Results 261 to 270 of about 7,957,612 (305)

Positivity Preservation Properties of the Rantzer Multipliers

IEEE Transactions on Automatic Control, 2011
The Rantzer multipliers are known to preserve the positivity of certain aberrations of memoryless monotone positive nonlinearities. We show that if the nonlinearity input is constrained to be positive valued for all time instants, these multipliers are positivity preserving for a larger class of nonlinearities.
Vishwesh V. Kulkarni 0001, Lucy Y. Pao, Michael G. Safonov   +2 more
openaire   +1 more source

Positivity preserving and mass conservative projection method for the Poisson-Nernst-Planck equation

SIAM Journal on Numerical Analysis
We propose and analyze a novel approach to construct structure preserving approximations for the Poisson-Nernst-Planck equations, focusing on the positivity preserving and mass conservation properties.
Fenghua Tong, Yongyong Cai
semanticscholar   +1 more source

On the Positivity Preserving Property of Hinged Plates

SIAM Journal on Mathematical Analysis, 2009
In this work we show that the Kirchhoff–Love model for a hinged plate $\Delta^2 v = f \text{ in }E,\; v = \Delta v - (1 - \sigma) \kappa v_n = 0 \text{ on }\partial E$ admits, for $f \in L^2(E)$ and $-1 < \sigma < 1$, a unique weak solution in $W^{2,2}(E) \cap W^{1,2}_0(E)$ which satisfies the positivity preserving property when $E \subset \mathbb{R}^2$
Enea Parini, Athanasios Stylianou
openaire   +2 more sources

Positivity-preserving H∞ model reduction for positive systems.

Autom., 2011
This paper is concerned with the model reduction of positive systems. For a given stable positive system, our attention is focused on the construction of a reduced-order model in such a way that the positivity of the original system is preserved and the error system is stable with a prescribed H ∞ performance. Based upon a system augmentation approach,
Ping Li 0004, James Lam, Zidong Wang 0001, Paresh Date   +3 more
openaire   +3 more sources

Internal positivity preserved model reduction

International Journal of Control, 2009
This article studies model reduction of continuous-time stable positive linear systems under the Hankel norm, H ∞ norm and H 2 norm performance. The reduced-order systems preserve the stability as well as the positivity of the original systems. This is achieved by developing new necessary and sufficient conditions of the model reduction performances in
Jun-e Feng, James Lam, Zhan Shu 0001, Qing Wang 0051   +3 more
openaire   +3 more sources

A well-balanced positivity-preserving numerical scheme for shallow water models with variable density

Computers & Fluids, 2021
We develop an unstructured numerical scheme for a coupled system modeling shallow water flows and solute transport over variable topography. A novel algorithm is introduced for the reconstructions of the variables of the system with variable density ...
Amine Hanini, A. Beljadid, D. Ouazar
semanticscholar   +1 more source

The L ∞ $L^{\infty }$ -positivity Preserving P

Potential Analysis, 2021
We say that a Riemannian manifold satisfies the L ^ p -positivity preserving property if (−Δ + 1) u ≥ 0 in a distributional sense implies u ≥ 0 for all u ∈ L ^ p .
Andrea Bisterzo, Ludovico Marini
semanticscholar   +1 more source

Preserving positive realness through discretization

Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334), 2000
Continuous linear systems with positive real transfer functions have desirable stability and realizability properties. The conditions to guarantee that continuous positive realness is preserved under discretization by a standard sampler and zero order hold are investigated here.
openaire   +2 more sources

Nica’s q-Convolution is Not Positivity Preserving

Communications in Mathematical Physics, 2005
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +2 more sources

Positivity-Preserving Scattered Data Interpolation

2005
The construction of a C1 interpolant to scattered data is considered in which the interpolant is positive everywhere if the original data are positive. This study is motivated by earlier work in which sufficient conditions are derived on Bezier points in order to ensure that surfaces comprising cubic Bezier triangular patches are always positive.
Abd. Rahni Mt. Piah, Tim N. T. Goodman, Keith Unsworth   +2 more
openaire   +1 more source