75 research outputs found
Towards generalized measures grasping CA dynamics
In this paper we conceive Lyapunov exponents, measuring the rate of separation between two initially close configurations, and Jacobians, expressing the sensitivity of a CA's transition function to its inputs, for cellular automata (CA) based upon irregular tessellations of the n-dimensional Euclidean space. Further, we establish a relationship between both that enables us to derive a mean-field approximation of the upper bound of an irregular CA's maximum Lyapunov exponent. The soundness and usability of these measures is illustrated for a family of 2-state irregular totalistic CA
Localization dynamics in a binary two-dimensional cellular automaton: the Diffusion Rule
We study a two-dimensional cellular automaton (CA), called Diffusion Rule
(DR), which exhibits diffusion-like dynamics of propagating patterns. In
computational experiments we discover a wide range of mobile and stationary
localizations (gliders, oscillators, glider guns, puffer trains, etc), analyze
spatio-temporal dynamics of collisions between localizations, and discuss
possible applications in unconventional computing.Comment: Accepted to Journal of Cellular Automat
Pseudorandom number generator by cellular automata and its application to cryptography.
by Siu Chi Sang Obadiah.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 66-68).Abstracts in English and Chinese.Chapter 1 --- Pseudorandom Number Generator --- p.5Chapter 1.1 --- Introduction --- p.5Chapter 1.2 --- Statistical Indistingushible and Entropy --- p.7Chapter 1.3 --- Example of PNG --- p.9Chapter 2 --- Basic Knowledge of Cellular Automata --- p.12Chapter 2.1 --- Introduction --- p.12Chapter 2.2 --- Elementary and Totalistic Cellular Automata --- p.14Chapter 2.3 --- Four classes of Cellular Automata --- p.17Chapter 2.4 --- Entropy --- p.20Chapter 3 --- Theoretical analysis of the CA PNG --- p.26Chapter 3.1 --- The Generator --- p.26Chapter 3.2 --- Global Properties --- p.27Chapter 3.3 --- Stability Properties --- p.31Chapter 3.4 --- Particular Initial States --- p.33Chapter 3.5 --- Functional Properties --- p.38Chapter 3.6 --- Computational Theoretical Properties --- p.42Chapter 3.7 --- Finite Size Behaviour --- p.44Chapter 3.8 --- Statistical Properties --- p.51Chapter 3.8.1 --- statistical test used --- p.54Chapter 4 --- Practical Implementation of the CA PNG --- p.56Chapter 4.1 --- The implementation of the CA PNG --- p.56Chapter 4.2 --- Applied to the set of integers --- p.58Chapter 5 --- Application to Cryptography --- p.61Chapter 5.1 --- Stream Cipher --- p.61Chapter 5.2 --- One Time Pad --- p.62Chapter 5.3 --- Probabilistic Encryption --- p.63Chapter 5.4 --- Probabilistic Encryption with RSA --- p.64Chapter 5.5 --- Prove yourself --- p.65Bibliograph
On logical gates in precipitating medium: cellular automaton model
We study a two-dimensional semi-totalistic binary cell-state cellular
automaton, which imitates a reversible precipitation in an abstract chemical
medium. The systems exhibits a non-trivial growth and nucleation. We
demonstrate how basic computational operation can be realized in the system
when the propagation of the growing patterns is self-restricted by stationary
localizations. We show that precipitating patterns of different morphology
compete between each other and thus implement serial and non-serial logical
gates
A guided tour of asynchronous cellular automata
Research on asynchronous cellular automata has received a great amount of
attention these last years and has turned to a thriving field. We survey the
recent research that has been carried out on this topic and present a wide
state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat
Simulating city growth by using the cellular automata algorithm
The objective of this thesis is to develop and implement a Cellular Automata
(CA) algorithm to simulate urban growth process. It attempts to satisfy the
need to predict the future shape of a city, the way land uses sprawl in the
surroundings of that city and its population. Salonica city in Greece is
selected as a case study to simulate its urban growth. Cellular automaton
(CA) based models are increasingly used to investigate cities and urban
systems. Sprawling cities may be considered as complex adaptive systems,
and this warrants use of methodology that can accommodate the space-time
dynamics of many interacting entities. Automata tools are well-suited for
representation of such systems. By means of illustrating this point, the
development of a model for simulating the sprawl of land uses such as
commercial and residential and calculating the population who will reside in
the city is discussed
- …