Now showing items 35-54 of 60

• #### Quasi-probability Approach for Modelling Local Extinction and Counter-gradient in Turbulent Premixed Combustion ﻿

(2018-05-23)
In opposition to standard probability distributions, quasi-probability distributions can have negative values which highlight nonclassical properties of the corresponding system. In quantum mechanics, such negative values ...
• #### The random diffusivity approach for diffusion in heterogeneous systems ﻿

(2020-12-16)
The two hallmark features of Brownian motion are the linear growth $\langle x^2(t) \rangle = 2 D d t$ of the mean squared displacement (MSD) with diffusion coefficient $D$ in $d$ spatial dimensions, and the Gaussian ...
• #### Random diffusivity from stochastic equations: comparison of two models for Brownian yet non-Gaussian diffusion ﻿

(2018-04)
A considerable number of systems have recently been reported in which Brownian yet non-Gaussian dynamics was observed. These are processes characterised by a linear growth in time of the mean squared displacement, yet the ...
• #### RandomFront 2.3 A physical parametrisation of fire-spotting for operational fire spread models: Implementation in WRF-Sfire and response analysis with LSFire+ ﻿

(2018-12)
Fire-spotting is often responsible for a dangerous flare up in the wildfire and causes secondary ignitions isolated from the primary fire zone leading to perilous situations. The main aim of the present research to provide ...
• #### Reduced description method in the kinetic theory of Brownian motion with active fluctuations ﻿

(2019-09-01)
We develop a microscopic approach to the kinetic theory of many-particle systems with dissipative and potential interactions in presence of active fluctuations. The approach is based on a generalization of Bogolyubov–Peletminskii ...
• #### A renewal model for the emergence of anomalous solute crowding in liposomes ﻿

(2015-12-31)
A fundamental evolutionary step in the onset of living cells is thought to be the spontaneous formation of lipid vesicles (liposomes) in the pre-biotic mixture. Even though it is well known that hydrophobic forces drive ...
• #### Restoring property of the Michelson-Sivashinsky equation ﻿

(2019)
In this paper we propose a derivation of the Michelson-Sivashinsky (MS) equation that is based on front propagation only, in opposition to the classical derivation based also on the flow field. Hence, the characteristics ...
• #### The role of the environment in front propagation ﻿

(2018-07-09)
In this work we study the role of a complex environment in the propagation of a front with curvature-dependent speed. The motion of the front is split into a drifting part and a fluctuating part. The drifting part is ...
• #### Scaling law of diffusivity generated by a noisy telegraph signal with fractal intermittency ﻿

(2015-12-31)
In many complex systems the non-linear cooperative dynamics determine the emergence of self-organized, metastable, structures that are associated with a birth-death process of cooperation. This is found to be described by ...
• #### Self-similar stochastic models with stationary increments for symmetric space-time fractional diffusion ﻿

(2014-12-31)
An approach to develop stochastic models for studying anomalous diffusion is proposed. In particular, in this approach the stochastic particle trajectory is based on the fractional Brownian motion but, for any realization, ...
• #### Short note on the emergence of fractional kinetics ﻿

(2014-12-31)
In the present Short Note an idea is proposed to explain the emergence and the observation of processes in complex media that are driven by fractional non-Markovian master equations. Particle trajectories are assumed to ...
• #### SHOULD I STAY OR SHOULD I GO? ZERO-SIZE JUMPS IN RANDOM WALKS FOR LÉVY FLIGHTS ﻿

(2021-02)
We study Markovian continuous-time random walk models for Lévy flights and we show an example in which the convergence to stable densities is not guaranteed when jumps follow a bi-modal power-law distribution that is equal ...
• #### Single-trajectory spectral analysis of scaled Brownian motion ﻿

(2019-06)
A standard approach to study time-dependent stochastic processes is the power spectral density (PSD), an ensemble-averaged property defined as the Fourier transform of the autocorrelation function of the process in the ...
• #### Stochastic processes for anomalous diffusion ﻿

(2019)
Anomalous diffusion is a diffusion process which Mean Square Displacement (MSD) is not a linear funtion of time, what is known as normal diffusion. When the relation is faster than linear, it is called superdiffusion and ...
• #### Stochastic resetting by a random amplitude ﻿

(2021-05-18)
Stochastic resetting, a diffusive process whose amplitude is reset to the origin at random times, is a vividly studied strategy to optimize encounter dynamics, e.g., in chemical reactions. Here we generalize the resetting ...
• #### Stochastic spatial models in ecology: a statistical physics approach ﻿

(2017-11-21)
Ecosystems display a complex spatial organization. Ecologists have long tried to characterize them by looking at how different measures of biodiversity change across spatial scales. Ecological neutral theory has provided ...
• #### Study of Wound Healing Dynamics by Single Pseudo-Particle Tracking in Phase Contrast Images Acquired in Time-Lapse ﻿

(2021-03)
Cellular contacts modify the way cells migrate in a cohesive group with respect to a free single cell. The resulting motion is persistent and correlated, with cells’ velocities self-aligning in time. The presence of a dense ...
• #### Surrogate based Global Sensitivity Analysis of ADM1-based Anaerobic Digestion Model ﻿

(2021)
In order to calibrate the model parameters, Sensitivity Analysis routines are mandatory to rank the parameters by their relevance and fix to nominal values the least influential factors. Despite the high number of works ...
• #### Surrogate-based uncertainty and sensitivity analysis for bacterial invasion in multi-species biofilm modeling ﻿

(2019)
In this work, we present a probabilistic analysis of a detailed one-dimensional biofilm model that explicitly accounts for planktonic bacterial invasion in a multi-species biofilm. The objective is (1) to quantify and ...
• #### Turbulence and fire-spotting effects into wild-land fire simulators ﻿

(2016-01-01)
This paper presents a mathematical approach to model the effects and the role of phenomena with random nature such as turbulence and fire-spotting into the existing wildfire simulators. The formulation proposes that the ...