一种新型的克隆选择算法*

针对克隆选择算法自适应能力较弱的缺陷,给出了一种基于危险理论的自适应克隆选择算法。设计了危险信号操作算子,该算子将种群浓度的变动作为环境因素,以抗体—抗原亲和力为依据计算各个抗体在该环境因素下的危险信号,最终通过危险信号自适应地引导免疫克隆、变异和选择等后续免疫应答。实验结果表明本文算法具有较好的自适应能力和多值搜索能力。     

一种免疫克隆选择算法在BP网络学习中的应用

在分析BP网络学习存在的问题后,采用了一种免疫克隆选择算法对BP网络的权值进行优化学习,并提出了一种新的变异方法,该变异方法可以根据亲和力的大小自适应调整抗体变异的幅度,与传统的高斯变异相比,不但简化了抗体的编码,还很好地体现了克隆选择算法抗体变异的特点,提高了算法的搜索能力和收敛性能。仿真实验表明,基于这种变异方法的免疫克隆选择算法可以很好地提高BP网络的学习速度,有效地避免算法过早收敛的问题。     

免疫算法优化的大气质量评价模型及其应用

针对传统免疫克隆选择算法搜索精度不高的不足,提出了一种改进的免疫克隆选择算法,即引入疫苗接种策略和局部高斯变异算子的免疫克隆选择算法.在疫苗提取、选取和接种过程中引入轮盘赌选择、二进制位基因位选取和接种策略,克服了传统免疫克隆选择算法没有抗体基因交叉的现象,提高了产生优良抗体的比率;通过引入局部高斯变异算子,利用高斯变异的小步长不断地自适应调整,提高了算法的局部搜索能力.此外,算法还采用了扩大搜索空间策略,避免算法陷入局部极值,提高了算法的全局搜索能力.在此基础上,提出了基于免疫克隆选择算法的大气质量评价模型,并将其应用于大气质量评价领域.实验结果表明,该算法有效地提高了求解问题的精度和执行效率,提出的评价模型具有较好的实用性和应用前景.     

基于免疫粒子群的嵌入式系统软硬件划分方法

针对嵌入式系统软硬件划分问题,提出一种粒子群算法与免疫克隆选择算法相结合的免疫粒子群软硬件划分方法。该算法重新定义了亲和力、克隆算子、变异算子和选择算子,有效克服了粒子群算法容易陷入局部最优的缺点。仿真实验表明该算法有效提高了解的精度,获得了更合理的软硬件划分结果。     

一种并行免疫进化策略算法研究

基于克隆选择原理,提出一种自适应并行免疫进化策略．在算法中根据抗体抗原亲和度将初始抗体种群分为两个子群,相应地提出了精英克隆算子和超变异算子．通过精英克隆算子提高算法局部搜索能力,同时利用超变异算子维持种群多样性,通过这两个功能互补算子的并行操作实现种群进化．仿真表明,自适应并行免疫进化策略搜索效率高,能有效抑制早熟收敛现象,可用于解决复杂机器学习问题．     

一种新型的免疫多目标优化算法

免疫算法借鉴了生物免疫系统独有的自适应、自组织、多样性、免疫记忆等优良特性,是智能计算领域中继人工神经网络和进化计算之后的又一个研究热点.提出一种新型的基于聚类的免疫多目标优化算法(CMOIA),借鉴了免疫算法的亲和度定义,由此亲和度定义的免疫变异操作子使得算法产生的抗体群体能够逐渐向精英群体变异,结合进化算法在局部搜索中维持解个体多样性的能力对免疫变异产生的抗体群进行交叉变异操作,采用一种基于聚类的克隆选择算子来保持免疫算法在探测新解和加强局部搜索之间的平衡.选取了8个通用的多目标优化问题对3个广泛采用的性能指标进行了测试.与现有两个经典的进化优化算法相比较,算法所产生的解集在收敛性、多样性等方面显示了相当的独创性和先进性.     

新型免疫遗传算法研究

针对现存免疫遗传算法存在的不足,提出基于免疫网络及其动力学模型的新型免疫遗传算法。以激励水平作为抗体选择操作的量度,采用欧几里德距离计算亲和力,并构建精英抗体库以便给精英抗体更多交叉变异的机会。仿真实验证明,该算法比传统遗传算法具有更强的全局搜索能力和计算效率,收敛速度也更快。     

自适应多模态免疫进化算法的研究与实现

基于免疫系统的动力学模型,根据一类抗体可结合多个抗原表位并逐步达到亲和度成熟的机理,研究并实现了一种多模态免疫进化算法(MIEA)．算法的主要算子包括正选择、记忆细胞产生、超变异和抗体相似性抑制．对不同的多峰值函数进行的仿真实验证明,算法能够找到多模态问题的全部最优解或尽可能多的局部最优解．通过与同类算法进行比较和计算复杂性分析表明,该算法不仅计算量小、具有更好的搜索性能,而且无需任何先验知识,可实现真正的自适应搜索．     

