A comparative study is conducted to compare the theory and application effect of two accident causation models, the human factors analysis and classification system（HFACS） and the accident causation ＂2-4＂ model（2...A comparative study is conducted to compare the theory and application effect of two accident causation models, the human factors analysis and classification system（HFACS） and the accident causation ＂2-4＂ model（24 Model）, as well as to provide a reference for safety researchers and accident investigators to select an appropriate accident analysis method. The two models are compared in terms of their theoretical foundations, cause classifications, accident analysis processes, application ranges, and accident prevention strategies. A coal and gas outburst accident is then analyzed using both models, and the application results are compared. This study shows that both the 24 Model and HFACS have strong theoretical foundations, and they can each be applied in various domains. In addition, the cause classification in HFACS is more practical, and its accident analysis process is more convenient. On the other hand, the 24 Model includes external factors, which makes the cause analysis more systematic and comprehensive. Moreover, the 24 Model puts forward more corresponding measures to prevent accidents.展开更多
This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anat...This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element（FE） model and a multi-body system （MBS） model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.展开更多
Human factors are critical causes of modern aviation accidents. However, existing accident analysis methods encounter limitations in addressing aviation human factors, especially in complex accident scenarios. The exi...Human factors are critical causes of modern aviation accidents. However, existing accident analysis methods encounter limitations in addressing aviation human factors, especially in complex accident scenarios. The existing graphic approaches are effective for describing accident mechanisms within various categories of human factors, but cannot simultaneously describe inad- equate human-aircraft-environment interactions and organizational deficiencies effectively, and highly depend on analysts＇ skills and experiences. Moreover, the existing methods do not emphasize latent unsafe factors outside accidents. This paper focuses on the above three limitations and proposes an integrated graphi^taxonomic-associative approach. A new graphic model named accident tree （AceiTree）, with a two-mode structure and a reaction-based concept, is developed for accident modeling and safety defense identification. The AcciTree model is then integrated with the well-established human factors analysis and classification system （HFACS） to enhance both reliability of the graphic part and logicality of the taxonomic part for improving completeness of analysis. An associative hazard analysis technique is further put forward to extend analysis to fac- tors outside accidents, to form extended safety requirements for proactive accident prevention. Two crash examples, a research flight demonstrator by our team and an industrial unmanned aircraft, illustrate that the integrated approach is effective for identifying more unsafe factors and safety requirements.展开更多
In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. ...In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. By employing the complex network theory, especially its statistical indicators, the railway accident as well as its key causations can be analyzed from the overall perspective. As a case, the ＂7.23＂ China-Yongwen railway accident is illustrated based on this model. The results show that the inspection of signals and the checking of line conditions before trains run played an important role in this railway accident. In conclusion, the constructed model gives a theoretical clue for railway accident prediction and, hence, greatly reduces the occurrence of railway accidents.展开更多
The goal of this article is dual： first, introducing a new model of accident named STAMP （systems-theoretic accident modeling and processes）; then applying the model to an innovative process for the treatment of co...The goal of this article is dual： first, introducing a new model of accident named STAMP （systems-theoretic accident modeling and processes）; then applying the model to an innovative process for the treatment of contaminated substances and the re-use of treated substances. This article is a demonstration for a need of a new tool to take into account hazards and safety within socio-technical systems.展开更多
Assessment of harmful impacts and risks of air pollution in case of accidents as well as of long lasting exposition is an important challenge of chemical transport modeling. Sad confirmation of this statement unexpect...Assessment of harmful impacts and risks of air pollution in case of accidents as well as of long lasting exposition is an important challenge of chemical transport modeling. Sad confirmation of this statement unexpectedly has come from the nuclear power plant accident in Fukushima which occurred while this paper was finalized. Two strategies to comply with the task of impact and risk assessment in extended regions like Central Europe or the Balkans are described. The first one is characterized by application of a single model system to an extended domain. The other one is based on the combined application of several chemical transport models designed for the use in various sub-domains in the region under consideration. Advantages and disadvantages exist for both approaches. For instance, the single model strategy allows unified and harmonized assessment of risks in a larger region, whereas the combined model strategy may pro-vide faster and locally more specific response in emergency cases. The single model approach is treated exploiting applications of the EURAD model system. The combined model approach is a novel way of joint use of chemical transport model systems developed for the Balkans. The models are described and the accuracy of simulations carried out with them is briefly demonstrated by comparison of simulated and observed concentrations of air pollutants. Applications regarding the search of sources for high pollution events and the assessment of risks through known sources are exem-plarily discussed.展开更多
