Research On The Key Technology Of The Invulnerability Of Complex Information System Network

The complex information system network has the characteristics of complex hierarchical association,interleaving of communication links,and dynamic network changes.Once the complex information system network is destroyed,the entire complex information system will be paralyzed.Therefore,studying the key technology of complex information system network invulnerability and improving the network invulnerability will become very important.At present,the research on the invulnerability of complex information system networks has also achieved some results,but it still faces many key scientific issues and technical challenges that need to be resolved.This dissertation mainly focuses on the three types of challenges in the structure of complex information system networks,such as structural invulnerability evaluation,hierarchical load distribution control,and access control reconfiguration.On the basis of analyzing the existing methods and research results,we will carry out research work on key technologies such as the invulnerability evaluation,invulnerability control,and invulnerability Reconfiguration of complex information system networks.The specific research contents and innovation points are summarized as follows.(1)Research the complex information systems network invulnerability evaluation model based on invulnerability entropy.For most existing complex information systems,network invulnerability measurements are mostly deterministic,and it is difficult to meet the needs of dynamic evolution of network and invulnerable evaluation of small-degree nodes.An invulnerable evaluation model of complex information systems based on network-structural-entropy measurement is proposed.Firstly,the typical network invulnerability measurement of complex information system is analyzed.Secondly,the edge importance evaluation method for degrees and betweenness is not considered the effect of the interconnection between the neighbor nodes of the two endpoints on the edge importance,the key edge identification method and edge critical definition method based on bridge coefficient are proposed.Thirdly,node critical degree of level flow betweenness and edge critical degree based on bridge coefficient are adopted,the evaluation model of invulnerability entropy measurement of complex information system network based on node key and edge key are proposed.The simulation verifies that the invulnerability entropy measurement has strong sensitivity and high precision,and can be used to better evaluate the invulnerability performance of a complex information system network.(2)Study the network load distribution invulnerability control method for complex information system.For the existing cascading failure model,the initial load definition can neither accurately reflect the characteristics of the hierarchy or the importance of the nodes,nor can it solve the problem of load redistribution with the hierarchical characteristic network.This paper proposes a non-uniform adjustable load redistribution control method of complex information system network.Firstly,based on the deficiency of the definition of the initial load of a single-level and single-node network,combined with the hierarchical and criticality characteristics of the complex information system network,a hierarchical-entropy-based initial load definition method for complex information system network is proposed.Secondly,aiming at the problem that low-level nodes can not bear the load of high-level nodes,a method of re-distribution of cascading failure load of complex information system network with non-uniform adjustable load is proposed.The simulation results show that the cascading invulnerability of the complex information system network can be optimized by adjusting the initial load adjustment coefficient,tolerance parameter,and load redistribution level coefficient.This method effectively suppresses the propagation of cascading failures,reduces the number of failed nodes,and improves the cascading failure control capability of complex information systems networks.(3)Study the network Reconfiguration and switching invulnerability Reconfiguration methods of complex information system networks.Firstly,the existing network Reconfiguration method does not comprehensively consider the node criticality,edge criticality and network hierarchy,so that the network invulnerability performance is poor.A hierarchical-entropy-based complex information system network Reconfiguration method is proposed.The algorithm simulation based on different repair probability,adjustable coefficient and different Reconfiguration methods is designed.The simulation results show that the algorithm reduces the cost of network Reconfiguration and satisfies the needs of the complex information system network for different Reconfiguration methods such as upgrade,leapfrog,transfer and combination,and also takes into account the system invulnerability requirements.Secondly,aiming at the existing multi-attribute vertical handover algorithm without considering the switching requirements of different service features and different user preferences,an improved algorithm based on fuzzy multi-attribute vertical switching is proposed.We analyzed the fuzzy multi-attribute vertical switching improved algorithm and its flow,and designed the algorithm simulation based on different service features such as voice,text,image and interactive information and different user preferences.The results of several simulation indicators,such as average outage probability,new call blocking rate,switching blocking rate and average switching rate,show that the switching method significantly improves the network invulnerability performance and better meets the business switching needs of different mobile terminals for the complex information system network.