Informacja

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

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "variable" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-13 z 13
    Tytuł:
    Variable order 3D models of bone remodelling
    Autorzy:
    Valério, D.
    Neto, J.
    Vinga, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/202197.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    variable-order derivative
    bone remodelling
    cancer
    przebudowa kości
    rak
    Opis:
    This paper presents simulations of a three-dimensional model of the bone remodelling process. The model consists of a set of variable order partial differential equations, in which the varying order depends on the presence of tumour cells. The simulations are of a two-dimensional bone, to make visualisation simpler. They show that this model corresponds to the known evolution of bone remodelling, and is simpler than integer order models found in the literature.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 3; 501-508
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Development of variable rate sprayer for oil palm plantation
    Autorzy:
    Ishak, W.
    Hudzari, R.
    Ridzuan, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/200163.pdf
    Data publikacji:
    2011
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    smart sprayer
    variable rate
    camera vision
    weedicide
    oil palm
    Opis:
    This project describes the design and development of a camera vision with color detection for the variable rate technology (VRT) automated sprayer. In this project, the smart sprayer system was already developed and mounted on the ATV. The automated sprayer system was developed by combination of the electromechanical system, PC parallel port relay board, the controller and visual basic programming software. This smart sprayer system is guided with the camera to detect the presence of weeds. Detection of weeds is based on the green color value from RGB value. The amount or percentage (%) of weeds detected determines the rate of spraying that is controlled by an electric motor and the relay board. In this project, the spray nozzles were modified to be fully open, fully closed and half open. The closing and opening of valves were controlled by the electromechanical system that receives the instruction from the camera vision. Experiments carried out shows that the nozzle is closed when the percentage of weeds detected is less than 2%. It is half open at 3% to 50% and fully open at more than 51%. The application rate of spraying can be determined from the result of the spraying operation.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 3; 299-302
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new form of Boussinesq equations for long waves in water of non-uniform depth
    Autorzy:
    Szmidt, J.
    Hedzielski, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/201637.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    long wave
    Boussinesq equation
    wave transformation
    variable water depth
    Opis:
    The paper describes the non-linear transformation of long waves in shallow water of variable depth. Governing equations of the problem are derived under the assumption that the non-viscous fluid is incompressible and the fluid flow is a rotation free. A new form of Boussinesq-type equations is derived employing a power series expansion of the fluid velocity components with respect to the water depth. These non-linear partial differential equations correspond to the conservation of mass and momentum. In order to find the dispersion characteristic of the description, a linear approximation of these equations is derived. A second order approximation of the governing equations is applied to study a time dependent transformation of waves in a rectangular basin of water of variable depth. Such a case corresponds to a spatially periodic problem of sea waves approaching a near-shore zone. In order to overcome difficulties in integrating these equations, the finite difference method is applied to transform them into a set of non-linear ordinary differential equations with respect to the time variable. This final set of these equations is integrated numerically by employing the fourth order Runge - Kutta method.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 3; 631-643
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Duality of variable fractional order difference operators and its application in identification
    Autorzy:
    Sierociuk, D.
    Twardy, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/201717.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    variable order fractional calculus
    duality
    identification
    rachunek z ułamkową zmienną
    dualizm
    identyfikacja
    Opis:
    The paper presents a number of definitions of variable order difference and discusses duality among some of them. The duality is used to improve the performance of the least squares estimation when applied to variable order difference fractional systems. It turns out, that by appropriate exploitation of duality one can reduce the estimator variance when system identification is carried out.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 4; 809-815
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nonlinear damage accumulation of concrete subjected to variable amplitude fatigue loading
    Autorzy:
    Chen, Y.
    Chen, X.
    Bu, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/201230.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    nonlinear damage
    variable amplitude loading
    prediction model
    concrete
    uszkodzenia
    model predykcji
    beton
    Opis:
    To account for the load sequence effect, damage fatigue models with nonlinearity in propagation and accumulation have been developed. This paper reviews five classical nonlinear fatigue models used to predict the life times of concrete under variable amplitude loadings. Experimental results from literature are used to validate the five classical prediction models. It can be found that Hilsdorf and Kesler model yields unsafe or conservative predictions, and the other four models are more suitable for predicting life times of concrete. In this paper, the author used a new nonlinear damage model based on the nonlinear continuum damage mechanics to predict fatigue life of concrete. The model considers fatigue limit, loading parameters, the unseparable characteristics for the damage parameter and the load sequence effect. The validity of the nonlinear fatigue damage model is checked against tests from literature.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 2; 157-163
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fractional variable order anti-windup control strategy
    Autorzy:
    Sierociuk, D.
