Results 1 to 10 of about 18,081 (306)
Total Positivity and Convexity Preservation
Journal of Approximation Theory, 1999 In this paper we define convexity and rational convexity preservation of systems of functions and we show that total positivity and rational convexity preservation are equivalent. We also characterize certain convexity preserving systems in terms of weak
Michael S Floater
exaly +4 more sources
Preservation of external positivity in discretization of linear systems
European Journal of Control, 2021 We study the preservation of impulse response non-negativity, also known as external positivity, for general discretization methods. The results yield new subsets in the space of transfer function coefficients which ensure external positivity ...
Hamed Taghavian
exaly +2 more sources
Positivity-Preserving Rational Cubic Fractal Interpolation Function Together with Its Zipper Form [PDF]
AxiomsIn this paper, a novel class of rational cubic fractal interpolation function (RCFIF) has been proposed, which is characterized by one shape parameter and a linear denominator.
Shamli Sharma +4 more
doaj +2 more sources
Positivity preservation of implicit discretizations of the advection equation [PDF]
, 2021 We analyze, from the viewpoint of positivity preservation, certain discretizations of a fundamental partial differential equation, the one-dimensional advection equation with periodic boundary condition.
Ketcheson, David I. +2 more
core +4 more sources
Mathematics, 2023 The basic model motivating this work is that of contaminant transport in the Earth’s subsurface, which contains layers in which analytical and semi-analytical solutions of the corresponding advection–dispersion equations could be derived. Then, using the
Miglena N. Koleva, Lubin G. Vulkov
doaj +1 more source
Efficient Numerical Solutions to a SIR Epidemic Model
Mathematics, 2022 Two non-standard predictor-corrector type finite difference methods for a SIR epidemic model are proposed. The methods have useful and significant features, such as positivity, basic stability, boundedness and preservation of the conservation laws.
Mohammad Mehdizadeh Khalsaraei +4 more
doaj +1 more source
Antibodies, 2021 Purpose: Response to anti-PD-L1/PD-1 immunotherapy correlates with PD-L1 expression in breast cancer. However, the prevalence of PD-L1 positive breast cancer is variable, which could be due to differences in the population/cohort of patients tested or ...
Hazem Ghebeh +8 more
doaj +1 more source
Numerical solution of the brusselator model by time splitting method
Cumhuriyet Science Journal, 2021 One of the significant models in chemical reactions with oscillations is the Brusselator model. This model essentially describes a nonlinear reaction-diffusion equation. Brusselator system arises in applications of many physical and chemical models.
Yeşim Çiçek +1 more
doaj +1 more source
Shape-Preservation of the Four-Point Ternary Interpolating Non-stationary Subdivision Scheme
Frontiers in Physics, 2020 In this paper, we present the shape-preserving properties of the four-point ternary non-stationary interpolating subdivision scheme (the four-point scheme). This scheme involves a tension parameter.
Pakeeza Ashraf +4 more
doaj +1 more source
Construction of propagators for divisible dynamical maps
New Journal of Physics, 2021 Divisible dynamical maps play an important role in characterizing Markovianity on the level of quantum evolution. Divisible maps provide an important generalization of Markovian semigroups. Usually one analyzes either completely positive or just positive
Ujan Chakraborty, Dariusz Chruściński
doaj +1 more source