论文标题
随机动力学系统的概率演变:一种中尺度的观点
Probabilistic Evolution of Stochastic Dynamical Systems: A Meso-scale Perspective
论文作者
论文摘要
随机动力学系统几乎在科学和工程的几乎所有领域都自然出现。通常,动态系统模型基于有关感兴趣的潜在动态的一些先验知识,在这种知识中,概率特征被用来量化与初始条件,外部激发等相关的不确定性。从概率建模常驻点,存在两种广泛的方法,即宏观尺度方法和微观尺度的方法。从经典上讲,诸如基于统计矩的策略之类的宏观尺度方法通常太粗糙,无法捕获非高斯分布的多模式形状或尾巴。另一方面,微尺度方法(例如基于随机样本的方法)在处理高维随机系统方面变得非常具有挑战性。鉴于这些潜在的局限性,这里提出了一种使用中级统计结构来描述概率角度的动力学演变。该统计结构的重要性是两倍。首先,可以针对任何任意随机空间量身定制。其次,它不仅保持样品轨迹周围的概率演变,而且比微尺度样品所需的中尺度组件更少。为了证明拟议的中尺度方案的功效,提供了一组复杂性的示例。提出了与基准随机模型作为保守模型的连接以及实际实施指南。
Stochastic dynamical systems arise naturally across nearly all areas of science and engineering. Typically, a dynamical system model is based on some prior knowledge about the underlying dynamics of interest in which probabilistic features are used to quantify and propagate uncertainties associated with the initial conditions, external excitations, etc. From a probabilistic modeling standing point, two broad classes of methods exist, i.e. macro-scale methods and micro-scale methods. Classically, macro-scale methods such as statistical moments-based strategies are usually too coarse to capture the multi-mode shape or tails of a non-Gaussian distribution. Micro-scale methods such as random samples-based approaches, on the other hand, become computationally very challenging in dealing with high-dimensional stochastic systems. In view of these potential limitations, a meso-scale scheme is proposed here that utilizes a meso-scale statistical structure to describe the dynamical evolution from a probabilistic perspective. The significance of this statistical structure is two-fold. First, it can be tailored to any arbitrary random space. Second, it not only maintains the probability evolution around sample trajectories but also requires fewer meso-scale components than the micro-scale samples. To demonstrate the efficacy of the proposed meso-scale scheme, a set of examples of increasing complexity are provided. Connections to the benchmark stochastic models as conservative and Markov models along with practical implementation guidelines are presented.