arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2305.16622stat.COphysics.data-an
收藏

基于分层贝叶斯建模的逆向不确定性量化及其在核系统热工水力程序中的应用

Inverse Uncertainty Quantification by Hierarchical Bayesian Modeling and Application in Nuclear System Thermal-Hydraulics Codes

Chen Wang, Xu Wu, Tomasz Kozlowski

AI总结:

本文提出一种新颖的分层贝叶斯模型,有效缓解了核热工水力系统逆向不确定性量化中物理模型参数高变异性和过拟合问题,提供更优的后验分布估计并具备推广至大型数据库的潜力。

摘要:

逆向不确定性量化(IUQ)方法已被广泛用于量化核热工水力(TH)系统中物理模型参数(PMPs)的不确定性。本文提出了一种新颖的分层贝叶斯模型,旨在缓解IUQ中现有的两个挑战:实验条件变化下PMPs的高变异性,以及导致过拟合问题的未知模型偏差或异常值。使用TRACE程序和BFBT基准中的实测空泡份额数据,将所提出的分层模型与传统的单层贝叶斯模型进行了比较。采用哈密顿蒙特卡洛方法——无U型采样器(NUTS)进行后验采样。结果证明了所提出的分层模型在提供PMPs后验分布的更好估计方面具有有效性,并且不易发生过拟合。所提出的方法还展示了一种将IUQ推广到具有广泛实验条件范围的更大型数据库的有前景的途径。

英文摘要:

Inverse Uncertainty Quantification (IUQ) method has been widely used to quantify the uncertainty of Physical Model Parameters (PMPs) in nuclear Thermal Hydraulics (TH) systems. This paper introduces a novel hierarchical Bayesian model which aims to mitigate two existing challenges in IUQ: the high variability of PMPs under varying experimental conditions, and unknown model discrepancies or outliers causing over-fitting issues. The proposed hierarchical model is compared with the conventional single-level Bayesian model using TRACE code and the measured void fraction data in the BFBT benchmark. A Hamiltonian Monte Carlo Method - No U-Turn Sampler (NUTS) is used for posterior sampling. The results demonstrate the effectiveness of the proposed hierarchical model in providing better estimates of the posterior distributions of PMPs and being less prone to over-fitting. The proposed method also demonstrates a promising approach for generalizing IUQ to larger databases with broad ranges of experimental conditions.

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。

↑