数学理论与应用

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CTH算法,嵌入马氏链和RG-分解

Yiqiang Q. Zhao   

  1. School or Mathematics and Statistics, Carleton University, Ottawa, ON Canada K1S 5B6
  • 出版日期:2020-06-30 发布日期:2021-03-05

GTH Algorithm, Censored Markov Chains,and RG-Factorization

  • Online:2020-06-30 Published:2021-03-05

摘要: 本文是一篇关于GTH算法的综述。GTH算法是一种稳定的数值算法,常被用于计算马氏链的平 稳概率。GTH算法是高斯消元法的一种重排,因此它们在数学上具有等价的意义。GTH算法的所有步骤都 可以用嵌入的概念来进行概率解释,并且算法的每一次消元都会产生一个嵌入马氏链。在这种情况下,RG- 分解与高斯消元的中的LU-分解相对应。此外,在处理一个由无限多个线性方程组成的系统时,嵌入马氏链能被视为GTH算法的一种扩展,同时,它们被用于近似估算原始马氏链时,会产生在l1范数意义下的最小误差。

关键词: GTH算法;高斯消元法;马氏链, 嵌入马氏链;RG-分解, 平稳概率, 稳定的数值算法

Abstract:

In this paper, we provide a review on the GTH algorithm, which it a numerically stable algorithm for computing stationary probabilities of a Markov chain. Mathematically the GTH algorithm is an rearrangement of Gaussian elimination, and therefore they are mathematically equivalent. All components in the GTH algorithm can be interpreted probabilistically based on the censoring concept and each elimination in the GTH algorithm leads to a censored Markov chain. The RG-factorization is a counterpart t。the LU -decomposition for Gaussian elimination. The censored Markov chain can also be treated as an extended version of the GTH algorithm for a system consisting  of  infinitely many linear equations. The censored Markov chain produces a minimal error for approximating  the original chain under the l1norm.

Key words:

 GTH method, Gaussian elirnination, Markov chains , Censored Markov chains , RG-factorization, Stationary probabilities, Numericai stably algorithms