Adaptive Synchronization for Hyperchaotic Liu System

In this paper, the adaptive control design is investigated for the chaos synchronization of two identical hyperchaotic Liu systems. First, an adaptive control law with two inputs is proposed based on Lyapunov stability theory. Secondly, two other control schemes are obtained based on a further analysis of the proposed adaptive control law. Finally, numerical simulations are presented to validate the effectiveness and correctness of these results.

Heterogeneity-aware Multicore Synchronization for Intermittent Systems

Intermittent systems enable batteryless devices to operate through energy harvesting by leveraging the complementary characteristics of volatile (VM) and non-volatile memory (NVM). Unfortunately, alternate and frequent accesses to heterogeneous memories for accumulative execution across power cycles can significantly hinder computation progress. The progress impediment is mainly due to more CPU time being wasted for slow NVM accesses than for fast VM accesses. This paper explores how to leverage heterogeneous cores to mitigate the progress impediment caused by heterogeneous memories. In particular, a delegable and adaptive synchronization protocol is proposed to allow memory accesses to be delegated between cores and to dynamically adapt to diverse memory access latency. Moreover, our design guarantees task serializability across multiple cores and maintains data consistency despite frequent power failures. We integrated our design into FreeRTOS running on a Cypress device featuring heterogeneous dual cores and hybrid memories. Experimental results show that, compared to recent approaches that assume single-core intermittent systems, our design can improve computation progress at least 1.8x and even up to 33.9x by leveraging core heterogeneity.

Secure Data Transmission Based on Adaptive Chattering-Free Sliding Mode Synchronization of Unified Chaotic Systems

This paper is concerned with a novel secure data transmission design based on adaptive synchronization of master and slave unified chaotic systems. First, by introducing an augmented error state, an adaptive continuous sliding mode control (SMC) is derived to guarantee the synchronization of unified chaotic systems. Then, the secret message embedded in the master chaotic system can be transmitted from transmitter to receiver. Different from previous works using discontinuous SMC, the undesired chattering phenomenon can be fully eliminated, and it becomes possible to precisely recover the embedded secret message at the receiver. Last, an example is given to illustrate the success of secure data transmission with the continuous SMC developed in this paper.

Adaptive Synchronization of Fractional-Order Complex-Valued Chaotic Neural Networks with Time-Delay and Unknown Parameters

The purpose of this paper is to study and analyze the concept of fractional-order complex-valued chaotic networks with external bounded disturbances and uncertainties. The synchronization problem and parameter identification of fractional-order complex-valued chaotic neural networks (FOCVCNNs) with time-delay and unknown parameters are investigated. Synchronization between a driving FOCVCNN and a response FOCVCNN, as well as the identification of unknown parameters are implemented. Based on fractional complex-valued inequalities and stability theory of fractional-order chaotic complex-valued systems, the paper designs suitable adaptive controllers and complex update laws. Moreover, it scientifically estimates the uncertainties and external disturbances to establish the stability of controlled systems. The computer simulation results verify the correctness of the proposed method. Not only a new method for analyzing FOCVCNNs with time-delay and unknown complex parameters is provided, but also a sensitive decrease of the computational and analytical complexity.