Variable selection models based on multiple imputation with an application for predicting median effective dose and maximum effect

The statistical methods for variable selection and prediction could be challenging when missing covariates exist. Although multiple imputation (MI) is a universally accepted technique for solving missing data problem, how to combine the MI results for variable selection is not quite clear, because different imputations may result in different selections. The widely applied variable selection methods include the sparse partial least-squares (SPLS) method and the penalized least-squares method, e.g. the elastic net (ENet) method. In this paper, we propose an MI-based weighted elastic net (MI-WENet) method that is based on stacked MI data and a weighting scheme for each observation in the stacked data set. In the MI-WENet method, MI accounts for sampling and imputation uncertainty for missing values, and the weight accounts for the observed information. Extensive numerical simulations are carried out to compare the proposed MI-WENet method with the other competing alternatives, such as the SPLS and ENet. In addition, we applied the MI-WENet method to examine the predictor variables for the endothelial function that can be characterized by median effective dose (ED50) and maximum effect (Emax) in an ex-vivo phenylephrine-induced extension and acetylcholine-induced relaxation experiment.     

建设项目循环成本与收益形成机理及评价模型

建设项目是我国发展循环经济的重要载体,然而现有的建设项目可行性评估缺乏对循环经济能力的评价,因此不能反映项目的循环经济能力和收益水平。对此,应用循环经济理论,探讨建设项目循环成本与收益的特征并识别其构成要素,据此对传统的费用效益比和经济净现值评价方法进行改进,建立循环费用效益比评价和循环经济净现值评价两种针对循环经济项目的评价模型。这两个模型可作为评价指标用于建设项目前期评估和建设项目比较选择。     

大系统观下降解率与均衡价格的联络——资源有界引致的市场逻辑

资源稀缺下的市场定价,由于要素循环是必需的,故市场价格在受上变量和侧变量影响的同时,还受下变量的影响。通过构造劳动力—功能空间图,把表征为下变量的未来因子引入对均衡价格的决定中,并认为当期均衡价格由"未来商品供给和当前商品供给生成的总供给"与"未来商品需求和当前商品需求生成的总需求"联合决定,由此引入影响未来供给的降解率因子。因此,资源稀缺社会里,社会机制的设计和社会法则的提取应放在更大系统内探究。     

航运高端服务业的生成和演化:全球价值网视角

在上海建设国际航运中心的过程中,航运高端服务业的发展十分关键,很大程度上代表着航运业的全球竞争力。运用价值网观点,从制造业价值网、服务业价值网出发,提出基于价值网的基本分析框架,讨论航运高端服务业的产生动因,得到三个基本推断。     

青少年网瘾家庭成因分析及干预研究

青少年网瘾已经成为当前一个严重的社会问题,其发生与家庭有一定的关系。其表现为一是父母缺乏对青少年期孩子心理特点的了解,关心不够;二是父母的引导教育不相一致,形不成合力。要实施青少年网瘾的家庭干预,首先要实现亲子之间的良好沟通,并注意给予孩子足够的关爱和支持,在积极肯定孩子在家庭生活中权利和责任的同时,努力培养孩子的＂网商＂。     

喷树增产耐贮剂对沙糖桔树上及采后的保鲜效果

于沙糖桔果实转色期喷施＂喷树增产耐贮剂＂,可提高采前保果率、总糖、可溶性固形物和谷胱甘肽的含量,显著降低因干冷和湿冷引起的伤果和落果率.该处理可显著减少采后贮藏期总糖、可溶性固形物和水分的损失,减少烂果率,有助于维持果品的产量和质量.     

The Bayesian elastic net regression

A Bayesian elastic net approach is presented for variable selection and coefficient estimation in linear regression models. A simple Gibbs sampling algorithm was developed for posterior inference using a location-scale mixture representation of the Bayesian elastic net prior for the regression coefficients. The penalty parameters are chosen through an empirical method that maximizes the data marginal likelihood. Both simulated and real data examples show that the proposed method performs well in comparison to the other approaches.     

Welfare residualism: a comparative study of the Basic Livelihood Security systems in China and South Korea

Gao Q, Yoo J, Yang S‐M, Zhai F. Welfare residualism: a comparative study of the Basic Livelihood Security systems in China and South Korea Int J Soc Welfare 2011: 20: 113–124 © 2010 The Author(s), International Journal of Social Welfare © 2010 Blackwell Publishing Ltd and International Journal of Social Welfare. In this article, the Basic Livelihood Security (BLS) systems of China and South Korea are compared. The purpose of BLS is to provide a safety net for poor families, particularly the unemployed and the retired who were hard‐hit by recent economic reforms and crises. A common characteristic of the two systems is residual welfare marked by strict eligibility rules and limited coverage. Both systems are subordinate to the primary goal of economic growth and therefore only compensate for the very disadvantaged left behind by market competition. Neither system is particularly effective in achieving its original antipoverty goals. However, South Korea's provision of self‐support programs to supplement cash transfers has helped individuals to move from welfare to work, and thus has implications for China's BLS system. Both countries need to put more emphasis on equity and social justice in their ongoing reforms and expansions of BLS.     

“和”文明起源考（语音篇）

从语源学、音韵学、文化学的角度推本穷源,“和”文明的起源应始于古人见到众多可以饱腹的禾谷而惊叹的“夥”;久而久之,定名为“禾”;因为“求禾”而有“ ”;禾谷丰收,人们会认为是求禾行为得到了上天的回应,因而产生了“应和”义的“和”;又因“禾以其调和人之性命”,“其米多而沃,食之者强”,从而抽象出“调和”义的“龢”。金文“龢”的“由乐声之谐和始能引出调义,由乐声之共鸣始能引伸出相鹰义”,则由甲骨文“求禾”的物质层面提升到了精神层面,产生了质的飞跃。     

安徽省农民收入倍增的路径选择

安徽省提出力争到2015年城乡居民收入比2010年翻一番。在分析改革开放后安徽农民纯收入变动的总体特征后,基于收入来源的视角,剖析了安徽农民纯收入的来源构成及其增长源泉,提出了促进安徽农民纯收入倍增的有效路径建议。