Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "accuracy analysis" wg kryterium: Wszystkie pola


Wyświetlanie 1-8 z 8
Tytuł:
Comparative accuracy analysis of triangulated surface models of a fossil skull digitized with various optic devices
Autorzy:
Garashchenko, Yaroslav
Kogan, Ilja
Rucki, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/2052109.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Madygenerpeton
optical measurement
triangulated model
polygonal analysis
accuracy
Opis:
Digital metrology was applied for evaluate 3D models of the unique skull of a fossil tetrapod, Madygenerpeton pustulatum, generated using various 3D digitization methods. The skull surface is covered by minute tubercles making it challenging for digitization with appropriate accuracy. Uniqueness and fragility of the specimen preclude the use of tactile measuring systems for creating a standardized reference model. To overcome this problem, comparative analysis of the triangulated models generated from the clouds of points obtained with seven different devices was conducted using the Geomagic Studio and Autodesk PowerShape CAD software. In the proposed approach, geometrically and dimensionally closest-fitting models underwent detailed statistical analysis between surface polygons in three steps. First, 3D models obtained from different scanning methods were compared with each other in couples. Next, statistical analysis of the differences between the coupled models was performed. Finally, a rating list of the models related to the required accuracy was prepared. The proposed approach is applicable to any other scanned object, especially in palaeontological applications, where each object is unique and exhibits individual features.
Źródło:
Metrology and Measurement Systems; 2022, 29, 1; 37-51
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Analysis Of Accuracy Of Selected Methods Of Measuring The Thermal Resistance Of IGBTs
Autorzy:
Górecki, K.
Górecki, P.
Powiązania:
https://bibliotekanauki.pl/articles/220969.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
IGBT
thermal resistance
measurements
transistor
semiconductor devices
Opis:
In the paper selected methods of measuring the thermal resistance of an IGBT (Insulated Gate Bipolar Transistor) are presented and the accuracy of these methods is analysed. The analysis of the measurement error is performed and operating conditions of the considered device, at which each measurement method assures the least measuring error, are pointed out. Theoretical considerations are illustrated with some results of measurements and calculations.
Źródło:
Metrology and Measurement Systems; 2015, 22, 3; 455-464
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the accuracy of the NDIR-based CO2 sensor for breath analysis
Autorzy:
Prokopiuk, Artur
Bielecki, Zbigniew
Wojtas, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/2052156.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
NDIR
CO2 sensors
breath analysis
absorption spectroscopy
Opis:
The paper presents an analysis and practical study of the temperature and pressure influence on a non-dispersive infrared (NDIR) sensor for measuring the concentration of carbon dioxide in human breath. This sensor is used for monitoring patients’ carbon dioxide (CO2) in the exhaled air. High precision and accuracy of CO2 concentration measurements are essential in air sampling systems for breath analysers. They, however, require an analysis of the influence of the human exhaled air pressure and temperature on the NDIR CO2 sensor. Therefore, analyses of the changes in concentration were carried out at a pressure from 986 mbar to 1027 mbar and a temperature from 20°C to 36°C. Finally, corresponding correction coefficients were determined which allow to reduce the relative uncertainty of CO2 sensor measurements results from 19% to below 5%.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 803-812
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the impact of interior orientation parameters in different UAV-based image-block compositions on positional accuracy
Autorzy:
Grigillo, D.
Uršič, M.
Bone, M.
Ambrožič, T.
Pavlovčič-Prešeren, P.
Kosmatin-Fras, M.
Powiązania:
https://bibliotekanauki.pl/articles/220711.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unmanned aerial vehicle
calibration field
interior orientation parameters
positional accuracy assessment
Opis:
Understanding the factors that influence the quality of unmanned aerial vehicle (UAV)-based products is a scientifically ongoing and relevant topic. Our research focused on the impact of the interior orientation parameters (IOPs) on the positional accuracy of points in a calibration field, identified and measured in an orthophoto and a point cloud. We established a calibration field consisting of 20 materialized points and 10 detailed points measured with high accuracy. Surveying missions with a fixed-wing UAV were carried out in three series. Several image blocks that differed in flight direction (along, across), flight altitude (70 m, 120 m), and IOPs (known or unknown values in the image-block adjustment) were composed. The analysis of the various scenarios indicated that fixed IOPs, computed from a good geometric composition, can especially improve vertical accuracy in comparison with self-calibration; an image block composed from two perpendicular flight directions can yield better results than an image block composed from a single flight direction.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 617-629
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An assessment of applicability of the two-dimensional wavelet transform to assess the minimum chip thickness determination accuracy
Autorzy:
Gogolewski, Damian
Makieła, Włodzimierz
Nowakowski, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/1849153.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelet analysis
face milling
minimum chip thickness
surface texture
Opis:
The objective of the study was to assess the potential use of optical measuring instruments to determine the minimum chip thickness in face milling. Images of scanned surfaces were analyzed using mother wavelets. Filtration of optical signals helped identify the characteristic zones observed on the workpiece surface at the beginning of the cutting process. The measurement data were analyzed statistically. The results were then used to estimate how accurate each measuring system was to determine the minimum uncut chip thickness. Also, experimental verification was carried out for each mother wavelet to assess their suitability for analyzing surface images.
