二维非定常对流扩散方程的高精度紧致半显式差分格

在已有文献的基础上,发展了一种求解二维非定常对流扩散方程的高精度紧致半显式差分格式,其截断误差为O（τ2 ＋h4）,该格式形式上是隐式,但实际上可以显式计算.利用Fourier分析法证明该格式是无条件稳定的.数值实验结果验证了该格式的精确性和可靠性.     

NEWS ACCURACY IN SWITZERLAND AND ITALY

Nearly 80 years of accuracy research in the United States has documented that the press frequently errs, but empirical study about news accuracy elsewhere in the world is absent. This article presents an accuracy audit of Swiss and Italian daily regional newspapers. Replicating US research, the study offers a trans-Atlantic perspective of news accuracy. To compare newspaper accuracy in Switzerland and Italy to longitudinal accuracy research in the United States, the study followed closely the methodology pioneered by Charnley (1936) and adapted by Maier (2005). News sources found factual inaccuracy in 60 percent of Swiss newspaper stories they reviewed, compared to 48 percent of US and 52 percent of Italian newspapers examined. The results show that newspaper inaccuracy—and its corrosive effect on media credibility—transcends national borders and journalism cultures. Nowadays, digitization offers new ways of implementing correction policies. Media organizations need, however, to adapt to these changes and to adapt their structures in particular to new forms of participative and interactive two-way communication.     

三维摄像方法中超出标定范围进行标定的精度分析

为了能够更加深入地了解人体运动和动作技术的细节,为使分析结果更接近实际情况,提高测量数据的准确性,通过对三维摄像中超出标定范围的被标定点进行标定的方法,分析其标定精度,确定误差范围。得到的结论是,针对目前国内研究人员常用的25个控制点的辐射型标定框架,标定范围应控制在距标定框架中心起4.5m的空间范围内,以保证测量数据的准确性。     

内燃机活塞裙面加工精度的BP神经网络控制技术研究

在加工活塞裙面时,传统的控制方法往往是通过直接加工或误差补偿来实现,精度效果往往不能尽如人意,为此,采用BP神经网络控制技术,可以取得令人满意的效果,实验结果表明,这种方法是可行的。     

干部人事档案的准确性及管理初探

分析干部人事档案存在的现象,表现形式及产生的原因,提出提高档案管理,促进档案管理手段科学化,提高人事档案的真实性和准确性的具体措施及其人事档案管理制度亟待改革。     

基于多层约束的叶轮数控进刀精度控制算法

随着工业生产要求的不断增加,对叶轮的精度要求越来越高,这就给数控生产设备的控制精度提出了更高的要求,为了解决这一问题,提出一种基于多层约束的叶轮数控进刀精度控制算法,通过建立数控进刀控制模型,充分考虑进刀中叶轮的复杂情况。运用多层进刀条件约束模型方法,控制进刀精度,最大程度的满足精度要求,后期的计算机仿真实验证明,这种控制算法能够很好的完成叶轮数控进刀的多个约束条件的最优解计算,控制精度有了明显的提高。     

How to achieve accurate peer assessment for high value written assignments in a senior undergraduate course

The psychometric measures of accuracy, reliability and validity of peer assessment are critical qualities for its use as a supplement to instructor grading. In this study, we seek to determine which factors related to peer review are the most influential on these psychometric measures, with a primary focus on the accuracy of peer assessment or how closely peer-given grades match those of an instructor. We examine and rank the correlations of accuracy, reliability and validity with 17 quantitative and qualitative variables for three senior undergraduate courses that used peer assessment on high value written assignments. Based on these analyses, we altered the single most significant variable of one of the courses. We demonstrate that the number of reviews completed per reviewer has the greatest influence on the accuracy of peer assessment out of all the factors analysed. Our calculations suggest that six reviews must be completed per reviewer to achieve peer assessment that is no different from the grading of an instructor. Effective training, previous experience and strong academic abilities in the reviewers may reduce this number.     

语块训练提高大学生英语口语准确性的实证研究

语块使用对提高英语学习者口语能力的积极作用得到了众多学者的认可,但针对这一问题的实证研究尚不多见。本研究采用定量的方法对90名非英语专业学生的语块使用情况与英语口语准确性之间的相关性进行了统计分析,并通过开展语块强化训练实验,用实证的方法探讨了语块训练对提高大学生英语口语准确性的作用,结果发现：1．语块使用与大学生英语口语准确性呈现出显著的正相关;2．语块训练能够有效提高大学生的英语口语准确性;3．语块训练有助于提高学生的英语口语成绩。     

联机手写笔画识别后处理算法的设计与实现

文中提出了两种联机手写笔画识别后处理的优化方案,第一种是基于回溯策略的后处理算法,通过回溯法修正误识的笔画;第二种称为多候选笔画组合算法。本文在基本识别手写笔画的基础上采用这两种后处理算法优化识别程序,实验结果表明,对笔画识别进行后处理大大提高了系统的识别率。