可进化的入侵检测系统的模糊分类器研究

由于计算机网络中的正常行为和异常行为难以很好界定,所以许多入侵检测系统经常产生误报警。使用模糊逻辑推理方法,入侵检测系统的误报率则会明显降低,可以在入侵检测系统中,使用一套模糊规则和作用在该集合上的模糊推理算法,来判断是否发生了入侵事件。这种方法面临的主要问题是要有一个针对入侵检测的好的模糊算法。该文提出了一种使用遗传算法产生模糊分类器,以检测误用和入侵事件。主要思想是生成两个进化规则子集合,一个用于描述正常行为,一个用于描述异常行为。其中,正常行为规则进化信息来自正常使用时的操作行为,异常行为规则进化信息来自计算机网络受到入侵时的操作行为。     

进化模糊分类识别在IDS中的应用

应用进化编程自动产生若干条模糊规则以检测各种攻击。在计算机网络中,难于明确划分各种进攻的界限,因此在入侵检测系统中高误警率一直是一个主要的问题,然而利用模糊逻辑,能够有效降低误警率。同时规则的自动产生,也提高了系统的灵活性,降低了对本地网络的依赖性。论文最后给出了测试结果。     

一种进化模糊逻辑控制器的新方法

结合进化学习分类器的密歇根和匹兹堡方法的优点,首次将对单条控制规则的评价引入了模糊逻辑控制器（ＦＬＣ）的进化过程中,解决了匹兹堡类型的学习分类器系统“强化信息的带宽窄”的问题,实现了ＦＬＣ在控制器级和规则级的同时进化,控制器的控制规则数目也可以自由变化,实验结果表明新方法有较高的效率,优化的模糊控制器的结构简单,性能良好。     

模糊自适应遗传算法的原理和发展

模糊自适应遗传算法是将模糊控制器应用于遗传算法性能和参数控制的新型进化算法。该文论述了模糊自适应遗传算法的定义和基本原理,并根据规则基不同的产生方式对其进行了系统分类,最后提出了模糊自适应遗传算法性能改进和应用研究的发展方向。     

免疫算法在模糊检测器生成中的应用

目前入侵检测中传统否定选择算法忽略了正常和异常模式之间的模糊界限而造成了检测效率低下,以及生成的检测器数量冗繁,用在非我模式识别时计算复杂度相当高.针对这些缺陷,重点研究了在入侵检测系统中定义模糊检测规则的重要性,并提出利用免疫算法的优化搜索性能来进化模糊检测器的方法.实验结果表明,该方法生成的检测器能够允许更简洁的自我和非我的表示方式,降低了检测规则的脆弱性,检测效果较好.     

基于遗传优化与模糊规则挖掘的异常入侵检测

提出一种基于智能体进化计算框架与遗传模糊规则挖掘的异常入侵检测方法.通过应用模糊集分布策略、解释性的控制策略和模糊规则生成策略,实现了Agent之间的模糊集信息交换,从而有效地从网络数据中抽取正确的、可解释的模糊IF-THEN分类规则,优化了模糊系统的可解释性,并提高了系统的紧凑性.采用KDD-Cup99数据集进行测试,并与现有方法进行了比较,结果表明该方法对R2L的攻击检测性能稍弱,对DoS、Probe和U2R的攻击均具有较高的分类精度与较低的误报率.     

采用改进的进化策略优化模糊Petri网参数

模糊产生式规则的各项参数对模糊Petri网（FPN）的建立具有非常重要的意义,寻找一种可以得到合适的FPN参数的方法一直是Petri网研究领域的热点与难点。已有的寻优方法得到的参数还不太令人满意。对传统进化策略做了改进,并采用改进后的进化策略,研究了一种FPN参数优化的新方法。仿真实验的结果表明,改进后的进化策略能提高FPN的参数精度,从而增强了FPN对知识的分析、推理能力。     

基于三相连接的进化模糊神经网络及应用

介绍了一种新型的进化模糊神经网络,规则节点层融入了三相电路的连接方式,用于在线的监督学习或者无人监督学习。使用进化聚类方法,模糊规则在系统执行过程中进行创建和更新,并且采用遗传算法即时优化进化聚类的结果,通过T-S模型模糊推理系统计算输出。     

基于模糊规则集的入侵检测模型

本文提出一种基于模糊规则集的入侵检测模型FR-IDM (Fuzzy Rule-based Intrusion Detection Model),该模型采用模糊规则的表示形式来描述入侵检测知识,在此基础上建立基于模糊规则集的入侵检测模型,然后根据入侵检测信息符合前提的真度和模糊产生式的置信度,计算出该结论的可信度,根据一个激活阀值来决定是否激活该产生式。     

合作式协同进化用于模糊系统的自动生成

进化计算已经被成功地用于模糊系统自动生成.但是当输入变量增加时,一个个体对应整个模糊系统的编码方式往往会因编码太长而降低进化的效率.但每个个体代表一条规则又会给适应度评价带来困难.本文提出了一种把合作式协同进化算法用于模糊系统自动生成的新方法.每个个体代表一条或几条规则组成的子模糊系统,把所有个体分为一些子种群,这些子种群进行合作式协同进化,引入一个自适应机制动态调整种群个数,最后从每个子种群中选出最佳个体构成完整的模糊系统.实验结果显示该算法提高了进化效率.最后对个体定义等相关问题进行了讨论.     

