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排序方式: 共有508条查询结果,搜索用时 31 毫秒
451.
竞争失效场合加速试验技术是加速试验由简单结构产品向复杂结构产品推广应用的基础,而如何设计试验方案使统计结果最准确、代价最小,是其中的主要研究内容之一.针对传统解析优化方法推导过程比较复杂的问题,提出了一种基于Monte Carlo仿真的竞争失效场合加速试验优化设计方法.在备选方案较多的情况下,通过引入曲面拟合进行间接优... 相似文献
452.
We consider a discrete‐time groundwater model in which the cost of pumping takes a slightly different form to that which has been traditional in the research literature to date. This enables us to prove that (a) the optimal pumping quantity is nondecreasing in the ground water stock, (b) the stock level remaining after each period's pumping is also nondecreasing in the groundwater stock, (c) the optimal decision is determined by maximizing a concave function, and finally (d) the optimal pumping quantity is nonincreasing in the number of periods to go. We show that (a)–(c), while intuitive, do not hold under traditional modeling assumptions. We also explain the connections between our results and similar ones for some classic problems of operations research. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 00: 000–000, 2011 相似文献
453.
A Markov chain approach to detecting a threat in a given surveillance zone by a network of steerable sensors is presented. The network has a finite number of predetermined states, and transition from one state to another follows a Markov chain. Under the assumption that the threat avoids detection, two game theoretic problems for finding an optimal Markov chain (two surveillance strategies) are formulated: the first maximizes the probability of threat detection for two consecutive detection periods, whereas the second minimizes the average time of detection for the worst‐case threat's trajectory. Both problems are reduced to linear programming, and special techniques are suggested to solve them. For a dynamic environment with moving noise sources, the optimal Markov chain changes at each detection period, and the rate of convergence of the Markov chain to its stationary distribution is analyzed. Both surveillance strategies are tested in numerical experiments and compared one with another. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
454.
基于提升结构的因果化实现及优化在将两带滤波器组转化为单进单出系统时子带系数的叠混模式,提出了一种改进的低内存需求的离散小波变换(Enhanced Low-memory Discrete Wavelet Transform,ELDWT)实现方法.相对于DWT的常规全局实现法,基于ELDWT实现的正、逆离散小波变换均具有与... 相似文献
455.
针对系统误差变化规律未知时的传感器探测系统偏差估计问题,提出了一种改进的基于Mean-Shift(均值偏移)的传感器动态偏差估计算法.该算法利用Mean-Shift方法对不同样本点对估计结果贡献不同的特点,根据样本点偏离均值的偏移量以及偏移时间构建权系数.仿真结果表明,该方法在系统误差变化规律未知的情况下,可有效估计多... 相似文献
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惯性传感技术发展与展望 总被引:5,自引:1,他引:4
利用GPS辅助INS的系统已在各种应用领域崭露头角,这些新的应用领域将驱动市场对极低成本惯性传感器的大量需求。在回顾惯性传感技术的发展历程、研究热点、应用领域的基础上,讨论和展望了光纤陀螺仪、微机械陀螺仪和加速度计,以及微型光学传感器技术近期和远期的发展趋势。 相似文献
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Reliability Economics is a field that can be defined as the collection of all problems in which there is tension between the performance of systems of interest and their cost. Given such a problem, the aim is to resolve the tension through an optimization process that identifies the system which maximizes some appropriate criterion function (e.g. expected lifetime per unit cost). In this paper, we focus on coherent systems of n independent and identically distributed (iid) components and mixtures thereof, and characterize both a system's performance and cost as functions of the system's signature vector (Samaniego, IEEE Trans Reliabil (1985) 69–72). For a given family of criterion functions, a variety of optimality results are obtained for systems of arbitrary order n. Approximations are developed and justified when the underlying component distribution is unknown. Assuming the availability of an auxiliary sample of N component failure times, the asymptotic theory of L‐estimators is adapted for the purpose of establishing the consistency and asymptotic normality of the proposed estimators of the expected ordered failure times of the n components of the systems under study. These results lead to the identification of ε‐optimal systems relative to the chosen criterion function. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献