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Wyszukujesz frazę "transfer function" wg kryterium: Temat


Tytuł:
Hybrid binary whale optimization algorithm based on taper shaped transfer function for software defect prediction
Hybrydowy, binarny algorytm WOA oparty na transmitancji stożkowej do prognozowania defektów oprogramowania
Autorzy:
Alnaish, Zakaria A. Hamed
Hasoon, Safwan O.
Powiązania:
https://bibliotekanauki.pl/articles/27315468.pdf
Data publikacji:
2023
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
feature selection
binary whale optimization algorithm
taper-shaped transfer function
software defect prediction
wybór cech
algorytm optymalizacji binarnej
transmitancja stożkowa
przewidywanie defektów oprogramowania
Opis:
Reliability is one of the key factors used to gauge software quality. Software defect prediction (SDP) is one of the most important factors which affectsmeasuring software's reliability. Additionally, the high dimensionality of the features has a direct effect on the accuracy of SDP models.The objective of this paper is to propose a hybrid binary whale optimization algorithm (BWOA) based on taper-shape transfer functions for solving feature selection problems and dimension reduction with a KNN classifier as a new software defect prediction method. In this paper, the values of a real vector that representsthe individual encoding have been converted to binary vector by using the four types of Taper-shaped transfer functionsto enhance the performance of BWOA to reduce the dimension of the search space. The performance of the suggestedmethod (T-BWOA-KNN)was evaluatedusing eleven standard software defect prediction datasets from the PROMISE and NASA repositories depending on the K-Nearest Neighbor (KNN) classifier. Seven evaluation metrics have been used to assess the effectiveness of the suggested method. The experimental results have shownthat the performanceof T-BWOA-KNNproduced promising results compared to other methods including ten methods from the literature, four typesof T-BWOAwith the KNN classifier. In addition, the obtained results are compared and analyzed with other methods from the literature in termsof the average numberof selected features (SF) and accuracy rate (ACC) using the Kendall W test. In this paper, a new hybrid software defect prediction methodcalledT-BWOA-KNNhas been proposed which is concerned with the feature selection problem. The experimental results have provedthatT-BWOA-KNN produced promising performance compared with other methods for most datasets.
Niezawodność jest jednym z kluczowych czynników stosowanych do oceny jakości oprogramowania.Przewidywanie defektów oprogramowania SDP (ang. Software Defect Prediction) jest jednym z najważniejszych czynników wpływających na pomiar niezawodności oprogramowania. Dodatkowo, wysoka wymiarowość cech ma bezpośredni wpływ na dokładność modeli SDP.Celemartykułu jest zaproponowanie hybrydowego algorytmu optymalizacji BWOA (ang. Binary Whale Optimization Algorithm) w oparciu o transmitancję stożkową do rozwiązywania problemów selekcji cech i redukcji wymiarów za pomocą klasyfikatora KNN jako nowej metody przewidywania defektów oprogramowania.W artykule, wartości wektora rzeczywistego, reprezentującego indywidualne kodowanie zostały przekonwertowane na wektor binarny przy użyciu czterech typów funkcji transferu w kształcie stożka w celu zwiększenia wydajności BWOA i zmniejszenia wymiaru przestrzeni poszukiwań.Wydajność sugerowanej metody (T-BWOA-KNN) oceniano przy użyciu jedenastu standardowych zestawów danych do przewidywania defektów oprogramowania z repozytoriów PROMISE i NASA w zależności od klasyfikatora KNN. Do oceny skuteczności sugerowanej metody wykorzystano siedemwskaźników ewaluacyjnych. Wyniki eksperymentów wykazały, że działanie rozwiązania T-BWOA-KNN pozwoliło uzyskaćobiecujące wyniki w porównaniu z innymi metodami, w tym dziesięcioma metodami na podstawie literatury, czterema typami T-BWOA z klasyfikatorem KNN. Dodatkowo, otrzymane wyniki zostały porównanei przeanalizowane innymi metodami z literatury pod kątem średniej liczby wybranych cech (SF) i współczynnika dokładności (ACC), z wykorzystaniem testu W.Kendalla. W pracy, zaproponowano nową hybrydową metodę przewidywania defektów oprogramowania, nazwaną T-BWOA-KNN, która dotyczy problemu wyboru cech. Wyniki eksperymentów wykazały, że w przypadku większości zbiorów danych T-BWOA-KNN uzyskała obiecującą wydajnośćw porównaniu z innymi metodami.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2023, 13, 4; 85--92
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical and simulation modeling of dual active bridge
Autorzy:
Barlik, Roman
Grzejszczak, Piotr
Koszel, Mikołaj
Powiązania:
https://bibliotekanauki.pl/articles/2173709.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dual active bridge
