A NEW CLASS OF MODELS FOR THE DISCRIMINANT PROBLEM

Discriminant analysis is relevant to business decision making in a variety of contexts, such as when one decides to make or buy a specified component, fund a venture project, or hire a particular person. Potential applications in artificial intelligence, particularly in the area of pattern recognition, have further underscored the importance of the field. A recent innovation in discriminant analysis is provided by special linear programming (LP) models, which offer attractive alternatives to classical statistical approaches. The scope of application in which discriminant analysis can be advantageously employed is broadened by the flexibility to tailor parameters in the LP approaches to reflect diverse goals and by the power to explore the sensitivity of these parameters. In spite of the promise of the LP formulations, however, limitations to their effectiveness have been uncovered in certain settings. A recent advance involving a normalization construct removes some of the limitations but entails solving the LP model twice (to allow for different signs of a normalization constant) and does not yield equivalent solutions for different rotations of the problem data. This paper introduces a new model and a new class of normalizations that remedy both remaining limitations, making it possible to take advantage of the modeling capabilities of the LP formulations without the attendant shortcomings encountered by earlier investigations. Our development shows by empirical testing and illustrative analysis that the quality of solutions from LP discriminant approaches is more favorable (relative to the classical model) than previously supposed.     

A Variable Selection Criterion in the Linear Programming Approaches to Discriminant Analysis*

There are numerous variable selection rules in classical discriminant analysis. These rules enable a researcher to distinguish significant variables from nonsignificant ones and thus provide a parsimonious classification model based solely on significant variables. Prominent among such rules are the forward and backward stepwise variable selection criteria employed in statistical software packages such as Statistical Package for the Social Sciences and BMDP Statistical Software. No such criterion currently exists for linear programming (LP) approaches to discriminant analysis. In this paper, a criterion is developed to distinguish significant from nonsignificant variables for use in LP models. This criterion is based on the “jackknife” methodology. Examples are presented to illustrate implementation of the proposed criterion.     

美国大学的中国留学生助教课堂语用失误案例剖析

美国大学的中国留学生助教在课堂教学中的跨文化交际反映着中国教育的一个侧面。研究以一个助教“nevermind”的语用失误个案出发,从语用学和跨文化交际深入探析其背后反映出来的语言和文化根源。指出语言本身是基于语境的,更根植于其所依存的文化。语言的理解和使用要符合话语行为的基本原则,更要跳出字面理解和母语文化影响的桎梏,看到更大的语言结构和语境。此研究目的是呼吁外语教育从关注纯语言向语言和语用并重的应用型转变,同时希望为在海外从事跨文化教学的群体在本土化教学意识方面提供有益的借鉴。     

电子技能教学中引入CBE模式的思考

CBE是以职业综合能力为基础的教育体系,它以达到某一种职业的从业能力为教学目标。CBE教学模式在高职院校“电子技能实训”中应用,可以构建电子技能实训新的教学体系,拓宽实训途径,培养学生自主学习能力．从而提高职业综合能力。     

大学化学系列课程教学改革的研究与实践

论述了非化学化工类专业大学生,实施高教层次的化学教育的必要性、教学目标和教学改革的思路。总结了课题组的研究成果。     

试论倾听技巧在少数民族预科汉语教学中的作甩

人的一切实践活动都离不开听,听力是人类直接获得信息最为重要的手段之一。少数民族预科汉语教学的目标是培养“听、说、读、写”的能力,而“倾听技巧”在实现这一目标的过程中所起的作用是显而易见的。因此,汉语教师在努力探讨自身在提高课堂教学效果的同时,也有必要探讨倾听技巧在教学中的作用,只有教师和学生互相认真倾听对方心声,课堂气氛才能活跃。文章拟对倾听技巧在少数民族汉语教学中的作用及师生双方在课堂上如何运用倾听技巧进行探究。     

新疆民考民大学生英语自主学习情况调查分析

文章通过摸底实验、问卷调查和访谈形式,对少数民族大学生的英语自主学习情况和思想动态做了一次全面调查。发现民考民大学生的英语自主学习情况不尽人意。民考民大学生在进行英语自主学习时,对老师能给予合适的帮助的期望值较高。认为民考民大学生的英语自主学习效果与教师的有效教学和指导紧密相关,自主学习应是教师与学生共同操作和完成的过程,是一个合作体,离开教师的有效教学和指导的自主学习只会使教与学步入困境,导致无效学习。     

浅谈电子商务专业英语的课程建设及模块化教学

文章针对电子商务的应用在国际贸易中不断加强以及对电子商务专业人才的需求,指出了电子商务专业英语课程设置的必要性,并提出引入模块化教学改革的方法以强化电子商务专业英语的课程建设。     

模具设计课程教学与企业实践中的几点不同之处

依据高职院校模具专业人才培养能力定位，结合模具企业工作岗位能力要求，结合教学与模具企业工作实际，提出了模具设计课程教学中需要增设的内容，希望能对该专业教师及教辅人员有一定启发和帮助，并能达到良好的教学效果与预期的教学目标。     

历史上最早记载《三字经》的文献——《三字经》成书于南宋中期新说

南宋慈溪人桂氏《家训》中的一条记载,填补了《三字经》早期文献的空白。桂氏《家训》约成书于嘉定年间,《三字经》应成书于南宋绍熙至嘉定年间。桂氏《家训》的发现,使现知《三字经》的文献记载由明中叶一下子推进到了南宋中期,整整提前了近四百年,不但从根本上动摇了王、区两说的立论基础,而且在客观上证明了宁波是现知《三字经》最早的流传地区,慈溪桂氏家族最早将《三字经》列为蒙学教材用以教育子弟。