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Wyszukujesz frazę "Vector" wg kryterium: Temat


Tytuł:
Modeling and optimization of activated carbon carbonization process based on support vector machine
Autorzy:
Liu, Gangyang
Zhang, Chunlong
Dou, Dongyang
Wei, Yinghua
Powiązania:
https://bibliotekanauki.pl/articles/1448262.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
carbonization process
optimization
modeling
support vector machine
Opis:
Product prediction and process parameter optimization in the production process of activated carbon are very important for production. It can stabilize product quality and improve the economic efficiency of enterprises. In this paper, three process parameters of a carbonization furnace, namely feeding rate, rotation speed, and carbonization temperature, were adopted to build a quality optimization model for carbonized materials. First, an orthogonal test was designed to obtain the preliminary relationship between the process parameters and the quality indicators of a carbonized material and prepare data for modeling. Then, an improved SVR model was developed to establish the relationship between product quality indicators and process parameters. Finally, through the singlefactor experiments and the Monte Carlo method, the process parameters affecting the quality of a carbonized material were determined and optimized. This showed that a high-quality carbonized material could be obtained with a smaller feeding rate, larger rotation speed, and higher carbonization furnace temperature. The quality of activated carbon reached its maximum when the feeding rate was 1.0 t/h, the rotation speed was 90 r/h, and the temperature was 836°C. It can effectively improve the quality of carbonized materials.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 2; 131-143
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of circular aperture diffraction on propagation properties of cylindrical vector partially coherent Laguerre–Gaussian beams in turbulent atmosphere
Autorzy:
Peng, Z.
Jia, X.
Powiązania:
https://bibliotekanauki.pl/articles/173537.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cylindrical vector beams
diffraction
aperture
atmospheric propagation
Opis:
On the basis of the extended Huygens–Fresnel integral formula, the analytical formulae for the cross-spectral density matrix of the arbitrary cylindrical vector partially coherent Laguerre–Gaussian beams diffracted by a circular aperture in turbulent atmosphere are derived. The average intensity, the degree of polarization, and the degree of coherence of the apertured cylindrical vector partially coherent beams propagating in turbulent atmosphere are investigated. The analyses indicate that both the beam diffraction effect by a circular aperture and the atmospheric turbulence have a great impact on the beam evolution, polarization and coherence properties of the apertured cylindrical vector partially coherent beams.
Źródło:
Optica Applicata; 2018, 48, 3; 421-433
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of motion peculiarities of particles of the Rayleigh light scattering mechanism for defining the coherence properties of optical fields
Autorzy:
Zenkova, C
Soltys, I
Angelsky, P
Powiązania:
https://bibliotekanauki.pl/articles/173481.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
degree of coherence
nanoparticles
Poynting vector
light scattering
Opis:
The paper proposes an alternative possibility for using the motion dynamics of tested particles of the Rayleigh light-scattering mechanism for estimating the degree of coherence of mutually orthogonal fields. The velocity of nanoparticles motion in the inhomogeneous optical field is chosen as the measuring parameter for diagnostics. The direct connection between the velocity of nanoscale particle motion and the degree of coherence of interacting fields is analytically demonstrated.
Źródło:
Optica Applicata; 2013, 43, 2; s. 297-312
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of electromagnetic filtration efficiency using least squares support vector model
Autorzy:
Yuceer, M.
Yildiz, Z.
Abbasov, T.
Powiązania:
https://bibliotekanauki.pl/articles/110758.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
electromagnetic filtration
disperse systems
support vector machine (SVM)
Opis:
The present study aims to apply a least squares support vector model (LS–SVM) for predicting cleaning efficiency of an electromagnetic filtration process, also called quality factor, in order to remove corrosion particles (rust) of low concentrations from water media. For this purpose, three statistical parameters: correlation coefficient, root mean squared error and mean absolute percentage error were calculated for evaluating the performance of the LS–SVM model. It was found that the developed LS–SVM can be used to predict the effectiveness of electromagnetic filtration process.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 173-180
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Focus shaping of the radially polarized Bessel–Gauss beam with a sine-azimuthal variation wavefront
Autorzy:
Gao, X
Zhang, D.
Mei, T.
Fu, R.
Zhuang, S.
Powiązania:
https://bibliotekanauki.pl/articles/174283.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Bessel-Gauss beam
wavefront modulation
vector diffraction theory
Opis:
Focusing properties of the radially polarized Bessel–Gauss beam with a sine-azimuthal variation wavefront was investigated by the vector diffraction theory. The wavefront distribution is the sine function of the azimuthal angle with one phase parameter that indicates the phase change frequency. Results show that the focal pattern can be altered by the phase parameter, and many novel focal patterns may occur, such as multiple dark-foci focal pattern, crescent shape, and wheel shape. For case of a higher phase beam, the whole focal pattern turns on a symmetric wheel shape with multiple reduplicate intensity elements. When the phase parameter is an odd number, the number of reduplicate elements equals the phase parameter, while when the phase parameter is an even number, the number of reduplicate elements is two times the phase parameter. In addition, the effect of the phase parameter on the focal pattern is more considerable than that of the beam parameter under low numerical aperture. Under higher numerical aperture, the effect of the beam parameter on the focal pattern gets stronger.