基于小生境遗传算法的连续属性关联规则挖掘

对连续属性数据进行关联规则提取是一个重要的课题,构造了一种新的遗传算法模型,在结构上采用三段式染色体,将连续属性离散化、属性约简和关联规则提取集成在一起,并将小生境引入到遗传算法中避免“早熟”现象。实验表明了该算法是有效的。     

Extraction of Fuzzy Knowledge Bases from Experimental Data by Genetic Algorithms

This paper deals with the problem of determination of linguistic "IF-THEN" rules from available experimental data, which is inverse to the problem of identification of nonlinear dependences by fuzzy knowledge bases. A method of genetic algorithms is proposed. The method is based on the operations of crossover, mutation, and selection of initial variants of solutions or so-called chromosomes, from which the most optimal solutions are subsequently chosen. The method is illustrated by a computer experiment consisting of the determination of knowledge on a nonlinear object with two input variables and one output variable.     

FINDING SIMPLIFIED FUZZY IF-THEN RULES FOR FUNCTION APPROXIMATION PROBLEMS USING A FUZZY DATA MINING APPROACH

ABSTRACT

A fuzzy if-then rule whose consequent part is a real number is referred to as a simplified fuzzy rule. Since no defuzzification is required for this rule type, it has been widely used in function approximation problems. Furthermore, data mining can be used to discover useful information by exploring and analyzing data. Therefore, this paper proposes a fuzzy data mining approach to discover simplified fuzzy if-then rules from numerical data in order to approximate an unknown mapping from input to output. Since several pre-specified parameters for deriving fuzzy rules are not easily specified, they are automatically determined by the genetic algorithm with binary chromosomes. To evaluate performance of the proposed method, computer simulations are performed on various numerical data sets, showing that the fitting ability and the generalization ability of the proposed method are comparable to the known fuzzy rule-based methods.     

Fuzzy system parameters discovery by bacterial evolutionaryalgorithm

This paper presents a new method for discovering the parameters of a fuzzy system; namely, the combination of input variables of the rules, the parameters of the membership functions of the variables, and a set of relevant rules from numerical data using the newly proposed bacterial evolutionary algorithm (BEA). Nawa et al. (1997) proposed the pseudobacterial genetic algorithm (PBGA) that incorporates a modified mutation operator called bacterial mutation, based on a biological phenomenon of microbial evolution. The BEA has the same features of the PBGA, but introduces a new operation, called gene transfer operation, equally inspired by a microbial evolution phenomenon. While the bacterial mutation performs local optimization within the limits of a single chromosome, the gene transfer operation allows the chromosomes to directly transfer information to the other counterparts in the population. The gene transfer is inspired by the phenomenon of transfer of strands of genes in a population of bacteria. By means of this mechanism, one bacterium can rapidly spread its genetic information to other cells. Numerical experiments were performed to show the effectiveness of the BEA. The obtained results show the benefits that can be obtained with this method     

An automatic human chromosome metaspread image selection technique

The human chromosome metaspread images are used to generate the karyogram that is used for the diagnosis of the genetic defects. The genetic defects occur due to variation in either the structure of the chromosomes or the number of chromosomes present in the cell. The human chromosome metaspread image selection process is very critical in the karyogram generation task. It is very tedious and time-consuming process and is generally done manually by an expert cytogeneticist. The manual selection results may be biased, and it is possible that the whole search space is not explored to find the best metaspread image. The mood of the cytogeneticist will also greatly affect the selection results. So there is a strong need to automate the process of human chromosome metaspread image selection process. The proposed approach ranks the metaspread images based upon the quality score that is calculated using the count of the chromosomes of various orientations present in the metaspread image. The ranking has been done based upon ordinal ranking process, wherein a unique rank is assigned to each image based upon a set of rules. The rule base aids in the tiebreaking process in case the same quality score is derived for more than one metaspread image. The decision-making process of the expert cytogeneticist has been emulated by using a set of if–then rules. The proposed technique helps to select the best metaspread image, by exploring the complete set of images that can be used for the karyogram generation.     

