基于UDP协议和虚拟令牌的实时网络协议

针对目前工业生产和科研领域对大量实时数据传输的迫切需要,在分析现存各种网络协议的优点和不足的基础上,融合UDP协议和令牌总线802.4标准的优点,提出了基于UDP协议和虚拟令牌的实时网络协议.对该协议如何实现"实时性"和"可靠性"的机理进行了详细的阐述,给出了该协议的帧格式及虚拟令牌的格式.最后用一个使用该协议实现的点到点传输的实例,对该协议的性能进行了初步的论证.     

IP移动环境下的SIP号码移动性研究

介绍了移动IP技术的基本原理及其不足,给出了一种利用SIP协议支持IP移动性的实现方案,并详细分 析了呼叫与通信过程中SIP支持IP移动性的实现流程,对.SIP和移动IP混合支持IP移动性作了进一步的探讨。     

基于MPLS的VPDN网络研究与实现

虚拟拨号专用网络(VPDN:Virtual Private Dialup Network)是VPN(Virtual Private Network)应用扩展.为有效地降低封装开销,在简要介绍了VPDN第2层实现的基本原理基础上,对VPDN关键技术进行了分析,比较了PPTP(Point to Point Tunneling Protocol)和L2TP(Layer 2 Tunneling Protocol)隧道协议封装形式以及IPSec的安全特点.提出了第3层基于MPLS(Multi Protocol Label Switch)实现VPDN的设计方法以及VPDN需要进一步研究的问题.该方案可降低封装开销约5.8%,为第3层VPDN研究提供了一个有益的设计思路.     

CORBA与Web服务集成技术

为了解决企业内部的遗留系统如何通过标准的Web服务技术实现互访的问题,通过对基于Web服务的典型应用集成场景的分析,参考Object Management Group(OMG)的相关规范,提出了更为全面的集成模型.其中新加入了基于Servant的SOAP-CORBA网关,对规范进行了必要的补充,并克服了其他同类系统未能解决的性能瓶颈和单点失效问题,而且本模型更易于灵活的分发部署,有利于整个系统的负载平衡.通过实验验证和分析,证明了模型的可行性,同时具有 良好的性能.     

Consensus design for continuous-time multi-agent systems with communication delay

This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication delay.Provided that the agent dynamic is unstable and the diagraph is undirected,sufficient conditions are derived to guarantee consensus.The key technique is the adoption of historical input information in the protocol.Especially,when agent＇s own historical input information is used in the protocol design,the consensus condition is constructed in terms of agent dynamic,communication delay,and the eigenratio of the network topology.Simulation result is presented to validate the effectiveness of the theoretical result.     

基于Wimax无线网络的矿井监测系统

该文介绍了一种基于Wimax无线网络的矿井监测系统,主要分析个这种监测网络的构成、基于IEEE802.16e协议的无线传感器的硬件系统设计及协议栈的设计并依据矿井所需传感器的特点对无线传感器接入Wiamx网络的流程给予简化,在和中兴通讯合作的某煤矿实验网中,完全显示出采用这种国际标准的有点,即可共用也可专用并且成本底下,可与地方电信运营商共用设备。     

基于VB的三菱FX系列PLC与PC串行通信的实现

结合FX系列可编程序控制器的特点．详细分析了PLC与PC间的通信协议．并给出了利用VB6．0实现PC与PLC串行通信的设计过程。     

Design and Implementation of a Fibre Channel Target Driver Supporting SCSI

Fibre channel storage area networks (FC-SAN) are effective solutions to address storage management problems caused by very large volumes of data. But the expense of fibre channel devices limits FC-SAN applications. The use of IP networks instead of fibre channel networks will reduce SAN cost, but will also reduce the performance. Therefore, small computer system interface (SCSI) devices were considered to replace FC disks to reduce the SAN cost. A driver for the FC network adapter and the FC target, designed and implemented to support this structure, obeys the SCSI protocol and works in target mode with 200 MB/s bandwidth. The FC target architecture and implementation were compared with the FC initiator.The SCSI command transfer process in the FC layer was described. The performance test results show that the maximum I/O throughput reachs 167 MB/s for read requests and 196 MB/s for write requests (FC bandwidth is 200 MB/s), verifying that the FC target is very efficient. The modularization, efficiency, and low cost of the FC target will enable SAN and fibre channel to be more widely used in applications.     

A Dynamic Object Behavior Model and Implementation Based on Computational Reflection

A dynamic object behavior model based on computational reflection is proposed. This model consists of function level and meta level, the meta objects in meta level manage the base objects and behaviors in function level, including dynamic binding and unbinding of base ohject and behavior. We implement this model with RoleJava Language. which is our self linguistic extension of the Java Language. Meta Objects are generated automatically at compile-time, this makes the reflecton mechanism transparent to programmers. Finallyan example applying this model to a banking system is presented.     

快速生成树协议端口角色选择算法的研究

介绍了快速生成树协议优于生成树协议之所在，提出了一个数学模型，在此模型的基础上对端口角色选择算法进行了全面的阐述，并且给出了一个计算实例，详细描述了其端口角色的选择过程．