A Note on Confidence Intervals for a Linear Function of Poisson Rates

We consider three interval estimators for linear functions of Poisson rates: a Wald interval, a t interval with Satterthwaite's degrees of freedom, and a Bayes interval using noninformative priors. The differences in these intervals are illustrated using data from the Crash Records Bureau of the Texas Department of Public Safety. We then investigate the relative performance of these intervals via a simulation study. This study demonstrates that the Wald interval performs poorly when expected counts are less than 5, while the interval based on the noninformative prior performs best. It also shows that the Bayes interval and the interval based on the t distribution perform comparably well for more moderate expected counts.     

Efficient Confidence Interval Methodologies for the Non Centrality Parameter of a Non Central t Distribution

This article considers the problem of constructing a confidence interval for the non centrality parameter of a non central t distribution. This has applications to the signal to noise ratio in regression problems and to the coefficient of variation for normally distributed data. A new procedure is developed that provides shorter confidence intervals than the standard procedure, and a program is available for its implementation. This new procedure will be useful for practitioners, and its development also provides some interesting theoretical results.     

Confidence intervals for the largest mean from k correlated normal populations

Let X= (X₁,…, X_k)’ be a k-variate (k ≥ 2) normal random vector with unknown population mean vector μ = (μ₁ ,…, μ_k)’ and covariance matrix Σ of order k and let μ_[1] ≤ … ≤ μ_[k] be the ordered values of the μ ’ s. No prior knowledge of the pairing of the μ_[i] with the X_j. (or μ_[i] with the σ_j ²) is assumed for any i and j (1 ≤ i, j ≤ k). Based on a random sample of N independent vector observations on X, this paper considers both upper and lower (one-sided) and two-sided 100γ% (0 < γ < 1) confidence intervals for μ_[k] and μ_[1], the largest and the smallest mean, respectively, when Σ is known and when Σ is equal to σ²R with common unknown variance σ² > 0 and correlation matrix R known, respectively. An optimum two-sided confidence interval via finding the shortest length from this class is also considered. Necessary tables and computer program to actually apply these procedures are provided.     

《胜券在握》中的人物刻画及语言特色

美国作家及漫画家詹姆斯.瑟伯在其短篇小说《胜券在握》中,通过合理地变换叙事角度和使用恰当贴切的词语,成功地塑造了马丁先生和巴罗斯夫人两个现代都市白领阶层的人物形象,使读者在感情上深深地受到感染,并在思想上产生强烈的共鸣。     

哈尔滨市土地储备风险评价研究

以哈尔滨市区土地储备为研究对象,按照研究区土地利用布局均匀采取样点,引用数学模型定量计算各样点的风险值。根据风险值的大小将土地储备风险划分为Ⅰ级、Ⅱ级、Ⅲ级三个等级,并分析造成地块风险差异的原因,提出通过增强土地市场的透明度、确定合理的土地储备量、采用多渠道的经营方式和完善土地储备投资的风险分析等措施,降低哈尔滨市土地储备风险。     

基于GARCH模型的VaR方法对中国股市的分析

中国股票市场的收益率具有厚尾性 ,可以利用GARCH模型中的条件方差来度量其VaR。我们运用了基于不同分布假定下的GARCH模型的VaR方法对深圳股票市场与上海股票市场的风险进行了分析。分析的结果表明深圳股票市场比上海股票市场有更大的风险 ;用t分布和GED分布假定下的GARCH模型能够更好地反映出收益率的风险特性     

“五月生子不举”习俗考释

《史记》中有＂五月生子不举＂的记载,古今注者往往困惑于此,或者避而不谈。经过广泛调查和仔细分析,我们发现＂五月生子不举＂的习俗的产生有其复杂的原因,不但有现实的环境的原因,比如气候暑热、虫疫流行等,也有民间积累下来的观念因素,比如认为五月子命硬、不祥和忤逆等。     

学习型组织中的“学习主体”类型与案例研究

通过对国际知名的、长盛不衰的学习型组织(摩托罗拉、惠普、通用电气等) 深入的案例研 究, 指出员工是学习型组织中真正的学习主体, 并提出了以“自愿式(vo lun tary) —要求式( re2 qu ired) ”、“个人式( individual) —团队式( team ) ”两个维度所形成的四种“学习主体”类型(即I2 V 型, T 2V 型, I2R 型, T 2R 型) 及其运作案例. 最后提出了影响组织选择这四种不同类型“学习 主体”时的相关因素.     

The power(lessness) of Czechoslovak Jews during the Second World War

The article evaluates the perceptions of Jewish power among the Czechoslovak exiles in Britain during the Second World War. The analysis documents the apparent persistence of prejudices against the Jewish minority among the Czechoslovak non-Jewish authorities that eventually formed the government-in-exile (1940–5), under the presidency of Edvard Bene? (1884–1948). The Czechoslovak exiles believed that the Jewish minority, in particular the Jewish nationalists (Zionists), had vehement supporters within Jewish circles in Western countries. Furthermore, they believed that the Jewish press played a significant role in the formation of public opinion in Britain and especially in the United States. In the early 1940s, the government-in-exile embarked on a policy of national homogenisation of post-war Czechoslovakia and was anxious to give concessions to the political representatives of the ethnic minority groups in exile, in particular the Germans, Hungarians and Jews. Yet the concerns about Jewish influence in liberal democracies granted several political concessions to the Jewish minority, in particular the appointment of a Zionist representative, Arno?t Frischer (1887–1954), to the exile parliament. This notwithstanding, by analysing the internal situation among the Czechoslovak Jewish groups in London, the article documents the internal weakness and disputes among the Jewish groups which gradually revealed the utter powerlessness of the Jewish exiles during their negotiations with the Czechoslovak authorities. The Jewish groups (the assimilationists, Orthodox and secular nationalists) were divided by mutual as well as internal disputes which were not concealed from outside observers and were utilised by the exile government. What emerges from the analysis is an impression of quarrelling groups that could not agree on any of the fundamental issues and whose only power was the ability to court the support of Western Jewish groups, which were perceived by the non-Jewish exiles as influential actors in US and British society.