历史变局、国家兴衰与发展之路——三次千年变局叠加下的中国特色社会主义发展道路

每当先进的发展制度开始取代落后的发展制度时，整个世界格局就会进入重大的转换阶段。在中国五千年的发展历史中，有两次重大的历史变局完全改变了中国历史发展轨迹并深远地影响了当前中国的发展模式。新时代下的中国作为前两次历史变局影响的客体，曾经既是先进发展制度取代落后发展制度的受益者，也经历过作为落后发展制度主体而被先进发展制度冲击的过程。目前世界正处于第三次先进发展制度与落后发展制度交替的历史变局阶段，作为第三次重大历史变局的主体，在三次千年历史变局叠加的背景下，能否有效地认识、适应并改造利用前两次历史变局的经验与教训，构建系统性、科学性、可行性、领先性的中国特色社会主义制度，将决定中国在本次历史变局中能否顺利成为先进发展制度的主体从而实现民族复兴。     

Testing equality of two normal covariance matrices with monotone missing data

Abstract

The problem of testing equality of two multivariate normal covariance matrices is considered. Assuming that the incomplete data are of monotone pattern, a quantity similar to the Likelihood Ratio Test Statistic is proposed. A satisfactory approximation to the distribution of the quantity is derived. Hypothesis testing based on the approximate distribution is outlined. The merits of the test are investigated using Monte Carlo simulation. Monte Carlo studies indicate that the test is very satisfactory even for moderately small samples. The proposed methods are illustrated using an example.     

Measuring and Achieving Equity in Multiperiod Emergency Material Allocation

Emergency material allocation is an important part of postdisaster emergency logistics that is significant for improving rescue effectiveness and reducing disaster losses. However, the traditional single‐period allocation model often causes local surpluses or shortages and high cost, and prevents the system from achieving an equitable or optimal multiperiod allocation. To achieve equitable allocation of emergency materials in the case of serious shortages relative to the demand by victims, this article introduces a multiperiod model for allocation of emergency materials to multiple affected locations (using an exponential utility function to reflect the disutility loss due to material shortfalls), and illustrates the relationship between equity of allocations and the cost of emergency response. Finally, numerical examples are presented to demonstrate both the feasibility and the usefulness of the proposed model for achieving multiperiod equitable allocation of emergency material among multiple disaster locations. The results indicate that the introduction of a nonlinear utility function to reflect the disutility of large shortfalls can make the material allocation fairer, and minimize large losses due to shortfalls. We found that achieving equity has a significant but not unreasonable impact on emergency costs. We also illustrate that using differing utility functions for different types of materials adds an important dimension of flexibility.     

Blinded continuous monitoring in clinical trials with recurrent event endpoints

In studies with recurrent event endpoints, misspecified assumptions of event rates or dispersion can lead to underpowered trials or overexposure of patients. Specification of overdispersion is often a particular problem as it is usually not reported in clinical trial publications. Changing event rates over the years have been described for some diseases, adding to the uncertainty in planning. To mitigate the risks of inadequate sample sizes, internal pilot study designs have been proposed with a preference for blinded sample size reestimation procedures, as they generally do not affect the type I error rate and maintain trial integrity. Blinded sample size reestimation procedures are available for trials with recurrent events as endpoints. However, the variance in the reestimated sample size can be considerable in particular with early sample size reviews. Motivated by a randomized controlled trial in paediatric multiple sclerosis, a rare neurological condition in children, we apply the concept of blinded continuous monitoring of information, which is known to reduce the variance in the resulting sample size. Assuming negative binomial distributions for the counts of recurrent relapses, we derive information criteria and propose blinded continuous monitoring procedures. The operating characteristics of these are assessed in Monte Carlo trial simulations demonstrating favourable properties with regard to type I error rate, power, and stopping time, ie, sample size.     

Teaching technologies for immigrant children: an exploratory study of elementary school teachers in Russia*

ABSTRACT

Educational institutions are an important setting where psychological, pedagogical, sociocultural, and language adaptation of immigrant children occurs. A number of teaching strategies, practices, approaches, and methods have been described in the literature. In the Russian context, such strategies have been called ‘technologies’. The purpose of the present exploratory study was to describe teaching technologies used by teachers in Russia when working with immigrant students in elementary schools. Responses of forty-five elementary school teachers to open-ended questions describing technologies they use when teaching children with migration backgrounds were analyzed using content analysis. Findings suggest that Russian elementary school teachers used ethno-cultural group, communicative technologies, games, individualized instruction, and differentiated teaching. Many approaches mentioned can be used inclusively with groups of immigrant and non-immigrant students. Importantly, while teachers supplemented classroom instruction with additional Russian language lessons, none mentioned specific techniques for teaching Russian as a non-native language. These findings are discussed in relation to teaching strategies described in the international literature focused on migrant students. Finally, implications for further research are discussed.     

伸展构造背景下倾角资料的构造解释

系统总结了在伸展构造背景下，导致反映构造特征的地层倾角模式复杂化的多种因素。沉积相的不同、岩性变化、井眼状况和测井作业时间等多种因素都可能使地层倾角资料复杂化。进一步指出在拉张盆地中，进行倾角资料的构造解释，必须了解其构造样式的多样性和复杂性，解释存在的多解性。重点解剖了铲式断层在横剖面情况下，对于不同构造位置下的倾角模式。详细分析了一个倾角模式对应多种构造样式的倾角构造解释实例。倾角资料的构造解释应是综合解释，既要综合井筒的相关地质资料，又要综合测井与地质知识，还必须考虑综合地震资料。     

Random effects regression mixtures for analyzing infant habituation

Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.     

学术论文一稿多投的"诊"与"治"

一稿多投是学术界由来已久且难以医治的顽症。究其原因,主要是科研压力之下作者的投机心态、作者投稿经验的匮乏、稿件时效性的压力以及网上投稿的便捷与低成本等因素使然。一稿多投会造成编方人力资源的浪费,容易引发一稿多发,挤占宝贵的版面资源,引起版权纠纷,破坏学术诚信,扰乱科研秩序。要从加强制度建设、加大惩罚力度、利用高科技进行防范、健全监督机制、加强学术道德教育、提高编辑效率等方面,把"他律"与"自律"结合起来,惩防并举,标本兼治,多管齐下,齐抓共管,从根本上规范科研活动,根治一稿多投顽症。