21 citations · 34 across the 7 of their papers we have counts for
7 papers
Stability analysis and optimal control of the logistic equation
Márcia Lemos-Silva, Sandra Vaz, Delfim F. M. Torres
We consider the unexploited/exploited logistic equation and study the stability of equilibrium points through Lyapunov functions. Then, we apply first and second order optimality c…
A Lotka-Volterra type model analyzed through different techniques
Jorge Pinto, Sandra Vaz, Delfim F. M. Torres
We consider a modified Lotka-Volterra model applied to the predator-prey system that can also be applied to other areas, for instance the bank system. We show that the model is wel…
Discrete-Time System of an Intracellular Delayed HIV Model with CTL Immune Response
Sandra Vaz, Delfim F. M. Torres
In [Math. Comput. Sci. 12 (2018), no. 2, 111--127], a delayed model describing the dynamics of the Human Immunodeficiency Virus (HIV) with Cytotoxic T Lymphocytes (CTL) immune resp…
A Discrete-Time Compartmental Epidemiological Model for COVID-19 with a Case Study for Portugal
Sandra Vaz, Delfim F. M. Torres
In [Ecological Complexity 44 (2020) Art. 100885, DOI: 10.1016/j.ecocom.2020.100885] a continuous-time compartmental mathematical model for the spread of the Coronavirus disease 201…
A dynamically-consistent nonstandard finite difference scheme for the SICA model
Sandra Vaz, Delfim F. M. Torres
In this work, we derive a nonstandard finite difference scheme for the SICA (Susceptible-Infected-Chronic-AIDS) model and analyze the dynamical properties of the discretized system…
Stable weakly shadowable volume-preserving systems are volume-hyperbolic
Mario Bessa, Manseob Lee, Sandra Vaz
We prove that any C1-stably weakly shadowable volume-preserving diffeomorphism defined on a compact manifold displays a dominated splitting E + F. Moreover, both E and F are volume…