Results 41 to 50 of about 15,388 (303)

Efficient Positivity-Preserving NSFD Scheme: Application to Advection-Diffusion-Reaction Equation [PDF]

Journal of Applied and Computational Mechanics
Solving problems across a wide range of scientific and engineering domains, encompassing physical, mechanical and biological systems as well as financial markets, necessitates addressing parabolic equations of the advection-diffusion-reaction (ADR ...
Reza Shokri Jahandizi, Mohammad Mehdizadeh Khalsaraei, Ali Shokri, Ali Khani   +3 more
doaj   +1 more source

\({K}\)-Positivity Preservers and Their Generators

SIAM Journal on Applied Algebra and Geometry
We 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
openaire   +2 more sources

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
doaj   +2 more sources

Positivity of solutions to the Cauchy problem for linear and semilinear biharmonic heat equations

Advances in Nonlinear Analysis, 2020
This paper is concerned with the positivity of solutions to the Cauchy problem for linear and nonlinear parabolic equations with the biharmonic operator as fourth order elliptic principal part. Generally, Cauchy problems for parabolic equations of fourth
Grunau Hans-Christoph, Miyake Nobuhito, Okabe Shinya   +2 more
doaj   +1 more source

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, Nauman Ahmed, Ali Akgül, Muhammad Sajid Iqbal, Muhammad Rafiq, Muhammad Ozair Ahmad, Dumitru Baleanu   +6 more
doaj   +1 more source

Fitting Constrained Continuous Spline Curves. [PDF]

, 2003
Fitting a curve through a set of planar data which represents a positive quantity requires that the curve stays above the horizontal axis, The more general problem of designing parametric and non-parametric curves which do not cross the given constraint
Ong, B. H., Kong, V.P.
core  

European Standard Clinical Practice Guideline and EXPeRT Recommendations for the Diagnosis and Management of Gastroenteropancreatic Neuroendocrine Neoplasms in Children and Adolescents

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, Calogero Virgone, Antje Redlich, Michael Abele, Ricardo Lopez‐Almaraz, Tal Ben‐Ami, Ewa Bien, Gianni Bisogno, Maja Mazic Cesen, Andrea Ferrari, Malgorzata A. Krawczyk, Yves Reguerre, Dominik T. Schneider, Ines B. Brecht, Charlotte Rigaud, Bilgehan Yalcin, Rainer Claus, Christian Vokuhl, Constantin Lapa, Jörg Fuchs, Segolene Hescot, Thomas Walter, Julien Hadoux, Daniel Orbach   +23 more
wiley   +1 more source

Arbitrary order positivity preserving finite-volume schemes for 2D elliptic problems

, 2023
International audienceThe positivity preservation is very important in most applications solving elliptic problems. Many schemes preserving positivity has been proposed but are at most second-order convergent.
Blanc, Xavier, Hermeline, Francois, Labourasse, Emmanuel, Patela, Julie   +3 more
core   +1 more source

Positivity-Preserving Discontinuous Galerkin Methods on Triangular Meshes for Macroscopic Pedestrian Flow Models

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
doaj   +1 more source

Total Positivity and Convexity Preservation

Journal of Approximation Theory, 1999
In this paper the author introduces a concept of \(d\)-convexity of curves in the \(d\)-dimensional space and characterizes totally positive blending systems in terms of \(d\)-convexity. He shows that for certain systems total positivity and rational convexity preservation are equivalent.
openaire   +2 more sources