为了提高某型飞机起落架故障诊断率,分别采用故障树分析法(Fault Tree Analysis,FTA)和FTA与RBF神经网络(Radial Basis Function,RBF)的方法对起落架常见故障进行诊断。首先根据起落架工作原理图,采用FTA方法建立故障树及故障结构函数,...为了提高某型飞机起落架故障诊断率,分别采用故障树分析法(Fault Tree Analysis,FTA)和FTA与RBF神经网络(Radial Basis Function,RBF)的方法对起落架常见故障进行诊断。首先根据起落架工作原理图,采用FTA方法建立故障树及故障结构函数,得到所有的最小割集,计算故障失效概率;然后按照最小割集重要度,筛选出RBF神经网络训练样本的变量数目;最后再结合国内某维修单位的故障统计数据,运用RBF神经网络建立了故障诊断模型,并对模型进行了训练和测试。结果表明,FTA定量计算得到的故障失效概率为71.60%,FTA+RBF结合方法的故障诊断平均预测误差为1.0%。展开更多
Lifelines, such as pipeline, transportation, communication, electric transmission and medical rescue systems, are complicated networks that always distribute spatially over large geological and geographic units. The q...Lifelines, such as pipeline, transportation, communication, electric transmission and medical rescue systems, are complicated networks that always distribute spatially over large geological and geographic units. The quantification of their reliability under an earthquake occurrence should be highly regarded, because the performance of these systems during a destructive earthquake is vital in order to estimate direct and indirect economic losses from lifeline failures, and is also related to laying out a rescue plan. The research in this paper aims to develop a new earthquake reliability calculation methodology for lifeline systems. The methodology of the network reliability for lifeline systems is based on fault tree analysis (FTA) and geological information system (GIS). The interactions existing in a lifeline system are considered herein. The lifeline systems are idealized as equivalent networks, consisting of nodes and links, and are described by network analysis in GIS. Firstly, the node is divided into two types: simple node and complicated node, where the reliability of the complicated node is calculated by FTA and interaction is regarded as one factor to affect performance of the nodes. The reliability of simple node and link is evaluated by code. Then, the reliability of the entire network is assessed based on GIS and FTA. Lastly, an illustration is given to show the methodology.展开更多
为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)...为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。展开更多
针对某型飞机冷气系统常见的渗漏故障,结合其结构原理图,首先运用FTA(Fault Tree Analysis)方法,分析得到了该型飞机冷气系统渗漏的所有故障模式及最小割集,建立了故障树的结构函数。再根据故障模式的主要类别,筛选、整理出BP(Back Prop...针对某型飞机冷气系统常见的渗漏故障,结合其结构原理图,首先运用FTA(Fault Tree Analysis)方法,分析得到了该型飞机冷气系统渗漏的所有故障模式及最小割集,建立了故障树的结构函数。再根据故障模式的主要类别,筛选、整理出BP(Back Propagation)神经网络的训练样本,运用BP神经网络的方法建立了该型飞机冷气系统渗漏故障诊断模型,并对模型进行了验证。采用“FTA+BP神经网络”相结合的故障诊断方法,克服了FTA与BP神经网络方法单独诊断时的固有缺陷,提高了故障诊断的准确性和高效性,探索了新的故障诊断方法。展开更多
The purpose of this study is to explore the impact of regional network(regional economies integration)dynamics(integration of free trade agreements[FTAs]/regional trade agreements[RTAs]in Asia-Pacific economies)on Tai...The purpose of this study is to explore the impact of regional network(regional economies integration)dynamics(integration of free trade agreements[FTAs]/regional trade agreements[RTAs]in Asia-Pacific economies)on Taiwan’s trade(export)and outward foreign direct investment(OFDI)flows.This study uses two models to estimate export and FDI respectively to investigate the impact of regional network dynamics on individuals,and the impact of trade effects on FDI.Research period is 2001-2016.Estimated findings indicate that Taiwan’s exports are highly dependent on major Asian countries,and the GDP growth of major trading countries has no significant effect on Taiwan’s exports,but the GDP growth of major Asian countries has positive and significant effects on Taiwan’s FDIs.Exports have no significant effects mostly on FDI,which implies that Taiwan’s main OFDIs have no significant correlation with export orientation.In terms of regional network integration,the impact of the initial regional network integration(ASEAN plus three countries)has no significant effects mostly on the export flows of Taiwan’s trading countries,but has relatively significant effects on the FDI flows of Taiwan’s FDI countries;the impact of the relatively mature regional network integration(ASEAN plus six countries)has negative effects on the export and FDI flows of Taiwan’s major trading and FDI countries,especially Association of Southeast Asian Nations(ASEAN)and Japan.The impact of the bilateral economic agreement(Economic Cooperation Framework Agreement[ECFA])has positive and significant effects on the export flows of Taiwan’s major trading countries,especially in Asian countries;while for FDI countries has only a positive and significant effect on China,but has a negative and significant effect on ASEAN.According to the analysis results,regional network integration appears to have significant negative effects on Taiwan’s major trading and FDI partners.展开更多
文摘为了提高某型飞机起落架故障诊断率,分别采用故障树分析法(Fault Tree Analysis,FTA)和FTA与RBF神经网络(Radial Basis Function,RBF)的方法对起落架常见故障进行诊断。首先根据起落架工作原理图,采用FTA方法建立故障树及故障结构函数,得到所有的最小割集,计算故障失效概率;然后按照最小割集重要度,筛选出RBF神经网络训练样本的变量数目;最后再结合国内某维修单位的故障统计数据,运用RBF神经网络建立了故障诊断模型,并对模型进行了训练和测试。结果表明,FTA定量计算得到的故障失效概率为71.60%,FTA+RBF结合方法的故障诊断平均预测误差为1.0%。
基金Sponsored by the Natural Science Foundation of China (Grant No.50278028) the Scientific Research Foundation of Harbin Institute of Technology(Grant No.HIT200079).
