Zhaodi Xu

Control design based on state observer for nonlinear delay systems

This paper is concerned with the problem of feedback control based on state observer for a class of nonlinear delay systems. The purpose was to design a state observer and dynamic output feedback controller such that the closed-loop system is asymptotically stable. A linear matrix inequality (LMI) approach is developed to solve this problem. Finally, a numerical example is presented to illustrate the results given in this paper and simulation shows that the method is very effective.

A method of constructing Kirkman triple system of higher order

A method of construction Kirkman triple system of higher order is proposed. A foundamental theory of constructing Kirkman triple system of order r×t is described.The entire procedure of construction Kirkman triple system of order 225 is presented.

Wavelet neural network predication for epidemic outbreak

In order to predict the epidemic outbreak, this paper presented a wavelet neural network method. The wavelet neural network designing theory framework was also provided: wavelet function is used as activation function in recessive layer, the connection weights are decided by wavelet function coefficients. Finally, the presented method efficiency and feasibility were discussed by a simulation example, some key problems and research directions also summarized..

A new method of constructing Steiner triple systems

A new method of constructing Steiner triple systems has been proposed. The basic theory that contain definition, lemmas of decomposable of some complete graphs has been described. A theorem concerning construction of Steiner triple systems has been proved. The entire procedure of constructing Steiner triple systems of order 91 has been presented.

H-infinite output tracking control for neutral systems with time-varying delay and nonlinear perturbations: An LMI approach

In this paper, the problem of H °° output tracking control for liner neutral systems with time-varying and nonlinear perturbations is investigated. The purpose of this paper is to establish a delay-dependent sufficient condition to guarantee H°° output tracking performance and obtain a less conservative result. A liner matrix inequality (LMI) approach is adopted to solve the problem. Finally, a numerical example shows that the method is very effective.

A delay-dividing approach to stability criteria for neutral system with time-varying delay

This paper studies delay-dependent robust stability criteria problem for neutral system with time-varying delay. Based on a new class of Lyapunov functional approach and linear matrix inequality technology, a new delay dependent stability criterion for neutral system is derived by employing a delay-dividing approach. Finally, numerical examples are given to demonstrate the derived conditions are effectiveness and much less conservative than those given in the literature.

New stability criteria for neutral systems with interval time-varying delays and nonlinear perturbations

This paper concerns the problem of the asymptotic stability problem for neutral system with interval time-varying delays and two classes of uncertainties. Based on the Lyapunov method, a sufficient delay-dependent criterion for asymptotic stability is derived in terms of linear matrix inequality (LMI). Slack variables and convex combination technique are adopted to reduce the conservatism of obtained results. A numerical example is given to show the effectiveness of proposed method.

New method of constructing triple system with order s×t

The method of constructing triple system with order s×t is proposed. The fundamental theory of constructing triple system with order s×t is described and the conclusion is proved. The process of construction triple system with order 7×7 is proposed in detail. The conclusion suggested that the fundamental theory of constructing triple system which provided a new and effective ways for constructing triple system of order 7×7.

Novel Robust Stability Criteria for Neutral Systems with Interval Time-Varying Delays and Nonlinear Perturbations

This paper considers the robust stability for a class of linear neutral systems with interval time-varying delay and nonlinear perturbations. A Lyapunov Krasovskii functional, which takes the range information of the time-varying delay into account, is proposed to analyze the stability. A novel approach is established for estimating the upper bound on the time derivative of the Lyapunov Krasovskii functional, and by utilizing free weighting matrices, new delay-range-dependent stability criteria are introduced in terms of linear matrix inequalities. Numerical examples are given to show the effectiveness of the proposed approach.

A new method of constructing Kirkman triple system

The method of constructing Kirkman triple system with order 6n+3 is proposed. The fundamental theory of constructing Kirkman triple system with order 6n+3 is described and the conclusion is proved. The process of construction Kirkman triple system with order 27 and 45 are proposed in detail. The conclusion suggested that the fundamental theory of constructing Kirkman triple system which provided a new and effective ways for constructing Kirkman triple system of order 6n+3.