Statistical inference on asymptotic properties of two estimators for the partially linear single-index models

The outer product of gradients (OPG) estimation procedure based on least squares (LS) approach has been presented by Xia et al. [An adaptive estimation of dimension reduction space. J Roy Statist Soc Ser B. 2002;64:363–410] to estimate the single-index parameter in partially linear single-index models (PLSIM). However, its asymptotic property has not been established yet and the efficiency of LS-based method can be significantly affected by outliers and heavy-tailed distributions. In this paper, we firstly derive the asymptotic property of OPG estimator developed by Xia et al. [An adaptive estimation of dimension reduction space. J Roy Statist Soc Ser B. 2002;64:363–410] in theory, and a novel robust estimation procedure combining the ideas of OPG and local rank (LR) inference is further developed for PLSIM along with its theoretical property. Then, we theoretically derive the asymptotic relative efficiency (ARE) of the proposed LR-based procedure with respect to LS-based method, which is shown to possess an expression that is closely related to that of the signed-rank Wilcoxon test in comparison with the t-test. Moreover, we demonstrate that the new proposed estimator has a great efficiency gain across a wide spectrum of non-normal error distributions and almost not lose any efficiency for the normal error. Even in the worst case scenarios, the ARE owns a lower bound equalling to 0.864 for estimating the single-index parameter and a lower bound being 0.8896 for estimating the nonparametric function respectively, versus the LS-based estimators. Finally, some Monte Carlo simulations and a real data analysis are conducted to illustrate the finite sample performance of the estimators.     

Spatial Differentiation and Driving Forces of Migrants’ Socio-Economic Integration in Urban China: Evidence from CMDS

Migrants’ socio-economic integration is a major theme in migration research, which can provide economic and cultural benefits. And it will contribute to social stability. The investigation from the spatial perspective should also be considered. This paper aims to examine the spatial differentiation of the socio-economic integration of migrants and identify its driving forces to provide crucial evidence and policy recommendations to urban policymakers and further improve migrants’ socio-economic integration. Based on the latest China Migrants Dynamic Survey, this paper uses global Moran’s I index, hot spot analysis and GWR model to explore spatial differentiation and driving forces of the socio-economic integration of 155,789 migrants in 291 cities at prefecture level and above in China. The results show that: (1) The socio-economic integration of migrants consists of five dimensions, which are economic integration, cultural integration, social security, social relation and psychological integration. Among them, psychological integration is the highest (73.16) and economic integration is the lowest (13.38). (2) The socio-economic integration of migrants is mainly influenced by their own characteristics instead of the destination characteristics. Four factors (age, education, length of stay and population growth rate) positively affect migrants’ socio-economic integration, while three factors (inter-provincial mobility, proportion of tertiary industry in GDP, and ratio of teacher to student in middle school) negatively impact the socio-economic integration of migrants. (3) The socio-economic integration of migrants shows the distribution pattern of agglomeration. And the integration also presents a significant spatial heterogeneity. The driving forces of the socio-economic integration exhibit various zonal spatial differentiation patterns, including “E–W”, “SE–NW”, “NE–SW”, and “S–N”. Finally, some useful recommendations are given for improving migrants’ socio-economic integration.

     

长期护理需求评估体系建设研究——基于地方试点与德国实践

长期护理需求评估是长期护理保险筹资与给付的联结点,直接决定了保险给付,并对长期护理保险筹资有重要影响.当前我国试点地方在长期护理需求评估制度的设计上分歧较大,虽积累了差异化的经验与案例,但地区分割不利于社会公平与社会流动.应立足于长期护理保险的社会保险属性,结合社会实际与试点效果,适当借鉴德国经验,统筹设计长期护理需求评估体系,通过"法律+行政法规+部门规章"的规范形式,精准定位评估对象,明确独立的评估主体、科学设计评估指标与评估工具、严格规范评估程序等确保评估结果的科学、客观与公正,并根据评估结果进行分级分类给付,实现长期护理保险资源流向精准.     

