Does class-size reduction close the achievement gap? Evidence from TIMSS 2011

Policies about reducing class size have been implemented in the US and Europe in the past decades. Only a few studies have discussed the effects of class size at different levels of student achievement, and their findings have been mixed. We employ quantile regression analysis, coupled with instrumental variables, to examine the causal effects of class size on 4th-grade mathematics achievement at various quantiles. We use data from 14 European countries from the 2011 sample of the Trends in International Mathematics and Science Study (TIMSS). Overall, there are no systematic patterns of class-size effects across quantiles. Class-size effects are generally non-significant and uniform at different achievement levels, which suggests that in most European countries class-size reduction does not have an impact on student achievement and does not close the achievement gap. However, combined estimates across countries indicate that high achievers may benefit more from class-size reduction.     

不确定性条件下企业信息系统的云化决策方法

企业在决策本地化信息系统转换为云模式的软件即服务时面临着技术市场发展、云化收益、决策者风险偏好等诸多不确定性。针对该决策,引入前景理论考虑了维持现状偏好、追求管理时尚等心理行为,依据交易成本理论和技术组织环境理论提取了决策指标,以未来不同的软件即服务市场成熟度作为前景状态,计算各备选信息系统云化迁移的综合前景值,形成不确定性条件下企业信息系统的云化决策方法。同时,应用该方法实例分析了一家企业,并与基于期望值的灰色随机多准则决策方法进行了比较,说明了该方法的可行性和合理性。     

用CSocket类实现点对点通信

本文简要介绍了在VC＋＋中网络编程的几种方式及通信协议，重点讲解了在VC＋＋中使用CSocket类按照二进制数据格式点对实现点通信的一种简单方法。     

基于软件体系结构的管理信息系统模型

在软件体系结构理论的指导下，提出了一个面向企业管理信息系统、具有层次体系结构风格的在一定范围内通用的管理信息系统软件体系结构模型GMISA。     

一种基于Log4J的日志输出组件的设计

在软件开发和系统的运行过程中,日志管理是一个非常重要的部分。通过对在Log4J的基础上设计出适用于特定系统的日志输出组件进行的研究,从而减少了系统中大量冗余代码,提高了开发效率及开发的一致性。     

Challenges of measuring software impact through citations: An examination of the lme4 R package

The rise of software as a research object is mirrored by increasing interests in quantitative studies of scientific software. However, inconsistent citation practices have led most existing studies of this type to base their analysis of software impact on software name mentions, as identified in full-text publications. Despite its limitations, citation data exists in much greater quantities and covers a broader array of scientific fields than full-text data, and thus can support investigations with much wider scope. This paper aims to analyze the extent to which citation data can be used to reconstruct the impact of software. Specifically, we identify the variety of citable objects related to the lme4 R package and examine how the package’s impact is dispersed across these objects. Our results shed light on a little-discussed challenge of using citation data to measure software impact: even within the category of formal citation, the same software object might be cited in different forms. We consider the implications of this challenge and propose a method to reconstruct the impact of lme4 through its citations nonetheless.     

《百家讲坛》收视文化研究

《百家讲坛》作为央视科教频道的一档知识讲座类栏目,随着其热播,引发诸多争论,最终演变成一个值得深思的文化事件。通过对该栏目观众收视行为的多层次分析,反观其文本潜在的多义性,反映其用以编码的一套意识形态话语策略内部存在的矛盾,矛盾背后凸显的是央视这一处于特殊地位的传媒机构与书斋型学术自治场对接而形成的文化资本,经电视这一大众媒介转换成大众文化资本过程中存在的悖论。     

《中国图书馆分类法》（第5版）新增类目与加“0”类目重号问题分析

《中国图书馆分类法》（以下简称《中图法》）（第5版）新增类目与加＂0＂类目之间存在着重号问题,这需要《中图法》编委会、相关分类专家和文献分类领域同仁认真思考。例如,《中图法》（第5版）中的一处新增类目＂K870.5金石学＂与加＂0＂复分类目＂K870.5中国文物考古调查发掘报告＂存在类目内容不同但分类号码相同的重号问题,可以采用其他非数字符号取代作为转换不同分类标准时的标记符号＂0＂的方法加以解决。     

浅谈《中图法》第五版“中国地区表”修订

《中国图书馆分类法》第五版通过修改类名、扩充加细类目、增加注释等修订方法,使得"中国地区表"在科学性、实用性和兼容性方面有了明显进步。但仍存在一些疏漏,尚有待于再版修订时加以改进和完善。