Research On Risk Assessment Of City Gas Pipeline Based On Unascertained Information

With the accelerating progress of urbanization, the risk issues of city gas pipeline are increasing. It is very necessary to consider risk assessment of gas pipeline based on unascertained information because so much exists in the risk of gas pipeline.Firstly, it proposes a risk definition based on uncertain information and discusses risk measurement based on unascertainty. Risk is a set of possibilities that uncertain information may bring adverse results to a specific undertaker within a certain period of time and space in future. And five basic risk attributes are harmfulness, possibilities, dynamic, subjection and complementarity. The new measurement employ unascertained measure to express risk based on the formula of risk degree, which involves harmfulness, possibility and management capability.Secondly, risk assessment of gas pipeline based on unascertained information is discussed in detail. The index system of risk assessment of gas pipeline, with 36 bottom indexes and their grade standards, is given based on the proposed new formula. Then a new risk assessment model based on unascertained measure is introduced as well as its merits, especially two methods for calculating weight, including categorization weight based on information entropy and importance weight based on the Multi-agent Blind Number Model ( MABM ) .Thirdly, an example is introduced. Four distinguishing features are shown in the new model. First of all, uniform assessment standards of experts make the assenssment of different groups of experts comparable. Moreover, redundant information can't involve the synthesis of conclusions of risk because of the categorization weight and importance weights based on MABM are more simple and applied. Furthermore, more reasonable conclusions of risk can be obtained through recognition criterion of confidence level considering the orderliness of risk assessment space. At last, the radar chart can provide more information about risk.At last, conclusions and prospect are given to popularize the simpler and more reliable new assessment model and employ unascertained mathematics to deal with risk.