目的基于神经影像学特征及临床因素探究可独立行走的脑小血管病(cerebral small vessel disease,CSVD)患者跌倒风险的危险因素,建立预测模型并验证其效能。方法选择2021年9月—2024年9月就诊于河北医科大学第三医院可独立行走的CSVD患者...目的基于神经影像学特征及临床因素探究可独立行走的脑小血管病(cerebral small vessel disease,CSVD)患者跌倒风险的危险因素,建立预测模型并验证其效能。方法选择2021年9月—2024年9月就诊于河北医科大学第三医院可独立行走的CSVD患者315例,按6∶4比例分为建模人群(196例)和验证人群(119例)。采用起立-行走量表评估可独立行走的CSVD患者跌倒风险。在建模人群中行单因素及多因素分析可独立行走的CSVD患者跌倒风险的独立危险因素,构建跌倒风险预测模型并绘制诺莫图。分别在建模人群与验证人群中采用受试者工作特征(receiver operating characteristic,ROC)曲线下面积(area under the curve,AUC)、校准曲线评估模型的区分度、校准度。结果与无跌倒风险组患者相比,存在跌倒风险组患者的高龄、高血压病、骨折史、认知障碍、中重度白质高信号(white matter hyperintensity,WMH)、中重度EPVS、腔隙例数占比高,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,年龄(95%CI:1.356~3.256)、高血压病(95%CI:1.119~6.682)、认知障碍(95%CI:1.146~7.423)、中重度WMH(95%CI:1.487~8.363)、腔隙(95%CI:1.965~9.636)是可独立行走的CSVD患者跌倒风险的独立危险因素(P<0.05)。基于上述影响因素构建可独立行走的脑小血管病跌倒风险的诺莫图模型,建模人群和验证人群的ROC曲线下面积分别为0.855、0.921,模型区分度高,校准曲线显示该预测模型与实际观测结果有较好的一致性。结论高龄、高血压、中重度WMH、腔隙、认知障碍是可独立行走的CSVD患者跌倒风险的独立危险因素,依据本研究建立的临床预测模型可以较好的预测可独立行走的CSVD患者跌倒风险。展开更多
The wheel brake system safety is a complex problem which refers to its technical state, operating environment, human factors, etc., in aircraft landing taxiing process. Usually, professors consider system safety with ...The wheel brake system safety is a complex problem which refers to its technical state, operating environment, human factors, etc., in aircraft landing taxiing process. Usually, professors consider system safety with traditional probability techniques based on the linear chain of events. However, it could not comprehensively analyze system safety problems, especially in operating environment, interaction of subsystems, and human factors. Thus,we consider system safety as a control problem based on the system-theoretic accident model, the processes(STAMP) model and the system theoretic process analysis(STPA) technique to compensate the deficiency of traditional techniques. Meanwhile,system safety simulation is considered as system control simulation, and Monte Carlo methods are used which consider the range of uncertain parameters and operation deviation to quantitatively study system safety influence factors in control simulation. Firstly,we construct the STAMP model and STPA feedback control loop of the wheel brake system based on the system functional requirement. Then four unsafe control actions are identified, and causes of them are analyzed. Finally, we construct the Monte Carlo simulation model to analyze different scenarios under disturbance. The results provide a basis for choosing corresponding process model variables in constructing the context table and show that appropriate brake strategies could prevent hazards in aircraft landing taxiing.展开更多
To solve the problem of risk identification and quantitative assessment for human-computer interaction(HCI)in complex avionics systems,an HCI safety analysis framework based on system-theoretical process analysis(STPA...To solve the problem of risk identification and quantitative assessment for human-computer interaction(HCI)in complex avionics systems,an HCI safety analysis framework based on system-theoretical process analysis(STPA)and cognitive reliability and error analysis method(CREAM)is proposed.STPACREAM can identify unsafe control actions and find the causal path during the interaction of avionics systems and pilot with the help of formal verification tools automatically.The common performance conditions(CPC)of avionics systems in the aviation environment is established and a quantitative analysis of human failure is carried out.Taking the head-up display(HUD)system interaction process as an example,a case analysis is carried out,the layered safety control structure and formal model of the HUD interaction process are established.For the interactive behavior“Pilots approaching with HUD”,four unsafe control actions and35 causal scenarios are identified and the impact of common performance conditions at different levels on the pilot decision model are analyzed.The results show that HUD's HCI level gradually improves as the scores of CPC increase,and the quality of crew member cooperation and time sufficiency of the task is the key to its HCI.Through case analysis,it is shown that STPACREAM can quantitatively assess the hazards in HCI and identify the key factors that impact safety.展开更多
基金support from the State Key Program of the National Natural Science Foundation of China (No. 51534008)
文摘A comparative study is conducted to compare the theory and application effect of two accident causation models, the human factors analysis and classification system（HFACS） and the accident causation ＂2-4＂ model（24 Model）, as well as to provide a reference for safety researchers and accident investigators to select an appropriate accident analysis method. The two models are compared in terms of their theoretical foundations, cause classifications, accident analysis processes, application ranges, and accident prevention strategies. A coal and gas outburst accident is then analyzed using both models, and the application results are compared. This study shows that both the 24 Model and HFACS have strong theoretical foundations, and they can each be applied in various domains. In addition, the cause classification in HFACS is more practical, and its accident analysis process is more convenient. On the other hand, the 24 Model includes external factors, which makes the cause analysis more systematic and comprehensive. Moreover, the 24 Model puts forward more corresponding measures to prevent accidents.
