An Experimental Study of Robustness to Asynchronism for Elementary Cellular Automata

Cellular Automata (CA) are a class of discrete dynamical systems that have been widely used to model complex systems in which the dynamics is specified at local cell-scale. Classically, CA are run on a regular lattice and with perfect synchronicity. However, these two assumptions have little chance to truthfully represent what happens at the microscopic scale for physical, biological or social systems. One may thus wonder whether CA do keep their behavior when submitted to small perturbations of synchronicity. This work focuses on the study of one-dimensional (1D) asynchronous CA with two states and nearest-neighbors. We define what we mean by ``the behavior of CA is robust to asynchronism'' using a statistical approach with macroscopic parameters. and we present an experimental protocol aimed at finding which are the robust 1D elementary CA. To conclude, we examine how the results exposed can be used as a guideline for the research of suitable models according to robustness criteria.Comment: Version : Feb 13th, 2004, submitted to Complex System

Protein expression and genetic variability of canine Can f 1 in golden and Labrador retriever service dogs.

BackgroundValued for trainability in diverse tasks, dogs are the primary service animal used to assist individuals with disabilities. Despite their utility, many people in need of service dogs are sensitive to the primary dog allergen, Can f 1, encoded by the Lipocalin 1 gene (LCN1). Several organizations specifically breed service dogs to meet special needs and would like to reduce allergenic potential if possible. In this study, we evaluated the expression of Can f 1 protein and the inherent variability of LCN1 in two breeds used extensively as service dogs. Saliva samples from equal numbers of male and female Labrador retrievers (n = 12), golden retrievers (n = 12), and Labrador-golden crosses (n = 12) were collected 1 h after the morning meal. Can f 1 protein concentrations in the saliva were measured by ELISA, and the LCN1 5' and 3' UTRs and exons sequenced.ResultsThere was no sex effect (p > 0.2) nor time-of-day effect; however, Can f 1 protein levels varied by breed with Labrador retrievers being lower than golden retrievers (3.18 ± 0.51 and 5.35 ± 0.52 μg/ml, respectively, p < 0.0075), and the Labrador-golden crosses having intermediate levels (3.77 ± 0.48 μg/ml). Although several novel SNPs were identified in LCN1, there were no significant breed-specific sequence differences in the gene and no association of LCN1 genotypes with Can f 1 expression.ConclusionsAs service dogs, Labrador retrievers likely have lower allergenic potential and, though there were no DNA sequence differences identified, classical genetic selection on the estimated breeding values associated with salivary Can f 1 expression may further reduce that potential

Jeux et enjeux olympiques

Les actes de candidatures et de choix des villes pour l'organisation des différentes sessions des Jeux Olympiques contemporains ne sont pas le fruit du hasard. Dans l'un et l'autre cas, il s'agit d'actes dont la signification s'inscrit dans le contexte politique du moment

Modelling the Quantum Capacitance of Single-layer and Bilayer Graphene

In this paper, we report the modelling of quantum capacitance in both single-layer and bilayer graphene devices to investigate the temperature dependence. The model includes the existence of electron and hole puddles due to local fluctuations of the potential, which is taken into account with the possibility of finite lifetimes of electronic states to calculate the quantum capacitance using the Gaussian distribution. The results indicate that the simulations are in agreement with the experimental measurements, which proves the accuracy of the proposed model. On the other hand, temperature dependence around the charge neutrality point has been reported for both single and bilayer graphene

Intrinsic Simulations between Stochastic Cellular Automata

The paper proposes a simple formalism for dealing with deterministic, non-deterministic and stochastic cellular automata in a unifying and composable manner. Armed with this formalism, we extend the notion of intrinsic simulation between deterministic cellular automata, to the non-deterministic and stochastic settings. We then provide explicit tools to prove or disprove the existence of such a simulation between two stochastic cellular automata, even though the intrinsic simulation relation is shown to be undecidable in dimension two and higher. The key result behind this is the caracterization of equality of stochastic global maps by the existence of a coupling between the random sources. We then prove that there is a universal non-deterministic cellular automaton, but no universal stochastic cellular automaton. Yet we provide stochastic cellular automata achieving optimal partial universality.Comment: In Proceedings AUTOMATA&JAC 2012, arXiv:1208.249