语域理论视角下的新疆政务微博

文章从系统功能语言学语域理论的角度出发,分析了新疆政务微博语场方面的技术性和系统性、语旨方面的权力关系和平等关系下的情态动词、语式方面的口语体和书面语体以及新疆汉语方言。同时,根据其语域表现出的严肃与亲和的二重性,兼顾新疆多民族语言的并存的现状,提出了应通过新疆政务微博的语场进一步了解民意、利用权力平等关系发布消息和新疆政务微博应适当使用新疆汉语方言的建议。     

Relation between the skew-rank of an oriented graph and the independence number of its underlying graph

An oriented graph \(G^\sigma \) is a digraph without loops or multiple arcs whose underlying graph is G. Let \(S\left( G^\sigma \right) \) be the skew-adjacency matrix of \(G^\sigma \) and \(\alpha (G)\) be the independence number of G. The rank of \(S(G^\sigma )\) is called the skew-rank of \(G^\sigma \), denoted by \(sr(G^\sigma )\). Wong et al. (Eur J Comb 54:76–86, 2016) studied the relationship between the skew-rank of an oriented graph and the rank of its underlying graph. In this paper, the correlation involving the skew-rank, the independence number, and some other parameters are considered. First we show that \(sr(G^\sigma )+2\alpha (G)\geqslant 2|V_G|-2d(G)\), where \(|V_G|\) is the order of G and d(G) is the dimension of cycle space of G. We also obtain sharp lower bounds for \(sr(G^\sigma )+\alpha (G),\, sr(G^\sigma )-\alpha (G)\), \(sr(G^\sigma )/\alpha (G)\) and characterize all corresponding extremal graphs.     

西藏县级农牧民专业合作经济组织的现状、问题及制约因素分析——以拉孜县的实地调查为例

拉孜县作为西藏自治区十个重点商品粮基础县之一,农牧民专业合作经济组织近年来发展迅猛,对当地的农牧业经济水平的提升和农牧民增收起到了非常重要的作用。但调查也揭示,拉孜县农牧民专业合作经济组织还存在以经营原材料或初级产品为主,缺乏品牌与特色,产品附加值不高覆盖率低、整体规模小、经济实力弱,带头人的效应发挥不够等问题,需要政府进一步培育、指导和扶持。     

对海洋霸权与大陆均势关系的再探讨

虽然以往研究海洋霸权与大陆均势关系的成果颇丰,但还是存在一些不足。为此,本文对海洋霸权与大陆均势关系的结构类型、运行机制及其影响等进行了深化与细化。在海洋霸权国国力大于或小于或等于大陆均势中的有关国家的不同情况下,大陆均势可以分为不需要海洋霸权仅凭大陆国家就能形成的大陆均势和需要海洋霸权且支持其中一方才能形成的大陆均势。不同的国力对比和均势构成情况,对海洋霸权与大陆国家的政治安全与经济发展所产生的影响是不同的。经过分析和比较,本文得出结论:海陆分界难分优劣,关系互补战略呼应,这就是美英极力推行海洋霸权与大陆均势战略的现实诠释。     

水基泡沫流变特性研究进展

水基泡沫在石油钻井、驱油及矿物浮选等方面应用广泛，但因其自身结构的复杂性及不稳定性，准确描述其流变性需要考虑液膜排液、气体扩散、泡沫质量、泡沫结构、可压缩性、壁面滑移、测量系统相对于气泡的尺寸、环境温度及压力等多方面因素，以致于目前尚无有关泡沫流变性的公认理论。实验研究过程中控制壁面滑移的较普遍做法是增加流道壁面（转子表面或管壁）的粗糙度，基于适当假设所提出的一些理论修正方法具有较好的适应性。体积平衡法假设泡沫管流摩擦系数为常量，在一定程度上解决了泡沫可压缩性给管流压降计算所带来的困难。目前普遍认为泡沫流变性可用幂律模式或赫谢尔–巴尔克莱模式很好地描述，是否存在“屈服应力”则因测试条件差异而存在争议。