Characterization of surface EMG signals using improved approximate entropy     

Chen WT  Wang ZZ  Ren XM 《Journal of Zhejiang University. Science. B》2006,7(10):844-848

An improved approximate entropy （ApEn） is presented and applied to characterize surface electromyography （sEMG） signals. In most previous experiments using nonlinear dynamic analysis, this certain processing was often confronted with the problem of insufficient data points and noisy circumstances, which led to unsatisfactory results. Compared with fractal dimension as well as the standard ApEn, the improved ApEn can extract information underlying sEMG signals more efficiently and accurately. The method introduced here can also be applied to other medium-sized and noisy physiological signals.  相似文献   

Exploring the temporal dimension of forum participation in MOOCs     

Hengtao Tang  Bo Pei 《Distance Education》2018,39(3):353-372

Discussion forums are increasingly central to massive open online courses (MOOCs), and it is vital for learners to participate in associated forum activities. Active forum participation positively relates to learner achievement in that more posts yield better learner performance. However, this numerically aggregated measure overlooks the fact that longitudinal trajectories of forum participation temporally vary among learners with different motivations in taking MOOCs. To provide timely support for learners to stay engaged, it is important to understand the temporal variation of longitudinal forum participation and how different motivations account for the variance. Using educational data mining techniques, this research identified three clusters with different longitudinal participation trajectories and also indicated that intrinsically motivated learners outperformed others in their longitudinal forum engagement. Also, examining longitudinal forum participation more accurately differentiated learner performance than the numerically aggregated measure. Last, learners persistently engaging in forums were more likely to perform better in MOOCs.  相似文献   

社交网络情境下社会资本影响知识共享的效果分析     

曹玲  顾兵光 《现代情报》2018,38(2):41-47

经过前人的不断研究和摸索,目前,我们通常将社会资本划分为3个维度：认知维度、结构维度和关系维度,结合问卷调查获取的数据开展相关性和回归分析。结果显示,社会资本的3个维度在知识共享的质量效果和数量上均产生了较大的正面影响：从知识共享的质量效果的角度来看,正面影响的因素有3个：1）认知维度中的共同愿景和语言;2）结构维度的中心性;3）关系维度中的社区信任和认可;从知识共享的数据的角度来看,产生显著影响的因素有认知维度中的共同的愿景和语言和关系维度中的社区信任和认可。  相似文献   

可持续发展理论:概念演变、维度与展望   总被引：4，自引：0，他引：4  

张晓玲 《中国科学院院刊》2018,33(1):10-19

"可持续发展"不能仅以代际公平的方式来定义,而应注重国际公平。文章通过追溯相关文献,梳理了"可持续发展"概念的演变过程,明确了其在人类需求和自然供应能力之间的沟通价值,并结合多种经济学原理加以论证。研究发现,"可持续发展"的概念仍然是模糊的,尤其缺乏对空间维度的"先验性"思考。为解决这一问题,文章将"层级空间"的平等维度引入"可持续发展"。并进一步引进了"可持续发展科学"的概念,提出了一系列关于可持续发展的核心问题及其研究策略,以期为推动该领域在国内的发展作出贡献。  相似文献   

一维卷积求导在电位滴定中的应用     

曾泽曹冬梅  由业诚郭明 《大连大学学报》1999,20(6):63-65

本文采用一维卷积求导方法,对电位滴定曲线进行处理,滤除了滴定中的噪声干扰,克服引入的随机误差,通过简单计算,精确确定终点．  相似文献   

价值话语下的民族精神解读     

李喆 《华中科技大学学报(社会科学版)》2006,20(1):13-17

民族精神是一个归属于价值维度的概念,由于其仍处于一个不确定的话题,根据学科特点,它在目前理当更是价值哲学研讨的对象。民族精神由民众的终极价值取向与民众的世俗价值取向这两个层面共同作用形成,其形成之后亦反过来对民众的价值追求产生影响,所以要适时进行价值调适,以利于民族精神良性地服务于民众的价值追求。  相似文献   

Indeed,sometimes knowledge does not help: A replication study     

Stark  Robin  Gruber  Hans  Mandl  Heinz  Renkl  Alexander 《Instructional Science》1998,26(5):391-407

In an earlier study we found that intermediate experts in the domain of economics did not surpass novices in complex learning and knowledge application with a computer-based business simulation. In the present study, it was investigated whether these contra-intuitive findings can be replicated. In order to scrutinize the reasons which led to these findings, some parameters of the learning environment were changed. The duration of the exploration phase and of the problem-solving phase as well as the complexity of the situations were increased, motivation and acquired declarative knowledge were assessed. In view of mastering recurring demands and the functionality of mental models, no differences were found between a group of novices (15 students of humanities with a supplementary training in economics) and a group of intermediate experts (13 advanced students of economics). The findings of the original study were replicated, motivation had no effect on the result. In terms of declarative knowledge, the novices turned out to be even better.  相似文献   

厨房家具设计中的尺寸与布局研究     

韩春明  杨志发  杨丽丽 《中国科技信息》2010,(3):187-188

厨房家具的种类繁多、样式丰富、功能各异．它随着人类生活习惯的演变而不断的变化着。作为约束厨房家具的两个重要拳数,尺寸和布局在厨房的设计过程中理所当然地被设计师所考虑到。本文从这两个基本方面出发,分析了厨房家具设计与尺寸、布局的关系．初步探讨了从哪些方面获得合理的尺寸与布局,为厨房家具的设计提供了一定的参考。  相似文献   

人格维度与青少年的体育锻炼     

赵树东 《搏击·武术科学》2009,(4)

文章通过对外倾-内倾、神经质-稳定性、精神质-超我机能的三种不同人格维度进行分析,对青少年生理、认知、社会性和智力发展特点进行了解,从而为推动体育锻炼在不同人格维度的青少年间的推广提供可借鉴的理论依据。  相似文献   

10年来我国高等教育理论研究的趋势分析——一种结构式的定量研究   总被引：1，自引：0，他引：1  

康翠萍  王刚  石敏 《大学教育科学》2007,5(5):31-41

运用结构式定量研究方法,对我国1996～2005年的高等教育学理论文献,从文章题目、作者、摘要、关键词、课题、问题的提出、重要术语界定、研究方法、结论、参考文献或注释等10个维度进行评价和分析.研究结果表明:10年来我国高等教育学的研究水平有了很大提高,理论水平不断提升,学术规范正逐步形成和确立.  相似文献