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201.
Nader Ebrahimi 《海军后勤学研究》2005,52(1):46-57
Diffusion processes are commonly used to describe the dynamics of complex systems arising in a wide range of application fields. In this paper we propose, on the basis of diffusion processes, two models concerned with the stochastic behavior of fatigue cracks in a system. They are then used to get the distribution of the failure time, the first time the crack size of at least one of the cracks exceeds a given value. Several properties of our proposed models are presented, and the unknown parameters are estimated by the method of maximum likelihood. From these an estimate of failure time distribution is obtained. In this part, contrary to common practice, we do not assume availability of failure data. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005 相似文献
202.
A. Gmez‐Corral 《海军后勤学研究》2004,51(8):1068-1089
The model considered in this paper involves a tandem queue consisting of a sequence of two waiting lines. The main feature of our model is blocking, i.e., as soon as the second waiting line reaches a certain upper limit, the first line is blocked. The input of units to the tandem queue is the MAP (Markovian arrival process), and service requirements are of phase type. Our objective is to study the sojourn time distribution under the first‐come‐first‐serve discipline by analyzing the sojourn time through times until absorption in appropriately defined quasi‐birth‐and‐death processes and continuous‐time Markov chains. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004 相似文献
203.
星载InSAR(干涉式合成孔径雷达)在对地观测任务中具有广泛的应用,其空间基线随卫星编队平台的运动而变化。本文基于卫星编队的构形原理,定义了星载InSAR均匀相位构形。根据干涉测量原理定义了相关基线及其稳定度,研究了不同均匀相位构形下星载InSAR的基线稳定性。 相似文献
204.
As a main oxidizer in solid composite propellants, ammonium perchlorate (AP) plays an important role because its thermal decomposition behavior has a direct influence on the characteristic of solid com-posite propellants. To improve the performance of solid composite propellant, it is necessary to take measures to modify the thermal decomposition behavior of AP. In recent years, transition metal oxides and carbon-supported transition metal oxides have drawn considerable attention due to their extraor-dinary catalytic activity. In this review, we highlight strategies to enhance the thermal decomposition of AP by tuning morphology, varying the types of metal ion, and coupling with carbon analogue. The enhanced catalytic performance can be ascribed to synergistic effect, increased surface area, more exposed active sites, and accelerated electron transportation and so on. The mechanism of AP decom-position mixed with catalyst has also been briefly summarized. Finally, a conclusive outlook and possible research directions are suggested to address challenges such as lacking practical application in actual formulation of solid composite propellant and batch manufacturing. 相似文献
205.
制作了压电位相调制器 ,并利用光纤干涉仪测量了它的相移系数 ,同时对影响它的相移能力的几个因素进行了实验和理论分析 ,为研制干涉型光纤传感器做准备 . 相似文献
206.
平板湍流边界层内气泡流流动实验研究 总被引:1,自引:0,他引:1
在低湍流度水槽里 ,利用片光源显示了平板气液两相湍流边界层内气泡流的流场结构 ,研究了平板安装位置、来流速度、喷气方式等参数对湍流边界层内气泡流的影响 .利用激光测速技术测量了平板水平放置时气泡流最外缘处的水平速度及厚度 .结果表明 :平板喷气减阻的原因在于喷气改变了平板湍流边界层的流动结构 ,抑制了湍流 相似文献
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随着时钟频率的增加以及电源电压的降低,电源完整性问题日益凸显。将电流变化率加入到最差噪声算法的电流约束中,能够在任意电流变化率的情况下分析电源分布网络的最差噪声,从而获得更加真实的最差噪声。另外,利用改进的Knuth-Yao四边形不等式法对基于动态规划的最差噪声算法进行加速,加速后算法的时间复杂度从O(n~2m)降为O(mnlogn)。 相似文献