网络蠕虫传播建模分析

概述了当前几种常用的蠕虫病毒传播模型,具体分析了随着因特网体系结构的演化,网络中NAT等设施的出现对蠕虫病毒传播带来的影响。针对传统模型在描述病毒传播过程中的一些不足,对一种解析主动蠕虫病毒传播模型进行了改进,提出了蠕虫病毒的两阶段传播模型。仿真结果与CAIDA实际测量的RedCodev2传播数据相比较表明,改进后的模型能更好地描述病毒的传播规律。     

Thermal,viscoelastic and mechanical properties' optimization of polyphenylene sulfide via optimal processing parameters using the Taguchi method

Thermal, viscoelastic and mechanical properties of polyphenylene sulfide (PPS) were optimized as a function of extrusion and injection molding parameters. For this purpose, design of experiments approach utilizing Taguchi's L₂₇ (3⁷) orthogonal arrays was used. Effect of the parameters on desired properties was determined using the analysis of variance. Differential scanning calorimeter (DSC) tests were performed for the analysis of thermal properties such as melting temperature (T_m) and melting enthalpy (ΔH_M). Dynamic mechanical analysis (DMA) tests were performed for the analysis of viscoelastic properties such as damping factor (tan?δ) and glass transition temperature (T_g). Tensile tests were performed for the analysis of mechanical properties such as tensile strength and modulus. With optimized process parameters, verification DSC, DMA and tensile tests were performed for thermal, viscoelastic and mechanical properties, respectively. The Taguchi method showed that ‘barrel temperature’ and its level of ‘340°C’ were seen to be the most effective parameter and its level; respectively. It was suggested that PPS can be reinforced for further improvement after optimized thermal, viscoelastic and mechanical properties.     

基于激光扫描的人脸软组织三维重建研究

提出了基于激光扫描技术进行人脸软组织三维重建的方法.首先采用激光扫描系统对人脸进行扫描,然后利用采集的点云数据,通过计算机辅助设计与制造(CAD/CAM)中的反求工程方法,建立面部三维曲面模型.通过重建的模型与原始点云数据进行比较分析可知,面部轮廓的反求精度可达0.30～0.02 mm.利用本文所提出的面部软组织重建方法,可以为颌面外科与面部正畸研究提供三维研究模型.     

英汉虚构位移结构分析

虚构位移表达是对静态场景的一种动态表征形式。在虚构位移结构中,位移词用来描述并不发生实际运动的静态实体,在语言表层凸显静态实体的某种物理运动。利用Langacker认知语法中的射体(trajector)、路标(landm ark)来分析虚构位移的语言结构特点,可以发现隐现在语言结构中的观察者或其视线发生了位移,其中观察者采用顺序扫描来建构语义内容。     

频相扫三坐标雷达目标中频回波模拟研究

分析了频相扫三坐标雷达的工作原理以及目标中频回波模拟的必要性,在此基础上建立了比较全面和逼真的目标中频回波模型,并给出了频相扫三坐标雷达的目标中频回波的模拟方法。仿真结果表明该方法较好地反映了频相扫三坐标雷达的目标特性,在频相扫三坐标雷达系统的性能评估中得到了很好的应用。     

Exploring environmental scanning for China's government information: A government official's perspective

This study examined strategic government-information scanning in China from the perspective of government officials by a survey. TV, government officials/party members, newspapers, and government websites were the most important sources. Information from individual sources was perceived differently in six quality aspects. Structural Equation Modeling results revealed that source importance was significantly predicted by information quality in TV and government websites but not in the other two sources.     

日语泛读授课方法初探

学生们在日文阅读及解题中容易遇到一些理解上的错误,文章针对这些问题,从授课方式和授课内容上对日语泛读这门课做了初步的探究.     

智能时间程序控制器

本文提出了一种智能时间程序控制器 ,并给出了硬件电路和软件算法     

FPS系统中场的解析法分析

本文引入运动坐标,将复杂的边界条件展为傅里叶级数,并选择适当的坐标参量,用分离变量法导出了采用图案型偏转轮的摄象管的聚焦、投射和扫描(FPS)系统空间电位分布的形式简洁的严格解。并在统一坐标系下,求出了磁场分布。本文的解克服了以往文献的解的结构复杂和计算量大的弱点,使得可用解析法求出FPS系统的特性参量和在小型计算机上实现FPS系统的最优化设计。     

数字自动印刷机PC图文采集系统的研制

提出了一种简捷的数字式自动印刷机ＰＣ图文采集方法。通过对数字式自动印刷机进行简单的改进,使其成为计算机的图文扫描输入装置,在实际使用中取得了很好的效果。本文在介绍了数字式自动印刷机工作原理的基础上,阐述了ＰＣ图文采集系统的总体方案及其硬件和软件的实现方法。