Now showing items 802-821 of 988

    • Sample size impact on the categorisation of continuous variables in clinical prediction 

      Barrio I.; Arostegui I.; Rodríguez-Álvarez M.X. (Trends in Mathematics. Research Perspectives CRM Barcelona. Extended Abstracts Fall 2015. Biomedical Big Data; Statistics for Low Dose Radiation Research, 2017-12)
      Recent advances in information technologies are generating a growth in the amount of available biomedical data. In this paper, we studied the impact sample size may have on the categorisation of a continuous predictor ...
    • Scaling law of diffusivity generated by a noisy telegraph signal with fractal intermittency 

      Paradisi P.; Allegrini P. (Chaos, Solitons and Fractals, 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 ...
    • Scheduling of users with Markovian time-varying transmission rates 

      Cecchi F.; Jacko P. (Performance Evaluation Review, 2013-12-31)
      We address the problem of developing a well-performing and implementable scheduler of users with wireless connection to the base station. The main feature of such real-life systems is that the quality conditions of the ...
    • Schrödinger operators with boundary singularities: Hardy inequality, Pohozaev identity and controllability results 

      Cazacu C. (Journal of Functional Analysis, 2012-12-31)
      The aim of this paper is two folded. Firstly, we study the validity of a Pohozaev-type identity for the Schrödinger operator A λ:=-δ-λ/|x| 2, λ∈R, in the situation where the origin is located on the boundary of a smooth ...
    • SDE-driven modeling of phenotypically heterogeneous tumors: The influence of cancer cell stemness 

      Kroos J.M.; Stinner C.; Surulescu S.; Surulescu N. (Discrete and Continuous Dynamical Systems - Series B, 2019)
      We deduce cell population models describing the evolution of a tumor (possibly interacting with its environment of healthy cells) with the aid of differential equations. Thereby, different subpopulations of cancer cells ...
    • Second moment constraints and the control problem of Markov jump linear systems 

      Vargas A.N.; Furloni W.; Do Val J.B.R. (Numerical Linear Algebra with Applications, 2013-12-31)
      This paper addresses the optimal solution for the regulator control problem of Markov jump linear systems subject to second moment constraints. We can characterize and obtain the solution explicitly using linear matrix ...
    • Self-Adjoint Extensions for the Dirac Operator with Coulomb-Type Spherically Symmetric Potentials 

      Cassano B.; Pizzichillo F. (Letters in Mathematical Physics, 2018)
      We describe the self-adjoint realizations of the operator $H:=-i\alpha\cdot \nabla + m\beta + \mathbb V(x)$, for $m\in\mathbb R $, and $\mathbb V(x)= |x|^{-1} ( \nu \mathbb{I}_4 +\mu \beta -i \lambda \alpha\cdot{x}/{|x|}\,\beta)$, ...
    • Self-similar stochastic models with stationary increments for symmetric space-time fractional diffusion 

      Pagnini G. (MESA 2014 - 10th IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, Conference Proceedings, 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, ...
    • Semi-analytical response of acoustic logging measurements in frequency domain 

      Muga I.; Pardo D.; Matuszyk P.J.; Torres-Verdin C. (Computers and Mathematics with Applications, 2015-12-31)
      This work proposes a semi-analytical method for simulation of the acoustic response of multipole eccentered sources in a fluid-filled borehole. Assuming a geometry that is invariant with respect to the azimuthal and vertical ...
    • A semi-discrete large-time behavior preserving scheme for the augmented Burgers equation 

      Ignat L.I.; Pozo A. (ESAIM: Mathematical Modelling and Numerical Analysis, 2017-06-01)
      In this paper we analyze the large-time behavior of the augmented Burgers equation. We first study the well-posedness of the Cauchy problem and obtain $L^1-L^p$ decay rates. The asymptotic behavior of the solution is ...
    • Semi-markov graph dynamics 

      Raberto M.; Rapallo F.; Scalas E. (PLoS ONE, 2011-12-31)
      In this paper, we outline a model of graph (or network) dynamics based on two ingredients. The first ingredient is a Markov chain on the space of possible graphs. The second ingredient is a semi-Markov counting process of ...
    • Semialgebraic CMC surfaces in $\mathbb{R}^3$ with singularities 

      Sampaio J. E. (2018-06-30)
      In this paper we present a classification of a class of semialgebraic CMC surfaces in $\mathbb{R}^3$ that generalizes the recent classification made by Barbosa and do Carmo in 2016 (complete reference is in the paper), we ...
    • Sensitivity analysis of 1-d steady forced scalar conservation laws 

      Ersoy M.; Feireisl E.; Zuazua E. (Journal of Differential Equations, 2013-12-31)
      We analyze 1 - d forced steady state scalar conservation laws. We first show the existence and uniqueness of entropy solutions as limits as t→ ∞ of the corresponding solutions of the scalar evolutionary hyperbolic conservation ...
    • Sensitivity study of borehole-to-surface and crosswell electromagnetic measurements acquired with energized steel casing to water displacement in hydrocarbon-bearing layers 

      Pardo D.; Torres-Verdín C.; Zhang Z. (Geophysics, 2008-12-31)
      We study the theoretical response of electromagnetically energized steel casing in the presence of subsurface variations of electrical resistivity. Casing is energized with a finite-size solenoid antenna located along the ...
    • Sentiment analysis with genetically evolved Gaussian kernels 

      Roman I.; Santana R.; Mendiburu A.; Lozano J.A. (GECCO '19 Proceedings of the Genetic and Evolutionary Computation Conference, 2019)
      Sentiment analysis consists of evaluating opinions or statements based on text analysis. Among the methods used to estimate the degree to which a text expresses a certain sentiment are those based on Gaussian Processes. ...
    • Shallow-shell models by Γ-convergence 

      Velčić I. (Mathematics and Mechanics of Solids, 2012-12-31)
      In this paper we derive, by means of Γ-convergence, the shallow-shell models starting from non-linear three-dimensional elasticity. We use the approach analogous to the one for shells and plates. We start from the minimization ...
    • Sharp bounds for the ratio of modified Bessel functions 

      Zheng S.; Yang Z-H. (Mediterranean Journal of Mathematics, 2017-06-21)
      Let $I_{\nu }\left( x\right) $ be the modified Bessel functions of the first kind of order $\nu $, and $S_{p,\nu }\left( x\right) =W_{\nu }\left( x\right) ^{2}-2pW_{\nu }\left( x\right) -x^{2}$ with $W_{\nu }\left( x\right) ...
    • Sharp exponential localization for eigenfunctions of the Dirac Operator 

      Cassano B. (2018)
      We determine the fastest possible rate of exponential decay at infinity for eigenfunctions of the Dirac operator $\mathcal D_n + \mathbb V$, being $\mathcal D_n$ the massless Dirac operator in dimensions $n=2,3$ and ...
    • Sharp Observability Estimates for Heat Equations 

      Ervedoza S.; Zuazua E. (Archive for Rational Mechanics and Analysis, 2011-12-31)
      The goal of this article is to derive new estimates for the cost of observability of heat equations. We have developed a new method allowing one to show that when the corresponding wave equation is observable, the heat ...
    • Sharp weighted estimates involving one supremum 

      Li K. (Comptes Rendus Mathematique, 2017-07)
      In this note, we study the sharp weighted estimate involving one supremum. In particular, we give a positive answer to an open question raised by Lerner and Moen. We also extend the result to rough homogeneous singular ...