基金National Natural Science Foundation of China(No. 10472031).
文摘This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element（FE） model and a multi-body system （MBS） model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.
基金co-supported by the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China (IRT0905)the Step Program of Beijing Key Laboratory (No. Z121104002812053)
文摘Human factors are critical causes of modern aviation accidents. However, existing accident analysis methods encounter limitations in addressing aviation human factors, especially in complex accident scenarios. The existing graphic approaches are effective for describing accident mechanisms within various categories of human factors, but cannot simultaneously describe inad- equate human-aircraft-environment interactions and organizational deficiencies effectively, and highly depend on analysts＇ skills and experiences. Moreover, the existing methods do not emphasize latent unsafe factors outside accidents. This paper focuses on the above three limitations and proposes an integrated graphi^taxonomic-associative approach. A new graphic model named accident tree （AceiTree）, with a two-mode structure and a reaction-based concept, is developed for accident modeling and safety defense identification. The AcciTree model is then integrated with the well-established human factors analysis and classification system （HFACS） to enhance both reliability of the graphic part and logicality of the taxonomic part for improving completeness of analysis. An associative hazard analysis technique is further put forward to extend analysis to fac- tors outside accidents, to form extended safety requirements for proactive accident prevention. Two crash examples, a research flight demonstrator by our team and an industrial unmanned aircraft, illustrate that the integrated approach is effective for identifying more unsafe factors and safety requirements.
基金Project supported by the National High Technology Research and Development Program of China (Grant No.2011AA110502)the National Natural Science Foundation of China (Grant No.71271022)the Research Foundation of State Key Laboratory of Rail Traffic Control and Safety,China (Grant No.RCS2012ZQ001)
文摘In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. By employing the complex network theory, especially its statistical indicators, the railway accident as well as its key causations can be analyzed from the overall perspective. As a case, the ＂7.23＂ China-Yongwen railway accident is illustrated based on this model. The results show that the inspection of signals and the checking of line conditions before trains run played an important role in this railway accident. In conclusion, the constructed model gives a theoretical clue for railway accident prediction and, hence, greatly reduces the occurrence of railway accidents.
文摘The goal of this article is dual： first, introducing a new model of accident named STAMP （systems-theoretic accident modeling and processes）; then applying the model to an innovative process for the treatment of contaminated substances and the re-use of treated substances. This article is a demonstration for a need of a new tool to take into account hazards and safety within socio-technical systems.
文摘Assessment of harmful impacts and risks of air pollution in case of accidents as well as of long lasting exposition is an important challenge of chemical transport modeling. Sad confirmation of this statement unexpectedly has come from the nuclear power plant accident in Fukushima which occurred while this paper was finalized. Two strategies to comply with the task of impact and risk assessment in extended regions like Central Europe or the Balkans are described. The first one is characterized by application of a single model system to an extended domain. The other one is based on the combined application of several chemical transport models designed for the use in various sub-domains in the region under consideration. Advantages and disadvantages exist for both approaches. For instance, the single model strategy allows unified and harmonized assessment of risks in a larger region, whereas the combined model strategy may pro-vide faster and locally more specific response in emergency cases. The single model approach is treated exploiting applications of the EURAD model system. The combined model approach is a novel way of joint use of chemical transport model systems developed for the Balkans. The models are described and the accuracy of simulations carried out with them is briefly demonstrated by comparison of simulated and observed concentrations of air pollutants. Applications regarding the search of sources for high pollution events and the assessment of risks through known sources are exem-plarily discussed.
