Full information maximum likelihood estimation in factor analysis with a large number of missing values

We consider the problem of full information maximum likelihood (FIML) estimation in factor analysis when a majority of the data values are missing. The expectation–maximization (EM) algorithm is often used to find the FIML estimates, in which the missing values on manifest variables are included in complete data. However, the ordinary EM algorithm has an extremely high computational cost. In this paper, we propose a new algorithm that is based on the EM algorithm but that efficiently computes the FIML estimates. A significant improvement in the computational speed is realized by not treating the missing values on manifest variables as a part of complete data. When there are many missing data values, it is not clear if the FIML procedure can achieve good estimation accuracy. In order to investigate this, we conduct Monte Carlo simulations under a wide variety of sample sizes.     

硕士生公共英语教学重在语言技能的培养

目前硕士生公共英语教学存在着不足之处，一是学习目标不明，二是知识和技能不分。因此有必要对这一时期语言技能培养的重要性和可行性进行论证。     

国际法体系下南极生物勘探的法律规制研究

南极生物遗传资源具有极大的经济和应用价值,各国积极开展南极生物勘探活动和激烈的资源争夺。发达国家和发展中国家在南极遗传资源的法律属性、利用与保护等问题上持有不同的政治立场,并展开了激烈的国际争论。国际上并无专门的关于南极生物勘探及其遗传资源的法律文件,现有的国际法律制度对此均有所涉及,但在适用上具有一定的局限性。所以南极生物勘探及其遗传资源相关问题的解决不是一个国际文件就可解决的复杂问题,因此须扩展适用区域制度和公海自由原则,发挥联合国的宏观作用,扩展全球公共利益的范围,广泛应用人类共同遗产原则,并在国际法和南极条约体系的协调和融合下寻求解决的方法。     

On approximations to the inverse student’s-t distribution function

The inverse of the Student's t-distribution is often needed in computer simulation and applied statistics, e.g, in generating random variates from t-distributions and in computing tables needed for statistical procedures which do not assume known variances. The t-distribution algorithm of Dudewicz and Dalal (1972) can be used to approximate the inverset t distribution function. The author notes an algorithm for evaluation of this inverse d.f. which can be implemented in a fast, accurate and short computer program. The error analysis is also reported. An application is considered for the problem of testing the hypothesis that a sequence of random variates follows Student's-t distribution.     

A GENEALOGY OF CORRESPONDENCE ANALYSIS

Over the past half a century correspondence analysis has grown from a little known statistical technique designed to graphically depict the association structure of categorical variables that form a contingency table to a very popular tool used in a wide variety of disciplines. Despite this growth, correspondence analysis remains relatively unknown in some parts of the world, including the Australasian statistical community. This paper provides a non‐technical, bibliographic exploration of correspondence analysis. We take a step back to view the development of this statistical technique and provide a brief account of its genealogy with a selection of over 270 key publications that have contributed to its growth. We also look at its maturity over the decades.     

科技期刊转企改制的对策研究

从2011年以来我国非时政类报刊转企改制的改革背景入手,立足科技期刊,提出科技期刊坚持"为人民出版,替科研服务"的职责与出版精品期刊的质量目标、强化经营意识与服务意识、打造学习型期刊社等对策。以科学发展观为指导,把握方向,分析路径,提供思路,加强非时政类期刊转企改制的应对探讨,从而推进我国科研事业的发展有着极其重要的意义。     

遗传资源信息权:遗传资源知识产权战略的基本权利

为了有效保护遗传资源,有必要创设一种新型权利。根据遗传资源的内在属性,将此种新型权利称为"遗传资源信息权"。遗传资源信息权是一种不具有明显创造性的新型权利,具有无形性、地域性、强复制性等特征。权利创设必然涉及利益分配,有关遗传资源的权利设计应当实现土著社区与现代生物技术公司、发展中国家与发达国家的公平利益分享。综合考虑中国国情及法律传统,结合遗传资源信息权的权利内容,建议遗传资源信息权的设计采用国家主导下的集体所有模式。     

试谈歌词结尾反复的艺术程式

反复是歌词创作中高频率运用的一种修辞手段，歌词结尾反复的艺术程式有：无阶式和有阶式及其升、降格式，分析了反复对歌词结尾程式的艺术处理的修辞作用。     

二苯基乙炔及双二茂铁基乙炔与Fe_3(CO)_(12)的反应性研究

本文以十二羰基三铁Fe3(CO)12作为催化剂前体,研究了Fe3(CO)12分别与两种炔烃的反应性能。结果表明,当炔烃为二苯基乙炔时,可以同时得到四苯基环戊二烯酮化合物(1)和具有铁碳五元环状结构的双核铁羰基配合物(2);而与双二茂铁基乙炔反应时,仅获得了一个产物四二茂铁取代环戊二烯酮羰基铁配合物(3)。这类反应产物种类繁多,通过设计该类反应,可为合成不同取代基的环戊二烯酮类化合物提供一条新的途径。     

完善安徽省中小企业发展扶持体系的对策

中小企业的发展对增加就业、保持经济增长、调整产业结构起着积极的作用。文章分析了中小企业扶持体系的内涵、安徽省中小企业发展扶持体系建设取得的成果及存在的问题，探讨了完善安徽省中小企业发展扶持体系需要采取的有效措施，以期为安徽省扶持中小企业发展提供参考。