small-signal analysis
averaged model
transfer function
parasitics
PI controller
podwójny mostek aktywny
analiza małosygnałowa
model uśredniony
funkcja przenoszenia
pasożyty
regulator PI
Opis:
The paper is a structured, in-depth analysis of dual active bridge modeling. In the research new, profound dual active bridge converter (DAB) circuit model is presented. Contrary to already described idealized models, all critical elements including numerous parasitic components were described. The novelty is the consideration of a threshold voltage of diodes and transistors in the converter equations. Furthermore, a lossy model of leakage inductance in an AC circuit is also included. Based on the circuit equations, a small-signal dual active bridge converter model is described. That led to developing control of the input and output transfer function of the dual active bridge converter model. The comparison of the idealized model, circuit simulation (PLECS), and an experimental model was conducted methodically and confirmed the high compatibility of the introduced mathematical model with the experimental one. Proposed transfer functions can be used when designing control of systems containing multiple converters accelerating the design process, and accurately reproducing the existing systems, which was also reported in the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 5; art. no. e142653
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Testate Amoebae as Sea-level Indicators in Northwestern Norway: Developments in Sample Preparation and Analysis
Autorzy:
Barnett, Robert L.
Powiązania:
https://bibliotekanauki.pl/articles/763433.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Salt marsh, testate amoebae, sea level, transfer function, Norway, preparation
Opis:
Proxy based sea-level reconstructions are an important tool for defining past patterns of sea-level change and salt-marsh testate amoebae are a newly emerging proxy with high potential as sea-level indicators. This study develops existing analytical techniques concerned with the preparation and counting of testate amoebae for sea-level studies and demonstrates the predictive power of this group of micro-organisms. Two salt marshes in northwestern Norway were sampled for testate amoebae and multiple sub-samples were prepared using different procedures and count totals. Analytical efficiency can be improved upon by using a mild alkali, chemical disaggregant (5% KOH) to break up fibrous, salt-marsh peat and concentrate tests prior to counting. A count total of 100 individuals, rather than 150, can be used to make time gains with little or no loss of taxon information. The Norwegian salt-marsh testate amoebae showed strong zonation relative to tidal elevation. Key indicator taxa from the high marsh included Centropyxis cassis type, Cyclopyxis arcelloides type and Euglypha spp. Those from the low marsh included Difflugia pristis type and a distinctive morphotype of Centropyxis platystoma type. Combined, the two surface data sets from Norway were capable of predicting marsh surface elevations to within ± 0.09 m.
Źródło:
Acta Protozoologica; 2013, 52, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A general transfer function representation for a class of hyperbolic distributed parameter systems
Autorzy:
Bartecki, K.
Powiązania:
https://bibliotekanauki.pl/articles/330308.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
distributed parameter system
hyperbolic system
partial differential equation
transfer function
heat exchanger
układ o parametrach rozłożonych
system hiperboliczny
równanie różniczkowe cząstkowe
funkcja przeniesienia
wymiennik ciepła
Opis:
Results of transfer function analysis for a class of distributed parameter systems described by dissipative hyperbolic partial differential equations defined on a one-dimensional spatial domain are presented. For the case of two boundary inputs, the closed-form expressions for the individual elements of the 2×2 transfer function matrix are derived both in the exponential and in the hyperbolic form, based on the decoupled canonical representation of the system. Some important properties of the transfer functions considered are pointed out based on the existing results of semigroup theory. The influence of the location of the boundary inputs on the transfer function representation is demonstrated. The pole-zero as well as frequency response analyses are also performed. The discussion is illustrated with a practical example of a shell and tube heat exchanger operating in parallel- and countercurrent-flow modes.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2013, 23, 2; 291-307
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transfer function–based impulse response analysis for a class of hyperbolic systems of balance laws
Autorzy:
Bartecki, K.
