基于带特征染色体遗传算法的支持向量机特征选择和参数优化

鉴于支持向量机特征选择和参数优化对其分类准确率有重大的影响,将支持向量机渐近性能融入遗传算法并生成特征染色体,从而将遗传算法的搜索导向超参数空间中的最佳化误差直线.在此基础上,提出一种新的基十带特征染色体遗传算法的方法,同时进行支持向量机特征选择和参数优化.在与网格搜索、不带特征染色体遗传算法和其他方法的比较中,所提出的方法具有较高的准确率、更小的特征子集和更少的处理时间.     

采用S变换特征选择方法的心律失常分类

针对短时傅里叶变换与小波变换对心电图（Electrocardiogram,ECG）信号特征提取不足以及心律失常识别困难的问题,提出了一种基于S变换特征选择的心律失常分类算法。首先对ECG信号进行S变换,并从幅值和相位两个角度提取ECG信号的时频特征,与形态特征和RR间隔组成原始特征向量。然后将遗传算法与支持向量机（Support vector machine,SVM）结合组成Wrapper式特征选择方法,并在其中融入ReliefF算法,即采用ReliefF算法计算特征权重,并根据特征权重大小来指导遗传算法种群初始化,遗传算法以SVM的分类性能作为适应度函数来搜索特征子集。最后使用"一对多"（One against all,OAA）SVM对MIT-BIH心律失常数据库8种类型心拍进行分类。实验结果表明,该算法达到了较好的分类效果,灵敏度、特异性和准确率分别为96.14%,99.75%和99.81%。     

Gene selection using genetic algorithm and support vectors machines

In this paper, we present a gene selection method based on genetic algorithm (GA) and support vector machines (SVM) for cancer classification. First, the Wilcoxon rank sum test is used to filter noisy and redundant genes in high dimensional microarray data. Then, the different highly informative genes subsets are selected by GA/SVM using different training sets. The final subset, consisting of highly discriminating genes, is obtained by analyzing the frequency of appearance of each gene in the different gene subsets. The proposed method is tested on three open datasets: leukemia, breast cancer, and colon cancer data. The results show that the proposed method has excellent selection and classification performance, especially for breast cancer data, which can yield 100% classification accuracy using only four genes.     

基于遗传算法和支持向量机的肿瘤分子分类

提出了一种基于遗传算法(GA)和支持向量机(SVM)的用于肿瘤分子分类和特征基因选择的新方法。该方法针对基因表达数据样本少维数高的特点,先根据基因的散乱度滤掉大量分类无关基因,而后使用相关性分析去除分类冗余基因,得到一个候选基因子集,用遗传算法搜索候选特征基因空间,发现在支持向量机分类器上具有好的分类性能的且含基因个数较少的特征子集。把这种GA/SVM方法应用到结肠癌和急性白血病基因表达谱,能选出多个取得较高分类精度的较小基因子集,实验结果表明了该方法的有效性。     

An effective feature selection method for hyperspectral image classification based on genetic algorithm and support vector machine

With the development and popularization of the remote-sensing imaging technology, there are more and more applications of hyperspectral image classification tasks, such as target detection and land cover investigation. It is a very challenging issue of urgent importance to select a minimal and effective subset from those mass of bands. This paper proposed a hybrid feature selection strategy based on genetic algorithm and support vector machine (GA–SVM), which formed a wrapper to search for the best combination of bands with higher classification accuracy. In addition, band grouping based on conditional mutual information between adjacent bands was utilized to counter for the high correlation between the bands and further reduced the computational cost of the genetic algorithm. During the post-processing phase, the branch and bound algorithm was employed to filter out those irrelevant band groups. Experimental results on two benchmark data sets have shown that the proposed approach is very competitive and effective.     

Modified binary PSO for feature selection using SVM applied to mortality prediction of septic patients

This paper proposes a modified binary particle swarm optimization (MBPSO) method for feature selection with the simultaneous optimization of SVM kernel parameter setting, applied to mortality prediction in septic patients. An enhanced version of binary particle swarm optimization, designed to cope with premature convergence of the BPSO algorithm is proposed. MBPSO control the swarm variability using the velocity and the similarity between best swarm solutions. This paper uses support vector machines in a wrapper approach, where the kernel parameters are optimized at the same time. The approach is applied to predict the outcome (survived or deceased) of patients with septic shock. Further, MBPSO is tested in several benchmark datasets and is compared with other PSO based algorithms and genetic algorithms (GA). The experimental results showed that the proposed approach can correctly select the discriminating input features and also achieve high classification accuracy, specially when compared to other PSO based algorithms. When compared to GA, MBPSO is similar in terms of accuracy, but the subset solutions have less selected features.     