    Malesza, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/200019.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    fractional calculus
    variable order
    PID control
    anti-windup
    rachunek różniczkowy
    sterowanie PID
    przebieg zmienności
    Opis:
    In this paper, a novel anti-windup strategy is presented. It is based on using fractional variable order integrator instead of integer order one in PID controller. It is shown that among four different types of variable order derivative definitions, only one gives satisfactory results – comparable, and even slightly better than the classical back-calculation anti-windup algorithm. Results are also presented in the form of simulation plots.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 4; 427-432
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new hybrid (hydro-numerical) model of the circulatory system
    Autorzy:
    Darowski, M.
    Kozarski, M.
    Ferrari, G.
    Zieliński, K.
    Górczyńska, K.
    Szczepanowski, A.
    Pałko, K. J.
    Fresiello, L.
    Di Molfetta, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/199804.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    lumped parameter circulatory model
    hybrid hydro-numerical models
    impedance transformers
    LVAD assistance
    variable elastance
    Opis:
    The paper presents a hybrid (hydro-numerical) circulatory model built to be used as a complementary tool for clinical purposes. It was developed at the Institute of Biocybernetics and Biomedical Engineering - Polish Academy of Sciences (Poland) in co-operation with the Institute of Clinical Physiology - National Council of Research (Italy). Main advantages of the model are: 1) high accuracy and repeatability of parameters setting, characteristic of numerical solutions, 2) maximum flexibility achieved by implementing the largest possible number of the model’s elements in the numerical way, 3) ability to test mechanical heart assist devices provided by special computer applications; in the model two physically different signal environments - numerical and hydraulic - are connected by special impedance transformers interfacing physical and numerical parts of the model; 4) eliminating flowmeters, as the voltage controlled flow sources embedded in the system provide information on flows. In vitro tests were performed to evaluate the circulatory model: a) modelling and simulation of physiological and pathological states parameters vs. left ventricular end-systolic elastance (Emax l) and rest volume (Vol) variations, b) testing the effect of LVAD counterpulsation on circulatory hemodynamics and ventricular energetics; it resulted in the increase of total cardiac output (COLV tot) from pathological value 3.8 to 5.4 l·min−1, mean aortic pressure mPas from 67.8 to 96.1 mmHg and in the decrease of left atrial pressure mPla from 15.7 to 7.7 mmHg and External Work nEW by 37.5%. The model was verified based on literature data.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 993-1003
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hypothetical analysis for peristaltic transport of metallic nanoparticles in an inclined annulus with variable viscosity
    Autorzy:
    Nadeem, S.
    Sadaf, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/201426.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    inclined annulus
    viscous nanofluid
    peristaltic flow
    variable viscosity
    exact solution
    pierścień
    nanofluid
    przepływ perystaltyczny
    dokładne rozwiązanie
    Opis:
    The main objective of this article is to present a mathematical model for peristaltic transport in an inclined annulus. In this analysis, two-dimensional flow of a viscous nanofluid is observed in an inclined annulus with variable viscosity. Copper as nanoparticle with blood as its base fluid has been considered. The inner tube is unifom or rigid, while the outer tube takes a sinusoidal wave. Governing equations are solved under the well-known assumptions of low Reynolds number and long-wavelength. Exact solutions have been established for both velocity and nanoparticle temperature. The features of the peristaltic motion are explored by plotting graphs and discussed in detail.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 2; 447-454
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical solution of fractional variable order linear control system in state-space form
    Autorzy:
    Malesza, W.
    Macias, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/201996.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    variable order fractional calculus
    differential equations
    analog modeling
    równania różniczkowe
    modelowanie analogowe
    rachunek różniczkowy ułamkowego rzędu
    Opis:
    The aim of this paper is to introduce a matrix approach for approximate solving of non-commensurate fractional variable order linear control systems in state-space form. The approach is based on switching schemes that realize variable order derivatives. The obtained numerical solution is compared with simulation and analog model results.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 5; 715-724
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new sensorless speed control structure for PMSM using reference model
    Autorzy:
    Urbanski, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/199989.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    permanent magnet motors
    sensorless control
    observers
    variable speed drives
    PMSM
    bezczujnikowa kontrola
    obserwator
    napędy o zmiennej prędkości
    Opis:
    In the paper a new sensorless control structure for the PMSM drive is presented. Such a structure is especially recommended for speed in the range of single revolutions per second (excluding standstill). The method uses a back EMF observer for position estimation. However, there is no need to estimate the speed. This is a big advantage because of possible irregularity of estimated back EMF in this speed range, which makes the calculation of speed difficult or impossible. The proposed structure is similar to the model following control, but the reference model attempts to track the motor operating point. The main idea is to utilize as a reference a model of the whole drive, including speed and current controllers and motor model. Such a model produces reference voltage for the real inverter. However, an extra unit – called rotator – is needed to provide precise control of direct axis current, which is sensitive to the improper position of the voltage vector. The rotator acts as a kind of compensator for error of position estimation.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 4; 489-496
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Efficient learning variable impedance control for industrial robots
    Autorzy:
    Li, C.
