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81.
介绍了寿命周期费用(LCC)分析的基本概念及操作程序,给出了武器装备寿命周期费用的一般构成体系,讨论了LCC分析在武器装备应用中需要注意的问题,并对其未来发展方向作了展望.  相似文献   
82.
陶渊明所处的魏晋时期是人的生命意识和生命情绪全面觉醒的时期,生命成为人们关注的对象,从陶渊明的生命价值、生命真谛和生命信仰来探讨他的自然观,进而表现陶渊明对生命意识的独特解读。  相似文献   
83.
针对加权核范数最小化算法存在结构残余噪声以及无法较好地保持图像边缘结构的问题,提出基于加权核范数最小化和改进小波阈值函数的图像去噪算法。利用全变分模型对噪声图像进行初步去噪,使用噪声图像与初步去噪后的图像进行差分运算,对差分后得到的噪声残差图像使用改进的小波阈值函数去噪,将小波去噪后的残差图像与初步去噪图像叠加,将叠加后的图像使用基于残余噪声水平迭代的加权核范数最小化算法进行二次去噪。相较于当下主流去噪算法,经该算法处理后的图像的PSNR和SSIM值均有所提升,能够更好地保持图像的纹理结构,且在高噪声环境下效果更佳。  相似文献   
84.
由于工作原理不同,舰炮使用传统无控弹试射方法不适用于一维弹道修正弹。分析了舰炮使用一维弹道修正弹射击误差构成和试射的必要性,提出了一维弹道修正弹校正射击诸元误差和预测误差试射新方法。首先通过分析对海射击以实际观测弹着水柱与提前点偏差作为发射诸元误差的精度,以及以预测弹着落点与实际观测弹着水柱偏差作为预测误差的精度,提出了求取诸元误差和预测误差的方法,论证了试射发数;然后从距离上和方向上校正诸元误差和预测误差。假设各误差值,通过仿真计算表明,按新方法试射能够显著提高射击精度。  相似文献   
85.
The empirical international conflict literature has given much recent attention to interstate armed force’s impact on human well-being. While empirical research has advanced our understanding of the phenomenon considerably, we argue that one conclusion that many studies have reached is preliminary. Some recent research contends that only full-scale war, and not force short of war, has a discernable impact on human welfare or physical quality of life (PQOL). We develop theory on one type of force short of war, large-scale foreign military intervention (FMI), and its potential effects on PQOL. Using interrupted time series and panel corrected standard error methodologies, we find that from 1960 to 2005 large-scale FMI had a statistically and substantively significant impact on the PQOL of populations in 106 developing countries. The specific effect that this type of armed force has depended in large part on the regime type of the target country.  相似文献   
86.
We consider a three‐layer supply chain with a manufacturer, a reseller, and a sales agent. The demand is stochastically determined by the random market condition and the sales agent's private effort level. Although the manufacturer is uninformed about the market condition, the reseller and the sales agent conduct demand forecasting and generate private demand signals. Under this framework with two levels of adverse selection intertwined with moral hazard, we study the impact of the reseller's and the sales agent's forecasting accuracy on the profitability of each member. We show that the manufacturer's profitability is convex on the reseller's forecasting accuracy. From the manufacturer's perspective, typically improving the reseller's accuracy is detrimental when the accuracy is low but is beneficial when it is high. We identify the concrete interrelation among the manufacturer‐optimal reseller's accuracy, the volatility of the market condition, and the sales agent's accuracy. Finally, the manufacturer's interest may be aligned with the reseller's when only the reseller can choose her accuracy; this alignment is never possible when both downstream players have the discretion to choose their accuracy. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 207–222, 2014  相似文献   
87.
Many conventional models that characterize the reliability of multicomponent systems are developed on the premise that for a given system, the failures of its components are independent. Although this facilitates mathematical tractability, it may constitute a significant departure from what really takes place. In many real‐world applications, system components exhibit various degrees of interdependencies, which present significant challenges in predicting degradation performance and the remaining lifetimes of the individual components as well as the system at large. We focus on modeling the performance of interdependent components of networked systems that exhibit interactive degradation processes. Specifically, we focus on how the performance level of one component affects the degradation rates of other dependent components. This is achieved by using stochastic models to characterize how degradation‐based sensor signals associated with the components evolve over time. We consider “Continuous‐Type” component interactions that occur continuously over time. This type of degradation interaction exists in many applications, in which interdependencies occur on a continuum. We use a system of stochastic differential equations to capture such “Continuous‐Type” interaction. In addition, we utilize a Bayesian approach to update the proposed model using real‐time sensor signals observed in the field and provide more accurate estimation of component residual lifetimes. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 286–303, 2014  相似文献   
88.
随机滤波模型在变速箱剩余寿命预测中的应用研究   总被引:1,自引:0,他引:1  
摘要:基于变速箱加速寿命实验的振动信号,提取信号的多种特征参量.通过分析各特征参量的敏感性和稳定性,选择幅域裕度指标、峰值指标、波形指标和RMS(RootMeanSquare)作为特征参量,建立一种基于随机滤波的变速箱剩余寿命预测模型,给出剩余寿命后验概率密度的递推公式,设计了极大似然估计方法求解模型参数,并经实例验证模型的有效性和实用性.  相似文献   
89.
介绍步进应力加速寿命试验原理,通过对制导弹药自动导引头贮存状态和失效机理的分析,确定了加速寿命试验应力和应力水平.假设产品寿命服从威布尔分布,应用极大似然估计和Bayes的方法处理数据,建立制导弹药可靠储存寿命预测模型,并计算得到自动导引头在正常应力水平下的可靠储存寿命.  相似文献   
90.
本研究对新疆在校大学生生活价值观现状及应对方式进行调研,经分析得出:新疆高校大学生生活价值观各维度与积极应对呈线性相关,不向学生的生活价值观在年级、专业、性别变量上存在显著差异和多样性,农学专业学生在生活价值观各维度和压力应对上需要进一步引导和关注。  相似文献   
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