文摘Lifelines, such as pipeline, transportation, communication, electric transmission and medical rescue systems, are complicated networks that always distribute spatially over large geological and geographic units. The quantification of their reliability under an earthquake occurrence should be highly regarded, because the performance of these systems during a destructive earthquake is vital in order to estimate direct and indirect economic losses from lifeline failures, and is also related to laying out a rescue plan. The research in this paper aims to develop a new earthquake reliability calculation methodology for lifeline systems. The methodology of the network reliability for lifeline systems is based on fault tree analysis (FTA) and geological information system (GIS). The interactions existing in a lifeline system are considered herein. The lifeline systems are idealized as equivalent networks, consisting of nodes and links, and are described by network analysis in GIS. Firstly, the node is divided into two types: simple node and complicated node, where the reliability of the complicated node is calculated by FTA and interaction is regarded as one factor to affect performance of the nodes. The reliability of simple node and link is evaluated by code. Then, the reliability of the entire network is assessed based on GIS and FTA. Lastly, an illustration is given to show the methodology.
文摘为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。
文摘针对某型飞机冷气系统常见的渗漏故障,结合其结构原理图,首先运用FTA(Fault Tree Analysis)方法,分析得到了该型飞机冷气系统渗漏的所有故障模式及最小割集,建立了故障树的结构函数。再根据故障模式的主要类别,筛选、整理出BP(Back Propagation)神经网络的训练样本,运用BP神经网络的方法建立了该型飞机冷气系统渗漏故障诊断模型,并对模型进行了验证。采用“FTA+BP神经网络”相结合的故障诊断方法,克服了FTA与BP神经网络方法单独诊断时的固有缺陷,提高了故障诊断的准确性和高效性,探索了新的故障诊断方法。
文摘The purpose of this study is to explore the impact of regional network(regional economies integration)dynamics(integration of free trade agreements[FTAs]/regional trade agreements[RTAs]in Asia-Pacific economies)on Taiwan’s trade(export)and outward foreign direct investment(OFDI)flows.This study uses two models to estimate export and FDI respectively to investigate the impact of regional network dynamics on individuals,and the impact of trade effects on FDI.Research period is 2001-2016.Estimated findings indicate that Taiwan’s exports are highly dependent on major Asian countries,and the GDP growth of major trading countries has no significant effect on Taiwan’s exports,but the GDP growth of major Asian countries has positive and significant effects on Taiwan’s FDIs.Exports have no significant effects mostly on FDI,which implies that Taiwan’s main OFDIs have no significant correlation with export orientation.In terms of regional network integration,the impact of the initial regional network integration(ASEAN plus three countries)has no significant effects mostly on the export flows of Taiwan’s trading countries,but has relatively significant effects on the FDI flows of Taiwan’s FDI countries;the impact of the relatively mature regional network integration(ASEAN plus six countries)has negative effects on the export and FDI flows of Taiwan’s major trading and FDI countries,especially Association of Southeast Asian Nations(ASEAN)and Japan.The impact of the bilateral economic agreement(Economic Cooperation Framework Agreement[ECFA])has positive and significant effects on the export flows of Taiwan’s major trading countries,especially in Asian countries;while for FDI countries has only a positive and significant effect on China,but has a negative and significant effect on ASEAN.According to the analysis results,regional network integration appears to have significant negative effects on Taiwan’s major trading and FDI partners.
