Fast robust feature screening for ultrahigh-dimensional varying coefficient models

In this paper, we propose a new partial correlation, the so-called composite quantile partial correlation, to measure the relationship of two variables given other variables. We further use this correlation to screen variables in ultrahigh-dimensional varying coefficient models. Our proposed method is fast and robust against outliers and can be efficiently employed in both single index variable and multiple index variable varying coefficient models. Numerical results indicate the preference of our proposed method.     

An overlook on statistical inference issues for stochastic damping hamiltonian systems under the fluctuation-dissipation condition

ABSTRACT

In this paper, we are interested in nonparametric inference issues for stochastic damping hamiltonian systems under the fluctuation-dissipation condition. This condition relates the magnitude of the dissipative term and the magnitude of the random term. The precise balance between the drift term which removes energy in average and the stochastic term provided by the fluctuation-dissipation relation insures that the canonical measure is preserved by the dynamics. In this framework, it is possible to give an explicit construction of a Lyapunov function and thus to prove exponential ergodicity. Then, we consider various estimation procedures and provide also a numerical section, where simulations are conducted.     

How social media matter: Repression and the diffusion of the Occupy Wall Street movement

This study explores the role played by social media in reshaping the repression-mobilization relationship. Drawing on the case of the Occupy Wall Street movement, we examine the impact of Facebook and Twitter on the spatial diffusion of protests during a period of heightened state repression. Results from event history analyses suggest that the effects of repression on protest diffusion are contingent on the presence of social media accounts supporting the movement. We find that state repression at earlier protest sites encouraged activists to create Facebook and Twitter accounts in their own cities, which then served as important vehicles for the initiation of new Occupy protests. Moreover, results suggest that repression incidents can directly facilitate future protests in cities that already have Occupy Facebook accounts. This study highlights the potential of social media to both mediate and moderate the influence of repression on the diffusion of contemporary movements.     

Parameter estimation for multivariate diffusion processes with the time inhomogeneously positive semidefinite diffusion matrix

Statistical inference for the diffusion coefficients of multivariate diffusion processes has been well established in recent years; however, it is not the case for the drift coefficients. Furthermore, most existing estimation methods for the drift coefficients are proposed under the assumption that the diffusion matrix is positive definite and time homogeneous. In this article, we put forward two estimation approaches for estimating the drift coefficients of the multivariate diffusion models with the time inhomogeneously positive semidefinite diffusion matrix. They are maximum likelihood estimation methods based on both the martingale representation theorem and conditional characteristic functions and the generalized method of moments based on conditional characteristic functions, respectively. Consistency and asymptotic normality of the generalized method of moments estimation are also proved in this article. Simulation results demonstrate that these methods work well.     

甘肃省人口压力评估指标及定量评估研究

在对传统人口压力评价指标体系评述的基础上，将无形资源纳入人口压力评价指标体系，根据2006年甘肃省统计资料。对全省81个县级行政区划单位的人口压力进行赋值与量化。结果表明甘肃省人口压力量化值呈正态分布．有形资源与无形资源都丰富的地区人口压力较小，人口压力与社会经济发展水平密切相关。实现甘肃社会经济的可持续发展．必须注重人口压力区域差异的合理调控。     

民族素质是构成现代发展概念的重要内涵--民族素质研究之五

本文从与发展内涵相关的人类发展的诸项指数、国家实力概念的探讨情况,论述了民族素质在现代发展概念中的重要地位.     

An Exploration of the Need to Build an Evaluation Index System for Economic and Social Development in the Southwest’s Ethnic Region

An evaluation index system for eco￣nomic and social development is guiding the trends and actions of economic development in different countries or regions. However,the evaluation index system should b...     

基于灰色系统建模技术的人体疾病早期预测预警研究

传统健康体检主要通过对单次体检指标进行横向比较和静态分析,忽略个体差异,纯粹从指标高低来判断体检者健康状况与身体状态,难以及时发现体检者可能存在的疾病隐患。由于个体体检指标具有样本量小、信息不确定、数据类型异构、影响因素构成复杂等特征,传统以大样本为基础的数学模型均难以适应此类小数据系统的建模要求。为此,通过建立适用于人体主要指标趋势预测的灰色系统模型（简称HIGM（1,1）模型）,实现对人体主要健康指标的动态建模与趋势分析,从而可以掌握体检者未来一段时间身体指标的变化趋势及可能存在的疾病隐患。研究成果对提升体检效果、强化体检意义,促进灰色理论与现实问题的有效对接等方面,均具有积极意义。     

中国沪深股市的开盘效应与收盘效应

股票市场的日历效应历来受到学者和投资者的广泛关注,研究发现股市存在节日效应、月份效应与周内效应,但是针对日内效应的研究不多见.利用沪深股指2004年~2016年的高频数据,实证检验中国沪深股市是否存在日内效应,结果表明:中国沪深股市整体上存在开盘效应与收盘效应,但在牛市、熊市期间的表现形式存在差异,股指收益在牛市期间表现出正向开盘效应,在熊市期间表现出负向开盘效应,股指波动在熊市期间的开盘效应更为明显.基于滚动窗口法的进一步研究发现:股指收益开盘效应和收盘效应的变化领先于股指走势的变化,股指收益和波动的开盘效应或收盘效应存在一定程度的替代现象.研究有助于投资者合理地制定投资策略,对监管部门维护市场秩序具有一定的参考价值.     

公司治理对农村商业银行全要素生产率的影响研究

构建GML指数测度25家农村商业银行2008-2014年的全要素生产率增长,在剖析公司治理对全要素生产率影响机理的基础上,利用面板模型对相关因素进行实证分析。研究发现：样本农村商业银行的全要素生产率总体明显提高,个体间的增速差异逐渐缩小;董事会规模、董事会会议频率和自有资本比率的提高对生产率的增长具有积极作用,但股权制衡度和市场份额的提高不利于生产率的增长;股权集中度、独立董事比例和监事会规模的影响不显著。