高校体育专业乒乓球专项课互动式教学模式的运用研究*

通过互动式教学模式运用,发现互动式教学模式可以加强教师与学生之间的互动性交流,使学生在思维能力、知识理解和技能掌握方面都在达到一个新的教学成果,并且通过二者的相互作用,能使当前高校体育专业乒乓球专项课的教学方式和教学环境不断的在双方的互动中进行改进与创新,将传统的体育专业术科课程单向传输的教学模式转变为教师与学生的双向沟通和互动,实现提高教学质量的目的。     

Life table estimator revisited

We explore the standard life table (actuarial) estimator for grouped right-censored survival data and its extensions in order to consider its relationship with the Kaplan–Meier estimator, and to investigate the critical properties of the extended life table estimators (ELTEs). We discuss certain conditions for the ELTE to be consistent and develop a characterization of the standard life table estimator using the consistency property under any choice of at least two observation times of a finite interval. We also perform a comparative analysis of the ELTEs with the corresponding maximum likelihood estimators for grouped right-censored survival data.     

Interventions Targeting Deep Tissue Lymph Nodes May Not Effectively Reduce the Risk of Salmonellosis from Ground Pork Consumption: A Quantitative Microbial Risk Assessment

The inclusion of deep tissue lymph nodes (DTLNs) or nonvisceral lymph nodes contaminated with Salmonella in wholesale fresh ground pork (WFGP) production may pose risks to public health. To assess the relative contribution of DTLNs to human salmonellosis occurrence associated with ground pork consumption and to investigate potential critical control points in the slaughter‐to‐table continuum for the control of human salmonellosis in the United States, a quantitative microbial risk assessment (QMRA) model was established. The model predicted an average of 45 cases of salmonellosis (95% CI = [19, 71]) per 100,000 Americans annually due to WFGP consumption. Sensitivity analysis of all stochastic input variables showed that cooking temperature was the most influential parameter for reducing salmonellosis cases associated with WFGP meals, followed by storage temperature and Salmonella concentration on contaminated carcass surface before fabrication. The input variables were grouped to represent three main factors along the slaughter‐to‐table chain influencing Salmonella doses ingested via WFGP meals: DTLN‐related factors, factors at processing other than DTLNs, and consumer‐related factors. The evaluation of the impact of each group of factors by second‐order Monte Carlo simulation showed that DTLN‐related factors had the lowest impact on the risk estimate among the three groups of factors. These findings indicate that interventions to reduce Salmonella contamination in DTLNs or to remove DTLNs from WFGP products may be less critical for reducing human infections attributable to ground pork than improving consumers’ cooking habits or interventions of carcass decontamination at processing.     

Efficient Bayesian analysis of multivariate aggregate choices

In estimating individual choice behaviour using multivariate aggregate choice data, the method of data augmentation requires the imputation of individual choices given their partial sums. This article proposes and develops an efficient procedure of simulating multivariate individual choices given their aggregate sums, capitalizing on a sequence of auxiliary distributions. In this framework, a joint distribution of multiple binary vectors given their sums is approximated as a sequence of conditional Bernoulli distributions. The proposed approach is evaluated through a simulation study and is applied to a political science study.     

The exact unconditional z-pooled test for equality of two binomial probabilities: optimal choice of the Berger and Boos confidence coefficient

Exact unconditional tests for comparing two binomial probabilities are generally more powerful than conditional tests like Fisher's exact test. Their power can be further increased by the Berger and Boos confidence interval method, where a p-value is found by restricting the common binomial probability under H ₀ to a 1?γ confidence interval. We studied the average test power for the exact unconditional z-pooled test for a wide range of cases with balanced and unbalanced sample sizes, and significance levels 0.05 and 0.01. The detailed results are available online on the web. Among the values 10^?3, 10^?4, …, 10^?10, the value γ=10^?4 gave the highest power, or close to the highest power, in all the cases we looked at, and can be given as a general recommendation as an optimal γ.     

社会核算矩阵与国民经济账户、投入产出表的关系研究

社会核算矩阵(SAM)刻画了社会经济主体间通过要素市场、商品市场而发生的交易和收支转移活动。结合国民经济核算理论研究了国民经济账户、投入产出(IO)表与SAM之间的关系,结果表明:SAM是以矩阵形式表示的国民经济核算体系(SNA)账户,SAM以复式记账的核算原则和矩阵的形式提供了国民经济的另外一种核算方式;IO表是编制SAM的重要数据来源。     

Stochastic search variable selection for log-linear models

We develop a Markov chain Monte Carlo algorithm, based on ‘stochastic search variable selection’ (George and McCuUoch, 1993), for identifying promising log-linear models. The method may be used in the analysis of multi-way contingency tables where the set of plausible models is very large.     

Quasi-asymmetry model for square tables with nominal categories

For an R×R square contingency table with nominal categories, the present paper proposes a model which indicates that the absolute values of log odds of the odds ratio for rows i and j and columns j and R to the corresponding symmetric odds ratio for rows j and R and columns i and j are constant for every i<j<R. The model is an extension of the quasi-symmetry model and states a structure of asymmetry of odds ratios. An example is given.     

乒乓球台内反手侧拉技术分析

乒乓球是一项技术性很强的竞技体育项目,随着该项运动的发展,新的技术理念不断涌现,台内反手侧拉就是近年来出现的新技术之一.反手侧拉台内小球的特点就是在有限的时间、空间内,尽可能延长挥拍路线,用摩擦击球的方法,提高球的命中率和旋转性,从而为争取主动创造机会.反手侧拉球技术的掌握除了必须明确其动作原理外,还应提高弧形摩擦球的能力,也要加强训练才能运用自如.     

A practical method to calculate probabilities: illustrative example from the electronic industry business

The real-life environment is made of probabilistic data by nature and the ability to make decisions based on probabilities is crucial in the business world. It is common to have a set of data and the need of calculating the probability of taking a value greater or less than a specific value. It is also common in many companies the unavailability of a statistical software or a specialized professional in statistics. The purpose of this paper is to present a practical and simple method to calculate probabilities from normal or non-normal distributed data set and illustrate it with an application from the electronic industry. The method does not demand statistical knowledge from the user; there is no need of normality assumptions, goodness test or transformations. The proposed method is easy to implement, robust and the experiments have evidenced its quality. The technique is validated with a large variety of instances and compared with the well-known Johnson system of distributions.