We consider a two-competitor/one-prey model in which both competitors exhibit a general functional response and one of the competitors exhibits a density-dependent mortality rate. It is shown that the two competitors can coexist upon the single prey. As an example, we consider a two-competitor/one-prey model with a Holling II functional response. Our results demonstrate that density-dependent m...

It has been established by now that the problem of the absolute stability originates from a paper of B.V. Bulgakov published in 1942. The engineering application generating the problem was the so called gyroscopic pendulum, with various applications in stabilization of ships, aircrafts or armored cars. Even if nowadays the technical implementation of this device might be completely different, t...

This article presents an unified way to design neural networks characterized as second order ordinary differential equations (ODE), that aim to find the global minimum of nonconvex scalar functions. These neural networks, alternative referred to as continuous time algorithms, are interpreted as dynamical closed loop control systems. The design is based on the control Liapunov function (CLF) met...

In this paper, we review analytical methods for a rigorous study of the existence and stability of stationary, multiple spots for reaction-diffusion systems. We will consider two classes of reaction-diffusion systems: activator-inhibitor systems (such as the Gierer-Meinhardt system) and activator-substrate systems (such as the Gray-Scott system or the Schnakenberg model). The main ideas are pre...

The existence of positive equilibrium solutions of the McKendrick equations for the dynamics of an age-structured population is studied as a bifurcation phenomenon using the inherent net reproductive rate n as a bifurcation parameter. The local existence and uniqueness of a branch of positive equilibria which bifurcates from the trivial (identically zero) solution at the critical value n = 1 ar...

We consider a communications network consisting of many mobiles. There are random external data processes arriving at some of the mobiles, each destined for a unique destination or set of destinations. Each mobile can serve as a node in the possibly multi-hop (and not necessarily unique) path from source to destination. At each mobile the data is queued according to the source-destination pair....

We consider the problem of characterizing those systems which admit (weak) Liapunov functions with nice analytic properties. Our investigation gives a rather complete picture of the situation for the one-dimensional case.

A Liapunov type stability theory for high order systems of differential equations is developed. This is done by reduction to the classical case, using the theory of polynomial models.