Fig. 8

State diagram of sequential rejuvenation of a system with n=3 and k=1, under optimal (i.e., most effective) sequential attack. Each circle represents a set of n=3 nodes and their states: healthy (H), intruded (I) or rejuvenating (R). The types of transition are illustrated with arrows with different directions: rightward, when a previously healthy node transitions to intruded state; leftward, when a previously intruded node transitions to rejuvenating state; vertical (downward or upward), when a previously healthy node starts being rejuvenated