Uncertainty analysis in the outcomes of model predictions is a key element in decision-based material design to establish confidence in the models and evaluate the fidelity of models. Uncertainty Propagation (UP) is a technique to determine model output uncertainties based on the uncertainty in its input variables. The most common and simplest approach to propagate the uncertainty from a model inputs to its outputs is by feeding a large number of samples to the model, known as Monte Carlo (MC) simulation which requires exhaustive sampling from the input variable distributions. However, MC simulations are impractical when models are computationally expensive. In this work, we investigate the hypothesis that while all samples are useful on average, some samples must be more useful than others. Thus, reordering MC samples and propagating more useful samples can lead to enhanced convergence in statistics of interest earlier and thus, reducing the computational burden of UP process. Here, we introduce a methodology to adaptively reorder MC samples and show how it results in reduction of computational expense of UP processes.
翻译:模型预测结果的不确定性分析是以决定为基础的材料设计中的一个关键要素,以建立对模型的信心并评价模型的忠诚性。不确定性的传播(UP)是一种根据输入变量的不确定性确定模型产出不确定性的技术。传播模型投入结果的不确定性的最常见和最简单的方法是将大量样本(称为蒙特卡洛(Monte Carlo)(MC)模拟)注入模型,该模型需要从输入变量分布中进行详尽的抽样。然而,当模型计算费用昂贵时,MC模拟是不切实际的。在这项工作中,我们调查的假设是,虽然所有样本平均都有用,但有些样本必须比其他样本有用。因此,重新订购MC样品和扩散更有用的样品可以促进早期利益统计的趋同,从而减少UP过程的计算负担。在这里,我们引入了一种适应性重新订购MC样品的方法,并表明它如何减少UP过程的计算费用。