Powiązania:
https://bibliotekanauki.pl/articles/206531.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
hyperbolic system
balance law
transfer function
impulse response
Laplace transform
heat exchanger
Opis:
Results of the impulse response analysis for a class of dynamical systems, described by two weakly coupled linear partial differential equations of hyperbolic type, defined on a one-dimensional spatial domain are presented. For the case of two boundary inputs of the Dirichlet type, the analytical expressions for the impulse response functions are derived based on the inverse Laplace trans form of the 2×2 transfer function matrix of the system. The influence of the boundary inputs configuration on the impulse response functions is demonstrated. The considerations are illustrated with a practical example of a thin-walled double-pipe heat exchanger operating in parallel- and countercurrent-flow modes, which correspond to the analyzed boundary conditions.
Źródło:
Control and Cybernetics; 2015, 44, 3; 327-355
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmitancje operatorowe pewnej klasy układów typu hiperbolicznego z wejściami brzegowymi
Transfer function models for a class of hyperbolic systems with boundary inputs
Autorzy:
Bartecki, K.
Powiązania:
https://bibliotekanauki.pl/articles/156137.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
układ o parametrach rozłożonych
równanie różniczkowe cząstkowe
układ hiperboliczny
transmitancja operatorowa
wymiennik ciepła
distributed parameter system
partial differential equation
hyperbolic system
transfer function
heat exchanger
Opis:
W artykule przedstawiono ogólną postać transmitancji operatorowych pewnej klasy układów o parametrach rozłożonych, opisanych dwoma równaniami różniczkowymi cząstkowymi typu hiperbolicznego. Zakładając istnienie w układzie dwóch wejść o charakterze wymuszeń brzegowych typu Dirichleta oraz dwóch wyjść rozłożonych wzdłuż osi zmiennej przestrzennej, przedstawiono wyrażenia opisujące transmitancje operatorowe układu dla dwóch różnych konfiguracji sygnałów wejściowych. Rozważania zilustrowano praktycznym przykładem wymiennika ciepła pracującego w układach: współ- oraz przeciwprądowym.
Transfer function models for a class of distributed parameter systems described by the two hyperbolic partial differential equations defined on a one-dimensional finite spatial domain are considered. Assuming two boundary inputs of Dirichlet type, the closed-form expressions for the individual elements of the 22 transfer function matrix are proposed based on the decoupled canonical representation of the system. The influence of the location of the boundary inputs on the transfer function representation is demonstrated for two different input configurations. The first one is the so-called congruent arrangement, for which both inputs act on the system at the same spatial position, l=0 (Fig. 1). The second one is the incongruent arrangement, where both inputs act on the system at its opposite ends, l=0 and l=L, respectively (Fig. 2). The considerations are illustrated with a practical example of a shell and tube heat exchanger operating in parallel- and countercurrent-flow modes (Fig. 3), which correspond to the two abovementioned boundary input configurations. Based on the transfer function model, both frequency and time responses of the system can be determined, which can be useful e.g. in the case of the model-based fault detection scheme.
Źródło:
Pomiary Automatyka Kontrola; 2014, R. 60, nr 1, 1; 49-52
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximate state-space and transfer function models for 2x2 linear hyperbolic systems with collocated boundary inputs
Autorzy:
Bartecki, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/330464.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
distributed parameter system
hyperbolic equations
approximation model
state space
transfer function
układ o parametrach rozłożonych
równanie hiperboliczne
model aproksymacyjny
przestrzeń stanu
funkcja przesyłowa
Opis:
Two approximate representations are proposed for distributed parameter systems described by two linear hyperbolic PDEs with two time- and space-dependent state variables and two collocated boundary inputs. Using the method of lines with the backward difference scheme, the original PDEs are transformed into a set of ODEs and expressed in the form of a finite number of dynamical subsystems (sections). Each section of the approximation model is described by state-space equations with matrix-valued state, input and output operators, or, equivalently, by a rational transfer function matrix. The cascade interconnection of a number of sections results in the overall approximation model expressed in finite-dimensional state-space or rational transfer function domains, respectively. The discussion is illustrated with a practical example of a parallel-flow double-pipe heat exchanger. Its steady-state, frequency and impulse responses obtained from the original infinite-dimensional representation are compared with those resulting from its approximate models of different orders. The results show better approximation quality for the “crossover” input–output channels where the in-domain effects prevail as compared with the “straightforward” channels, where the time-delay phenomena are dominating.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 3; 475-491
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trombone Transfer Functions: Comparison Between Frequency-Swept Sine Wave and Human Performer Input
Autorzy:
Beauchamp, J. W.
