Teaching-Material Design Center: An ontology-based system for customizing reusable e-materials

Use of electronic teaching materials (e-material) to support teaching is a trend. e-Material design is therefore an important issue. Currently, most e-material providers offer a package of solutions for different purposes. However, not all teachers and learners need everything from a single package. A preferable alternative is to find useful material from different packages and combine them for a particular course. Currently, most educators collect the material manually, which is time-consuming and may result in missed material. In this paper, we describe a system – the Teaching-Material Design Center, which follows the standard of Sharable Content Object Reference Model – to separate e-material for use as teaching templates and learning objects and to label the material with use of semantic metadata for searching. This system can find existing teaching templates and learning objects for e-material designers and provide a convenient environment for constructing customized e-material for different requirements. We describe the implementation and evaluation of the proposed system for a course. Our system is efficient in finding teaching templates and learning objects and shortening the e-material development process.     

All updateable objects in working memory are updated whenever any of them are modified: Evidence from the memory updating paradigm.

In a series of experiments, participants were required to keep track of 1 or 2 working memory (WM) objects, having to update their values in 80% of the trials. Updating cost, defined as the difference between update and non-update trials, was larger when 2 objects were involved compared with when there was only 1 object was involved. This finding was interpreted as evidence that the updating process encompasses both objects in WM, even though only 1 of them is actually updated. This feature of WM updating is limited to objects defined as "updateable," throughout the trial sequence. The results are explained by the need to reprogram the phonological loop when updating or the need for desynchronization followed by resynchronization of WM contents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

用介孔材料制备定向碳纳米管的研究进展

综述了近年来采用介孔材料制备定向碳纳米管的研究进展,包括介孔材料的合成及介孔材料在制备定向碳纳米管方面的应用。重点介绍了采用合成介孔材料的模板剂石墨化及介孔材料作为载体制备定向碳纳米管的方法,探讨了模板剂种类、催化剂的制备方法及反应温度和时间对定向碳纳米管生长的影响和定向碳纳米管生长的介孔限制机理,并提出了这一领域的研究方向。     

Frames of Reference in Mobile Augmented Reality Displays.

In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and the imagined heading and between the actual heading and the imagined heading. The effect of actual-imagined on pointing latency was observed for naive users but not for users with brief training or instructions concerning the fact that objects can move with body movements. The results indicated that naive users used an environment-stabilized reference frame to access information arrays, but with experience and instruction the nature of the representation changed from an environment stabilized to a body stabilized reference frame. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

助模板剂对MCM—41分子筛孔结构和性能的影响

在硅酸钠－硫酸铝－十六烷基三甲基氯化铵－水体系中，加入不同类型，如正庚烷、三甲基苯和十二胺的有机助模板剂（简称助剂）进行ＭＣＭ－４１分子筛的合成试验，并用ＸＲＤ、ＩＲ及Ｎ２吸附等方法考察了助剂对ＭＣＭ－４１分子筛孔径、热稳定性及酸性的影响。结果表明，十二胺助剂对ＭＣＭ－４１分子筛的孔径影响最大，但热稳定性较差，相比之下，三甲基苯助剂合成的ＭＣＭ－４１分子筛具有孔径大、热稳定性好和酸性特征较好的特点。     

Ray-cast volume rendering accelerated by incremental trilinear interpolation and cell templates

Two related ideas for improving the speed of ray-cast volume rendering are studied in this paper. The first is an incremental algorithm for trilinear interpolation, a method commonly used in ray-cast volume rendering to calculate sample values. The incremental algorithm can expedite trilinear interpolation when many samples along a ray are located in one cell. The second is an efficient hybrid volume rendering restricted to parallel projection. In the preprocessing stage, acell template is created to store the information used by the incremental trilinear interpolation. When a cell is parallel projected, the information is retrieved from the template to compute the cell contribution. Because the algorithm with only one template may cause aliasing, an antialiasing technique exploiting multiple cell templates is proposed. With our method, ray-cast volume rendering can be accelerated considerably.     

修正型罗德里格斯参数在旋转弹上的应用

光纤陀螺可应用于旋转弹导航上,以提高其精确打击能力。基于光纤陀螺的捷联惯性导航系统是实现这一目的的重要手段之一。其中,姿态更新算法是捷联惯性导航系统的核心。针对旋转弹短时、近程的特点,提出一种基于修正型罗德里格斯参数的全姿态更新算法,并给出适合旋转弹姿态确定的数学模型。仿真结果表明与传统姿态更新算法相比较,新算法可以更有效的抑制不可交换误差,降低跟随时间的累积误差,减少高动态环境下的计算量,提高算法结算的速度和精度。     

基于模板的．Net三层架构的代码自动生成

三层架构是数据库开发中最常用的分层架构。三层结构能够提高代码重用率,降低项目开发难度。为了解决手工编写三层架构的代码工作量大且容易出错的问题,使用．Net平台提供的动态编译和反射技术,设计并实现了基于可定制模板的自动代码生成器。该代码生成器利用三层架构的代码依赖数据库的架构信息这一特点,以数据库架构信息、Xml配置文件和模板文件作为输入,输出三层架构的各层代码。用户可以修改Xml配置文件的内容和使用该代码生成器提供的模板语言定制、修改自己的模板文件,方便、灵活地控制输出的目标代码。代码生成器的使用在实际的项目开发中具有重要的意义。     

基于Excel模板打印的实现及服务器部署

简要介绍了几种在ASP.NET环境中调用Excel打印报表的方法,针对实际需求,对比几种方法的优缺点,提出了在Web开发中基于Excel模板打印及服务器部署的可行性方案,并给出了相关的实现代码和说明。     

基于小波的实时烟雾检测*

传统的离子式、吸气式、光电式等烟雾检测器在大空间中检测烟雾时,会受到发射信号与接收信号之间的距离、平面角度、精确对准等限制,无法对整个空间的烟雾状况进行描述.新的方法通过监测区域的摄像机拍摄的视频图像序列,进行小波变换,分析图像帧在时域和空域的频率特性,来确定被监测区域是否有火灾烟雾的发生.实验证明该方法不受空间高度、热障、易爆、有毒等环境的限制,并且有灵敏度高、抗干扰力强、适用范围广等特点.