基于人工免疫网络和模糊C-均值聚类的入侵检测方法

针对入侵检测方法中模糊C-均值(FCM)聚类算法对初始值敏感和要求输入聚类数目的缺点,把人工免疫网络算法用于FCM聚类算法,提出了一种基于人工免疫网络和模糊C-均值的入侵检测方法.通过KDD_CUP1999数据集仿真试验,与FCM算法相比,该算法提高了检测率,降低了误警率.实验结果表明,该方法能够有效地检测网络中的入侵行为.     

基于聚类与决策树的综合入侵检测算法研究

入侵检测是一种通过实时监测目标系统来发现入侵攻击行为的安全技术,传统的入侵检测系统在有效性、适应性和可扩展性方面都存在着不足。为了使模糊聚类算法获得的聚类结果为全局最优解,改进了传统的模糊C-均值算法,并且在每个聚类的数据集上建立一棵属于该聚类的C4.5决策树,构造了一种新的综合检测算法来确定是否存在入侵。通过实验结果分析,该检测算法降低了误报率,提高了入侵检测的检测性能以及可靠性。     

入侵检测中基于遗传禁忌搜索的模糊聚类的应用

传统的模糊C均值聚类(FCM)算法须事先指出聚类数,该算法对孤立点和初始聚类敏感、易陷入局部最优,这些因素都将影响最终聚类结果的质量.针对这些缺陷,采用遗传算法和禁忌搜索的混合策略对FCM进行改进,该策略兼具了这两种算法的优势,改进后的算法自动生成最佳聚类数,优化初始聚类的选择,增强算法的爬山能力,有效改善了算法的性能.将改造前后的两种算法用于网络入侵检测实验,实验结果表明,改造后的算法产生的聚类质量明显优于原算法,用新算法对入侵检测建模,提高了模型的自适应性和实用性.     

混合属性数据流的两阶段入侵检测算法

以KDDCUP99-10%网络入侵数据集作为数据流,提出一种混合属性数据流的两阶段入侵检测算法。通过增量聚类提取数据流的代表信息,根据提出的加权模糊簇特征对增量聚类结果做模糊聚类,簇数可动态改变。理论分析和实验结果表明,该算法可以有效检测数据流入侵。     

基于量子粒子群优化的网络入侵检测算法

提出了一种将量子粒子群优化算法和半监督模糊核聚类算法相结合的混合算法,用以解决入侵检测算法中模糊聚类算法对初始值敏感,容易陷入局部最优的问题。该算法对少量标记数据进行监督聚类得到正确模型,运用这个模型指导大量未标记数据进行聚类,扩充标记数据集合,对仍没有确定标记的数据利用量子粒子群优化的模糊核聚类算法进行聚类,确定其标记类型。通过KDD CUP99实验数据的仿真,实验结果表明,该算法在入侵检测中能获得理想的检测率和误检率。     

基于目标协同规划的网络入侵特征聚类仿真

在网络入侵检测优化的研究中,对网络入侵特征进行准确检测,由于在复杂的网络环境中会存在大量噪声,传统的方法只是单一的入侵特征聚类方法,难以在包含大量噪声的复杂网络环境中进行入侵特征聚类.提出一种基于目标协同规划思想的网络入侵特征聚类方法.利用标准化处理过程和归一化处理过程对对网络入侵数据进行预处理,能够将原始的网络入侵特征属性映射到标准属性空间.提取入侵特征构成数据集合,并进行降维处理,为入侵特征的聚类提供了准确数据基础,将可能性模糊聚类算法和聚类中心分离的模糊聚类算法进行入侵特征聚类目标的协同规划,能够得到准确的聚类中心.实验结果表明,改进算法能够提高网络入侵聚类的准确率.     

基于CS算法优化的模糊C均值聚类入侵检测

针对模糊C均值聚类算法受初始聚类中心影响过大以及易于陷入局部极值的问题,采用具有Levy flight模式且具有很强全局搜索能力的布谷鸟搜索算法,对模糊C均值聚类算法初始聚类中心进行优化,并把优化后的模糊C均值聚类算法应用于网络入侵检测。实验结果显示,经过优化后的模糊C均值聚类算法具有较好的运行速度和聚类效果,对入侵行为的检测效果良好。     

粒子群模糊聚类算法在入侵检测中的研究

目前模糊C均值聚类算法广泛应用于入侵检测算法中,但是存在聚类数目难以确定,目标函数的局部极小点使得算法容易陷入局部最优的现象,影响入侵检测的准确率。鉴于此,文中提出一种基于粒子群算法的模糊聚类算法,引入PSO全局搜索能力和粒子翻转变异操作,避免传统C均值聚类算法对孤立点敏感,容易陷入局部最优,过早收敛的问题。最后通过实验结果表明,新算法检测率明显优于C均值聚类算法,能很好地应用于目前入侵检测系统之中。     

