天文学中周期时间序列的核方法Kernels for Periodic Time Series Arising in Astronomy |
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课程网址: | http://videolectures.net/ecmlpkdd09_wachman_kptsaa/ |
主讲教师: | Gabriel Wachman |
开课单位: | 塔夫斯大学 |
开课时间: | 2009-10-20 |
课程语种: | 英语 |
中文简介: | 我们提出了一种方法,使用星亮度的时间序列将机器学习算法应用于天文星测量的自动分类。目前,这种分类需要大量的域专家时间。我们表明,从时间序列中提取的相位不变相似性和显式特征的组合提供了领域专家级别分类。为了促进这种应用,我们研究了互相关作为时间序列的一般相位不变相似函数。我们建立了几个互相关的理论性质,表明它具有直观的吸引力和算法易处理性,但不是半正的,因此通常不适用于核方法。作为一种解决方案,我们引入了具有与互相关相同的直观吸引力的半正定相似度函数。天文学领域以及其他几个数据集的实验评估证明了内核的性能和相关的相似性函数。 |
课程简介: | We present a method for applying machine learning algorithms to the automatic classification of astronomy star surveys using time series of star brightness. Currently such classification requires a large amount of domain expert time. We show that a combination of phase invariant similarity and explicit features extracted from the time series provide domain expert level classification. To facilitate this application, we investigate the cross-correlation as a general phase invariant similarity function for time series. We establish several theoretical properties of cross-correlation showing that it is intuitively appealing and algorithmically tractable, but not positive semidefinite, and therefore not generally applicable with kernel methods. As a solution we introduce a positive semidefinite similarity function with the same intuitive appeal as cross-correlation. An experimental evaluation in the astronomy domain as well as several other data sets demonstrates the performance of the kernel and related similarity functions. |
关 键 词: | 星亮度; 天文星测量; 机器学习算法 |
课程来源: | 视频讲座网 |
最后编审: | 2019-03-27:lxf |
阅读次数: | 53 |