Autor: Sowa, M. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: “gcdAlpha” – a semi-analytical method for solving fractional state equations
Autorzy:: Sowa, M.
Powiązania:: https://bibliotekanauki.pl/articles/377385.pdf
Data publikacji:: 2018
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: semi-analytical method
fractional derivative
circuit analysis
different orders
Opis:: The paper discusses a semi-analytical method for solving systems of fractional state equations with various orders. The method bases on an expansion of the system into one where there is a single derivative order. The formulation of the matrices of the new system is explained in detail. Another characteristic feature of the method is also introduced – a consideration of forms, in which the time functions appear and the terms appearing in the solution as a result. A fractional circuit example is presented in order to test the method. The computation time for the method is also studied.
Źródło:: Poznan University of Technology Academic Journals. Electrical Engineering; 2018, 96; 231-242
1897-0737
Pojawia się w:: Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Comparison of time-stepping methods for transient magnetic field computations in COMSOL Multiphysics
Autorzy:: Sowa, M.
Typańska, D.
Powiązania:: https://bibliotekanauki.pl/articles/378331.pdf
Data publikacji:: 2014
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: time-stepping
COMSOL
transient magnetic field
Opis:: The computations of a transient magnetic field problem are presented. The problem has been constructed and solved in COMSOL Multiphysics which is one of the most popular and versatile commercial programs that allow to deal with solving electromagnetic field problems by means of the finite element method. A simple 2D problem of a coaxial cable has been chosen so that an analytical solution can be used in order to easily compute an error. The main topic of the paper concerns the comparison of the time-stepping methods that are available in COMSOL Multiphysics i.e. the BDF and generalized alpha methods. It is also possible to select various options for these methods, which have an influence on the solution accuracy. These have been also considered in the analysis.
Źródło:: Poznan University of Technology Academic Journals. Electrical Engineering; 2014, 77; 141-147
1897-0737
Pojawia się w:: Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Pre-assembly for FEM 2D non-curvilinear quadrilateral Lagrangian elements
Autorzy:: Sowa, M.
Typańska, D.
Powiązania:: https://bibliotekanauki.pl/articles/97541.pdf
Data publikacji:: 2014
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: pre-assembly
finite element method
higher order elements
quadrilateral Lagrangian elements
Opis:: The paper concerns an idea of preparing auxiliary equations and data for the finite element method assembly. This is made for a specific element type and element order and is referred to as the pre-assembly. Most importantly the prepared auxiliary equations require that only the element’s placement (coordinates) needs to be known, while the remaining coefficients that are required are stored in data sheets. The pre-assembly allows programmers who implement the FEM to significantly reduce the effort put into the assembly algorithm through its replacement by a few simple equations and the application of the prepared data. These data sheets can be prepared and can be utilized by FEM programmers. The construction of these data sheets for non-curvilinear quadrilateral Lagrangian elements (of any selected order) is explained in this paper.
Źródło:: Computer Applications in Electrical Engineering; 2014, 12; 106-119
1508-4248
Pojawia się w:: Computer Applications in Electrical Engineering
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Pre-assembly of FEM n-th order triangular elements
Autorzy:: Sowa, M.
Typańska, D.
Powiązania:: https://bibliotekanauki.pl/articles/377713.pdf
Data publikacji:: 2014
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: assembly
finite element method
higher order elements
Opis:: The paper presents a method of preparing data, which can be used to simplify the procedure of formulating local stiffness matrices in the finite element method (the part of preparing this data is hence referred to as the pre-assembly). For the presentation of the methodology non-curvilinear triangular elements have been chosen, where it has been taken into account that any order can be selected for the elements. The paper presents a mathematical basis of how the auxiliary data is prepared. The appropriate relations to the final FEM equations are also given.
Źródło:: Poznan University of Technology Academic Journals. Electrical Engineering; 2014, 77; 133-139
1897-0737
Pojawia się w:: Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Analytical solution for certain nonlinear electromagnetic field problems
Autorzy:: Sowa, M.
Spałek, D.
Powiązania:: https://bibliotekanauki.pl/articles/377744.pdf
Data publikacji:: 2012
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: electromagnetic field
analytical solution
nonlinear analysis
Opis:: The paper presents a nonlinear electromagnetic field problem with cylindrical symmetry. A time-sinusoidal boundary condition is applied, which yields non-sinusoidal steady-state fields. The problem is brought forth to test an analytical-numerical method based on the method of small parameter. A distinctive feature of this method is that it requires symbolic calculations to be performed. These allow to reduce the problem to a system of nonlinear equations. In order to check the accuracy of the solution, several error criteria are introduced. Moreover, the power balance of a nonlinear conductive region is verified.
Źródło:: Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 69; 49-56
1897-0737
Pojawia się w:: Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:: Biblioteka Nauki

Artykuł

Informacja