Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning

Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well‐established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents’ relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor‐based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates.     

事故致因理论述评

文章对各种事故致因理论形成的历史背景及研究视角进行了简要回顾,重点论述了海因里希事故因果边锁论、管理失误论、能量意外释放论、以人误为主因的事故模型、两类危险源理论、轨迹交叉论及Reason的复杂系统事故因果模型,并对他们的观点进行了评价,对其未来发展趋势进行了预测。     

Bivariate short distributions

The method of MML estimation for a univariate normal (Tiku 1967, 1973) is extended to a bivariate normal population. Thus, a theoretical foundation is given to the robust correlation coefficient proposed by Tiku and Balakrishnan (1986).     

Human and organizational factors in offshore safety

The role of human and organizational factors in predicting accidents and incidents has become of major interest to the UK offshore oil and gas industry. Some of these factors had been measured in an earlier study focusing on the role of risk perception in determining accident involvement. The current study sought to extend the methodology by focusing on perceptions of organizational factors that could have an impact on safety. A self-report questionnaire was developed and distributed to 11 installations operating on the UK Continental Shelf. A total of 722 were returned (33% response rate) from a representative sample of the offshore workforce on these installations. The study investigated the underlying structure and content of offshore employees' attitudes to safety, feelings of safety and satisfaction with safety measures. Correlations and step-wise regression analysis were used to test the relationships between measures. The results suggest that 'unsafe' behaviour is the 'best' predictor of accidents/near misses as measured by self-report data and that unsafe behaviour is, in turn, driven by perceptions of pressure for production.     

Conservatism of the Accident Sequence Evaluation Program HRA Procedure

This paper presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle for nuclear power plant operators. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. Comparison of the average of the ASEP HEP values with the fraction of the population actually failed and demonstrated that the ASEP HEP values are larger (conservative) by a statistically significant average factor of two. Partitioning of tasks into subgroups based on the ASEP HEP values and comparison of the subgroup average ASEP HEP values with observed subgroup failure rates showed little or no conservatism for small ASEP HEP values, but considerable conservatism for larger ASEP HEP values.     

Probabilistic Analysis of Dam Accidents Worldwide: Risk Assessment for Dams of Different Purposes in OECD and Non-OECD Countries with Focus on Time Trend Analysis

This study presents probabilistic analysis of dam accidents worldwide in the period 1911–2016. The accidents are classified by the dam purpose and by the country cluster, where they occurred, distinguishing between the countries of the Organization for Economic Cooperation and Development (OECD) and nonmember countries (non-OECD without China). A Bayesian hierarchical approach is used to model distributions of frequency and severity for accidents. This approach treats accident data as a multilevel system with subsets sharing specific characteristics. To model accident probabilities for a particular dam characteristic, this approach samples data from the entire data set, borrowing the strength across data set and enabling to model distributions even for subsets with scarce data. The modelled frequencies and severities are combined in frequency-consequence curves, showing that accidents for all dam purposes are more frequent in non-OECD (without China) and their maximum consequences are larger than in OECD countries. Multipurpose dams also have higher frequencies and maximum consequences than single-purpose dams. In addition, the developed methodology explicitly models time dependence to identify trends in accident frequencies over the analyzed period. Downward trends are found for almost all dam purposes confirming that technological development and implementation of safety measures are likely to have a positive impact on dam safety. The results of the analysis provide insights for dam risk management and decision-making processes by identifying key risk factors related to country groups and dam purposes as well as changes over time.     

清末上海城市交通事故与社会舆论——以《申报》相关报道为线索

城市新式交通工具的普及,在方便出行、延伸出行距离、扩大人们交往范围的同时,也带来了难以避免的交通事故。以人力车、马车为代表的非机动车辆作为城市主要交通工具的时期,由它们所引发的交通事故导致的对人身和财产的伤害,一时间为广大市民和社会舆论重视和关注,但舆论关注的重点、倾向以及两群体本身之间有明显的不同。     

The Risk of Photochemical Reactions

In January 1987, an incident occurred at a petrochemical complex in Salavat, Russia. The incident resulted in the poisioning of 17 people by the products of photochemical smog. This paper describes the incident and discusses the possibility of chemical reactions that pose toxic hazardous situations for chemical plant personnel. Pollutants present in the atmosphere as a result of continuous releases can result in the formation of toxic substances and the poisioning of people, even when permissible levels of concentrations are not exceeded for the initial pollutants. In addition, this paper addresses the need to consider the possibility of secondary chemical reactions in the environment while planning chemical plant activity.     

北魏末年灵胡太后述论

北魏末年的灵胡太后临朝称制，宣告终结“立子杀母”制，她依靠汉化的宗室贵族，平息羽林、虎贲之乱，实行新的选举方法，稳定了政局，但她后期私欲极度膨胀，信任佞臣，甚至杀害自己的儿子孝明帝，引发了北魏末年政治的一大变局，即尔朱荣占领洛阳和“河阴之变”。     

机动车单车事故情形下的保险金给付责任——驾驶员被自己所停车辆溜压致死之情形

机动车单车事故乃指无加害人存在之机动车事故.在我国,由于机动车对人赔偿保险均采用责任保险方式,保险人给付保险金的前提乃被保险人承担损害赔偿责任,因此单车事故受害人无法得到保险保障.驾驶员被自己所停车辆溜压致死的为典型的单车事故,虽然受害人属于条款所约定的"第三者",但判断保险人是否承担责任时必须明确相关保险条款的制定目的及其相互间的内在逻辑关系,不能忽视任何一款规定之应有法律规范作用,在立法论的制度设计上需给予单车事故受害人应有的保护.