Adaptive Modeling for Security Infrastructure Fault Response

Based on the analysis of inherent limitations in existing security response decision-making systems,a dynamic adaptive model of fault response is presented.Several security fault levels were founded,which comprise the basic level,equipment level and mechanism level.Fault damage cost is calculated using the analytic hierarchy process.Meanwhile,the model evaluates the impact of different responses upon fault repair and normal operation.Response operation cost and response negative cost are introduced through quantitative calculation.This model adopts a comprehensive response decision of security fault in three principles-the maximum and minimum principle,timeliness principle,acquiescence principle,which assure optimal response countermeasure is selected for different situations.Experimental results show that the proposed model has good self-adaptation ability,timeliness and cost-sensitiveness.     

基于直觉模糊——神经网络的色情图像识别算法

网络中色情图像的传播严重影响了网络信息内容的安全性。为提高色情图像识别的准确度,提出了一种直觉模糊理论和FP（Forward Propagation）神经网络相结合的色情图像识别算法。算法以颜色直方图为底层特征,根据色情图像颜色分布情况,由模糊理论和直觉模糊理论共同构建图像特征矩阵;采用FP网络实现色情图像特征训练过程,其中特征矩阵的权重通过反向传播神经网络训练得到,以加权距离建立球形邻域半径;最后通过球形邻域覆盖情况识别色情图像。实验结果表明,该算法能够在不影响识别速率的前提下,有效的提高识别准确度。     

Image Retrieval Approach Based on Intuitive Fuzzy Set Combined with Genetic Algorithm

Aiming at shortcomings of traditional image retrieval systems,a new image retrieval approach based on color features of image combining intuitive fuzzy theory with genetic algorithm is proposed.Each image is segmented into a constant number of sub-images in vertical direction.Color features are extracted from every sub-image to get chromosome coding.It is considered that fuzzy membership and intuitive fuzzy hesitancy degree of every pixel's color in image are associated to all the color histogram bins.Certain feature,fuzzy feature and intuitive fuzzy feature of colors in an image,are used together to describe the content of image.Efficient combinations of sub-image are selected according to operation of selecting,crossing and variation.Retrieval resuits are obtained from image matching based on these color feature combinations of sub-images.Tests show that this approach can improve the accuracy of image retrieval in the case of not decreasing the speed of image retrieval.Its mean precision is above 80%.     

模糊Petri网知识表示方法在入侵检测中的应用

根据网络攻击具有并发性,攻击特征的提取具有不确定性等特点,给出了采用模糊Pelri网实现攻击知识的表达和入侵检测的推理模型。该模型解决了误用入侵检测系统中现有知识表示方法不能并行推理的问题,以及传统的基于Pelri网可达图搜索求解导致模型描述复杂、推理缺少智能的问题。最后通过入侵实例验证了该模型的正确性和有效性。     

基于概率内存分配的内存安全研究

Some unsafe languages, like C and C+ + , let programmers maximize performance but are vulnerable to memory errors which can lead to program crashes and unpredictable behavior. Aiming to solve the problem, traditional memory allocating strategy is improved and a new probabilistic memory allocation technology is presented. By combining random memory allocating algorithm and virtual memory, memory errors are avoided in all probability during software executing. By replacing default memory allocator to manage allocation of heap memory, buffer overflows and dangling pointers are prevented. Experiments show it is better than Die-hard of the following aspects: memory errors prevention, performance in memory allocation set and ability of controlling working set. So probabilistic memory allocation is a valid memory errors prevention technology and it can tolerate memory errors and provide probabilistic memory safety effectively.     

探地雷达目标检测中的离散余弦变换方法

提出了一种以一维离散余弦变换分量作为特征量的探地雷达目标粗略检测方法.首先对探地雷达A-scan信号进行离散余弦变换,而后根据目标与背景处A-scan离散余弦变换最小分量差异较大的特点,引入离散余弦变换最小分量平方作为检测特征量,最后选取特定的阈值进行目标位置的判断,实现目标的粗略检测.实验结果表明,离散余弦变换最小分量作为检测特征量检测定位比较准确,虽然计算时间比能量法长,但精度比能量法高,可以用于目标的粗略检测.     

多传感器信息融合技术最新发展及其研究展望

在分析多传感器信息融合技术发展现状的基础上，对多传感器信息融合技术进一步的研究趋势进行了探讨。     

WindowsNT/2000典型漏洞特征分析及知识表达方法

知识表达是专家系统的一个重要环节.文中叙述了在构建漏洞知识库过程中,利用漏洞进行攻击的特征提取以及特征知识表达的方法.     

模糊时间序列的最优预测方法

以模糊时间序列的 Ｆ Ａ Ｒ（ｐ ）为基础，建立了模糊时间序列的最优预测原则、计算原理及计算方法，探讨了实时预测途径，并通过仿真验证了所建立的最优预测方法的有效性。