“当/在S还是X的时候”结构新探

本文分为三个部分。第一部分考察"当/在S还是X的时候"的结构和功能;第二部分分析简缩形式"还是X的时候";第三部分探讨常见组合"当/在S还是X的时候,S'就……"的意义与语用特点。最后是本文的小结。     

Child‐Care Usage and Mother‐Infant “Quality Time”

Mothers' time‐use patterns were compared in families in which infants spent more than 30 hours per week in child care (In‐Care group; n= 143) versus 0 hours per week (At‐Home group; n= 183) from birth to 6 months of age. In‐Care group mothers spent about 12 fewer hours per week interacting with their infants, for about 32% less time; fathers of these infants were more involved in caregiving. The groups did not differ in the quality of mother‐infant interaction. In the In‐Care group, quantity of interaction was related to greater separation anxiety and concerns about effects of maternal employment. Time‐use data were not related to child outcomes at 15 months of age. Results suggest that the effect of extensive time spent apart on the quantity and quality of mother‐infant interaction may be smaller than anticipated.     

Physiologically Based Liver Modeling and Risk Assessment

Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments.     

论近代中国产业革命被窒息的原因--一个必须遵循先进生产力发展要求的历史实例

近代科学技术与民族棉纺织业私人资本结合是东方型产业革命兴起的直接导因.洋务运动使近代中国具备了产业革命兴起的可能性;但由于晚清政府不能代表当时中国先进生产力的发展要求,造成近代中国棉纺织业的发展走的是一条技术与资本相分离的道路,致使近代中国产业革命被窒息.     

Missing data and forecasting in multivariate time series: An application of the common components dynamic linear model

Summary The paper deals with missing data and forecasting problems in multivariate time series making use of the Common Components Dynamic Linear Model (DLMCC), presented in Quintana (1985), and West and Harrison (1989). Some results are presented and discussed: exploiting the correlation between series, estimated by the DLMCC, the paper shows as it is possible to update state vector posterior distributions for the unobserved series. This is realized on the base of the updating of the observed series state vectors, for which the usual Kalman filter equations can be applied. An application concerning some Italian private consumption series provides an example of the model capabilities.     

跨文化交际中的时空观念差异

不同文化背景的人,由于受不同文化传统的影响,其思维方式不同,在人际交往中的时间观念(如时间顺序排列、时间取向、遵守时间的态度)和空间观念(如对体距的认识、对个人领地的态度等)也存在差异。这些差异往往容易被人们忽视,从而影响交际的正常进行,甚至导致交际的失败。因此,在交往中我们应该正确对待文化差异,自觉排除文化差异的干扰。     

Bayesian analysis of directed graphs data with applications to social networks

Summary.  A fully Bayesian analysis of directed graphs, with particular emphasis on applica- tions in social networks, is explored. The model is capable of incorporating the effects of covariates, within and between block ties and multiple responses. Inference is straightforward by using software that is based on Markov chain Monte Carlo methods. Examples are provided which highlight the variety of data sets that can be entertained and the ease with which they can be analysed.     

Sampling Returns for Realized Variance Calculations: Tick Time or Transaction Time?

This article introduces a new model for transaction prices in the presence of market microstructure noise in order to study the properties of the price process on two different time scales, namely, transaction time where prices are sampled with every transaction and tick time where prices are sampled with every price change. Both sampling schemes have been used in the literature on realized variance, but a formal investigation into their properties has been lacking. Our empirical and theoretical results indicate that the return dynamics in transaction time are very different from those in tick time and the choice of sampling scheme can therefore have an important impact on the properties of realized variance. For RV we find that tick time sampling is superior to transaction time sampling in terms of mean-squared-error, especially when the level of noise, number of ticks, or the arrival frequency of efficient price moves is low. Importantly, we show that while the microstructure noise may appear close to IID in transaction time, in tick time it is highly dependent. As a result, bias correction procedures that rely on the noise being independent, can fail in tick time and are better implemented in transaction time.     

时间如何前进——进化论随笔

中国古代"与时偕行"、"与时俱化"的观念,以取法天地四时的运行为基准,是一种四时循环论的变化观.我党提出的"与时俱进"思想的含义,是随着时代的前进而前进,和随着时代的变化而变化,体现了鲜明的时代创新精神,它的哲学基础是科学进化论.这一特征在语词上通过一个"进"字表达出来.虽然"与时俱进"和"与时俱化"只有一字之差,却体现了本质的超越.同时,这一表述通过对中国古代<易经>、<庄子>等经典的吸收,丰富了自身的思想内涵,也建立,了联接传统与现代的一道桥梁.当然,由于现代时间观念的一维性质,使得人们在批驳"直线进化论"的同时,易于陷入"时间进化论",而时间进化论实际上也是一种直线进化论,这也是需要警醒的.     

New imperfect rankings models for ranked set sampling

Ranked set sampling is a sampling approach that leads to improved statistical inference in situations where the units to be sampled can be ranked relative to each other prior to formal measurement. This ranking may be done either by subjective judgment or according to an auxiliary variable, and it need not be completely accurate. In fact, results in the literature have shown that no matter how poor the quality of the ranking, procedures based on ranked set sampling tend to be at least as efficient as procedures based on simple random sampling. However, efforts to quantify the gains in efficiency for ranked set sampling procedures have been hampered by a shortage of available models for imperfect rankings. In this paper, we introduce a new class of models for imperfect rankings, and we provide a rigorous proof that essentially any reasonable model for imperfect rankings is a limit of models in this class. We then describe a specific, easily applied method for selecting an appropriate imperfect rankings model from the class.