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arXiv 2308.08079cs.LG
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用于稳定低维空间以支持地下不确定性量化与解释的刚性变换

Rigid Transformations for Stabilized Lower Dimensional Space to Support Subsurface Uncertainty Quantification and Interpretation

The University of Texas at Austin(德克萨斯大学奥斯汀分校)

Ademide O. Mabadeje, Michael J. Pyrcz

AI总结:

针对地下数据集降维中MDS解不稳定、无样本外扩展的问题,提出基于刚性变换的稳定低维表示方法,结合凸包算法等实现变换不变性与OOSP整合,经实验验证有效并提出应力比指标助力不确定性分析。

摘要:

地下数据集固有大数据特征,如体量庞大、特征多样、采样速度快,各类物理、工程与地质输入带来的维度灾难进一步加剧了这一问题。在现有降维(DR)方法中,非线性降维(NDR)方法,尤其是度量多维标度(Metric-multidimensional scaling, MDS),因地下数据集的固有复杂性而更受青睐。MDS虽能保留数据内在结构并量化不确定性,但其局限性包括:解不唯一且对欧氏变换具有不变性,同时缺乏样本外点(OOSP)扩展能力。为优化地下推断与机器学习工作流,必须将数据集转换为稳定的、可适配OOSP的低维表示。\n我们的方案采用刚性变换为低维空间(LDS)生成稳定的欧氏不变表示。通过计算MDS输入的相异度矩阵,并对多个实现施加刚性变换,我们确保了变换不变性并整合了OOSP。该过程利用凸包算法,结合损失函数与归一化应力进行失真量化。我们通过合成数据、不同距离度量以及Duvernay组的实际油井数据验证了该方法。结果证实,我们的方法可有效生成一致的LDS表示。此外,我们提出的“应力比”(SR)指标可揭示不确定性,有助于模型调整与推断分析。因此,该工作流有望提升地下能源资源工程及相关大数据工作流中非线性降维的可重复性与可比性。

英文摘要:

Subsurface datasets inherently possess big data characteristics such as vast volume, diverse features, and high sampling speeds, further compounded by the curse of dimensionality from various physical, engineering, and geological inputs. Among the existing dimensionality reduction (DR) methods, nonlinear dimensionality reduction (NDR) methods, especially Metric-multidimensional scaling (MDS), are preferred for subsurface datasets due to their inherent complexity. While MDS retains intrinsic data structure and quantifies uncertainty, its limitations include unstabilized unique solutions invariant to Euclidean transformations and an absence of out-of-sample points (OOSP) extension. To enhance subsurface inferential and machine learning workflows, datasets must be transformed into stable, reduced-dimension representations that accommodate OOSP. Our solution employs rigid transformations for a stabilized Euclidean invariant representation for LDS. By computing an MDS input dissimilarity matrix, and applying rigid transformations on multiple realizations, we ensure transformation invariance and integrate OOSP. This process leverages a convex hull algorithm and incorporates loss function and normalized stress for distortion quantification. We validate our approach with synthetic data, varying distance metrics, and real-world wells from the Duvernay Formation. Results confirm our method's efficacy in achieving consistent LDS representations. Furthermore, our proposed "stress ratio" (SR) metric provides insight into uncertainty, beneficial for model adjustments and inferential analysis. Consequently, our workflow promises enhanced repeatability and comparability in NDR for subsurface energy resource engineering and associated big data workflows.

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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