RESUMEN
In this paper, we study the problem of output feedback distributed containment control for a class of high-order nonlinear multiagent systems under a fixed undirected graph and a fixed directed graph, respectively. Only the output signals of the systems can be measured. The novel reduced order dynamic gain observer is constructed to estimate the unmeasured state variables of the system with the less conservative condition on nonlinear terms than traditional Lipschitz one. Via the backstepping method, output feedback distributed nonlinear controllers for the followers are designed. By means of the novel first virtual controllers, we separate the estimated state variables of different agents from each other. Consequently, the designed controllers show independence on the estimated state variables of neighbors except outputs information, and the dynamics of each agent can be greatly different, which make the design method have a wider class of applications. Finally, a numerical simulation is presented to illustrate the effectiveness of the proposed method.
RESUMEN
This paper considers the distributed consensus tracking problem for a class of high-order stochastic multiagent systems with uncertain nonlinear functions under a fixed undirected graph. Through the recursive method, the novel nonlinear distributed controllers are designed. By constructing a kind of special form for the virtual controller in the first step of recursive design, we realize that the state variables of every agent are separated except the outputs of the adjacency agents. The designed controller of each agent only depends on its own state variables and the outputs of the adjacent multiagents. With the proposed method, it is not required any more that the orders of the agents are same. This makes the designed controller be easier to be implemented and the proposed method be applicable for a wider class of multiagent systems. The efficiency of the design approach is illustrated by a simulation example.
RESUMEN
Objective:To discuss the diagnosis, treatment and outcome of patients with gliomatosis cerebri (GC). Methods:Retrospectively reviewed the clinical manifestations and radiological appearances of 6 patients with GC, which were diagnosed in our hospital between 1993 and 2003. We employed surgical treatment in three patients, stereotactic biopsy in two, and the other one received both biopsy and surgery. Results: The lesions of GC infiltrated more than two lobes in brain. CT studies showed diffuse hypodensity changes and enhancement was absent in four patients. MRI examinations revealed isointense or hypointense regions on T1WI, and uniformly high signal on T2WI. MRI also disclosed structural enlargement. All patients received radiotherapy after surgery and three patients underwent chemotherapy additionally. Five patients died during follow up with average course of 16.4 months. Conclusion:MRI examination is valuable in the diagnosis and the prognosis of GC is poor.
