Use of the Extreme Groups Approach: A Critical Reexamination and New Recommendations.

Analysis of continuous variables sometimes proceeds by selecting individuals on the basis of extreme scores of a sample distribution and submitting only those extreme scores to further analysis. This sampling method is known as the extreme groups approach (EGA). EGA is often used to achieve greater statistical power in subsequent hypothesis tests. However, there are several largely unrecognized costs associated with EGA that must be considered. The authors illustrate the effects EGA can have on power, standardized effect size, reliability, model specification, and the interpretability of results. Finally, the authors discuss alternative procedures, as well as possible legitimate uses of EGA. The authors urge researchers, editors, reviewers, and consumers to carefully assess the extent to which EGA is an appropriate tool in their own research and in that of others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

极大代数意义下幂矩阵的周期性特征

在分析一类离散事件动态系统的运行周期性及稳定性时,必须求解极大代数意义下矩阵的特征值。这一直被认为是十分困难的工作。直至目前为止,尚无一种能确定任一方阵全部特征值及特征向量的简易方法。本文对极大代数意义下任一方阵的幂矩阵的周期性特征进行了深入分析。本文的结果为寻求计算特征值及特征向量的新算法提供了十分有效的途径。     

Extremes of random fields over arbitrary domains with application to concrete rupture stresses

To find the exact probability distribution of the global maximum or minimum of a random field within a bounded domain is a pending problem even for Gaussian fields. Except for very special examples of fields, recourse must be taken to approximate reasoning or asymptotic considerations to be judged with respect to accuracy by simulations. In this paper, the problem is addressed through a functional equation that leads to the definition of a class of distribution functions that depend solely on process or field characteristics and domain quantities that can be calculated explicitly. This distribution function class is studied for Gaussian processes in earlier works by the author and it has been obtained explicitly for Gaussian fields on rectangular domains in the plane. Simulation studies show that rather good predictions are obtained for sufficiently smooth wide band Gaussian processes and fields. In this paper, the distribution function is obtained in general for Gaussian fields over arbitrary bounded domains with piecewise continuous and differentiable boundaries, and as in earlier works the distribution function is tested against empirical distribution functions obtained by simulation of sample functions of a smooth approximately Gaussian field, herein called a broken line Hino field. For completeness this particular field type is defined in appendix a and appendix b. The paper concludes with a statistical application on data for plain concrete tensile strength.     

质子和中子的单粒子效应等效性实验研究

通过实验方法确定了高能质子和中子引起的单粒子效应等效关系，实验中采用金箔散射法降低了质子束流强度，并利用热释光剂量计（TLD）进行质子注量的监测，采用新研制的存储器长线实时监测系统，进行了64K位至4M位的SRAM器件单粒子效应实验，确定了两种粒子引起单粒子效应等效关系。     

Locked discrete event systems: How to model and how to unlock

To model qualitative aspects of discrete event systems, i.e., the order of the events is of sole importance, we use a triple consisting of the set of all possible events (the alphabet), the set of all behavior (possible strings of events), and the set of all tasks (completed behavior). We use this view to model synchronous as well as asynchronous connection of systems. Moreover, it is easy to define notions like deadlock and livelock in this view. We give a method to construct a second system that, in connection with the original system, gets rid of its deadlock and/or livelock. A state-space representation is introduced. In this representation computations can be done effectively.     

离散事件动态系统的代数模型及其控制器的分析计算

本文在离散事件动态系统的Ｐｅｔｒｉ网图形描述的基础上建立了相应的代数模型，该模型可以用来计算无竞争无回路Ｐｅｔｒｉ网的“最大状态”；该“最大状态”的计算在本文给出的动态反馈控制器中得到了应用。     

扩展有限递归进程模型

主要讨论离散事件动态系统的建模问题。由ＫＩｎａｎ和ＰＶａｒａｉｙａ提出的有限递归进程（ＦＲＰ）是描述并发离散事件动态系统的有力工具，但在其ＦＲＰ中，没有定义对数据变量的操作和条件转移算子。本文扩展ＦＲＰ包括这两方面内容。最后举例说明扩展ＦＲＰ的描述能力。     

CAD^2B—一个计算机辅助数据库设计系统

本文介绍了一个用Ｔｕｒｂｏ Ｃ语言在ＡＳＴ－２８６机器上实现的计算机辅助数据库设计系统ＣＡＤ＾２Ｂ。该系统提供了人机交互的环境，供设计者进行概念模型设计，并自动完成从概念模型逻辑模型的映射，创建满足规范化要求的关系表。该系统采用的概念模型是引入了事件和时间的扩展了的实体关系模型。该模型既能充分反映应用环境的静态和动态语义，又是向关系模式转化的基础。     

安徽省旱涝急转规律的认识与研究

旱涝急转是指某一地区或某一流域发生较长时间干旱时，突遇集中强降雨，引发山洪暴发、河水陡涨．客水入侵、内水难以及时外排的一种自然现象。旱涝急转极易造成人员伤亡、水库垮坝等重大经济损失。在防汛抗旱中，安徽省要充分认识旱涝急转的危害性，加强应急管理，具体包括思想上保持高度的警觉，加快防汛抗旱工程体系和预测预警体系建设，有效应对旱涝急转。     

全球气候变暖对水资源的影响

全球气候变暖加剧了干旱、洪涝、台风等自然灾害的发生，是目前各国政府和社会公众普遍关注的热点问题。根据有关资料对气候变暖研究进展情况作相关介绍，可供参考。