基于虚拟机的运行时入侵检测技术研究

入侵检测技术通常分为误用检测和异常检测两类,误用检测根据攻击模式库检测已知的攻击行为,但却难以防范未知的攻击行为;异常检测技术虽然可以预测偏离正常值阈区间的潜在攻击行为,但却存在较高的误报现象。在虚拟机监视器中对虚拟机操作系统的运行行为进行带外监控,避免了操作系统内监控模块被病毒感染的难题;通过监视虚拟机的运行时行为,对之作组合序列的合法性分析,扩展了误用检测防范长时间段攻击行为的能力,识别通过合法系统调用进行的恶意攻击。测试数据表明,该技术能够较好地检测出复杂组合攻击行为。     

HTTP多路超链接在WebServers中的应用

频繁的WWW访问要求有有效的WebServers组织方式,针对HTTP超链接不能进行负载平衡的缺点,提出了HTTP多路超链接,并用HTTP超链接对HTTP多路超链接进行了模拟,最后将HTTP多路超链接引入WebServers设计。     

电力调度支持系统中安全校核应用的设计与实现

为实现电网安全与经济运行,对调度计划进行闭环安全校核具有重要意义.基于SOA架构,对电网调度支持系统中的安全校核应用进行结构设计,实现安全校核应用与其他应用的数据共享及服务调用,通过重构安全校核流程,整合计划数据与实时数据,实现安全校核的闭环控制.实现过程应用并行计算技术提高了计算效率,采用JAVA 2D等技术展示安全校核计算结果,直观形象地反映出电网的安全水平.安全校核应用的实现,提升了电网安全运行的预防性控制能力.     

A research on the contact stress of roller bearing based on crowning analysis

According to elastic contact theory,contact model between roller and race is established.Compared with the Hertz results,the results are proved,based on which contact stress distribution of different crowning and initial contact length is given,then the appropriate value is derived.On the basis,inertia force and different radial force is given into consideration.Via analysis,it concludes that under balanced pure radial load condition the largest contact stress between roller and race increases along with crowning value increasing.With the same crowning value,the largest contact stress between roller and race decreases in the first and increases at the end along with initial contact length increasing.Contact stress between roller and outer race increases along with revolution speed increasing.     

Abnormal growth of austenite grain of low-carbon steel

Niobium is an important alloying element for the steel. To know further the effect of Nb in the steel, the contrast experiments on the austenite grain growth of the 0.015%Nb and free Nb steels were carried out using Gleeble 1500 thermomechanical simulator. The experimental results indicate that the austenite grain of 0.015%Nb steel is finer than that of Nb free steel at 1150–1230 °C. And when the heating temperature arrives the critical temperature 1240 °C, the austenite grain of Nb steel suddenly grows up, while the austenite grain of Nb free steel changes little. Finally, the austenite grain of Nb steel is obviously coarser than that of Nb free steel. By transmission electron microscopy (TEM) using a carbon extraction replica technique, the precipitates of Nb(C,N) were not observed in the 0.015%Nb steel. It is concluded that the grain-boundary internal adsorption of Nb atoms leads to the result.     

利用无移动运动技术实现运动图像的显示

对于运动图像的显示，本文引入了一种无移动运动技术，这项技术的核心思想是利用一对正交的定向滤波核，并通过不断改变其相位得到一系列“运动”的图像，使图像内的物体在实际位置并不发生改变的情况下，产生视觉上的运动效果，本文将其应用于一幅BMP位图图像，并取得了很好的效果。     

直线步进电动机单片微机控制与应用

提出利用单片微机作为开发平台，建立了一个测试系统来控制直线步进电机的时序脉冲，向直线电动机提供运行中节拍和方向指令，建立控制运行表格这达到直线步进电机按指定速度向指定方向运行到给定距离的目的。     

Shift and scale‐invariant correlation for pattern recognition based on the bidimensional empirical mode decomposition with noise robustness

Abstract

A novel filter is proposed to improve the noise robustness and discrimination capability for shift and scale invariant pattern recognition. This filter is a combination of mellin radial harmonic filter (RHF) and the bidimensional empirical mode decomposition. The basic principle of this method is to make use of partial reconstructions of the image by the relevant intrinsic mode functions corresponding to the most important structures of the image. A criterion is proposed to determine the proper number of intrinsic mode functions to be discarded for denoising by discussing the characteristic of the noise. The proposed filter provides a wider allowable scale change of the object. Within this range, the correlation peak intensity is relatively uniform even in the case of noise. This proposed filter has been tested experimentally to confirm the result from numerical simulations for cases with and without additive white Gaussian noise.     

Perl程序设计语言综述

Perl语言是在吸收了众多程序设计语言的长处基础之上发展起来的是一门优秀的程序设计语言,在很多领域都有所应用。论文试图对该语言作一个较为全面的介绍,并期待该语言能在我国的计算机应用领域得到广泛的应用。     

基于OpenSSL的VNC安全性研究及实现

VNC以其真正的瘦客户技术和平台独立性,在网络计算领域得到了广泛的应用,但它在网络安全性方面存在缺陷,使其难以应用于企业应用服务系统中。在分析VNC安全机制的基础上,提出了解决方案,并利用Openssl中提供的密码算法库,实现其安全解决方案。