一种快速的自适应预失真算法

研究了一种快速有效的算法用来加快预失真算法的收敛速度,即线性迭代法。并通过计算机仿真来验证这种方法的有效性和可行性,通过计算机的仿真可以使三阶交调分量抑制大概15个dB。理论分析和仿真结果可以表明,该算法使功率放大器的线性化得到很好的改善。     

基于NS-2的距离向量选路算法仿真

路由协议是计算机网络组网的关键技术和教学难点,距离向量的选路算法对计算机网络初学者来说更加抽象.通过NSG脚本生成工具可以方便快捷的建立NS-2网络模拟器的仿真场景来仿真距离向量选路算法,运行时可直接观察到实际计算机网络节点动态交换路由信息、建立路由表和数据传送的过程,同时trace文件记录了仿真过程中节点交换的信息包及其传送时间.     

第三代短波网络自适应多址接入算法的研究

设计一种基于第三代短波链路自动建立（3G—ALE）技术的自适应多址接入算法。文中分析3G—ALE基本多址接入算法及改进型算渚的缺点,设计依据业务长、短不同而进行自适应接入的TA—CSMA算法,建立网络模型进行计算机仿真验证。仿真结果表明,TA—CSMA算法可以使网络呼损率及信道占用率明显降低,使网络吞吐量有较大提高。TA—CSMA算法是适合短波自组织网络的一种高效的多址接入协议。     

计算机仿真在运筹学优化算法教学中的应用——以偏粒子群算法为例

以运筹学的优化算法知识点教学为例,介绍计算机仿真技术在课程教学、可视化展示中的应用。在运筹学课程体系中,优化算法的教学由于其较为复杂的计算公式或计算过程,相对较多的优化思想而难以深入。为了解决这一教学实践中出现的困境,探索采用非常直观地教学手段—计算机仿真教学方法,通过计算机演示配合课堂教学,给学生一个相对容易接受的教学体验。通过优化算法中具有代表性的偏粒子群算法为例,详细描述了教学目标、教学内容等细节,重点介绍了计算机仿真的教学过程。鉴于计算机仿真方法在课程教学中的特色之处,通过优化算法教学实践探索,为相似的本科教学内容和知识点的教学提供了范式。     

轴系结构设计实验的改革与创新

介绍了轴系结构设计实验的实验装置和实验内容安排。将计算机三维动态仿真与零部件实物模块结合起来,使学生通过该实验,可以熟悉和掌握轴的结构设计、轴承组合结构设计的基本要领,并通过计算机三维动态仿真实现轴系结构的创新设计。达到培养学生创新意识,提高工程实践能力的目的。     

三角形与三角形相交测试的改进算法

在研究了三角形与三角形相交测试的原理和算法的基础上,提出了三角形的改进算法,通过计算机仿真验证了该算法的可行性,提高了检测的效率.     

基于OPNET Modeler的计算机网络仿真实验教学研究

网络仿真软件OPNET以友好的界面,相对短的上手时间以及高校优惠的价格,吸引了大量的网络研究人员,尤其是高校师生。运用OPNET Modeler软件在“计算机网络”的实验教学中开展仿真实验,丰富了实验教学手段,使网络的分析和设计得到简化,并且可以使学生获得对网络的工作原理与操作方法的感性认识。对OPNET作了简单介绍,并通过一个OPNET Modeler仿真实验实例说明在“计算机网络”实验教学中适当地运用仿真技术,可以获得较好的教学效果。     

基于Matlab的线性调频Z变换算法仿真

线性调频Z变换(CZT)是一种比快速傅里叶变换(FFT)更有效计算信号频谱的算法。针对CZT理论性强,不易理解和掌握的特点,基于Matlab GUI功能设计了线性调频Z变换算法仿真界面,包括算法的计算路径、3种典型序列的线性调频Z变换、线性调频Z变换算法中涉及的中间序列,以及3种典型序列的快速傅里叶变换。通过对CZT和FFT仿真结果的对比,可以直观理解CZT更加灵活的特点;通过对算法计算路径的仿真和算法中涉及的中间序列的仿真,使学生更容易理解和掌握CZT算法原理,进而提高教学效果。     

《输入、输出语句和赋值语句》教学设计

1 内容和内容解析要完整地认识算法,就必须学习算法程序,而算法程序是由基本算法语句组成的,因此学习基本算法语句是编写算法程序的基础。为了使算法在计算机上实现,还需将自然语言和程序框图转变成计算机能够理解的程序语言,可以说,用算法语句描述算法是用计算机解决问题的前提条件。程序语言的种类很多,但各种程序语言中基本     