    Zhang, Z.
    Xia, G.
    Xie, X.
    Zhu, Q.
    Powiązania:
    https://bibliotekanauki.pl/articles/200716.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    variable impedance control
    reinforcement learning
    efficient
    Gaussian process
    industrial robots
    impedancja
    poprawa efektywności
    wydajność
    model Gaussa
    roboty przemysłowe
    Opis:
    Compared with the robots, humans can learn to perform various contact tasks in unstructured environments by modulating arm impedance characteristics. In this article, we consider endowing this compliant ability to the industrial robots to effectively learn to perform repetitive force-sensitive tasks. Current learning impedance control methods usually suffer from inefficiency. This paper establishes an efficient variable impedance control method. To improve the learning efficiency, we employ the probabilistic Gaussian process model as the transition dynamics of the system for internal simulation, permitting long-term inference and planning in a Bayesian manner. Then, the optimal impedance regulation strategy is searched using a model-based reinforcement learning algorithm. The effectiveness and efficiency of the proposed method are verified through force control tasks using a 6-DoFs Reinovo industrial manipulator.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 2; 201-212
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of high-speed camera measurements for determination of energy losses generated in a vibrating belt of CVT transmission
    Autorzy:
    Łatas, Waldemar
    Kot, Adam
    Powiązania:
    https://bibliotekanauki.pl/articles/27311437.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    continuously variable transmission
    moving beam vibrations
    high-speed camera
    power losses
    straty mocy
    przekładnia bezstopniowa
    kamera szybka
    drgania belki sprężystej
    Opis:
    The paper presents a proposition of the theoretical-experimental method of determination of power losses in the transversely vibrating rubber V-belt of continuously variable transmission. The article comprises the results of experimental tests conducted on a special test stand with a complete scooter drivetrain powered by a small two-stroke internal combustion engine. Such a configuration allows ensuring real CVT working conditions. A high-speed camera was used for the contactless measurement of belt vibrations and time-lapse image analysis was performed in dedicated software. An axially moving Euler–Bernoulli beam was assumed as the mathematical model. Longitudinal vibrations and nonlinear effects were omitted. Additionally, it was assumed that the belt material behaves according to the Kelvin–Voigt rheological model. Analysis of the damped free vibrations of the cantilever beam, made of the belt segment, allowed to determine the equivalent bending damping coefficient. The CVT power losses, due to bending in the rubber transmission belt, were obtained for the fixed working conditions after numerical calculations. The proposed methodology is a new approach in this research area, which allows to obtain results impossible to achieve with other measurement methods.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 5; art. no. e146238
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Electric shock hazard in circuits with variable-speed drives
    Autorzy:
    Czapp, S.
    Guzinski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/199800.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    variable speed drives
    earth fault currents
    power electronics converters
    protection against electric shock
    residual current devices
    napędy o zmiennej prędkości
    prądy ziemnozwarciowe
    zabezpieczenia przed porażeniem elektrycznym
    przekształtnik energoelektryczny
    Opis:
    The conventional approach to electrical safety under fault condition in typical power systems considers earth fault currents of sinusoidal waveform and frequency of 50‒60 Hz. However, in circuits with variable-speed drives, there is earth fault current flow with harmonics, and these harmonics influence the threshold of ventricular fibrillation. The paper presents earth fault current waveforms in circuits with variable-speed drives without inverter output (motor) filter and with one of the two types of inverter output filters being used. The details of both filters are presented, and the effect of harmonics of earth fault current on ventricular fibrillation is evaluated. Furthermore, the effect of harmonics, which occurs in circuit of variable-speed drive, on the tripping current of residual current devices is presented. Residual current devices may be utilized to ensure protection against direct and indirect contact, but limitations in their proper operation, due to harmonics, may exist. Operational characteristics of a proposed residual current device dedicated to circuits with earth fault current containing harmonics, as in the variable-speed circuits, are presented.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 3; 361-372
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-13 z 13

      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