分析测试中的测量不确定度及评定 第二部分 测量不确定度评定的基本方法

本文叙述了测量不确定度评定的基本程序,A类和B类标准不确定度、合成标准不确定度和扩展不确定度评定的基本方法。     

分析测试中测量不确定度及评定 第五部分 测量不确定度评定中要注意的一些问题

对A类和B类不确定度评定的概念、合成标准不确定度的评定方法、温度对溶液体积的影响等几个容易混淆和在评定中要注意的问题进一步讨论,提出一些新的认识,有助于对测量不确定度评定概念的理解,并对评定中的具体问题作出正确、合理的判断。     

检定／校准实验室常用测量不确定度评定方法

本文提供了检定／校准实验室编制测量不确定度评定报告的一般评定步骤，以及常用测量不确定度评定方法。包括建立数学模型，标准不确定度A类、B类评定的方法，有效自由度、扩展不确定度的计算．以及不确定度报告的表示方法。     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

布氏硬度试验中测量的不确定度评定

文章介绍了布氏硬度试验中测量结果的不确定度评定方法。按标准硬度块示值误差、布氏硬度计、测量示值误差等不同因素,对不同范围的布氏硬度值进行不确定度评定。此次给出的布氏硬度试验测量结果的不确定度评定适用于本部门的布氏硬度试验。     

拉伸试验中测量的不确定度评定

介绍拉伸试验中测量结果的不确定度评定方法。依据测量不确定度的七个评定步骤，按不同的试样形状、尺寸，试验人员、尺寸测量器具、试验机等级、引伸计等级、拉伸速度等影响因素分别给出拉伸试验中的强度指标RP、ReH、ReL、Rt、Rm，与塑性指标A、Z测量结果的不确定度评定。此次给出的拉伸试验中测量结果的不确定度评定适用于本部门拉伸试验，可按试验时所用的试样形状、尺寸、测量器具、试验机、引伸计等条件选用不确定度的评定结果。     

电工圆铜线抗拉强度的测量不确定度评定研究

阐述测量不确定度的来源、定义及其评定的重要意义。对TY-3．0电工圆铜线的抗拉强度测量不确定度进行分析和评定,计算出各种因素的标准不确定度,得出抗拉强度的扩展不确定度,并给出最终测量结果的表达式。     

拉伸试验测量不确定度的评定

对测量不确定度的基本概念作了简单介绍．介绍了测最不确定度A类和B类评定的评定方法，井具体计算出拉伸试验的测罱不确定度．为实验室的检测项目进行测量不确定度的评定提供了参考。     

化学成分测量不确定度的评定

叙述了不确定度的发展及重要意义、基本术语及有关术语 ;介绍了测量化学成分时不确定度的来源和不确定度的评定过程 ,并举例说明。     

重量法测煤中灰分测量不确定度评定的探讨

对煤灰分的测量结果标准不确定度、扩展不确定度及不确定度表述进行了系统的分析和评定,并编写了相应的计算程序,对测量结果不确定度评定中的建模、分量计算、合成标准不确定度、扩展不确定度的评定和计算方面作了有益的尝试。描述了影响煤灰分测定结果各分量对其不确定度的相对贡献。     

The standard problem: Meaning and values in measurement and evaluation.

Discusses the concepts of construct and content validity, the requirements of convergent and discriminant evidence, norm and criterion-referenced interpretations, values in measurement and the uses of counterhypotheses, and the identification of bias. The importance of construct-referencing all measurement is noted. The need for a dialectical evaluation where a particular thesis is confronted with its antithetical elements is stressed. This approach should help uncover assumptions and ideologies implicit in many measurement and evaluation activities. (61 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The utility of external performance measurement tools in program evaluation

We describe the use of unfrozen tissue lenses in 42 cases of epikeratophakia in children aged 2-14 years. Fourteen operations were performed in an aphakic eye, 28 in combination with congenital or traumatic cataract extraction. The tissue lenses, made from unfrozen donor cornea according to an original design, healed in 91.5% of cases. The tissue lens was removed when epithelial growth was inadequate on its surface. A five-year follow-up showed that correction within 3.0 D of emmetropia was achieved in 73.7% of the eyes. Preoperatively, mean keratometry readings were 43.5+/-0.2 D, increasing postoperatively to 53.6+/-0.8 D. Mean spherical equivalent at the spectacle plane increased by 9.6+/-0.9 D. Our investigations show the efficacy and safety of non-freeze epikeratophakia in the correction of pediatric aphakia.     

Pressure measurement evaluation and accuracy validation: the Gabarith test

OBJECTIVE: The dynamic distortion introduced by manometric systems has been known for many years, with several methods developed to describe and quantify the degree of distortion. We developed the Gabarith as a technique to describe more accurately, and yet more simply, the dynamic accuracy of the chain of monitoring. SETTING: A pressure monitoring system transforms some input signal, i.e. the actual pressure waveform present in the artery, into some other shape of waveform, i.e. the waveform displayed on the patient monitor. This transformation is characterized by the transfer function of the total system. A complete technique to define the transfer function is to measure the response directly at many different frequencies and combine them to produce the dynamic response plot. METHOD: We described the dynamic response of a monitoring chain and we simplified the communication of this dynamic response to users by developing the Gabarith, as a tolerance envelope based on the frequency content of typical pressure waveforms. If a given monitoring chain's dynamic response (including a catheter, a pressure kit and a monitor) can be shown to fall within that tolerance envelope, the chain will provide adequate dynamic accuracy. CONCLUSION: "Gabarith tested" means that a pressure kit, in combination with a catheter and a monitor, has had its frequency response function measured and that the function falls within a tolerance band for dynamic accuracy. Passing a Gabarith means that a given level of accuracy will be reached when using the sets which have passed the corresponding test.     