一种基于CFCM的集群入侵检测方法的研究

将网络数据流聚类来实现负载平衡已经被广泛应用于集群入侵检测方法中.将相关性思想引入传统模糊G-均值聚类算法(FCM),给出数据流逻辑距离公式,提出了一种相关模糊C-均值聚类算法(CFCM).最后,将此算法应用于集群入侵检测方法中,利用KDD Cup 1999数据集进行实验,验证其可行性及准确性.     

基于PSO模糊聚类算法的入侵检测研究

提出一种将粒子群优化（PSO）和FCM 相结合的聚类算法PSOFCA对入侵检测系统进行研究,克服FCM方法自身对初始值敏感、容易陷入局部最优等问题。最后对实验数据进行仿真实验,并将实验结果与其他算法结果相比较,结果表明PSOFCA算法在入侵检测中能获得较好的检测能力。     

基于PSO的模糊K-Prototypes聚类

模糊K-Prototypes(FKP)算法能够对包含数值属性和分类属性相混合的数据集进行有效聚类,但是存在对初始值敏感、容易陷入局部极小值的问题.为了克服该缺点,提出了一种基于粒子群优化(PSO)算法和FKP算法的混合聚类算法,先利用PSO算法确定FKP的初始聚类中心,再将PSO聚类结果作为后续FKP算法的初始值.实验结果表明,新算法具有良好的收敛性和稳定性,聚类效果优于单一使用FKP算法.     

Hybrid chemical reaction based metaheuristic with fuzzy c-means algorithm for optimal cluster analysis

Hybridization of two or more algorithms has always been a keen interest of research due to the quality of improvement in searching capability. Taking the positive insights of both the algorithms, the developed hybrid algorithm tries to minimize the substantial limitations. Clustering is an unsupervised learning method, which groups the data according to their similar or dissimilar properties. Fuzzy c-means (FCM) is one of the popularly used clustering algorithms and performs better as compared to other clustering techniques such as k-means. However, FCM possesses certain limitations such as premature trapping at local minima and high sensitivity to the cluster center initialization. Taking these issues into consideration, this research proposes a novel hybrid approach of FCM with a recently developed chemical based metaheuristic for obtaining optimal cluster centers. The performance of the proposed approach is compared in terms of cluster fitness values, inter-cluster distance and intra-cluster distance with other evolutionary and swarm optimization based approaches. A rigorous experimentation is simulated and experimental result reveals that the proposed hybrid approach is performing better as compared to other approaches.     

Modified possibilistic fuzzy C-means algorithms for segmentation of magnetic resonance image

The brain magnetic resonance (MR) image has an embedded bias field. This field needs to be corrected to obtain the actual MR image for classification. Bias field, being a slowly varying nonlinear field, needs to be estimated. In this paper, we have proposed three schemes and in turn three algorithms to segment the given MR image while estimating the bias field. The problem is compounded when the MR image is corrupted with noise in addition to the inherent bias field. The notions of possibilistic and fuzzy membership have been combined to take care of the modeling of the bias field and noise. The weighted typicality measure together with the weighted fuzzy membership has been used to model the image. The above resulted in the proposed Bias Corrected Possibilistic Fuzzy C-Means (BCPFCM) strategy and the algorithm. Further reinforcing the neighbourhood data to the modeling aspect has resulted in the two other strategies namely Bias Corrected Possibilistic Neighborhood Fuzzy C-Means (BCPNFCM) and Bias Corrected Separately weighted Possibilistic Neighborhood Fuzzy C-Means (BCSPNFCM). The proposed algorithms have successfully been tested with synthetic data with bias field of low and high spatial frequency. Noisy brain MR images with Gaussian Noise of varying strength have been considered from the BrainWeb database. The algorithms have also been tested on real brain MR data set with axial and sagittal view and it has been found that the proposed algorithms produced segmentation results with less percentage of misclassification errors as compared to the Bias Corrected Fuzzy C-Means (BCFCM) algorithm proposed by Ahmed et al. [4]. The performance of the proposed algorithms has been compared with algorithms from other paradigm in the context of Tanimoto's index.     

