(元胞自动机).ppt

Cellular Automata and Cellular Automata and Artificial Life Artificial Life Cellular Automata Cellular Automata ( (元胞自动机元胞自动机) ) ? Each Unit Is an Automata ? Connectivity: Each Automata Is Linked With Its Neighborhood An example of Cellular An example of Cellular Automata Automata ? every unit has a value: a, b, c and d. a bcd bc An example of Cellular Automata An example of Cellular Automata ? Rule 90 1 000 0001011010 outputs 000 001 010 011 100 101 110 111 Input States An example of Cellular Automata An example of Cellular Automata ? There are 2^3=8 different input states. ? There are 2^8 =256 different state change rules. ? Each rule is numbered from 0 to 255. 01011010 outputs 000 001 010 011 100 101 110 111 Input States An example of Cellular Automata An example of Cellular Automata ? See the pictures of the dynamics of these rules. ? Text book: Gerard Weisbuch , Complex Systems Dynamics, an introduction to automata networks, Addison-Wesley Publishing Company, Inc. USA. P25-P27 Strong attractors Strong attractors ? Rule 250: all 1 ? Rule 128: all configurations with at least one 0 converge toward the attractor containing only 0 ’ s, ( exception of configuration of all 1 ’ s ) Short-period attractors Short-period attractors ? Rule 108 and 178: periods of 1 or 2. long-period attractors long-period attractors ? Rule 90 and 126: too long to be easily observable. One dimensional cellular One dimensional cellular automata with three inputs automata with three inputs ? One dimension ( two dimensions ) ? With three inputs ( with more than 3 inputs) ? Neighbors: 3, 5, … The nearest neighbors