The effectiveness of using procedural scaffoldings in a paper-plus-smartphone collaborative learning context

The purpose of this study was to evaluate the effectiveness of using procedural scaffoldings in fostering students’ group discourse levels and learning outcomes in a paper-plus-smartphone collaborative learning context. All participants used built-in camera smartphones to learn new knowledge by scanning Quick Response (QR) codes, a type of two-dimensional barcode, embedded in paper-based learning materials in this study. Sixty undergraduate and graduate students enrolled at a four-year university in southern Taiwan participated in this study. Participants were randomly assigned into two different groups, using procedural scaffoldings learning and non-procedural scaffoldings learning. The learning unit about the Long Tail, an important concept used in products sales, was the learning task that participants were expected to complete. During the experiment, pretest–posttest and the completed group worksheets were used to collect data. The researchers applied content analyses, chi-square test, t-test, and ANCOVA to answer research questions. The findings indicated that participants in the experimental group using procedural scaffoldings achieved better learning outcomes than their counterparts in the control group in terms of group discourse levels, group learning, and individual learning.     

Cooperative private searching in clouds

With the increasing popularity of cloud computing, there is increased motivation to outsource data services to the cloud to save money. An important problem in such an environment is to protect user privacy while querying data from the cloud. To address this problem, researchers have proposed several techniques. However, existing techniques incur heavy computational and bandwidth related costs, which will be unacceptable to users. In this paper, we propose a cooperative private searching (COPS) protocol that provides the same privacy protections as prior protocols, but with much lower overhead. Our protocol allows multiple users to combine their queries to reduce the querying cost while protecting their privacy. Extensive evaluations have been conducted on both analytical models and on a real cloud environment to examine the effectiveness of our protocol. Our simulation results show that the proposed protocol reduces computational costs by 80% and bandwidth cost by 37%, even when only five users query data.     

从交际意图和语言交际的发展变化来看“质的准则”

讨论了格赖斯"合作原则"中"质的准则",指出"质的准则"不是一条道德准则,它具有随机性和不确定性。     

瑞利信道下多门限频谱合作感知方法研究

随着通信方式由语音转向多媒体应用,人们对高速无线传送的需求与日俱增。然而由于有限的自然频谱,现行的静态频率分配机制不能满足快速激增的高速通信设备的要求。因此,需要能够提高频谱利用效率的创新技术,认知无线电的出现解决了这种频谱拥塞的问题,本文将研究在能量探测频谱感知过程中使用多门限判决方法,在认知无线电网络中,决策中心接收多个认知无线电的观测数值,做出决定判断是否存在主用户。研究表明在瑞利信道下进行能量探测的合作频谱感知,采用多门限的判决方法能使感知效果的到提升。     

对足球教学中合作学习教学模式的研究

未来社会不仅需要竞争意识，更需要合作精神。采用文献资料法，问卷调查法，专家访谈法，对比分析法，并结合日常足球教学，对合作教学模式进行理论探讨和研究，以期解决传统教学模式对学生情感和创造性思维的束缚，并进一步探究这种模式对学生的同伴关系、学习兴趣、教学能力、分析解决问题能力、合作意识的能力的影响，旨在为现有足球教学模式的改革提供有益的理论参考。     

协同图形编辑系统设计与实现

给出了基于图形对象的协同编辑系统的操作冲突／相容关系及其基于逻辑时间钟的检测方法和一致性保证算法。在此基础上，讨论了一个实时协同图形编辑系统的设计方面有关的关键技术。实验结果表明，该方法是可行和有效的。     

A distributed motion coordination strategy for multiple nonholonomic mobile robots in cooperative hunting operations

This paper presents a distributed smooth time-varying feedback control law for coordinating motions of multiple nonholonomic mobile robots of the Hilare-type to capture/enclose a target by making troop formations. This motion coordination is a cooperative behavior for security against invaders in surveillance areas. Each robot in this control law has its own coordinate system and it senses a target/invader, other robots and obstacles, to achieve this cooperative behavior without making any collision. Each robot especially has a two-dimensional control input referred to as a “formation vector” and the formation is controllable by the vectors. The validity of this control law is supported by computer simulations.     

一个虚拟教室的协同感知技术

协同感知技术近来成为CSCW和CSCL的一个新的研究领域，它足一个先进的人机接口技术。该文介绍了一个在虚拟教室中实现的协同感知代理的框架结构以及这个协同感知代理的工作过程，在该协同感知过程中实现了对感知信息的灵活过滤，提高了协同感知的效率。     

基于SATER模型的多媒体远程教学平台的设计与实现

在简要分析了远程教学平台设计原则的基础上,提出了一种包括学生S管理员A教师T远程教学环境E和教学资源R的SATER结构模式,进一步讨论了基于Internet/Intranet的多媒体远程教学平台的组成、功能和数据库设计,兼顾了师生间协同学习和分布学习,并在中国科学技术大学校园网上试运行。     

基于C／S的CAD协同设计环境的产品数据管理技术

数据管理系统是ＣＡＤ协同设计环境核心系统之一。此文介绍了基于Ｃｌｉｅｎｔ／ＳｅｒｖｅｒｒＣＡＤ协同设计环境的数据管理关键技术，看重介绍了数据的模型结构和组织，数据库设计，版本管理，配置管理，数据安全性及一致性控制等内容。最后对系统实际应用效果进行了评价。