42 research outputs found
All binary number-conserving cellular automata based on adjacent cells are intrinsically one-dimensional
A binary number-conserving cellular automaton is a discrete dynamical system that models the movement of particles in a d-dimensional grid. Each cell of the grid is either empty or contains a particle. In subsequent time steps the particles move between the cells, but in one cell there can be at most one particle at a time. In this paper, the von Neumann neighborhood is considered, which means that in each time step a particle can move to an adjacent cell only. It is proven that regardless of the dimension d, all of these cellular automata are trivial, as they are intrinsically one-dimensional. Thus, for given d, there are only 4d+1 binary number-conserving cellular automata with the von Neumann neighborhood: the identity rule and the shift and traffic rules in each of the 2d possible directions
Number-conserving cellular automata with a von Neumann neighborhood of range one
We present necessary and sufficient conditions for a cellular automaton with
a von Neumann neighborhood of range one to be number-conserving. The conditions
are formulated for any dimension and for any set of states containing zero. The
use of the geometric structure of the von Neumann neighborhood allows for
computationally tractable conditions even in higher dimensions.Comment: 15 pages, 3 figure
A split-and-perturb decomposition of number-conserving cellular automata
This paper concerns -dimensional cellular automata with the von Neumann
neighborhood that conserve the sum of the states of all their cells. These
automata, called number-conserving or density-conserving cellular automata, are
of particular interest to mathematicians, computer scientists and physicists,
as they can serve as models of physical phenomena obeying some conservation
law. We propose a new approach to study such cellular automata that works in
any dimension and for any set of states . Essentially, the local rule of
a cellular automaton is decomposed into two parts: a split function and a
perturbation. This decomposition is unique and, moreover, the set of all
possible split functions has a very simple structure, while the set of all
perturbations forms a linear space and is therefore very easy to describe in
terms of its basis. We show how this approach allows to find all
number-conserving cellular automata in many cases of and . In
particular, we find all three-dimensional number-conserving CAs with three
states, which until now was beyond the capabilities of computers
A statistical approach to the identification of diploid cellular automata based on incomplete observations
In this paper, the identification problem of diploid cellular automata is considered, in which, based on a series of incomplete observations, the underlying cellular automaton rules and the states of missing cell states are to be uncovered. An algorithm for identifying the rule, based on a statistical parameter estimation method using a normal distribution approximation, is presented. In addition, an algorithm for filling the missing cell states is formulated. The accuracy of these methods is examined in a series of computational experiments