Search results for "diffusion model"
showing 10 items of 15 documents
La distribution des tuiles estampillées de la VIIIe légion Augusta autour de Mirebeau-sur-Bèze (Côte-d'Or, France)
2011
The 8th Augustan Legion was installed at Mirebeau-sur-Bèze (Côte-d'Or) after 70 AD following the troubles that arose with the Lingons. It remained there until the time of Domitian, a period of roughly twenty years, during which time the soldiers produced tiles stamped with the name of the legion. Analysis of the dispersion of the tiles in the region around Mirebeau shows that they followed the communication routes. Consideration of the contexts in which these tiles were used, their number on each site and the resources necessary to manufacture them reveals that the 8th Legion may have played a significant role in the diffusion and adoption of tiled roofs, a construction technique that was t…
Consistent device simulation model describing perovskite solar cells in steady-state, transient, and frequency domain
2019
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsami.9b04991
Diffusion modeling of COVID-19 under lockdown
2021
Viral immune evasion by sequence variation is a significant barrier to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine design and coronavirus disease-2019 diffusion under lockdown are unpredictable with subsequent waves. Our group has developed a computational model rooted in physics to address this challenge, aiming to predict the fitness landscape of SARS-CoV-2 diffusion using a variant of the bidimensional Ising model (2DIMV) connected seasonally. The 2DIMV works in a closed system composed of limited interaction subjects and conditioned by only temperature changes. Markov chain Monte Carlo method shows that an increase in temperature implicates reduced virus diffusi…
Social network analysis and political phenomena: a contribution to the small world theory
2014
An IMEX-Scheme for Pricing Options under Stochastic Volatility Models with Jumps
2014
Partial integro-differential equation (PIDE) formulations are often preferable for pricing options under models with stochastic volatility and jumps, especially for American-style option contracts. We consider the pricing of options under such models, namely the Bates model and the so-called stochastic volatility with contemporaneous jumps (SVCJ) model. The nonlocality of the jump terms in these models leads to matrices with full matrix blocks. Standard discretization methods are not viable directly since they would require the inversion of such a matrix. Instead, we adopt a two-step implicit-explicit (IMEX) time discretization scheme, the IMEX-CNAB scheme, where the jump term is treated ex…
On a Retarded Nonlocal Ordinary Differential System with Discrete Diffusion Modeling Life Tables
2021
In this paper, we consider a system of ordinary differential equations with non-local discrete diffusion and finite delay and with either a finite or an infinite number of equations. We prove several properties of solutions such as comparison, stability and symmetry. We create a numerical simulation showing that this model can be appropriate to model dynamical life tables in actuarial or demographic sciences. In this way, some indicators of goodness and smoothness are improved when comparing with classical techniques.
The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén
2012
Explosive volcanic eruptions of silicic magma often evolve towards non-explosive emissions of lava. The mechanisms underlying this transition remain unclear, however, a widely cited idea holds that shear-induced magma fragmentation plays a critical role by fostering volatile loss from fragmentary magma and through ash-filled cracks termed tuffisite. We test this hypothesis by measuring H2O concentrations within glassy tuffisite from the 2008–2011 rhyolitic eruption at volcan Chaiten, Chile. We show that while H2O concentrations decrease next to tuffisite veins and at the margins of obsidian fragments, the depletions cannot account for the disparity in H2O between explosively and effusively …
Prise en eau par composites carbone/époxy et leur effet sur le comportement mécanique : application aux réparations de structures en composite par co…
2013
Le travail présenté dans ce mémoire avait pour objectif d’étudier le processus de la pénétration d'eau dans les composites en carbone/époxyde dans un premier temps, et dans un deuxième temps, d’étudier l’effet de la prise en eau par ces matériaux sur les performances mécaniques des composites et leur joints collés. L'intégration de ces phénomènes physiques dans la modélisation numérique est d'une grande importance dans la prédiction de la durabilité d’une structure en composite subissant un vieillissement hygrothermique. Par conséquent, ce travail consiste non seulement en des observations expérimentales, mais aussi en des simulations numériques. Des corrélations entre les résultats obtenus…
Stability and Change in Diffusion Model Parameters over Two Years
2021
In recent years, mathematical models of decision making, such as the diffusion model, have been endorsed in individual differences research. These models can disentangle different components of the decision process, like processing speed, speed–accuracy trade-offs, and duration of non-decisional processes. The diffusion model estimates individual parameters of cognitive process components, thus allowing the study of individual differences. These parameters are often assumed to show trait-like properties, that is, within-person stability across tasks and time. However, the assumption of temporal stability has so far been insufficiently investigated. With this work, we explore stability and c…
On the Dissociation of Word/Nonword Repetition Effects in Lexical Decision: An Evidence Accumulation Account
2016
A number of models of visual-word recognition assume that the repetition of an item in a lexical decision experiment increases that item's familiarity/wordness. This would produce not only a facilitative repetition effect for words, but also an inhibitory effect for nonwords (i.e., more familiarity/wordness makes the negative decision slower). We conducted a two-block lexical decision experiment to examine word/nonword repetition effects in the framework of a leading “familiarity/wordness” model of the lexical decision task, namely, the diffusion model (Ratcliff et al., 2004). Results showed that while repeated words were responded to faster than the unrepeated words, repeated nonwords were…