Inferences on the lognormal mean for complete samples

In many engineering problems it is necessary to draw statistical inferences on the mean of a lognormal distribution based on a complete sample of observations. Statistical demonstration of mean time to repair (MTTR) is one example. Although optimum confidence intervals and hypothesis tests for the lognormal mean have been developed, they are difficult to use, requiring extensive tables and/or a computer. In this paper, simplified conservative methods for calculating confidence intervals or hypothesis tests for the lognormal mean are presented. In this paper, “conservative” refers to confidence intervals (hypothesis tests) whose infimum coverage probability (supremum probability of rejecting the null hypothesis taken over parameter values under the null hypothesis) equals the nominal level. The term “conservative” has obvious implications to confidence intervals (they are “wider” in some sense than their optimum or exact counterparts). Applying the term “conservative” to hypothesis tests should not be confusing if it is remembered that this implies that their equivalent confidence intervals are conservative. No implication of optimality is intended for these conservative procedures. It is emphasized that these are direct statistical inference methods for the lognormal mean, as opposed to the already well-known methods for the parameters of the underlying normal distribution. The method currently employed in MIL-STD-471A for statistical demonstration of MTTR is analyzed and compared to the new method in terms of asymptotic relative efficiency. The new methods are also compared to the optimum methods derived by Land (1971, 1973).     

跨国并购与我国企业技术进步的相关性分析

近年来，跨国并购逐渐成为我国企业国际化发展以及构建核心竞争能力的重要途径，而跨国并购能否对我国企业的技术进步起到积极的作用则成为理论研究的热点问题。针对此，采用全要素指标体系，分析了1991~2007年全要素增长率与跨国并购增长率之间的关系，认为:跨国并购的变化对技术进步具有一定的影响关系，但是由于技术并购在对外投资中的比重偏低，过分重视了技术的引进，忽视了技术的吸收消化过程等因素的影响，因此这种影响的效果并不显著。     

李正学《毛宗岗小说批评研究》评析

对李正学的《毛宗岗小说批评研究》进行了较为深刻的评析,认为李正学的这部论著将理论性与思辨性贯穿全书始终,在动态中彰显了作者历史意识的通识观,并从现代学术的视野指出毛氏理论的不足,在当代毛评研究中可谓别具一格,独具机抒。     

美国高等教育质量认证机构及其活动特征研究

美国高等教育质量认证活动是非政府、自愿的民间行为,但其认证活动却因科学客观、公正严明而享誉世界。究其原因,笔者认为美国高等教育质量认证机构采取的种种手段、方式方法对质量产生了保证作用,如权威的资格认可、认证机构专家的多元构成、认证标准的个性化和科学规范的操作程序等,学习和借鉴美国高等教育质量认证机构及其活动的特征将有益于我国构建科学、规范的教育质量评估制度。     

Planning for the 1950 Censuses of Population and Agriculture

The change from the z of “Student's” 1908 paper to the t of present day statistical theory and practice is traced and documented. It is shown that the change was brought about by the extension of “Student's” approach, by R.A. Fisher, to a broader class of problems, in response to a direct appeal from “Student” for a solution to one of these problems.     

太平天国战争时期江西信丰的围城与守城——以吴秉衡《信丰守城记事略》为中心的讨论

自咸丰六年(1856)至同治三年(1864),信丰县城及县境经受了与太平军的多次战争,县城几番被围,最长的一次达二百二十余日。由于南赣官府、周边州县以及湘军的支援,另外署理知县吴秉衡的坚守,信丰县城得以保完。署理信丰知县吴秉衡的《信丰守城记事略》记载了太平军、匪寇围城的经过,该文献为认识咸、同时期江西地方史的重要史料,至今尚未得到学界的分析与解读。本文以《信丰守城记事略》等史料为主,讨论了太平军、匪寇的攻城策略,官府的应对措施以及信丰城乡战时的社会秩序等问题。     

Nonparametric regression with cross‐classified responses

In this article, we develop regression models with cross‐classified responses. Conditional independence structures can be explored/exploited through the selective inclusion/exclusion of terms in a certain functional ANOVA decomposition, and the estimation is done nonparametrically via the penalized likelihood method. A cohort of computational and data analytical tools are presented, which include cross‐validation for smoothing parameter selection, Kullback–Leibler projection for model selection, and Bayesian confidence intervals for odds ratios. Random effects are introduced to model possible correlations such as those found in longitudinal and clustered data. Empirical performances of the methods are explored in simulation studies of limited scales, and a real data example is presented using some eyetracking data from linguistic studies. The techniques are implemented in a suite of R functions, whose usage is briefly described in the appendix. The Canadian Journal of Statistics 39: 591–609; 2011. © 2011 Statistical Society of Canada     

寻找快乐的家园——读王安忆长篇小说《上种红菱下种藕》

小说《上种红菱下种藕》表现了上海附近一个小镇上的特殊风景,这里的生活气息浓郁,且温情怡然,这里的人们质朴而善良,这些都是我们向往的最宝贵的东西。在现代化的进程中,经济的、科学技术的现代化一方面带来了富庶和繁荣,另一方面也刮走了精神中的营养。     

我国股票市场指数及指数证券投资组合

运用主成分分析法分析我国上海和深圳两个交易所几个市场指数对市场变化的反应情 况, 结果表明两个股票市场的综合指数和A 股指数可以反应市场的变化, 而其他指数不能反 映各自代表的股票市场变化. 由于这4 个指数都不是一个好的投资组合, 要得到与指数一致的 投资收益需要构造指数投资组合. 本文利用多因子定价模型, 结合统计分析和优化方法, 从每 个股票市场上选取20 余支股票, 经过适当的组合就可以得到与指数一致的收益.