Results 41 to 50 of about 548,121 (295)
An Unconditional Positivity-Preserving Difference Scheme for Models of Cancer Migration and Invasion
Mathematics, 2022 In this paper, we consider models of cancer migration and invasion, which consist of two nonlinear parabolic equations (one of the convection–diffusion reaction type and the other of the diffusion–reaction type) and an additional nonlinear ordinary ...
Mikhail K. Kolev +2 more
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Issues with positivity-preserving Patankar-type schemes
Applied Numerical Mathematics, 2022 Patankar-type schemes are linearly implicit time integration methods designed to be unconditionally positivity-preserving. However, there are only little results on their stability or robustness. We suggest two approaches to analyze the performance and robustness of these methods.
Davide Torlo +2 more
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\({K}\)-Positivity Preservers and Their Generators
SIAM Journal on Applied Algebra and GeometryWe study $K$-positivity preservers with given closed $K\subseteq\mathbb{R}^n$, i.e., linear maps $T:\mathbb{R}[x_1,\dots,x_n]\to\mathbb{R}[x_1,\dots,x_n]$ such that $T\mathrm{Pos}(K)\subseteq\mathrm{Pos}(K)$ holds, and their generators $A:\mathbb{R}[x_1,\dots,x_n]\to\mathbb{R}[x_1,\dots,x_n]$, i.e., $e^{tA}\mathrm{Pos}(K)\subseteq\mathrm{Pos}(K)$ holds
Philipp Di Dio, Konrad Schmüdgen
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A positivity-preserving unigrid method for elliptic PDEs
CoRR, 2023 While constraints arise naturally in many physical models, their treatment in mathematical and numerical models varies widely, depending on the nature of the constraint and the availability of simulation tools to enforce it. In this paper, we consider the solution of discretized PDE models that have a natural constraint on the positivity (or non ...
Ronald D. Haynes +2 more
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Bases for shape preserving curves
Journal of Numerical Analysis and Approximation Theory, 2003 The shape preserving properties of a curve in \(\mathbb{R}^2\) depend on the properties of the function basis we use in its representation. Both sign consistent and totally positive bases have shape preserving properties useful in Computer Aided ...
Francesca Pitolli
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Journal of Advanced Transportation, 2023 The macroscopic models for solving the pedestrian flow problem can be generally classified into two categories as follows: first-order continuum models and high-order continuum models.
L. Yang, H. Liang, J. Du, S. C. Wong
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Structure preserving numerical scheme for spatio-temporal epidemic model of plant disease dynamics
Results in Physics, 2021 In this article, an implicit numerical design is formulated for finding the numerical solution of spatiotemporal nonlinear dynamical system with advection. Such type of problems arise in many fields of life sciences, mathematics, physics and engineering.
Shumaila Azam +6 more
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, 2017 This paper is being completely rewritten, with the focus now on kernels on arbitrary domains, and the ensuing analysis. This includes Polya frequency functions/sequences, Hankel and other Toeplitz kernels, and the study of their ...
Belton, Alexander +3 more
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Mathematics, 2022 In this paper, we evaluate and discuss different numerical methods to solve the Black–Scholes equation, including the θ-method, the mixed method, the Richardson method, the Du Fort and Frankel method, and the MADE (modified alternating directional ...
Mohammad Mehdizadeh Khalsaraei +4 more
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Pediatric Blood &Cancer, EarlyView.ABSTRACT Pediatric gastroenteropancreatic neuroendocrine neoplasms (GEP‐NENs) are extremely rare and clinically heterogeneous. Management has largely been extrapolated from adult practice. This European Standard Clinical Practice Guideline (ESCP), developed by the EXPeRT network in collaboration with adult NEN experts, provides (adult) evidence ...
Michaela Kuhlen +23 more
wiley +1 more source