Penalized proportion estimation for non parametric mixture of regressions

Abstract

In this article, we propose a penalized local log-likelihood method to locally select the number of components in non parametric finite mixture of regression models via proportion shrinkage method. Mean functions and variance functions are estimated simultaneously. We show that the number of components can be estimated consistently, and further establish asymptotic normality of functional estimates. We use a modified EM algorithm to estimate the unknown functions. Simulations are conducted to demonstrate the performance of the proposed method. We illustrate our method via an empirical analysis of the housing price index data of United States.     

我国房地产开发投资规模测算及影响因素研究

随着我国供给侧改革的逐步落实,房地产行业产能过剩、结构性有效供给不足的情况得到了一定程度的改善,但产能过剩与房地产开发投资规模不合理情况一直存在.采用1997-2014年数据,对我国房地产开发投资规模进行合理测算,并运用回归模型进行实证研究,结果发现:城市化率、居民消费价格指数增长率以及第三产业对GDP的贡献率对我国房地产开发投资规模的影响显著.     

不同震级作用下的设备 结构动力相互作用体系地震反应分析

为研究是否考虑设备 结构动力相互作用在不同地震阶段的差别,对建筑结构中常见的设备 结构相互作用体系进行了小震、中震和大震阶段的地震时程反应分析。分析了不同震级作用下考虑相互作用后给结构与设备的地震反应带来的变化。结果表明：考虑设备 结构动力相互作用与不考虑相互作用相比,结构的地震反应有较明显的区别,设备的地震反应有很大的区别,处于完全失真的状态。大震阶段由于设备和结构均进入了弹塑性阶段,刚度等主要参数发生了变化,导致动力相互作用的影响降低。虽然设备质量占结构总地震质量的比例很小,但仍会对结构位移与内力造成较大的影响。     

Testing Serial Correlation in Partially Linear Additive Errors-in-variables Models

This article considers testing serial correlation in partially linear additive errors-in-variables model. Based on the empirical likelihood based approach, a test statistic was proposed, and it was shown to follow asymptotically a chi-square distribution under the null hypothesis of no serial correlation. Finally, some simulation studies are conducted to illustrate the performance of the proposed method.     

Robust Smoothed Rank Estimation Methods for Accelerated Failure Time Model Allowing Clusters

Smoothed Gehan rank estimation methods are widely used in accelerated failure time (AFT) models with/without clusters. However, most methods are sensitive to outliers in the covariates. In order to solve this problem, we propose robust approaches based on the smoothed Gehan rank estimation methods for the AFT model, allowing for clusters by employing two different weight functions. Simulation studies show that the proposed methods outperform existing smoothed rank estimation methods regarding their biases and standard deviations when there are outliers in the covariates. The proposed methods are also applied to a real dataset from the “Major cardiovascular interventions” study.     

基于地质遗迹景观的川西藏区生态旅游开发研究

地质遗迹是自然文化遗产的重要组成部分,越来越成为旅游开发的“核心”资源。文章聚焦拥有数量众多、类型丰富的地质遗迹景观川西藏区,通过梳理川西藏区地质演化历史,阐释了该区域地质遗迹形成的背景,同时对该地区地质遗迹景观进行分类和评价,并在此基础上提出川西藏区依托地质遗迹景观开发生态旅游的对策建议。     

论违约责任和侵权责任的竞合处理

违约责任与侵权责任是两种性质不同的民事责任,侵权责任保护的是固有利益,在合同签定、履行过程中可能有侵权性违约行为、违约性侵权行为发生,从而会产生违约责任和侵权责任竞合的情形。合理分析和处理违约责任和侵权责任竞合的不同情形,对最大限度地维护当事人的合法权益会起到积极作用。     

Parental Leave Policies and Second Births: A Comparison of Czechia and Slovakia

Population Research and Policy Review - The paper investigates the transition to second births in Czechia and Slovakia in the context of the development of parental leave policies since the...     

Life Satisfaction of Rural Migrant Workers in Urban China: The Roles of Community Service Participation and Identity Integration

Abstract

China is home to approximately 245 million rural-to-urban migrant workers. The influx of migrants into urban areas has posed various challenges for local social service systems. Recently, increasing number of community services have been developed to meet the growing service demands from the migrant population. However, whether increase in community service use results in improved wellbeing among migrant workers remains critically unexplored. As such, this study examines the role of community service use in migrant workers’ life satisfaction and the potential mediating effect of identity integration in Shenzhen, China. Bootstrapped models were adopted to examine relationship among variables. Drawing from a sample of 1,087 rural-to-urban migrant workers, we found that community service use is positively correlated with both identity integration and migrant workers’ life satisfaction. Moreover, identity integration served as a partial mediator between community service use and life satisfaction. The mediating effect of identity integration was found to increase with age. This study highlights that diverse services should be implemented to address divergent needs of migrants in different age groups. Community service can also serve as a vehicle to foster integration among migrant workers in host communities, especially for older age groups. Future studies may further investigate the relationships between community social capital, community social support, quality of community-based organization and frequency of service use so as to optimize the life satisfaction of migrant workers.     

The effect of paid maternity leave on low-income families' welfare use in the US

Despite the critical role that paid maternity leave can assume in the economic lives of low-income families, research to date has paid insufficient attention to whether paid maternity leave reduces welfare use for low-income families. Using the Current Population Survey (CPS) March Supplement 2007–2014 with the difference-in-difference (DiD) technique, this study finds a significant policy effect of paid maternity leave on reducing the probability of using Temporary Assistance for Needy Families (TANF), TANF benefit amounts and TANF participation length. This study confirms that paid maternity leave is likely to prevent low-income families from using welfare during job interruptions stemming from the birth of a child. Given that TANF is often associated with negative political and social connotations, paid maternity leave can be used as an important social policy to improve economic security as well as offer empowerment in overall social standing for low-income mothers. The discussion focuses on the implications of the findings in a broader context of American welfare states.