
120 Cyber-Physical Systems: From Theory to Practice
quantity vector given the current one, or E(r[k +1]|r[k]). Specifically, we will view the stochastic
flow network as linear,ifE(r[k +1]|r[k]) is a purely linear function of r[k] for all k or equivalently
if E(r[k +1]|r[k]) = Q[k]r[k] for a fixed matrix Q[k] (which does not depend on r[k]) for each k.
Some remarks on linear stochastic flow networks are needed:
1. The condition for linearity does not require that the P[k] be independent of r[k], only that
the conditional mean of the next quantity vector is a linear function of the current one. One
example in Section 5.3.2 shows that even some dynamics ...