Through the analytical calculation and numerical simulation,the effects of noise parameter on the steady probabilty current are discussed in one-dimensional inertia ratchet potential.

Effects of correlated color noises on the stationary probability distribution;

The stationary probability distribution (SPD), the mean value and the normalized variance of the laser intensity of single model laser cubic model driven by a multiplicative colored noise and an additive colored noise that are cross correlated with white noise form are calculated.

In the case of small additive noise parameters, good agreement is achieved for the stationary probability distribution between the computer simulation and the approximative scheme.

When the increase rate is less than zero, effects of internal fluctuations on the stationary probability distribution of the biologic species are obvious.

The effects of colored-noise on the steady probability distribution are discussed in the linear system.

The interpolation approximation is applied to the laser system to calculate the steady probability distributions of a single mode laser.

Stationary state probabity density with two coupling colored noise;