Housing price forecasting based on genetic algorithm and support vector machine

Accurate forecasting for future housing price is very significant for socioeconomic development and national lives. In this study, a hybrid of genetic algorithm and support vector machines (G-SVM) approach is presented in housing price forecasting. Support vector machine (SVM) has been proven to be a robust and competent algorithm for both classification and regression in many applications. However, how to select the most appropriate the training parameter value is the important problem in the using of SVM. Compared to Grid algorithm, genetic algorithm (GA) method consumes less time and performs well. Thus, GA is applied to optimize the parameters of SVM simultaneously. The cases in China are applied to testify the housing price forecasting ability of G-SVM method. The experimental results indicate that forecasting accuracy of this G-SVM approach is more superior than GM.     

Automatic detection of erythemato-squamous diseases using PSO–SVM based on association rules

In this paper, we develop a diagnosis model based on particle swarm optimization (PSO), support vector machines (SVMs) and association rules (ARs) to diagnose erythemato-squamous diseases. The proposed model consists of two stages: first, AR is used to select the optimal feature subset from the original feature set; then a PSO based approach for parameter determination of SVM is developed to find the best parameters of kernel function (based on the fact that kernel parameter setting in the SVM training procedure significantly influences the classification accuracy, and PSO is a promising tool for global searching). Experimental results show that the proposed AR_PSO–SVM model achieves 98.91% classification accuracy using 24 features of the erythemato-squamous diseases dataset taken from UCI (University of California at Irvine) machine learning database. Therefore, we can conclude that our proposed method is very promising compared to the previously reported results.     

Parameter determination of support vector machine and feature selection using simulated annealing approach

Support vector machine (SVM) is a novel pattern classification method that is valuable in many applications. Kernel parameter setting in the SVM training process, along with the feature selection, significantly affects classification accuracy. The objective of this study is to obtain the better parameter values while also finding a subset of features that does not degrade the SVM classification accuracy. This study develops a simulated annealing (SA) approach for parameter determination and feature selection in the SVM, termed SA-SVM.To measure the proposed SA-SVM approach, several datasets in UCI machine learning repository are adopted to calculate the classification accuracy rate. The proposed approach was compared with grid search which is a conventional method of performing parameter setting, and various other methods. Experimental results indicate that the classification accuracy rates of the proposed approach exceed those of grid search and other approaches. The SA-SVM is thus useful for parameter determination and feature selection in the SVM.     

融合渐近性的灰狼优化支持向量机模型

大数据的发展对数据分类领域的分类准确性有了更高的要求;支持向量机(Support Vector Machine,SVM)的广泛应用需要一种高效的方法来构造一个分类能力强的SVM分类器;SVM的核函数参数与惩罚因子以及特征子集对预测模型的复杂度和预测精度有着重要影响。为提高SVM的分类性能,文中将SVM的渐近性融合到灰狼优化(Grey Wolf Optimization,GWO)算法中,提出了新的SVM分类器模型,该模型对SVM的参数与数据的特征子集同时进行优化,融合SVM渐近性的新灰狼个体将灰狼优化算法的搜索空间导向超参数空间中的最佳区域,能够更快地获得最优解;此外,将获得的分类准确率、所选特征个数和支持向量个数相结合,提出了一种新的适应度函数,新的适应度函数与融合渐近性的灰狼优化算法将搜索引向最优解。采用UCI中的多个经典数据集对所提模型进行验证,将其与网格搜素算法、未融合渐近性的灰狼优化算法以及其他文献中的方法进行对比,其分类准确率在不同数据集上均有不同程度的提升。实验结果表明,所提算法能找到SVM的最优参数与最小特征子集,具有更高的分类准确率和更短的平均处理时间。     

Comparison study on the performance of the multi classifiers with hybrid optimal features selection method for medical data diagnosis

