共查询到18条相似文献,搜索用时 93 毫秒
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可靠性评估领域中环境因子的研究进展 总被引:5,自引:0,他引:5
论述了环境因子在可靠性评估领域的重要性,基于研究环境因子的3个前提,讨论了各类分布环境因子的定义。重点综述了国内环境因子的研究情况和所取得的成果,最后根据可靠性评估理论的发展方向和小子样理论在可靠性评估领域中的重要性,指出了对环境因子的确定方法进一步研究的必要性和方向。 相似文献
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指数分布环境因子的Bayes算法 总被引:2,自引:1,他引:1
对不同环境下指数分布环境因子的计算方法进行了讨论,并给出了检验指数分布有效性的统计方法。基于信仰推断的理论,得出环境因子的先验分布,进而对环境因子进行Dayes估计。最后运用仿真实例验证了该方法的有效性。 相似文献
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环境因子在电子产品可靠性评定中的应用研究 总被引:1,自引:0,他引:1
甄昕 《电子产品可靠性与环境试验》2009,27(1):20-22
在电子产品的可靠性评定过程中,应用环境因子折算方法可以利用不同环境下的可靠性数据,从而增加产品可靠性数据来源。通过阐述环境因子的定义,给出了电子产品的环境因子折算方法及应用实例。 相似文献
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环境因子在机载电子信息系统试飞试验可靠性评估的应用 总被引:1,自引:0,他引:1
机载电子信息系统在外场试飞试验中受到空中和地面两种不同的环境应力,针对以前可靠性评估中没有引入环境因子的问题,依据相关文献,给出了环境因子的工程计算方法;利用已有的外场试飞试验数据,对该电子信息系统外场试飞试验的环境因子进行了确定,并对环境因子应用于可靠性评估前后的结果进行了比较,表明在可靠性评估中引入环境因子,可以节省试验时间. 相似文献
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异步电动机节电器的智能控制方法 总被引:2,自引:0,他引:2
所介绍的智能控制方法,利用了模糊控制代替传统的PID等控制,可以较好地解决由于对象模型的不确定性而引起的困难。引入专家系统对模糊控制的量化因子和比例因子实行智能调整,使节电器在不同运行环境下部参产生很好的节电效果并具有良好的控制性能。 相似文献
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在室内这种特定环境下,无线信号在传播过程中会发生 NLOS 和 LOS 传播,由此产生定位误差。主要在 WIFI 无线网络环境下对室内定位精确度的影响因子 NLOS 和 LOS 进行研究,并在室内环境下的对信号传播模型进行建模。通过仿真定位环境,分析推导出在影响因子强度不同的室内环境下的两种影响因子消减优化算法 BRBF 和 V-OBTL 以及这两种优化算法在定位中的精确度,以此提出在不同影响因子环境中以及采用不同采样方式下的提高定位精度的方法。 相似文献
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环境数据综合方法是解决大型复杂电子产品性能可靠性评估中小子样问题的有效途径之一.而环境数据综合的关键在于确定各技术状态下的环境因子.现有的环境因子估计法存在估计精度低、物理建模难等问题,因而限制了其工程应用.为此,提出了一种基于电路仿真的环境因子估计法.该方法首先绘制出产品的Pspice电路原理图(相当于物理建模),而后运用软件的瞬态分析、Monte-Carlo分析和温度分析获取各环境状态下的性能仿真数据,再结合加速性能试验的有关理论,即可实现任意环境下环境因子的估计.最后,以某型装备上的稳压电源为例说明了该方法的有效性和实用性. 相似文献
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Two definitions of environmental factors for the inverse Gaussian distribution are proposed here. From the second definition the upper and lower confidence limits of the inverse Gaussian environmental factor are derived by a classical method. Based on the first definition the Bayes limits of the inverse Gaussian environmental factor are also given using non-informative reference prior as well as the natural conjugate prior. An application example is provided. 相似文献
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An environmental factor converts reliability test results at one environmental condition into equivalent “failure” information at other environments. This paper studies environmental-factor estimation for the binomial distribution. Under general conditions, Bayes point estimates and credibility limits for environmental factors are derived. Classical point and confidence interval estimates are introduced and compared with the Bayes estimators. The characteristics of Bayes and classical estimators for the binomial distribution are summarized through numerical computation and theoretical analysis. A numerical example of reliability assessment by means of environmental factors is presented 相似文献
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F. Hofbauer ÖVE G. Praxl ÖVE R. Draxler ÖVE 《e & i Elektrotechnik und Informationstechnik》1997,114(11):671-677
High voltage transmission lines are the subject of increasing public opposition. Environmental issues have become an important factor for utility companies, governments, standardisation organisations and local authorities. In this situation environmental management and more active public communication will have to play a significant role. The realisation of environmental management systems (EMS) for overhead power lines is discussed with regard to system boundaries and operation conditions. Based on standard EN ISO 14001 a model of an environmental management system manual for a high-voltage grid company is developed. Environmental information systems, environmental index values and the importance of EMS for rights-of-way management are discussed and solutions are proposed. 相似文献
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Environmental factor estimation for the gamma distribution with two parameters is considered here. In the consideration of the characteristics of the gamma distribution, the definition of environmental factors for the exponential distribution and the convenience of data conversion, the definition of environmental factors for the gamma distribution is proposed. In accordance with this definition, the lower and upper confidence limits of environmental factors are derived by Classical, Bayesian and Fiducial methods. Some approximate confidence limits are also given. A practical example is provided and the results indicate that the definition, the confidence limits and their approximants are suitable. 相似文献
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多功能环境模拟试验舱为可模拟各种环境因子(包括温湿度、换气率、压力、风速、光照等),试验人员可进行舱外操作试验,全过程电脑监控的密闭可视试验室。可进行生命体暴露、污染物挥发、净化产品性能检测、环境因素影响分析等实验。对国内外与室内空气品质有关的检测规范中提及的模拟现场试验舱进行分类,方便使用者与建造者之间的技术沟通。 相似文献
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CMOS-MEMS resonators are the key parts of modern integrated systems. Most of these resonators are fabricated through CMOS composite layers that are sensitive to temperature. In this article, the effects of temperature on the collective Young's moduli and quality factor of CMOS composite layers based MEMS resonator are theoretically modelled and experimentally validated. A custom made environmental chamber is used to control the environmental effects and an external vibration shaker is used to actuate the fabricated CMOS-MEMS resonator at its resonance frequency in the presence of a permanent magnet. Variations with increasing temperature in the collective Young's moduli of the CMOS composite layers are determined through the measurement of change in resonance frequency of the resonator and found to be linear. A nonlinear behaviour of the quality factor is noticed in the temperature range of 25 °C to 80 °C, the quality factor is found to be increasing whereas from 60 ∘ C to 80 ∘ C, the quality factor is decreasing. 相似文献