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Wyszukujesz frazę "method of calculation" wg kryterium: Wszystkie pola


Tytuł:
Method of calculation flexural stiffness over natural oscillations frequencies
Autorzy:
Nesterenko, A.
Stolpovskiy, G.
Nesterenko, M.
Powiązania:
https://bibliotekanauki.pl/articles/230336.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamika
system budowlany
częstotliwość
drgania naturalne
sztywność na zginanie
metoda elementów skończonych
dynamics
building system
frequency
natural oscillations
flexural stiffness
finite element method
Opis:
The actual load-bearing capacity of elements of a building system can be calculated by dynamic parameters, in particular by resonant frequency and compliance. The prerequisites for solving such a problem by the finite element method (FEM) are presented in the article. First, modern vibration tests demonstrate high accuracy in determination of these parameters, which reflects reliability of the diagnosis. Secondly, most modern computational complexes do not include a functional for calculating the load-bearing capacity of an element according to the input values of resonance frequencies. Thirdly, FEM is the basis for development of software tools for automating the computation process. The article presents the method for calculating flexural stiffness and moment of inertia of a beam construction system by its own frequencies. The method includes calculation algorithm realizing the finite element method.
Źródło:
Archives of Civil Engineering; 2018, 64, 4/I; 89-103
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A refined method for the calculation of steel losses at alternating current
Autorzy:
Zagirnyak, Mykhaylo
Prus, Viacheslav
Rodkin, Dmitro
Zachepa, Yurii
Chenchevoi, Volodymyr
Powiązania:
https://bibliotekanauki.pl/articles/141089.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
domain structure
hysteresis loop
saturation degree
steel losses
Opis:
The ways of the improvement of the method for the determination of steel losses in the electrical devices of basic types are substantiated. The method is refined by taking into account the magnetic system properties at high saturation. The presence of the interrelation between the special features of the domain structure movement and the shape of the hysteresis loop is proved for laminated cores. It enabled the explanation of the causes for the abnormally high values of the losses in the steel and the atypical shapes of the hysteresis loops at its high saturation. The empiric dependence for the determination of steel losses is obtained. It provides for the high convergence of the calculated and experimental data at the actual degree of saturation and can be used in the direct-current operation of the analyzed devices.
Źródło:
Archives of Electrical Engineering; 2019, 68, 2; 295-308
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved calculation method of inductance and capacitances in ?1 circuits for resonant power amplifiers
Autorzy:
Modzelewski, J.
Kulma, K.
Powiązania:
https://bibliotekanauki.pl/articles/140508.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induktorowy współcynnik jakości
klasa A
klasa AB
klasa B
klasa C
resonant-circuit design
impedance transformation
inductor quality factor
loaded quality factor
Class A
class AB
class B
class C
Opis:
In the paper an improved method of calculation of the inductance and capacitances in the ?1 circuit for Class A, AB, B, and C resonant power amplifiers is presented. This method is based on an assumption that the quality factor of the inductor is inite and the capacitors are lossless. The input parameters for calculations are the amplifier load resistance, the transistor load resistance, the quality factor of the inductor, the loaded quality factor of the designed circuit, and the operating frequency. The presented method allows reducing the required regulation range of ?1 circuits elements In built resonant amplifiers as compared to the traditional calculation methods assuming lossless capacitors and inductor. This advantage is important, in particular, for long- and medium-wave transistor power amplifiers, where capacitances in ?1 circuits are high comparing to typical trimming capacitors.
Źródło:
Archives of Electrical Engineering; 2012, 61, 2; 221-237
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The assessment of the calculation method for determining characteristics of one straight fin labyrinth sea
Autorzy:
Szymański, A.
Dykas, S.
Majkut, M.
Strozik, M.