Źródło:
Metrology and Measurement Systems; 2020, 27, 4; 659-672
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the temperature field using liquid crystal thermography and analysis of two-phase flow structures in research on boiling heat transfer in a minichannel
Autorzy:
Piasecka, M.
Powiązania:
https://bibliotekanauki.pl/articles/220691.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
temperature measurement
liquid crystal thermography
measurement accuracy
void fraction
Opis:
The paper presents the application of liquid crystal thermography for temperature determination and visualisation of two phase flow images on the studied surface. Properties and applications of thermochromic liquid crystals are discussed. Liquid crystals were applied for two-dimensional detection of the temperature of the heating foil forming one of the surfaces of the minichannel along which the cooling liquid flowed. The heat flux supplied to the heating surface was altered in the investigation and it was accompanied by a change in the color distribution on the surface. The accuracy of temperature measurements on the surface with liquid crystal thermography is estimated. The method of visualisation of two-phase flow structures is described. The analysis of monochrome images of flow structures was employed to calculate the void fraction for some cross-sections. The flow structure photos were processed using Corel graphics software and binarized. The analysis of phase volumes employed Techsystem Globe software. The measurement error of void fraction is estimated.
Źródło:
Metrology and Measurement Systems; 2013, 20, 2; 205-216
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of sine-wave frequency estimation methods in respect of speed and accuracy for a few observed cycles distorted by noise and harmonics
Autorzy:
Borkowski, J.
Kania, D.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/220583.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DFT spectrum interpolation
short-time frequency estimation
statistical analysis
Prony LS
TLS
ESPRIT
Opis:
The paper deals with frequency estimation methods of sine-wave signals for a few signal cycles and consists of two parts. The first part contains a short overview where analytical error formulae for a signal distorted by noise and harmonics are presented. These formulae are compared with other accurate equations presented previously by the authors which are even more accurate below one cycle in the measurement window. The second part contains a comparison of eight estimation methods (ESPRIT, TLS, Prony LS, a newly developed IpDFT method and four other 3-point IpDFT methods) in respect of calculation time and accuracy for an ideal sine-wave signal, signal distorted by AWGN noise and a signal distorted by harmonics. The number of signal cycles is limited from 0.1 to 3 or 5. The results enable to select the most accurate/fastest estimation method in various measurement conditions. Parametric methods are more accurate but also much slower than IpDFT methods (up to 3000 times for the number of samples equal to 5000). The presented method is more accurate than other IpDFT methods and much faster than parametric methods, which makes it possible to use it as an alternative, especially in real-time applications.
Źródło:
Metrology and Measurement Systems; 2018, 25, 2; 283-302
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction of small components using photogrammetry: a quantitative analysis of the depth of field influence using a miniature step gauge
Autorzy:
Guerra, Maria Grazia
Galantucci, Luigi Maria
Lavecchia, Fulvio
De Chiffre, Leonardo
Powiązania:
https://bibliotekanauki.pl/articles/1849141.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metrology of small parts
uncertainty
photogrammetry
depth of field
miniature step gauge
flatness
dimensional accuracy
Opis:
In this work, authors investigated the effect of the Depth of Field (DoF) reduction, arising when the acquisition of small objects is carried out with a photogrammetry-based system using a Digital Single Lens Reflex (DSLR) camera and the structure from motion (SfM) algorithm. This kind of measuring instrument is very promising for industrial metrology according to the paradigms of the fourth industrial revolution. However, when increasing the magnification level, necessary for the reconstruction of sub-millimetric features, there is a corresponding decrease of the DoF, leading to possible effects on the reconstruction accuracy. Thus, the effect of the DoF reduction was analysed through the reconstruction of a well-known artefact: the step gauge. The analysis was conducted considering the theory behind the DoF concept, the analysis of the 2D images, input of photogrammetric reconstruction and, finally, the results in terms of dimensional verification of the reconstructed step gauge.
Źródło:
Metrology and Measurement Systems; 2021, 28, 2; 323-342
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies