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基于轨迹点局部异常度的异常点检测算法 被引量:22
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作者 刘良旭 乐嘉锦 +1 位作者 乔少杰 宋加涛 《计算机学报》 EI CSCD 北大核心 2011年第10期1966-1975,共10页
随着大量的定位数据被收集在应用服务器,如何从大量定位轨迹数据挖掘异常信息已逐渐成为一个令人关注的研究课题.针对当前流行的、以轨迹片段表示局部特征的异常点检测算法存在的问题,文中提出了以轨迹点表示局部特征的异常点检测算法Tr... 随着大量的定位数据被收集在应用服务器,如何从大量定位轨迹数据挖掘异常信息已逐渐成为一个令人关注的研究课题.针对当前流行的、以轨迹片段表示局部特征的异常点检测算法存在的问题,文中提出了以轨迹点表示局部特征的异常点检测算法TraLOD.该算法不仅提出了将每个轨迹点赋予一个0~1的值来表示其局部异常程度,而且还引入了相对距离来计算轨迹片段之间的不匹配性.此外,针对数据挖掘算法效率低的缺点,TraLOD引入了R-Tree和距离特征矩阵来提高算法效率.性能分析和实验都证明了TraLOD的有效性. 展开更多
关键词 轨迹数据 异常点检测 局部异常度 距离特征矩阵 R树索引
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A novel shapelet transformation method for classification of multivariate time series with dynamic discriminative subsequence and application in anode current signals 被引量:3
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作者 WAN Xiao-xue CHEN Xiao-fang +2 位作者 GUI Wei-hua YUE Wei-chao XIE Yong-fang 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第1期114-131,共18页
Classification of multi-dimension time series(MTS) plays an important role in knowledge discovery of time series. Many methods for MTS classification have been presented. However, most of these methods did not conside... Classification of multi-dimension time series(MTS) plays an important role in knowledge discovery of time series. Many methods for MTS classification have been presented. However, most of these methods did not consider the kind of MTS whose discriminative subsequence was not restricted to one dimension and dynamic. In order to solve the above problem, a method to extract new features with extended shapelet transformation is proposed in this study. First, key features is extracted to replace k shapelets to calculate distance, which are extracted from candidate shapelets with one class for all dimensions. Second, feature of similarity numbers as a new feature is proposed to enhance the reliability of classification. Third, because of the time-consuming searching and clustering of shapelets, distance matrix is used to reduce the computing complexity. Experiments are carried out on public dataset and the results illustrate the effectiveness of the proposed method. Moreover, anode current signals(ACS) in the aluminum reduction cell are the aforementioned MTS, and the proposed method is successfully applied to the classification of ACS. 展开更多
关键词 anode current signals key features distance matrix feature of similarity numbers shapelet transformation
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