Powiązania:
https://bibliotekanauki.pl/articles/176612.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
brass acoustics
trombone
transfer function
nonlinear propagation
input impedance
Opis:
Source/filter models have frequently been used to model sound production of the vocal apparatus and musical instruments. Beginning in 1968, in an effort to measure the transfer function (i.e., transmission response or filter characteristic) of a trombone while being played by expert musicians, sound pressure signals from the mouthpiece and the trombone bell output were recorded in an anechoic room and then subjected to harmonic spectrum analysis. Output/input ratios of the signals’ harmonic amplitudes plotted vs. harmonic frequency then became points on the trombone’s transfer function. The first such recordings were made on analog 1/4 inch stereo magnetic tape. In 2000 digital recordings of trombone mouthpiece and anechoic output signals were made that provide a more accurate measurement of the trombone filter characteristic. Results show that the filter is a high-pass type with a cutoff frequency around 1000 Hz. Whereas the characteristic below cutoff is quite stable, above cutoff it is extremely variable, depending on level. In addition, measurements made using a swept-sine-wave system in 1972 verified the high-pass behavior, but they also showed a series of resonances whose minima correspond to the harmonic frequencies which occur under performance conditions. For frequencies below cutoff the two types of measurements corresponded well, but above cutoff there was a considerable difference. The general effect is that output harmonics above cutoff are greater than would be expected from linear filter theory, and this effect becomes stronger as input pressure increases. In the 1990s and early 2000s this nonlinear effect was verified by theory and measurements which showed that nonlinear propagation takes place in the trombone, causing a wave steepening effect at high amplitudes, thus increasing the relative strengths of the upper harmonics.
Źródło:
Archives of Acoustics; 2012, 37, 4; 447-454
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractional order PIλDµA controller design based on Bode’s ideal function
Autorzy:
Bettou, Khalfa
Charef, Abdelfatah
Powiązania:
https://bibliotekanauki.pl/articles/27312016.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Bode’s ideal transfer function
fractional order control
classical PIDA controller
fractional order PIDA controller
robustness
Opis:
The fractional order proportional, integral, derivative and acceleration (PIλDµA) controller is an extension of the classical PIDA controller with real rather than integer integration action order λ and differentiation action order µ. Because the orders λ and µ are real numbers, they will provide more flexibility in the feedback control design for a large range of control systems. The Bode’s ideal transfer function is largely adopted function in fractional control systems because of its iso-damping property which is an essential robustness factor. In this paper an analytical design technique of a fractional order PIλDµA controller is presented to achieve a desired closed loop system whose transfer function is the Bode’s ideal function. In this design method, the values of the six parameters of the fractional order PIλDµA controllers are calculated using only the measured step response of the process to be controlled. Some simulation examples for different third order motor models are presented to illustrate the benefits, the effectiveness and the usefulness of the proposed fractional order PIλDµA controller tuning technique. The simulation results of the closed loop system obtained by the fractional order PIλDµA controller are compared to those obtained by the classical PIDA controller with different design methods found in the literature. The simulation results also show a significant improvement in the closed loop system performances and robustness using the proposed fractional order PIλDµA controller design.
