Research On State Diagnosing And Reliability Assessment Model Of Subhealth Network System

With the quick development of modern computer communication technology,the network system is gradually large-scale to turn,continuously to turn,highly speed turns and automates.The function is more and more ,the structure is also more and more complicated.and its malfunction diagnoses and prognosis technologies invole some factors and levels of mutual restraint and interrelation,some of these factors are not fatal for the system running,but once have faults,the network system is in the state between normal state and malfunction,which is called subhealth state.during this state,there may be a great financial loss if the network system stops running and accepts maintaining.there may be lead to unpredictable damage if the network system is still running under any maitaining.So,state diagnosing and reliability generalized assessment model of subhealthy network system is the urgently needed solution key question.During this background ,with the support of the national natural science fund item"the diagnosing prediction and of subhealty complicated system (No.61004118)"and the innovation fund item of Chongqing Jiaotong University"state diagnosing and intelligent maintenance decision-making mechanism of subhealth network system(No.0904)",the thesis make the more detailed study around the key problem that research on state diagnosing and reliability assessment model of subhealth network system.The main research results include:1. The detailed procedure of network system's fault management and the feature of network system's fault are reviewed, the merits and demerits and proper scope of network system's fault location methods and intelligent fault diagnosis methods are profoundly anatomised.2. In view of the present exsitence"subhealth"state of network system,based on deeply discussing the affects that affect the network system performance degradation, combining the"subhealth"characteristic and the relation between internal nodes of network system,using the differential equation in math,giving the corresponding algorithm rules,a kind of performance degradation evaluation model in the"subhealth"state of network system is proposed, and by the example analysis shows that the model can good forecast "subhealth" network system transform rule of future possibilities.3. After studying the advantages and disadvantages of network system's common reliability analysis methods,a kind of network reliability evaluation model based on the information entropy theory was proposed.First,building reliability prediction model of network system using the concept of channel capacity from the perspective;Then,solved the maximum of network link faliure's probability'sum and the corresponding node link failure's probability during the conditions that giving a node reliability and distribution of connection probability; Finally, olved the maximum of network link faliure's probability'sum and the corresponding node link failure's probability during the conditions that giving a node reliability.The theoretical analysis shows that the constructed model is effective and reasonable.In the finally part, the summary to the research work of the full text is given,and the direction of further study is pointed out that research on state diagnosing and reliability assessment model of subhealth network system.