Isoscalar and isovector monopole oscillations that correspond to giant resonances in spherical nuclei are described in the framework of time-dependent relativistic mean-field theory. Time-dependent and self-consistent calculations that reproduce experimental data on monopole resonances in Pb show that the motion of the collective coordinate is regular for isoscalar oscillations, and that it bec...

We consider hidden Markov processes in discrete time with a finite state space X and a general observation or read-out space Y , which is assumed to be a Polish space. It is well-known that in the statistical analysis of HMMs the so-called predictive filter plays a fundamental role. A useful result establishing the exponential stability of the predictive filter with respect to perturbations of ...

With the significant development in communication systems especially in the public channels through which our information travels, there are more increasing in the channels problems. The information security is the important one that should be enhanced. This paper presents a chaos-based speech scrambling system. Chaotic maps have been successfully used for large-scale data encryption such as im...

This paper presents a strategy for finding optimal controls of nonlinear systems subject to random excitations. The method is capable to generate global control solutions when state and control constraints are present. The solution is global in the sense that controls for all initial conditions in a region of the state space are obtained. The approach is based on the Bellman’s Principle of opti...

We study a system containing many particles of identical kinematics with a zero range interaction that scatters one from the other, and with the possible exchange of an attribute. Taking an initial condition in which the attribute is asymmetrically distributed in the regions of momentum space occupied by the particles, we study the rate at which it becomes uniformly distributed, through collisi...

Abstract We study the existence and uniqueness of solutions of ∂tu − ∆u + u q = 0 (q > 1) in Ω×(0,∞) where Ω ⊂ R is a domain with a compact boundary, subject to the conditions u = f ≥ 0 on ∂Ω× (0,∞) and the initial condition limt→0 u(x, t) = ∞. By means of Brezis’ theory of maximal monotone operators in Hilbert spaces, we construct a minimal solution when f = 0, whatever is the regularity of th...

We propose two new, fast and stable methods to estimate time series models written in their equivalent state-space form. They are useful both, to obtain adequate initial conditions for a maximumlikelihood iteration, or to provide final estimates when maximumlikelihood is considered inadequate or computationally expensive. The state-space foundation of these procedures provides flexibility, as t...

In this work, probabilistic reachability over a finite horizon is investigated for a class of discrete time stochastic hybrid systems with control inputs. A suitable embedding of the reachability problem in a stochastic control framework reveals that it is amenable to two complementary interpretations, leading to dual algorithms for reachability computations. In particular, the set of initial c...

A relatively optimal control is a stabilizing controller that, without initialization nor feedforwarding and tracking the optimal trajectory, produces the optimal (constrained) behavior for the nominal initial condition of the plant. In a previous work, a linear dynamic relatively optimal control, for discrete–time linear systems, was presented. Here a static solution is shown, namely a dead–be...

in this paper,  a heuristic algorithm is proposed in order to solve a nonlinear lexicography goal programming (nlgp) by using an efficient initial point. some numerical experiments showed that the search quality by the proposed heuristic in a multiple objectives problem depends on the initial point features, so in the proposed approach the initial point is retrieved by data envelopment analysis...