Computer Engineering and Applications ›› 2008, Vol. 44 ›› Issue (29): 61-64.DOI: 10.3778/j.issn.1002-8331.2008.29.016

• 理论研究 • Previous Articles     Next Articles

Tutorial of EM algorithm and its application:part Ⅰ

LI Chang-li,SHEN Yu-li   

  1. School of Information Engineering,Guangdong Ocean University,Zhanjiang,Guangdong 524088,China
  • Received:2007-11-20 Revised:2008-01-14 Online:2008-10-11 Published:2008-10-11
  • Contact: LI Chang-li

期望最大算法及其应用(1)

李昌利,沈玉利   

  1. 广东海洋大学 信息学院,广东 湛江 524088
  • 通讯作者: 李昌利

Abstract: EM algorithm is an effective method for maximum-likelihood estimate(MLE),which is mainly used to estimate parameters of incomplete data.On the one hand,by assuming the existence of hidden variable in EM algorithm,the likelihood function are greatly simplified;on the other hand,some special parameters estimation can be easily realized by virtue of EM algorithm.MLE is a common parameters estimation method and EM algorithm makes its application more extensive.This tutorial is organized from users’ points of view and its content is self-contained.

Key words: expectation-maximization(EM), maximum likelihood estimation(MLE), incomplete data, hidden variable

摘要: EM算法是实现极大似然估计的一种有效方法,主要用于非完全数据的参数估计。它通过假设隐变量的存在,极大地简化了似然方程;对于一些特殊的参数估计问题,利用EM算法也很容易实现。而极大似然估计是一种常用的参数估计方法,EM算法使其应用更加广泛。文章从应用者的角度出发,内容是自包含的。

关键词: 期望最大(EM), 极大似然估计(MLE), 不完全数据, 隐变量