This essay investigates the bipartite consensus over matrix-weighted hybrid multiagents signed networks using an event-triggered control method, which reduces unnecessary control updates and saves resources. Under the designed event-triggered hybrid control algorithm, using variable transformation, Gauge transformation, stability theory, and inequality techniques, the hybrid bipartite consensus criteria which are related to the matrix-weight of each edge of the signed networks, coupling gains, discrete interval, and some of the parameters of the event-triggered law are established. Furthermore, Zeno-behavior is excluded. Finally, the obtained results are illustrated via a simulation example.

In this article, we study the matrix-weighted consensus issues for second-order discrete-time multiagent systems on directed network topology. Under the designed matrix-weighted consensus algorithm, based on the eigenvalues of the Laplacian matrix, coupling gains, and discrete interval, we build some consensus conditions for reaching discrete-time consensus and deduce some simplified and straightforward consensus conditions for undirected network topology. Besides, for a given network topology, we theoretically analyze the influence of the coupling gains and discrete intervals on the consensus conditions of the network dynamics. Finally, we offer several simulation examples to validate the obtained results.

As we all know, heterogeneity is a very important feature of multiagent systems (MASs). In this article, we examine the consensus control problems of matrix-weighted hybrid MASs, which contain discrete-time and continuous-time dynamic agents. Under fixed and switched undirected networks, three consensus algorithms are proposed for matrix-weighted hybrid MASs. In the three consensus algorithms, the sampled data control method is utilized in the continuous-time subsystem to analyze the convergence of different dynamic agents in the matrix-weighted interaction mode. For the symmetric matrix-weighted fixed and switched multiagent networks, when the sampling period meets certain conditions, the consensus criteria are established via the matrix theory, Lyapunov stability theory, and analysis theory. Moreover, asymmetric matrix-weighted fixed multiagent networks which can be applied to some scenarios with scaled and rotated updates constraints are considered, and consensus criteria are also obtained when the sampling period meets certain conditions. Finally, a few simulation examples are supplied to validate the correctness of the obtained theoretical results.

The second-order scalar-weighted consensus problem of multiagent systems has been well explored. However, in some practical antagonistic interaction networks, the interdependencies of multidimensional states of the agents must be described by matrix coupling. In order to highlight the influence of matrix coupling in the antagonistic interaction network, we investigate the second-order matrix-weighted bipartite consensus problem on undirected structurally balanced signed networks. Under the proposed bipartite consensus protocol, an algebraic condition is obtained for achieving second-order bipartite consensus via utilizing matrix-valued Gauge transformation and stability theory. Then, using the obtained criteria, a more direct algebraic graph condition is given for reaching bipartite consensus. Besides, because of the existence of negative (positive) semidefinite connections, the matrix-weighted network may have clustering phenomena, which means that matrix weights play a critical role in achieving consensus. An algebraic graph condition for admitting cluster bipartite consensus is provided. By designing matrix weights in practical scenarios, the required number of clusters can be obtained. Finally, the theoretical results are verified by five simulation examples.

Advanced in unpredictability, ergodicity and sensitivity to initial conditions and parameters, chaotic maps are widely used in modern image encryption algorithms. In this study, the authors propose a novel image block encryption algorithm based on several widely used chaotic maps. In their algorithm, the image blocking method is variable, and both shuffling and substitution algorithms are adopted based on different chaotic maps. Several simulations are provided to evaluate the performances of this encryption scheme. The results demonstrate that the proposed algorithm is with high security level and fast encryption speed, which can be competitive with some other recently proposed image encryption algorithms.

Pseudorandom binary sequences play a significant role in many fields, such as error control coding, spread spectrum communications, and cryptography. In recent years, chaotic system is regarded as an important pseudorandom source in the design of pseudorandom bit generators (PRBGs). Among them, most are based on one or more fixed chaotic systems, and the generated binary sequences come to be stationary. However, these kinds of chaotic PRBGs can be attacked by reconstructing the phase space or using some statistical analysis methods. In this study, a scheme for chaotic PRBG based on non‐stationary logistic map is proposed. The authors design a dynamic algorithm to change the driven parameter sequence (not random) into a random‐like sequence. The variable parameters disrupt the phase space of the system, which can resist the phase space reconstruction attacks effectively. They prove that the non‐stationary logistic map is still chaotic under Wiggins’ chaos definition. The numerical analysis shows that the generated binary sequences have good cryptographic properties and can pass the well‐known statistical tests. The authors’ chaotic PRBG based on non‐stationary logistic map is a novel scheme in the design of PRBG, and is more secure than the PRBGs based on fixed chaotic systems.

In this study, the authors use a non‐symmetric partition to generate N ‐phase pseudorandom sequences using the logistic maps. The theoretical analysis shows that this N ‐phase logistic sequence is with uniform distribution, as well as independent and identically distributed. Numerical experiments show that these N ‐phase logistic sequences have high complexity and are with good randomness. A fast algorithm with its time complexity be O ( M ) is proposed to generate these N ‐phase sequences. Furthermore, they propose a new image encryption algorithm based on the N ‐phase logistic sequence, which is combined with both shuffling and substitution algorithms. Several security tests are carried out to demonstrate that the authors’ new algorithm is with a high security level, and can resist various attacks, which can be competitive with some other recently proposed image encryption algorithms.