Estimation of Mode Using Two-phase Sampling

In this article, we consider the problem of estimation of mode using two-phase sampling. Ratio- and difference-type estimators in two-phase sampling are proposed. The asymptotic properties of the proposed estimators are studied analytically as well as empirically for different situations for the given cost of surveys. The use of two-phase sampling has been found to be cost saving design while estimating mode by making a proper use of auxiliary information.     

中国金融对经济增长贡献的效率研究——金融发展的阶段划分及评价

通过聚类分析将改革开放以来的中国金融-经济系统分为传统金融时期、金融转型初期、金融转型中期三个阶段,然后选取资本存量、劳动力、金融机构人民币资金来源、M2、贷款余额作为投入变量,GDP作为产出变量,采用非径向超效率分析模型测度中国金融效率。研究表明:中国的金融-经济系统存在结构变化,金融的绝对效率较低,但相对效率水平较高,中国已经顺利完成了金融体系的转型。     

Another look at the robustness of colton's model for comparing two medical treatments

The robustness of an extended version of Colton's decision theoretic model is considered. The extended version includes the losses due to the patients who are not entered in the experiment, but require treatment while the experiment is in progress. Among the topics considered are the effects of risk of using a sample size considerably less than the optimum, use of an incorrect patient horizon, application of a modified loss function, and use of a two point prior distribution. It is shown that the investigated model is robust with respect to all these changes with the exception of the use of the modified prior density.     

积分变换求梁的变形

本文从求解梁挠度的二阶差分方程出发，通过Z变换，最后推导出计算挠度和转角的简单公式，使计算过程简化。对于变截面梁和复杂受载下，此法尤为简便。同时，这也是处理离散参数的数学方法—Z变换在力学中应用的初步尝试。     

在公正与效率之间:证人出庭作证制度的困境和出路

证人出庭作证问题,涉及证明标准与法律假设、法律规则与法律标准、诉讼效率与诉讼成本、自利偏见与社会效应等诸多方面。证人不出庭作证的规范依据仍然存在、证人出庭作证的权利和义务不对等、配套措施不完善等原因,导致证人不愿意出庭。美国辩诉交易制度在很大程度上减少了开庭刑事案件的数量,其关于书面陈述的规定也减少了证人出庭作证的需求,在一定程度上实现了被告人人权保护和公共利益的平衡,值得借鉴。完善证人出庭作证制度,应以案件"客观需要"为标准,以追求事实真相为出发点,以人权保护和人性回归为落脚点,遵循限制性处罚原则和禁止利益冲突原则,提高相关规定的可操作性。因此,不宜盲目追求证人高出庭作证率。     

简析宪法中的效率原则

宪法中的效率原则包含4个范畴。其中,最大化原则无法被比例原则所涵盖。若不考虑最大化原则,在审查国家财政任务的合宪性时,效率原则可以被视为比例原则的重要组成部分。作为一项宪法原则,效率原则不仅约束行政机关,而且约束立法机关。对于行政机关而言,由审计机关审查其活动是否符合效率原则。而对于代议机关而言,审查其行为是否符合效率原则的任务可以交给违宪审查机关,审计机关在必要时须提供专业咨询和建议。     

Testing variance components in balanced linear growth curve models

It is well known that the testing of zero variance components is a non-standard problem since the null hypothesis is on the boundary of the parameter space. The usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold because of this null hypothesis. To circumvent this difficulty in balanced linear growth curve models, we introduce an appropriate test statistic and suggest a permutation procedure to approximate its finite-sample distribution. The proposed test alleviates the necessity of any distributional assumptions for the random effects and errors and can easily be applied for testing multiple variance components. Our simulation studies show that the proposed test has Type I error rate close to the nominal level. The power of the proposed test is also compared with the likelihood ratio test in the simulations. An application on data from an orthodontic study is presented and discussed.     

天然岩芯化学驱采收率机理的一些认识

用牛顿流体驱替一定的均质多孔介质系统结果显示，驱油效率由驱替液的毛管数决定。用化学液驱替天然岩芯时，除毛管数以外，还有很多其他因素影响驱油效率。天然岩芯，即使在宏观上是均匀的，在微观上也不均匀；驱替时所得到的效率一般被称为驱油效率，实质上是微观波及效率和驱油效率的乘积。牛顿流体没有弹性，驱替时，体系的润湿性不发生变化，不出现渗吸作用，不形成乳液，孔隙的几何形状不发生变化。但是，用化学液驱替天然岩芯时，由于化学液为粘弹性，体系有润湿性的改变，会出现乳化现象，渗吸作用也会出现。上述因素都会影响驱油效率，尤其是当多种因素同时作用时。分析了极限采收率和经济采收率的区别。很多文章都论述极限采收率，但经济采收率对油田的作用更大。化学驱应考虑上述因素，这对设计、开发、筛选化学剂以及确定驱油体系会是有益的，将深化我们对化学驱机理的认识，促进这方面更深入的研究。     

Sequential estimation problems for negative exponential populations

The literature on sequential estimation problems for negative exponential populations has been reviewed here, We attempt to bring in all the published and unpublished materials known to us in a fairly coherent fashion. Both the concepts and theoretical findings are discussed.     

Testing for exponentiality against monotone failure rate average alternatives

We propose a test for exponentiality against the class of non-exponential distributions having monotone failure rate averages. The test statistic, which is a U-statistic and hence asymptotically normally distributed, is much simpler than its competitors yet compares favorably with them in efficiency and power comparisons.