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Wyszukujesz frazę "Nelder-Mead Method" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
An algorithm of a freeform surfaces measurement adjustment using a specification of the workpiece coordinate system location
Autorzy:
Buša, J.
Buša, J. Jr.
Dovica, M.
Fabian, M.
Ižol, P.
Honus, S.
Powiązania:
https://bibliotekanauki.pl/articles/103412.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
freeform surface
cloud of points
Nelder-Mead method
Newton method
Opis:
A difficulty of freeform surfaces evaluations lies in a setup of a coordinate measuring system in general, when it is not possible to use the standard system of alignment by a point, a line, and a surface. An algorithm for the measurement adjustment using a small workpiece coordinate system movement and rotation to achieve a smaller least square error of the produced surface for a given freeform surface defined by the function of two variables is considered. The algorithm uses the Newton method for calculation of the orthogonal distance of a measured point to a given surface and also for minimization of the sum of the distance squares. Numerical results for an example are given.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 3; 223-232
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Features of an ultra-large container ship mathematical model adjustment based on the results of sea trials
Autorzy:
Pipchenko, O. D.
Tsymbal, M.
Shevchenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/116848.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
containerization
container Ship
ultra-large container ship
zig-zag test
container shipping
mathematical model
sea trial test
Nelder-Mead Method
Opis:
The research addresses the problem of an ultra-large container ship mathematical model adjustment based on sea trials. In order to verify the model’s adequacy, simulated data had to be compared to the trial report data, which was obtained in ballast condition with significant trim. In such circumstances, model coefficients cannot be calculated by known methods and have to be corrected as per trial data. It is proposed to determine translational motion coefficients first. To get optimal results, it was also proposed to divide the objective function into kinematic and dynamic components, with each component being assigned a weighting factor. A separate objective function component was assigned to the zig-zag maneuver, which includes the first and second overshoot angles.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 1; 163-170
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of optimisation methods applied to thermal cycle of a coal fired power plant
Autorzy:
Kowalczyk, Ł.
Elsner, W.
Powiązania:
https://bibliotekanauki.pl/articles/240829.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermodynamic optimisation
Nelder-Mead method
thermal cycle
coal fired power plant
IPSEpro
optymalizacja termodynamiczna
metoda Neldera-Meada
cykl termiczny
elektrownia węglowa
Opis:
The paper presents a thermodynamic optimization of 900 MW power unit for ultra-supercritical parameters, modified according to AD700 concept. The aim of the study was to verify two optimisation methods, i.e., the finding the minimum of a constrained nonlinear multivariable function (fmincon) and the Nelder-Mead method with their own constrain functions. The analysis was carried out using IPSEpro software combined with MAT-LAB, where gross power generation efficiency was chosen as the objective function. In comparison with the Nelder-Mead method it was shown that using fmincon function gives reasonable results and a significant reduction of computational time. Unfortunately, with the increased number of decision parameters, the benefit measured by the increase in efficiency is becoming smaller. An important drawback of fmincon method is also a lack of repeatability by using different starting points. The obtained results led to the conclusion, that the Nelder-Mead method is a better tool for optimisation of thermal cycles with a high degree of complexity like the coal-fired power unit.
Źródło:
Archives of Thermodynamics; 2013, 34, 4; 175-186
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of Network Traffic Congestion Controller with PI AQM Based on ITAE Index
Autorzy:
Fajri, Misbahul
Ramli, Kalamullah
Powiązania:
https://bibliotekanauki.pl/articles/1844457.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
network congestion control
active queue management (AQM)
proportional integral controller
Nelder-Mead simplex method
integral of time-weighted absolute error (ITAE)
Opis:
Establishing the proper values of controller parameters is the most important thing to design in active queue management (AQM) for achieving excellent performance in handling network congestion. For example, the first well known AQM, the random early detection (RED) method, has a lack of proper parameter values to perform under most the network conditions. This paper applies a Nelder-Mead simplex method based on the integral of time-weighted absolute error (ITAE) for a proportional integral (PI) controller using active queue management (AQM). A TCP flow and PI AQM system were analyzed with a control theory approach. A numerical optimization algorithm based on the ITAE index was run with Matlab/Simulink tools to find the controller parameters with PI tuned by Hollot (PI) as initial parameter input. Compared with PI and PI tuned by Ustebay (PIU) via experimental simulation in Network Simulator Version 2 (NS2) in five scenario network conditions, our proposed method was more robust. It provided stable performance to handle congestion in a dynamic network.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 4; 715-721
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and parameter identification of vibrations of a double torsion pendulum with friction
Autorzy:
Czerwiński, E.
Olejnik, P.
Awrejcewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/387504.pdf
Data publikacji:
2015
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
friction
planar contact
numerical modeling
double torsion pendulum
parameter identification
nonlinear vibrations
kinematic excitation
kinematic forcing mechanism
nelder-mead method
tarcie
modelowanie numeryczne
wahadło podwójne skręcane
identyfikacja parametrów
drgania nieliniowe
wzbudzanie kinematyczne
metoda Neldera-Meada
Opis:
The purpose of this paper is to investigate a double torsion pendulum with planar frictional contact. The single torsion pendulum with one-degree-of-freedom is an angular equivalent of the linear harmonic oscillator. The second degree of freedom has been obtained by adding a free body to the inverted single torsion pendulum. The free body’s angular displacement is caused by frictional forces appearing in the interface (contact zone) between the free body and the pendulum column’s head kinematically excited at its base by a mechanism with torsion spiral spring. An experimental station has been set up and run to find most unknown parameters of the pendulum from the time series of state variables taken as inputs to the Nelder-Mead method of identification. The obtained results proved significant usability of the identification method in the case of numerical simulation of the pendulum’s dynamical model. It has not been satisfactorily proved in the case of time characteristics coming from a real system that exhibits also some unrecognized physical effects.
Źródło:
Acta Mechanica et Automatica; 2015, 9, 4; 204-212
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody simpleksów w badaniach symulacyjnych mikrozaworu hydraulicznego
Application of the simplex method in simulation research of hydraulic microvalve
Autorzy:
Łomotowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/131362.pdf
Data publikacji:
2018
Wydawca:
Uczelnia Jana Wyżykowskiego
Tematy:
metoda simpleksów
modyfikacja Neldera-Meada
optymalizacja
mikrozawór hydrauliczny
simplex method
Nelder-Mead modification
optimization
hydraulic microvalve
Opis:
W artykule krótko opisano metodę simpleksów - prostą metodę poszukiwania optymalnych parametrów procesu, maszyny czy urządzenia. Pokazano, że metoda simpleksów, powszechnie stosowana w technologii chemicznej, może również być wykorzystana w budowie i eksploatacji maszyn. Przedstawiono przykład wykorzystania metody simpleksów do badań symulacyjnych mikrozaworu hydraulicznego, których celem był dobór najlepszych parametrów geometrycznych elementu domykającego i sztywności sprężyny.
The paper briefly describes the simplex method - a simple method of searching for the optimal process, machine or device parameters. It has been shown that the simplex method commonly used in chemical technology can also be applied to the construction and operation of machines. An example of using the simplex method for simulation research of a hydraulic microvalve was presented. The purpose of the tests was to select the best geometric parameters of the closing element and spring stiffness.
Źródło:
Zeszyty Naukowe Uczelni Jana Wyżykowskiego. Studia z Nauk Technicznych; 2018, 7; 47-59
2543-6740
Pojawia się w:
Zeszyty Naukowe Uczelni Jana Wyżykowskiego. Studia z Nauk Technicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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