Search results for "explicit"

Modelling Aspects in Accumulative Roll Bonding process by Explicit Finite Element Analysis

2013

Accumulative Roll-Bonding (ARB) process is a severe plastic deformation (SPD) process, capable of developing grains below 1 μm in diameter and improving mechanical properties of the material. In this study, the authors compared two different FE-codes with respect of its applicability for numerical analysis of the ARB process. Modelling this process was achieved using the explicit code for Abaqus/CAE both in 2D and 3D. The proposed model was used to assess the impact of ARB cycles on the final material properties. The numerical results in 2D and 3D were compared and contrasted. The research work presented in this paper is focused on the simulation optimization based on CPU time minimization.…

Anodal Transcranial Direct Current Stimulation Over Prefrontal Cortex Slows Sequence Learning in Older Adults

2022

Aging is associated with declines in sensorimotor function. Several studies have demonstrated that transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation, can be combined with training to mitigate age-related cognitive and motor declines. However, in some cases, the application of tDCS disrupts performance and learning. Here, we applied anodal tDCS either over the left prefrontal cortex (PFC), right PFC, supplementary motor complex (SMC), the left M1, or in a sham condition while older adults (n = 63) practiced a Discrete Sequence Production (DSP), an explicit motor sequence, task across 3 days. We hypothesized that stimulation to either the right or left P…

Implicit–explicit schemes for nonlinear nonlocal equations with a gradient flow structure in one space dimension

2019

The positive effect of music on source memory

2015

Several studies have investigated how to improve episodic memory performance by manipulating the factors that are crucial for successful encoding. There is an ongoing debate about whether a complex stimulus such as music can improve memory, and in particular memory for words, rather than interfere with correct encoding of information. Therefore, the present study aims to investigate whether verbal episodic memory can be improved by background context of instrumental music. Twenty young adults were asked to memorize different lists of words presented against a background of music, environmental sounds or silence. Their episodic memory performance was then tested in terms of item and source …

La grammaire à l’école élémentaire française : un enseignement sous tension…

2022

La question de l’enseignement de la langue à l’école reste sensible en France et entraine régulièrement des débats et des controverses qui dépassent le cadre scolaire. La grammaire cristallise ces oppositions tant au niveau linguistique, didactique et pédagogique, politique, institutionnel, social… Nous sommes de fait face à un enseignement sous tension. Notre proposition tentera d’interroger et de croiser deux dimensions, les savoirs prescrits et les savoirs enseignés. Cette mise en interaction se fera selon deux axes: sur un axe diachronique, nous proposerons une analyse de quelques textes institutionnels qui se succèdent depuis vingt ans pour comprendre les attentes ministérielles dans u…

Pseudobosons, Riesz bases, and coherent states

2010

In a recent paper, Trifonov suggested a possible explicit model of a PT-symmetric system based on a modification of the canonical commutation relation. Although being rather intriguing, in his treatment many mathematical aspects of the model have just been neglected, making most of the results of that paper purely formal. For this reason we are re-considering the same model and we repeat and extend the same construction paying particular attention to all the subtle mathematical points. From our analysis the crucial role of Riesz bases clearly emerges. We also consider coherent states associated to the model.

Quelles différences entre enseignement explicite et modèle allostérique ?

2012

International audience

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…

Exact solution of generalized Tavis - Cummings models in quantum optics

1996

Quantum inverse methods are developed for the exact solution of models which describe N two-level atoms interacting with one mode of the quantized electromagnetic field containing an arbitrary number of excitations M. Either a Kerr-type nonlinearity or a Stark-shift term can be included in the model, and it is shown that these two cases can be mapped from one to the other. The method of solution provides a general framework within which many related problems can similarly be solved. Explicit formulae are given for the Rabi splitting of the models for some N and M, on- and off-resonance. It is also shown that the solution of the pure Tavis - Cummings model can be reduced to solving a homogen…

Explicit polynomial solutions of fourth order linear elliptic Partial Differential Equations for boundary based smooth surface generation

2011

We present an explicit polynomial solution method for surface generation. In this case the surface in question is characterized by some boundary configuration whereby the resulting surface conforms to a fourth order linear elliptic Partial Differential Equation, the Euler–Lagrange equation of a quadratic functional defined by a norm. In particular, the paper deals with surfaces generated as explicit Bézier polynomial solutions for the chosen Partial Differential Equation. To present the explicit solution methodologies adopted here we divide the Partial Differential Equations into two groups namely the orthogonal and the non-orthogonal cases. In order to demonstrate our methodology we discus…