排序方式: 共有91条查询结果,搜索用时 36 毫秒
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李贵杰 《国防科技大学学报》2014,36(5)
摘要: 针对不确定性结构可靠性分析中的输入变量分布参数具有不确定性和输入变量为区间模型的混合不确定性结构展开研究。考虑可用信息最少的情况,将分布参数的不确定性描述为区间模型。通过等概率转换方法将随机变量与其分布参数进行分离,使问题转化为随机与区间变量混合的可靠性问题,建立了混合不确定性问题的可靠性分析模型。基于非概率可靠性理论,建立混合不确定结构分析模型的二级极限状态函数并结合Kriging代理模型建立了高效的求解方法。此外,将所建立的混合不确定模型应用于飞行器结构的不确定性分析中,验证所建模型的合理性和所提方法的高效性和准确性。 相似文献
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高脉冲重复频率雷达目标距离估计时面临距离模糊问题,因此必须采取一定方法解距离模糊。现有方法大都需要在每个驻留时间内至少两帧(包括两帧)检测到目标来实现目标距离估计,多假设方法虽然不要求在每个驻留时间内都需至少两帧检测到目标,但是当模糊区间发生变化时会出现目标距离估计错误。针对现有多假设方法的不足,提出改进的多假设方法,通过建立相关波门来判断目标所在的模糊区间是否改变并对目标状态作出修正,实现对模糊区间发生变化时目标距离的正确估计。仿真表明,方法可以不受模糊区间变化的影响,以较高精度实现目标距离估计。 相似文献
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The paper presents the possibilities of, and methods for, acquiring, analysing and processing optical signals in order to recognise, identify and counteract threats on the contemporary battleground. The main ways electronic warfare is waged in the optical band of the electromagnetic wave spectrum have been formulated, including the acquisition of optical emitter signatures, as well as ultraviolet (UV) and thermal (IR) signatures. The physical parameters and values describing the emission of laser radiation are discussed, including their importance in terms of creating optical signatures. Moreover, it has been shown that in the transformation of optical signals into signatures, only their spectral and temporal parameters can be applied. This was confirmed in experimental part of the paper, which includes our own measurements of spectral and temporal emission characteristics for three types of binocular laser rangefinders. It has been further shown that through simple registration and quick analysis involving comparison of emission time parameters in the case of UV signatures in “solar-blind” band, various events can be identified quickly and faultlessly. The same is true for IR signatures, where the amplitudes of the recorded signal for several wavelengths are compared. This was confirmed experimentally for UV signatures by registering and then analyzing signals from several events during military exercises at a training ground, namely Rocket Propelled Grenade (RPG) launches and explosions after hitting targets, trinitrotoluene (TNT) explosions, firing armour-piercing, fin-stabilised, discarding sabots (APFSDS) or high explosive (HE) projectiles. The final section describes a proposed model database of emitters, created as a result of analysing and transforming the recorded signals into optical signatures. 相似文献
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针对既有随机变量又有区间变量的模型预测结果与实验数据之间的一致性度量问题,对随机-区间混合不确定性模型确认指标进行研究。根据工程数学模型和实验过程中的不确定性来源,分析随机-区间混合不确定性模型确认的特点;运用概率方法和区间理论,提出新的随机-区间混合不确定性模型确认指标,讨论所提指标的性质,给出指标的计算方法和步骤。通过数字算例和工程算例,验证了所提指标的可行性和有效性。 相似文献
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风险偏好的区间值灰色模糊综合评判及其应用 总被引:1,自引:0,他引:1
由于被评判对象有时会带有某些不确定性以及信息量的多少及充分程度不同,使得这些对象在某些评判指标上属于某个评语的程度-隶属度及其对应的灰度不再是一个确定的数,常常是一个范围,针对此特点,尝试用区间值来表示灰度.引入一种反映风险偏好的风险指标,以此对评判结果灰度进行处理,定义了信息充分程度转化公式,利用其将评判结果转化为区间值集合,在此基础上建立了风险偏好的区间值灰色模糊综合评判的数学模型,并给出了它在方案优选中的应用.实例结果表明,这种方法是合理的、可行的、有效的. 相似文献
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