Research On EPC General Contracting Risk Management Of Railway Engineering From The Perspective Of Knowledge Ontology

As a key infrastructure project to promote the development of the national economy,railway engineering has the characteristics of large investment quota,complicated technology,long construction period,numerous professional and process interfaces,and great influence from the natural environment.It is a complex system engineering.The traditional railway engineering project design and construction services have been separated.The railway engineering design enterprises and construction enterprises have bidding to participate in the corresponding bidding tasks.The participants in the project have problems such as poor communication,isolated information,and difficult to timely feedback of project changes.The risk management of the general contracting project of EPC(Engineering Procurement Construction(EPC)is adopted.Compared with the traditional construction general contracting,the general contractor also has to bear various risks such as engineering design and material equipment procurement,which makes the risk types and factors more.Diverse and complex.In order to effectively prevent and control engineering risks,reduce unnecessary losses,and ensure that the main objectives of project management are expected.The article attempts to introduce the knowledge ontology theory into the risk management of EPC general contracting project of railway engineering,and provides new ideas for the new EPC general contracting risk response of railway engineering.Specific content includes:(1)RBS-based railway engineering EPC general contracting project risk factor system identification.By comparing different EPC project risk management methods,the advantages and disadvantages and application scope of different identification methods are compiled,and the RBS risk identification method and process are determined.The risk of railway engineering EPC general contracting project is identified and risk is established.The decomposition structure and the n-dimensionalRBS risk matrix are used to classify and express the risk of the EPC general contracting project of the railway project,calculate the probability of occurrence of each risk,obtain the risk identification result,and collect statistics on the multi-level risk,and finally analyze the recognition result.The system identification method of risk factors for railway engineering EPC general contracting project that can make up for the lack of traditional risk response methods has been formed,and the basic work for further research on the knowledge ontology construction of EPC general contracting project risk of railway engineering has been made.(2)The model construction of risk analysis of the railway project EPC general contracting complex project based on the Knowledge Ontology.Firstly,we will acquire the knowledge of EPC general contracting risk of railway engineering,and classify and define the related concepts according to semantic network and XML.Then,using protégé 4.3 software,combined with the basic information of risk knowledge of EPC general contracting project of railway engineering,we will construct the risk Knowledge Ontology and carry out the consistency test.(3)Risk diagnosis model of railway engineering EPC general contracting project based on risk knowledge ontology Bayesian network.On the basis of the risk Knowledge Ontology,we will propose the rules of the transformation of the risk Knowledge Ontology to the Bayesian network,and realize the transformation from the concept to the node,and from relations to arc and the attribute value.In this dissertation,we focus on the non-complete information in the Bayesian network parameter learning algorithm,and propose the data diffusion method with the improved maximum information theory to improve the accuracy of Bayesian network conditional probability table construction.In dealing with the complex Bayesian network,it is proposed to use the message propagation search algorithm to approximately diagnose the risk of EPC general contracting of railway engineering.(4)Case-based reasoning based on risk knowledge Bayesian network,using grey correlation degree to improve rough set to identify key attributes.This dissertation analyzes the basic process of risk control measures in the EPC general contracting project of railway engineering,improves the rough set theory with gray relational degree,determines the attribute weight of the risk case of EPC general contracting project of railway engineering,and reduces the redundant attribute.By calculating the comprehensive similarity of EPC general contracting risk cases,it willstart case matching,retrieve the source cases with the largest similarity,and carry out the new railway engineering risk control by taking the reference of the risk control measures of the original case.(5)Take the EPC general contracting project of a railway project as an example,it is to verify the rationality of the risk diagnosis model and the case reasoning model,and to put forward specific suggestions and countermeasures for the project.On the basis of the previous theoretical research,the RBS method is used to identify the risk factors of the case and construct the corresponding Knowledge Ontology.The Bayesian network is used to train the probability relationship between risk factors and risk signs.On this basis,we will put forward the similarity risk case reasoning and the corresponding risk control suggestions and countermeasures to achieve the purpose of pre-control based on the detected risk factors and the diagnosed risk events.The EPC general contract project risk management research based on the Knowledge Ontology,has transformed the causal relationship between risk factors and risk events through the Bayesian network diagnosis,realized depth integration of Bayesian network and case reasoning,and the advanced control of EPC general contract project risk;it is helpful to avoid risks of the railway project EPC general contracting project and reduce the risk of loss,to make up for the current railway project management risk control.We will design and develop risk management system platform of the railway project EPC general contracting project based on the Knowledge Ontology to achieve the storage and reuse of the risk management knowledge,and provide a reference for the railway project EPC general contracting project risk management.