关于因子图和消息传递算法领域的非常经典的论文，绝对值得大家仔细阅读-A large variety of algorithms in coding, signal processing,

and artificial intelligence may be viewed as instances of

the summary-product algorithm (or belief/probability

propagation algorithm), which operates by message

passing in a graphical model. Specific instances of such algorithms

include Kalman filtering and smoothing　the forward–backward

algorithm for hidden Markov models