Wang Junshan, Jasra Ajay, De Iorio Maria
1 Department of Statistics and Applied Probability, National University of Singapore , Singapore, SG.
J Comput Biol. 2014 Feb;21(2):141-61. doi: 10.1089/cmb.2013.0082. Epub 2013 Oct 21.
In the following article, we provide an exposition of exact computational methods to perform parameter inference from partially observed network models. In particular, we consider the duplication attachment model that has a likelihood function that typically cannot be evaluated in any reasonable computational time. We consider a number of importance sampling (IS) and sequential Monte Carlo (SMC) methods for approximating the likelihood of the network model for a fixed parameter value. It is well-known that, for IS, the relative variance of the likelihood estimate typically grows at an exponential rate in the time parameter (here this is associated with the size of the network); we prove that, under assumptions, the SMC method will have relative variance that can grow only polynomially. In order to perform parameter estimation, we develop particle Markov chain Monte Carlo algorithms to perform Bayesian inference. Such algorithms use the aforementioned SMC algorithms within the transition dynamics. The approaches are illustrated numerically.
在以下文章中,我们阐述了从部分观测网络模型进行参数推断的精确计算方法。特别地,我们考虑了复制附着模型,其似然函数通常无法在任何合理的计算时间内进行评估。我们考虑了多种重要性抽样(IS)和序贯蒙特卡罗(SMC)方法,用于逼近固定参数值下网络模型的似然性。众所周知,对于IS而言,似然估计的相对方差通常会在时间参数(在此与网络规模相关)中呈指数速率增长;我们证明,在某些假设下,SMC方法的相对方差只会以多项式速率增长。为了进行参数估计,我们开发了粒子马尔可夫链蒙特卡罗算法来执行贝叶斯推断。此类算法在转移动态中使用上述SMC算法。通过数值示例对这些方法进行了说明。