降雨时空分布的随机性,下垫面的复杂性,以及管网在设计、施工、使用过程中的不确定性,导致排水管网水力模型参数取值存在着不确定性.为了评估参数不确定性对节点和管道功能状态评价的影响,建立了考虑降雨输入、产流、汇流、管网水动力...降雨时空分布的随机性,下垫面的复杂性,以及管网在设计、施工、使用过程中的不确定性,导致排水管网水力模型参数取值存在着不确定性.为了评估参数不确定性对节点和管道功能状态评价的影响,建立了考虑降雨输入、产流、汇流、管网水动力计算各过程不确定性参数的分析模型.根据建模流程的参数要求和文献结论,选择了暴雨洪水管理模型(storm water management model,SWMM)建模过程中的14个参数作为不确定性参数;基于模型参数的增量对计算结果的影响分析,进行了参数灵敏度排序,选取了5个主要参数进行不确定性分析;基于SWMM求解器,采用Monte Carlo随机模拟方法计算了节点、管道的失效概率和相应的溢流时间、体积、充满度模拟均值、变异系数;通过对比参数取中值的确定性工况计算出的节点、管道的相应结果,分析了不确性与确定性分析结果的差异性.算例分析结果表明:在降雨输入和模型计算过程中均存在影响较大的不确定性参数,有必要考虑模型计算全过程参数的不确定性;相对于确定性工况,不确定性分析模型对高风险概率的节点和管道具有较好的识别效果;不确定性分析识别出的不可靠节点的溢流时间、体积模拟值相对确定性工况全网平均值的变化率分别达到了29.13%、10.41%,各管道充满度的变化率最高可达22.31%.展开更多
The high level of safety demand of civil aviation requests local area augmentation system （LAAS） extremely high navigation integrity performance. A new LAAS pseudo-range error overbound method is proposed in this pa...The high level of safety demand of civil aviation requests local area augmentation system （LAAS） extremely high navigation integrity performance. A new LAAS pseudo-range error overbound method is proposed in this paper to improve the integrity of LAAS. Firstly, a more practical pseudo-range error distribution model is established. Then, by calculating the relationship between the statistical uncertainty of the model parameter and the integrity risk, a new method is proposed to calculate the pseudo-range error over-bound model. This method can effectively reduce the inflation factor and the resulting conservativeness of the over-bound model. Comparative experiments show that the method proposed in this paper performs better and satisfies the requirements of real applications.展开更多
文摘降雨时空分布的随机性,下垫面的复杂性,以及管网在设计、施工、使用过程中的不确定性,导致排水管网水力模型参数取值存在着不确定性.为了评估参数不确定性对节点和管道功能状态评价的影响,建立了考虑降雨输入、产流、汇流、管网水动力计算各过程不确定性参数的分析模型.根据建模流程的参数要求和文献结论,选择了暴雨洪水管理模型(storm water management model,SWMM)建模过程中的14个参数作为不确定性参数;基于模型参数的增量对计算结果的影响分析,进行了参数灵敏度排序,选取了5个主要参数进行不确定性分析;基于SWMM求解器,采用Monte Carlo随机模拟方法计算了节点、管道的失效概率和相应的溢流时间、体积、充满度模拟均值、变异系数;通过对比参数取中值的确定性工况计算出的节点、管道的相应结果,分析了不确性与确定性分析结果的差异性.算例分析结果表明:在降雨输入和模型计算过程中均存在影响较大的不确定性参数,有必要考虑模型计算全过程参数的不确定性;相对于确定性工况,不确定性分析模型对高风险概率的节点和管道具有较好的识别效果;不确定性分析识别出的不可靠节点的溢流时间、体积模拟值相对确定性工况全网平均值的变化率分别达到了29.13%、10.41%,各管道充满度的变化率最高可达22.31%.
基金the National Natural Science Foundation of China(61179054)the National Basic Research Program of China(2011CB707004)the National Key Technology R&D Program(2011BAH24B02)
文摘The high level of safety demand of civil aviation requests local area augmentation system （LAAS） extremely high navigation integrity performance. A new LAAS pseudo-range error overbound method is proposed in this paper to improve the integrity of LAAS. Firstly, a more practical pseudo-range error distribution model is established. Then, by calculating the relationship between the statistical uncertainty of the model parameter and the integrity risk, a new method is proposed to calculate the pseudo-range error over-bound model. This method can effectively reduce the inflation factor and the resulting conservativeness of the over-bound model. Comparative experiments show that the method proposed in this paper performs better and satisfies the requirements of real applications.