Features subset selection (FSS) generally plays an essential role in the implementation of data mining, particularly in the field of high-dimensional medical data analysis, as well as in supplying early detection with essential features and high accuracy. The latest modern feature selection models are now using the ability of optimization algorithms for extracting features of particular properties to get the highest accuracy performance possible. Many of the optimization algorithms, such as genetic algorithm, often use the required parameters that would need to be adjusted for better results. For the function selection procedure, tuning these parameter values is a difficult challenge. In this paper, a new wrapper-based feature selection approach called binary teaching learning based optimization (BTLBO) is introduced. The binary teaching learning based optimization (BTLBO) is among the most sophisticated meta-heuristic method which does not involve any specific algorithm parameters. It requires only standard process parameters such as population size and a number of iterations to extract a set of features selected from a data. This is a demanding process, to achieve the best possible set of features would be to use a method which is independent of the method controlling parameters. This paper introduces a new modified binary teaching–learning-based optimization (NMBTLBO) as a technique to select subset features and demonstrate support vector machine (SVM) accuracy of binary identification as a fitness function for the implementation of the feature subset selection process. The new proposed algorithm NMBTLBO contains two steps: first, the new updating procedure, second, the new method to select the primary teacher in teacher phase in binary teaching-learning based on optimization algorithm. The proposed technique NMBTLBO was used to classify the rheumatic disease datasets collected from Baghdad Teaching Hospital Outpatient Rheumatology Clinic during 2016–2018. Compared with the original BTLBO algorithm, the improved NMBTLBO algorithm has achieved a major difference in accuracy. Validation was carried out by testing the accuracy of four classification methods: K-nearest neighbors, decision trees, support vector machines and K-means. Study results showed that the classification accuracy of the four methods was increased for the proposed method of selection of features (NMBTLBO) compared to the BTLBO algorithm. SVM classifier provided 89% accuracy of BTLBO-SVM and 95% with NMBTLBO –SVM. Decision trees set the values of 94% with BTLBO-SVM and 95% with the feature selection of NMBTLBO-SVM. The analysis indicates that the latest method (NMBTLBO) enhances classification accuracy.

     

A distributed PSO–SVM hybrid system with feature selection and parameter optimization

This study proposed a novel PSO–SVM model that hybridized the particle swarm optimization (PSO) and support vector machines (SVM) to improve the classification accuracy with a small and appropriate feature subset. This optimization mechanism combined the discrete PSO with the continuous-valued PSO to simultaneously optimize the input feature subset selection and the SVM kernel parameter setting. The hybrid PSO–SVM data mining system was implemented via a distributed architecture using the web service technology to reduce the computational time. In a heterogeneous computing environment, the PSO optimization was performed on the application server and the SVM model was trained on the client (agent) computer. The experimental results showed the proposed approach can correctly select the discriminating input features and also achieve high classification accuracy.     

A crowding multi-objective genetic algorithm for image parsing

Image parsing is a process of understanding the contents of an image. The process normally involves labeling pixels or superpixels of a given image with classes of objects that may exist in the image. The accuracy of such labeling for the existing methodologies still needs to be improved. The parsing method needs to be able to identify multiple instances of objects of different classes and sizes. In our previous work, a novel feature representation for an instance of objects in an image was proposed for object recognition and image parsing. The feature representation consists of the histogram vector of 2 g of visual word ids of the two successive clockwise neighbors of any superpixels in the object instance and the shape vector of the instance. Using the feature representation, the instance can be classified with very high accuracy by the per class support vector machines (SVMs). A multi-objective genetic algorithm is also proposed to find a subset of image segments that would best constitute an instance for a class of objects, i.e., maximizing the SVM classification score and the size of the instance. However, the genetic algorithm can only identify a single instance for each class of objects, despite the fact that many instances of the same class may exist. In this paper, a crowding genetic algorithm is used instead to search for multiple optimal solutions and help alleviate this deficiency. The experimental results show that this crowding genetic algorithm performs better than the previously proposed method as well as the existing methodologies, in terms of class-wise and pixel-wise accuracy. The qualitative results also clearly show that this method can effectively identify multiple object instances existing in a given image.     

Evolving artificial neural network structure using grammar encoding and colonial competitive algorithm

Generalization performance of support vector machines (SVM) with Gaussian kernel is influenced by its model parameters, both the error penalty parameter and the Gaussian kernel parameter. After researching the characteristics and properties of the parameter simultaneous variation of support vector machines with Gaussian kernel by the parameter analysis table, a new area distribution model is proposed, which consists of optimal straight line, reference point of area boundary, optimal area, transition area, underfitting area, and overfitting area. In order to improve classification performance of support vector machines, a genetic algorithm based on change area search is proposed. Comparison experiments show that the test accuracy of the genetic algorithm based on change area search is better than that of the two-linear search method.     

