我国政府内外网安全介入平台的设计与研究

自2008年5月我国政府出台《中华人民共和国政府信息公开条例》文件以来,政府内网服务的安全面临着多重威胁和挑战,面对这一问题,文章拟建了一套构建在政府内外网之间的接入平台,其中除了常用的PKI、PMI技术,还应用了分布式数据库的处理模式,从而有效地提高了内网服务的安全性。     

SBS改性沥青同步碎石封层在桃巴高速公路中的应用

同步碎石封层在我国的使用范围很广,如湖北、四川、陕西、河北等地均有不同范围使用。SBS改性沥青同步碎石封层是其中一种,必须经过妥善处置才能保障施工质量,现就四川桃巴高速公路简单介绍SBS改性沥青同步碎石封层施工技术。     

Sliding mode control for synchronization of chaotic systems with structure or parameters mismatching

INTRODUCTION Synchronization of chaotic systems and its ap-plication to secure communication has recently re-ceived much attention. Several chaos synchronization schemes have been successfully established (Liao and Huang, 1999; Jiang, 2002; Zhao et al., 2004). How-ever, to our best knowledge, most of the chaos syn-chronization strategies have been studied in similar oscillators. In fact, from the perspective of hardware implementation, the resistance and capacitance of the resistors and…     

读者-写者问题的写者优先算法

分析了操作系统中读者-写者这个经典进程同步问题，对读者优先的算法加以改进，探讨了用信号量实现的写者优先的算法．     

基于Java的多线程实现技术

多线程是现代操作系统中出现的概念.阐述了多线程的概念以及对线程的状态、创建和控制方法,对避免死锁的方法作了深入的探讨.     

使用P、V操作解决经典进程同步问题

简要介绍P、V操作．通过对两个经典同步问题的描述，说明如何使用P、V操作解决实际问题。重点简述了使用信号量机制解决同步问题时容易产生死锁的原因以及解决死锁的方法．     

二次开发实验探索与实践

简要介绍了一个通信网络工程实验系统,提出了对该系统进行完善增设基于FPGA及DSP的二次开发实验的思路与方法。详细介绍了一个二次开发实验例子——帧成形器与帧同步器的设计与实现,二次开发实验对增强实验教学的创新实践性与工程应用性,提高学生设计开发水平及自主创新能力等具有重要意义。     

AFC时钟同步的实现与差错控制

介绍了武汉轨道交通AFC(Automatic Fare Collection)系统的基本构成和实现,在此基础上阐述了AFC系统与通信GPS时钟同步实现的原理,并对时钟同步差错控制的实现方法进行了探讨。     

基于自适应控制的非线性系统的滞后同步

Active control is an effective method for synchronizing two identical chaotic systems. However, this method works only for a certain class of chaotic systems with known parameters. An improvement method was proposed in order to overcome this limitation in this paper. A classical example was used to demonstrate the method. Finally, numerical examples were given to validate the efficiency of the method.     

Robust Joint Timing and Frequency Synchronization Algorithm for IEEE802.16e OFDM System

Based on the structures of the short preamble and long preamble,which are defined for synchronization in IEEE802.16e specification,the robust synchronization algorithm for IEEE802.16e OFDM system is proposed.The correlations among the sample sequences in the preamble are investigated,especially the correlation between the first sample sequence and the last sample sequence in the long preamble.The conventional joint timing and frequency synchronization algorithm is reviewed based on the short preamble referring to the algorithm proposed by Schmidl,then a robust joint timing and frequency synchronization algorithm is proposed based on the long preamble.The simulations in the multi-path and frequency selective fading channel show that the proposed algorithm has improved the performances of timing metric plateau,timing offset and synchronization acquisition time even when signal-to-noise ratio is less than-5 dB.