基于支持向量机的故障诊断方法

提出了基于支持向量机的故障诊断方法和步骤。诊断实例表明，与神经网络故障诊断方法相比，诊断小样本分析的支持向量机故障诊断方法具有分类能力强、推广能力好的特点。     

基于混沌最小二乘支持向量机的软测量建模

提出一种改进算法,用来解决现有最小二乘支持向量机方法在处理大规模样本软测量建模问题时出现的模型结构复杂、失去支持向量稀疏性且正规化参数和核参数难以确定等问题。对样本集进行预处理,通过计算样本间欧氏距离进行样本相似程度分析,去除样本集中1/3的样本以简化支持向量机模型结构并提高计算速度。定义了一种混沌映射构成混沌系统并分析了其遍历性。应用改进的混沌优化算法优化最小二乘支持向量机模型参数以提高模型的拟合精度和泛化能力。将改进算法用于丙烯腈收率软测量建模中,仿真实验结果表明：模型精度较高,泛化性能好,满足现场测量要求。     

基于支持向量机的Windows主机入侵检测系统

提出了一种基于支持向量机的W indow s主机入侵检测方法。讨论了以W indow s注册表作为数据源的入侵检测系统的结构及特征向量的提取方法。给出了基于支持向量机的入侵分类算法,通过建立支持向量描述模型进行预测。实验表明:该方法对已知样本有很高的检测率,对未知样本也有一定检测能力。     

基于支持向量机的化工过程故障诊断

引入了基于统计学习理论的支持向量机技术，以连续搅拌釜式反应器——CSTR模型为例，研究了非线性化工复杂反应过程的故障诊断问题。实验结果表明，支持向量机方法与传统故障诊断方法相比，具有更好的精度、速度以及适应性。     

基于改进克隆选择算法的最小二乘支持向量机

针对最小二乘支持向量机的参数选取问题,引入了克隆选择算法,提出了一种基于改进克隆选择算法的最小二乘支持向量机。同时根据最小二乘支持向量机的学习能力和泛化能力,在克隆选择算法的目标函数中加入两者的动态调节机制,这样改进的克隆选择算法在寻优过程中能够准确、快速地搜索到最小二乘支持向量机的最优参数。将本文模型用于乙烯裂解炉裂解深度值的学习和预测,经仿真实验表明：该预测模型的训练速度快,预测精度高。     

支持向量机在卵巢癌诊断中的应用

支持向量机是在统计学习理论基础上发展而来的一种新的通用学习方法，较好地解决了有限样本的学习分类问题。现阶段卵巢癌的血清学诊断，特别是早期诊断主要依靠CA125，敏感性和特异性均不太理想。本文采用统计学和生物信息学的支持向量机方法建立卵巢癌的CA125、CA72-4、TSGF、VEGF、LPA等5种血清肿瘤标志物的组合模式识别系统，并初步探讨了支持向量机方法对于卵巢癌诊断的可行性。     

基于生物信息特征提取的中医辨证

目的伴随着科技的发展,在多学科交叉的今天,选择合适的计算方法对中医证候进行辨证是实现中医规范化的重要任务。方法将多类支持向量机与基于互信息的特征提取方法相结合,用特征提取方法多源数据进行处理,获得信息量最大的症状组合,然后利用这些症状组合作为多类支持向量机的输入进行分类,根据支持向量机的输出就可得到相应的证候。该方法的有效性通过一个中医实例得到证实。结果通过对各种方法获得的症状组合的正确辨证率对比发现,用基于互信息的特征提取方法获得的症状组合较为理想。结论特征提取的结果优于单纯的基于互信息选择症状组合的结果,同时看出支持向量机适合中医证候的小样本研究,客观说明了互信息、特征提取和支持向量机3种方法的结合适用于中医辨证分类。     

基于广义加权支持向量机的焊接缺陷分类方法

提出了一种广义加权支持向量机（GWSVM）的焊接缺陷分类算法。首先为克服由于样本数量不平衡性引起的小样本类别精度差的问题，引入由于样本差异的权重；然后为解决不同类别的重要性要求，根据经验人工确定不同类别重要性的权重。针对样本重要性的影响，采用有监督模糊聚类方法来确定样本重要性权重。测试结果表明：广义加权支持向量机在噪声影响较大及样本类别相差较大时，能够提高重要的、数量少的缺陷检测精度。     

一种新的支持向量机增量算法

分析了增量学习过程中支持向量和非支持向量的转化情况。在此基础上提出一种误分点回溯SVM增量算法,该算法先找出新增样本中被误分的样本,然后在原样本集寻找距误分点最近的样本作为训练集的一部分,重新构建分类器,这样能有效保留样本的分类信息。实验结果表明:该算法比传统的支持向量机增量算法有更高的分类精度。     

