Abstract
In this work, based on the signed graph theory, the model of quaternion-valued neural networks (QVNNs) with cooperative-competitive interaction is established. Based on the quaternion-valued signum function and some properties, a direct analytical method without separation is proposed and quaternion-valued control schemes are developed to investigate fixed-time bipartite synchronization (FXTBS) and prescribed-time bipartite synchronization (PTBS) of QVNNs. Lastly, simulation is performed to manifest the correctness of the theorems.