A restricted subset selection procedure for Weibull populations

Consider k(k ≥ 2) two-parameter Weibull populations. We want to select a subset of the populations not exceeding m in size such that the subset contains at least ? of the t best populations. We have proposed a procedure which uses either the maximum likelihood estimators or ‘simplified’ linear estimators of the parameters. The estimators are based on type II censored data. The ranking of the populations is done by comparing their reliabilities at a certain fixed time. In selected cases the constants for the procedure are tabulated using Monte Carlo methods.     

A New Formulation For The Multinomial Selection Problem

The two approaches to a multinomial ranking and selection problem (for selecting the t best cells out of k are combined to form a new apprach. In this new approach there is a preference zone (PZ) and an indifference zone (IZ), and the concept of a correct selection (CS) is defined differentlv in eac of these zones. Lower bounds for the probability of correct selection p(CS) are then guaranteed in each of these zones using a single experiment. The procedure on the ordered frequencies in the cells. The principle tool used to derive expressins for the p(CS). for the expected sample size EN, for the expected subsct size ES and for other probabilities. is the Dirichlet integral (Type 2) which was recent tabulated. These Dirichlet integrals are used to prove that the multiplicative slippage configuratin is leas favorable in the PZ and, for t = l, that the IZ. Numerical calculations are carried out for an illustrative example but extensive tables are not yet avalable

     

国有企业战略收缩的理论依据——一个经济学模型的思考

将国有资产和非国有资产置于平等地位,即市场主体地位的平等必然要求资产作为国民经济功能性工具的地位平等,然后通过建立国家利益无差异曲线模型,引入“边际资本成份替代率”和“有效区间”等概念,论述了该模型对我国企业改革的意义,得出如下结论：国有资产在行业与市场中的过度介入,是目前我国国有企业低效率的制度性原因,国有企业战略收缩是增加国家的国际竞争力的唯一途径。     

女性"政治冷漠"的现象分析及其消除对策

在提出女性“政治冷漠”的表现与危害的基础上,对其形成的原因进行了分析,寻求了消除女性“政治冷漠”的对策。女性政治冷漠形成的主要原因有：封建文化的负面影响,政治制度设计上的不足,女性公民政治参与素质欠缺,社会生产力发展不充分。消除女性政治冷漠的有效途径有：构建平等而先进的性别文化,提高女性公民参与意识和参与素质,创建参与型政治文化,完善政策机制;充分发展社会生产力。这对于发展社会主义民主政治和建设社会主义政治文明,具有重要酊理论意义和实践意义。     

效用函数意义下投资组合有效选择问题的研究

我们知道,每个投资者在进行投资过程中,都有自己对收益与风险的偏好程度,即投资活动要遵循一个关于收益与风险的效用函数。按照古典经济学的分析,这个效用函数称为无差异曲线 (IDC),它是用均值 -方差来表现风险 -回报率相互替换的大小和形式的。每个投资者都拥有一条无差异曲线来表示他对于预期回报率和标准差的偏好。那么投资者如何确定他的一条无差异曲线,使他的最佳资产组合位于这条无差异曲线上 ?本文运用自己独创的一种几何方法解决了这个难题。本文首先把Markowitz模型的有效前沿用投资组合的权重向量表示出来,然后将无差异曲线也用抽资组合的权重向量表示出来,再由资产组合的有效选择原则就求出这个无差异曲线了。     

On lower confidence bounds for pcs in truncated location parameter models

We are concerned with deriving lower confidence bounds for the probability of a correct selection in truncated location-parameter models. Two cases are considered according to whether the scale parameter is known or unknown. For each case, a lower confidence bound for the difference between the best and the second best is obtained. These lower confidence bounds are used to construct lower confidence bounds for the probability of a correct selection. The results are then applied to the problem of seleting the best exponential populationhaving the largest truncated location-parameter. Useful tables are provided for implementing the proposed methods.     

高校大学生生命教育调查与分析——以江西省高校为个案研究

当前大学生生命意识的淡薄反映了家庭、高校和社会生命教育的缺乏。大学生生命教育缺失的原因是多方面的,有家庭、学校和社会多重因素。要扎实有效地推进生命教育,需要学校教育充分与社会、家庭教育相结合,与生活经验结合,再回归于日常生活的实践。     

试论当前公民政治冷漠的深层原因及消解对策

当前公民政治冷漠的深层次原因主要是：经济水平不发达，政治参与机制不健全，政治文化比较落后，政治参与成本高昂等。而大力发展经济，实现政治参与制度化，培育公民文化和发展网络政治参与是消除公民政治冷漠的重要攀措。     

Determination of sample size for selecting the smallest of k poisson population means

A procedure for selecting a Poisson population with smallest mean is considered using an indifference zone approach. The objective is to determine the smallest sample size n required from k ≥ 2 populations in order to attain the desired probability of correct selection. Since the means procedure is not consistent with respect to the difference or ratio alone, two distance measures are used simultaneously to overcome the difficulty in obtaining the smallest probability of correct selection that is greater than some specified limit. The constants required to determine n are computed and tabulated. The asymptotic results are derived using a normal approximation. A comparison with the exact results indicates that the proposed approximation works well. Only in the extreme cases small increases in n are observed. An example of industrial accident data is used to illustrate this procedure.     

On a conjecture concerning the least favorable configuration of certain two-stage selection procedures

Given k normal populations with unknown means and a common known variance a two-stage procedure p₁ with screening in the first stage to find the population with the largest mean using the indifference-zone approach is under concern. It was proposed and studied previously by Cohen (1959), Alam (1970) and Tamhane and Bechhofer (1977, 1979). But up to now a conjecture concerning the least favorable parameter configuration of p₁remained unproved for k ≥ 3. In this paper we give a non-standard proof of the conjecture in case of k = 3 for p₁. which (under minor changes) works also for a simplified version of p₁,. Besides, a counterexample is provided to show that another (more intuitive) method of proof fails to work.