Search results for "Simulation"
showing 10 items of 5095 documents
ELECTRON SPIN RELAXATION PROCESS IN SILICON CRYSTALS
2014
Recently, electrical injection of spin polarization in n-type and p-type silicon has been experimentally carried out up to room-temperature. Despite of these preliminary but promising experimental results, a comprehensive theoretical framework concerning the influence of transport conditions on the phonon-induced spin depolarization process in silicon structures, in a wide range of values of temperature, doping concentration and amplitude of external fields, is still in a developing stage. In order to elucidate the electron transport and spin dynamics of conduction electrons in lightly doped n-type Si crystals we have performed semiclassical multiparticle Monte Carlo simulations and numeric…
Monte Carlo Simulation of Spin Relaxation of Conduction Electrons in Silicon
2014
Recently, electrical injection of spin polarization in n-type and p-type silicon up to room-temperature has been experimental- ly carried out. Despite of these promising experimental results, a comprehensive theoretical framework concerning the influence of transport conditions on the spin depolarization process in silicon structures, in a wide range of values of temperature, doping concentration and amplitude of external fields, is still in a developing stage. In this contribution we use a semiclassical multiparti- cle Monte Carlo approach to simulate the electron transport and spin dynamics in lightly doped n-type Si crystals and numerically calculate the spin lifetimes of drifting electr…
HOT-ELECTRON NOISE FEATURES IN SILICON CRYSTALS OPERATING UNDER PERIODIC SIGNALS
2014
We study the intrinsic noise in n-type Si crystals operating under high-frequency periodic electric fields. To simulate the dy- namics of electrons in the bulk, by taking into account the main details of band structure, scattering processes, as well as heating effects, a Monte Carlo approach is used. The noise properties are investigated by computing the velocity fluctuations correlation function, its spectral density, and the total noise power for different values of the amplitude and frequency of the driving field. We show that the noise features are significantly affected by the electric field amplitude and frequency and discuss their peculiari- ties in comparison with those exhibited in…
Training machine learning models with synthetic data improves the prediction of ventricular origin in outflow tract ventricular arrhythmias
2022
In order to determine the site of origin (SOO) in outflow tract ventricular arrhythmias (OTVAs) before an ablation procedure, several algorithms based on manual identification of electrocardiogram (ECG) features, have been developed. However, the reported accuracy decreases when tested with different datasets. Machine learning algorithms can automatize the process and improve generalization, but their performance is hampered by the lack of large enough OTVA databases. We propose the use of detailed electrophysiological simulations of OTVAs to train a machine learning classification model to predict the ventricular origin of the SOO of ectopic beats. We generated a synthetic database of 12-l…
Prospectives to tractor cabin design with computational acoustics tools
2011
Computational acoustical models allow automated optimization of tractor design with respect to acoustic properties, which could speed up significantly the design process of tractor cabin prototypes. This article gives insightful prospectives to the tractor design process by considering modern computational acoustics technology. Mathematical formulation for a system consisting of vibrating elastic tractor structure and airfilled acoustic enclosure are given and a related numerical solution technique with finite element method (FEM) is presented. Simulation results produced with commercially available software are reviewed. nonPeerReviewed
Optimal control in models with conductive‐radiative heat transfer
2003
In this paper an optimal control problem for the elliptic boundary value problem with nonlocal boundary conditions is considered. It is shown that the weak solutions of the boundary value problem depend smoothly on the control parameter and that the cost functional of the optimal control problem is Frechet differentiable with respect to the control parameter. Optimalus valdymas modeliuose su laidžiu-radioaktyviu šilumos pernešimu Santrauka Darbe nagrinejamas nelokalaus kraštinio uždavinio optimalaus valdymo uždavinys. Parodyta, kad silpnasis kraštinio uždavinio sprendinys tolydžiai priklauso nuo valdomojo parametro, taigi, optimalaus valdymo tikslo funkcija yra diferencijuojama Freše prasme…
Pensiero, percezione e linguaggio in W.V. Quine
2012
Notwithstanding his well known behaviorism, Quine connects language learning to the ability of understanding others by means of empathy, namely perceiving what an other is perceiving. The paper discusses and resolves the prima facie oddity between this thesis and Quine's criticism of propositional attitudes. It analyzes the notion of empathy and the cognitive mechanism underlying it. It explains also the role of empathy and of mindreading abilities in language learning and understanding others. Comparing Quine's account of mindreading to the main options in the current debate on the topic, it assess the validity of the Quinean inspired blend of rationality-based and hybrid view-based strate…
A Simplified LCA Tool for Solar Heating and Cooling Systems
2016
Abstract This paper presents a user-friendly Life Cycle Assessment tool, which aims to support researchers, designers and decision-makers in evaluating the life cycle energy and environmental advantages related to the use of solar heating and cooling (SHC) systems in substitution of conventional ones, considering specific climatic conditions and building loads. The tool was developed within the Task 48 “Quality Assurance & Support Measures for Solar Cooling Systems”, promoted by the International Energy Agency in the framework of the SHC Programme.
Fondements et approches de modélisation 3D des environnements urbains pour la géosimulation
2015
National audience; Dans le prolongement de la théorie de la géographie virtuelle proposée par Mi¬chael Batty (1997, 2008), les Environne¬ments Géographiques Virtuels (EGVs) sont proposés comme une nouvelle génération d’outils d’analyses géographiques, d’amé¬nagements et de prospective de façon plus approfondie (Lin et al., 2012). Le déve¬loppement des EGVs répond aux trois exigences scientifiques fondamentales des sciences de l’information géographique : vi-sualisation multidimensionnelle, simulation dynamique de phénomènes géographiques et la participation collaborative pluridisci¬plinaire (Goodchild, 2009). A ce titre, les Environnements Virtuels Urbains pour la Géosimulation (EVUG) sont …
Ergonomic Comparison of a Sit-Stand Workstation With a Traditional Workstation in Visual Display Unit Work
2013
Purpose: To compare ergonomics of an electrically adjustable sit-stand workstation with a traditional workstation in video display unit (VDU) work. Methods: Twelve female workers (aged 27-53 years) participated in this experimental study. Electromyography, wrist postures, subjective assessments, and productivity were used to make the ergonomic comparison. Results: The muscle activity of the right trapezius (p=0.01) and left wrist extensors (p=0.02), extension of the right (p=0.05) and left (p=0.002) wrist, and perceived strain of the arms (p=0.05) were lower and productivity was better (p=0.02) when the workers used a low-sitting, high-sitting, or standing posture at the sit-stand workstati…