The goal is to develop an inverse model capable of simultaneously estimating the parameters appearing in an air pollution model for an instantaneous point source, by using measured gas concentration data. The approach taken was to develop the inverse model as a non-linear least squares estimation problem in which the source term is estimated using measurements of pollution concentration on the ...

We have derived the quasar luminosity function assuming that the quasar activity is driven by a thermal-viscous unstable accretion disk around a supermassive black hole. The instabilities produce large amplitude, long-term variability of a single source. We take a light curve of a single source and calculate the luminosity function, from the function of time it spends at each luminosity. Convol...

Two cases of evolutionary stable strategy with periodic payoffs are studied. The first is a generalization of Uyttendaele et al. The second is prisoner's dilemma with periodic payoff. It is shown that reducing the defection payoff by a periodic term is sufficient to introduce cooperation provided that the initial fraction of cooperators is greater than 0.6.

This paper proposes a method for phase registration of a single non-parametric quasi-periodic signal. After a short-term period has been detected for each sample by normalized autocorrelation, Self Dynamic Time Warping (Self DTW) between a quasi-periodic signal and that with multiple-period shifts is applied to obtain corresponding samples of the same phase. A phase sequence is finally estimate...

Under conditions of Levinson-Smith type, we prove the existence of a τ -periodic solution for the perturbed generalized Liénard equation u′′ + φ(u, u′)u′ + ψ(u) = ω( t τ , u, u′) with periodic forcing term. Also we deduce sufficient condition for existence of a periodic solution for the equation

By using the frequency domain method, sufficient conditions which guarantee asymptotic stability of the null solution of a certain class of third order nonlinear delay differential equation are established. Furthermore, effective criteria for the existence of a bounded solution which is exponentially stable, periodic or almost periodic according as the forcing term is periodic or almost periodi...