The Guide to the Expression of Uncertainty in Measurement (GUM) is de facto standard for evaluation measurement uncertainty metrology. Recently, has been proposed on basis probability density functions (PDFs) using a Monte Carlo method. relation between this PDF approach and method described GUM outlined. required numerical calculation illustrated by its application two examples. results obtained examples are compared corresponding when applying GUM.

Abstract Purpose To propose and illustrate a safety concept for multichannel transmit coils in MRI based on finite‐differences time‐domain (FDTD) simulations validated by measurements. Materials Methods FDTD of specific absorption rate (SAR) distributions cylindrical agarose phantom were carried out various radio frequency (RF) driving conditions four‐element coil array. Additionally, maps amplitude, signal phase, temperature rise following RF heating measured MRI. Results Quantitative...

Abstract The applications of virtual metrology and the concept using experiments (VEs) or digital twins in measurement tasks have gained significant interest recent years. When real measurements are costly scarce, a VE can replicate complex mathematical physical models. As representation process, can, among other use-cases, be used an uncertainty evaluation. Here, simulated observations combined without explicit knowledge model for measurand – usual requirement evaluation according to GUM...

We apply a recently developed multivariate statistical data analysis technique-so called blind source separation (BSS) by independent component analysis-to process magnetoencephalogram recordings of near-DC fields. The extraction fields from MEG has great relevance for medical applications since slowly varying DC-phenomena have been found, e.g., in cerebral anoxia and spreading depression animals. Comparing several BSS approaches, it turns out that an algorithm based on temporal...

Bandpass correction in spectrometer measurements using monochromators is often necessary order to obtain accurate measurement results. The classical approach of bandpass based on local polynomial approximations and the use finite differences. Here we compare this with an extension Richardson–Lucy method, which well known image processing, but has not been applied spectrum yet. Using extensive simulation study a practical example, demonstrate potential method. In contrast approach, it robust...

A method for the simultaneous correction of bandpass and stray-light effects in array spectroradiometer data is presented. The based on inversion instrument matrix a device determined with help tuneable lasers. By applying Tikhonov regularization technique, straightforward measurement results possible.

Adaptive Monte Carlo schemes can be used to determine the number of trials (the evaluations measurement model) necessary for evaluation uncertainty according Supplement 1 GUM (GUM S1). The goal is reach a prescribed numerical accuracy results estimate, associated standard and coverage interval endpoints) chosen confidence level. It shown that simple sequential adaptive may not perform well in this regard an alternative method based on two-stage procedure due Stein proposed. implementation...

Infrared scattering scanning near-field optical microscopy (IR s-SNOM) provides for spectroscopic imaging with nanometer spatial resolution, yet full spatio-spectral is constrained by long measurement times.Here, we demonstrate the application of compressed sensing algorithms to achieve hyperspectral FTIR-based nano-imaging at an order magnitude faster speed same spectral content compared conventional approaches.At example spectroscopy a single vibrational resonance, discuss relationship...

A virtual experiment simulates a real measurement process by means of numerical model. The model produces data whose properties reflect those the observed in experiment. In this work, we explore how results can be employed context uncertainty evaluation for corresponding was based on Guide to Expression Uncertainty Measurement (GUM), which defines de facto standard metrology. We show that, under specific assumptions about structure and variance data, experiments combination with Monte Carlo...

To reduce physiological artifacts in magnetoencephalographic (MEG) and electroencephalographic recordings, a number of methods have been applied the past such as principal component analysis, signal-space projection, regression using secondary information, independent analysis. This method has become popular it does not constraints orthogonality between artifact signal or need for priori information. Applying time-delayed decorrelation algorithm to raw data from visual stimulation MEG...

Abstract The paper gives a short overview of various methods optical mammography, emphasizing scanning time-domain mammography. results clinical study on mammography are reviewed, comprising 154 patients carrying total 102 carcinomas validated by histology. A visibility score attributed to each carcinoma as qualitative measure tumour detectability indicates acceptable sensitivity but poor specificity for discrimination between malignant and benign lesions. Likewise, multi-variate statistical...

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...

Virtual experiments are a digital representation of real measurement and play crucial role in modern sciences metrology. Beyond their common usage as modeling validation tool, virtual experiment may also be employed to perform parameter sensitivity analysis or carry out uncertainty evaluation. For the latter compliant with statistical principles metrological guidelines, procedure obtain an estimate corresponding requires careful consideration. We employ Monte Carlo sampling using that allows...

Most functional brain imaging methods detect neuronal activations indirectly through the accompanying neurovascular response. Here, we demonstrate that a novel methodological approach, combination of DC-magnetoencephalography (DC-MEG) and near-infrared spectroscopy (NIRS), allows non-invasive assessment dynamics coupling in human brain: detecting directly slow processes (with time constants 30s), DC-MEG revealed, even unaveraged recordings, sustained at pericentral hand cortices...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A novel approach for the determination of complex residual error parameters a calibrated one-port vector network analyzer (VNA) is proposed. The method based on single-reflection measurement employing high-precision airline terminated by short. complex-valued directivity and source match are extracted over entire measured frequency range applying sophisticated data analysis scheme utilizing...

Regression is an important task in metrology and least-squares methods are often applied this context. Bayesian inference provides alternative that can take into account available prior knowledge. We illustrate similarities differences of the two approaches terms a particular nonlinear regression problem. The impact knowledge utilized depends on amount information contained data, by considering data sets with different signal-to-noise ratios relevance employed for results investigated. In...

Recently, results for the CO(2) R(12) line strength parameter have been reported, which differ significantly and are inconsistent with respect to quoted uncertainties. We investigate what extent this inconsistency might be caused by chosen data analysis methods. To end, we assess compare a parametric fitting procedure non-parametric approach. apply methods simulated measured spectra, specify conditions required safe application of two procedures. For our present data, corresponding satisfied...

Neuroimaging techniques, such as fMRI, PET and near-infrared spectroscopy, monitor task-related neuronal activations in the brain indirectly through associated neurovascular/metabolic responses. To assess primary directly, magnetoencephalography was combined here with a mechanical modulation of head-to-sensor position signal separation via independent component analysis. In all five subjects this approach allowed to time evolution DC fields (< 0.1 Hz) over left hemisphere related complex...

A key requirement for the evaluation of measurement uncertainty in metrology is its transferability. This particularly relevant ensuring traceability through a chain measurements. The GUM [JCGM 100] requires that ' it should be possible to use directly evaluated one result as component evaluating another which first used'. implements transfer by applying variance propagation linear models or can well approximated linearization. GUM-S1 101] has been released broaden scope cover also...

The Guide to the Expression of Uncertainty in Measurement (GUM) has led a harmonization uncertainty evaluation throughout metrology. simplicity its employed methodology fostered broad acceptance GUM among metrologists. However, this also compromises best practice and does not provide state-of-the-art data analysis. Specifically, metrologists often possess useful prior knowledge about measurand which cannot be accounted for by GUM. Bayesian evaluation, on other hand, takes as starting point....

Near-field goniometric measurements are employed to determine the photometric characteristics of light sources, i.e., spatial and angular distribution emitted light. To this end, a complex measurement system consisting goniometer CCD-based imaging photometer is employed. In order gain insight into enable characterization whole setup, we propose apply computer model conduct virtual experiments. Within model, current state all parts experiment can be easily controlled. The reliability...