This paper is concerned with the synchronization control problem for a class of discrete time-delay complex dynamical networks under a dynamic event-triggered mechanism. For the efficiency of energy utilization, we make the first attempt to introduce a dynamic event-triggering strategy into the design of synchronization controllers for complex dynamical networks. A new discrete-time version of the dynamic event-triggering mechanism is proposed in terms of the absolute errors between control input updates. By constructing an appropriate Lyapunov functional, the dynamics of each network node combined with the introduced event-triggering mechanism are first analyzed, and a sufficient condition is then provided under which the synchronization error dynamics is exponentially ultimately bounded. Subsequently, a set of the desired synchronization controllers is designed by solving a matrix inequality. Finally, a simulation example is provided to verify the effectiveness of the proposed dynamic event-triggered synchronization control scheme.

Scale Invariant Feature Transform (SIFT) proposed by Lowe has been widely and successfully applied to object detection and recognition. However, the representation ability of SIFT features in face recognition has rarely been investigated systematically. In this paper, we proposed to use the person-specific SIFT features and a simple nonstatistical matching strategy combined with local and global similarity on key-points clusters to solve face recognition problems. Large scale experiments on FERET and CAS-PEAL face databases using only one training sample per person have been carried out to compare it with other non person-specific features such as Gabor wavelet feature and Local Binary Pattern feature. The experimental results demonstrate the robustness of SIFT features to expression, accessory and pose variations.

In [9] Kaimanovich introduced the concept of augmented tree on the symbolic space of a self-similar set. It is hyperbolic in the sense of Gromov, and it was shown in [13] that under the open set condition, a self-similar set can be identified with the hyperbolic boundary of the tree. In the paper, we investigate in detail a class of simple augmented trees and the Lipschitz equivalence of such trees. The main purpose is to use this to study the Lipschitz equivalence problem of the totally disconnected self-similar sets which has been undergoing some extensive development recently.Comment: Advances in Mathematics, accepted (2012). 29 pages, 10 figure

The autonomous obstacle avoidance planning of USV is the guarantee and the precondition of carrying out the performance. Obstacle avoidance planning is required to possess high accuracy and instantaneity due to a complex environment and faster speed. The algorithm of Artificial Potential Field has the advantage of sample mathematical model, which is easy to understand and implement, and facilitate the underlying control. However, application of traditional Artificial Potential Field has the problems of local minimum, destination unreachable, and poor accuracy of algorithm. Aiming at these issues, a method of the obstacle avoidance planning of Unmanned Surface Vehicle based on improved Artificial Potential Field is proposed in this article, and its feasibility is demonstrated using MATLAB simulation.