Adaptive Agent Digraph And Its Application On Brittleness Analysis Of Complex System

Adaptive agent digraph based on the complex adaptive theory and digraph theory has been initiated in this paper. It is an intelligent digraph, whose vertex has adaptability. The adaptive digraph's vertex is as well as an adaptive agent in complex adaptive system. It could store knowledge, study by influencing each other and exchanging with the environment. Adaptability is the cause of complexity.To discuss the adaptive agent digraph, the correlative definition, the dynamic equation of adaptive vertexes and the condition on stability have been proposed. Adjacency matrix of an adaptive agent digraph has been presented to express and calculate the digraph simply. Some methods have been presented to analyze the dynamic behaviors of digraph, such as stability analysis and frequency analysis. Then the adaptability of vertexes has been explored. The adaptive agent digraph based on complex adaptive system theory has the following characteristic: Adaptability, intelligence, parallelism, emergence, memory, clear visualization, good logic and it couldn't analysis a system quantitatively but analysis it qualitatively. So it is applied to study the brittleness of complex systems.Brittleness is an important character of complex systems. It is a new concept. A system can be collapse after one of its subsystems being collapse by catenulate course, that is brittleness. To prove the being of brittleness, the relation between the entropy and the collapse in a complex system has been analyzed. On this condition, the model of brittleness based on cellular automata has been established. The model is the basic model of brittleness. It can visualize the normal collapse form of complex systems clearly.Furthermore, a digraph for brittleness has been used to describe the brittle link of complex systems. Then the collapse path in the digraph has been presented to express the pipeline of collapse in a system. Ant colony algorithm is good at the TSP, so an improved ant colony algorithm has been proposed to seek for the maximal or minimal collapse path. The research on collapse path is necessary to find out the brittle source and forecast the collapse.To study the brittleness further, an adaptive agent digraph model of brittleness has been established. In the model, the adaptive vertex is the subsystems, the entropy is the flow function, flow is the medium to affect each other among subsystems, and brittle link between subsystems is arc of digraph. Then the brittle behaviors with the adaptive agent digraph model have been studied.In order to illuminate the adaptive agent digraph, the warship power network is looked as the example. The warship power network is more larges and more complex along with the development of ship, so the research on the brittleness of warship power network is important. Moreover the adaptive agent digraph model is applied to study on the brittleness of a warship power network. At first, the being of brittleness in the warship power networks has been discussed. The dynamic brittle behaviors of the warship power network have been simulated. Then using the variance analysis for different adjacency weight matrixes, the relation between adjacency weight matrix and the disorder degree of the whole network has been analyzed.The warship power network has five power distribution modes with different topological structures: feedback mode, main bus mode, mixed mode, ring mode and net mode. In the end, the five topological adaptive agent digraph models of brittleness for the five modes have been built up, and brittleness of the five modes have been analyzed and compared.