Publications

On stability and bifurcation of Chen’s system

This article investigates some subtle characteristics of stability and bifurcation of the chaotic Chen’s system, based on rigorous mathematical analysis and symbolic computations.

Penalty-Function-Type Multi-Agent Approaches to Distributed Nonconvex Optimal Resource Allocation

In this paper, a class of penalty-function-type multi-agent approaches via communication networks is developed for distributed nonconvex optimal resource allocation. A penalty-function-type method is utilized to handle networked resource allocation constraints, and a multi-agent method is employed for handling global information in a distributed manner. Then, a penalty-function-type multi-agent system is constructed for a nonconvex optimal resource allocation model, and its stability with a local minimizer is proven. Further, a nonconvex optimal resource allocation model subject to "on/off" constraints is introduced. Based on an augmented Lagrangian function, another penalty-function-type multi-agent system is developed, and it is proven to be stable with a local minimizer. A numerical example with simulation in a heating, ventilation, and air conditioning system is presented to demonstrate the theoretical results.

Response of energy envelop in complex oscillator networks to external stochastic excitations

The response of energy envelop in complex nonlinear oscillator networks to stochastic excitations is studied. First, by using the stochastic averaging method for quasi-nonintegrable-Hamiltonian systems, the averaged Fokker–Planck– Kolmogorov equation governing the probability density of the Hamiltonian is established. Then, the stationary probability density of the Hamiltonian is derived, and the stationary probability density of the averaged energy as well as the statistical moments of the Hamiltonian is obtained. To that end, an illustrative example is provided with the analytical relationship between the response and the network parameters as well as the network structure. Specific solutions are presented for five representative topological structures. Throughout extensive simulations, the effects of system parameters, such as the network size, coupling strength and intensities of stochastic excitations on the response of the energy envelop of the networks, are carefully observed and analyzed.

Iterative Receiver for <inline-formula> <tex-math notation="LaTeX">$M$</tex-math></inline-formula>-ary DCSK Systems

Although the performance of a differential chaos shift keying (DCSK) system can be improved by designing appropriate channel codes, it is still a great challenge to do so for various channel models through transmitter and receiver designs, particularly with short frame length transmissions. Alternatively, to bypass the difficult task of designing a good channel code, an iterative receiver (IR) DCSK system is proposed in this paper. A soft demapper suitable for non-coherent M-ary DCSK system is presented, which can work either with or without fading amplitude information. Bit error rate (BER) performance shows its advantages over the non-IR DCSK system in different channel models. The achievable rate curves also indicate that gains relative to non-iterative DCSK system can be achieved with the iterative receiver.

Bifurcations, Exact Peakon, Periodic Peakons and Solitary Wave Solutions of the Modified Camassa–Holm Equation

For the modified Camassa–Holm equation, by using the methodologies of dynamical systems and singular traveling wave theory developed by Li and Chen [2007] to its corresponding traveling wave system, under different parameter conditions, all possible exact explicit bounded solutions (solitary wave solutions, periodic wave solutions, peakon, periodic peakons, as well as compactons) are obtained. More than 23 explicit exact parametric representations of the above-mentioned traveling wave system are presented.

Synchronization and desynchronization of complex dynamical networks: an engineering viewpoint

We study synchronization and desynchronization of a complex network of chaotic dynamical systems, in both continuous-time and discrete-time cases. With proved synchronization conditions, we illustrate network synchronization and desynchronization processes by a prototype composing of Henon maps in a scale-free network. We show that synchronization and desynchronization of such a complex dynamical network can be determined by the network topology and the maximum Lyapunov exponent of the individual chaotic nodes.

Optimization of Component Elements in Integrated Coding Systems for Green Communications: A Survey

The rapid development of the information-exchange networks accelerates the consumption of resources and energy. For future green communications, the integration of many conventional communication systems is necessary, where the optimization of the component elements in the communication integrated systems realizes energy-savings. In this paper, integrated physical-layer and cross-layer communication coding systems are reviewed, where the physical-layer design focuses on coded modulation and the cross-layer design focuses on the joint source-channel coding scheme and joint channel physical-layer network coding scheme. The characteristics of the integrated systems are analyzed using the extrinsic information transfer algorithm. Taking the re-design of the photograph low-density parity-check codes as an example, different design principles for various integrated systems are discussed, showing the necessity and significance of optimization for component elements in integrated coding systems for green communications.

Corrections to “M-Evolve: Structural-Mapping-Based Data Augmentation for Graph Classification”

Presents corrections to the above named paper.

Protograph bit-interleaved coded modulation: A bandwidth-efficient design paradigm for 6G wireless communications

Bit-interleaved coded modulation (BICM) has attracted considerable attention from the research community in the past three decades, because it can achieve desirable error performance with relatively low implementation complexity for a large number of communication and storage systems. By exploiting the iterative demapping and decoding (ID), the BICM is able to approach capacity limits of coded modulation over various channels. In recent years, protograph low-density parity-check (PLDPC) codes and their spatially-coupled (SC) variants have emerged to be a pragmatic forward-error-correction (FEC) solution for BICM systems due to their tremendous error-correction capability and simple structures, and found widespread applications such as deep-space communication, satellite communication, wireless communication, optical communication, and data storage. This article offers a comprehensive survey on the state-of-the-art development of PLDPC-BICM and its innovative SC variants over a variety of channel models, e.g., additive white Gaussian noise (AWGN) channels, fading channels, Poisson pulse position modulation (PPM) channels, and flash-memory channels. Of particular interest is code construction, constellation shaping, as well as bit-mapper design, where the receiver is formulated as a serially-concatenated decoding framework consisting of a soft-decision demapper and a belief-propagation decoder. Finally, several promising research directions are discussed, which have not been adequately addressed in the current literature.

