DNA分子近邻互补链碱基的非线性效应

DNA分子近邻互补链碱基的非线性动力学效应研究，综述了Yomosa及Zhang模型，并在改进后的平面转子模型基础上，利用阶乘矩分析方法分析了平面转子模型的非线性效应，结果说明该模型更好的近似性．     

普通螺栓群的偏心受拉分析

对普通螺栓群偏心受拉进行了分析 ,通过工程实际算例对两种简化计算方法与精确计算的结果进行比较 ,并得出相应的结论     

简支吊车梁的活载弯矩包络图

论述了在吊车荷载作用下的简支吊车梁的弯矩包络图的分段、方程求法,最后通过实例说明包络图的绘制。     

An F Approximation to the Distribution of a Linear Combination of Chi-squared Variables.

A three-parameter F approximation to the distribution of a positive linear combination of central chi-squared variables is described. It is about as easy to implement as the Satterthwaite-Welsh and Hall-Buckley-Eagleson approximations. Some reassuring properties of the F approximation are derived, and numerical results are presented. The numerical results indicate that the new approximation is superior to the Satterthwaite approximation and, for some purposes, better than the Hall-Buckley-Eagleson approximation. It is not quite as good as the Gamma-Weibull approximation due to Solomon and Stephens, but is easier to implement because iterative methods are not required.     

旋转体表面摩擦力矩探讨

本文绘出了非跑合情况下由一般曲线所产生的旋转体表面和与其相配合的毂孔表面作相对匀速转动时，相对运动表面摩擦力矩计算的一般公式。     

开缝平板－圆柱传输线解的进一步研究

运用保角变换分析了位于开缝无限大平板上方的圆柱形传输线，给出了这种公输线特性阻抗闭合形式的近似和严格解，这些分析是建立在假设线中只有准ＴＥＭ模传播的基础之上的。     

WORKING TO EXIT POVERTY WHILE CARING FOR CHILDREN'S HEALTH AND DEVELOPMENT IN VIETNAM

Since the implementation of economic reforms in 1986, levels of urbanization, industrialization, and women's labour force participation have increased in Vietnam. This article focuses on the experiences of parents in Vietnam and how labour and social conditions affect their ability to work and exit poverty while caring for their children's health and development. We interviewed a sample of 147 parents in Ho Chi Minh City using in-depth, semi-structured questionnaires. Sixty-three percent of parents had faced loss of income or promotions or had difficulty retaining jobs because they had to care for children. Fifty-eight percent of parents lost income while caring for their sick children because they had to take unpaid leave from work to care for their children or because they had to decrease productivity if they were able to continue working. Fifty percent of parents with school-age children experienced barriers to helping with homework, to attending meetings, or to participating in other aspects of their children's education. The aftermath of the Vietnamese – American War affected parents through loss of extended family members, limiting access to a major traditional source of support. The war had affected other parents by preventing them from completing their education, which left them with job choices that offer little or no work benefits. Although Vietnam has made significant progress in providing early childhood care and education and legislating labour laws, working families’ experiences demonstrate the need to ensure that paid leave and work flexibility policies are available and implemented in all work sectors and to expand affordable, quality child care in order to help low-income working parents in Vietnam meet work demands and exit poverty while meeting their children's needs.     

国际贸易网络与股价崩盘传染:竞争性货币贬值视角

目的/意义当市场面临重大冲击时,虽然不同行业指数在上涨与下挫过程中存在着类似趋势,但依然有着不同的波动特征与溢出特征。设计/方法利用GARCHSK模型刻画我国股票市场各行业不同阶矩的波动特征,并通过溢出指数从静态和动态角度测度2004～2018年期间我国股票市场行业间一阶矩、二阶矩和高阶矩风险溢出的强度和方向。结论/发现研究表明我国股市各行业指数具有明显的高阶矩波动特征,且各阶矩风险联动效应较强,单个行业的风险容易通过行业间的相互作用扩散到整个市场;当危机发生时,相比收益溢出指数较小的变化幅度,波动溢出指数能够及时对市场冲击做出反应,且高阶矩波动溢出指数能更准确地体现出不同行业的特质以及所受冲击的大小。     

Program Evaluation and Causal Inference With High‐Dimensional Data

In this paper, we provide efficient estimators and honest confidence bands for a variety of treatment effects including local average (LATE) and local quantile treatment effects (LQTE) in data‐rich environments. We can handle very many control variables, endogenous receipt of treatment, heterogeneous treatment effects, and function‐valued outcomes. Our framework covers the special case of exogenous receipt of treatment, either conditional on controls or unconditionally as in randomized control trials. In the latter case, our approach produces efficient estimators and honest bands for (functional) average treatment effects (ATE) and quantile treatment effects (QTE). To make informative inference possible, we assume that key reduced‐form predictive relationships are approximately sparse. This assumption allows the use of regularization and selection methods to estimate those relations, and we provide methods for post‐regularization and post‐selection inference that are uniformly valid (honest) across a wide range of models. We show that a key ingredient enabling honest inference is the use of orthogonal or doubly robust moment conditions in estimating certain reduced‐form functional parameters. We illustrate the use of the proposed methods with an application to estimating the effect of 401(k) eligibility and participation on accumulated assets. The results on program evaluation are obtained as a consequence of more general results on honest inference in a general moment‐condition framework, which arises from structural equation models in econometrics. Here, too, the crucial ingredient is the use of orthogonal moment conditions, which can be constructed from the initial moment conditions. We provide results on honest inference for (function‐valued) parameters within this general framework where any high‐quality, machine learning methods (e.g., boosted trees, deep neural networks, random forest, and their aggregated and hybrid versions) can be used to learn the nonparametric/high‐dimensional components of the model. These include a number of supporting auxiliary results that are of major independent interest: namely, we (1) prove uniform validity of a multiplier bootstrap, (2) offer a uniformly valid functional delta method, and (3) provide results for sparsity‐based estimation of regression functions for function‐valued outcomes.