仪器误差符合性测试中的风险控制方法

在仪器误差符合性测试过程中,需要通过测量结果给出被测仪器设备合格与否的判定。由于测量不确定度的存在,会导致误判的可能,从而给用户和厂家带来决策风险。为了确保厂家风险（PR）及用户风险(CR)可控,提出了过程能力指数(PCI)、测试不确定度比(TUR)、保护带允许误差比(GTR)综合控制方法,建立了这3个参数与厂家风险和用户风险间的关系,并通过图形化方式给出了实际测试过程风险控制准则。仿真结果表明,在一定的过程能力指数下,选择适当的不确定度比和置信区间保护带,可以满足CR和PR期望值要求。     

Bayesian methodology for reliability model acceptance

This paper develops a methodology to assess the reliability computation model validity using the concept of Bayesian hypothesis testing, by comparing the model prediction and experimental observation, when there is only one computational model available to evaluate system behavior. Time-independent and time-dependent problems are investigated, with consideration of both cases: with and without statistical uncertainty in the model. The case of time-independent failure probability prediction with no statistical uncertainty is a straightforward application of Bayesian hypothesis testing. However, for the life prediction (time-dependent reliability) problem, a new methodology is developed in this paper to make the same Bayesian hypothesis testing concept applicable. With the existence of statistical uncertainty in the model, in addition to the application of a predictor estimator of the Bayes factor, the uncertainty in the Bayes factor is explicitly quantified through treating it as a random variable and calculating the probability that it exceeds a specified value. The developed method provides a rational criterion to decision-makers for the acceptance or rejection of the computational model.     

扩展不确定度分析与评定

ISO《测量不确定度表示指南》给出两种选择包含因子的方法 :韦尔奇 -萨特思韦特公式法和简便方法 .文章据此对扩展不确定度的影响因素进行分析 ,并针对使用简便方法引起的包含因子的误差、不确定度以及扩展不确定度的不确定度进行分析和评定 ,以阐明有效自由度对包含因子和扩展不确定度的影响     

自动调整臂寿命检测与评价系统

基于PLC(可编程逻辑控制器)与MCGS(监视与控制通用系统)组态软件,设计了自动调整臂寿命测试系统.从疲劳试验机的示值不确定度、由标定方给出的相对扩展不确定度、计数器校准时校准源引入的相对扩展不确定度三个方面,合成了疲劳性能的合成相对标准不确定度并转化成绝对不确定度,再使用不确定度评定自动调整臂的寿命.系统能够实现智能控制,记录表征自动调整臂寿命的运转次数.在实际应用中该测试系统运行稳定,不确定度评定方式有助于提高自动调整臂质量.     

Decision making with epistemic uncertainty under safety constraints: An application to seismic design

The problem of accounting for epistemic uncertainty in risk management decisions is conceptually straightforward, but is riddled with practical difficulties. Simple approximations are often used whereby future variations in epistemic uncertainty are ignored or worst-case scenarios are postulated. These strategies tend to produce sub-optimal decisions. We develop a general framework based on Bayesian decision theory and exemplify it for the case of seismic design of buildings. When temporal fluctuations of the epistemic uncertainties and regulatory safety constraints are included, the optimal level of seismic protection exceeds the normative level at the time of construction. Optimal Bayesian decisions do not depend on the aleatory or epistemic nature of the uncertainties, but only on the total (epistemic plus aleatory) uncertainty and how that total uncertainty varies randomly during the lifetime of the project.     

融合生产信息的产品检验不确定度评定

为合理减小测量不确定度对产品合格判定的影响,研究融合生产信息的产品检验不确定度评定。建立融合加工信息和测量信息的贝叶斯信息融合模型,基于被测参数后验分布对测量结果及其不确定度进行重新估计,依据信息融合后的结果进行产品合格判定;提出利用质量控制信息计算贝叶斯先验参数的方法。仿真实验和实例分析结果表明,在产品检验不确定度评定中融入生产信息,可有效扩大产品检验合格区,合理减小合格判定的工作量。     

液相色谱-串联质谱法测定动物性食品中万古霉素残留的不确定度评定

本文对液相色谱-质谱联用法测定动物源性食品中万古霉素含量过程中可能引入的不确定度进行了分析和评定。该过程中测量不确定度主要来源于样品处理引入的不确定度、标准曲线拟合引入的不确定度、重复性测量引入的不确定度等。本文对各不确定度量进行了评定,计算了合成不确定度和扩展不确定度。     

GUM与基于观测方程的测量不确定度评估

比较了GUM系列文件与贝叶斯方法评估不确定度的过程,说明GUM是以测量方程为基础的前向分析方法,而贝叶斯分析是以观测方程为基础、以数据分析为主的一种后向不确定度评估方法。运用概率模型的描述方法对上述两种分析过程进行了分析与比较,说明了两种方法在线性测量模型的条件下,不考虑被测量先验分布时两种结果基本一致,对于非线性的测量模型,GUM S1得到的结果与一定先验分布条件下的贝叶斯分析的结果也基本一致。最后通过实例说明了该结论。     

检定立式金属罐容量测量不确定度的研究

本文结合立式金属罐的容量测量实例，详述了标准不确定度的计算及扩展不确定度的获得过程。     

Comparison of evidence theory and Bayesian theory for uncertainty modeling

This paper compares Evidence Theory (ET) and Bayesian Theory (BT) for uncertainty modeling and decision under uncertainty, when the evidence about uncertainty is imprecise. The basic concepts of ET and BT are introduced and the ways these theories model uncertainties, propagate them through systems and assess the safety of these systems are presented. ET and BT approaches are demonstrated and compared on challenge problems involving an algebraic function whose input variables are uncertain. The evidence about the input variables consists of intervals provided by experts. It is recommended that a decision-maker compute both the Bayesian probabilities of the outcomes of alternative actions and their plausibility and belief measures when evidence about uncertainty is imprecise, because this helps assess the importance of imprecision and the value of additional information. Finally, the paper presents and demonstrates a method for testing approaches for decision under uncertainty in terms of their effectiveness in making decisions.     

