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arXiv 2203.12005stat.ME
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面向函数型数据的序贯贝叶斯配准方法

Sequential Bayesian Registration for Functional Data

Yoonji Kim, Oksana A. Chkrebtii, Sebastian A. Kurtek

AI总结:

针对函数型数据序贯采集、现有配准方法需全量重拟合的问题,提出基于序贯蒙特卡洛采样的贝叶斯序贯配准框架,可递归更新函数对齐并兼顾不确定性,结合分布式计算降低成本,在模拟与三类真实数据上验证了有效性。

摘要:

在诸多现代应用场景中,离散观测的数据可被自然地视为一组函数。函数型数据通常存在两类相互耦合的变异来源:幅值(y轴方向)与相位(x轴方向)。幅值与相位的提取过程被称为配准,这对于探索从环境监测到医学成像等诸多领域中函数型数据的底层结构至关重要。关键在于,这类数据往往是序贯采集的,新的函数观测值会随时间不断到达。尽管如此,现有的配准流程无法基于新数据序贯更新推断结果,需要重新拟合模型。为应对这些挑战,我们提出了一种用于函数型数据序贯配准的贝叶斯框架,该框架可在吸纳新的函数集合时更新统计推断结果。这种基于贝叶斯模型的序贯学习方法利用序贯蒙特卡洛采样递归更新观测函数的对齐结果,同时兼顾相关的不确定性。与使用马尔可夫链蒙特卡洛等迭代方法在全量数据上重新拟合模型相比,分布式计算显著降低了计算成本。模拟研究与对比实验表明,即便目标后验分布的结构具有挑战性,所提方法仍能表现良好。我们将所提方法应用于三个真实数据集:(1)加利福尼亚州韦卡亚河附近的年度干旱强度函数;(2)Null Island附近的年度海表盐度函数;(3)心电图信号中的一组重复模式序列。

英文摘要:

In many modern applications, discretely-observed data may be naturally understood as a set of functions. Functional data often exhibit two confounded sources of variability: amplitude (y-axis) and phase (x-axis). The extraction of amplitude and phase, a process known as registration, is essential in exploring the underlying structure of functional data in a variety of areas, from environmental monitoring to medical imaging. Critically, such data are often gathered sequentially with new functional observations arriving over time. Despite this, existing registration procedures do not sequentially update inference based on the new data, requiring model refitting. To address these challenges, we introduce a Bayesian framework for sequential registration of functional data, which updates statistical inference as new sets of functions are assimilated. This Bayesian model-based sequential learning approach utilizes sequential Monte Carlo sampling to recursively update the alignment of observed functions while accounting for associated uncertainty. Distributed computing significantly reduces computational cost relative to refitting the model using an iterative method such as Markov chain Monte Carlo on the full data. Simulation studies and comparisons reveal that the proposed approach performs well even when the target posterior distribution has a challenging structure. We apply the proposed method to three real datasets: (1) functions of annual drought intensity near Kaweah River in California, (2) annual sea surface salinity functions near Null Island, and (3) a sequence of repeated patterns in electrocardiogram signals.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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