Powiązania:
https://bibliotekanauki.pl/articles/175271.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
Computational Flow Dynamics (CFD)
seal
smooth
turbomachinery
leakage flow rate
Opis:
The method for the selection of a calculation scheme for the evaluation of the flow behaviour of labyrinth seal with one straight fin, against smooth wall, was presented. Experimental results were obtained from measurement data carried out on the in house, vacuum test section. The advantage of the test rig is a circular shape of the labyrinth specimen, providing similar shape to configuration operated in practise. In computational fluid dynamics study different types of mesh resolution were tested, with variable volume discretization in the area of a labyrinth fin tip. Moreover, a wide range of turbulence models basing on k-ε and k-ω, exploiting the (Reynolds Average Navier Stokes) scheme, for the flow pattern evaluation, were examined. All obtained results were compared with literature data, covering research conducted on similar configurations. The presented study shows challenges as well as the possibilities of calculation simplification and compares results obtained by means of simulations and experiment. The proposed method is characterised by excellent agreement of computational results with experiment data.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 134; 89-107
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation method of branch reactances in an electrical network using short-circuit current values
Metoda obliczania reaktancji gałęzi sieci elektroenergetycznej w oparciu o wartości prądów zwarciowych
Autorzy:
Kanicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/172899.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sieć elektroenergetyczna
prądy zwarciowe
electrical network
short-circuits
Opis:
It is possible to determine branch reactances of a network when only short-circuit values are known. The paper presents the derivation of formulae for calculating branch reactances for symmetrical components. The results of short-circuit current flows of the first degree in all nodes (i.e. currents around each node) constitute a base for determining these reactances. The presented formulae do not take into consideration magnetic couplings occurring in parallel lines. Testing calculations prove that the branch reactances determined by means of such a method represent short-circuit currents with high accuracy. Such formulae have not been described so far.
W sytuacji, gdy znamy jedynie wyniki obliczeń prądów zwarciowych można, wyznaczyć reaktancje gałęzi rozpatrywanej sieci. Referat przedstawia wyprowadzone wzory na obliczenia reaktancji gałęzi dla składowych symetrycznych. Wyniki rozpływów pierwszego stopnia prądu zwarciowego we wszystkich węzłach (tzn. prądy wokół każdego z węzłów) są podstawą do wyprowadzenia tych reaktancji. Prezentowane wzory nie uwzględniają sprzężeń magnetycznych, występujących w liniach równoległych. Obliczenia sprawdzające potwierdzają, że tak wyznaczone reaktancje gałęzi z dużą dokładnością odwzorowują prądy zwarciowe w rozpatrywanej sieci elektroenergetycznej. W znanej dotychczas literaturze brak jest tego typu wzorów.
Źródło:
Archiwum Energetyki; 2011, 41, 1; 3-11
0066-684X
Pojawia się w:
Archiwum Energetyki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new prediction model of surface subsidence with cauchy distribution in the coal mine of thick topsoil condition
Autorzy:
Jiang, Yue
Misa, Rafał
Tajduś, Krzysztof
Sroka, Anton
Jiang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/219750.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wydobycie węgla
osiadanie powierzchni
rozkład Cauchy'ego
model obliczeniowy
coal mining
thick topsoil
surface subsidence
Probability Integral Method
Cauchy distribution
calculation model
Opis:
Coal is the main energy source in China, but its underground mining causes surface subsidence, chich seriously damages the ecological and living environments. How to calculate subsidence accurately is a core issue in evaluating mining damage. At present, the most commonly used method of calculation is the Probability Integral Method (PIM), based on a normal distribution. However, this method has limitations in thick topsoil (thickness > 100 m), in that the extent of the calculated boundary of the subsidence basin is smaller than its real extent, and this has an undoubted impact on the accurate assessment of the extent of mining damage. Therefore, this paper introduces a calculation model for surface subsidence based on a Cauchy distribution for thick topsoil conditions. This not only improves the accuracy of calculation at the subsidence basin boundary, but also provides a universal method for the calculation of surface subsidence.
Źródło:
Archives of Mining Sciences; 2020, 65, 1; 147-158
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The results of analyses of deep excavation walls using two different methods of calculation
Wyniki analiz obudów głębokich wykopów uzyskane z dwóch różnych metod obliczeniowych
Autorzy:
Krasiński, A.
Urban, M.