一种基于双变异算子的免疫网络算法

针对遗传算法难以解决多峰函数优化的问题,提出一种基于双变异算子的免疫网络算法.该算法借鉴免疫系统的克隆选择和免疫网络理论,采用双变异算子提高算法的全局和局部搜索能力.利用动态网络抑制策略保持神群的多样性,自适应地调节抗体群的规模.仿真结果表明,该算法能有效地改善种群的多样性,较好地实现全局优化与局部优化的有机结合,具有更强的多峰函数优化能力.     

一种基于抗体网络的免疫算法

阐述了免疫系统抗体网络的机理和特点,深入分析了抗体网络与常用的免疫算法和Hopfield神经网络异同.通过不断更新输入模式(抗原)和采用最优保存策略,将基于克隆选择的竞争学习算子、自动生成网络结构、剪枝算子和低频变异用于进化操作,提出一种新的基于抗体网络的免疫算法,用于函数优化问题.实验结果表明新算法可行有效.与常用的免疫算法、Hopfield神经网络优化算法比较,新算法具有较好的全局搜索能力和较快收敛速度.     

Usage of class dependency based feature selection and fuzzy weighted pre-processing methods on classification of macular disease

In this paper, we propose a new feature selection method called class dependency based feature selection for dimensionality reduction of the macular disease dataset from pattern electroretinography (PERG) signals. In order to diagnosis of macular disease, we have used class dependency based feature selection as feature selection process, fuzzy weighted pre-processing as weighted process and decision tree classifier as decision making. The proposed system consists of three parts. First, we have reduced to 9 features number of features of macular disease dataset that has 63 features using class dependency based feature selection, which is first developed by ours. Second, the macular disease dataset that has 9 features is weighted by using fuzzy weighted pre-processing. And finally, decision tree classifier was applied to PERG signals to distinguish between healthy eye and diseased eye (macula diseases). The employed class dependency based feature selection, fuzzy weighted pre-processing and decision tree classifier have reached to 96.22%, 96.27% and 96.30% classification accuracies using 5–10–15-fold cross-validation, respectively. The results confirmed that the medical decision making system based on the class dependency based feature selection, fuzzy weighted pre-processing and decision tree classifier has potential in detecting the macular disease. The stated results show that the proposed method could point out the ability of design of a new intelligent assistance diagnosis system.     

自调优自适应遗传算法的WKNN特征选择方法

针对大多已有基于[K]近邻和遗传算法的特征选择方法中没有考虑各个特征的重要度不同,并且容易出现过早收敛,特别是局部最优解问题,提出了一种基于自调优自适应遗传算法的WKNN特征选择方法。该方法使用WKNN算法预测样本的类别,为每个特征分配一个权重来衡量特征的分类能力,然后采用自调优自适应遗传算法,对变异率、种群规模和收敛阈值进行参数调整,在迭代进化过程中搜索最优特征权重向量。为了评价该方法的有效性,与已有7种特征选择方法在5个标准数据集上进行了比较。实验结果表明,该方法是有效的,且具有较高的分类性能。     

A novel hybrid algorithm for feature selection

Feature selection is an important filtering method for data analysis, pattern classification, data mining, and so on. Feature selection reduces the number of features by removing irrelevant and redundant data. In this paper, we propose a hybrid filter–wrapper feature subset selection algorithm called the maximum Spearman minimum covariance cuckoo search (MSMCCS). First, based on Spearman and covariance, a filter algorithm is proposed called maximum Spearman minimum covariance (MSMC). Second, three parameters are proposed in MSMC to adjust the weights of the correlation and redundancy, improve the relevance of feature subsets, and reduce the redundancy. Third, in the improved cuckoo search algorithm, a weighted combination strategy is used to select candidate feature subsets, a crossover mutation concept is used to adjust the candidate feature subsets, and finally, the filtered features are selected into optimal feature subsets. Therefore, the MSMCCS combines the efficiency of filters with the greater accuracy of wrappers. Experimental results on eight common data sets from the University of California at Irvine Machine Learning Repository showed that the MSMCCS algorithm had better classification accuracy than the seven wrapper methods, the one filter method, and the two hybrid methods. Furthermore, the proposed algorithm achieved preferable performance on the Wilcoxon signed-rank test and the sensitivity–specificity test.     

