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Wyszukujesz frazę "geometric measurement" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
A study on loops and eddies identified from the trajectories of drifters in the North Indian Ocean
Autorzy:
Dora, S.
Aparna, S.G.
Powiązania:
https://bibliotekanauki.pl/articles/2078762.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
trajectory
loop testing
eddy
geometric measurement
Indian Ocean
Opis:
We identify loops and eddies from the trajectories of the drifters in the North Indian Ocean (NIO) from October 1985 to March 2019. We use the geometric identification method to identify loops and eddies and compare them with the loops identified from loopers provided by Lumpkin (2016). In NIO, the number of loops estimated from loopers is less than the number of loops and eddies identified by the geometric identification method. A total of 761 loops are identified, of which 346 are eddies, whereas the loops identified from loopers are only 149. Larger radii loops and eddies are observed in the western and central Bay of Bengal (BoB) and the southwestern part of the Arabian Sea (AS). Temporal variation of loops and eddies shows a peak during April—May in the AS and September—October in the BoB. In the BoB, the temporal variation of cyclonic eddies matches with the variation in chlorophyll
Źródło:
Oceanologia; 2021, 63, 4; 516-530
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hardening-related deformations of gear wheels after vacuum carburising and quenching in gas
Autorzy:
Stachurski, W.
Zgórniak, P.
Sawicki, J.
Przybysz, M.
Powiązania:
https://bibliotekanauki.pl/articles/103173.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
gas quenching
geometric measurement
hardening-related deformations
gear wheels
Opis:
The purpose of modern surface hardening technology is obtaining reproducible, precisely planned parameters of the carburized layer, minimizing the negative phenomena that result in dimensional changes after hardening and making it possible to determine the nature and magnitude of these changes. This concerns mainly the concept of single-piece flow in heat treatment applied for the purposes of mass production, employing a special autonomous 4D Quenching chamber for high pressure gas quenching (HPGQ). The main components of the 4D Quenching chamber include a system of cooling nozzles surrounding the processed item and providing a uniform inflow of cooling gas from all directions (3D) and a table rotating together with the item processed, contributing to uniform cooling (4D). Within the framework of this paper there was studied the impact of gear wheel quenching in a 4D Quenching chamber using nitrogen at pressure of 6 and 10 bar on changes in geometry. Geometric measurements of facewidth of gear, hole diameter and outside diameter were performed before and after carburization and quenching. The results obtained allowed us to determine the impact of quenching pressure inside a 4D Quenching chamber on dimensional changes in gear wheels analyzed. The thermo-chemical treatment resulted in a decrease in outside diameters and hole diameters measured and an increase in facewidth of gears.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 1; 237-245
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Force analysis and simulation – experimental research on the measurement of cylindrical surface profiles
Autorzy:
Nozdrzykowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/135450.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
energy converter crankshafts
measurement of geometric deviations
force analysis
practical application
simulations
experimental tests
Opis:
The results of tests presented herein can have practical applications for the adjustment of rotary speed to ensure constant contact between the measuring sensor’s spindle tip and the crankshaft journal of a piston energy converter, whose roundness profile is being measured. Analytical considerations have been supported by the results of simulations as well as experimental tests. The research has also shown that an increase in rotary speed affects the obtained profile shape and the value of determined roundness deviation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 48 (120); 37-42
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameters for CMM contact measurements of free-form surfaces
Autorzy:
Poniatowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/220454.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coordinate measurements
free-form surface
geometric deviations
measurement parameters
Opis:
Obtaining discrete data is inseparably connected with losing information on surface properties. In contact measurements, the ball tip functions as a mechanical-geometrical filter. In coordinate measurements the coordinates of the measurement points of a discrete distribution on the measured surface are obtained. Surface geometric deviations are represented by a set of local deviations, i.e. deviations of measurement points from the nominal surface (the CAD model), determined in a direction normal to this surface. The results of measurements depend both on the ball tip diameter and the grid size of measurement points. This article presents findings on the influence of the ball tip diameter and the grid size on coordinate measurement results along with the experimental results of measurement of a free-form milled surface, in order to determine its local geometric deviations. One section of the surface under research was measured using different measurement parameters. The whole surface was also scanned with different parameters, observing the rule of selecting the tip diameter d and the sampling interval T in the ratio of 2:1.
Źródło:
Metrology and Measurement Systems; 2011, 18, 2; 199-207
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty evaluation of multilateration-based geometric error measurement considering the repeatibility of positioning of the machine tool
Autorzy:
Liu, Xingbao
Xia, Yangqiu
Rui, Xiaoting
Powiązania:
https://bibliotekanauki.pl/articles/2206791.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sequential-multilateration
laser tracker
machine tool
geometric error
measurement uncertainty
Opis:
The sequential multilateration principle is often adopted in geometric error measurement of CNC machine tools. To identify the geometric errors, a single laser tracker is placed at different positions to measure the length between the target point and the laser tracker. However, the measurement of each laser tracker position is not simultaneous and measurement accuracy is mainly subject to positioning repeatability of the machine tool. This paper attempts to evaluate the measurement uncertainty of geometric errors caused by the positioning repeatability of the machine tool and the laser tracker spatial length measurement error based on the Monte Carlo method. Firstly, a direct identification method for geometric errors of CNC machine tools based on geometric error evaluation constraints is introduced, combined with the geometric error model of a three-axis machine tool. Moreover, uncertainty contributors caused by the repeatability of positioning of numerically controlled axes of the machine tool and the laser length measurement error are analyzed. The measurement uncertainty of the geometric error and the volumetric positioning error is evaluated with the Monte Carlo method. Finally, geometric error measurement and verification experiments are conducted. The results show that the maximum volumetric positioning error of the machine tool is 84.1 μm and the expanded uncertainty is 5.8 μm ( = 2). The correctness of the geometric error measurement and uncertainty evaluation method proposed in this paper is verified compared with the direct geometric error measurement methods.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 49--63
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation tests of the method for determining a CAD model of free-form surface deterministic deviations
Autorzy:
Poniatowska, M.
