Control DHT maintenance costs with session heterogeneity

The maintaining overheads of Distributed Hash Table (DHT) topology have recently received considerable attention.This paper presents a novel SHT (Session Heterogeneity Topology) model, in which DHT is reconstructed with session heterogeneity. SHT clusters nodes by means of session heterogeneity among nodes and selects the stable nodes as the participants of DHT. With an evolving process, this model gradually makes DHT stable and reliable. Therefore the high maintaining overheads for DHT are effectively controlled. Simulation with real traces of session distribution showed that the maintaining overheads are reduced dramatically and that the data availability is greatly improved.     

基于ADO.NET的海洋经济生物MIS系统

本文阐述了海洋经济生物管理多媒体信息系统的需求分析、软件结构、网络结构等.系统在研发过程中采用了最新的.NET技术,构建了一个多层、安全、可伸缩、高效的分布式应用系统.着重分析和研究了Web页面连接数据库的ADO.NET和多媒体数据处理等关键技术.系统采用了C/S和B/S相结合的体系结构,增强了系统的安全性和灵活性,为数字化海洋提供了可借鉴的解决方案.     

Distributed media cooperation for enhanced video communication

INTRODUCTION According to yearly statistics the demand for multimedia traffic over computer networks is con- stantly on the increase (Nielsen//NetRatings, http:// www.nielsen-netratings.com/). Therefore, it is inevi- table that situations where different media streams will need to share communication resources will be- come commonplace. In such cases, it would be of interest to optimize the overall performance of the network. In other words, resources should be allo- cated across the com…     

基于粗糙集的分布式信息检索

在分布式数据库技术和模糊集理论的基础上,应用作为数据挖掘的新方法的 Rough集理论,针对分布式数据库的复杂查询处理问题,构建一种基于 Rough 集的分布式数据库系统,设计出Rough集上的查询算法,降低了信息查询的时间复杂性,提高了信息查准率,兼顾了查全率,为信息查询和科技查询提供决策支持。     

CSCL环境中的社会交互

现在有很多关于计算机支持下协作学习(CSCL)异步环境中分布式学习团体(DLGs)的实证研究。研究表明当前的CSCL环境并不能完全满足人们对其支持交互的团体学习、知识共享、知识的社会建构及能力的培养的需要。在CSCL环境中,主要有两个因素阻碍我们取得预期的社会交互的成果:一是将社会交互看作是自然而然发生的,二是忽视与学习任务本身无关的社会心理交互。当前解决这个问题的办法主要是依靠教育者和教师鼓励协作学习,为了让教师从这样的负担中解脱出来,我们必须改进CSCL环境,激发和支持学习者的社会交互。     

Graduate Business Students Performance with Synchronous and Asynchronous Interaction e-Learning Methods

The effects of synchronous and asynchronous lectures and interaction formats were examined with graduate business students in on‐campus and off‐campus MBA programs. The dependent variables were scores on exams questions and learning styles and cognitive styles were used as covariates. The results indicated significant differences for discussion and lecture format and for on‐campus and off‐campus students. The results were discussed relative to learning in electronic environments.     

硫化过程的计算机控制与管理系统

本文利用可编程程序控制器PLC和IPC—610286工控微机组成一个二级集散控制系统,它成功地完成了橡胶厂内胎硫化机的生产和管理.下位机可以对 96台硫化机每一个时间进程进行严格的自动控制,以保证生产质量.上位机可方便显示和打印出班、日、月、年报表,为工厂实际生产,质量管理,计划调度,提供了有效工具,本系统已在工厂搬运,效果良好,并通过茂名市技术鉴定,获得了93年度的科技进步奖,值得推广应用.     

基于组件的分布式管理信息系统

从信息系统设计的角度描述了多层分布系统结构与优势 ,提供了基于组件分布式管理信息系统原理和技术实施方案及其和其他技术方案的比较 ,展示了基于组件分布式管理信息系统良好的应用前景     

分布式实时操作系统中的综合化系统资源管理机制与策略

本文研究了构成分布式实时控制系统的关键———分布式实时操作系统的结构及内在机制, 介绍在分布式实时操作系统中采用综合化的系统资源管理机制管理系统资源, 满足分布式实时控制应用的特殊要求.     

Systematic lossy error protection based on H.264/AVC redundant slices and flexible macroblock ordering

INTRODUCTION In typical video transmission systems, a video signal is compressed, and the resulting bit stream is transmitted over an error-prone channel. The errors may consist of symbol errors caused by fading, as observed for wireless channels, or packet erasures caused by congestion, as observed in the Internet. If a received video packet contains errors, then the portion of the video signal contained in the packet is lost and must be concealed. Error concealment schemes alone cannot …