Transport of the overdamped Brownian particles in an asymmetric periodic potential is investigated in the presence of ac driving forces and time-delayed feedback. Using Brownian dynamics simulations, we obtain the average velocity of the particles. We found that it is possible to enhance the average velocity remarkably through increasing the delay time. For a large value of the delay time, the average velocity becomes independent of the delay time. Especially, for small values of noise intensity, there exists a threshold value of noise intensity below which no directed transport can be obtained. We can also observe current reversals by changing the parameters.

The transport of overdamped Brownian particles in an asymmetric periodic potential was investigated in the presence of temporally asymmetric correlated two-state noise and a load. It was found that the interplay between temporal asymmetry and spatial asymmetry can bring about some peculiar phenomena. A reversal of the current will occur when the parameters are suitably chosen. A value of the potential height exists at which the current takes its maximal value. For very large values of the correlated time, the variation of the current is independent of the correlated time. Remarkably, we also observed that the correlated time cannot affect the value of the load at which the current reverses its direction.