We consider link error or physical channel error in wireless networks and propose a new rate- based congestion control scheme for wireless networks, which is based on the NUM framework developed for TCP-like congestion control model in wired networks. This scheme is distributed and can be implemented by changing the number of connections opened by one user and requires no modification to either the network infrastructure, or the network protocols. The scheme is proved to be global stability in the absence of round trip delay of each user and all trajectories can converge to the unique equilibrium point. The convergence rate is also studied and stochastic disturbance is analyzed. Furthermore, a sufficient condition is obtained under which the scheme is locally stable at the equilibrium point in the presence of delay based on the general Nyquist criterion of stability.

We consider uniqueness of positive radial solutions to the system.

This paper analyzed the anti-synchronization of the four-dimensional autonomous different structural hyperchaotic systems, and achieved the anti-synchronization of the hyperchaotic Lorenz-Chen system, hyperchaotic Chen-Lü system and hyperchaotic Lü-Lorenz system with each other via the active control theory. Numerical simulations are provided for illustration and verification of the proposed method.

The original rough set model cannot be used to deal with the incomplete information systems. Nevertheless, by relaxing the indiscernibility relation to more general binary relations, many improved rough set models have been successfully applied into the incomplete information systems for knowledge acquisition. This article presents an explorative research focusing on the transition from incomplete decision system to a more complex system---the incomplete ordered decision system. In such incomplete decision system, all attributes have preference-ordered domains. With introduction of the concept of approximate distribution reduct into the incomplete ordered decision system, four new notions of approximate distribution reduct are proposed. They are the minimal subsets of condition attributes, which preserve lower and upper approximations of all upward unions and downward unions of the decision classes respectively. The judgment theorems and discernibility matrices associated with these approximate distribution reducts are also obtained. For further illustration, an example is analyzed. The research is meaningful both in the theory and in applications for the acquisition of rules in complex information systems.

Runge-Kutta discontinuous Galerkin (RKDG) finite element method for hyperbolic conservation laws is a high order method, which can handle complicated geometries flexibly and treat boundary conditions easily. In this paper, we propose a new numerical method for treating interface using the advantages of RKDG finite element method. We use level set method to track the moving interface. In every time step, a Riemann problem at the interface is defined. The two cells adjacent to the interface are computed using the Riemann problem solver. If the interface crosses a cell in the next time step, the values of the flow variables of the cell crossed are modified through linear interpolation. Othewise, we do nothing.