Listar MAT_Articles por autoría "617ad8f9-df91-4f1e-8a09-526546950d81"
Mostrando ítems 1-20 de 30
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A modified perturbation method for mathematical models with randomness: An analysis through the steady-state solution to Burgers’ PDE
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc John Wiley and Sons (2020-04-12)The variability of the data and the incomplete knowledge of the true physics require the incorporation of randomness into the formulation of mathematical models. In this setting, the deterministic numerical methods cannot ... -
A new population model for urban infestations
Calatayud, Julia; Jornet, Marc; Mateu, Jorge; Pinto, Carla M. A. Elsevier (2023-10-10)The spread of rodents and insects in cities, in particular in summer periods, poses significant health, economic, social and environmental threats. The analysis of incidence and identification of seasonal and weather ... -
A phenomenological model for COVID-19 data taking into account neighboring-provinces effect and random noise
Calatayud, Julia; Jornet, Marc; Mateu, Jorge Wiley (2022)We model the incidence of the COVID-19 disease during the first wave of the epidemic in Castilla-Leon (Spain). Within-province dynamics may be governed by a generalized logistic map, but this lacks of spatial structure. ... -
A stochastic Bayesian bootstrapping model for COVID-19 data
Calatayud, Julia; Jornet, Marc; Mateu, Jorge Springer (2022-01-11)We provide a stochastic modeling framework for the incidence of COVID-19 in Castilla-Leon (Spain) for the period March 1, 2020 to February 12, 2021, which encompasses four waves. Each wave is appropriately described by a ... -
An improvement of two nonstandard finite difference schemes for two population mathematical models
Calatayud, Julia; Jornet, Marc Taylor and Francis (2021-03-26)The aim of this paper is to design appropriate nonstandard finite difference (NSFD) schemes for two population mathematical models based on coupled nonlinear ordinary differential equations. Our work clarifies existing ... -
Una aplicación del teorema del valor medio para estudiar series numéricas
Burgos, Clara; Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc Una aplicación del teorema del valor medio para estudiar series numéricas (2021-10)In this note we show an application of the mean value theorem to derive the convergence/divergence of numerical series. In particular, our analysis allows us to derive the convergence of p-series and to derive the classical ... -
Computational uncertainty quantification for random non-autonomous second order linear differential equations via adapted gPC: a comparative case study with random Fröbenius method and Monte Carlo simulation
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc De Gruyter (2018-12)This paper presents a methodology to quantify computationally the uncertainty in a class of differential equations often met in Mathematical Physics, namely random non-autonomous second-order linear differential equations, ... -
Computational uncertainty quantification for random time‐discrete epidemiological models using adaptive gPC
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc; Villanueva, Rafael-Jacinto John Wiley & Sons, Ltd. (2018-10-22)Population dynamics models consisting of nonlinear difference equations allow us to get a better understanding of theprocesses involved in epidemiology. Usually, these mathematical models are studied under a deterministic ... -
Dealing with variability in ecological modelling: An analysis of a random non-autonomous logistic population model
Calatayud, Julia; Cortés, Juan Carlos; Dorini, Fabio Antonio; Jornet, Marc John Wiley & Sons, Ltd. (2021-05-09)This paper presents a methodology to deal with the randomness associated toecological modelling. Data variability makes it necessary to analyse the impactof random perturbations on the fitted model parameters. We conduct ... -
Exact solution to a multidimensional wave equation with delay
Jornet, Marc Elsevier (2021-06-15)This paper deals with a mixed problem for the wave equation with discrete delay τ>0, utt (t , x) = a 1 2 Δx u (t,x) + a 2 2 Δx u (t – τ , x) + b1u (t,x) + b2u (t−τ,x), t > τ,0 ≤ x ≤ l,with Dirichlet boundary conditions. ... -
Extending the applicability of the RVT technique for the randomized radioactive decay chain model
Calatayud, Julia; Jornet, Marc Springer (2022-03-30)In this paper, we improve the existing analysis on the randomized radioactive decay chain model based on Bateman master equations, by Hussein and Selim (2020). For a decay chain of three species of radionuclides, the authors ... -
Frailty Assessment in a Stable COPD Cohort: Is There a COPD-Frail Phenotype?
NAVAL, ELSA; González, Maria Cruz; Giraldós, Sonia; Calatayud, Julia; Jornet, Marc; Lluch, Inmaculada; Meseguer, Maria; Ruiz Cubillan, Juan Jose; Viña, José; Tarazona-Santabalbina, Francisco José Taylor & Francis (2021-09-09)The frailty syndrome increases the morbidity/mortality in older adults, and several studies have shown a higher prevalence of this syndrome in patients with Chronic Obstructive Pulmonary Disease (COPD). The aim of this ... -
Improving the Approximation of the First- and Second-Order Statistics of the Response Stochastic Process to the Random Legendre Differential Equation
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc Springer Nature Switzerland AG (2019-04-16)In this paper, we deal with uncertainty quantification for the random Legendre differential equation, with input coefficient A and initial conditions X0 and X1. In a previous study (Calbo et al. in Comput Math Appl ... -
Improving the approximation of the probability density function of random nonautonomous logistic-type differential equations
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc John Wiley & Sons, Ltd. (2019-08-16)In this paper, we address the problem of approximating the probability density function of the following random logistic differential equation: P ′ (t, 𝜔�) = A(t, 𝜔�)(1 − P(t, 𝜔�))P(t, 𝜔�), t ∈ [t0, T], P(t0, 𝜔�) ... -
Liouville’s equations for random systems
Jornet, Marc Taylor and Francis (2021-10-03)Given a random system, a Liouville’s equation is an exact partial differential equation that describes the evolution of the probability density function of the solution. In this paper, we derive Liouville’s equations for ... -
Lp-calculus Approach to the Random Autonomous Linear Differential Equation with Discrete Delay
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc Springer Nature Switzerland AG (2019-06-19)In this paper, we provide a full probabilistic study of the random autonomous linear differential equation with discrete delay τ > 0: x (t) = ax(t) + bx(t − τ ), t ≥ 0, with initial condition x(t) = g(t), −τ ≤ t ≤ 0. ... -
Modeling noisy time-series data of crime with stochastic differential equations
Calatayud, Julia; Jornet, Marc Springer (2022-11-01)We develop and calibrate stochastic continuous models that capture crime dynamics in the city of Valencia, Spain. From the emergency phone, data corresponding to three crime events, aggressions, stealing and women alarms, ... -
Modeling of adulthood obesity in Spain using Itô-type stochastic differential equations
Calatayud, Julia; Jornet, Marc Elsevier (2021-02-25)Obesity is growing riskily in developed and developing countries. This should pose major concerns for the countries, not only from the health point, but also from the economic perspective. Our case study relies on the ... -
On the convergence of adaptive gPC for non-linear random difference equations: Theoretical analysis and some practical recommendations
Calatayud, Julia; Cortés, Juan Carlos; Jornet, Marc International Scientific Research Publications (2018-06-19)In this paper, the application of adaptive generalized polynomial chaos (gPC) to quantify the uncertainty for non-linear random difference equations is analyzed. It is proved in detail that, under certain assumptions, the ... -
On the convergence of the mild random walk algorithm to generate random one-factorizations of complete graphs
Calatayud, Julia; Jornet, Marc Taylor and Francis (2020-05-13)The complete graph Kn, for n even, has a one-factorization (proper edge coloring) with n – 1 colors. In the recent contribution [Dotan M., Linial N. (2017). ArXiv:1707.00477v2], the authors raised a conjecture on the ...