Nonlinear Dynamic Analysis of MPEG-4 Video Traffic

The main research motive is to analysis and to veiny the inherent nonlinear character of MPEG-4 video. The power spectral density estimation of the video trafiic describes its 1/f^β and periodic characteristics.The priraeipal compohems analysis of the reconstructed space dimension shows only several principal components can be the representation of all dimensions. The correlation dimension analysis proves its fractal characteristic. To accurately compute the largest Lyapunov exponent, the video traffic is divided into many parts.So the largest Lyapunov exponent spectrum is separately calculated using the small data sets method. The largest Lyapunov exponent spectrum shows there exists abundant nonlinear chaos in MPEG-4 video traffic. The conclusion can be made that MPEG-4 video traffic have complex nonlinear be havior and can be characterized by its power spectral density,principal components, correlation dimension and the largest Lyapunov exponent besides its common statistics.     

基于Ptolemy II嵌入式防火墙系统级设计与仿真研究

传统的防火墙难以抵御网络内部用户的攻击,而分布式防火墙又过分依赖于主机的操作系统,嵌入式防火墙研究已成为当前防火墙研究主流。本文提出了一种嵌入式防火墙的体系结构,介绍了嵌入式系统级建模仿真平台Ptolemy II,在该仿真平台上进行了嵌入式防火墙的建模,并对系统模型中的RTOS实时调度和包过滤算法等主要部分进行了仿真和分析。     

“后花园”战略背景下江西省入境游客的空间聚集性分析

系统收集了2000—2010年江西省11个地市的入境旅游客源数据,对入境游客的空间聚集性变化特征进行定量分析,结果显示近年来江西省入境游客的空间聚集性在下降,而空间均衡度在逐渐提高,反映出江西旅游产业开始向空间纵向发展;江西省入境客源以港澳同胞为主,但外国游客增长速度很快,其空间集聚性也呈下降趋势,表明江西入境客源逐渐稳定,有利于旅游业的发展.