分层抽样中均值估计误差分布的随机加权逼近

本文讨论了分层抽样问题中各总体均值线性组合的估计误差及其T型统计量分布的随机加权逼近的收敛速度,在一定的条件下证明了其速度可达(?),其中n为样本总容量。     

分层抽样下的分别乘积估计和联合乘积估计

提出了分层抽样总体均值的分别乘积估计和联合乘积估计的概念，讨论了这两种估计量的性质，并对这两种估计量的优劣作了定性分析。     

基于部分分层抽样的高墩桥梁随机地震响应分析

为了表征桥梁结构不确定性和随机参数相关性对桥梁结构抗震性能的影响,从概率角度对桥梁进行抗震性能分析,基于部分分层抽样原理建立了时-频非平稳地震作用下桥梁非线性随机地震响应分析方法.基于地震动演化功率谱,采用谱表示方法生成非平稳地震动样本,并采用基于正交函数的思想对谱表示方法中的随机变量进行模拟,通过两个基本随机变量表征...     

分层抽样可有效保证审核样本的可靠性

审核的目的是为获得审核证据并对其进行客观评价,但是,在审核过程中,通常不可能检查到审核范围内所有的活动、操作、过程、文件或记录,而只能通过抽取的样本来证实相应的审核对象是否符合要求,使审核结论具有一定的风险     

基于部分分层抽样的高墩桥梁随机地震响应分析EI北大核心CSCD

为了表征桥梁结构不确定性和随机参数相关性对桥梁结构抗震性能的影响,从概率角度对桥梁进行抗震性能分析,基于部分分层抽样原理建立了时-频非平稳地震作用下桥梁非线性随机地震响应分析方法。基于地震动演化功率谱,采用谱表示方法生成非平稳地震动样本,并采用基于正交函数的思想对谱表示方法中的随机变量进行模拟,通过两个基本随机变量表征地震动的不确定性;采用基于数论的部分分层抽样方法对地震动-结构随机变量抽样,从而对桥梁非线性随机地震响应进行模拟,减小桥梁随机地震响应分析中的抽样方差;以一座实际高墩连续刚构桥为数值算例,对其进行了非线性随机地震响应分析,详细研究了桥梁结构不确定性和随机参数相关性对其地震可靠度的影响。研究结果表明:随机地震作用下,桥梁随机地震响应是典型的零均值非平稳随机过程,从地震动开始到结束,桥梁结构地震响应概率密度曲线存在由窄边宽,再由宽变窄的演化过程;随机地震作用下,桥梁结构关键响应的平均峰值因子存在一定差异,其通常在1.8~2.2变化;桥梁结构不确定性和随机参数相关性对高墩桥梁地震响应极值分布和地震可靠度的影响较为显著,忽略桥梁结构的不确定性和随机参数相关性将高估桥梁结构的地震可靠度。     

关于在产品质量核查检验中抽样检验标准的选用

本文通过对抽样检验的目的、程序和类型以及对国家最新发布的4项质量核查抽样标准的分析,阐述了在产品质量核查检验中如何正确选择抽样检验标准的重要性。     

浅析产品质量检验

本文主要论述了质量检验机构产品检验的基本职能、遵循的原则、具备的条件和检验步骤,提出了产品检验结果的质量控制方法。     

浅谈产品质量检验

本文主要论述了质量检验机构产品检验的基本职能、遵循的原则、具备的条件和检验步骤,提出了产品检验结果的质量控制方法。     

产品质量检验探析

固有的特性,满足需要的能力。产品质量检验,根据检验原理、条件、设备的不同的特点,分为感官检验法、物理检验法,化学检验法,微生物检验法和产品试验法。     

浅论产品质量检验

固有的特性,满足需要的能力。产品质量检验：根据检验原理、条件、设备的不同特点,分为感官检验法、物理检验法,化学检验法,微生物检验法和产品试验法。     

L-Moments Based Calibrated Variance Estimators Using Double Stratified Sampling

Variance is one of the most vital measures of dispersion widely employed in practical aspects. A commonly used approach for variance estimation is the traditional method of moments that is strongly influenced by the presence of extreme values, and thus its results cannot be relied on. Finding momentum from Koyuncu’s recent work, the present paper focuses first on proposing two classes of variance estimators based on linear moments (L-moments), and then employing them with auxiliary data under double stratified sampling to introduce a new class of calibration variance estimators using important properties of L-moments (L-location, L-cv, L-variance). Three populations are taken into account to assess the efficiency of the new estimators. The first and second populations are concerned with artificial data, and the third populations is concerned with real data. The percentage relative efficiency of the proposed estimators over existing ones is evaluated. In the presence of extreme values, our findings depict the superiority and high efficiency of the proposed classes over traditional classes. Hence, when auxiliary data is available along with extreme values, the proposed classes of estimators may be implemented in an extensive variety of sampling surveys.     