文摘目的基于神经影像学特征及临床因素探究可独立行走的脑小血管病(cerebral small vessel disease,CSVD)患者跌倒风险的危险因素,建立预测模型并验证其效能。方法选择2021年9月—2024年9月就诊于河北医科大学第三医院可独立行走的CSVD患者315例,按6∶4比例分为建模人群(196例)和验证人群(119例)。采用起立-行走量表评估可独立行走的CSVD患者跌倒风险。在建模人群中行单因素及多因素分析可独立行走的CSVD患者跌倒风险的独立危险因素,构建跌倒风险预测模型并绘制诺莫图。分别在建模人群与验证人群中采用受试者工作特征(receiver operating characteristic,ROC)曲线下面积(area under the curve,AUC)、校准曲线评估模型的区分度、校准度。结果与无跌倒风险组患者相比,存在跌倒风险组患者的高龄、高血压病、骨折史、认知障碍、中重度白质高信号(white matter hyperintensity,WMH)、中重度EPVS、腔隙例数占比高,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,年龄(95%CI:1.356~3.256)、高血压病(95%CI:1.119~6.682)、认知障碍(95%CI:1.146~7.423)、中重度WMH(95%CI:1.487~8.363)、腔隙(95%CI:1.965~9.636)是可独立行走的CSVD患者跌倒风险的独立危险因素(P<0.05)。基于上述影响因素构建可独立行走的脑小血管病跌倒风险的诺莫图模型,建模人群和验证人群的ROC曲线下面积分别为0.855、0.921,模型区分度高,校准曲线显示该预测模型与实际观测结果有较好的一致性。结论高龄、高血压、中重度WMH、腔隙、认知障碍是可独立行走的CSVD患者跌倒风险的独立危险因素,依据本研究建立的临床预测模型可以较好的预测可独立行走的CSVD患者跌倒风险。
文摘The wheel brake system safety is a complex problem which refers to its technical state, operating environment, human factors, etc., in aircraft landing taxiing process. Usually, professors consider system safety with traditional probability techniques based on the linear chain of events. However, it could not comprehensively analyze system safety problems, especially in operating environment, interaction of subsystems, and human factors. Thus,we consider system safety as a control problem based on the system-theoretic accident model, the processes(STAMP) model and the system theoretic process analysis(STPA) technique to compensate the deficiency of traditional techniques. Meanwhile,system safety simulation is considered as system control simulation, and Monte Carlo methods are used which consider the range of uncertain parameters and operation deviation to quantitatively study system safety influence factors in control simulation. Firstly,we construct the STAMP model and STPA feedback control loop of the wheel brake system based on the system functional requirement. Then four unsafe control actions are identified, and causes of them are analyzed. Finally, we construct the Monte Carlo simulation model to analyze different scenarios under disturbance. The results provide a basis for choosing corresponding process model variables in constructing the context table and show that appropriate brake strategies could prevent hazards in aircraft landing taxiing.
基金supported by the National Key Research and Development Program of China(2021YFB1600601)the Joint Funds of the National Natural Science Foundation of China and the Civil Aviation Administration of China(U1933106)+2 种基金the Scientific Research Project of Tianjin Educational Committee(2019KJ134)the Natural Science Foundation of TianjinIntelligent Civil Aviation Program(21JCQNJ C00900)。
文摘To solve the problem of risk identification and quantitative assessment for human-computer interaction(HCI)in complex avionics systems,an HCI safety analysis framework based on system-theoretical process analysis(STPA)and cognitive reliability and error analysis method(CREAM)is proposed.STPACREAM can identify unsafe control actions and find the causal path during the interaction of avionics systems and pilot with the help of formal verification tools automatically.The common performance conditions(CPC)of avionics systems in the aviation environment is established and a quantitative analysis of human failure is carried out.Taking the head-up display(HUD)system interaction process as an example,a case analysis is carried out,the layered safety control structure and formal model of the HUD interaction process are established.For the interactive behavior“Pilots approaching with HUD”,four unsafe control actions and35 causal scenarios are identified and the impact of common performance conditions at different levels on the pilot decision model are analyzed.The results show that HUD's HCI level gradually improves as the scores of CPC increase,and the quality of crew member cooperation and time sufficiency of the task is the key to its HCI.Through case analysis,it is shown that STPACREAM can quantitatively assess the hazards in HCI and identify the key factors that impact safety.
