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区间统计量及其分布 被引量:12
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作者 傅惠民 《机械强度》 EI CAS CSCD 北大核心 2005年第6期752-757,共6页
提出区间统计量和区间秩统计量的概念,建立其概率密度函数和联合分布函数,给出区间统计量的均值、方差、协方差和区间秩统计量的平均秩、中位秩、百分位秩计算公式。区间统计量是对顺序统计量的补充,当失效数据较少难以统计分析时,可以... 提出区间统计量和区间秩统计量的概念,建立其概率密度函数和联合分布函数,给出区间统计量的均值、方差、协方差和区间秩统计量的平均秩、中位秩、百分位秩计算公式。区间统计量是对顺序统计量的补充,当失效数据较少难以统计分析时,可以通过区间统计量增加其数据,提高统计分析的精度。在此基础上,提出一种区间数据最佳线性无偏估计方法,并对正态分布、极值分布、Weibull分布等常用的位置—尺度分布进行讨论,该方法能够对产品贮存寿命进行小样本预测和可靠性评定。 展开更多
关键词 区间统计量 区间统计 顺序统计 统计 区间数据 最佳线性无偏估计 贮存寿命 可靠性小样本
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Application of Two-Order Difference to Gap Statistic
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作者 岳士弘 王秀秀 魏苗苗 《Transactions of Tianjin University》 EI CAS 2008年第3期217-221,共5页
Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, ... Gap statistic is a well-known index of clustering validity, but its realization is difficult to be comprehended and accurately determined. A direct method is presented to improve the performance of the Gap statistic, which applies the two-order difference of within-cluster dispersion to replace the constructed null reference distribution in the Gap statistic. Hence, the realization of the Gap statistic becomes easy and is reformulated, and its uncertainty in applications is reduced. Also, the limitation of the Gap statistic is analyzed by two typical examples, that is, the Gap statistic is difficult to be applied to the dataset that contains strong-overlap or uneven-density clusters. Experiments verify the usefulness of the proposed method. 展开更多
关键词 clustering validity Gap statistic data structure
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离子推力器极少数据可靠性评估方法 被引量:5
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作者 李军星 张勇波 +1 位作者 傅惠民 王治华 《航空动力学报》 EI CAS CSCD 北大核心 2015年第10期2352-2356,共5页
针对只有两台离子推力器进行寿命试验,试验结果为极少失效数据的情况,建立了一种离子推力器整机可靠性评估方法.通过引入区间统计量的概念,充分开发从最后一个失效数据继续试验到没有发生产品失效这一重要试验信息,由高斯-马尔科夫定理... 针对只有两台离子推力器进行寿命试验,试验结果为极少失效数据的情况,建立了一种离子推力器整机可靠性评估方法.通过引入区间统计量的概念,充分开发从最后一个失效数据继续试验到没有发生产品失效这一重要试验信息,由高斯-马尔科夫定理计算出寿命分布参数的最佳线性无偏估计,并给出离子推力器可靠度和寿命的单侧置信下限.最后,对美国NASA研制的型号为XIPS-13的离子推力器进行可靠性评估,得出了其寿命需求10000h的可靠度单侧置信下限为0.87及给定可靠度为0.9时的寿命单侧置信下限为9 024.6h,该方法精度较高,便于工程应用. 展开更多
关键词 离子推力器 可靠性评估 极少失效数据 区间统计量 WEIBULL分布
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GENERALIZED p-VALUES AND GENERALIZED CONFIDENCE INTERVALS FOR VARIANCE COMPONENTS IN GENERAL RANDOM EFFECT MODEL WITH BALANCED DATA 被引量:9
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作者 Rendao YE Songgui WANG 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2007年第4期572-584,共13页
Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In thi... Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In this paper, we mainly consider these problems in general random effect model with balanced data. Exact tests and confidence intervals for a single variance component corresponding to random effect are developed by using generalized p-values and generalized confidence intervals. The resulting procedures are easy to compute and are applicable to small samples. Exact tests and confidence intervals are also established for comparing the random-effects variance components and the sum of random-effects variance components in two independent general random effect models with balanced data. Furthermore, we investigate the statistical properties of the resulting tests. Finally, some simulation results on the type Ⅰ error probability and power of the proposed test are reported. The simulation results indicate that exact test is extremely satisfactory for controlling type Ⅰ error probability. 展开更多
关键词 Generalized confidence interval generalized p-value variance component.
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