Detecting discontinuities in nonparametric regression curves and surfaces

The existence of a discontinuity in a regression function can be inferred by comparing regression estimates based on the data lying on different sides of a point of interest. This idea has been used in earlier research by Hall and Titterington (1992), Müller (1992) and later authors. The use of nonparametric regression allows this to be done without assuming linear or other parametric forms for the continuous part of the underlying regression function. The focus of the present paper is on assessing the evidence for the presence of a discontinuity within a regression function through examination of the standardised differences of ‘left’ and ‘right’ estimators at a variety of covariate values. The calculations for the test are carried out through distributional results on quadratic forms. A graphical method in the form of a reference band to highlight the sources of the evidence for discontinuities is proposed. The methods are also developed for the two covariate case where there are additional issues associated with the presence of a jump location curve. Methods for estimating this curve are also developed. All the techniques, for the one and two covariate situations, are illustrated through applications.     

学分绩点制学籍管理的探讨

文章分析了学分绩点制学籍管理的特点，对学分绩点制学籍管理方法及其实施措施进行了研究，提出了一套适合工科院校特点的、行之有效的学分绩点制学籍管理制度。     

The efficient estimation of tail probabilities for extremes of moving average processes using conditional simulation

This paper describes a conditional simulation technique which can be used to estimate probabilities associated with the distribution of the maximum of a real-valued process which can be written in the form of a moving average. The class of processes to which the technique applies includes non-stationary and spatial processes, and autoregressive processes. The technique is shown to achieve a considerable variance reduction compared with the obvious simulation-based estimator, particularly for estimating small upper-tail probabilities.     

一类非线性二阶微分系统两点边值问题

给出了一类非线性二阶微分系统两点边值共振问题可解的一组充分条件.     

Assessing Crew Response Probability for a Sequence of Actions with an Overall Time Constraint

The following situation has been considered: during an accident sequence, a crew has to do a proper set of actions within a finite time window in order to achieve a specific goal. The operator actions are considered independent, they are lined up in series, and a single failure leads to mission failure. This paper proposes a general methodology for assessing the crew response (or success) probability, through a convolution integral formulation. This method is general and can be applied to any response probability model; an application to the Human Cognitive Reliability model is given.     

Score test of homogeneity for survival data

If follow-up is made for subjects which are grouped into units, such as familial or spatial units then it may be interesting to test whether the groups are homogeneous (or independent for given explanatory variables). The effect of the groups is modelled as random and we consider a frailty proportional hazards model which allows to adjust for explanatory variables. We derive the score test of homogeneity from the marginal partial likelihood and it turns out to be the sum of a pairwise correlation term of martingale residuals and an overdispersion term. In the particular case where the sizes of the groups are equal to one, this statistic can be used for testing overdispersion. The asymptotic variance of this statistic is derived using counting process arguments. An extension to the case of several strata is given. The resulting test is computationally simple; its use is illustrated using both simulated and real data. In addition a decomposition of the score statistic is proposed as a sum of a pairwise correlation term and an overdispersion term. The pairwise correlation term can be used for constructing a statistic more robust to departure from the proportional hazard model, and the overdispesion term for constructing a test of fit of the proportional hazard model.     

同姓名现象的症结与改革我国姓名制度的思路

我国汉民族人口中的同姓名现象越来越严重 ,其根本原因是中国的姓氏过于庞大。由于汉字姓氏中 ,绝大多数是单姓 ,而常用汉字的数量有限 ,这就必然限制了姓氏的数量。因此 ,中国人的同姓名问题的症结 ,与其说在于单名 ,不如说在于单姓。为了摆脱这种两难的境地 ,就要考虑增加双字姓甚至多字姓 ,通过变换字的排列组合来创造姓氏 ,而创造姓氏的途径则是姓氏分流 ,同时 ,通过改变姓名结构 ,区别构件功能 ,改革我国汉民族的姓名制度。     

我国房地产业可持续发展的目标及对策分析

房地产业是国民经济的基础产业 ,也是国民经济新的增长点。随着经济体制改革的不断深入 ,房地产业能否持续发展 ,将直接影响到整个国民经济和社会的可持续发展 ,因此 ,坚持可持续发展应成为我国房地产业的战略选择。     

以虚粒子为特征的阴性物质能量的释放--人类可利用的新能源之探索

从我们人类所在的四维时空的视点观察,宇宙的边界就是阳性物质世界三维空间弯曲的极限.以虚粒子为特征的阴性物质充盈在三维空间,直至宇宙的边界;但是它并不占有这个空间和边界.爱因斯坦相对论公式虽然具有普遍的意义,但是用它来解释四维以上多维时空以虚粒子为特征的阴性物质时,却显得无能为力,甚至不能说明任何问题--这里正是新的科学的起点和发祥地.以虚粒子为特征的阴性物质蕴含着宇宙间总能量的二分之一,并且携带着宇宙和人类的所有信息和密码.探索以虚粒子为特征的阴性物质能量释放的条件,是解决人类可利用的新能源的当务之急.     

可分Banach空间中的微分包含

在可分的Ｂａｎａｃｈ空间中研究微分包含ｘ′∈Ｆ（ｔ，ｘ）解的存在性，对Ｋｉｓｉｅｌｅｗｉｃｚ的结果作了改进．