基于硬件在环仿真的交通信号控制实验设计

为使学生能够直观体验交通信号控制实验的效果,设计了由计算机(运行微观交通仿真软件)、信号控制机和信号机接口设备组成的硬件在环仿真实验平台。通过该仿真实验平台,学生可以设置信号机参数、运行仿真实验、观察信号机对交通流的控制效果并进行离线评价、比较不同交通条件下信号控制方案的优劣。通过该实验,可以提高信号控制实验的教学效果和学生解决实际交通问题的综合能力。     

Little room for capacitation: rethinking Bourdieu on pedagogy as symbolic violence

In Bourdieu’s early work on education, he declares that ‘All pedagogic action (PA) is objectively symbolic violence insofar as it is the imposition of a cultural arbitrary by an arbitrary power’. This article rethinks Bourdieu’s proposition. It questions whether all PA is symbolic violence and the very notion of a cultural arbitrary upon which this view is based. For Bourdieu, culture is framed narrowly in terms of class, and pedagogy a mechanism by which it is reproduced. As such, it functions as a form of violence having much in common with Foucault’s notion of discipline. Unlike Foucault, however, who also acknowledges the enabling potential of power as a technology of the self, Bourdieu has no such equivalent. His concept of PA leaves little room for capacitation wherein, rather than a cultural arbitrary, certain skills can be seen to have an inherent use value equipping individuals with capacities that are a means for social transformation.     

Promoting self-regulated learning through portfolio assessment: testimony and recommendations

Portfolio assessment (PA) has been extensively adopted for writing development in the past three decades. Much research on PA primarily investigates students’ and teachers’ perceptions of its benefits, and how it influences students’ motivation and general writing abilities. Despite its purported effectiveness, not much has been done to understand the relationship between PA and self-regulated learning (SRL) especially in English as a Foreign Language (EFL) or English as a Second Language (ESL) writing research. This paper contends that PA can productively foster SRL in EFL writing classrooms, and, more specifically, it develops a conceptual model of SRL within the context of writing portfolios and iterative feedback processes. Supporting evidence emphasising how PA can facilitate SRL is discussed and evaluated. The paper ends with six recommendations and implications proposing how SRL can be promulgated in EFL portfolio-based contexts. Finally, possible future research is suggested.     

The necessity of the alphabetic principle to phonemic awareness instruction

This investigation examined the extent to whichcurricular choice and incorporation of phonemicawareness (PA) into the kindergarten curriculumaffects growth in kindergarten literacy skillsand first-grade reading and spelling outcomesin 114 classrooms in 32 Title 1 schools for4,872 children (85% African American). Literacy curricula were described as havingmore or less teacher choice and more or less PAand were implemented with ongoing professionaldevelopment. Observations of curriculumfidelities and ratings of student behavior werealso obtained. Alphabetic instruction withoutPA was not as effective as alphabeticinstruction with PA. However, effectiveinstruction in PA and alphabetic codingappeared to be as much a consequence of ongoingprofessional development as it was a functionof prescribed PA activities. Results providelarge-scale classroom support for findings onPA reported by the National Reading Panel[(2000). Teaching children to read: An evidence-basedassessment of the scientific research literature onreading and its implications for reading instruction.Washington, DC: National Institute of Child Health andHuman Development].     

Two portfolio systems: EFL students’ perceptions of writing ability,text improvement,and feedback

Research into portfolio assessment (‘PA’) typically describes teachers’ development and implementation of different portfolio models in their respective teaching contexts, however, not much attention is paid to student perceptions of the portfolio approach or its impact on the learning of writing. To this end, this study aims to investigate how two groups of Hong Kong EFL pre-university students (Groups A and B) perceived and responded to two portfolio systems (with each group experiencing one portfolio system either working portfolio or showcase portfolio) in one academic writing course. The case study approach was adopted and data sources included semi-structured interviews, student reflective journals, classroom observations, and analysis of text revisions. Findings indicated that students from the showcase portfolio group (Group B) were less enthusiastic about the effectiveness of PA, and queried whether it could promote autonomy in writing, while the working portfolio group (Group A) was more receptive to the experience, and considered that a feedback-rich environment in the working portfolio system could facilitate writing improvement. The paper concludes with a discussion of how PA can be used to promote self-regulation in the learning of writing.     

