Empirical Bayesian Analysis of Microarray (EBAM) is an empirical Bayes method originally developed for analysis of microarray gene expression data. Both the prior and posterior distributions are estimated from the data.
A gene is considered to be differentially expressed if its calculated posterior is larger than or equal to delta and no other genes with a more extreme test score that are not called differentially expressed. The suggested fudge factor a0 is chosen that leads to the largest number of differentially expressed genes. More information about empirical Bayes can be found (here), and detailed description on the EBAM algorithm be found from the original paper by Efron, B., Tibshirani, R. et al.