一种面向空地一体化组网的体系架构

空间网络是空地一体化组网中地面网络延伸的重要组成部分。针对空间网络为移动星座的场景,传统的空地一体化组网模型将空间网络视为独立自治域,利用边界网关协议将空间网络与地面自治域互联起来,最大化同地面网络保持兼容。然而,传统组网模型存在边界网关面临频繁会话中断或大量路由更新等问题。通过重新审视空间网络的角色定位和边界划定问题,提出一种面向空地一体化组网的体系架构Slink。Slink的核心思想是空间网络为地面网络提供互联通道,利用星地网关隔离空地两网间的路由更新。实验仿真表明,Slink体系架构能够有效减小对空间路由器的路由存储空间需求,降低星地网络间的带宽消耗。     

Recover Fault Services via Complex Service-to-Node Mappings in Wireless Sensor Networks

With the motivation of seamlessly extending wireless sensor networks to the external environment, service-oriented architecture comes up as a promising solution. However, as sensor nodes are failure prone, this consequently renders the whole wireless sensor network to seriously faulty. When a particular node is faulty, the service on it should be migrated into those substitute sensor nodes that are in a normal status. Currently, two kinds of approaches exist to identify the substitute sensor nodes: the most common approach is to prepare redundancy nodes, though the involved tasks such as maintaining redundancy nodes, i.e., relocating the new node, lead to an extra burden on the wireless sensor networks. More recently, other approaches without using redundancy nodes are emerging, and they merely select the substitute nodes in a sensor node’s perspective i.e., migrating the service of faulty node to it’s nearest sensor node, though usually neglecting the requirements of the application level. Even a few work consider the need of the application level, they perform at packets granularity and don’t fit well at service granularity. In this paper, we aim to remove these limitations in the wireless sensor network with the service-oriented architecture. Instead of deploying redundancy nodes, the proposed mechanism replaces the faulty sensor node with consideration of the similarity on the application level, as well as on the sensor level. On the application level, we apply the Bloom Filter for its high efficiency and low space costs. While on the sensor level, we design an objective solution via the coefficient of a variation as an evaluation for choosing the substitute on the sensor level.     

依托网络教学平台 提高课堂教学效果

网络教学作为一种新的辅助教学手段,是目前教学改革主要研究的方向之一。通过对网络教学平台的功能分析,探讨了在网络教学平台上进行教学资源的建设、交流互动教学活动的开展和虚拟实验室的建设,通过应用实践证明,充分利用网络教学平台的优势,能有效地提高课堂教学质量和效率,培养学生的学习能力、实践能力和创新能力。     

计算机在高校实验室管理中的应用

计算机技术的迅速发展给人们的生活学习及工作带来了很多便利,并且计算机技术已经被广泛应用到了各个领域中。本文就计算机在高校实验室管理应用中的问题进行了分析和讨论。     

Statistically uniform intra-block refresh algorithm for very low delay video communication

This paper focuses on the mechanism underlying the overall delay of a real-time video communication system from the time of capture at the encoder to the time of display at the decoder. A detailed analysis is presented to illustrate the delay problem. We then describe a statistically uniform intra-block refresh scheme for very low delay video communication. By scattering intra-blocks uniformly into continuous frames, the overall delay is significantly decreased, and object changes in the scene could be presented to the end user instantly. For comparison, the overall delay and the peak signal-to-noise ratio (PSNR) performance are tested. The experiment results show that an average of approximately 0.1 dB PSNR gain on average is obtained relative to random intra-macroblock refresh algorithm in H.264 JM, and the end-to-end delay performance is significantly improved.     

"交换机与路由器"课程教学改革策略研究

本文依据交换机与路由器学科技术的特点及教学实践中存在的现实问题,展开了对教材建设、教学手段及教学模式的全面探讨,并制定了科学有效的实践教学改革策略,对提升交换机与路由器技术课程教学效果水平有重要的推进作用.     

内嵌GPS和GSM功能的野外测量终端模型

本文介绍所设计的一种带GPS定位和GSM通讯功能的野外测量终端模型系统。系统采用μC/OS-II嵌入式实时操作系统,以基于ARM并辅以GSM和GPS模块为硬件平台,提供给野外测量终端用户基本的通话功能和个人定位信息,为实时采集地理信息作基础。     

信息技术课堂分层教学的实践与思考

新课程背景下的教学理念是“以学生发展为本”,在以机房环境为主的信息科技学科教学过程中如何关注每一位学生的有效学习,使他们的信息素养得到充份的发展对教师提出了相当高的要求。在教学各环节实施分层教学能体现教师对每一位学生的关爱,也能切实提高教学有效性。该文从关注每一位孩子的成长角度,简述了分层教学在初中信息科技学科教学中的实施策略及相关思考。