Target tracking using non-threshold raw data with low signal-to-noise ratio is a very difficult task, and the model uncertainty introduced by target's maneuver makes it even more challenging. In this work, a multi...Target tracking using non-threshold raw data with low signal-to-noise ratio is a very difficult task, and the model uncertainty introduced by target's maneuver makes it even more challenging. In this work, a multiple-model based method was proposed to tackle such issues. The method was developed in the framework of Bernoulli filter by integrating the model probability parameter and implemented via sequential Monte Carlo(particle) technique. Target detection was accomplished through the estimation of target's existence probability, and the estimate of target state was obtained by combining the outputs of modeldependent filtering. The simulation results show that the proposed method performs better than the TBD method implemented by the conventional multiple-model particle filter.展开更多
研究质谱的离子传输气体动力学特征对理解和提升质谱仪器灵敏度具有重要意义。基于纳维-斯托克斯(NavierStokes)方程和直接蒙特卡洛(Direct Simulation Monte Carlo)方法联用,可以计算获得气体从大气压连续流到真空稀薄流的流场特征,进...研究质谱的离子传输气体动力学特征对理解和提升质谱仪器灵敏度具有重要意义。基于纳维-斯托克斯(NavierStokes)方程和直接蒙特卡洛(Direct Simulation Monte Carlo)方法联用,可以计算获得气体从大气压连续流到真空稀薄流的流场特征,进一步与电场仿真耦合,可以获得离子的传输与空间分布信息,评价离子光学器件性能。工作基于光电离质谱,构建了毛细管进样、光电离源和取样锥的组合结构模型,建立了离子传输跨流态多物理场仿真方法,得到了两种结构光电离源电极对离子传输效率的影响,并利用自制光电离飞行时间质谱装置验证了仿真方法的可靠性。工作为复杂流场和电场环境下质谱光电离源及离子传输装置设计提供了理论指导依据。展开更多
现有的基于失效物理(physics of failure,PoF)模型的可靠性预计只能计算电子产品在寿命周期内经历单一典型任务剖面的失效时间。本文提出了一种基于失效物理模型,并利用蒙特卡罗仿真定量分析电子产品在寿命周期内实际经历多任务剖面的...现有的基于失效物理(physics of failure,PoF)模型的可靠性预计只能计算电子产品在寿命周期内经历单一典型任务剖面的失效时间。本文提出了一种基于失效物理模型,并利用蒙特卡罗仿真定量分析电子产品在寿命周期内实际经历多任务剖面的可靠性水平的新方法。将该方法应用于某机载电子设备的平均失效前时间(mean time to failure,MTTF)的计算,建立失效率和可靠度的时间函数,与目前国内工程实践中常用的失效率经验模型法以及设备可靠性强化试验的结果进行了对比分析。结果表明,该方法不仅可以计算可靠性参数,而且通过分析与计算过程可发现设计薄弱环节与可靠性参数的定量关系,有效指导设计改进。展开更多
基金Projects(61002022,61471370)supported by the National Natural Science Foundation of China
文摘Target tracking using non-threshold raw data with low signal-to-noise ratio is a very difficult task, and the model uncertainty introduced by target's maneuver makes it even more challenging. In this work, a multiple-model based method was proposed to tackle such issues. The method was developed in the framework of Bernoulli filter by integrating the model probability parameter and implemented via sequential Monte Carlo(particle) technique. Target detection was accomplished through the estimation of target's existence probability, and the estimate of target state was obtained by combining the outputs of modeldependent filtering. The simulation results show that the proposed method performs better than the TBD method implemented by the conventional multiple-model particle filter.
文摘研究质谱的离子传输气体动力学特征对理解和提升质谱仪器灵敏度具有重要意义。基于纳维-斯托克斯(NavierStokes)方程和直接蒙特卡洛(Direct Simulation Monte Carlo)方法联用,可以计算获得气体从大气压连续流到真空稀薄流的流场特征,进一步与电场仿真耦合,可以获得离子的传输与空间分布信息,评价离子光学器件性能。工作基于光电离质谱,构建了毛细管进样、光电离源和取样锥的组合结构模型,建立了离子传输跨流态多物理场仿真方法,得到了两种结构光电离源电极对离子传输效率的影响,并利用自制光电离飞行时间质谱装置验证了仿真方法的可靠性。工作为复杂流场和电场环境下质谱光电离源及离子传输装置设计提供了理论指导依据。
文摘现有的基于失效物理(physics of failure,PoF)模型的可靠性预计只能计算电子产品在寿命周期内经历单一典型任务剖面的失效时间。本文提出了一种基于失效物理模型,并利用蒙特卡罗仿真定量分析电子产品在寿命周期内实际经历多任务剖面的可靠性水平的新方法。将该方法应用于某机载电子设备的平均失效前时间(mean time to failure,MTTF)的计算,建立失效率和可靠度的时间函数,与目前国内工程实践中常用的失效率经验模型法以及设备可靠性强化试验的结果进行了对比分析。结果表明,该方法不仅可以计算可靠性参数,而且通过分析与计算过程可发现设计薄弱环节与可靠性参数的定量关系,有效指导设计改进。
