论文标题

在存在观察相关的情况下,针对反问题的最佳实验设计

Optimal Experimental Design for Inverse Problems in the Presence of Observation Correlations

论文作者

Attia, Ahmed, Constantinescu, Emil

论文摘要

最佳实验设计(OED)是传感器放置的一般形式,也是有关工程或自然实验的数据收集策略的决策。在许多关键领域,例如电池设计,数值天气预测,地球科学以及环境和城市研究等许多关键领域,这种方法很普遍。但是,用于实验设计的最新计算方法不适应许多昂贵的X射线机器或雷达和卫星检索产生的观察误差的相关结构。丢弃明显的数据相关性会导致结果偏见,数据收集决策不良以及浪费宝贵的资源。我们提出了OED形式主义的一般表述,用于模型受限的大规模贝叶斯线性反问题,其中测量误差通常是相关的。所提出的方法利用矩阵的Hadamard产品来制定加权可能性,并且对有限和无限 - 维度贝叶斯逆问题有效。我们还讨论了广泛使用的方法,以放松二进制OED问题,鉴于提出的点加权方法,并清楚地解释了放松设计及其对观察误差协方差的影响。进行了广泛的数值实验,通过使用对流扩散模型对所提出的方法进行经验验证,在该模型中,目的是在有限的预算下最佳地放置一小组传感器,以预测污染物在有限域中的浓度。

Optimal experimental design (OED) is the general formalism of sensor placement and decisions about the data collection strategy for engineered or natural experiments. This approach is prevalent in many critical fields such as battery design, numerical weather prediction, geosciences, and environmental and urban studies. State-of-the-art computational methods for experimental design, however, do not accommodate correlation structure in observational errors produced by many expensive-to-operate devices such as X-ray machines or radar and satellite retrievals. Discarding evident data correlations leads to biased results, poor data collection decisions, and waste of valuable resources. We present a general formulation of the OED formalism for model-constrained large-scale Bayesian linear inverse problems, where measurement errors are generally correlated. The proposed approach utilizes the Hadamard product of matrices to formulate the weighted likelihood and is valid for both finite- and infinite- dimensional Bayesian inverse problems. We also discuss widely used approaches for relaxation of the binary OED problem, in light of the proposed pointwise weighting approach, and present a clear interpretation of the relaxed design and its effect on the observational error covariance. Extensive numerical experiments are carried out for empirical verification of the proposed approach by using an advection-diffusion model, where the objective is to optimally place a small set of sensors, under a limited budget, to predict the concentration of a contaminant in a bounded domain.

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