http://hdl.handle.net/10071/5550 2026-04-09T00:09:30Z http://hdl.handle.net/10071/33086 Título próprio: Optimal control synchronization of a complex network of predator-prey systems Autoria: Silva, C. J.; Cantin, G. Editor: Bernard Bonnard; Monique Chyba; David Holcman; Emmanuel Trélat Resumo: In this work, we consider a complex network of predator-prey systems, modeling the ecological dynamics of interacting species living in a fragmented environment. We consider non-identical instances of a Lotka-Volterra model with Holling type II functional response. We study optimal control problems, for the minimization of the default of synchronization in the complex network, where the controls reproduce the implementation of ecological corridors. The main goal is to restore biodiversity of life species in a heterogeneous habitat by reaching at least a global coexistence equilibrium, or in a better scenario, a global limit cycle which would guarantee biological oscillations, which means rich life dynamics. 2024-01-01T00:00:00Z http://hdl.handle.net/10071/7523 Título próprio: Social and political events and chaos theory - the "drop of honey effect" Autoria: Filipe, José António; Ferreira, Manuel Alberto M. Resumo: The applications of chaos theory began first by natural sciences and then follow to the humanities and social sciences. Since the beginning got rapidly a developing field. Chaos is extremely complex and difficult to be identified in the real life. But using the available information, it is possible, anyway, up to a certain extent, to find specific mathematical relationships for problems to be solved. In this work some issues are presented in order to consider this subject in the humanities and social sciences fields 2013-01-01T00:00:00Z http://hdl.handle.net/10071/7522 Título próprio: An infinite servers queue systems with poisson and non poisson arrivals busy period simulation Autoria: Ferreira, Manuel Alberto M.; Andrade, Marina Resumo: Many interesting parameters in queue theory study either have not theoretical results or, existing, are mathematically intractable what makes their utility very scarce. In this case a possible issue is to use simulation methods in order to get more useful results. In this paper this procedure is followed to learn something more about quantities of interest for those infinite servers queue systems, in particular about busy period parameters and probability distributions. A fortran program to simulate the operation of infinite servers’ queues is presented in this work. Poisson arrivals processes are considered but not only. 2013-01-01T00:00:00Z http://hdl.handle.net/10071/7521 Título próprio: The Hahn-Banach theorem for the normed spaces Autoria: Ferreira, Manuel Alberto M. Resumo: It is intended, in this chapter, to present the Hahn-Banach theorem in its version for the normed spaces. This result is particularly important in optimization problems because of the separation theorems consequences of it. 2013-01-01T00:00:00Z