Teaching as Theater

As new media proliferate, professors need to be particularly attentive to the ways by which students learn—in and out of the classroom—and how scarce classroom time can be organized. This article argues that professors' comparative advantage lies as an exemplar of discipline‐based thinking. Effective training in how to think about problems (the essence of any discipline) demands that professors embrace the classroom as theater, where business drama and the story it tells can capture the hearts and minds of the student participants. The article talks through a case as theater.     

浅谈强化集团企业资金结算中心的现金流量管理

资金结算中心是代表企业集团母公司进行资金管理的内部职能部门,它代表集团筹措协调规划和调控整个集团的现金流,而现金流支撑企业集团的生存与发展,本文试从企业所处发展周期的不同以及财务报告等不同角度分析集团企业资金结算中心的现金流量,提出了几点有针对性的控制措施强化集团企业资金结算中心的现金流量管理.     

车载式施肥机肥量控制系统的性能探讨

通过对步进电机加螺旋装置、电液伺服系统、电动推杆、直流比例电磁铁和步进液压缸五种控制系统进行比较,电液伺服系统简便易行,控制精度高,响应速度快,使用寿命长,成本相对较低,适合在农业生产中推广应用。     

Crowdsourcing mode-based learning activity flow approach to promote subject ontology generation and evolution in learning

ABSTRACT

Subject ontology can help implement the structured organization of knowledge for online learners and thus plays an important role in the learning process. However, building ontologies by experts is time-consuming, and the adaptation of such ontologies to different contexts might be a problem. Crowdsourcing, which allows users to build and refine ontologies during their learning process, has exhibited potential for solving this problem. In this study, a crowdsourcing mode-based learning activity flow approach is proposed to guide the learning of online learners while promoting the generation and evolution of subject ontologies using the learners’ contributions to the learning content. This flow makes full use of the learners’ wisdom during the learning process to promote self-regulated learning as well as the generation and evolution of the ontology. Based on the proposed approach, a learning support system was developed and an experiment conducted involving a Chinese lesson on “The Liangzhou Poem”. In the experiment, student participants built 722 triples, of which 584 evolved as formal items in the subject ontology. Moreover, all learners were able to construct a well-organized knowledge graph. Students in both high- and low-scoring groups contributed valuably to the knowledge generation and evolution of the subject ontology. Furthermore, while the widths of the knowledge constructed by students in high- and low-scoring groups were similar, their depths were substantially different. During this process, the crowdsourcing-based activity flow system achieved satisfactory technique acceptance, which means that the proposed approach and system are useful for the effective generation of subject ontologies while helping learners acquire knowledge.     

一类二阶变系数线性微分方程的解法

研究了利用常数变易法求一类二阶变系数线性微分方程通解的解法,给出通解公式.     

基于全局鲁棒滑模控制的变速恒频双馈风力发电机的研究

随着风力发电技术的发展,对变速恒频双馈风力发电机的控制方法方面的研究显得越发的重要.根据变速恒频双馈发电机对控制系统要求响应速度快、鲁棒性强的特点,将矢量转换方法与全局滑模控制方法结合,提出了一种全局鲁棒滑模变结构控制方案.针对双馈异步电机在内部参数变化和外部风机负载转矩扰动共同带来的扰动进行设计,并对比了传统PI控制.仿真证明,该控制方法可以提高双馈电机的动态性能,进一步增强了电机的抗干扰性.     

基于OPNET的流媒体应用流量特征分析

针对不同工作模式的流媒体应用数据流,根据报文大小、IP地址和端口识别出流媒体应用有效数据,分析了流媒体应用流量包的大小、数量和报文长度分布等特征.利用OPNET对不同模式的流媒体流量特征数据进行分析,提取多种流行流媒体应用的行为特征.     

教师定期流动政策执行的实证调查研究——基于政策工具视角

通过问卷调查对教师定期流动政策的执行过程进行实证研究,以政策工具理论为指导,基于政策工具视角对政策执行过程的实证调查进行分析与讨论.在优化政策工具方面从完善其管理环境、制度环境、监督环境着手,探索将政策意图转变为管理行为、将政策理想转变为政策现实的最佳工具,尤其是2011年重庆市《义务教育条例》颁布并逐步推行后,更需寻求使现有教师流动机制更高效、更完善、更有效的工具路径.     

Bilateral teleoperation with reducing wave-based reflections

This paper presents a wave-based bilateral teleoperation structure to reduce the wave reflection and enhance the force and speed tracking performance through adjusting the relative parameters. A time domain passive approach is also applied to deal with the passivity of whole system even with non passive environment. The efficiency of the proposed method is confirmed by some experimental results.     

气流能量方程及其应用

用流体运动微分方程建立能量方程,讨论绝热压缩气流能量方程及应用,并对低速气流按不可压缩流体计算所产生的误差进行了分析.