企业中Exchange2003信息化管理的应用

针对于现今企业的信息交流的需要进行了分析研究,提出了在Windows2003 Server系统平台下使用Exchange 2003邮件软件和其前端软件Outlook 2003来为企业构建信息管理平台,实现企业中信息交换的电子信息化管理。     

替代性世界：学习环境新方向

教育领域一直以评价和采用交互创新技术为先驱,这些交互创新技术为教育技术专家探索计算机辅助的教学提供了实践的土壤＂。替代性世界＂（Alternative worlds）是完全实时的、高保真的、用户高度介入的学习环境。其特点是具有丰富的环境、丰富的接口、操作驱动和有效应用于教与学＂。替代性世界＂在混合式学习中可以冲破传统教育屏障,拓展教师和学习者角色,为学习者提供时间和空间的便利,实现终身学习＂。替代性世界＂学习环境是一个新的研究领域,它为专注于人机交互、社会网络和虚拟现实的教育技术专家开拓了新方向和新空间。     

Activating the curriculum: a socio-ecological action research frame for health and physical education

The health and physical education (HPE) profession needs to find alternatives to its individualistic and performative focus if it is to remain relevant and meaningful for all learners. This paper presents a way of framing HPE that helps to shift the focus from the individual as autonomous decision-maker, and goes beyond sport and fitness testing as the main contexts for learning. To do this we present the socio-ecological action research (SEAR) frame for unit development that was co-created and enacted over a six-month period involving dialogue between teachers, students, parents, researchers and community. This paper presents findings from semi-structured interviews, student artefacts and field notes collected as one component of a broader three-phase study which spanned three years. The data describe how generalist primary teachers (n=4) from a small Victorian community and their students (aged 8–10 years) tackled a unit of work that positioned centrally the everyday physical experiences of active school travel (AST). Teachers supported students in exploring barriers to their AST, and developing strategies that would counteract some of the negative perceptions that had limited their AST in the past. The findings suggest that the unit of work evolved from an exploration of AST into a much broader exploration of the whole community. This paper does not provide evidence for an alternative way to view HPE, rather it represents an embryonic exploration of how a SEAR frame might support teachers in applying inquiry-based pedagogies that extend beyond the individual as autonomous decision-maker, and promote opportunities for exploration and understanding of environmental, social and personal factors that influence our health and everyday physically active lives. Despite students being positioned as central actors within the SEAR frame, obtaining genuine student voice throughout the process proved challenging.     

Do students learn what they teach when generating teaching materials for others? A meta-analysis through the lens of learning by teaching

Students can generate teaching materials for others. However, solid evidence of the learning effect for the student creating the material is needed. This meta-analysis aims to explore current evidence of the learning-by-teaching potential effect on students’ learning of the content they teach. A total of 23 articles were included in the meta-analysis, providing 62 comparisons between an intervention in which students were required to create a teaching material and an alternative condition. Possible moderators were examined as well (i.e., product, educational level, content area, and access to source material). Results show statistically significant differences in favour of creating teaching materials when compared to business-as-usual or alternative interventions, with an overall effect of 0.17. However, the type of product and the access to source material significantly moderate the findings. Audio-visual and visual materials considerably outperform textual materials. Having no access to the source material is better than having full access to it. No publication bias was detected. However, the type of control group moderates the findings: creating teaching materials shows a significant effect when compared to nonbeneficial interventions rather than to other expected beneficial interventions. Nonbeneficial interventions refer to business-as-usual or alternative interventions that are not expected to influence the outcome much, while beneficial interventions are those that are known or expected to have a positive effect. The findings are discussed based on the different views on the underlying learning-by-teaching mechanisms. Limitations as well as implications for practice, policy, and future research are underlined.     

