Approximations and Heuristics for the "Cause-Modified" Life Table

Life-table analysis can help to gauge the lifetime impacts that accrue from modifications to (age-specific) baseline mortality. Modifications of interest include those stemming from risk-factor-related exposures or from interventions. The specific algorithm used in these analyses can be called a cause-modified life table (a generalization of the cause-deleted life table). The author presents an approach for approximating that algorithm and uses it to obtain remarkably simplified expressions for approximating three indices of common interest: life-years lost (LYL), excess lifetime risk ratio (ELRR), and risk of exposure-induced death (REID). These efforts are restricted to the special case of multiplicative increases to baseline mortality (modeled as an excess rate ratio, ERR). The simplified expressions effectively "break open" what is often treated as a "black-box" calculation. Several insights result. For a practical range of risk factor impacts (ERRs), each index can be related to the ERR as a function of a baseline summary statistic and a "characteristic number" specific to the population and cause of interest. Conveniently, those numbers help form "rules of thumb" for translating among the three indices and suggest heuristics for extrapolating indices across populations and causes of death.     

人生、哲学与艺术的完美统一──《庄子》散文的文学特质与价值

《庄子》散文以其奇特瑰丽的想象,构筑了一个超脱于生世的理想世界,在中国文学史上具有独特的审美价值,庄子的哲学思想及对人生的理性思考都蕴含在他精心构建的散文意象中,并创立了“寓言”这一文学样式。其美学思想、艺术气质亦对后世文艺批评和文艺创作有深广的影响。     

动态投入产出表在城市经济转型评价中的运用

在对现有城市经济转型评价相关研究进行综述的基础上,指出在城市经济转型评价中引入投入产出技术的重要性。研究结论是:建立基本的投入产出表,可以帮助分析城市经济转型中产业结构调整优化的情况;建立经济、资源、环境投入产出表,可以揭示城市经济转型中三者之间的协调关系;建立扩展的投入产出表,可以分析城市经济转型对民生和社会指标的影响。     

Marginal asymmetry model for square contingency tables with ordered categories

For the analysis of square contingency tables with ordered categories, this paper proposes a model which indicates the structure of marginal asymmetry. The model states that the absolute values of logarithm of ratio of the cumulative probability that an observation will fall in row category i or below and column category i+1 or above to the corresponding cumulative probability that the observation falls in column category i or below and row category i+1 or above are constant for every i. We deal with the estimation problem for the model parameter and goodness-of-fit tests. Also we discuss the relationships between the model and a measure which represents the degree of departure from marginal homogeneity. Examples are given.     

少儿乒乓球运动员选材上应注意的几个方面

从少儿的年龄、神经类型、心理、专项素质、身体素质几个方面进行探讨 ,旨在探索对少儿乒乓球运动员选材的科学性、实用性 ,以提高运动员成材率     

关于自然科学各专类复分表中子目号前冠“0”问题探讨

对自然科学各类所列专类复分表子目号前统一冠“0”问题进行了探讨，进一步阐述仿复分加“0”目的、掌握加“0”方法、避免加“0”差错，主张统一设置专类复分表中的子目类号，将双位数字编码中无用的“0”删掉。     

A flexible marginal modelling strategy for non-monotone missing data

Summary.  Much research has been devoted to modelling strategies for longitudinal data with missingness, recently especially within the missingness not at random context. In this paper, the relatively unexplored but practically highly relevant domain of non-monotone missingness with multivariate ordinal responses is broached. For this, a dedicated version of the multivariate Dale model is formulated. Furthermore, we also assess the sensitivity of these models to their assumptions, by using the technique of global influence.     

Identifying rational distributed lag models using a joint test applied to the corner table

Often a distributed lag response pattern can be usefully represented in rational polynomial form. When the impulse response function decays, the corner table may be useful for model identification if appropriate statistical tests may be done. One or more joint tests are called for since use of the corner table involves studying groups of its elements. We consider an asymptotic x2 statistic that permits joint tests. We report simulation results showing that the distribution of this statistic follows the x ² distribution, for certain sample sizes and degrees of freedom, well enough to be useful in practice. With two data sets we illustrate how this statistic can be a useful aid when using the corner table.     

DHT网络规模估计算法的定量分析与设计

为准确而高效地估计分布式哈希表(DHT)的网络规模,提出一种基于平均间距的估计算法。该算法利用节点之间的间距服从指数分布这一特性,通过测量平均间距长度估计网络规模。从最简单情况入手,逐渐增加估计的间距个数,定量分析了网络规模估计值的概率分布和置信区间。根据分析,如果采用多条间距估计网络规模,估计值将服从参数为(k,k)的伽马分布的尾分布。最后,仿真试验验证了算法的有效性与分析的正确性。     

Alternative modeling techniques for the quantal response data in mixture experiments

Mixture experiments are commonly encountered in many fields including chemical, pharmaceutical and consumer product industries. Due to their wide applications, mixture experiments, a special study of response surface methodology, have been given greater attention in both model building and determination of designs compared with other experimental studies. In this paper, some new approaches are suggested on model building and selection for the analysis of the data in mixture experiments by using a special generalized linear models, logistic regression model, proposed by Chen et al. [7]. Generally, the special mixture models, which do not have a constant term, are highly affected by collinearity in modeling the mixture experiments. For this reason, in order to alleviate the undesired effects of collinearity in the analysis of mixture experiments with logistic regression, a new mixture model is defined with an alternative ratio variable. The deviance analysis table is given for standard mixture polynomial models defined by transformations and special mixture models used as linear predictors. The effects of components on the response in the restricted experimental region are given by using an alternative representation of Cox's direction approach. In addition, odds ratio and the confidence intervals of odds ratio are identified according to the chosen reference and control groups. To compare the suggested models, some model selection criteria, graphical odds ratio and the confidence intervals of the odds ratio are used. The advantage of the suggested approaches is illustrated on tumor incidence data set.