嵌入式移动数据库中数据广播技术的研究

数据广播是解决嵌入式移动数据库系统用户规模庞大及网络通信非对称性问题的一种有效方法。服务器将大多数用户频繁访问的热点数据以一定的方式组织起来，主动周期性地广播出去，这样充分利用了有限的网络带宽，极大地提高了系统的可伸缩性。在数据广播技术的研究中，需要解决广播的数据调度问题。本通过比较数据广播的平坦调度与非平坦调度，说明多盘调度的优越性，并且通过理论分析推导出数据广播平均访问时间的理论最优值。     

CDMA技术在数据通信系统中的应用

人类对更高质量无线通信的需求推动了CDMA技术的出现．CDMA是按照码型结构的差别来分割信号的．在CDMA系统中，用户数的增加相当于背景噪声的增加．在保持高质量通话的同时，CDMA可以容纳更多的用户，CDMA手机的用户每次通话时，系统编码有4．4万亿种可能的排列，具有天然的保密性，其消息在空中信道上被截获的概率几乎为零．CDMA技术的标准化，推进了这项技术在世界范围内的应用．     

大数据视域下高校学生精准资助的模式探究

高校学生精准资助是我国精准扶贫政策在高校领域的有效延伸,它能够提升高校扶贫工作的针对性、目的性和精准化。当前,在“互联网+”背景下,借助大数据技术推进贫困生精准资助工作成为高校学生精准资助的崭新模式。通过对大数据的科学内涵、基本价值、大数据助推高校精准资助工作的必要性以及当前大数据视域下高校学生精准资助工作存在的问题进行客观准确分析,提出了大数据视域下高校学生精准资助模式建构的有效路径。     

基于GPRS无线网络的集中抄表系统设计

针对配电网结构复杂、位置分散、数据采集困难等问题,提出了一种将嵌入式软硬件技术和基于GPRS（General Packet Rdtio Service）无线通信技术相结合的远程自动抄表系统,可自动完成用户电度表网络的远程数据采集、记录、实时监测、统计分析、打印和供电控制等管理工作.该设计系统构建简单,不受地理位置限制,性价比高,工作稳定可靠.     

(Re)braiding to tell: using trenzas as a metaphorical–analytical tool in qualitative research

Metaphors can be used in qualitative research to illuminate the meanings of participant experiences and examine phenomena from insightful and creative perspectives. The purpose of this paper is to illustrate how I utilized trenzas (braids) as a metaphorical and analytical tool for understanding the experiences and perspectives of Latina teachers around being a well-educated person. Accordingly, this paper is organized into three strands. First, I discuss trenzas as a metaphorical concept in raced–gendered epistemology, highlighting the work of Chicana/Latina feminist scholars in law and education. Second, I describe how metaphorical thinking informed the methodological design. Third, I explain how I used trenzas to make sense of data and build theory. The discussion weaves the three strands together to emphasize the functional and generative nature of trenzas as a metaphorical–analytical tool for gaining critical and nuanced understandings of how personal, professional, and community identities shape participant’ experiences and perspectives.     

基于PDA设计的电力数据采集器

本文提出一个运行在WindowsCE操作系统的PDA上实现电力数据采集器的基本解决方案，并描述了各部分的设计和实现方法．在收集大量资料的基础上，作者根据自己的产品开发经验和工程的实际要求，提出了许多关键的实现方法．选用现有PDA产品设计成手持式抄表机是一个很好的方案．     

Modeling Partial Knowledge on Multiple‐Choice Items Using Elimination Testing

Single‐best answers to multiple‐choice items are commonly dichotomized into correct and incorrect responses, and modeled using either a dichotomous item response theory (IRT) model or a polytomous one if differences among all response options are to be retained. The current study presents an alternative IRT‐based modeling approach to multiple‐choice items administered with the procedure of elimination testing, which asks test‐takers to eliminate all the response options they consider to be incorrect. The partial credit model is derived for the obtained responses. By extracting more information pertaining to test‐takers’ partial knowledge on the items, the proposed approach has the advantage of providing more accurate estimation of the latent ability. In addition, it may shed some light on the possible answering processes of test‐takers on the items. As an illustration, the proposed approach is applied to a classroom examination of an undergraduate course in engineering science.     

挖掘频繁子树精简基

为了解决频繁树模式挖掘中频繁子树的数目通常太大的问题,提出了频繁子树精简基的概念,精简基由相对于一系列支持度阈值的最大频繁子树组成,它是频繁子树的一个子集,可用来估计任一频繁子树的支持度,并能将误差控制在确定范围内.提出了一个在带标号的有根的有序树的数据库中挖掘这种子树精简基的算法,该算法采用最右扩展方法系统地生成所有的频繁有序有根子树.采用的剪枝技术能尽早地剪掉一些不可能生成最大频繁子树的分枝,还采用了启发式的技术来安排计算的次序以尽可能避免代价高的计算.实验结果表明该精简基的大小不到全集的10%,算法的性能也比挖掘全集的算法要高.     

预防网络安全漏洞的程序设计

漏洞是在硬件、软件、协议的具体实现或系统安全策略上存在的缺陷,可以使攻击者能够在未授权的情况下访问或破坏系统。常见的漏洞有windows系统的漏洞、IE浏览器的漏洞等等,其实平时编程特别是网站程序中也存在着许多安全漏洞。现在的网站特别是稍大一些的网站,一般都采用ASP、     

Examining Normality in Incomplete Data Sets: A Note on a Multiple Testing Approach

A multiple testing procedure for examining the assumption of normality that is often made in analyses of incomplete data sets is outlined. The method is concerned with testing normality within each missingness pattern and arriving at an overall statement about normality using the available data. The approach is readily applied in empirical research with missing data using the popular software Mplus, Stata, and R. The procedure can be used to ascertain a main assumption underlying frequent applications of maximum likelihood in incomplete data modeling with continuous outcomes. The discussed approach is illustrated with numerical examples.