Elements of a theory of computer simulation - I: Sequential CA over random graphs
Elements of a theory of computer simulation - I: Sequential CA over random graphs
复制标题
DOI:
10.1016/s0096-3003(97)10166-7
复制
发表时间:
1999-02-01
影响因子:
4
通讯作者:
Reidys, CM
中科院分区:
文献类型:
--
作者:
Barrett, CL;Reidys, CM
This paper is a first step in the development of mathematical foundations for a theory of simulation. We employ sequentially updated cellular automata (sCA) over arbitrary graphs as a paradigmatic framework, In the development of the theory, we focus on the properties of causal dependencies among local mappings in a simulation. Let Y be a graph in which (a) each vertex i has a state x(i) is an element of {0,1} and (b) there exists a local map f(i) defined on the states of the Y-neighbors and x(i) that returns the state of y(i) is an element of {0, 1}. Suppose {i(l),..,, i(n)} is a permutation of the Y-vertices, then the order of application of the local maps fi, induces a sequential (or asynchronous) cellular automaton (sCA) over Y. In this paper we introduce a mapping between the base graph Y, over which the sCA is defined and which represents the mutual dependencies of the local maps, and the update graph U(Y), whose vertices are permutations of all Y-vertices. Two permutations nl, nz are adjacent in U(Y) if they differ in exactly two consecutive coordinates, {i(k), i(k+1)} and {i(k), i(k+1)} is not an element of eY. U(Y) represents a conceptual framework which allows to determine equivalence classes of sCA for a given graph X, independent of the family of local maps (f(i))(1 less than or equal to i less than or equal to n). We consider: (a) U as a random variable over G(n,p) and analyze the induced random graph U(G(n,p)), the update graph, and show (b) that U exhibits properties of a covariant functor. (C) 1999 Published by Elsevier Science Inc. All rights reserved.