Identification of the linear parts of nonlinear systems for fuzzy modeling

In direct approach to fuzzy modeling, structure identification is one of the most critical tasks. In modeling the nonlinear system, this fact is more crucial. In this paper, a new hybrid method is proposed to cluster the data located in the linear parts on the nonlinear systems. The proposed method can partition the input–output data in two groups: data located in the linear parts and data in the extrema. It is shown that the first group of data is suitable to be clustered by Fuzzy C-Regression Model (FCRM) clustering algorithm and the second group by Fuzzy C-Means (FCM). Then, based on the above findings, a new hybrid clustering algorithm is proposed. Finally, the proposed approach is tested and validated by several numerical examples of nonlinear functions.     

蚁群优化与模糊聚类结合的文本聚类研究

针对模糊文本聚类算法（FCM）对输入顺序以及初始点敏感的问题,提出了一种使用蚁群优化的模糊聚类算法（FACA）。该算法采用蚁群聚类算法（ACA）找到聚类的初始中心点,以解决模糊聚类的输入顺序以及初始点敏感等问题。模糊文本聚类算法的线性复杂度使其更便于在计算机实现。与经典的基本模糊聚类以及蚁群聚类在真实数据集上仿真相比较,结果表明经蚁群优化过的模糊聚类算法（FACA）效果更有效,更适合应用于大型的数据集。     

Generalized rough fuzzy c-means algorithm for brain MR image segmentation

Fuzzy sets and rough sets have been widely used in many clustering algorithms for medical image segmentation, and have recently been combined together to better deal with the uncertainty implied in observed image data. Despite of their wide spread applications, traditional hybrid approaches are sensitive to the empirical weighting parameters and random initialization, and hence may produce less accurate results. In this paper, a novel hybrid clustering approach, namely the generalized rough fuzzy c-means (GRFCM) algorithm is proposed for brain MR image segmentation. In this algorithm, each cluster is characterized by three automatically determined rough-fuzzy regions, and accordingly the membership of each pixel is estimated with respect to the region it locates. The importance of each region is balanced by a weighting parameter, and the bias field in MR images is modeled by a linear combination of orthogonal polynomials. The weighting parameter estimation and bias field correction have been incorporated into the iterative clustering process. Our algorithm has been compared to the existing rough c-means and hybrid clustering algorithms in both synthetic and clinical brain MR images. Experimental results demonstrate that the proposed algorithm is more robust to the initialization, noise, and bias field, and can produce more accurate and reliable segmentations.     

A new Kernelized hybrid c-mean clustering model with optimized parameters

A possibilistic approach was initially proposed for c-means clustering. Although the possibilistic approach is sound, this algorithm tends to find identical clusters. To overcome this shortcoming, a possibilistic Fuzzy c-means algorithm (PFCM) was proposed which produced memberships and possibilities simultaneously, along with the cluster centers. PFCM addresses the noise sensitivity defect of Fuzzy c-means (FCM) and overcomes the coincident cluster problem of possibilistic c-means (PCM). Here we propose a new model called Kernel-based hybrid c-means clustering (KPFCM) where PFCM is extended by adopting a Kernel induced metric in the data space to replace the original Euclidean norm metric. Use of Kernel function makes it possible to cluster data that is linearly non-separable in the original space into homogeneous groups in the transformed high dimensional space. From our experiments, we found that different Kernels with different Kernel widths lead to different clustering results. Thus a key point is to choose an appropriate Kernel width. We have also proposed a simple approach to determine the appropriate values for the Kernel width. The performance of the proposed method has been extensively compared with a few state of the art clustering techniques over a test suit of several artificial and real life data sets. Based on computer simulations, we have shown that our model gives better results than the previous models.     

基于密度函数加权的模糊C均值聚类算法研究

模糊聚类算法具有较强的实用性,但传统模糊C均值算法（FCM）具有对样本集进行等划分趋势的缺陷,没有考虑不同样本的实际分布对聚类效果的影响,当数据集中各样本密集程度相差较大时,聚类结果不是很理想。因此,提出一种基于密度函数加权的模糊C均值聚类算法（DFCM算法）,该算法利用数据对象的密度函数作为每个数据点权值。实验结果表明,与传统的模糊C均值算法相比,DFCM算法具有较好的聚类效果。     

量子遗传算法的模糊K-prototypes聚类

聚类分析是数据挖掘中应用最多的一种技术,它在许多领域都有重要应用。模糊h-prototypes算法是当前聚类分析中最有效算法之一,但是存在对初始值敏感、容易陷入局部极小值的问题。为了克服该缺点,提出了一种基于量子遗传算法和FKP算法的混合聚类算法,首先利用量子遗传算法确定FKP的初始聚类中心,再将量子遗传算法聚类结果作为后续FKP算法的初始值。实验结果显示,算法具有良好的收敛性和稳定性,聚类效果优于单一使用FKP算法和相关改进的算法。