It means that $z$ has a (multivariate) normal distribution with 0 mean and identity covariance matrix. This essentially means each individual element of the vector $z$ has a standard normal distribution.
*AI, A Modern Approach," was given that title to break from previously narrow approaches to duplicating desirable qualities of human thinking.
Although Bayesian networks require somewhat resource intensive computational elements, the importance of Bayesian inference and probability are still of paramount importance in that some of the highest scientific ...
The chapters for Bayesian Networks are:
Naive Bayes, hidden variables, Markov
. Are We Going in the Right Direction? ... p.1049
If you find them interesting then invest more time to it. You might improve them and break new scientific ground.
Recent trend goes ...