论文标题
在匹配的过滤中以进行统计更改点检测
On Matched Filtering for Statistical Change Point Detection
论文作者
论文摘要
非参数和无分配的两样本测试是许多变化点检测算法的基础。但是,测试统计量随时间的函数中的随机性使它们容易受到误报和本地化的歧义。我们通过得出和应用与各种滑动窗口的更改的预期时间签名(在数据上的IID假设下的两样本测试)相匹配的过滤器来解决这些问题。这些过滤器渐近地相对于Wasserstein分位数测试的窗口大小,Wasserstein-1距离测试,最大平均差异平方(MMD^2)和Kolmogorov-Smirnov(KS)测试。匹配的过滤器显示具有两个重要属性。首先,它们是无分配的,因此可以在不知道基础数据分布的情况下应用。其次,它们是峰值的,它允许我们的方法产生的过滤信号保持预期的统计显着性。通过对合成数据以及活动识别基准测试的实验,我们证明了这种方法可以减轻假阳性并提高测试精度的实用性。我们的方法允许无需使用临时后处理即可删除当前方法常见的冗余检测,因此可以定位更改点。我们进一步强调了基于分位数量式(Q-Q)函数的统计测试的性能,并展示Q-Q函数对订单保留转换的不变性属性允许这些测试在同一数据集中具有单个阈值的不同尺度的更改点。
Non-parametric and distribution-free two-sample tests have been the foundation of many change point detection algorithms. However, randomness in the test statistic as a function of time makes them susceptible to false positives and localization ambiguity. We address these issues by deriving and applying filters matched to the expected temporal signatures of a change for various sliding window, two-sample tests under IID assumptions on the data. These filters are derived asymptotically with respect to the window size for the Wasserstein quantile test, the Wasserstein-1 distance test, Maximum Mean Discrepancy squared (MMD^2), and the Kolmogorov-Smirnov (KS) test. The matched filters are shown to have two important properties. First, they are distribution-free, and thus can be applied without prior knowledge of the underlying data distributions. Second, they are peak-preserving, which allows the filtered signal produced by our methods to maintain expected statistical significance. Through experiments on synthetic data as well as activity recognition benchmarks, we demonstrate the utility of this approach for mitigating false positives and improving the test precision. Our method allows for the localization of change points without the use of ad-hoc post-processing to remove redundant detections common to current methods. We further highlight the performance of statistical tests based on the Quantile-Quantile (Q-Q) function and show how the invariance property of the Q-Q function to order-preserving transformations allows these tests to detect change points of different scales with a single threshold within the same dataset.