Powiązania:
https://bibliotekanauki.pl/articles/230509.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
obudowa wykopu
wykop głęboki
analiza numeryczna
metoda obliczeniowa
parcie gruntu
deep excavation
excavation wall
numerical analysis
calculation method
earth pressure
Opis:
Deep excavation walls can be analyzed and calculated by using classical methods (currently rarely in use due to their many simplifications) or numerical methods. Among the numerical methods we can distinguish a simplified approach, in which the interaction between soil and a wall structure is modelled by a system of elasto-plastic supports, and the finite-element method (FEM) in which the soil is modelled with mesh of elements. It is a common view that if we want to analyze only wall constructions, the first, simplified method of calculation is sufficient. The second method, FEM, is required if we want to further analyze the stress and strain states in the soil and the influence of the excavation on the surrounding area. However, as it is demonstrated in the paper, important differences may appear in the calculation results of both methods. Thus, the safety design of a deep excavation structure depends very much on the choice of calculating method.
Obudowy głębokich wykopów można analizować i obliczać przy użyciu metod standardowych (analitycznych - obecnie nie stosowanych ze względu na znaczne uproszczenia) lub numerycznych. Wśród metod numerycznych możemy wyróżnić rozwiązanie uproszczone, w którym współpraca pomiędzy gruntem i ścianą obudowy wyrażona jest za pomocą systemu podpór sprężysto-plastycznych oraz metodę elementów skończonych (MES), w której grunt modelowany jest za pomocą siatki elementów. Powszechnie uważa się, że do analizy samej konstrukcji obudowy wystarczająca jest metoda pierwsza, uproszczona. Druga metoda, MES, jest wymagana wówczas gdy dodatkowo chcemy przeanalizować stany naprężenia i odkształcenia w ośrodku gruntowym oraz określić oddziaływanie wykopu na otoczenie. Jednak jak pokazano w artykule, w wynikach obliczeń z obu metod mogą pojawić się znaczne rozbieżności. Bezpieczeństwo projektowania konstrukcji obudów głębokich wykopów w dużym stopniu zależy więc od wyboru metody obliczeniowej.
Źródło:
Archives of Civil Engineering; 2011, 57, 1; 59-72
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the output characteristics of photovoltaic arrays under partial shading conditions based on peak point approximate calculation method
Autorzy:
Wei, Liming
Li, Kaikai
Powiązania:
https://bibliotekanauki.pl/articles/2086691.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
– characteristic equation
peak point approximate calculation method
peak voltage point
shadow occlusion’s rate
type of illumination distribution
Opis:
The mismatch effect of photovoltaic (PV) arrays due to different illumination intensity has a significant impact on the output characteristics and output power of PV arrays, which is crucial to understand the output characteristics of PV arrays and optimize the array configuration in order to improve the value of the maximum power point. This paper illustrates the short-circuit current mismatch of series circuits, and the open-circuit voltage mismatch of parallel circuits and proposes corresponding solutions for each mismatch phenomenon. The output characteristics of multi-stage series PV arrays and multi-stage parallel PV arrays under complex illumination are analyzed by using the peak point approximation calculation method, and the distribution law of peak voltage points as well as the I-V (Current-Voltage) characteristic equation of each operating section are proposed. On this basis, the output characteristics of 3 x 3 centralized PV arrays are analyzed and verified by simulation. By comparing series and parallel PV arrays with the same condition, as well as several groups of centralized PV arrays with the same topology and different types of illumination distribution, this paper proposes a configuration optimization method for PV arrays. Matlab/Simulink simulation results confirm that the output power of parallel arrays is greater than that of series arrays under the same configuration and illuminationt distribution type, and the peak point is less than that of series arrays under the same configuration and lighting conditions; while in centralized PV arrays, the fewer series modules are shaded, the greater the output power and the less the peak point.
Źródło:
Archives of Electrical Engineering; 2022, 71, 2; 409--424
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Plate Discretization on Accuracy of the Sound Radiation Efficiency Measurements
Autorzy:
Kolber, K.
Snakowska, A.
Kozupa, M.