Źródło:
Archives of Control Sciences; 2023, 33, 2; 425--458
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extremal properties of linear dynamic systems controlled by Dirac’s impulse
Autorzy:
Białas, Stanisław
Górecki, Henryk
Zaczyk, Mieczysław
Powiązania:
https://bibliotekanauki.pl/articles/331114.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
extremal properties
Dirac's impulse
linear system
transfer function
właściwości ekstremalne
impuls Diraca
układ liniowy
funkcja przenoszenia
Opis:
The paper concerns the properties of linear dynamical systems described by linear differential equations, excited by the Dirac delta function. A differential equation of the form an x(n) (t) + ∙∙∙ a1 x’(t) + a0 x(t) = bm u (t) + ∙∙∙ + b1 u’(t) + b0 u(t) is considered with ai, bj >0. In the paper we assume that the polynomials Mn(s) = ansn + ∙∙∙ + a1s + a0 and Lm(s) = bmsm + ∙∙∙ + b1s + b0 partly interlace. The solution of the above equation is denoted by x(t, Lm, Mn). It is proved that the function x(t, Lm, Mn) is nonnegative for t ∊ (0, ∞) , and does not have more than one local extremum in the interval (0, ∞) (Theorems 1, 3 and 4). Besides, certain relationships are proved which occur between local extrema of the function x(t, Lm, Mn), depending on the degree of the polynomial Mn(s) or Lm(s) (Theorems 5 and 6).
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 1; 75-81
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of transfer functions using estimated rational functions to detect winding mechanical faults in transformers
Autorzy:
Bigdeli, M.
Vakilian, M.
Rahimpour, E.
Powiązania:
https://bibliotekanauki.pl/articles/140596.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
transformator
funkcja przenoszenia
osiowe przesunięcie
funkcja wymierna
transformer
transfer function
fault detection
axial displacement
rational function
Opis:
As it is found in the related published literatures, the transfer function (TF) evaluation method is the most feasible method for detection of winding mechanical faults in transformers. Therefore, investigation of an accurate method for evaluation of the TFs is very important. This paper presents three new indices to compare the transformer TFs and consequently to detect the winding mechanical faults. These indices are based on estimated rational functions. To develop the method, the necessary measurements are carried out on a 1.3 MVA transformer winding, under intact condition, as well as different fault conditions (axial displacement of winding). The obtained results demonstrate the high potential of proposed method in comparison with two other well-known indices. Additionally, two important methods for describing TFs by rational functions are studied and compared in this paper.
Źródło:
Archives of Electrical Engineering; 2012, 61, 1; 85-99
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New pedotransfer function (“CRC”) for the prediction of unsaturated soil hydraulic conductivity using soil water retention data
Autorzy:
Bohne, K.
Renger, M.
Wessolek, G.
Powiązania:
https://bibliotekanauki.pl/articles/2082651.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
soil texture
hydraulic conductivity
transfer
function
soil water retention
Opis:
Several review articles have emphasized, that a comprehensive set of pedotransfer functions may be applied throughout a wide range of disciplines of Earth system sciences and are of great importance for land surface models. Most pedotransfer functions deducing soil hydraulic data from nonhydraulic soil data such as soil texture and bulk density, yield soil water retention predictions, but do not provide information concerning soil hydraulic conductivity. For this reason, a simple method was developed to estimate soil hydraulic conductivity using soil water retention information. Empirical equations are established to predict soil hydraulic conductivity from soil water retention information. These equations are relatively straightforward and do not require the fitting of nonlinear functions. Predictions of soil hydraulic conductivity using 106 soil samples indicates the reliable performance of the new method. The prediction quality of the new method was estimated from the calibration data set, which produced equivalent results to the Zacharias and Wessolek pedotransfer function, which were even better than the predictions obtained from the original Mualem-van Genuchten model, the Soto fractal model, and the pedotransfer function reported by Weynants and Vereecken. The stochastic structure of the calibration data reflects the presence of important soil structural properties, which are not represented by the soil water retention characteristics.
Źródło:
International Agrophysics; 2019, 33, 4; 503-510
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania modelu fragmentu systemu naczyń krwionośnych
Investigations of a model of the blood vessel part
Autorzy:
Bołtrukiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/154841.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
naczynia krwionośne
właściwości dynamiczne
transmitancja
odpowiedź skokowa
fala uderzeniowa
model fizyczny
blond vessel
dynamic specificity
transfer function
step response
impact wave
physical model
Opis:
Przedstawiona praca dotyczy modelowania właściwości dynamicznych systemu naczyń krwionośnych. W pracy wykorzystuje się uzyskaną eksperymentalnie transmitancję fragmentu systemu naczyń krwionośnych znajdującego się pomiędzy stawem łokciowym i nadgarstkiem. W artykule rozważa się dwa modele podatnej tętnicy, które są badane w aspekcie dopasowania do danych uzyskanych doświadczalnie. Do dalszych prac zostaje wybrany model charakteryzujący się dużym stopniem dopasowania do danych eksperymentalnych, uwzględniający rzeczywiste zachowanie cieczy w odkształconej podatnie tętnicy.
