This paper addresses the multi-fault diagnosis problem of thrusters and sensors for autonomous underwater vehicles (AUVs). Traditional support vector domain description (SVDD) has low classification accuracy in the pr...This paper addresses the multi-fault diagnosis problem of thrusters and sensors for autonomous underwater vehicles (AUVs). Traditional support vector domain description (SVDD) has low classification accuracy in the process of AUV multi-fault pattern classification because of the effect of sample sparse density and the uneven distribution of samples, and so on. Thus, a fuzzy weighted support vector domain description (FWSVDD) method based on positive and negative class samples is proposed. In this method, the negative class sample is introduced during classifier training, and the local density and the class weight are introduced for each sample. To improve the multi-fault pattern classifier training speed and fault diagnosis accuracy of FWSVDD, a multi-fault mode classification method based on a hierarchical strategy is proposed. This method adds fault contain detection surface for each thruster and sensor to isolate fault components during fault diagnosis. By considering the problem of pattern classification for a fuzzy sample, which may be located in the overlapping area of hyper-spheres or may not belong to any hyper-sphere in the process of multi-fault classification based on FWSVDD, a relative distance judgment method is given. The effectiveness of the proposed multi-fault diagnosis approach is demonstrated through water tank experiments with an experimental AUV prototype.展开更多
To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a sm...To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a small subset of training data called support vectors. Namely, the number of training samples in the userdefined sphere is calculated and taken as the confidence measure, according to which the training samples are ranked in ascending order. Those former ranked ones are selected as the boundary targets for the SVDD training. Simulations on UCI data demonstrate the effectiveness and superiority of CSVDD： the number of training targets and the training time are reduced without any loss of accuracy.展开更多
利用常规方法检测网络数据流异常存在检测效率低的问题,为此提出基于改进支持向量数据描述(Support Vector Data Description,SVDD)算法的网络数据流异常检测方法。首先,选取一对一的构造方法将通信网络异常流量数据分为两个类别;其次,...利用常规方法检测网络数据流异常存在检测效率低的问题,为此提出基于改进支持向量数据描述(Support Vector Data Description,SVDD)算法的网络数据流异常检测方法。首先,选取一对一的构造方法将通信网络异常流量数据分为两个类别;其次,根据数据流的处理标准和需求,采用聚类分析技术构建监测模型;最后,通过改进SVDD流量异常检测模型对经过聚类特征提取的数据进行识别和检测。实验结果表明,该方法的检测准确率均高于97.5%,检测耗时较短,优于对照组。展开更多
在解决单分类问题的支持向量数据描述算法的基础上提出了适用于两类不平衡问题的I-SVDD(imbalance-support vector date description)算法.该算法通过增加样本的分布信息,对带野值的SVDD算法中的C值重新进行了定义.采用该算法对UC I数...在解决单分类问题的支持向量数据描述算法的基础上提出了适用于两类不平衡问题的I-SVDD(imbalance-support vector date description)算法.该算法通过增加样本的分布信息,对带野值的SVDD算法中的C值重新进行了定义.采用该算法对UC I数据集和人工样本集进行实验表明,改进后的I-SVDD算法比带野值的SVDD算法的AUC值平均提高12%以上;比AdaBoost算法在正类查全率上平均提高35%,精确度也提高了2%以上.I-SVDD算法在保证少数类样本高分类精度前提下,还有效提高了全样本的分类精度,更符合现实不平衡问题中对少数类样本的处理要求.展开更多
支持向量数据描述(support vector data description,SVDD)是一种具有单类数据描述能力的数据分类算法,因具有结构风险最小化的特性而受到广泛关注。SVDD的参数优化是影响其分类效果的关键问题,本文通过引入样本点的密度信息,提出了以...支持向量数据描述(support vector data description,SVDD)是一种具有单类数据描述能力的数据分类算法,因具有结构风险最小化的特性而受到广泛关注。SVDD的参数优化是影响其分类效果的关键问题,本文通过引入样本点的密度信息,提出了以界外密度最小化为目标的参数优化函数,避免了漏检率的计算问题,可充分利用训练数据的分布信息,提高数据描述能力,降低错分率。仿真实验和UCI标准数据库的对比验证表明,优化后的SVDD算法能够有效降低漏检率和错分率,提高算法性能。展开更多
支持向量数据描述(support vector data description,SVDD)常用于实现目标类样本充分、非目标类样本多样化的两类分类。在雷达目标识别应用中,SVDD分类性能随样本噪声增加迅速下降。为了解决这个问题,通过深入分析SVDD抗噪性能差的原因...支持向量数据描述(support vector data description,SVDD)常用于实现目标类样本充分、非目标类样本多样化的两类分类。在雷达目标识别应用中,SVDD分类性能随样本噪声增加迅速下降。为了解决这个问题,通过深入分析SVDD抗噪性能差的原因,提出了基于自适应SVDD的雷达目标分类方法。该方法利用接收机工作特性曲线建立信噪比与分类最优超球半径的关系模型,在目标分类过程中,针对不同信噪比自适应选择分类判决门限。仿真实验表明,相比于常规SVDD方法,自适应SVDD方法大大提高了低信噪比下目标分类性能。展开更多
One-class support vector machine （OCSVM） and support vector data description （SVDD） are two main domain-based one-class （kernel） classifiers. To reveal their relationship with density estimation in the case of t...One-class support vector machine （OCSVM） and support vector data description （SVDD） are two main domain-based one-class （kernel） classifiers. To reveal their relationship with density estimation in the case of the Gaussian kernel, OCSVM and SVDD are firstly unified into the framework of kernel density estimation, and the essential relationship between them is explicitly revealed. Then the result proves that the density estimation induced by OCSVM or SVDD is in agreement with the true density. Meanwhile, it can also reduce the integrated squared error （ISE）. Finally, experiments on several simulated datasets verify the revealed relationships.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51279040)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20112304110024)
