Narrow Results

This paper presents a perturbation analysis of a nip contact of two paper machine rolls. The two degrees of freedom model of the system is considered. The model includes nonlinear terms of the rolling contact and a time delay term. The multi-scale method has been applied to obtain an approximate solution and limit cycle amplitudes. Some numerical results are given as well.

Graphic simulation based on virtual reality technology is applied to the tele-operation robot system with tele-presence to make full use of the immersion feeling and the forecast property of the 3-D graphic stereoscopic display, which not only provides the operator with friendly work windows but also can overcome the effect of the communication time delay in tele-operation. In order to investigate the ineluctability communication time delay in force tele-presence of the tele-operation robot system, a tele-presence system based on the virtual reality is setup in this paper. The system structure, geometrical noumenon modeling, and man-machine interface are introduced in detail. In the tele-operation system, graphical robot technology is used to solve the time delay, and the relating experiments have proved the validity of the reappearance of the movement of an actual robot by a graphical robot.

Equilibrium maintenance during quiet standing was investigated using a double pendulum model of body movement with perturbation noise. The influence of time delays on stability during instances of noise perturbation was discussed theoretically and numerically. The multi-scale method was generalized to derive the approximate stationary response of stochastic oscillatory near critical delay of deterministic system to study the effect of reflexes delay. An analysis on the mean of the stationary response revealed that the presence of time delays led to periodic vibration in parameter space, and the mean value increased as the reflexes delay increased. However, the mean square of the stationary response varied with not only the noise but also the delay. The stochastic factor was found to have no effect on stability, but it amplified diffusion of the oscillations, which could be seen from the change in shape in the figures showing stationary joint probability density and the stationary probability density.

A restart strategy with time delay is proposed to a multi-agent consensus algorithm for an approximated distributed minimax optimization. The restart strategy controls a step length of a subgradient method and resets a local clock under certain criteria in the algorithm. A synchronization protocol with time delay is introduced in the algorithm to execute the restart strategy simultaneously. A numerical example illustrates that the proposed algorithm works well particularly in high approximation ratios.

For decades the efforts toward a better understanding of the interplay between theories of gravity and quantum principles have faced a formidable obstacle: this obstacle is the difficulty of obtaining models in which the evidence of this interplay could appear at an energy scale accessible for present day experiments/observations. In the last years this perspective has changed, and one of the possibilities that has been considered is that quantum gravity effects could manifest themselves in the propagation of light that is coming from astrophysical sources. In this talk we will review in this perspective observations of a very high energy distant source by the MAGIC telescope.

In this paper, we studied a predator-prey model with delayed stage structure. By analyzing the corresponding characteristic equations, we discussed the local stability of a positive equilibrium and two boundary equilibria, respectively. By using persistence theory on infinite dimensional systems and comparison argument, we obtained the sufficient conditions for the global stability of the positive equilibrium and one of the boundary equilibria. As a result, we obtain the threshold for the permanence and extinction of the system.

In this paper, we consider the sliding mode control of delayed T-S fuzzy neural network with normbounded uncertainties. Based on the Lyapunov-Krasovskii stability theory, we originally research the sliding mode control method for T-S fuzzy neural network with time delay on the basis of the linear matrix inequalities (LMIs). A numerical example is given to validate the effectiveness of our method.

This paper deals with a five coupled Hamiltonian Duffing oscillators. By means of mathematical analysis method, some sufficient conditions are provided to guarantee the existence of a unique equilibrium point, stability and oscillation of the trivial solution for the model. Computer simulation indicated the effect of our result. The synchronization phenomenon has appeared.