Powiązania:
https://bibliotekanauki.pl/articles/177333.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound radiation efficiency
sound radiation from plates
discrete calculation method
Opis:
This paper deals with the problem of the effect of discretization level and certain other parameters characterizing the measurement setup on accuracy of the process of determination of the sound radiation efficiency by means of the Discrete Calculation Method (DCM) described by Hashimoto (2001). The idea behind DCM consists in virtual division of an examined sound radiating structure into rectangular elements each of which is further assumed to contribute to the total radiation effect in the same way as a rigid circular piston having the surface area equal to this of the corresponding virtual element and vibrating in an infinite rigid baffle. The advantage of the method over conventional sound radiation efficiency measurement techniques consists in the fact that instead of acoustic pressure values, source (plate) vibration velocity amplitude values are measured in a selected number of regularly distributed points. In many cases, this allows to determine the sound radiation efficiency with sufficient accuracy, especially for the low frequency regime. The key part of the paper is an analysis of the effect of discretization level (i.e. the choice of the number of points at which vibration amplitude measurements are to be taken with the use of accelerometers) on results obtained with the use of the method and their accuracy. The problem of determining an optimum level of discretization for given excitation frequency range is a very important issue as the labor intensity (time-consuming aspect) of the method is one of its main flaws. As far as the technical aspect of the method is concerned, two different geometrical configurations of the measurement setup were tested.
Źródło:
Archives of Acoustics; 2014, 39, 4; 511-518
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation Models for Acoustic Analysis of St. Elizabeth of Hungary Church in Jaworzno Szczakowa
Autorzy:
Kosała, K.
Powiązania:
https://bibliotekanauki.pl/articles/177877.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic quality
index method
church acoustics
Singular Value Decomposition
SVD
acoustic simulation tests
Opis:
In parallel with research conducted using conventional methods, a uniform index method for assessing the acoustic quality of Roman Catholic churches has been developed. The latest version of the index method has been created using the index observation matrix of 12 churches which have been rated by means of the single number global index. Assessments of the acoustic quality of any Roman Catholic church, using two calculation models: the Global Acoustic Properties Index (GAP) and the Global Index (GI), are shown in the article. The verification was performed on the example of one church, showing the way of calculating global indices to assess the acoustic quality of a new facility. The next stages in the development of the index method for assessing the acoustic quality of churches were taking into account the audience, using simulation tests and determining the spatial distribution of the single number GAP index in an examined church. An attempt to use the GAP and GI calculation models to assess the acoustic properties of some churches is also shown in the article.
Źródło:
Archives of Acoustics; 2016, 41, 3; 485-498
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Melting and the Debye Temperature of for BCC and FCC Metals Under Pressure: A Calculation from the Statistical Moment Method
Autorzy:
Hoc, Nguyen Quang
Tinh, Bui Duc
Hien, Nguyen Duc
Powiązania:
https://bibliotekanauki.pl/articles/2174555.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
statistical moment method
defective cubic metals
perfect cubic metals
Debye temperature
Opis:
We build the melting theory and the theory of the Debye temperature for defective and perfect cubic metals mainly based on the statistical moment method. Our theoretical results are applied to metals Ni, Pd and Pt. Our calculations of melting temperatures agree well with experiments and other calculations. Our other calculations are highly reliable.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1227--1234
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Working temperature calculation of single-core cable by nonlinear finite element method
Autorzy:
Meng, Xiaokai
Han, Peijie
Liu, Yongxin
Lu, Zhumao
Jin, Tao
Powiązania:
https://bibliotekanauki.pl/articles/141018.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cable
finite element simulation model
thermal conductivity
operating temperature
Opis:
By simulating the actual working conditions of a cable, the temperature variation rule of different measuring points under different load currents was analyzed. On this basis, a three-dimensional finite element model (FEM) was established, and the difference and influence factors between the simulation temperature and the experimental measured value were discussed, then the influence of thermal conductivity on the operating temperature of the conductor layer was studied. Finally, combined with the steady-state thermal conductivity model and the experimental measured data, the relation between thermal conductivity and load current was obtained.
Źródło:
Archives of Electrical Engineering; 2019, 68, 3; 643-656
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of interval damping ratio under uncertain load in power system
Autorzy:
Xing, J.
