not centrally-managed hierarchy
Properly defined, however, there can be self-organization without Emergence and emergence without self-organization. There is a link between them, but it's fairly subtle. See ch. 11 the dissertation.
Self-organization in action: some instances of Evolutionary Computation and Darwin Machines; qwerty; Cellular Automata (some of them), Dissipative Structure, and Pattern Formation in general; the so-called Edge Of Chaos. Nest Building by SocialInsects. Flock Ing.