In recent years, the well-developed Vicsek model has attracted more and more attention. Unfortunately, in-depth research on its convergence speed is not yet completed. In this paper, we investigate some key factors governing the convergence speed of the Vicsek model with the assistance of...

The synchronization of fractional-order hyperchaotic systems is studied, using the Rössler system as an example. Based on the Laplace transformation theory, sufficient conditions for global synchronization of the systems are given analytically. Also, the variational iteration method is...

Drought is one of the major natural disasters occurring in China and causes severe impacts on agricultural production and food security. Therefore, agricultural drought vulnerability assessment has an important significance for reducing regional agricultural drought losses and drought disaster...