9762 papers found
The metrological system is presented in its structure as a network, and as such analyzed in view of its efficiency. It is shown that the general strategies adopted at this regards in the small-world networks can be usefully exploited in this case, and some empirical solutions are derived.
This discussion paper presents issues in the design of ad-hoc, networked measurement systems. Key requisites are summarized at first. Then, architectural features will be analyzed in order to let a designer be aware of advantages and efforts of presented choices.
This paper describes methods and presents verification results of improvement of algorithms for visualization of sound fields based on near-field acoustical holography (NAH) by the double layer holografic array (DLA) measurement and iterative technique to remove disturbing sound fields which are not in the examinated area under measurement planes (holograms).
We present in this paper a novel method for comparing alternative 2D measurements. The method is based on a new image registration algorithm developed for the automatic registration and alignment of randomly textured image data. Our aim in the algorithm development has been to enable fast registration of the measured 2D property maps without the need for special registration marks. To improve robustness, the maps are registered in two steps; the first step exhibits plain translation and the second phase iteratively refines the transformation estimate. Sub-pixel registration accuracy is...
The main purpose of this paper is to present application of hybrid (i.e. combined physical and in silico) modeling and nonlinear (fractal) biosignal analysis for improving quality of life through modeling and knowledgebased measurements in medicine.
A gamma ray tomographic reconstruction of catalyst concentration distribution in laboratory experiments is presented. The images are generated by gamma transition measurements in an experimental riser simulating flow experiments. The manual scanner is adequate for mapping radial catalyst concentration distribution under spatial resolution of 0.002 m and density resolution of 10 kg/m³.
An efficiency curve obtained in a gamma-ray spectrometric system using a high purity germanium detector and radioactive standards of 133 Ba, 152 Eu and 166m Ho in an energy range of 50 to 1400 keV was established for metrological purposes. To do this, the efficiency response of the detector was used considering 29 different energies. This allowed calibrating various gammaemitter radioactive point sources, within of a 50 kBq to 550 MBq activity range, with expanded uncertainties below 2.5% at two-sigma confidence level ( k =2). The obtained activity value for 22 Na was validated by sum-peak...
The determination of the uncertainty of measurement results is one of the most demanding but unpopular tasks in metrology. One of several reasons for this fact is the lack of well-structured models of non-ideal measurement processes on one hand and of qualification processes, which determine measurement uncertainties, on the other hand. Easily available and universally valid models would greatly help to improve measurement quality. But since process modelling is very laborious, practitioners are additionally confronted with cost-benefit questions. This paper starts with the most popular but...
Outside of the classical physical and chemical metrologies, there is a large field of measurement, which is called dimensionless or “soft “ metrology by analogy with hard and soft sciences. The objective of this presentation is to provide an overview of this field, to analyze the methods used and their linkage to classical metrology. The author will take 3 examples, an historical one, the measurement of human character, and two modern research fields, software usability and customer satisfaction. He will also show the recent efforts from the European Commission, as part of the New Emerging...
The aim of this study is to fit a calibration curve to a multivariate system. The experimental data are generated from the calibration of the aerodynamic external balance of the subsonic wind n.º 2, the TA-2, of the Brazilian Aerospace Institute, IAE. Multilayer Perceptrons (MLPs) Artificial Neural Networks are employed. To fit the calibration curve, the MLPs are submitted to the learning process. The measurement uncertainties are taken into consideration, through the modification of the MLP learning algorithm, which in its classical approach, considers the data points free from error...