共查询到14条相似文献,搜索用时 109 毫秒
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在以能力验证为目的的实验室间比对活动中,指定值(参考值)的确定是一个非常重要的环节.本文给出了指定值(参考值)几种不同的确定方式,分析了如何运用一定的统计方法,对实验室间比对的能力验证数据进行处理. 相似文献
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实验室间比对结果统计处理采用方法的比较分析 总被引:1,自引:0,他引:1
董芳 《现代测量与实验室管理》2009,17(4):57-59,50
对两种实验室间比对试验结果统计处理方法进行比较分析,认为两种方法各有优势,Z比分数稳健统计法适用于对单样品或样品对的实验室间比对和实验室内比对结果的评价,缺点是当试验结果比较对称时,Z值计算会出现分母为零的情况。h值检验法适用于任何只要试验结果是以数值形式表示的实验室间比对的统计;实践表明,两种方法所统计的参考值基本可以相互替代;采用任何一种方法对试验结果进行评价时,以参照试验方法精密度要求为宜。 相似文献
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D. del Campo D. Amil P. Hernández M. A. Castellanos J. Cordero M. Entrena N. de Castro R. Jiménez J. L. Lucena A. Pereda L. Pérez M. Prats P. Quintana L. Quintanilla R. Ríos J. J. Segovia F. Yebra 《International Journal of Thermophysics》2014,35(6-7):1239-1250
Sterilization autoclaves are devices used to sterilize equipment and supplies; their users require a periodic determination of their performance to ensure that the required temperature is reached and maintained for the predefined time interval. Within the ENAC (Entidad Nacional de Acreditación, Spanish national accreditation body) Temperature and Humidity Technical Subcommittee, it was decided to carry out an inter-laboratory comparison on the characterization of sterilization autoclaves aiming to demonstrate the equivalence among the test procedures of the different participants. This paper presents the data processing and the results of this comparison that showed some discrepancies in the stability and uniformity measurements due to different parameter definitions and a probable underestimation of some uncertainty sources. The results show good agreement among the participants in the estimation of the set-point correction, while the estimation of the device stability and uniformity was not compatible in some cases. The use of wired or wireless sensors did not bias the results, but the laboratories that used pt-100 obtained results that underestimated the value of the thermal stability, probably due to their higher thermal mass and response time. 相似文献
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Density Estimation for Statistics and Data Analysis 总被引:1,自引:0,他引:1
Khosrow Dehnad 《技术计量学》2013,55(4)
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Kenneth D. Kotnour 《技术计量学》2013,55(4):460-461
As an alternative to traditional life testing, degradation tests can be effective in assessing product reliability when measurements of degradation leading to failure can be observed. This article presents a degradation model for highly reliable light displays, such as plasma display panels and vacuum fluorescent displays (VFDs). Standard degradation models fail to capture the burn-in characteristics of VFDs, when emitted light actually increases up to a certain point in time before it decreases (or degrades) continuously. Random coefficients are used to model this phenomenon in a nonlinear way, which allows for a nonmonotonic degradation path. In many situations, the relative efficiency of the lifetime estimate is improved over the standard estimators based on transformed linear models. 相似文献
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油料发射光谱分析被广泛地应用于检测润滑油中磨损金属含量、污染物种类、添加剂衰变等,在机械设备的状态监测与故障诊断中起着不可替代的作用.为确保油料发射光谱仪分析数据的可信性和共享性,配制了3种不同元素含量的检测油样,对分布在北纬18°至北纬41°之间的10个实验室的油料发射光谱仪进行比对实验,运用Z比分数法和均方根法对实验得到的数据进行分析评价,并提出了均方根法的评价标准.比对分析表明:在仪器的重复性方面,Z比分数法不能对仪器进行评价,均方根法判断准确率为88.9%,漏判率为11.1%,没有误判;在仪器的精确度性能上,Z比分数法判断准确率为33.3%.漏判率为66.7%,误判率为13.3%,均方根法判断准确率为80%,漏判率为20%,没有误判. 相似文献
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