基于案例知识的系统安全风险模型

Case Knowledge-based System Safety Risk Model

对基于案例知识的系统安全风险模型进行了研究。首先,建立了系统安全事件案例知识表达模型。其次,研究了系统知识表达的不确定性问题,以及安全风险决策者的决策类型对度量不确定性的需求;基于现有安全风险模型对不确定性度量能力的欠缺,提出了基于案例知识的系统安全风险概念模型,用损失可能性、损失程度和损失的不确定性来表征系统安全风险。在此基础上,研究了该安全风险模型的建模方法,并举例证明了该模型的有效性。最后,对机长飞行安全风险进行了研究,选取机长年龄、累计飞行小时以及近90天飞行小时3个指标作为风险因子,应用本文所建基于案例知识的系统安全风险模型,评估了机长飞行安全风险,评估结果合理,可为民航放飞决策提供参考。

This article is a study about a knowledge-based complex system safety risk model. First,a know-ledge representation model of complex system safety occurrence cases is presented. Second,the uncertainty of knowledge representation as well as the requirement for uncertainty quantifications by the safety risk decision-maker is discussed. Thus,a knowledge-based system safety risk model is presented,where risk is a function of loss probability,loss degree,and loss uncertainty. Then,the modeling method of the proposed model is given,and an instance to demonstrate its application is provided. Finally,the model is used in the safety risk assessment of a civil aircraft flight operation. The attributes of pilot age,total pilot flight hours,and pilot flight hours in the past 90 days are selected as risk factors to assess the flight safety risk of the pilot. The assessment result demonstrates the validity of the proposed model.