of a loglinear model with Poisson responses. This can be maximized using standard statistical software for generalized linear or additive models, provided the conditional intensity of the process takes an 'exponential family' form. Using this approach a wide variety of spatial point process models of Gibbs type can be fitted rapidly, incorporating spatial trends, interaction between points, dependence on spatial covariates, and mark information.