论股份合作制对农村土地流转的现实意义

股份合作制对农村土地流转的现实意义有四个方面:一是有助于完善农民的土地产权制度;二是有助于实现农村经济的产业化;三是有助于农民实现规模经济;四是有助于建立和完善农村的新组织。     

关于我国学前教育领域内图画书研究文献的统计分析

图画书是一种适合儿童阅读的读物,我国当前对图画书的研究已经呈现多领域开展的态势,学前教育是其中的一个重要领域。用内容分析法对相关文献进行统计分析发现,学前教育领域内对图画书的研究呈现热度较高但水平相对不高且分布不均衡等特点,并对此提出了相关建议。     

小城镇发展与农村剩余劳动力转移

当前 ,我国农村剩余劳动力约在 2亿左右 ,农村剩余劳动力的转移 ,已经成为关系到改革开放和我国现代化建设全局的重大问题。通过分析农村剩余劳动力转移的现状及其制约因素 ,可以看出发展小城镇是解决农村剩余劳动力转移的根本途径。     

Do institutions really matter for saving among low-income households? A comparative approach

This study aims to examine the extent to which competing theories explain saving of low-income households in Individual Development Accounts (IDAs). Competing theories include the individual-oriented perspective, a social stratification perspective, and institutional saving theory. We use American Dream Demonstration (ADD) data collected at the Tulsa IDA program. Compared with the individual perspective and the social stratification perspective, institutional features explain a large part of the variance in saving outcomes measured by average monthly net deposit (AMND) and deposit frequency. Findings suggest that institutional structures encouraging low-income households to save may contribute to more inclusive asset-based policy.     

Determining species specific nightly bat activity in sites with varying urban intensity

Time of peak bat activity during the night differs among bat species due to temperature, prey availability, habitat availability, and/or interactions between species. Habitat availability is altered in urban areas, which may affect insect prey availability and interspecies interactions. Our objectives were to use mobile acoustic monitoring to determine when bat species were active in a single night in urban and nonurban sites and if nightly bat activity patterns differed in urban versus nonurban sites. Bat echolocation call sequences were recorded using Anabat acoustic detectors while driving transects through the night at five sites (three “urban” and two “nonurban”) located in the Piedmont region of north-central North Carolina from May through August 2016. Transects were driven three times per night starting 45 min, 180 min, and 300 min after sunset. Recorded echolocation call sequences were analyzed manually using AnalookW and automatically using Bat Call Identification and Echoclass software. Total bat activity was not different between urban and nonurban sites. However, total bat activity was lower later in the night in urban sites, but stayed the same in nonurban sites. Species specifically, there were more Eptesicus fuscus, Lasionycteris noctivagans, and Tadarida brasiliensis call sequences and fewer Lasiurus borealis, Nycticeius humeralis, and Perimyotis subflavus call sequences in urban sites than nonurban sites. There were also fewer E. fuscus, L. noctivagans, and N. humeralis call sequences later in the night in both urban and nonurban sites. Only Lasiurus borealis activity in urban sites later in the night reduced and L. borealis activity in nonurban sites remained at the same. These results suggest that bats in urban areas partition time differently, which is important to consider for urban conservation efforts and planning.     

经济景气指标与实际GDP增长率的混频预测

文章通过构建月度景气指标与季度实际GDP增长率之间的混频动态向量自回归模型,并采用期望最大值算法和卡尔曼滤波来实现混频数据和缺失数据的估计和迭代预测.大量月度景气指标的MFVAR模型的伪实时数据的多步滚动迭代样本外预测结果表明:虽然不同类别的月度景气变量在不同预测期的预测结果存在一定的差异,但实时预报、短期预测,以及组合预测结果均表明混频动态向量自回归预测模型对我国季度实际GDP增长率的实时预报和短期预测具有精确性、有效性与适用性.     

A Bayesian sequential design with binary outcome

Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha‐spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha‐spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.     

基于全球商品流量表的中国大陆贸易影响力测算

文章利用国际货币基金组织(IMF)公布的各国(地区)进出口数据,编制了2015年全球商品流量表(G-CFM),描绘了国家(地区)间商品贸易网络关系,采用网络分析的方法对全球商品贸易格局进行了分析,发现了在全球商品贸易中以美、中、德为中心,世界各国紧密交织的网络特征,最后用投入产出方法分析了中国大陆的贸易影响力,测算了中国大陆进出口贸易对不同国家(地区)以及对全球的影响.     

Examining identity development among gay men of color

Within the past few decades, there has been an explosion of articles examining “gay identity.” Yet, much of this work continues to center on the experiences of gay White men or fail to adequately examine the process of identity development, even when “identity” is central to the discussion. This review outlines 4 theoretical perspectives used to explore gay men of color and identity development. Taken together, these 4 perspectives can offer a rich opportunity to explore the ways that gay men of color come to develop an identity that simultaneously addresses their racial and sexual identities. I argue that examining identity development among gay men of color can help sociology better understand the identity process and provide new insights into examining intersectionality by demonstrating that identities are not only intersectional but also contextual.     

Estimation of variance in bivariate normal distribution after the preliminary test of homogeneity

A preliminary test estimator of variance in the bivariate normal distribution is proposed after the Pitman–Morgan test of homogeneity of two variances. The bias and mean square error of the estimator are derived. The relative efficiency (RE) of the preliminary test estimator is studied. Computations and 3D graphs of RE for different parameters are analyzed. In order to get the maximum RE, recommendations of the significance level for the preliminary test are given for various sample sizes by using the max–min criterion.