LC-MS法测定动物源性食品中抗生素残留的不确定度评定

液相色谱-质谱联用法测定动物源性食品中抗生素类化合物的不确定度来源,主要有样品处理过程引入的不确定度、标准曲线拟合引入的不确定度、重复性测量引入的不确定度等.本文对各不确定度量进行了评定,计算了合成不确定度和扩展不确定度.     

定型隔热制品导热系数（水流量平板法）不确定度的评定

介绍了定型隔热制品导热系数（水流量平板法）不确定度的要素构成及各类不确定度分量的计算方法,并计算了各不确定度分量的自由度,得出合成不确定度和扩展不确定度。得到不确定度报告为：导热系数检测结果A=0．197W／（m·K）,扩展不确定度U=0．005W／（m·K）,包含因子k=2。     

A novel Bayesian strategy for the identification of spatially varying material properties and model validation: an application to static elastography

The present paper proposes a novel Bayesian, a computational strategy in the context of model‐based inverse problems in elastostatics. On one hand, we attempt to provide probabilistic estimates of the material properties and their spatial variability that account for the various sources of uncertainty. On the other hand, we attempt to address the question of model fidelity in relation to the experimental reality and particularly in the context of the material constitutive law adopted. This is especially important in biomedical settings when the inferred material properties will be used to make decisions/diagnoses. We propose an expanded parametrization that enables the quantification of model discrepancies in addition to the constitutive parameters. We propose scalable computational strategies for carrying out inference and learning tasks and demonstrate their effectiveness in numerical examples with noiseless and noisy synthetic data. Copyright © 2012 John Wiley & Sons, Ltd.     

辉光放电质谱仪测定不锈钢中微量元素的不确定度分析

本文以不锈钢中铁(Fe)元素作为内标,采用辉光放电质谱仪测定不锈钢中锰(Mn),硅(Si),硫(S),磷(P),镍(Ni),铬(Cr),钨(W),钒(V),钼(Mo),铝(Al),钛(Ti),铜(Cu)等12种元素。讨论了测试过程中由测量重复性、样品不均匀性和标准样品本身不确定度等因素所带来的不确定度分量,计算出测定不锈钢中的12种元素百分含量的合成不确定度及扩展不确定度。研究结果表明,采用辉光放电质谱仪测定不锈钢中的12种元素含量的扩展不确定度均小于0.01%。     

用MC仿真计算不确定度

介绍MC仿真的基础,将它用于不确定度的分布传播,并作了扩展不确定度的算法验证.     

Three Types of Mathematical Uncertainty Models

Mathematical models have been constructed for three types of uncertainty (interval, stochastic, and Bayesian), and the application of these models is discussed for describing measurements in the presence of unmonitored fluctuations leading to ambiguities in the results. __________ Translated from Izmeritel'naya Tekhnika, No. 9, pp. 39–44, September, 2005.     

基于贝叶斯理论的测量不确定度A类评定

文章介绍了贝叶斯理论，并利用此理论对测量不确定度A类评定进行分析，与基于经典统计方法的不确定度A类评定相比，该方法能充分利用历史测量数据所提供的信息，因此评定时信息量大，使评定更加合理。最后通过实例分析说明了基于贝叶斯理论的不确定度A类评定的合理性和优越性。     

LC-MS/MS测定猪尿中盐酸克伦特罗不确定度的评定

建立了液相色谱-串联质谱法(LC-MS/MS)测定猪尿中盐酸克伦特罗残留量的不确定度评定数学模型,分析了影响样品测定结果的不确定度的主要来源,并计算出了各影响因素的不确定度分量.当猪尿中盐酸克伦特罗残留量的测定结果为3.6ng/mL时,其扩展不确定度为0.4ng/mL.     

喷嘴式空气流量测量不确定度分析与评定

为了解可直接测量参数对喷嘴式空气流量测量结果准确性及可靠程度的影响,找出对测试结果影响较大的环节以进行提高测量准确度的改进,建立喷嘴式空气流量测量数学模型,分别对测试喷嘴处空气比容和测试喷嘴前后气体静压差引入的不确定度进行分析,对喷嘴式空气流量测量进行合成标准不确定度评定和扩展不确定度评定。结果表明：测试空气质量流量为0．119kg／s时,合成标准不确定度为2．396×10kg／s,扩展不确定度为1．433×10^-3kg／s,测试相对误差为1．20％,其中测试喷嘴前后气体静压差引入的不确定度较大,提出选用量程为0～500Pa的差压变送器较为适宜。     

基于预测模型的虚拟试验不确定性分析方法

 工程系统中不可避免地存在各种参数不确定性,利用数值计算模型对系统进行虚拟试验时应进行不确定性分析.大型耗时计算模型的不确定性分析将面临严重的的计算复杂性问题,为此,针对工程应用中耗时计算模型,提出一种基于贝叶斯预测模型的不确定性分析仿真方法,采用概率分布为参数不确定性建模,研究系统响应预测不确定性的概率特征.泰勒杆撞击实例验证了该方法的高效性.