Effects of self-assessment and peer-assessment interventions on academic performance: A meta-analysis

This meta-analysis examined the effects of self-assessment (SA) and/or peer-assessment (PA) interventions on academic performance. The synthesis included 626 effect sizes from 175 independent studies, either using an experimental/quasi-experimental design or a repeated measures design, and involved 19,383 participants in total. Results indicated that SA (g = 0.585), PA (g = 0.606), and SA + PA (mixed) intervention (g = 0.448) had meaningful effects on academic performance. The difference between the effects of SA and PA interventions, conducted on different groups within the same study, was not statistically significant. The use of online technology increased the effect of PA interventions but not for SA. Participants with a higher mean age had more performance gains from the SA + PA (mixed) intervention. For both SA and PA, the studies that used a repeated measures design generated larger effect sizes than those with an experimental/quasi-experimental design. Overall, the findings from this meta-analysis demonstrated the benefits of SA and PA interventions on academic performance in different contexts. Implications for practice and directions for future research are discussed.     

Phytate： impact on environment and human nutrition. A challenge for molecular breeding

Phytic acid (PA) is the primary storage compound of phosphorus in seeds accounting for up to 80% of the total seed phosphorus and contributing as much as 1.5% to the seed dry weight. The negatively charged phosphate in PA strongly binds to metallic cations of Ca, Fe, K, Mg, Mn and Zn making them insoluble and thus unavailable as nutritional factors. Phytate mainly accumulates in protein storage vacuoles as globoids, predominantly located in the aleurone layer (wheat, barley and rice) or in the embryo (maize). During germination, phytate is hydrolysed by endogenous phytase(s) and other phosphatases to release phosphate, inositol and micronutrients to support the emerging seedling. PA and its derivatives are also implicated in RNA export, DNA repair, signalling, endocytosis and cell vesicular trafficking. Our recent studies on purification of phytate globoids, their mineral composition and dephytinization by wheat phytase will be discussed. Biochemical data for purified and characterized phytases isolated from more than 23 plant species are presented, the dephosphorylation pathways of phytic acid by different classes of phytases are compared, and the application of phytase in food and feed is discussed. Project supported by the Danish Agency for Science, Technology and Innovation, Copenhagen, Denmark and HarvestPlus     

The effects of contingency avoidance on programmed student achievement

If it is assumed that student failure in the classroom situation is the result of inadequate performance skills rather than a lack of ability, then the attention of the educator should more properly be directed at teaching the student to develop effective methods of studying. The present experiment employed a Programmed Student Achievement (PA) procedure which required that the student evidence 100% mastery of discrete units of material. Two PA contingencies which differed in the intensity of the consequence of failing to evidence mastery were used, testing the hypothesis that the PA effect is analogous to avoidance conditioning. In addition, generalization of the effect of PA on performance in courses taken concurrently was evaluated. The performance of PA students was found to be significantly superior to that of control students on both weekly quizzes and major exams; however, performance under the two experimental contingencies did not differ. Additionally, the PA effect did not generalize to performance in other courses. The implication of these data for an avoidance hypothesis account of the PA effect is discussed.     

网络技术给学校教育带来的负面影响研究

众所周知，网络技术对教育的贡献是巨大的，大多数教育工作者比较注重网络技术对学校教育的正面研究，而忽略了对它负面作用的研究。因此，文章从学校教育的视角来探讨网络技术带来的负面作用，对于技术高度发展的今天更为重要，正视存在的问题，对学校教育会有不容忽视的理论价值和实践意义。     

The Lantern on the Road of Life

<正>Nowadays,with the booming of the economy and the development of the technology,people’s living standard has been improving remarkablely.The colorful daily activities add much spice to our life,there are so many different and interesting things that we can do in all aspects of our life.But,there is a serious disadvantage of it which is becoming more and more obvious,our purpose now is becoming more and more uncertain imperceptibly.Addison said,"Every man should have a purpose in life.     

一种远程无线身份认证装置

本装置是综合运用3G技术、指纹识别技术和嵌入式技术等研发的一种远程无线身份认证系统。用3G通信方式可以不受位置的限制,比Internet方式更灵活,且3G带宽比普通的RJ45接口网络连接速度更快。本装置成本低廉,安全可靠,实用性强,具有广泛的应用和推广价值。