Many dynamical systems described by nonlinear ODEs are unstable. Their associated solutions do not converge towards an equilibrium point, but rather converge towards some invariant subset of the state space called an attractor set. For a given ODE, in general, the existence, shape and structure of the attractor sets of the ODE are unknown. Fortunately, the sublevel sets of Lyapunov functions can provide bounds on the attractor sets of ODEs. In this paper we propose a new Lyapunov characterization of attractor sets that is well suited to the problem of finding the minimal attractor set. We show our Lyapunov characterization is nonconservative even when restricted to SumofSquares (SOS) Lyapunov functions. Given these results, we propose a SOS programming problem based on determinant maximization that yields an SOS Lyapunov function whose
Genetic variations in the COVID19 virus are one of the main causes of the COVID19 pandemic outbreak in 2020 and 2021. In this article, we aim to introduce a new type of model, a system coupled with ordinary differential equations (ODEs) and measure differential equation (MDE), stemming from the classical SIR model for the variants distribution. Specifically, we model the evolution of susceptible
 Award ID(s):
 2033580
 NSFPAR ID:
 10341804
 Date Published:
 Journal Name:
 Networks and Heterogeneous Media
 Volume:
 17
 Issue:
 3
 ISSN:
 15561801
 Page Range / eLocation ID:
 427
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
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