La question du corps dans la politique sportive de l'Algérie

Fates Youcef. La question du corps dans la politique sportive de l'Algérie. In: Cahiers de la Méditerranée, n°32, 1, 1986. Les Maghrébins et la culture du corps, sous la direction de Borhane Erraïs et Mohamed Ben Larbi. pp. 79-89

Jeux et enjeux olympiques

Candidatures and choice of the towns which organise the different sessions of the contemporary Olympic games is not made at random. In both cases it is in close relation with the current political context.Les actes de candidatures et de choix des villes pour l'organisation des différentes sessions des Jeux Olympiques contemporains ne sont pas le fruit du hasard. Dans l'un et l'autre cas, il s'agit d'actes dont la signification s'inscrit dans le contexte politique du moment.Las candidaturas y la elección de las ciudades organizadoras de los Juegos Olímpicos contemporáneos no son fruto del azar sino actos cuya significacion encaja con el contexto político del momento.Leblanc Pierre, Fates Youcef. Jeux et enjeux olympiques. In: Mappemonde, 1989/2. pp. 19-21

Robustesse de la dynamique des systèmes discrets (le cas de l'asynchronisme dans les automates cellulaires)

L'objet de ce travail est d'étudier ce qui se produit lorsque l'on perturbe la dynamique d'un automate cellulaire (par exemple en n'effectuant plus toutes les transitions de façon synchrone). Notre motivation est de parvenir à donner un cadre formel qui puisse décrire la notion informelle de robustesse'' : on constate que certains automates cellulaires gardent le même type de comportement'' lorsqu'ils sont perturbés alors que d'autres automates changent leur comportement soit de façon continue, soit de façon brutale'' (on parle alors de transition de phase). La question principale consiste donc à quantifier les phénomènes observés en utilisant les mesures appropriées. Nous proposons une méthode de classification des automates cellulaires qui utilise les variations statistiques du paramètre densité. Partant de ces premiers résultats, nous étudions la notion de robustesse à l'asynchronisme selon un protocole expérimental similaire. Ces études permettent de effectivement de classer les automates en des classes distinctes ; certaines d'entre elles sont en partie étudiées analytiquement à l'aide de modèles probabilistes (martingales et chaines de Markov) qui permettent d'estimer les temps de convergence vers un point fixe. D'autres automates sont étudiés expérimentalement : nous montrons en particulier l'existence de transitions de phase appartenant à la classe d'universalité de la percolation dirigée et nous examinons la robustesse du Jeu de la Vie à la lumière de modifications de topologie.The aim of this work is to study what happens when the dynamics of a cellular automaton is perturbed (for example when the transitions are not all made at each time step). We give a formal framework to the informal concept of robusteness'' in order to explain why some cellular automata keep their behaviour constant while others change their behaviour, either in a continuous way, or with phase transitions''. The main question thus consists in quantifying the phenomena using appropriate measures. We propose a method of classification of cellular automata that use the statistical variations of the density parameter. Starting from these results, the robustnes of various automata is estimated experimentally. Results show that the celular automata studided can indeed be partionned in to various classes. Some of these classes are then studied analytically with probabilistic models such as martingales and Markov chains. Other automata are studied experimentally : we give evidence that some of the transition phases belong to the universality class and we study how the robustness of the Game of Life evolves with topology perturbations.LYON-ENS Sciences (693872304) / SudocNANCY-INRIA Lorraine LORIA (545472304) / SudocSudocFranceF

A corps perdu... ou des activités corporelles à caractère ludique des femmes travailleuses (région d'Alger)

Lalami -Fates Fériel. A corps perdu... ou des activités corporelles à caractère ludique des femmes travailleuses (région d'Alger). In: Cahiers de la Méditerranée, n°32, 1, 1986. Les Maghrébins et la culture du corps, sous la direction de Borhane Erraïs et Mohamed Ben Larbi. pp. 91-103