Importance of interpolation when constructing double-bootstrap confidence intervals

We show that, in the context of double-bootstrap confidence intervals, linear interpolation at the second level of the double bootstrap can reduce the simulation error component of coverage error by an order of magnitude. Intervals that are indistinguishable in terms of coverage error with theoretical, infinite simulation, double-bootstrap confidence intervals may be obtained at substantially less computational expense than by using the standard Monte Carlo approximation method. The intervals retain the simplicity of uniform bootstrap sampling and require no special analysis or computational techniques. Interpolation at the first level of the double bootstrap is shown to have a relatively minor effect on the simulation error.     

城镇化、劳动分工与农村市场扩展

市场规模的扩展是影响经济增长的重要因素。在现代社会,从长期来看,市场的扩展取决于劳动分工的演进。如果没有分工的深化,就意味着没有创新和新的产业出现,市场的规模是不会真正扩大的。然而分工的演进又受制于交易效率。在城镇化过程中,人口和产业不断聚集起来,可以极大地提高交易效率,促进分工深化和市场规模的扩展。在当前我国城镇化水平滞后的情况下,扩展市场、扩大内需的根本思路是要加快城镇化进程,进行社会经济结构的调整,促进农村地区的分工深化。     

沿海地区集聚式城市化地域扩张模式及优化

结合我国长三角、珠三角和环渤海湾新型城市化模式的具体案例,分析集聚式城市发展的动力机制和地域扩张模式,认为产业集聚已成为推动沿海区域城市化进程的重要驱动力。论题针对沿海区域集聚式城市化模式存在的问题提出了具体的对策建议。     

零部件循环取货越库物流系统关键因子研究——仿真实验设计与分析方法

汽车和物流产业是国家重点扶持的两大振兴产业． 在众多汽车制造企业产能扩大的背景下,以零部件平均物流时间(cycle time,CT) 为绩效评价指标,深入研究了基于第三方物流的零部件循环取货越库物流模式( 简称 3PL－MRCD) 的优化设计问题． 建立了符合企业实际运作的离散系统随机仿真模型,即零部件循环取货与越库内部运作的集成模型． 与现有供应链仿真模型相比,由于存在较多的仿真因子,提出首先运用序贯分支法( sequential bifurcation, SB) 筛选 3PL－MRCD 系统关键因子,再应用响应面法(response surface methodology,RSM) 找到关键因子最优运作水平的方法步骤( SB－RSM) ,解决了大型仿真系统的优化设计问题． 基于调研的数据进行仿真实验,结果表明 SB－RSM 可准确找出影响CT的关键因子最优取值, 该值使CT达到较为理想的水平． 对大型仿真系统的优化而言,SB － RSM 比传统 RSM 更具实 验效率与效力,SB－RSM 为产能扩大3PL 物流决策的制定提供了可靠的解决方案,具有良好的应用价值．     

住房市场系统模型研究

从宏观层面建立了包含银行、地产商及消费者在内的住房市场系统模型,重点考虑了信贷对住房市场供需双方的金融支持,构建了住房市场系统的定量分析框架,该框架对于银行主导的住房市场具有一般性。通过中国住房市场的实证分析,证实了模型的有效性。     

Nonparametric kernel estimation of expected shortfall under negatively associated sequences

Abstract

In this article, Bahadur type expansions of a nonparametric kernel estimator for ES under NA sequences are given. The strong consistency and the uniformly asymptotic normality of the estimator are yielded from the Bahadur type expansions, while the convergence rates of the above asymptotic properties are also obtained. Moreover, the expectation, the variance and the mean squared error (MSE) of the estimator are given. Besides, the optimal bandwidth selection of this estimator is discussed. We point out that all above results are based on the NA sequences. Finally, we conduct numerical simulations and compare performances of some ES estimators.     

The social and genetic inheritance of educational attainment: Genes,parental education,and educational expansion

Recently, several genome-wide association studies of educational attainment have found education-related genetic variants and enabled the integration of human inheritance into social research. This study incorporates the newest education polygenic score (Lee et al., 2018) into sociological research, and tests three gene-environment interaction hypotheses on status attainment. Using the Health and Retirement Study (N = 7599), I report three findings. First, a standard deviation increase in the education polygenic score is associated with a 58% increase in the likelihood of advancing to the next level of education, while a standard deviation increase in parental education results in a 53% increase. Second, supporting the Saunders hypothesis, the genetic effect becomes 11% smaller when parental education is one standard deviation higher, indicating that highly educated parents are more able to preserve their family's elite status in the next generation. Finally, the genetic effect is slightly greater for the younger cohort (1942–59) than the older cohort (1920–41). The findings strengthen the existing literature on the social influences in helping children achieve their innate talents.     

Navigating challenging contexts: Costs and benefits of codified acquisition experience

Despite its intuitive appeal, acquisition experience has not shown a clear benefit to acquirers, and we argue the applicability of acquisition experience depends on goals and context. Using survey data, we consider the effects of applying codified experience for two common acquisition goals involving knowledge transfer and market expansion. Our findings reveal a ‘double-edged sword’ effect, where on one hand, codification mitigates negative effects of industry rivalry on knowledge transfer. However, on the other hand, codification amplifies negative effects of industry rivalry on market expansion and internal turmoil on knowledge transfer. Beyond demonstrating the importance of goals and context contingencies for determining acquisition experience effect, our results reconcile conflicting research findings to identify when codified experience is beneficial in acquisitions.     

一类非线性Fredholm积分方程的奇摄动

应用匹配渐近展开法研究了一类非线性Fr积分方程。εω(x,ε)+h(x,ε)=integral from n=0 to 1(f(x,s,ω(s,ε)ε)ds,0≤x≤1(其中ε为正的小参数,0<ε≤1)的奇异摄动问题。假设出现边界层以及其他适当的条件,导出了方程解的一致有效的渐近展开式,证明了解的存在性和唯一性,并对余项作出渐近估计,推广了Lange(1988),Olmstead(1989)关于线性Fr积分方程的奇异摄动问题以及Hoppensteadt(1983)关于Volterra积分方程的奇异摄动问题的结果。     

虚阴极振荡在谐振腔中激励微波的理论分析

文中将虚阴极看作一个带电圆盘，用场的模式展开方法讨论了虚阴极振荡在谱振腔中对微波的激励，得到了微波频率、模式与虚阴极振荡的关系。结果表明，在谐振腔较长时容易得到单一频率成分微波，这与试验结果一致。分析还表明，特征频率越接近虚阴极振荡频率的模式，其展开系数就越大。