基于多模型模糊核聚类方法的污水处理过程软测量建模

针对污水处理过程高度非线性及强耦合性的特点,基于多个模型的组合可以提高模型精度和鲁棒性的思想,提出了一种基于 模糊核聚类的多最小二乘支持向量机的软测量建模方法。该方法根据不同工况使用模糊核聚类算法对输入数据进行聚类划分,针对 每个聚类子集用最小二乘支持向量机方法建立子模型,最终通过子模型切换策略得到系统输出。在污水处理过程仿真平台展开验证 工作,对生化需氧量BOD的软测量进行建模,获得了良好的实验结果。     

小波核极限学习机及其在醋酸精馏软测量建模中的应用

传统的机器学习算法一般通过迭代进行参数寻优,导致学习速度慢,且容易陷入局部最小值。针对这个问题,提出了一种基于小波核函数的极限学习机（KEML）的软测量建模方法,将支持向量机（SVM）中核函数的思想运用到极限学习机（EML）中,避免了SVM训练速度慢以及ELM算法不稳定的缺点。将KEML算法运用于醋酸精馏的软测量建模问题中,仿真实验结果验证了该算法的学习速度是SVM的92倍,且算法的精度以及模型的泛化能力都有所提高。     

Use of Support Vector Machines and Neural Network in Diagnosis of Neuromuscular Disorders

In this study the performance of support vector machine (SVM)and back-propagation neural network were applied to analyze the classification of the electromyogram (EMG) signals obtained from normal, neuropathy and myopathy subjects. By using autoregressive (AR) modeling, AR coefficients were obtained from EMG signals. Moreover, the support vector machine and artificial neural network (ANN) were used as base classifiers. The AR coefficients were benefited as inputs for SVM and ANN. Besides, these coefficients were tested both in ANN and SVM. The results show that SVM has high anticipation level in the diagnosis of neuromuscular disorders. It is proved that its test performance is high compared with ANN.     

基于混合核函数的PSO-SVM分类算法

在数据挖掘中,支持向量机是被广泛应用的一种分类算法,其核函数的选择及参数的设定没有有效的标准。本文采用混合核函数构造兼顾学习能力和泛化性能的支持向量机算法,并利用粒子群算法来确定支持向量机的参数。应用基于混合核函数的PSO SVM算法对一个经典的分类测试数据集进行分类,将该算法与单一核函数支持向量机算法的分类结果进行比较,结果表明所提出的算法的分类性能有明显提升。     

A decision support system to improve medical diagnosis using a combination of k-medoids clustering based attribute weighting and SVM

The use of machine learning tools has become widespread in medical diagnosis. The main reason for this is the effective results obtained from classification and diagnosis systems developed to help medical professionals in the diagnosis phase of diseases. The primary objective of this study is to improve the accuracy of classification in medical diagnosis problems. To this end, studies were carried out on 3 different datasets. These datasets are heart disease, Parkinson’s disease (PD) and BUPA liver disorders. Key feature of these datasets is that they have a linearly non-separable distribution. A new method entitled k-medoids clustering-based attribute weighting (kmAW) has been proposed as a data preprocessing method. The support vector machine (SVM) was preferred in the classification phase. In the performance evaluation stage, classification accuracy, specificity, sensitivity analysis, f-measure, kappa statistics value and ROC analysis were used. Experimental results showed that the developed hybrid system entitled kmAW?+?SVM gave better results compared to other methods described in the literature. Consequently, this hybrid intelligent system can be used as a useful medical decision support tool.     

基于CBR和SVR的生化需氧量预测模型

针对污水处理过程生化需氧量（BOD）浓度难以实时监测的问题,建立了一种基于支持向量回归机（SVR）修正方法的案例推理（CBR）预测模型。该模型主要包括案例检索、案例重用、SVR修正、案例存储等4个部分,其中,SVR修正模型是利用历史数据构造修正案例库,并采用SVR训练而获得的,可以对传统CBR求解模型得到的BOD浓度建议值进行修正。实验表明本文模型的拟合误差优于支持向量机（SVM）、BP神经网络、RBF神经网络以及传统CBR方法,说明SVR修正方法的引入可以改善CBR的回归性能,提高CBR的学习能力。     

A sequence labeling approach to link medications and their attributes in clinical notes and clinical trial announcements for information extraction

Objective

The goal of this work was to evaluate machine learning methods, binary classification and sequence labeling, for medication–attribute linkage detection in two clinical corpora.

Data and methods

We double annotated 3000 clinical trial announcements (CTA) and 1655 clinical notes (CN) for medication named entities and their attributes. A binary support vector machine (SVM) classification method with parsimonious feature sets, and a conditional random fields (CRF)-based multi-layered sequence labeling (MLSL) model were proposed to identify the linkages between the entities and their corresponding attributes. We evaluated the system''s performance against the human-generated gold standard.

Results

The experiments showed that the two machine learning approaches performed statistically significantly better than the baseline rule-based approach. The binary SVM classification achieved 0.94 F-measure with individual tokens as features. The SVM model trained on a parsimonious feature set achieved 0.81 F-measure for CN and 0.87 for CTA. The CRF MLSL method achieved 0.80 F-measure on both corpora.