Critical evaluation of measurement of platelet monoamine oxidase in man

Some biochemical characteristics such as substrate specificity, substrate affinity and inhibitor sensitivity of monoamine oxidase of human blood platelets were investigated. Tyramine, tryptamine and beta-phenylethylamine were used as substrates. The apparent Michaelis constants, maximal velocity rates and I50 for the inhibitor tranylcypromine were determined. The data were analyzed according to Lineweaver-Burk and Dixon. The influence of amitriptyline, a prototype of tricyclic antidepressants, on the selected variables (Km, V, I50), was studied. The parameters investigated showed remarkably low interindividual differences when healthy volunteers were tested. The inhibitor activity of amitriptyline towards platelet monoamine oxidase depends on the substrate used. Amitriptyline concentrations which showed a pronounced effect on the enzyme characteristics are significantly higher than plasma levels of the drug found under therapeutic conditions.     

测量不确定度与误差的区别及在评定中应注意的几个问题

本文介绍了测量不确定度与误差间的区别以及在评定中应注意的几个问题.文中结合当前国际上的一些动态就可忽略的不确定度来源、标准差的安全因子、A类评定和B类评定的应用、Up和U的选用、测量不确定度评定的简化建议等问题进行了讨论.     

A scheme for assessing measurement sensitivity in program evaluation and other applied research.

Presents a scheme for doing a preliminary measurement assessment study that permits an integrated examination of sensitivity to criterion-level effects, reliability and generalizability, and statistical power. Using a components-of-variance approach, the researcher can not only assess the adequacy of candidate measures but also explore the implications of various modifications to the planned measurement design. Application of the scheme is illustrated with data from 2 program evaluation studies: a study of juvenile delinquency prevention programs and a study on language development with about 700 children with language disorders. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health-related quality of life measurement for evaluation research and policy analysis.

Describes a unit of health status, the "Well-Year," which expresses the output of health programs in terms of the number of years and the health-related quality of life produced by a treatment or program. Dividing the cost of the program by the number of Well-Years that it produces gives the cost–utility of the program. This cost–utility ratio can be used in a general health policy model to compare the efficiency of different programs or to assess the relative contribution of different programs and providers in the health-care system. Different components of the model are useful (1) for the effectiveness of medical interventions, (2) to assess the quality of care, (3) to improve clinical decision making, (4) to assess needs of different populations, and (5) to understand causes of variations in health. A comprehensive standardized measure of health status has many advantages for health planning, decision analysis, and program evaluation. An example demonstrates how the relative production of Well-Years by psychologists might be compared to the contribution of other health-care services. (66 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multicenter evaluation of a patient-administered test for blood cholesterol measurement

BACKGROUND: In order to assess accuracy of a newly developed, noninstrumented, self-administered fingerstick test that measures cholesterol levels in whole blood, the AccuMeter Cholesterol Self-Test was evaluated for home-use by untrained consumers in a multicenter study. METHODS: A total of 486 untrained adult volunteers of varying age, occupation, and educational background were recruited at four sites. Participants received written instructions provided in the kit, access to a telephone "800" number for additional help, and, if necessary, a short instructional video available to consumers on request. Fingerstick cholesterol results obtained by untrained volunteers were compared with paired venous serum results obtained by the Abell-Kendall cholesterol reference method. After application of exclusion criteria, 79.0% (384/486) of subjects had AccuMeter fingerstick results available for comparison with the reference method. RESULTS: Results obtained with the AccuMeter test correlated well with the Abell-Kendall results (r = 0.91). There was a mean overall bias for the AccuMeter of -0.116 +/- 0.528 mmol/liter (-2.2%), with a mean absolute bias of 0.398 +/- 0.367 mmol/liter (7.6%). Biases at the National Cholesterol Education Program cutpoints of 5.20 and 6.20 mmol/liter were -2.2 and -2.5%, respectively. Subjects with high-risk total cholesterol values (> or = 6.20 mmol/liter) were correctly classified 80.0% of the time, with an additional 18.8% placed in the borderline category (5.20-6.20 mmol/liter); 1.2% were inappropriately placed in the desirable category. No subjects were placed in the high-risk category by the AccuMeter test if they had a desirable cholesterol value by the reference method, while 9.8% were placed in this category if they were in fact borderline. CONCLUSIONS: This test appears to be a useful addition to available options in the effort to increase awareness of cholesterol as a heart disease risk factor. A large portion of untrained consumers were able to perform the AccuMeter Cholesterol Self-Test and obtain comparable results to the reference method. This test for the first time allows consumers to determine their own cholesterol values, with a reasonably good degree of accuracy.