大地上的疤痕

村子西边,原来没有任何建筑.十几年前的一个晚春,也许是晚春过后的初夏,台子地靠近村子的这一侧,一座高高的砖窑拔地而起,横空出世.一时间,祖祖辈辈以耕为生、以农为本的生活常态,遭遇到了一波前所未有的冲击,不啻一场地震降临.     

Experiences of Families Inquiring About Donating or Adopting Embryos: Results of an Online Survey

Four hundred thirty-four individuals who had previously inquired with the National Embryo Donation Center (NEDC) or Nightlight Christian Adoptions about donating or adopting embryos responded to an online survey regarding which issues had been raised with them during their inquiry and how well they perceived NEDC and/or Nightlight had answered their questions regarding those issues. In general, respondents perceived that the operational issues surrounding donating or adopting embryos received more attention than the longer-term issues involving family dynamics and relationships. Overall, the inquirers were pleased with the responses to their questions (average >8 on a satisfaction scale of 1–10).     

A tutorial on rank-based coefficient estimation for censored data in small- and large-scale problems

The analysis of survival endpoints subject to right-censoring is an important research area in statistics, particularly among econometricians and biostatisticians. The two most popular semiparametric models are the proportional hazards model and the accelerated failure time (AFT) model. Rank-based estimation in the AFT model is computationally challenging due to optimization of a non-smooth loss function. Previous work has shown that rank-based estimators may be written as solutions to linear programming (LP) problems. However, the size of the LP problem is O(n ²+p) subject to n ² linear constraints, where n denotes sample size and p denotes the dimension of parameters. As n and/or p increases, the feasibility of such solution in practice becomes questionable. Among data mining and statistical learning enthusiasts, there is interest in extending ordinary regression coefficient estimators for low-dimensions into high-dimensional data mining tools through regularization. Applying this recipe to rank-based coefficient estimators leads to formidable optimization problems which may be avoided through smooth approximations to non-smooth functions. We review smooth approximations and quasi-Newton methods for rank-based estimation in AFT models. The computational cost of our method is substantially smaller than the corresponding LP problem and can be applied to small- or large-scale problems similarly. The algorithm described here allows one to couple rank-based estimation for censored data with virtually any regularization and is exemplified through four case studies.     

神经网络的滚动轴承故障诊断

文章通过旋转机械故障实验平台,采集旋转机械故障实验台轴承的3种工作状态分别是轴承正常、轴承内圈裂缝、轴承外圈裂缝的振动加速度信号.对信号进行零均值化处理后,选择频率成分幅值较大的频率进行信号重组,提取其时域量纲特征值,利用神经网络进行故障类型的识别；通过实验,取得了很好的诊断结果.     

柴桥镇种植业的调查及发展构想

文章分析了柴桥镇种植业所取得的成绩和存在的问题，并提出了发展种植业的措施和对策。     

从法理上对税收负担最小化手段的再界定——税收筹划概念的内涵和外延

目前关于税收负担最小化手段的理解多种多样 ,对税收筹划及相关概念的使用很不规范 ,容易误导纳税人的行为和国家的税收征管。本文从法理上将税收负担最小化手段划分为偷逃骗税和税收筹划 ,又将税收筹划划分为避税、节税和税负转嫁     

FPK法在集总参数系统随机温度研究中的应用

应用FPK法研究了集总参数系统在对流和辐射环境下温度随机变化的规律。设激励是均值为0的白噪声且系统参数为常量，在与环境对流换热时，系统随机温度的均值不变，方差与系统时间常数的平方根成反比；在与环境辐射换热时，系统随机温度一般不呈正态分布，其中均值，均方值还与系统确定性温度有关，由此可知，当存在随机激励时，用有热惯性的测温系统精确测定动态温度是不可能的。     

微波管CAD技术进展

传统的经验设计方法很难综合性地进一步提高微波管的功率、带宽、增益、效率及非线性特性等性能,高精度的微波管CAD模拟软件是改进设计,提高性能的主要手段。该文综述了微波管CAD技术的国内外研究进展,介绍了微波管CAD软件的主要分类及代表性软件,特别是我国自主研发的二维宽带大功率行波管CAD集成环境软件系统及三维微波管模拟器套装。展望了微波管CAD技术的发展前景,对我国自主开发微波管CAD软件提出了一些建议。     

人性、文化传统与道德理论的合理性——美国后分析道德理论争论述评

究竟有没有一种作为道德基础的不变的人的本性？道德理论有没有一种建立在人性基础上的惟一的客观性和合理性？我们应当如何看待和说明我们的道德理论和辩护方式的多样性和合理性？这些问题是后现代道德理论争论的焦点，是有着重大的现实理论和实践意义的课题。本文以美国后分析道德哲学的发展、争论为线索，对以上问题作了初步的历史的探讨