Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking J...Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking Jinji（Tianjin--Jixian） Highway of Tianjin as an example, the errors of system simulation are tested, and the system dynamics model built is verified to be quite stable, which has a high performance. Through the comparison of simulation results with and without Jinji Highway, the paper simulates and predicts the socio-economie benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio-economic benefit of highway project is realized and will provide the theory instructions for similar projects in the future.展开更多
为了根据空中飞行弹箭的一段实测弹道参数,准确预报弹道落点,并实施弹道修正,实现对目标的精确打击,在阐述弹道修正弹飞行原理的基础上,建立了扩展卡尔曼气动参数辨识弹道模型。该模型可对一段实测弹道参数进行弹道滤波,辨识出空中飞行...为了根据空中飞行弹箭的一段实测弹道参数,准确预报弹道落点,并实施弹道修正,实现对目标的精确打击,在阐述弹道修正弹飞行原理的基础上,建立了扩展卡尔曼气动参数辨识弹道模型。该模型可对一段实测弹道参数进行弹道滤波,辨识出空中飞行弹丸的实际阻力和升力符合系数,并能较准确预报其后续飞行弹道。数值计算结果表明,经扩展卡尔曼弹道滤波后,能有效剔除测量弹道参数的噪声,且坐标滤波方差、阻力和升力符合系数迅速收敛；预报弹道落点的精度与飞行弹道参数的测量时间和采样时间间隔有关,考虑到实时弹道预报方法的预报弹道落点精度和解算时间等,飞行弹道参数测量时间宜取6~8 s,采样时间间隔宜在60~120 ms 范围内选取,为弹箭实现弹道修正提供了参考。展开更多
基金Technology Plan Projects of Tianjin Planning Bureau(No.2010H3-0011)
文摘Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking Jinji（Tianjin--Jixian） Highway of Tianjin as an example, the errors of system simulation are tested, and the system dynamics model built is verified to be quite stable, which has a high performance. Through the comparison of simulation results with and without Jinji Highway, the paper simulates and predicts the socio-economie benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio-economic benefit of highway project is realized and will provide the theory instructions for similar projects in the future.
文摘为了根据空中飞行弹箭的一段实测弹道参数,准确预报弹道落点,并实施弹道修正,实现对目标的精确打击,在阐述弹道修正弹飞行原理的基础上,建立了扩展卡尔曼气动参数辨识弹道模型。该模型可对一段实测弹道参数进行弹道滤波,辨识出空中飞行弹丸的实际阻力和升力符合系数,并能较准确预报其后续飞行弹道。数值计算结果表明,经扩展卡尔曼弹道滤波后,能有效剔除测量弹道参数的噪声,且坐标滤波方差、阻力和升力符合系数迅速收敛；预报弹道落点的精度与飞行弹道参数的测量时间和采样时间间隔有关,考虑到实时弹道预报方法的预报弹道落点精度和解算时间等,飞行弹道参数测量时间宜取6~8 s,采样时间间隔宜在60~120 ms 范围内选取,为弹箭实现弹道修正提供了参考。
