A5069688881- Scientific Measurement and Uncertainty Evaluation
- Advanced Statistical Process Monitoring
- Advanced Statistical Methods and Models
- Optical Imaging and Spectroscopy Techniques
- Geology and Paleoclimatology Research
- Engineering Applied Research
- Cryospheric studies and observations
- Advanced Measurement and Metrology Techniques
- Climate change and permafrost
- Statistical Methods and Bayesian Inference
- Statistical and numerical algorithms
- Structural Health Monitoring Techniques
- Radioactive Decay and Measurement Techniques
- Hemodynamic Monitoring and Therapy
- Statistical Distribution Estimation and Applications
- Photoacoustic and Ultrasonic Imaging
- Image and Signal Denoising Methods
- Statistical Methods in Clinical Trials
- Advanced Sensor Technologies Research
- Probabilistic and Robust Engineering Design
- Electrostatic Discharge in Electronics
- Image Retrieval and Classification Techniques
- Water Quality Monitoring and Analysis
- Infrared Thermography in Medicine
- Sensor Technology and Measurement Systems
Physikalisch-Technische Bundesanstalt
2013-2024
Polish Botanical Society
2020
University of Sheffield
2007-2011
A multi-center study has been set up to accurately characterize the optical properties of diffusive liquid phantoms based on Intralipid and India ink at near-infrared (NIR) wavelengths.Nine research laboratories from six countries adopting different measurement techniques, instrumental set-ups, data analysis methods determined their best relative uncertainties dilutions prepared with common samples two compounds.By exploiting a suitable statistical model, comprehensive reference values three...
When the Guide to Expression of Uncertainty in Measurement (GUM) and methods from its supplements are not applicable, Bayesian approach may be a valid welcome alternative. Evaluating posterior distribution, estimates or uncertainties involved inferences often requires numerical avoid high-dimensional integrations. Markov chain Monte Carlo (MCMC) sampling is such method—powerful, flexible widely applied. Here, concise introduction given, illustrated by simple, typical example metrology.
Following the Guide to expression of uncertainty in measurement (GUM), slope and intercept straight-line regression tasks can be estimated their evaluated by defining a model. Minimizing weighted total least-squares functional appropriately defines such model when both input quantities (X Y) are uncertain. This paper compares straight line propagating distributions law propagation (LPU). The latter is turn often approximated because non-linear does not have closed form. We reason that...
Regression is a common task in metrology and often applied to calibrate instruments, evaluate inter-laboratory comparisons or determine fundamental constants, for example. Yet, regression model cannot be uniquely formulated as measurement function, consequently the Guide Expression of Uncertainty Measurement (GUM) its supplements are not applicable directly. Bayesian inference, however, well suited tasks, has advantage accounting additional priori information, which typically robustifies...
The European Metrology Research Programme (EMRP) is currently funding project EMRP-NEW04 on novel mathematical and statistical approaches to uncertainty evaluation. One focus of the evaluation in context regression parametric inverse problems. development methods for such problems will be carried out close connection with four application examples. Here we outline these examples, present some first results.
Abstract In practice, measurement results are sometimes described by an estimate, which is not the best one as defined in GUM . Such alternative estimates arise when result of a corrected for all systematic effects. No recommendation exists associating uncertainty with uncorrected estimate. A common choice guidelines and literature <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mrow> <m:mi>u</m:mi> <m:mo>(</m:mo> <m:msup> <m:mi>y</m:mi> <m:mo>′</m:mo> </m:msup>...
Immunoassays are capable of measuring very small concentrations substances in solutions and have an immense range application. Enzyme-linked immunosorbent assay (ELISA) tests particular can detect the presence infection, drugs, or hormones (as home pregnancy test). Inference unknown concentration via ELISA usually involves a non-linear heteroscedastic regression subsequent prediction, which be carried out Bayesian framework. For such inference, we developing informative prior distributions...
Intrinsic reduced scattering coefficient of Intralipid and intrinsic absorption Indian ink at NIR wavelengths are accurately assessed in a multi-center study involving different techniques, instrumental set-ups, analysis methods.
Background: Immunoassays are biochemical tests applied to measure even very small amounts of substance using the highly specific binding between an antibody and its antigen. They have a wide range applications. The measurement however, might be associated with substantial uncertainty; this can significant consequences for any diagnosis, or clinical decision. An international comparability study was thus performed assess sources uncertainty involved in estimation protein cytokine...
Ensuring measurement trueness, compliance with regulations and conformity standards are key tasks in metrology which often considered at the time of an inspection. Current practice does not always verify quality after or between inspections, calibrations, laboratory comparisons, assessments, etc. Statistical models describing behavior over may ensure reliability, i.e. they give probability functioning, survival until some future point time.
The multivariate Gaussian model is frequently applied in metrology and many other fields. Notably, the recent Supplement 2 to GUM (an extension of S1 problems) makes extensive use normal distributions. Frequently, mean covariance this distribution have be estimated from observations. If no additional knowledge available these situations, a non-informative prior has specified for Bayesian estimation.Since paradigms exist according which can chosen, we will identify influence that selected...
Abstract In metrology, the normal distribution is often taken for granted, e. g. when evaluating result of a measurement and its uncertainty, or establishing equivalence measurements in key supplementary comparisons. The correctness this inference subsequent conclusions dependent on normality assumption, such that validation assumption essential. Hypothesis testing formal statistical framework to do so, introduction will describe how tests detect violations distributional assumption....
Abstract The inspection of measurement devices according to statistical sampling plans allows conclusions be drawn about the reliability a whole population devices. However, confirming high levels requires large sample sizes and is thus expensive or even infeasible. For example, 99.5% can only guaranteed with 90% confidence by inspecting each item in 280 (see ISO 2859‐2). When judged not exceeding certain threshold, this research provides convenient solution allowing considerably more...
Abstract The aim is to demonstrate the reliability of a population at consecutive points in time, where sample each current point must prove that least 100% devices function until next with probability . To test population, we flexibilise standard lifetime models by allowing unknown parameter(s) corresponding counting process vary time. At same assign prior distribution assumes parameters be constant within certain interval. This flexibilisation has several advantages: it can applied for all...
Measurement uncertainty is key to assessing, stating and improving the reliability of measurements. An understanding measurement basis for confidence in measurements required by many communities; among others national metrology institutes, accreditation bodies, calibration testing laboratories, as well legal metrology, at universities different fields. important cornerstone convey an provide training. This article identifies status needs training on each above communities those teaching...
Millions of measuring instruments are verified each year before being placed on the markets worldwide. In EU, such initial conformity assessments regulated by Measuring Instruments Directive (MID). The MID modules F and F1 product verification allow for statistical acceptance sampling, whereby only random subsets need to be inspected. This article re-interprets sampling conditions formulated MID. new interpretation is contrasted with one advanced in WELMEC guide 8.10, three advantages have...
The CCQM study P58.1 assessed the equivalence of immunoassay measurements between participating NMIs. aim was to demonstrate determine mass concentration clinically-relevant protein human cardiac troponin I (cTnI) present at low relative sample matrix. measurement using traceability a common certified reference material. To quantify cTnI, participants used homogeneous sandwich-based with an enzymatic amplification step. antibody format consisted single capture and detection (referred as 1 +...
Abstract According to ISO/IEC 17025:2017 statements of conformity must identify the decision rule applied, they be risk-based and account for uncertainty. In legal metrology often among testing calibration laboratories, there is need reuse measurement-based disseminate acceptability measurement results. particular, rules are required that allow statement a linear combination quantities which, in turn, available. These should simple use information typically available, comply with 17025:2017,...