大型数据库交叉型数据鲁棒性挖掘模型仿真

在大型流媒体数据库数据集中,交叉性数据的鲁棒性挖掘结构建立是实现对数据库差异属性分类和数据访问的基础。传统方法对大型数据库中的交叉性数据的鲁棒性挖掘结构建模采用基于遗传算法的数据集聚调度方法,存在较大的路径损耗,数据挖掘的鲁棒性不好。提出改进的基于局部离群点检测遗传进化的大型数据库交叉型数据挖掘模型,构建基于遗传算法的大型流媒体数据库挖掘结构,进行大型流媒体数据库中交叉型数据信息流特征预处理,结合交叉性型数据的离群因子概念,调整流媒体数据调度的位置变换策略,实现交叉性数据的鲁棒性挖掘算法改进。仿真实验结果表明,该算法能有效数据挖掘的a最大匹配率和局部离群点检测性能,保证了数据挖掘的鲁棒性,各项参数指标优于传统方法,展示了较好的应用价值。     

Writing and pseudo‐writing from Internet‐based sources: implications for learning and assessment

In recent years, plagiarism has been on the increase across the Western world. This article identifies Internet access as a contributory cause of this trend and addresses the implications of readily available Internet sources for the teaching and assessment of writing in schools. The basis for the article is a previous study showing a wide incidence of plagiarism in the Internet‐based writing of students in three classes at upper secondary school level in Norway. I relate the students' choices to writing as a cognitive process and as a cultural practice. My basic assumption is that the students' writing is work. It is this work we have in mind when we relate writing to learning and when we assess students' skills on the basis of their written texts. Access to the Internet changes the premises for this work because writing can be replaced by ‘pseudo‐writing’. ‘Pseudo‐writing’ is a work reducing writing practice, which neither excludes nor coincides with what we traditionally associate with plagiarism in schools. The main point in this article is that when students have access to the Internet during essay writing, the result is unavoidably a product of both writing and pseudo‐writing. Internet access thus leads to greater uncertainty about the role writing plays in student learning and makes it more difficult to take written assignments into account in assessing students' school results and effort.     

差错能成为创新之源吗——基于差错管理文化对员工创造力影响的跨层次分析

在面临社会经济转型的关键时期,如何有效激发员工的创造力已成为我国现阶段企业中人力资源管理者的重要课题。以问卷调查的方式获取了安徽省境内43家企业531名员工的有效数据,构建了组织层面的差错管理文化对个体层面员工创造力和创造力自我效能感影响的跨层次中介效应模型,并运用多层线性模型技术对其进行了深入的分析。研究结果表明:组织差错管理文化对员工创造力产生正向的跨层次影响,且创造力自我效能感在组织差错管理文化和员工创造力之间起到部分中介作用。     

侧切和急停起跳对篮球运动员前交叉韧带运动生物力学特征的影响

目的:前交叉韧带断裂是体育运动中最常见的、严重的、治疗康复费高的膝关节运动损伤之一。研究目的是确定侧切和急停起跳动作对前交叉韧带运动生物力学特征的影响。方法:对男女各25名年龄在18~22岁的篮球运动员完成侧切和急停起跳动作时的下肢三维运动学、动力学和表面肌电特征进行采集和处理。运用2×2混合设计的双因素方差分析(ANOVA)对特征参数进行数理统计。结果:动作和性别对下肢水平向后地面反作用力、膝关节外翻力矩、膝关节内旋力矩、腘绳肌群肌电和压力中心到踝关节中心的水平距离具有显著性交互作用。结论与建议:所有篮球运动员完成侧切比急停起跳时膝关节伸膝力矩增加,这些差异使侧切动作发生ACL损伤的可能性更大。另外,仅男性篮球运动员进行侧切动作时更倾向于采用足跟着地方式、外翻力矩以及腘绳肌肌电更大。与男性相比,女性篮球运动员可能更容易导致ACL负荷增大。此外,在完成急停起跳动作中,男性篮球运动员比女性倾向于足尖着地且水平向后地面反作用力小。研究结果提示了在制定预防ACL损伤训练方案时,应根据不同动作和性别针对性地设计训练方式。     

0Cr18Ni9不锈钢车削力试验研究

切削力是切削加工中的一种伴随现象,切削力的大小直接影响到刀具寿命、加工质量和加工效率。在分析车削力时域特征的基础上,通过0Cr18Ni9不锈钢的正交车削试验,研究了切削参数对切削力波动系数的影响规律。结果表明：动态性是车削力的基本属性,切向分力和进给分力是车削力的主要成分;切削用量三要素中,切削深度ap对进给分力波动系数Qf和切向分力波动系数Qc都有着显著的影响,两者随ap的变化趋势基本一致。     

晚清对外观念中的变与不变

第一次鸦片战争后,清朝上下保持一贯的＂华夷观念＂,将鸦片战争的失败合理化为＂招抚＂夷人的结果,而不顾国力强弱的对比。面对第二次鸦片战争再次战败的结果,统治者被迫接受彼强此弱的现实,调整观念中的＂华＂、＂夷＂区隔,对外采取注重信义的＂和戎外交＂政策。而在观念的最末处,仍保留着一块修护尊严的居所。     

Using game‐based learning to support struggling readers at home

Significant numbers of children (6% of 11‐year‐olds) have difficulties learning to read. Meanwhile, children who receive appropriate support from their parents do better in literacy than those who do not. This study uses a case study approach to investigate how digital games designed to support struggling readers in school were used at home, by the parents of six children to support their children’s literacy. Mostly, the children enjoyed playing the games and believe that it helped improve their reading. The parents all valued the opportunity to participate in their child’s learning and believe that the games’ approach to learning is effective. The study considers key influences on the successful use of games to support struggling readers (repetition, feedback, motivation, self‐efficacy, parental beliefs) and raises questions, further consideration of which might usefully inform the future development of effective game‐based learning.     

Using the multimodal affordances of the interactive whiteboard to support students’ understanding of texts

The purpose of the study reported on here was to explore ways in which the interactive whiteboard (IWB) can support students’ understanding of texts. A Year 3 and a Year 4 primary school class in New South Wales, Australia, is the focus of the research. A qualitative case study was carried out using multimodal analysis focusing on the use of an e‐book displayed via the IWB. The results of the study indicate that the IWB can support students’ understanding of a narrative to prepare them to write a whole‐class response through providing increased access to a range of resources that are multimodal in nature. The way the interactive features of the IWB can facilitate access to multimodal resources to cater for student needs is also discussed.