基于加权信息增益的恶意代码检测方法

采用数据挖掘技术检测恶意代码,提出一种基于加权信息增益的特征选择方法。该方法综合考虑特征频率和信息增益的作用,能够更加准确地选取有效特征,从而提高检测性能。实现一个恶意代码检测系统,采用二进制代码的N-gram和变长N-gram作为特征提取方法,加权信息增益作为特征选择方法,使用多种分类器进行恶意代码检测。实验结果证明,该方法能有效提高恶意代码的检测率和准确率。     

Human facial expression recognition using curvelet feature extraction and normalized mutual information feature selection

To recognize expressions accurately, facial expression systems require robust feature extraction and feature selection methods. In this paper, a normalized mutual information based feature selection technique is proposed for FER systems. The technique is derived from an existing method, that is, the max-relevance and min-redundancy (mRMR) method. We, however, propose to normalize the mutual information used in this method so that the domination of the relevance or of the redundancy can be eliminated. For feature extraction, curvelet transform is used. After the feature extraction and selection the feature space is reduced by employing linear discriminant analysis (LDA). Finally, hidden Markov model (HMM) is used to recognize the expressions. The proposed FER system (CNF-FER) is validated using four publicly available standard datasets. For each dataset, 10-fold cross validation scheme is utilized. CNF-FER outperformed the existing well-known statistical and state-of-the-art methods by achieving a weighted average recognition rate of 99 % across all the datasets.     

一种基于权重的文本特征选择方法

在分析比较几种常用的特征选择方法的基础上,提出了一种引入文本类区分加权频率的特征选择方法TFIDF_Ci。它将具体类的文档出现频率引入TFIDF函数,提高了特征项所在文档所属类区分其他类的能力。实验中采用KNN分类算法对该方法和其他特征选择方法进行了比较测试。结果表明,TFIDF_Ci方法较其他方法在不同的训练集规模情况下具有更高的分类精度和稳定性。     

An Embedded Feature Selection Method for Imbalanced Data Classification

Imbalanced data is one type of datasets that are frequently found in real-world applications, e.g., fraud detection and cancer diagnosis. For this type of datasets, improving the accuracy to identify their minority class is a critically important issue. Feature selection is one method to address this issue. An effective feature selection method can choose a subset of features that favor in the accurate determination of the minority class. A decision tree is a classifier that can be built up by using different splitting criteria. Its advantage is the ease of detecting which feature is used as a splitting node. Thus, it is possible to use a decision tree splitting criterion as a feature selection method. In this paper, an embedded feature selection method using our proposed weighted Gini index (WGI) is proposed. Its comparison results with Chi2, F-statistic and Gini index feature selection methods show that F-statistic and Chi2 reach the best performance when only a few features are selected. As the number of selected features increases, our proposed method has the highest probability of achieving the best performance. The area under a receiver operating characteristic curve (ROC AUC) and F-measure are used as evaluation criteria. Experimental results with two datasets show that ROC AUC performance can be high, even if only a few features are selected and used, and only changes slightly as more and more features are selected. However, the performance of F-measure achieves excellent performance only if 20% or more of features are chosen. The results are helpful for practitioners to select a proper feature selection method when facing a practical problem.      

基于特征加权的Category ART网络及应用

特征加权是特征选择的一般情况，它能更加细致地区分特征对结果影响的程度，往往能够获得比特征选择更好的或者至少相等的性能。该文采用自适应遗传算法来优化Category ART网络的特征权值，提出了一种改进的Category ART网络FWART。在UCI标准数据集上的实验表明，FWART网络获得了比Category ART网络更好的泛化能力。将该网络应用在地震震型预报上，取得了很好的预报效果。     

一种基于粗糙集文本自动分类的改进算法

自动文本分类的效果在很大程度上依赖于属性特征的选择。针对传统基于频率阈值过滤的特征选择方法会导致有效信息丢失,影响分类精度的不足,提出了一种基于粗糙集的文本自动分类算法。该方法对加权后的特征属性进行离散化,建立一个决策表;根据基于依赖度的属性重要度对决策表中条件属性进行适当的筛选;采用基于条件信息熵的启发式算法实现文本属性特征的约简。实验结果表明,该方法能约简大量冗余的特征属性,在不降低分类精度的同时,提高文本分类的运行效率。     

基于IPSO算法的特征选择与目标识别

为了提高相似目标的分类识别率,实现降维,提出了一种基于改进的粒子群优化(IPSO)的特征选择与目标识别方法。IPSO利用二进制位串来计算位置和速度,并在速度更新公式中增加约束项,权衡识别率与特征维数的比重选择适应度函数。结合距离分类器,用IPSO在自建的相似目标特征库上进行最优特征子集选择及分类实验。实验结果表明了该算法的有效性,在UCI数据集上的对比实验结果表明了IPSO的改进效果。