Papers by Keyword: Chaotic Theory

Abstract: It is difficult to detect and judge a weak electric shock signals in the leakage current accurate in the low-voltage power grid .A novel chaotic detection of the electric shock current and Lyapunov exponent is introduced in this paper .Electric shock current component is extracted according to the characteristics that chaotic system’s bifurcation action from chaotic state is sensitive to the weak signals and immune to noise .The largest Lyapunov exponent is proposed as the judgment criterion of phase transition of chaotic system. It can automatically recognize the critical state before and after electric shock.

Abstract: A novel composite framework of Cuckoo Search (CS) and Particle Swarm Optimization (PSO) algorithm called CS-PSO is proposed in this paper. In CS-PSO, initialization is substituted by chaotic system, and then Cuckoo shares optimums in the global best solutions pool with particles in PSO to improve parallel cooperation and social interaction. Furthermore, Cloud Model, famous for its outstanding characteristics of the process of transforming qualitative concepts to a set of quantitative numerical values, is adopted to exploit the surrounding of the local solutions obtained from the global best solution pool. Benchmark test results show that, CS-PSO can converge to the global optimum solution rapidly and accurately, compared with other algorithms, especially in high dimensional problems.

Abstract: For realizing highly accuracy load forecasting, a new method is proposed. Power load time series belongs to chaotic series. Firstly, for obtaining three parameters in chaotic theory, namely time delay, embedding dimension and the number of the nearest neighbors, self-correlation function method and G-P algorithm are used to reconstruct the phase space of chaotic time series. Secondly, ant colony optimization approach is introduced to more accurately acquire forecasting reference points, considering distance and relativity of phase points evolution in this paper. Finally, GM (1, 1) Model is applied to forecast daily load data. The actual forecasting results prove that the new approach has better forecasting accuracy and convergence.

Abstract: Over the past 10 years, nonlinear dynamics and chaotic theory attracted scholars and people got a deeper understanding of chaos. There are many methods for chaos research, and the method of using topological horseshoe is an important branch of those methods. So far, this is one of the core methods with mathematical rigor for chaos research. Based on simple thinking of geometric space, topological horseshoe build a bridge for numerical and theoretical studies of complex behavior of nonlinear systems so that people can carry out a series of studies for chaotic behavior. This paper introduces the basic content of topological horseshoe theory and the application to a simple power system.

Abstract: 3D Arnold cat map can be applied in image encryption, and it has more security and better effect. However, its period is fixed. The original image will be returned to itself if iterating some times. On the basis of 3D Arnold cat map, it presented an algorithm of image encryption which separates the original image to many same blocks and no period. Simulation analysis shows that the encryption algorithm has characters of strong keys, better effect and fast.

Abstract: Arnold cat map is a classical transformation of image encryption, but it has some shortcomings such as short key quantities, small period and so on. On the basis of Arnold cat map, it presented an algorithm of image encryption based on 3D Arnold cat and chaotic map. Simulation experiments show that the encryption algorithm has characters of strong keys, better effect and fast.