Showing papers by "Hai Yu published in 2009"

Flocking in Multi-agent Systems with a Bounded Control Input

Abstract: Recently, the broad applications of multi-agent systems in many areas have stimulated a great deal of interests in studying coordinated control problems. Previous flocking protocols do not consider the input saturation. In this paper, we investigate the flocking problem with a bounded control input. Under the assumption that the underlying network is connected, all agents can attain the same velocity vector, and distances between the agents are stabilized. Numerical simulations are worked out to illustrate theoretical results.

An Image Encryption Scheme Based on Chaotic Maps

Abstract: In recent years, the classic encryption architecture based on chaotic map—“confusion diffusion” has been investigated. Among them, a two dimension Cat map is usually employed in confusion phase as an image can be seen as a two dimension array, meanwhile the flew of Cat map is obvious, that is the key space of it is not large enough. In the proposed encryption scheme, the Cat map is not with the fixed control parameters but a variable one during the confusion phase to enlarge the key space of the encryption scheme. Simulations are carried out with detail analyses, demonstrating the high security and efficient operation of our cryptosystem.

An image encryption scheme base on chaotic maps

Abstract: In recent years, the classic encryption architecture based on chaotic map—"confusion diffusion" has been investigated. Among them, a two dimension Cat map is usually employed in confusion phase as an image can be seen as a two dimension array, meanwhile the flew of Cat map is obvious, that is the key space of it is not large enough. In the proposed encryption scheme, the Cat map is not with the fixed control parameters but a variable one during the confusion phase to enlarge the key space of the encryption scheme. Simulations are carried out with detail analyses, demonstrating the high security and efficient operation of our cryptosystem.

A New Hyper-Chaos Generated from Chen's System via an External Periodic Perturbation

Abstract: Based on the chaos anti-control theory, a new four-dimensional autonomous hyperchaotic system is formulated by adding a periodic driving signal rsin(cos(φt)) to the second equation of the three-dimensional autonomous Chen chaotic system in this paper. The basic dynamical behavior of the new hyperchaotic system was not only demonstrated by numerical simulation, but also verified with Lyapunov exponents and bifurcation analysis. The new hyperchaotic system can be periodic, quasi-periodic, chaotic and hyperchaotic with the variation of the parameter φ. It also has broad and stable hyperchaotic region which makes the new hyperchaotic system has a good application prospect.

An Efficient Encryption Algorithm Based on Image Reconstruction

Abstract: An efficient image encryption algorithm is proposed, based on image reconstruction using some adjacent pixel characteristics. Since the permutation of sub-images composing of high 4-bits of the original image has a relatively high computational complexity, in the new scheme the permutation of sub-images is performed with low 4-bits instead, which therefore has a lower computational complexity. Experiment has been carried out, showing relatively high efficiency and security of the new cryptosystem.

Research and Implementation of Embedded Intelligent Network Self-Healing Equipment Based on E1 Link

Abstract: An intelligent network self-healing solution with regard to the current problem existing in the dedicated network was proposed in this paper The solution can implement the self-healing by introducing intelligent network self-healing devices which were developed and produced on our own between outside and inside networks, without changing of the current network structure The devices enable the 1 + 1 hot backup of links and also possess functions such as malfunction supervision, localization, automatic processing, etc