This brief presents an analytical study of synchronization in an array of coupled deterministic Boolean networks (BNs) with time delay. Two kinds of models are considered. In one model, the outputs contain time delay, while in another one, the outputs do not. One restriction in this brief is that the state delay and output delay are restricted to be equal. By referring to the algebraic representations of logical dynamics and using the techniques of semitensor product of matrices, some necessary and sufficient conditions are derived for the synchronization of delay-coupled BNs. Examples including a practical epigenetic example are given for illustration.

In this paper, we investigate the global stability of quaternion-valued neural networks (QVNNs) with time-varying delays. On one hand, in order to avoid the noncommutativity of quaternion multiplication, the QVNN is decomposed into four real-valued systems based on Hamilton rules: ij=-ji=k, jk=-kj=i, ki=-ik=j, i²=j²=k²=ijk=-1. With the Lyapunov function method, some criteria are, respectively, presented to ensure the global μ-stability and power stability of the delayed QVNN. On the other hand, by considering the noncommutativity of quaternion multiplication and time-varying delays, the QVNN is investigated directly by the techniques of the Lyapunov-Krasovskii functional and the linear matrix inequality (LMI) where quaternion self-conjugate matrices and quaternion positive definite matrices are used. Some new sufficient conditions in the form of quaternion-valued LMI are, respectively, established for the global μ-stability and exponential stability of the considered QVNN. Besides, some assumptions are presented for the two different methods, which can help to choose quaternion-valued activation functions. Finally, two numerical examples are given to show the feasibility and the effectiveness of the main results.

A novel technique is provided for the global stability analysis of Boolean control networks (BCNs) under aperiodic sampled-data control (ASDC). The sampling period is allowed to be taken from a limited number of values. Using the semitensor product of matrices, a BCN under ASDC can be converted into a switched Boolean network (BN). Here, the switched BN can only switch at sampling instants, which does not mean that the switches occur at each sampling instant. For the switched BN, we consider two cases: (i) switched BN with all stable subsystems; (ii) switched BN containing both stable subsystems and unstable subsystems. For these two cases, the techniques of switching-based Lyapunov function and the average dwell time method are used to derive sufficient conditions for global stability of BCNs under ASDC, respectively. The upper bounds of the cost function, which is defined to guarantee that the considered BCN is not only globally stabilized but also can assurance the performance at an appropriate level, ...

This paper investigates the pinning control for the disturbance decoupling problem (DDP) of Boolean networks (BNs) with disturbances. First, the solvability of DDP in BCNs is defined. Then, rank-conditions-based pinning control is proposed. Moreover, rank-conditions-based pinning state feedback controllers are designed for the DDP of BNs and the range of controllers' number is obtained. In addition, rank-conditions-based pinning output feedback controllers for the DDP of BNs are also discussed. An example is given to show the effectiveness of the obtained results.