The paper concerns the modeling of dynamic specificity of blood vessel. The simple physical models of blood vessel part were investigated. In the experiments a PPG signal was used. The optoelectronic sensors were installed on a wrist and forearm. After the acquisition, the obtained samples of the PPG signal were identified by the RLS method. As a result of the experiments the transfer function of the investigated blood vessel part was obtained. This transmittance is described with Eq. (4), and its step response is shown in Fig. 2. In the work two physical models are considered. The structures of these models are shown in Figs.1 and 3. The first one uses the phenomenon of suppressed oscillations, while the second one - the phenomenon of impact of the liquid wave. The transfer functions of the models are described by Eqs. (6) and (13), respectively. In the study compatibility between the obtained transfer function and the physical models was verified. The transfer function of blood vessel and the transfer functions of physical models were compared. Their step responses were compared, too. Finally, the correspondence between the second physical model and the transmittance of the blood vessel part was experimentally proved.
Źródło:
Pomiary Automatyka Kontrola; 2012, R. 58, nr 4, 4; 344-347
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Space remote sensing systems transmission capabilities modeling
Autorzy:
Burshtynska, K.
Dolynska, I.
Powiązania:
https://bibliotekanauki.pl/articles/100711.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie
Tematy:
space image
modulation transfer function
resolution
przestrzeń obrazowa
MTF
Opis:
Space information, or information obtained by means of space remote sensing, is widely and effectively used by many countries to solve a lot of scientific, technical and applied problems. Most manufacturers of space remote sensing systems declared the high resolution values of their systems. However, these values are computed theoretically, without considering the various factors affected them. To determine the real resolution of the system, we have considered mathematical modeling which describes the influence of different factors on the satellite images resolution. Some of these factors are: atmosphere turbulence, image shift, residual defocusing, and diffraction. One of the most important characteristic of the images resolution is the modulation transfer function (MTF) which allows the estimation of different factors affected on the image resolution. The modulation transfer function (MTF) is a fundamental tool for assessing the performance of imaging systems. Various authors [Zhang et al. 2012, Hwang et al. 2008, Ryan et al. 2003] investigate diferent MTF assessment methods of high resolution satellite images: a slant-edge method, a knife-edge method, a sine wave method and a grill pattern. We propose a generalized approach for MTF assessment based on theoretical assumptions which allows to determine the inluence of diferent factors. A comparative analysis of the modulation transfer function(s) for different space imaging systems shows that the image resolution depends mainly on the atmosphere turbulence and size of a sensor element. Additionally, we established that atmospheric turbulence significantly reduces the transmitting possibility of images. The parameters which describe the influence of turbu¬lence required additional studies. The main goal of our researches is to show that real spatial image(s) resolution is much "inferior" than the value provided by the manufacturers of space remote sensing systems.
Źródło:
Geomatics, Landmanagement and Landscape; 2013, 3; 27-35
2300-1496
Pojawia się w:
Geomatics, Landmanagement and Landscape
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of parameter constraints in EE and OE methods for optimal identification of continuous LTI models
Autorzy:
Byrski, W.
Byrski, J.
Powiązania:
https://bibliotekanauki.pl/articles/331405.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system ciągły
funkcja przenoszenia
metoda najmniejszych kwadratów
continuous systems
parameter constraints in identification
modulating functions
transfer function normalization
least squares method
Opis:
The paper presents two methods used for the identification of Continuous-time Linear Time Invariant (CLTI) systems. In both methods the idea of using modulating functions and a convolution filter is exploited. It enables the proper transformation of a differential equation to an algebraic equation with the same parameters. Possible different normalizations of the model are strictly connected with different parameter constraints which have to be assumed for the nontrivial solution of the optimal identification problem. Different parameter constraints result in different quality of identification. A thorough discussion on the role of parameter constraints in the optimality of system identification is included. For time continuous systems, the Equation Error Method (EEM) is compared with the continuous version of the Output Error Method (OEM), which appears as a special sub-case of the EEM.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 2; 379-388
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł

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