文摘This paper addresses the multi-fault diagnosis problem of thrusters and sensors for autonomous underwater vehicles (AUVs). Traditional support vector domain description (SVDD) has low classification accuracy in the process of AUV multi-fault pattern classification because of the effect of sample sparse density and the uneven distribution of samples, and so on. Thus, a fuzzy weighted support vector domain description (FWSVDD) method based on positive and negative class samples is proposed. In this method, the negative class sample is introduced during classifier training, and the local density and the class weight are introduced for each sample. To improve the multi-fault pattern classifier training speed and fault diagnosis accuracy of FWSVDD, a multi-fault mode classification method based on a hierarchical strategy is proposed. This method adds fault contain detection surface for each thruster and sensor to isolate fault components during fault diagnosis. By considering the problem of pattern classification for a fuzzy sample, which may be located in the overlapping area of hyper-spheres or may not belong to any hyper-sphere in the process of multi-fault classification based on FWSVDD, a relative distance judgment method is given. The effectiveness of the proposed multi-fault diagnosis approach is demonstrated through water tank experiments with an experimental AUV prototype.
基金supported by the National Natural Science Foundation of China(6057407560674108).
文摘To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a small subset of training data called support vectors. Namely, the number of training samples in the userdefined sphere is calculated and taken as the confidence measure, according to which the training samples are ranked in ascending order. Those former ranked ones are selected as the boundary targets for the SVDD training. Simulations on UCI data demonstrate the effectiveness and superiority of CSVDD： the number of training targets and the training time are reduced without any loss of accuracy.
文摘利用常规方法检测网络数据流异常存在检测效率低的问题,为此提出基于改进支持向量数据描述(Support Vector Data Description,SVDD)算法的网络数据流异常检测方法。首先,选取一对一的构造方法将通信网络异常流量数据分为两个类别;其次,根据数据流的处理标准和需求,采用聚类分析技术构建监测模型;最后,通过改进SVDD流量异常检测模型对经过聚类特征提取的数据进行识别和检测。实验结果表明,该方法的检测准确率均高于97.5%,检测耗时较短,优于对照组。
文摘在解决单分类问题的支持向量数据描述算法的基础上提出了适用于两类不平衡问题的I-SVDD(imbalance-support vector date description)算法.该算法通过增加样本的分布信息,对带野值的SVDD算法中的C值重新进行了定义.采用该算法对UC I数据集和人工样本集进行实验表明,改进后的I-SVDD算法比带野值的SVDD算法的AUC值平均提高12%以上;比AdaBoost算法在正类查全率上平均提高35%,精确度也提高了2%以上.I-SVDD算法在保证少数类样本高分类精度前提下,还有效提高了全样本的分类精度,更符合现实不平衡问题中对少数类样本的处理要求.
文摘支持向量数据描述(support vector data description,SVDD)是一种具有单类数据描述能力的数据分类算法,因具有结构风险最小化的特性而受到广泛关注。SVDD的参数优化是影响其分类效果的关键问题,本文通过引入样本点的密度信息,提出了以界外密度最小化为目标的参数优化函数,避免了漏检率的计算问题,可充分利用训练数据的分布信息,提高数据描述能力,降低错分率。仿真实验和UCI标准数据库的对比验证表明,优化后的SVDD算法能够有效降低漏检率和错分率,提高算法性能。
文摘支持向量数据描述(support vector data description,SVDD)常用于实现目标类样本充分、非目标类样本多样化的两类分类。在雷达目标识别应用中,SVDD分类性能随样本噪声增加迅速下降。为了解决这个问题,通过深入分析SVDD抗噪性能差的原因,提出了基于自适应SVDD的雷达目标分类方法。该方法利用接收机工作特性曲线建立信噪比与分类最优超球半径的关系模型,在目标分类过程中,针对不同信噪比自适应选择分类判决门限。仿真实验表明,相比于常规SVDD方法,自适应SVDD方法大大提高了低信噪比下目标分类性能。
基金Supported by the National Natural Science Foundation of China(60603029)the Natural Science Foundation of Jiangsu Province(BK2007074)the Natural Science Foundation for Colleges and Universities in Jiangsu Province(06KJB520132)~~
文摘One-class support vector machine （OCSVM） and support vector data description （SVDD） are two main domain-based one-class （kernel） classifiers. To reveal their relationship with density estimation in the case of the Gaussian kernel, OCSVM and SVDD are firstly unified into the framework of kernel density estimation, and the essential relationship between them is explicitly revealed. Then the result proves that the density estimation induced by OCSVM or SVDD is in agreement with the true density. Meanwhile, it can also reduce the integrated squared error （ISE）. Finally, experiments on several simulated datasets verify the revealed relationships.
