Search results for "RCA"
showing 10 items of 3171 documents
CENTRAL LIMIT THEOREM FOR KERNEL ESTIMATOR OF INVARIANT DENSITY IN BIFURCATING MARKOV CHAINS MODELS
2021
Bifurcating Markov chains (BMC) are Markov chains indexed by a full binary tree representing the evolution of a trait along a population where each individual has two children. Motivated by the functional estimation of the density of the invariant probability measure which appears as the asymptotic distribution of the trait, we prove the consistence and the Gaussian fluctuations for a kernel estimator of this density based on late generations. In this setting, it is interesting to note that the distinction of the three regimes on the ergodic rate identified in a previous work (for fluctuations of average over large generations) disappears. This result is a first step to go beyond the thresh…
CENTRAL LIMIT THEOREM FOR BIFURCATING MARKOV CHAINS
2020
Bifurcating Markov chains (BMC) are Markov chains indexed by a full binary tree representing the evolution of a trait along a population where each individual has two children. We first provide a central limit theorem for general additive functionals of BMC, and prove the existence of three regimes. This corresponds to a competition between the reproducing rate (each individual has two children) and the ergodicity rate for the evolution of the trait. This is in contrast with the work of Guyon (2007), where the considered additive functionals are sums of martingale increments, and only one regime appears. Our first result can be seen as a discrete time version, but with general trait evoluti…
Intermittency in the homopolar disk-dynamo
2006
We study a modified Bullard dynamo and show that this system is equivalent to a nonlinear oscillator subject to a multiplicative noise. The stability analysis of this oscillator is performed. Two bifurcations are identified, first towards an \lq\lq intermittent\rq\rq state where the absorbing (non-dynamo) state is no more stable but the most probable value of the amplitude of the oscillator is still zero and secondly towards a \lq\lq turbulent\rq\rq (dynamo) state where it is possible to define unambiguously a (non-zero) most probable value around which the amplitude of the oscillator fluctuates. The bifurcation diagram of this system exhibits three regions which are analytically characteri…
Pulsating Dissipative Light Bullets
2009
Finding domains of existence for (3+1)D spatio-temporal dissipative solitons, also called “dissipative light bullets”, by direct numerical solving of a cubic-quintic Ginzburg-Landau equation (CGLE) is a lengthy procedure [1,2]. Variational approaches pave the way for quicker soliton solution mapping, as long as tractable trial functions remain suitable approximations for exact solutions [3,4].
Straw mulch as a sustainable solution to decrease runoff and erosion in glyphosate-treated clementine plantations in Eastern Spain. An assessment usi…
2019
[EN] In many Mediterranean areas, citrus orchards exhibit high soil loss rates because of the expansion of drip irrigation that allows cultivation on sloping terrain and the widespread use of glyphosate. To mitigate these non-sustainable soil losses, straw mulch could be applied as an efficient solution but this has been poorly studied. Therefore, the main goal of this paper was to assess the use of straw mulch as a tool to reduce soil losses in clementine plantations, which can be considered representative of a typical Mediterranean citrus orchard. A total of 40 rainfall simulation experiments were carried out on 20 pairs of neighbouring bare and mulched plots. Each experiment involved app…
Impact des rythmes circadiens sur l'exocytose des granules d'insuline
2015
Impact des rythmes circadiens sur l'exocytose des granules d'insuline. congrès de la société francophone du Diabète (SFD)
Electronic implementation of a non-linear oscillator subjected to noise : application to the modeling of neuronal information coding
2011
We study the nonlinear FitzHugh-Nagumo model witch describes the dynamics of excitable neural element. It is well known that this system exhibits three different possible responses. Indeed, the system can be mono-stable, oscillatory or bistable. In the oscillatory regime, the system periodically responds by generating action potential. By contrast, in the mono-stable state the system response remains constant after a transient. Under certain conditions, the system can undergo a bifurcation between the stable and the oscillatory regime via the so called Andronov-Hopf bifurcation. In this Phd thesis, we consider the FitzHugh-Nagumo model in the stable state, that is set near the Andronov-Hopf…
Comunicazione e divulgazione della ricerca scientifica applicata all’archeologia : il punto di vista degli young researchers
2017
International audience; What is the relationship between science and communication? And how important are cultural dissemination tools for the research survival? Recently, the archaeological study has undergone a substantial change, thanks to the introduction of non-invasive digital surveying techniques as well as physical and chemical analyses. It became therefore necessary to form a new archaeologist able to use them and to dialogue with new professional figures that move in the same direction. Also, it’s essential to promote the communication expert figures, which linked the scientific world and the public at large. Actually, Digital storytelling is a learning tool increasingly used by m…
La gestione delle acque nelle città fenicio-puniche della Sicilia: riflessioni e prospettive a partire dalle evidenze di Mozia, Solunto e Palermo
2017
The study of the hydraulic preparations of Phoenician-Punic Sicily constitutes a field of investigation alas problematic, especially with regard to the evidence related to the archaic-classical period. Not we know, for example, hydraulic works of a certain engineering commitment comparable to the oldest aqueducts of Tyre known from the sources 2 or the great Greek hydraulic infrastructures of the archaic era 3. The problem of water management in Sicily has, in recent years, received a considerable pulso and concerned especially the evidence of the Greek colonial foundation4 cities. Such "abundance" of data is not yet appreciable for Phoenician foundations, except, as we shall see, of Motya,…