Non parametric mixture of strictly monotone regression models

In this article, we propose the non parametric mixture of strictly monotone regression models. For implementation, a two-step procedure is derived. We further establish the asymptotic normality of the resultant estimator and demonstrate its good performance through numerical examples.     

灰色多级排队供应链系统的稳定性测度方法

文章以供应链网络为研究基础,建立了一种灰色多级排队供应链系统,并采用多级排队网络方法研究受到达率和服务时间间隔两个扰动量影响时该系统的稳定性测度方法.验证结果显示:对于受到扰动量影响的灰色多级排队供应链系统,均能快速达到稳定状态,且扰动量能改善供应链系统的整体性能,即使出现异常值,该值变化的波动性也较小;在稳定状态后因具有相对固定量的库存水平,系统不再受其他因素的制约,显示了较强的鲁棒性特征.     

政府推动型城市化促进了县域经济发展吗

文章基于“撤县设区”改革的政策实验,使用一种纯数据推动的合成控制评估思路,分析了政府推动型城市化模式对县域经济发展的影响.研究结果表明:①政府推动型城市化,在大多数地区发挥了中心城市经济发展的辐射和援助作用,但是短期内未能带来人口的实质性城市化;②在影响渠道上,这一城市化进程增强了县域财政的收支能力,同时强化了辖区政府在公共服务事务上的支出,进而发挥着对县域经济发展的促进作用.但是本文的研究也表明,在政府推动型高速城市化背景下,需要警惕假性城市化及延缓县域经济发展的双重隐患,过快或干预过多的城市化模式也可能会损害经济的健康发展.     

分位数单位根检验的拓展及其应用研究

在不同的分位下对时间序列数据是否含有结构性变化进行甄别,对于准确识别数据的动态变化及其分布特征具有重要的意义.本文首次在Koenker和Xiao(2004)研究的基础上提出傅立叶分位数单位根检验模型,并以此捕捉时间序列中存在的结构突变点,进而刻画数据在不同分位下的动态变化特征.本文通过构建傅立叶QKS统计量并采用蒙特卡罗方法对傅立叶分位数模型的临界值、样本容量和检验“势”进行模拟,发现含有傅立叶级数的分位数单位根检验对刻画“尖峰厚尾”特征数据的非线性偏离动态调节特征具有更高的检验“势”.最后,本文利用拓展后的模型对我国通货膨胀的持久性和失业的回滞效应进行再检验,结果发现我国通货膨胀具有平稳的特征,而失业率却包含单位根过程.本研究为分位数单位根检验的拓展及其应用提供了一定的启示.     

彼此相倚:解决物业冲突的有效途径——以C市业主与物业冲突为例

社会心理学家巴克的"非对称性相倚"和"彼此相倚"理论是解释业主和物业冲突与合作的有效理论.由于信息、权力、收费服务和对利益理解等的不对称,使"非对称性相倚"成为业主与物业冲突的主要根源;而通过成立业主委员会,加快推进物业管理的社会化、市场化和专业化,明确双方定位、利益共享等"彼此相倚",则是解决业主与物业冲突的有效途径.     

A three-stage variable selection method for supersaturated designs

A supersaturated design (SSD) is a design whose run size is not enough for estimating all main effects. Such a design is commonly used in screening experiments to screen active effects based on the effect sparsity principle. Traditional approaches, such as the ordinary stepwise regression and the best subset variable selection, may not be appropriate in this situation. In this article, a new variable selection method is proposed based on the idea of staged dimensionality reduction. Simulations and several real data studies indicate that the newly proposed method is more effective than the existing data analysis methods.     

受限制的市场化:近代浙南五谷会研究

浙南石仓的五谷会是典型的近代乡村会社组织,它由多名会首出资发起组成,以宗教崇拜集会为主要形式,并以此为背景展开借贷活动。五谷会具有清代传统会社的基本特点,但在近代石仓萧条的经济形势下,也出现了新的变化。五谷会会内借贷的实际利率上升趋势明显,会首与会众两相分离并显示出"营业性"的某些特点,这些面向均反映了一种"市场化"的趋势。但与此同时,这种市场化又受到了多重因素的制约:会内仍有着特殊的利率优惠,会首并不存在很大的逐利空间,会众仍普遍以当地的宗族网络作为入会借贷的信用凭借。在这个意义上,五谷会仍未丧失其互助性民间组织的基本特征。     

Likelihood-based and Bayesian methods for Tweedie compound Poisson linear mixed models

The Tweedie compound Poisson distribution is a subclass of the exponential dispersion family with a power variance function, in which the value of the power index lies in the interval (1,2). It is well known that the Tweedie compound Poisson density function is not analytically tractable, and numerical procedures that allow the density to be accurately and fast evaluated did not appear until fairly recently. Unsurprisingly, there has been little statistical literature devoted to full maximum likelihood inference for Tweedie compound Poisson mixed models. To date, the focus has been on estimation methods in the quasi-likelihood framework. Further, Tweedie compound Poisson mixed models involve an unknown variance function, which has a significant impact on hypothesis tests and predictive uncertainty measures. The estimation of the unknown variance function is thus of independent interest in many applications. However, quasi-likelihood-based methods are not well suited to this task. This paper presents several likelihood-based inferential methods for the Tweedie compound Poisson mixed model that enable estimation of the variance function from the data. These algorithms include the likelihood approximation method, in which both the integral over the random effects and the compound Poisson density function are evaluated numerically; and the latent variable approach, in which maximum likelihood estimation is carried out via the Monte Carlo EM algorithm, without the need for approximating the density function. In addition, we derive the corresponding Markov Chain Monte Carlo algorithm for a Bayesian formulation of the mixed model. We demonstrate the use of the various methods through a numerical example, and conduct an array of simulation studies to evaluate the statistical properties of the proposed estimators.     

地下空间开发对城市环境地质的影响及保护措施浅谈

城市地下空间作为一种资源在城市发展中扮演着重要的角色。地下空间具有恒温、恒湿、抗震、防爆、绝热、封闭和可开拓性好的特点,所以开发地下空间比建造地面工程有着独特的优势,目前开发和利用地下空间已成为我国大中城市解决人口、资源、环境危机和医治“城市综合症”的重要措施,也是实施城市可持续发展的重要途径。     

“90后”大学生入学教育新模式探索

高校应针对"90后"大学生的特点及独特的个性,探索新的教育途径和方法。