المؤلفون: Herweg, Jonathan, Schaller, Michael, Böck, Andreas Charles, Herz, Kevin, Künkler, André, Wiedenmann, Ernst, Wolf, Michael, Klauenberg, Katy, Müller-Schöll, Christian, Sander, Christian

المساهمون: Physikalisch-Technische Bundesanstalt (PTB)

الوصف: Der vorliegende Leitfaden soll den Unterschied zwischen Prüfwertunsicherheit und Messunsicherheit nach den GUM (Guide to the expression of uncertainty in measurements) Dokumenten herausstellen und die Folgen dieses Unterschieds für die Anwendung bei der Bestimmung der Konformität mit Spezifikationen verdeutlichen. Die grundlegenden Aussagen sind ausdrücklich nicht beschränkt auf einzelne Messgrößen oder die Anwendung im Rahmen von Akkreditierungen.

وصف الملف: application/pdf

الإتاحة: https://doi.org/10.7795/550.20240412Test

المؤلفون: Bernburg, Hugalf, Elster, Clemens, Klauenberg, Katy

المصدر: Applied Stochastic Models in Business and Industry ; ISSN 1524-1904 1526-4025

الوصف: The aim is to demonstrate the reliability of a population at consecutive points in time, where a sample at each current point must prove that at least 100% of the devices function until the next point with a probability of at least . To test the reliability of the population, we flexibilise standard lifetime models by allowing the unknown parameter(s) of the corresponding counting process to vary in time. At the same time, we assign a prior distribution that assumes the parameters to be constant within a certain interval. This flexibilisation has several advantages: it can be applied for all parametric lifetimes; its Markov property allows the efficient derivation of the number of defective devices, even for a large number of testing times; and the inference is less certain and hence more realistic and leads to less frequent acceptance of poor quality populations. On the other hand, the inference is stabilised by the informative prior. Based on the flexibilisation of the homogeneous Poisson process (HPP), we derive acceptance sampling plans to test the future reliability of a population. Applying the zero failure sampling plans on simulations of Weibull processes shows their good frequentist properties and their robustness. In the case of utility meters subject to German regulations (Mess‐ und Eichverordnung (MessEV). 2014: 2010–2073.), application of the derived sequential sampling plans when the conditions of these plans are met can lead to an extension of the verification validity period. These sampling plans protect the consumer better than those from an HPP and are still cost efficient.

الإتاحة: https://doi.org/10.1002/asmb.2863Test

المؤلفون: Klauenberg, Katy, Müller, Cord A., Elster, Clemens

المصدر: Statistics and Public Policy, 2021, Vol. 8, No. 1, 9-17

مصطلحات موضوعية: Statistics - Applications

الوصف: Millions of measuring instruments are verified each year before being placed on the markets worldwide. In the EU, such initial conformity assessments are regulated by the Measuring Instruments Directive (MID). The MID modules F and F1 on product verification allow for statistical acceptance sampling, whereby only random subsets of instruments need to be inspected. This paper re-interprets the acceptance sampling conditions formulated by the MID. The new interpretation is contrasted with the one advanced in WELMEC guide 8.10, and three advantages have become apparent. Firstly, an economic advantage of the new interpretation is a producers' risk bounded from above, such that measuring instruments with sufficient quality are accepted with a guaranteed probability of no less than 95 %. Secondly, a conceptual advantage is that the new MID interpretation fits into the well-known, formal framework of statistical hypothesis testing. Thirdly, the new interpretation applies unambiguously to finite-sized lots, even very small ones. We conclude that the new interpretation is to be preferred and suggest re-formulating the statistical sampling conditions in the MID. Re-interpreting the MID conditions implies that currently available sampling plans are either not admissible or not optimal. We derive a new acceptance sampling scheme and recommend its application.
Comment: accepted, Statistics and Public Policy

الوصول الحر: http://arxiv.org/abs/2103.07431Test

المؤلفون: Klauenberg, Katy, Greenwood, John, Foyer, Gisa

المصدر: Metrologia ; volume 60, issue 5, page 054004 ; ISSN 0026-1394 1681-7575

الوصف: According to ISO/IEC 17025:2017 statements of conformity must identify the decision rule applied, they must be risk-based and account for uncertainty. In legal metrology and often among testing and calibration laboratories, there is the need to reuse measurement-based conformity statements to disseminate acceptability of measurement results. In particular, decision rules are required that allow the statement of conformity for a linear combination of quantities for which, in turn, conformity statements are available. These decision rules should be simple and use information that is typically available, and they should comply with ISO/IEC 17025:2017, again by accounting for the level of risk and for uncertainty following the suite of documents of the GUM (the Guide to the Expression of Uncertainty in Measurement). Existing guidance requires the input and evaluation of standard uncertainties, or even of distributions, to derive statements of conformity, and as such may be inapplicable, or the required effort may deter practitioners. After reviewing the existing guidance, this research will identify typical settings which lead to particularly simple decision rules for stating conformity for linear combinations of quantities. These new decision rules are based on the specification limits and on information implicitly available in the decision rules of each input quantity. The rules will be proven, they are generalizable, intended to comply with ISO/IEC 17025:2017 and the GUM documents, and suitable to easily state the risk of not conforming to the weighted sum of the input specifications. For practitioners, a quick reference on feasible conformity statements for linear combinations of quantities is provided. The applicability of and need for the new decision rules are illustrated by two examples involving the legally regulated weighing of long vehicles and of net loads.

