排序方式: 共有77条查询结果,搜索用时 31 毫秒
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针对指数寿命产品的定时、定数截尾试验方案,推广了Mazzuchi-Soyer模型的应用范围。首先引入模型假设,以狄氏分布作为先验分布,综合利用产品研制的历史信息和专家信息,结合产品研制各阶段试验数据,给出了各阶段可靠性的联合后验分布。然后利用Gibbs抽样算法解决后验推断计算问题,得到各阶段产品可靠性的Bayes点估计和区间估计。最后给出产品可靠性增长分析实例,表明了模型的优越性。 相似文献
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准确估计初始误差和制导工具误差是机动发射飞行器精度鉴定必须解决的重要问题之一,提出了一种基于非线性模型的误差估计新方法。给出了平台初始失准角向定向误差的转换方法,采用不动点迭代法实现真实视加速度的精确计算,将真实发射系的轨道参数表示为初始误差和工具误差的非线性函数,结合外测数据建立了同时估计初始误差、工具误差、外测系统误差、遥外测时间零点偏差的非线性模型,避免了初始误差的线性化近似。给出了Bayes极大后验估计方法,利用非线性模型和先验信息获得误差的最优估计,证明了估计方法的收敛性。仿真结果表明,所提方法提高了初始误差和工具误差的估计精度,并实现了测量数据的自校准。 相似文献
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无线通信网是消防部队在执行灭火抢险救援任务时,确保完成信息传达、灭火抢险救援指挥、协同作战等任务的关键。为了更好的开发集群通信的功能,介绍了集群通信的概念、组网方式,并探讨了通信区域扩展的方法。 相似文献
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This paper presents a branch and bound algorithm for computing optimal replacement policies in a discrete‐time, infinite‐horizon, dynamic programming model of a binary coherent system with n statistically independent components, and then specializes the algorithm to consecutive k‐out‐of‐n systems. The objective is to minimize the long‐run expected average undiscounted cost per period. (Costs arise when the system fails and when failed components are replaced.) An earlier paper established the optimality of following a critical component policy (CCP), i.e., a policy specified by a critical component set and the rule: Replace a component if and only if it is failed and in the critical component set. Computing an optimal CCP is a optimization problem with n binary variables and a nonlinear objective function. Our branch and bound algorithm for solving this problem has memory storage requirement O(n) for consecutive k‐out‐of‐n systems. Extensive computational experiments on such systems involving over 350,000 test problems with n ranging from 10 to 150 find this algorithm to be effective when n ≤ 40 or k is near n. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 288–302, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10017 相似文献
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舰载武器发射或舰载武器惯导系统对准需要舰载惯导系统MINS的信息辅助,不同的安装位置使得它们之间存在较大的杆臂效应,在对杆臂效应补偿中需要三维杆臂尺寸参数,由于加工误差、安装误差及船体变形,使武器战位的实际杆臂参数偏离图纸计算值.通常舰载惯导舱室与甲板武器战位之间不能通视直接测量难度大.为提高杆臂效应补偿精度,提出了基于舰载惯导MINS及差分GPS辅助的测量方案.通过速度信息观测采用马尔科夫递推滤波器估计杆臂参数,仿真结果表明通过10min的测量可达到0.1m估计精度量级. 相似文献
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射频模块存在相位特性的非线性效应,群延迟随频率的变化不再是一个常数,并可能造成输出射频信号的波形失真,而影响精密射频信号源的输出精度。基于递归最小二乘算法的自适应滤波器,提出了消除其非线性效应的新方法。并以GPS模拟源为例,利用其自校模块,采用软件无线电和数字信号处理技术,精确估计出射频模块的模型参数。将基带合成信号通过一个数字逆滤波器,以消除相位的非线性和群延迟随频率的变化。利用自编的仿真程序包,在Matlab中进行了相应的模拟计算。仿真结果表明,该方法可有效地消除相位非线性效应对射频信号的影响,输出信号的波形失真在理论上可控制在0.01%以内。 相似文献
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A naval task group (TG) is a collection of naval combatants and auxiliaries that are grouped together for the accomplishment of one or more missions. Ships forming a TG are located in predefined sectors. We define determination of ship sector locations to provide a robust air defense formation as the sector allocation problem (SAP). A robust formation is one that is very effective against a variety of attack scenarios but not necessarily the most effective against any scenario. We propose a 0‐1 integer linear programming formulation for SAP. The model takes the size and the direction of threat into account as well as the defensive weapons of the naval TG. We develop tight lower and upper bounds by incorporating some valid inequalities and use a branch and bound algorithm to exactly solve SAP. We report computational results that demonstrate the effectiveness of the proposed solution approach. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
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为了求解磁性目标跟踪问题的后验克拉美罗下限(PCRB),提出了PCRB-GMSPPF算法。该算法利用高斯混合采样粒子滤波算法对目标状态的真实后验概率密度分布进行抽样,再通过蒙特卡洛积分法迭代求解每个观测时刻的Fisher信息矩阵,进而得出目标状态估计的PCRB;克服了基于PF算法求解PCRB过程中由于粒子退化和贫化问题造成不能从后验概率分布中正确抽样的缺点;在建立磁性目标跟踪的状态模型和观测模型的基础上进行仿真分析,将求解出的PCRB与采用GMSPPF及PF算法进行跟踪的均方根误差做对比,验证所提的PCRB-GMSPPF算法的有效性,结果表明:针对磁性目标跟踪问题,PCRB-GMSPPF算法较PCRB-PF算法具有更好的准确性,并可用于一般的非线性模型跟踪误差下限分析。 相似文献