Design of Code Pair for Protograph-LDPC Codes-Based JSCC System With Joint Shuffled Scheduling Decoding Algorithm

Although there are many studies on code optimization of the joint source-channel coding (JSCC) system based on double protograph low-density parity-check codes with the joint belief propagation (JBP) algorithm, but it is still unknown whether the source code and channel code (as a code pair) can perform well when the joint shuffled scheduling decoding (JSSD) algorithm is adopted. In this letter, two decoding threshold analysis algorithms, including joint shuffled protograph extrinsic information transfer (PEXIT) and source shuffled PEXIT algorithm, are proposed to calculate joint/source decoding thresholds for this system with the JSSD algorithm. With the proposed algorithms, it is found that the optimized code pairs for this system with the JBP algorithm may not perform well with the JSSD algorithm, implying that code pair with the JSSD algorithm needs to be redesigned. Then, a two-stage optimized framework is proposed to design the code pair for this system with the JSSD algorithm. Simulations and decoding threshold analysis both show that the proposed code pair for this system with the JSSD algorithm can obtain lower error floor and better waterfall performance than the existing code pairs.

Formation of multi-agent systems with desired orientation: a distance-based control approach

No abstract is provided for this article.

Parallel Computation of the Modified Extended Kalman Filter.

In this paper, we describe certain techniques for mapping the modified extended Kalman filter (MEKF) onto systolic array processors. First, we introduce a square-root algorithm based on the singular value decomposition (SVD) for the Kalman filter. Then, we develop a VLSI architecture of the systolic array type for its implementation. Compared with other existing square-root Kalman filtering algorithms, our new design is numerically more stable and has nicer parallel and pipelining characteristics when it is applied to the MEKF. Moreover, it achieves higher efficiency. For n-dimensional state vector estimations, the proposed architecture consists of O(3/2n 2) processing elements and completes an iteration in time O((s + 8)n), in contrast to the time complexity of O((s + 3)n 3) for a sequential implementation, where s ≈ log n.

Synchronizability of small-world networks generated from ring networks with equal-distance edge additions

This paper investigates the impact of edge-adding number m and edge-adding distance d on both synchronizability and average path length of NW small-world networks generated from ring networks via random edge-adding. It is found that the synchronizability of the network as a function of the distance d is fluctuant and there exist some d that have almost no impact on the synchronizability and may only scarcely shorten the average path length of the network. Numerical simulations on a network of Lorenz oscillators confirm the above results. This phenomenon shows that the contributions of randomly added edges to both the synchronizability and the average path length are not uniform nor monotone in building an NW small-world network with equal-distance edge additions, implying that only if appropriately adding edges when building up the NW small-word network can help enhance the synchronizability and/or reduce the average path length of the resultant network. Finally, it is shown that this NW small-world network has worse synchronizability and longer average path length, when compared with the conventional NW small-world network, with random-distance edge additions. This may be due to the fact that with equal-distance edge additions, there is only one shortcut distance for better information exchange among nodes and for shortening the average path length, while with random-distance edge additions, there exist many different distances for doing so.

Neural learning control

This paper studies neural learning control. Based on an earlier result for deterministic learning of unknown system dynamics from a stable control process, this paper provides detailed analysis on how the learned knowledge can be effectively exploited to achieve stability and improved control performance. Comparisons on neural learning control with adaptive neural control and linear control are also included. The effectiveness of the neural learning control approach is demonstrated using simulations.

Interplay between evolutionary game and network structure: the coevolution of social net, cooperation and wealth

We study the interplay between evolutionary game and network structure and show how the dynamics of the game affect the growth pattern of the network and how the evolution of the network influence the cooperative behavior in the game. Simulation results show that the payoff-based preferential attachment mechanism leads to the emergence of a scale-free structural property, $P(k)\sim k^{-γ}$. Moreover, we investigate the average path length and the assortative mixing features. The obtained results indicate that the network has small-world and positive assortative behaviors, which are consistent with the observations of some real social networks. In parallel, we found that the evolution of the underlying network structure effectively promotes the cooperation level of the game. We also investigate the wealth distribution obtained by our model, which is consistent with the Pareto law in the real observation. In addition, the analysis of the generated scale-free network structure is provided for better understanding the evolutionary dynamics of our model.

Solitary waves, periodic peakons and compactons on foliations in a Hertz chain model

For a Hertz chain model, by using the methodology of dynamical systems and singular traveling wave theory developed by Li and Chen [9] to its traveling wave system defined on a two-dimensional foliations in the three-dimensional space, under different parameter conditions, the existence of all possible bounded solutions (solitary wave solutions, periodic wave solutions, periodic peakons, and compactons) is proved. For the nonlinearity exponent $ k = \frac32, k = 2 $ and $ k = 3 $ in the model, as many as 23 exact explicit parametric representations of the above-mentioned traveling wave system are obtained.

Impact of dual media on misinformation spread in heterogeneous online social networks

Fractal-Type Dynamical Behaviors of Complex Systems

No abstract is provided for this article.