Chen, C.
Wu, P.
Powiązania:
https://bibliotekanauki.pl/articles/201058.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power system
low frequency oscillation
interval load
interval damping ratio
successive linear programming method
Opis:
The problem of small-signal stability considering load uncertainty in power system is investigated. Firstly, this paper shows attempts to create a nonlinear optimization model for solving the upper and lower limits of the oscillation mode’s damping ratio under an interval load. Then, the effective successive linear programming (SLP) method is proposed to solve this problem. By using this method, the interval damping ratio and corresponding load states at its interval limits are obtained. Calculation results can be used to evaluate the influence of load variation on a certain mode and give useful information for improvement. Finally, the proposed method is validated on two test systems.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 151-158
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scaling laws for the FE solutions of induction machines
Autorzy:
Nell, Martin
Lenz, Jonas
Hameyer, Kay
Powiązania:
https://bibliotekanauki.pl/articles/141030.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
evolutionary strategy
finite element method analysis
induction machine
induction motor
loss calculation
multi-objective optimization
scaling laws
Opis:
In this paper a scaling approach for the solution of 2D FE models of electric machines is proposed. This allows a geometrical and stator and rotor resistance scaling as well as a rewinding of a squirrel cage induction machine enabling an efficient numerical optimization. The 2D FEM solutions of a reference machine are calculated by a model based hybrid numeric induction machine simulation approach. In contrast to already known scaling procedures for synchronous machines the FEM solutions of the induction machine are scaled in the stator-current-rotor-frequency-plane and then transformed to the torque-speed-map. This gives the possibility to use a new time scaling factor that is necessary to keep a constant field distribution. The scaling procedure is validated by the finite element method and used in a numerical optimization process for the sizing of an electric vehicle traction drive considering the gear ratio. The results show that the scaling procedure is very accurate, computational very efficient and suitable for the use in machine design optimization.
Źródło:
Archives of Electrical Engineering; 2019, 68, 3; 677-695
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Równoległe ścieżki emerytalne – koncepcja kalkulacji świadczeń dla osób z różnych typów gospodarstwa domowego
Autorzy:
Jajko-Siwek, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/473394.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pension
calculation method
rate of return
classification trees
emerytura
kalkulacja świadczenia emerytalnego
stopa zastąpienia
drzewo klasyfikacyjne
Opis:
Polski system emerytalny preferuje osoby, które długo pracują i uzyskują wysokie wynagrodzenia. Tylko tacy uczestnicy systemu uzyskają dostatecznie wysokie świadczenia. System nie uwzględnia faktu występowania zróżnicowanych typów gospodarstwa domowego, z którym wiążą się różne oczekiwania i możliwości w trakcie cyklu życia przyszłych emerytów. Celem artykułu jest prezentacja zróżnicowanych koncepcji kalkulacji świadczeń emerytalnych dla osób z różnych typów gospodarstwa, uwzględniających zróżnicowane preferencje tych osób. W oszacowaniach położono szczególny nacisk na kwestie dzietności, wskazując na wyjątkowo trudną sytuację rodzin z dużą liczbą dzieci i akcentując potrzebę powiązania poziomu emerytury z liczbą posiadanych dzieci. Podstawową zmienną, na której przeprowadzono analizy, była stopa zastąpienia wynagrodzenia świadczeniem emerytalnym. Stopy zastąpienia poddano ocenie za pomocą drzew klasyfikacyjnych.
The pension system in Poland favours persons which work long and obtain the high wage. The main aim of this paper is to present the diversified concepts of the pension benefits calculation depending on the type of the household. The special attention is paid to the problem of fertility, because of particularly difficult situation of families with high number of children. Analysis were carried out with a replacement rate as a basic indicator. In the second step various replacement rates were assessed with help of classification trees.
Źródło:
Problemy Polityki Społecznej. Studia i Dyskusje; 2015, 29(2); 35-46
1640-1808
Pojawia się w:
Problemy Polityki Społecznej. Studia i Dyskusje
Dostawca treści:
Biblioteka Nauki
Artykuł

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