Nobili cellular automata (NCA) are a variation of von Neumann cellular automata (vNCA), in which additional states provide means of memory and the interference-free crossing of signal. Nobili cellular automata are the invention of Renato Nobili, a professor of physics at the University of Padova in Padova, Italy. Von Neumann specifically excluded the use of states dedicated to the crossing of signal.
The confluent state is altered, so that it acts as a signal crossing organ if exactly two signal paths are incident (they enter and leave the confluent state), or acts as a memory organ if only inputs exist.
The benefit of these alterations to the state set of von Neumann cellular automata is that signal crossing is greatly eased, configurations are slightly smaller than the corresponding configuration of von Neumann cellular automata, and the computational throughput is increased.
Read more about Nobili Cellular Automata: Signal Crossing in VNCA, Signal Crossing in NCA, Memory Storage in VNCA, Memory Storage in NCA