Discussion and conclusions

We compared the novel MLSL method with a binary classification and a rule-based method. The MLSL method performed statistically significantly better than the rule-based method. However, the SVM-based binary classification method was statistically significantly better than the MLSL method for both the CTA and CN corpora. Using parsimonious feature sets both the SVM-based binary classification and CRF-based MLSL methods achieved high performance in detecting medication name and attribute linkages in CTA and CN.     

A Three-Stage Expert System Based on Support Vector Machines for Thyroid Disease Diagnosis

In this paper, we present a three-stage expert system based on a hybrid support vector machines (SVM) approach to diagnose thyroid disease. Focusing on feature selection, the first stage aims at constructing diverse feature subsets with different discriminative capability. Switching from feature selection to model construction, in the second stage, the obtained feature subsets are fed into the designed SVM classifier for training an optimal predictor model whose parameters are optimized by particle swarm optimization (PSO). Finally, the obtained optimal SVM model proceeds to perform the thyroid disease diagnosis tasks using the most discriminative feature subset and the optimal parameters. The effectiveness of the proposed expert system (FS-PSO-SVM) has been rigorously evaluated against the thyroid disease dataset, which is commonly used among researchers who use machine learning methods for thyroid disease diagnosis. The proposed system has been compared with two other related methods including the SVM based on the Grid search technique (Grid-SVM) and the SVM based on Grid search and principle component analysis (PCA-Grid-SVM) in terms of their classification accuracy. Experimental results demonstrate that FS-PSO-SVM significantly outperforms the other ones. In addition, Compared to the existing methods in previous studies, the proposed system has achieved the highest classification accuracy reported so far by 10-fold cross-validation (CV) method, with the mean accuracy of 97.49% and with the maximum accuracy of 98.59%. Promisingly, the proposed FS-PSO-SVM expert system might serve as a new candidate of powerful tools for diagnosing thyroid disease with excellent performance.     

基于机器学习算法的重症缺血性脑卒中早期死亡预测效果评价

目的 评价支持向量机(SVM)、随机森林(RF)、极限梯度提升(XGBoost)3种机器学习算法与Logistic回归在重症缺血性脑卒中30天死亡结局的预测效果。方法 使用2008年至2019年MIMIC-IV数据库中符合纳排标准的2358例重症缺血性脑卒中患者资料,分别用SVM、随机森林、XGBoost3种机器学习算法与Logistic回归结合合成少数类过采样(SMOTE)技术建立早期死亡预测模型,并使用通过受试者工作特征曲线下面积(AUC)、准确度、F1-score、布里尔分数等指标评价预测效果。结果 SVM、随机森林、XGBoost与Logistic回归模型在原始类不平衡数据死亡预测中AUC值分别为0.78、0.81、0.84、0.83。应用SMOTE合成数据集后,SVM、随机森林、XGBoost与Logistic回归模型的AUC值分别为0.72、0.84、0.83、0.83。除SVM 外,机器学习算法与Logistic回归之间有相似的预测能力,但准确率、布里尔分数等优于Logistic回归,综合分类性能更优。结论 机器学习算法在重症缺血性脑卒中早期死亡预测中性能较传统方法更优,在解决重症患者预后预测研究问题中具有优势。     

一种基于2次核函数支持向量机的多步预测控制算法

提出了一种基于2次多项式核函数支持向量机的多步预测控制方法。通过黑箱辨识和线性化技术得到非线性系统的近似模型,根据预测控制机理,最小化滚动时域的二次型目标函数,利用模型算法控制的方法得到控制器的解析输出。通过一个标准预测模型和一个工业用连续搅拌槽式反应器的模型仿真验证了该控制器的性能,仿真结果表明:该控制器有着良好的预测性能。     

A Computer Aided Diagnosis System for Thyroid Disease Using Extreme Learning Machine

In this paper, we present an effective and efficient computer aided diagnosis (CAD) system based on principle component analysis (PCA) and extreme learning machine (ELM) to assist the task of thyroid disease diagnosis. The CAD system is comprised of three stages. Focusing on dimension reduction, the first stage applies PCA to construct the most discriminative new feature set. After then, the system switches to the second stage whose target is model construction. ELM classifier is explored to train an optimal predictive model whose parameters are optimized. As we known, the number of hidden neurons has an important role in the performance of ELM, so we propose an experimental method to hunt for the optimal value. Finally, the obtained optimal ELM model proceeds to perform the thyroid disease diagnosis tasks using the most discriminative new feature set and the optimal parameters. The effectiveness of the resultant CAD system (PCA-ELM) has been rigorously estimated on a thyroid disease dataset which is taken from UCI machine learning repository. We compare it with other related methods in terms of their classification accuracy. Experimental results demonstrate that PCA-ELM outperforms other ones reported so far by 10-fold cross-validation method, with the mean accuracy of 97.73% and with the maximum accuracy of 98.1%. Besides, PCA-ELM performs much faster than support vector machines (SVM) based CAD system. Consequently, the proposed method PCA-ELM can be considered as a new powerful tools for diagnosing thyroid disease with excellent performance and less time.