Źródło:
Optica Applicata; 2013, 43, 3; 567-582
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Direct Torque Control with Space Vector Modulation for Synchronous Reluctance Motor Motion Control Applications and a Comparison with Other Torque-Control Algorithms
Autorzy:
Vajsz, Tibor
Számel, László
Handler, Árpád
Powiązania:
https://bibliotekanauki.pl/articles/1193683.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
synchronous reluctance motor
electric drive
direct torque control
space vector modulation
frequency converter
motion control
current vector control
industrial drives
Opis:
Motion control is facing an increasing popularity in the present research activities. Owing to the expected wide spreading of motion control applications, it can be predicted that the advancements in the field of electric motor drives will have a high level of influence on the new results in the field of motion control. The synchronous reluctance motor drives mean an excellent and yet cost-effective solution for actuators in motion control applications. In this article, the direct torque control with space vector modulation is analysed as a possible candidate for synchronous reluctance motor motion control applications. Its torque-control performance is investigated as a function of torque-control sample time, and a comparison of the torque ripples is made with other torque-control algorithms by an FFT analysis.
Źródło:
Power Electronics and Drives; 2019, 4, 39; 103-113
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concerning the vector control of a squirrel-cage induction motor
Autorzy:
Firago, B.
Vasilyev, D.
Powiązania:
https://bibliotekanauki.pl/articles/1814042.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
induction motor
synchronous rotating frame
vector control
mathematical model
Opis:
A technique for investigation of electric drive dynamics when an induction motor operates at the direct vector control with alignment of the axis x of synchronous rotating frame x–y along the rotor flux linkage vector is presented here. Simulation results of the specific electric drive verify the faithfulness of recommended technique.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2014, 70, 34; 271--285
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Position tracking systems for AC drives employing forced dynamics control
Autorzy:
Vittek, J.
Gorel, L.
Vavrus, V.
Struharnansky, L.
Powiązania:
https://bibliotekanauki.pl/articles/1193302.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
position control
AC drives
vector control
forced dynamics control
observer
Opis:
Position tracking systems for AC drives offering high robustness to external load torques have been presented. A triple-loop cascade control structure was employed where the inner loop is a stator current control loop and the middle loop is a speed control loop based on the forced dynamic control and respecting vector control principles. Two alternative outer position control loop designs both of which respect prescribed dynamics and settling time of position have been developed. The former system prescribes also time constant of the speed control loop while the latter one respects time constant of speed control system developed independently. To enhance the tracking abilities of both control systems the dynamic lag pre-compensator has been included. Case studies of the both position control systems for time near-optimal control and energy near-optimal control have been presented. The tracking performances of the designed control systems were assessed based on comparisons of the experimental responses with the simulated responses of the ideal closed-loop system.
Źródło:
Power Electronics and Drives; 2017, 2, 37/1; 89-103
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of the speed sensorless induction motor drive with magnetizing reactance estymator
Analiza właściwości bezczujnikowego napędu indukcyjnego z estymatorem reaktancji magnesującej
Autorzy:
Dybkowski, M.
Orłowska-Kowalska, T.
Tarchała, G.
Powiązania:
https://bibliotekanauki.pl/articles/1807699.pdf
Data publikacji:
2011
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
variable speed drives
induction motor
vector control
sensorless control
estimators
Opis:
W artykule przedstawiono wyniki badań bezczujnikowego napędu indukcyjnego z prądowym estymatorem prędkości i strumienia wirnika. Napęd bezczujnikowy został wyposażony w dodatkowy estymator reaktancji magnesującej, wykorzystujący matematyczną interpolację charakterystyki magnesowania silnika. Przeanalizowano właściwości dynamiczne takiego układu napędowego ze sterowaniem wektorowym w szerokim zakresie zmian prędkości zadanej. Przedstawiono wyniki badań symulacyjnych i eksperymentalnych.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2011, 65, 31; 147-158
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of reducing switching losses in three-level NPC inverter
Autorzy:
Beniak, R.
Rogowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1193262.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
reduction of switching losses
three-level NPC inverter
space vector modulation
Opis:
The aim of the paper is to present a concept of implementation of a space vector modulation (SVM) algorithm, which is used to create alternating current waveforms of changing amplitude and frequency in power inverters. The main goal of the method is to decrease the number of state changes in power transistors. It is realized by utilizing a prediction algorithm and sequences of transistors, which are not common in use. The method requires measurement of inverter output current flow. The prediction algorithm analyzes possible sequences of transistors’ states and choose those which offers smaller switch count. A decrease of about 20% was obtained for the cases tested. This paper presents simulation result for selected driving scenario. The described method decreases the number of state changes in power transistors and therefore it is a potentially good method to considerably decrease energy losses of multilevel inverter-powered drive.
Źródło:
Power Electronics and Drives; 2016, 1, 36/2; 55-63
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of reducing switch count in three-level NPC inverter – analysis in steady states
Autorzy:
Beniak, R.
Rogowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1193464.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
reduction of switch count
three-level NPC inverter
space vector modulation
Opis:
The proof of a concept for a new method of modulation has been presented which reduce switch count in a three-level neutral point clamped (3L-NPC) inverter. The method is an implementation of space vector modulation (SVM) by means of a prediction algorithm and sequences of transistors, which are not common in use. Those sequences make active use of clamping diodes of the inverter. The prediction algorithm analyzes possible sequences of transistors’ states and choose those which offers smaller switch count. Measurements of steady states were taken on prototype 3L-NPC.
Źródło:
Power Electronics and Drives; 2017, 2, 37/2; 117-126
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission stability of chirped dark vector quasi-solitons in birefringent fiber system with nonlinear gain
Autorzy:
Xiao, Yan
Zhang, Jing
He, Qi
Powiązania:
https://bibliotekanauki.pl/articles/1835764.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chirped dark vector quasi-soliton
coupled Ginzburg-Landau equation
birefringent fiber
Opis:
In this article, we consider the coupled Ginzburg–Landau equation with variable coefficients including the nonlinear gain and obtain the exact solutions of chirped dark vector quasi-solitons via the ansatz method. Next, the propagation of chirped dark vector quasi-solitons is discussed to verify whether they can be transmitted stably in the birefringent optical fiber system. The numerical simulation shows that this can be achieved. We deeply add the small perturbation to the transmission of dark vector quasi-solitons to make the results above more general. The results further prove the correctness of our solutions.
Źródło:
Optica Applicata; 2021, 51, 1; 51-58
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast near-infrared palmprint recognition using nonnegative matrix factorization extreme learning machine
Autorzy:
Xu, X.
Zhang, X.
Lu, L.
Deng, W.
Zuo, K
Powiązania:
https://bibliotekanauki.pl/articles/173572.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
extreme learning machine
palmprint recognition
superior speed
support vector machine (SVM)
Opis:
Support vector machine and artificial neural network are widely used in classification applications. Extreme learning machine (ELM) is a novel and efficient learning algorithm based on the generalized single hidden layer feed forward networks, which performs well in classification applications. The research results have shown the superiority of ELM with the existing classical algorithms: support vector machine (SVM) and back propagation neural network. In this study, we firstly propose a novel nonnegative matrix factorization extreme learning machine (NMFELM) to improve the performance of standard ELM method. Then we propose a novel near-infrared palmprint recognition approach based on NMFELM classifier. As the test data, we use the near-infrared palmprint database provided by Hong Kong Polytechnic University. The experimental results demonstrate that the proposed NMFELM method outperforms the standard ELM- and SVM-based methods.
Źródło:
Optica Applicata; 2014, 44, 2; 285-298
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved algorithm for feature extraction from a fingerprint fuzzy image
Autorzy:
Surmacz, K.
Saeed, K.
Rapta, P.
Powiązania:
https://bibliotekanauki.pl/articles/174451.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
biometrics
feature extraction
fingerprints
minutiae
Gabor filter
feature vector
image processing
Opis:
Proper fingerprint feature extraction is crucial in fingerprint-matching algorithms. For good results, different pieces of information about a fingerprint image, such as ridge orientation and frequency, must be considered. It is often necessary to improve the quality of a fingerprint image in order for the feature extraction process to work correctly. In this paper we present a complete (fully implemented) improved algorithm for fingerprint feature extraction, based on numerous papers on this topic. The paper describes a fingerprint recognition system consisting of image preprocessing, filtration, feature extraction and matching for recognition. The image preprocessing includes normalization based on mean value and variation. The orientation field is extracted and Gabor filter is used to prepare the fingerprint image for further processing. For singular point detection, the Poincaré index with a partitioning method is used. The ridgeline thinning is presented and so is the minutia extraction by CN algorithm. The paper contains the comparison of obtained results to the other algorithms.
Źródło:
Optica Applicata; 2013, 43, 3; 515-527
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Focus shaping of Weierstrass solid immersion lens by an axisymmetric Bessel-modulated Gaussian beam
Autorzy:
Dong, X
Geng, T
Zhuang, S
Powiązania:
https://bibliotekanauki.pl/articles/174767.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Weierstrass solid immersion lens
Bessel-modulated Gaussian beam
vector diffraction theory
Opis:
Weierstrass solid immersion lens (SIL) has been used to obtain superresolution because a smaller focal size is desirable. In this paper, focus shaping of Weierstrass SIL illuminated by an axisymmetric Bessel-modulated Gaussian beam (QBG beam) is investigated. It has been found theoretically that the sharper focusing of Weierstrass SIL disappears for a certain beam order of QBG beam. For case of a smaller beam order, the focus still locates on the plane of Weierstrass SIL and Weierstrass SIL still plays a tighter focusing role. However, when the beam order increases continuously, the focus lefts the plane of Weierstrass SIL, and shifts along an optical axis considerably. In addition, under condition of the higher beam order, the dependence of the focal shift on the beam order is nearly linear, which may be used to alter a focal position conveniently.
Źródło:
Optica Applicata; 2013, 43, 2; s. 247-259
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł

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