AFE变频器在船舶电力推进电机控制中的应用

为有效改善船舶电力推进系统电能质量和能量反馈,将有源前端(Active Front End,AFE)变频器应用于船舶电力推进电机控制.根据船舶电力推进系统的特点,选择基于电流内环前馈解耦控制的直接电流控制方法,并对AFE变频器的独立控制和联合控制方式进行研究.用MATLAB/Simulink对这两种方式进行仿真.分析仿真结果,得出这两种控制方式分别适应的电力推进船舶类型.     

Introductory statistics in the garden

This article describes four semesters of introductory statistics courses that incorporate service learning and gardening into the curriculum with applications of the binomial distribution, least squares regression and hypothesis testing. The activities span multiple semesters and are iterative in nature.     

Engineering students’ experiences of interactive teaching in calculus

This study reports on an educational development initiative where peer instruction was used instead of traditional lectures in a calculus course for first-year engineering students. The aim of the study was to explore students’ experiences of this method. Data were collected by means of an open-ended questionnaire on two occasions: early and late in the course. The data were analyzed with an inductive content analysis. The findings comprise three qualitatively different ways to experience the interactive teaching method in calculus: (1) enthusiasm, (2) nuanced skepticism and (3) aversion. The categories differed regarding emotional reactions to the teaching, experiences of learning, conceptions of teaching and learning, and experiences of meaningfulness. Many students expressed enthusiasm for learning with peer instruction and noted that the method gave both teachers and students feedback on what students have difficulties with. These students perceived that they were responsible for their own learning. Other students experienced that peer instruction had some advantages and disadvantages, and preferred a mix between traditional lectures and peer instruction sessions. They seemed to believe that teachers and students share responsibility for learning. Some students expressed an aversion for peer instruction and the method seemed to challenge their beliefs of how teaching and learning is best conducted. Our study illustrates that educational development initiatives, even though based on research on student learning, do not benefit all students. One of the major obstacles seems to be that students’ underlying beliefs regarding teaching and learning may be counterproductive to the ideas behind the educational initiative. We suggest that beliefs regarding teaching and learning need to be addressed when introducing new teaching and learning methods.     

Manipulating cognitive engagement in preparation-to-collaborate tasks and the effects on learning

While collaborating with a peer can be highly beneficial for learning, more work is needed to understand how instructional activities in collaborative contexts should be designed so as to maximize learning outcomes. To address this, we investigated the impact of different types of preparatory and cognitively engaging tasks on learning from collaborating, using a 2 × 2 experimental study conducted in situ in four introductory psychology classes. We compared individual preparation versus no-preparation and “active” versus “constructive” tasks. A dyadic multilevel analysis showed that preparation prior to collaborating led to better deep learning outcomes, but that the type of preparation did not have a significant effect. We include an exploratory analysis of student dialogues during collaboration to further interpret our findings. We propose that a cognitively engaging preparation phase may lead to better learning because it encourages students to collaborate constructively even when the type of task does not elicit such engagement.     

主动进气格栅技术研究

随着主动进气格栅技术在汽车上的逐步使用,主动进气格栅的技术优势逐步体现,文章阐述了主动进气格栅对整车行驶阻力的优化和整车热控制的相关影响,并以线性回归模型的方法对主动进气格栅的标定方法进行了初步探索。     

Sliding mode control for active magnetic bearing system with flexible rotor

This paper presents the analysis and control of active magnetic bearing (AMB) systems with a flexible rotor. A sliding mode controller design scheme is proposed to compensate for the nonlinear effects of the AMB system. A nonlinear model of the AMB system with an electromagnetic actuator and a flexible rotor is proposed to facilitate the present system analysis and controller design. This nonlinear model takes into account the dynamics of the flexible rotor, the characteristics of the nonlinear electromagnetic suspended system, and the contact force between the auxiliary bearing and the shaft. This study also considers the auto-centering control of the AMB system when subjected to disturbances and variations in the system parameters. The numerical results show that the system exhibits a periodic motion and demonstrates high accuracy and robustness when operating under sliding mode control.