Minimum Average Total Inspection Plans for Variables Sampling, Indexed by Average Outgoing Quality Limit

Dodge and Romig's 1944 volume Sampling Inspection Tables provided, among other procedures, sampling inspection plans for attributes inspection which were indexed by average outgoing quality limit. These tabulated plans guaranteed that when rejected lots are appropriately treated, the long-term average outgoing product quality would not exceed the average outgoing quality limit (AOQL) index of the plan. In addition, the plans were structured so that when the submitted quality level was at the indicated level of process average, the total amount of inspection would be minimized. In this article, plans are presented that match the AOQL, lot size, and process average parameters of the Dodge and Romig plans, but are based on variables sampling rather than attributes sampling. It is assumed that the distribution of the measured characteristic is Normal. Although measurements data are usually more difficult to obtain than attributes data and more calculation is involved in using the plans, the sample sizes are generally substantially smaller. The exception to this is for unknown standard deviation plans, higher AOQL index, and process average near the listed AOQL. It would be presumed that in present-day applications, plans involving low levels of both process average and AOQL would be most widely used.     

配网重点物资采购抽检方案研究

针对现行配网物资采购抽检制度中存在的不同批量的产品事实上宽严程度不一致的问题,基于常用的MIL-STD-1916抽样标准,提出一种计数调整型的配网重点物资抽检方案。该抽检方案结合电网的抽检实际,在考虑科学性的基础上,兼顾电网抽检相关文件中规定的重点物资抽样检验4个“百分之百”的要求和(n|0)要求,且不加大现有抽检工作量。研究成果可以直接应用于配网物资采购抽检实际工作中。     

对产品抽样检验国家标准的探讨与研究

本文通过对抽样检验标准创立和我国统计抽样检验标准发展历程的深入探讨,以及对我国现行有效抽样检验国家标准主题内容和适用范围的综合分析,阐述了贯彻执行和正确使用抽样检验国家标准的重要性。     

Chain Sampling Scheme under Constant Inspection Errors

The primary aim of this paper is to extend the inspection error consideration to chain sampling schemes, an area that has not been dealt with in the literature. A mathematical model is developed to investigate the performance of chain sampling schemes under constant inspection errors. Expressions of performance measures, such as operating characteristic function, average total inspection and average outgoing quality, are derived to aid the analysis of a general chain sampling scheme, ChSP‐4A ( ) r, developed by Frishman. This study reveals that as Type I inspection error increases the probability of acceptance will decrease and as Type II inspection error increases the acceptance probability will increase. The effect of Type II error on the probability of acceptance is very marginal compared with that of Type I error, especially when the true fraction non‐conforming is small. In addition, the effects of inspection errors can be ‘eliminated’ by transforming to its equivalent perfect inspection counterpart, hence greatly reducing the complexity of the analysis. The effects of other sampling parameters are also studied to serve as a foundation for future plan designing purposes. Copyright © 2006 John Wiley & Sons, Ltd.     

定量包装中计量抽检方案的设计

从市场上抽取定量包装的商品进行检测时,经常碰到的问题是如何合理地抽取被检测的商品数量.文章将利用正态分布函数来讨论抽样方案的设计.     

产品质量抽样检验的两种风险分析

本文阐述了产品质量抽样检验中两种风险意义、数值计算方法及抽样方案中3个参数变化对它们的影响规律,对制定产品质量抽样检验方案有理论指导意义。     

解读GB/T28863-2012《商品质量监督抽样检验程序具有先验质量信息的情形》标准

新颁布的GB/T 28863-2012于2013年2月15日实施,专门针对流通环节商品的质量监督抽样检验程序,解决了流通环节商品的抽查成本高、监管效能较低下等问题,使监督检验结论的适用范围不再仅限于某一经营者或者某一批次不合格商品,有效提升了监管部门的抽检工作统筹管理,并有助于指导行业质量整改和提高。