Search results for "imulation"
showing 10 items of 7271 documents
150 years of rowing faster: what are the sources of more and more speed?
2015
Rowing has a 150 yr+ competitive history. Examining results from historic races like Oxford-Cambridge (established 1829) and the world championships (established 1893) reveals a linear increase in boat speed by 2-3% per decade. Boat velocity increases if propulsive power is increased and/or power losses are reduced. Over time, the propulsive power capacity of elite rowers has increased. Part of this increase is a result of recruiting athletes from a population that has become taller (1-3 cm per decade) and heavier. Modern world class rowers are typically 190-200 cm tall and weigh 90-100 kg. However, physical capacity does not scale directly with body dimensions but conforms instead to biolo…
A distributed visualization system for crowd simulations1
2011
The visualization system of large-scale crowd simulations should scale up with both the number of visuals views of the virtual world and the number of agents displayed in each visual. Otherwise, we could have large scale crowd simulations where only a small percentage of the population is displayed. Several approaches have been proposed in order to efficiently render crowds of animated characters. However, these approaches either render crowds animated with simple behaviors or they can only support a few hundreds of user-driven entities. In this paper, we propose a distributed visualization system for large crowds of autonomous agents that allows the visualization of crowds animated with co…
ON THE EXISTENCE OF LIMIT CYCLES IN OPINION FORMATION PROCESSES UNDER TIME PERIODIC INFLUENCE OF PERSUADERS
2008
This paper concerns a model of opinion formation in a population of interacting individuals under the influence of external leaders or persuaders, which act in a time periodic fashion. The model is formulated within a general framework inspired to a discrete generalized kinetic approach, which has been developed in Ref. 6. It is expressed by a system of non-autonomous nonlinear ordinary differential equations. The dynamics of such a system is investigated and the existence of a globally asymptotically stable periodic solution is analytically proved in three example cases, each one corresponding to a different quantitative choice of the actions of the persuaders. Equivalently, in three part…
Distortion product otoacoustic emissions in healthy newborns: normative data.
1995
Distortion product otoacoustic emissions (DPOAE) offer an alternative to transiently evoked otoacoustic emissions (TEOAE) as an audiological test. The former can be used as a screening technique, and may also provide frequency-specific information about the functional state of the cochlea. We recorded DPOAE in a group of healthy newborns to establish the Characteristics of a DPOAE “audiogram” (DP-gram) in this population. The DP-gram can be obtained with characteristics quite similar to those observed in adults, with two sharp peaks of maximum amplitude at F2 frequencies of 2 kHz and 5-6 kHz, and a decline in DPOAE amplitude in mid frequencies. The results confirm the limitations of DPOAE r…
Mathematical modelling of social obesity epidemic in the region of Valencia, Spain
2010
In this article, we analyse the incidence of excess weight in 24- to 65-year-old residents in the region of Valencia, Spain, and predict its behaviour in the coming years. In addition, we present some possible strategies to prevent the spread of the obesity epidemic. We use classical logistic regression analysis to find out that a sedentary lifestyle and unhealthy nutritional habits are the most important causes of obesity in the 24- to 65-year-old population in Valencia. We propose a new mathematical model of epidemiological type to predict the incidence of excess weight in this population in the coming years. Based on the mathematical model sensitivity analysis, some possible general stra…
Il Protocollo RE4BES per il potenziamento delle abilità cognitive, emotive e sociali di un bambino con disturbo dello spettro autistico
2020
The study reports an intervention study on a child with Autism Spectrum Disorder. The intervention was conducted using some activities included in the RE4BES protocol, a collection of guidelines for the implementation of educational robots intervention for children and young people with special educational eeeds. To assess the efficacy of the intervention, an A-B-A quasi-experimental design was used, in which the involved child was repeatedly evaluated before, during and after treatment. The results showed that robotics activities produced significant changes in his fine motor skills, verbal and preverbal skills, social reciprocity and emotional expression. Furthermore, it was possible to o…
Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles
2009
[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…
Improved calculations of beta decay backgrounds to new physics in liquid xenon detectors
2020
We present high-precision theoretical predictions for the electron energy spectra for the ground-state to ground-state $\beta$ decays of $^{214}$Pb, $^{212}$Pb, and $^{85}$Kr most relevant to the background of liquid xenon dark matter detectors. The effects of nuclear structure on the spectral shapes are taken into account using large-scale shell model calculations. Final spectra also include atomic screening and exchange effects. The impact of nuclear structure effects on the $^{214}$Pb and $^{212}$Pb spectra below $\approx100$ keV, pertinent for several searches for new physics, are found to be comparatively larger than those from the atomic effects alone. We find that the full calculatio…
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…