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Now showing items 1-10 of 10

#### On the merits of sparse surrogates for global sensitivity analysis of multi-scale nonlinear problems: Application to turbulence and fire-spotting model in wildland fire simulators

(Communications in Nonlinear Science and Numerical Simulation, 2019-02)

Many nonlinear phenomena, whose numerical simulation is not straightforward, depend on a set of parameters in a way which is not easy to predict beforehand. Wildland fires in presence of strong winds fall into this category, ...

#### Finite-energy Lévy-type motion through heterogeneous ensemble of Brownian particles

(Journal of Physics A: Mathematical and Theoretical, 2019-02-01)

Complex systems are known to display anomalous diffusion, whose signature is a space/time scaling $x \sim t^\delta$ with $\delta \neq 1/2$ in the probability density function (PDF). Anomalous diffusion can emerge jointly ...

#### Fire-spotting generated fires. Part I: The role of atmospheric stability

(Applied Mathematical Modelling, 2019-02)

This is the first part of two papers concerning fire-spotting generated fires. In this part we deal with the impact of macroscale factors, such as the atmospheric stability, and in the second part we deal with mesoscale ...

#### Fractional Brownian motion in a finite interval: correlations effect depletion or accretion zones of particles near boundaries

(New Journal of Physics, 2019-02)

Fractional Brownian motion (FBM) is a Gaussian stochastic process with stationary, long-time correlated increments and is frequently used to model anomalous diffusion processes. We study numerically FBM confined to a finite ...

#### Accuracy of Classical Conductivity Theory at Atomic Scales for Free Fermions in Disordered Media

(J. Math. Pures Appl., 2019-01-22)

The growing need for smaller electronic components has recently sparked the interest in the breakdown of the classical conductivity theory near the atomic scale, at which quantum effects should dominate. In 2012, experimental ...

#### The Discreteness-driven Relaxation of Collisionless Gravitating Systems: Entropy Evolution in External Potentials, N-dependence, and the Role of Chaos

(The Astrophysical Journal, 2019-01-10)

We investigate the old problem of the fast relaxation of collisionless N-body systems that are collapsing or perturbed,
emphasizing the importance of (noncollisional) discreteness effects. We integrate orbit ensembles in ...

#### A jacobian module for disentanglements and applications to Mond's conjecture

(Revista Matemática Complutense, 2019)

Let $f:(\mathbb C^n,S)\to (\mathbb C^{n+1},0)$ be a germ whose image is given by $g=0$. We define an $\mathcal O_{n+1}$-module $M(g)$ with the property that $\mathscr A_e$-$\operatorname{codim}(f)\le \dim_\mathbb C M(g)$, ...

#### Modeling non-stationarities in high-frequency financial time series

(Physica A: Statistical Mechanics and its Applications, 2019-01)

We study tick-by-tick financial returns for the FTSE MIB index of the Italian Stock Exchange (Borsa Italiana). We confirm previously detected non-stationarities. Scaling properties reported before for other high-frequency ...

#### Surrogate-based uncertainty and sensitivity analysis for bacterial invasion in multi-species biofilm modeling

(Communications Nonlinear Sciences and Numerical Simulation, 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 ...

#### Fractional kinetics in random/complex media

(Handbook of Fractional Calculus with Applications Volume 5 Applications in Physics, Part B, 2019)

In this chapter, we consider a randomly-scaled Gaussian process and discuss a number of applications to model fractional diffusion. Actually, this approach can be understood as a Gaussian diffusion in a medium characterized ...