多功能实时时钟

早期RTC产品实质是一个带有计算机通讯口的分频器。它通过对晶振所产生的振荡频率分频和累加,得到年、月、日、时、分、秒等时间信息并通过计算机通讯口送入处理器处理。新一代RTC,它采用特殊CMOS工艺;功耗大为降低,典型值约0.5μA以下,更加入了复合功能,如低电压检测,主备用电池切换功能,抗印制板漏电功能,且本身封装更小(高度0.85mm,面积仅为2mm*2mm),如RICOH公司的代表产品R2051。它的研究方法和相关理论也较以前有许多不同。     

Childhood family structure and young adult behaviors

This paper examines a wide variety of forms, and full histories, of family structure to test existing theories of family influences and identify needs for new theories. The focus is on links between childhood family structure and both completed schooling and risk of a nonmarital birth. Using a 27-year span of panel (PSID) data for U.S. children, we find that: (a) change is stressful, (b) timing during childhood is relevant, (c) adults other than parents are important, and (d) two more recently studied family structures (mother-with-grandparent(s) and mother-with-stepfather) do not fit the molds of existing theories. The findings suggest that new theories should consider allocation of resources and reasons people group into family structures. Received: 11 September 1998/Accepted: 27 March 2000     

Intention to emigrate in transition countries: the case of Albania

We analyse the profile of potential emigrants from Albania using data from the Central and Eastern Europe Eurobarometer in 1992. Respondents were asked to rate on a four-point scale the likelihood that they would go to live in Western Europe. Our results show that intention to emigrate is correlated positively with males, education and certain occupations, and negatively with age. There is little relation between emigration and income. Those who support the introduction of a free market in Albania are also more likely to emigrate than those who do not. Received: 24 August 1998/Accepted: 17 April 2000     

《寻金者》中自然和空间意象的生态隐喻

西方现代文明语境下物质主义导致的内心空虚和对人类永恒精神家园的追寻,是法国生态作家勒克莱齐奥始终关注的主题。他在小说《寻金者》中通过“寻金”主题的双重隐喻,表达了作家一贯对西方现代文明和物质主义的批判;对自然元素和空间意象的诗意描绘,以及对异域土著文明生态价值的关注,赋予了作家笔下的想象空间以神话般的象征色彩和深刻的生态隐喻意义,表达了作家非西方中心主义的文明观和对人类真正宝藏——人与自然和谐家园的追求。     

在全面建设小康社会中大力发展高等教育

全面建设小康社会 ,必须大力发展高等教育。首先 ,全社会要充分认识高等教育在知识经济时代的先导作用 ;其次 ,高等教育要深化改革 ,使办学主体跟上时代发展的步伐 ;再次 ,要强化教育创新 ,使培养对象成为适应全面建设小康社会需要的人才。     

Mr.J.F.McLennan's Study of Polyandry

John F.McLennan is well known for introducing the terms of “exogamy” and “en-dogamy” in Primitive Marriage:An Inquiry into the Origins of the Form of Capture in Marriage Ceremo-nies(1865) .In this book...     

Noninformative priors for linear combinations of normal means with unequal variances

For normal populations with unequal variances, we develop matching priors and reference priors for a linear combination of the means. Here, we find three second-order matching priors: a highest posterior density (HPD) matching prior, a cumulative distribution function (CDF) matching prior, and a likelihood ratio (LR) matching prior. Furthermore, we show that the reference priors are all first-order matching priors, but that they do not satisfy the second-order matching criterion that establishes the symmetry and the unimodality of the posterior under the developed priors. The results of a simulation indicate that the second-order matching prior outperforms the reference priors in terms of matching the target coverage probabilities, in a frequentist sense. Finally, we compare the Bayesian credible intervals based on the developed priors with the confidence intervals derived from real data.     

Deletion residuals in the detection of heterogeneity of variances in linear regression

The heterogeneity of error variance often causes a huge interpretive problem in linear regression analysis. Before taking any remedial measures we first need to detect this problem. A large number of diagnostic plots are now available in the literature for detecting heteroscedasticity of error variances. Among them the ‘residuals’ and ‘fits’ (R–F) plot is very popular and commonly used. In the R–F plot residuals are plotted against the fitted responses, where both these components are obtained using the ordinary least squares (OLS) method. It is now evident that the OLS fits and residuals suffer a huge setback in the presence of unusual observations and hence the R–F plot may not exhibit the real scenario. The deletion residuals based on a data set free from all unusual cases should estimate the true errors in a better way than the OLS residuals. In this paper we propose ‘deletion residuals’ and the ‘deletion fits’ (DR–DF) plot for the detection of the heterogeneity of error variances in a linear regression model to get a more convincing and reliable graphical display. Examples show that this plot locates unusual observations more clearly than the R–F plot. The advantage of using deletion residuals in the detection of heteroscedasticity of error variance is investigated through Monte Carlo simulations under a variety of situations.     

An F Approximation to the Distribution of a Linear Combination of Chi-squared Variables.

A three-parameter F approximation to the distribution of a positive linear combination of central chi-squared variables is described. It is about as easy to implement as the Satterthwaite-Welsh and Hall-Buckley-Eagleson approximations. Some reassuring properties of the F approximation are derived, and numerical results are presented. The numerical results indicate that the new approximation is superior to the Satterthwaite approximation and, for some purposes, better than the Hall-Buckley-Eagleson approximation. It is not quite as good as the Gamma-Weibull approximation due to Solomon and Stephens, but is easier to implement because iterative methods are not required.     

Comparing Two Population Means and Variances: A Parametric Robust Way

Abstract

This article introduces a parametric robust way of comparing two population means and two population variances. With large samples the comparison of two means, under model misspecification, is lesser a problem, for, the validity of inference is protected by the central limit theorem. However, the assumption of normality is generally required, so that the inference for the ratio of two variances can be carried out by the familiar F statistic. A parametric robust approach that is insensitive to the distributional assumption will be proposed here. More specifically, it will be demonstrated that the normal likelihood function can be adjusted for asymptotically valid inferences for all underlying distributions with finite fourth moments. The normal likelihood function, on the other hand, is itself robust for the comparison of two means so that no adjustment is needed.