基于优化的支持向量机的机械设备多故障诊断模型

提出了一种基于遗传算法优化支持向量机的故障诊断模型.它利用遗传算法对支持向量机同时对传统的时域特征参量子集和核参数同时优化,以达到选择最优的设备故障主导特征参数组合的目的,实现对机器不同类型故障的识别.对齿轮故障诊断的结果表明它有效提高了多分类支持向量机的故障分类准确性.     

Hybrid Harmony Search Combined with Stochastic Local Search for Feature Selection

Feature selection is a challenging task that has been the subject of a large amount of research, especially in relation to classification tasks. It permits to eliminate the redundant attributes and enhance the classification accuracy by keeping only the relevant attributes. In this paper, we propose a hybrid search method based on both harmony search algorithm (HSA) and stochastic local search (SLS) for feature selection in data classification. A novel probabilistic selection strategy is used in HSA–SLS to select the appropriate solutions to undergo stochastic local refinement, keeping a good compromise between exploration and exploitation. In addition, the HSA–SLS is combined with a support vector machine (SVM) classifier with optimized parameters. The proposed HSA–SLS method tries to find a subset of features that maximizes the classification accuracy rate of SVM. Experimental results show good performance in favor of our proposed method.     

Feature selection for hyperspectral data based on recursive support vector machines

In this article, a feature selection algorithm for hyperspectral data based on a recursive support vector machine (R‐SVM) is proposed. The new algorithm follows the scheme of a state‐of‐the‐art feature selection algorithm, SVM recursive feature elimination or SVM‐RFE, and uses a new ranking criterion derived from the R‐SVM. Multiple SVMs are used to address the multiclass problem. The algorithm is applied to Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data to select the most informative bands and the resulting subsets of the bands are compared with SVM‐RFE using the accuracy of classification as the evaluation of the effectiveness of the feature selection. The experimental results for an agricultural case study indicate that the feature subset generated by the newly proposed algorithm is generally competitive with SVM‐RFE in terms of classification accuracy and is more robust in the presence of noise.     

Credit scoring using support vector machines with direct search for parameters selection

Support vector machines (SVM) is an effective tool for building good credit scoring models. However, the performance of the model depends on its parameters’ setting. In this study, we use direct search method to optimize the SVM-based credit scoring model and compare it with other three parameters optimization methods, such as grid search, method based on design of experiment (DOE) and genetic algorithm (GA). Two real-world credit datasets are selected to demonstrate the effectiveness and feasibility of the method. The results show that the direct search method can find the effective model with high classification accuracy and good robustness and keep less dependency on the initial search space or point setting.     

特征选择在隐秘图像检测中的应用

提出一种基于遗传算法和多超球面一类支持向量机的隐秘图像检测方案。为了得到最能反映分类本质的特征从而有效实现分类识别,采用遗传算法进行图像特征选择,将支持向量机的分类效果作为适应度函数值返回,指导遗传算法搜索最优的特征选择方案。实验结果表明,与仅采用支持向量机分类而未进行特征选择的隐秘检测方案相比,该方案提高了隐秘图像检测的识别率。     

基于改进斑点鬣狗优化算法的同步优化特征选择

针对传统支持向量机（SVM）在封装式特征选择中分类精度低、特征子集选择冗余以及计算效率差的不足,利用元启发式优化算法同步优化SVM与特征选择。为改善SVM分类效果以及选择特征子集的能力,首先,利用自适应差分进化（DE）算法、混沌初始化与锦标赛选择策略对斑点鬣狗优化（SHO）算法改进,以增强其局部搜索能力并提高其寻优效率与求解精度;其次,将改进后的算法用于特征选择与SVM参数调整的同步优化中;最后,在UCI数据集进行特征选择仿真实验,采取分类准确率、选择特征数、适应度值及运行时间来综合评估所提算法的优化性能。实验结果证明,改进算法的同步优化机制能够在高分类准确率下降低特征选择的数目,该算法比传统算法更适合解决封装式特征选择问题,具有良好的应用价值。