Werner, A.
Powiązania:
https://bibliotekanauki.pl/articles/221700.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coordinate measurement
geometric deviation
free-form surface
regression analysis
CAD model
Opis:
Geometric deviations of free-form surfaces are attributed to many phenomena that occur during machining, both systematic (deterministic) and random in character. Measurements of free-form surfaces are performed with the use of numerically controlled CMMs on the basis of a CAD model, which results in obtaining coordinates of discrete measurement points. The spatial coordinates assigned at each measurement point include both a deterministic component and a random component at different proportions. The deterministic component of deviations is in fact the systematic component of processing errors, which is repetitive in nature. A CAD representation of deterministic geometric deviations might constitute the basis for completing a number of tasks connected with measurement and processing of free-form surfaces. The paper presents the results of testing a methodology of determining CAD models by estimating deterministic geometric deviations. The research was performed on simulated deviations superimposed on the CAD model of a nominal surface. Regression analysis, an iterative procedure, spatial statistics methods, and NURBS modelling were used for establishing the model.
Źródło:
Metrology and Measurement Systems; 2012, 19, 1; 151-158
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methodology for measurement the energy efficiency involving solar heating systems using stochastic modelling
Autorzy:
Menita, B. G.
Medeiros, G. P.
Domingos, J. L.
Domingues, E. G.
Alves, A. J.
Faria, A. F.
Miguel, M. L. S.
Calixto, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/136254.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
energy efficiency
geometric brownian motion
Monte Carlo simulation
performance measurement
verification
solar water heating
Opis:
The purpose of the present study is to evaluate gains through measurement and verification methodology adapted from the International Performance Measurement and Verification Protocol, from case studies involving Energy Efficiency Projects in the Goias State, Brazil. This paper also presents the stochastic modelling for the generation of future scenarios of electricity saving resulted by these Energy Efficiency Projects. The model is developed by using the Geometric Brownian Motion Stochastic Process with Mean Reversion associated with the Monte Carlo simulation technique. Results show that the electricity saved from the replacement of electric showers by solar water heating systems in homes of low-income families has great potential to bring financial benefits to such families, and that the reduction in peak demand obtained from this Energy Efficiency Action is advantageous to the Brazilian electrical system. Results contemplate also the future scenarios of electricity saving and a sensitivity analysis in order to verify how values of some parameters influence on the results, once there is no historical data available for obtaining these values.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 1; 42-51
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Формирование понятия площади плоского геометрического тела
Development of concept of square of the flat geometric body
Autorzy:
Снигур, Татьяна
Швец, Василий
Powiązania:
https://bibliotekanauki.pl/articles/442259.pdf
Data publikacji:
2016-06-30
Wydawca:
Towarzystwo Wiedzy Powszechnej w Szczecinie
Tematy:
Геометрическое тело
площадь плоского геометрического тела
измерение площади фигуры
единицы измерения
народные меры
палетка
geometric body
square of the flat geometric body
measurement of square of figures
units of measurement
national measures
measuring grid
Opis:
В статье рассмотрено формирование понятия площади как функции на множестве плоских геометрических тел. Сначала рекомендуем познакомить учащихся с историческими сведениями, фактами, связанными с вычислением площади фигуры, народными задачами, мерами и способами измерения. Это будет способствовать положительной мотивации, развитию интереса к изучению темы «Многоугольники. Площади многоугольников». Раскрытие понятия площади плоского геометрического тела предлагаем начать с практических упражнений на измерение площади с помощью палетки (для небольших по размеру геометрических плоских тел), а также задач на нахождение и сравнение площади земельных участков, квартиры, государства и т.д. После обсуждения и обобщения результатов рассмотренных задач от физических плоских объектов следует перейти к рассмотрению плоских геометрических тел: прямоугольника, параллелограмма, треугольника, ромба, трапеции, круга, которые являются математическими моделями плоских физических объектов. Только теперь можно выяснять, что понимать под площадью плоского геометрического тела и какими свойствами обладает данная геометрическая величина.
In the article we considered methodical recommendations in relation to forming for the students the concept of area of flat geometrical body as function on the plural of flat bodies. The article also shows the historical and mathematical details that contribute to the positive motivation, the development of interest in the study of the geometrical magnitude.
Źródło:
Edukacja Humanistyczna; 2016, 1; 151-159
1507-4943
Pojawia się w:
Edukacja Humanistyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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