Lower-dimensional simple chaotic systems with spectacular features

Lower-dimensional chaotic systems are easily implementable and cost-effective, therefore, more desirable for practical considerations. Not only can such systems preserve basic chaotic properties, but they may also possess some special features that are beneficial for real applications, such as simple mathematical equations, various types of equilibria, symmetry, conservativity, multi-stability, hidden and multi-scroll attractors, and even hyper -chaotic dynamics. This paper presents a brief review of lower-dimensional chaotic systems with unusual complex characteristics, offering a handy reference for future research on chaotic systems.