基于遗传优化神经网络的网络入侵特征检测

为了提高网络入侵检测正确率,提出一种遗传优化神经网络的网络入侵特征选择和检测算法。该方法先将网络状态特征和RBF神经网络参数作为遗传算法的个体,把检测正确率作为适应度函数;然后利用遗传算法的选择、交叉和变异等操作对网络状态特征和RBF神经网络参数进行优化,最后利用KDD 1999数据集对算法性能进行测试。测试结果表明：遗传优化神经网络能够快速获得最优网络状态特征和分类器参数,同时提高了网络入侵检测正确率。     

GARBF在网络入侵检测中的应用研究

研究网络安全问题,提高入侵检测效率,针对网络入侵检测传统采用RBF神经网络方法在网络入侵中由于初始权值设定不当导致检测入侵耗时长、正确检测率低,误报和漏报率记的难题,为了解决上述问题,提出了一种GARBF神经网络入侵检测模型.GARBF神经网络模型在网络入侵检测过程中,采用遗传算法对RBF神经网络初始权值进行优化,然后将网络入侵数据输入优化的RBF神经网络中进行学习和检测.结果表明,相比较传统网络入侵检测模型,网络入侵检测误报率、耗时都较低,证明提高网络入侵检测的正确性和效率.     

基于混沌PSO算法优化RBF网络入侵检测模型

针对网络安全中异常入侵检测,给出了一种构建最优神经网络入侵模型的方法。采用混沌扰动改进粒子群优化算法,优化径向基函数RBF神经网络入侵模型。把网络特征子集和RBF神经网络参数编码成一个粒子,通过粒子间的信息交流与协作快速找到全局最优粒子极值。在KDD Cup 99数据集进行仿真实验,实验数据表明,建立了一种检测率高、速度快的网络入侵检测模型。     

PSO算法和神经网络的入侵检测系统设计

针对入侵检测系统检测率低,整体性能不好的问题,在探讨入侵检测技术和人工神经网络理论的基础上,提出了一种基于PSO算法优化的径向基函数神经网络的入侵检测系统,采用具有全局寻优的功能PSO算法,该算法能够改进传统的RBF神经网络学习策略,弥补RBF神经网络参数设置的不足,采用了来自KDD CUP99的权威数据来进行网络学习和测试,在此基础之上,进行了入侵检测系统的设计与实现,实验结果表明,基于PSO和RBF神经网络的人侵检测系统有效地提高了入侵检测的效率.     

集成模型在网络入侵检测中的仿真研究

研究保证网络安全问题,针对网络入侵具有多样性和复杂性,信息冗余十分严重,传统检测方法不能很好消除冗余信息,导致检测时间长和检测正确率低的难题.为了提高检测准确性,将主成分分析和RBF神经网络相结合起来,组成一个集成的网络入侵检测模型.模型首先通过主成分析分析法对网络原始数据进行预处理,降低特征维数、消除冗余信息,将处理后特征作为神经网络的输入,网络入侵类型作为神经网络的输出,建立RBF神经网络入侵检测模型对网络数据进行检测.在Matlab平台上,采用权威网络入侵数据DARPA数据集对集成模型进行预试,仿真结果表明,集成模型的网络入侵检测正确率高于传统入侵检测模型,加快了网络入侵检测速度,为网络入侵提供了一种实时检测方法.     

基于改进RBF神经网络的入侵检测研究

近年来,神经网络技术在入侵检测中得到了广泛应用,其中最具代表的是BP神经网络,但其本身所具有的局部极小性质限制了检测性能的提高。RBF神经网络在一定程度上克服了BP神经网络存在的问题,但如何确定一个合适的RBF网络隐层神经元中心个数又是保证其应用效果的关键之一。因此,将基于熵的模糊聚类和RBF神经网络相结合,提出了基于EFC的改进RBF神经网络算法,并将该方法应用于入侵检测研究。实验表明,该算法可以获得满意的性能。     

基于集成RBF神经网络的入侵检测研究

本文提出了一种基于集成RBF神经网络的入侵检测研究,通过对初始化聚类子算法的改进,从而提高了RBF神经网络的训练速度,采用集成理论对RBF神经网络的集成以提高检测率。实验结果表明,集成神经网络比RBF神经网络的检测率提高了1%,且降低了误报率和漏报率。     

基于Boosting RBF神经网络的入侵检测

提出一种新颖的基于boosting RBF神经网络的入侵检测方法。将模糊聚类和神经网络技术相结合,提出基于改进的FCM算法和OLS算法相结合的FORBF算法,为了提高RBF神经网络的泛化能力,采用Boosting方法,进行网络集成。以“KDD Cup 1999 Data”网络连接数据集训练神经网络并仿真实验,得到了较高的检测率和较低的误警率。     

基于PSO-RBF无线传感器网络入侵检测技术研究

针对无线传感器网络自身特性,提出了基于粒子群优化(PSO)径向基函数(RBF)神经网络的轻量级入侵检测方案,该方案结合PSO算法与RBF神经网络分别在全局搜索和局部搜索的优势,使用PSO优化RBF的中心、宽度及权值.仿真实验表明:基于PSO-RBF的入侵检测算法可以有效、可靠地运用于无线传感器入侵检测系统中.     

量子遗传算法优化神经网络的MIMO-OFDM检测研究

信号的最优检测在常规条件下是一NP难解问题,针对RBF（径向基函数）神经网络算法易陷入局部极值和简单遗传算法收敛速度慢的问题,提出一种新型智能算法并将其用于MIMO-OFDM系统信号检测中：该算法将量子计算、遗传算法与神经网络相结合,用量子遗传算法（QGA）优化神经网络初始值。由于QGA给RBF网络提供了较好的初始值,故能够使RBF网络快速收敛到最优解,避免了由初始值的随机选取而带来的检测误码。实验结果表明,该算法能够有效地提高系统的信号检测性能,降低误码率。     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.