A Genetic Approach for Simultaneous Design of Membership Functions and Fuzzy Control Rules

Based on the genetic algorithm (GA), an approach is proposed for simultaneous design of membership functions and fuzzy control rules since these two components are interdependent in designing a fuzzy logic controller (FLC). With triangular membership functions, the left and right widths of these functions, the locations of their peaks, and the fuzzy control rules corresponding to every possible combination of input linguistic variables are chosen as parameters to be optimized. By using a proportional scaling method, these parameters are then transformed into real-coded chromosomes, over which the offspring are generated by rank-based reproduction, convex crossover, and nonuniform mutation. Meanwhile, the concept of enlarged sampling space is used to expedite the convergence of the evolutionary process. To show the feasibility and validity of the proposed method, a cart-centering example will be given. The simulation results will show that the designed FLC can drive the cart system from any given initial state to the desired final state even when the cart mass varies within a wide range.     

A novel approach to design classifiers using genetic programming

We propose a new approach for designing classifiers for a c-class (c/spl ges/2) problem using genetic programming (GP). The proposed approach takes an integrated view of all classes when the GP evolves. A multitree representation of chromosomes is used. In this context, we propose a modified crossover operation and a new mutation operation that reduces the destructive nature of conventional genetic operations. We use a new concept of unfitness of a tree to select trees for genetic operations. This gives more opportunity to unfit trees to become fit. A new concept of OR-ing chromosomes in the terminal population is introduced, which enables us to get a classifier with better performance. Finally, a weight-based scheme and some heuristic rules characterizing typical ambiguous situations are used for conflict resolution. The classifier is capable of saying "don't know" when faced with unfamiliar examples. The effectiveness of our scheme is demonstrated on several real data sets.     

Genetic algorithms for video segmentation

The current paper presents a new genetic algorithm (GA)-based method for video segmentation. The proposed method is specifically designed to enhance the computational efficiency and quality of the segmentation results compared to standard GAs. The segmentation is performed by chromosomes that independently evolve using distributed genetic algorithms (DGAs). However, unlike conventional DGAs, the chromosomes are initiated using the segmentation results of the previous frame, instead of random values. Thereafter, only unstable chromosomes corresponding to moving object parts are evolved by crossover and mutation. As such, these mechanisms allow for effective solution space exploration and exploitation, thereby improving the performance of the proposed method in terms of speed and segmentation quality. These advantages were confirmed based on experiments where the proposed method was successfully applied to both synthetic and natural video sequences.     

融合GA和关联规则的数据挖掘方法改进研究

本文提出一种融合改进遗传算法和关联规则的数据挖掘方法。首先将遗传算法交叉算子和变异算子进行自适应改进,使其在迭代过程中能够根据函数适应度值自适应调节。然后将改进后的自适应遗传算法融入到关联规则中,充分利用遗传算法良好的全局搜索能力,提高处理海量数据关联规则的挖掘效率。为了避免无用规则,减少不相关性的存在,在此基础上融入亲密度以提高关联规则的可靠性。在Hadoop大数据平台上通过分析交通数据验证优化后的算法,与传统方法相比,该方法提高了算法的收敛速度和鲁棒性。     

Emergence of self‐learning fuzzy systems by a new virus DNA–based evolutionary algorithm

In this article, we propose a new approach to the virus DNA–based evolutionary algorithm (VDNA‐EA) to implement self‐learning of a class of Takagi‐Sugeno (T‐S) fuzzy controllers. The fuzzy controllers use T‐S fuzzy rules with linear consequent, the generalized input fuzzy sets, Zadeh fuzzy logic and operators, and the generalized defuzzifier. The fuzzy controllers are proved to be nonlinear proportional‐integral (PI) controllers with variable gains. The fuzzy rules are discovered automatically and the design parameters in the input fuzzy sets and the linear rule consequent are optimized simultaneously by the VDNA‐EA. The VDNA‐EA uses the VDNA encoding method that stemmed from the structure of the VDNA to encode the design parameters of the fuzzy controllers. We use the frameshift decoding method of the VDNA to decode the DNA chromosome into the design parameters of the fuzzy controllers. In addition, the gene transfer operation and bacterial mutation operation inspired by a microbial evolution phenomenon are introduced into the VDNA‐EA. Moreover, frameshift mutation operations based on the DNA genetic operations are used in the VDNA‐EA to add and delete adaptively fuzzy rules. Our encoding method can significantly shorten the code length of the DNA chromosomes and improve the encoding efficiency. The length of the chromosome is variable and it is easy to insert and delete parts of the chromosome. It is suitable for complex knowledge representation and is easy for the genetic operations at gene level to be introduced into the VDNA‐EA. We show how to implement the new method to self‐learn a T‐S fuzzy controller in the control of a nonlinear system. The fuzzy controller can be constructed automatically by the VDNA‐EA. Computer simulation results indicate that the new method is effective and the designed fuzzy controller is satisfactory. © 2003 Wiley Periodicals, Inc.