الإتاحة: https://doi.org/10.1088/1681-7575/acf3ebTest

المؤلفون: Klauenberg, Katy, Martens, Steffen, Bošnjaković, Alen, Cox, Maurice G., van der Veen, Adriaan M.H., Elster, Clemens

المساهمون: European Metrology Programme for Innovation and Research, Horizon 2020, Horizon 2020 Framework Programme

المصدر: Measurement ; volume 187, page 110340 ; ISSN 0263-2241

الإتاحة: https://doi.org/10.1016/j.measurement.2021.110340Test
https://api.elsevier.com/content/article/PII:S0263224121012355?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S0263224121012355?httpAccept=text/plainTest

المؤلفون: Klauenberg Katy, Wübbeler Gerd, Elster Clemens

المصدر: Measurement Science Review, Vol 19, Iss 5, Pp 204-208 (2019)

مصطلحات موضوعية: systematic effect, correction, uncorrected estimate, gum, standard uncertainty, consistency, transferability, Mathematics, QA1-939

الوصف: In practice, measurement results are sometimes described by an estimate, which is not the best one as defined in the GUM. Such alternative estimates arise when the result of a measurement is not corrected for all systematic effects. No recommendation exists in the GUM for associating an uncertainty with an uncorrected estimate.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1335-8871Test

الوصول الحر: https://doaj.org/article/26e7a7171aca4b54a9092e08686a7c24Test

المؤلفون: Klauenberg, Katy, Walzel, Monika, Ebert, Bernd, Elster, Clemens

مصطلحات موضوعية: Articles

الوصف: Immunoassays are capable of measuring very small concentrations of substances in solutions and have an immense range of application. Enzyme-linked immunosorbent assay (ELISA) tests in particular can detect the presence of an infection, of drugs, or hormones (as in the home pregnancy test). Inference of an unknown concentration via ELISA usually involves a non-linear heteroscedastic regression and subsequent prediction, which can be carried out in a Bayesian framework. For such a Bayesian inference, we are developing informative prior distributions based on extensive historical ELISA tests as well as theoretical considerations. One consideration regards the quality of the immunoassay leading to two practical requirements for the applicability of the priors. Simulations show that the additional prior information can lead to inferences which are robust to reasonable perturbations of the model and changes in the design of the data. On real data, the applicability is demonstrated across different laboratories, for different analytes and laboratory equipment as well as for previous and current ELISAs with sigmoid regression function. Consistency checks on real data (similar to cross-validation) underpin the adequacy of the suggested priors. Altogether, the new priors may improve concentration estimation for ELISAs that fulfill certain design conditions, by extending the range of the analyses, decreasing the uncertainty, or giving more robust estimates. Future use of these priors is straightforward because explicit, closed-form expressions are provided. This work encourages development and application of informative, yet general, prior distributions for other types of immunoassays.

وصف الملف: text/html

العلاقة: http://biostatistics.oxfordjournals.org/cgi/content/short/16/3/454Test; http://dx.doi.org/10.1093/biostatistics/kxu057Test

الإتاحة: https://doi.org/10.1093/biostatistics/kxu057Test
http://biostatistics.oxfordjournals.org/cgi/content/short/16/3/454Test

المؤلفون: Klauenberg, Katy

الوصول الحر: https://www.europeana.eu/item/2048441/item_BIP7H5WXOMJ4N2JK44VQNKXK62KOPIU2?utm_source=api&utm_medium=api&utm_campaign=YuvuWBeCaTest

المؤلفون: Klauenberg, Katy.

المصدر: kostenfrei.

الوصف: Freiburg (Breisgau), University, Diss., 2007.

الإتاحة: http://deposit.d-nb.de/cgi-bin/dokserv?idn=985333901Test
http://www.freidok.uni-freiburg.de/volltexte/3014/pdf/KlauenbergThesis.pdfTest
http://www.freidok.uni-freiburg.de/volltexte/3014Test/

المؤلفون: Van Der Veen, Adriaan M. H., Cox, Maurice, Greenwood, John, Karahodžic, Vedran, Martens, Steffen, Klauenberg, Katy, Elster, Clemens, Fischer, Nicolas, Sousa, João, Martins, Luis, A.S. Ribeiro, D. Loureiro, M.C. Almeida, M.A. Silva, R. Brito, A.C. Soares, Shirono, Katsuhiro

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::4c9439e916a8e08d238fb435d971d289Test