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Wyszukujesz frazę "filter" wg kryterium: Temat


Tytuł:
Investigation of a selectable multi-passband microwave photonic filter based on cascaded optical comb filters
Autorzy:
Wang, F.
Peng, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/2033940.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microwave photonic filter
multi-passband filter
microwave signal processing
Opis:
A multi-passband microwave photonic filter (MPF) with selectable passband frequency, spanning 0-20 GHz frequency range, is proposed, and experimentally demonstrated, in which passband frequency can be flexibly selected within a maximum passband number to four. The scheme is based on the generation of tunable optical comb lines using a broadband optical source sliced by cascaded optical comb filters, achieved by connecting an in-line birefringence fiber filter and a reconfigurable Lyot filter in series, such that various filter tap spacing and spectral combinations are obtained for the configuration of the MPF. The proposed MPF can operate with four different passband states, namely, single-, dual-, triple-, and quadruple-passband, only by adjusting polarization states of the cascaded optical comb filters. All these passbands are with a 3-dB bandwidth varying from 200 to 460 MHz and more than 20-dB sidelobe suppression.
Źródło:
Optica Applicata; 2021, 51, 3; 457-467
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Introduction to the Special Section on State and Parameter Estimation Methods for Sensorless Drives
Autorzy:
Barut, M.
Hinkkanen, M.
Orlowska-Kowalska, T.
Powiązania:
https://bibliotekanauki.pl/articles/1193677.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sensorless control
extended Kalman filter
unscented Kalman filter
MRAS estimators
neural networks
Opis:
This short article constitutes an introductory part of the Special Section (SS) on State and Parameter Estimation Methods in Sensorless Drives. In the current issue of the journal, the first part of this section is published. Accepted articles are focussed mainly on estimation of the state variables and parameters for vector-controlled induction motor (IM) drives, using different concepts, such as different types of Kalman filters (KFs) and model reference adaptive systems (MRASs). The KF was also proposed for brushless DC motor (BLDC). Also, neural networks (NNs) have been proposed for mechanical state variables’ estimation of the drive system with elastic couplings.
Źródło:
Power Electronics and Drives; 2018, 3, 38; 111-113
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the symmetrical deformation y = xk + 1 on the optimization of the symmetrical multiple channeled white light color filter
Autorzy:
Baraket, Z.
Zaghdoudi, J.
Kanzari, M.
Powiązania:
https://bibliotekanauki.pl/articles/173545.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystals
symmetry
filter
polarization
optimization
Opis:
In this paper, we consider a hybrid photonic crystal symmetrically deformed (Bg5/Cu3/Bg5) consisting of the third generation of the copper mean sequence (Cu3), sandwiched between two Bragg mirrors at the fifth generation (Bg5). Our system realizes a polychromatic filter that transmits five wavelengths in the visible spectrum independently of the polarization of the light transverse electric or transverse magnetic. Secondly, the photonic crystal (Bg5/Cu3/Bg5) undergoes the deformation y = xk + 1 (where k is the degree of deformation, x and y are respectively the coordinates of the system before and after the deformation). With a proper choice of the degree of deformation k, this photonic crystal maintains its property of polychromatic filter whose transmission wavelength is independent of the polarization’s state. Thanks to this deformation, we can disperse the optical windows in different spectra of visible light and exactly in the violet, blue, green, and orange light. This system can be used in the fabrication of color filter devices and the white light emitting diodes.
Źródło:
Optica Applicata; 2017, 47, 1; 19-28
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of photonic crystal filter based on slack variables
Autorzy:
Yang, H.
Peng, S.
Meng, S.
Powiązania:
https://bibliotekanauki.pl/articles/173949.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal filter
slack variables
optimization
Opis:
The improved model based on slack variables is designed to optimize a photonic crystal filter. An optimization model of the filter is established, with the transmission quantity in a stop-band as the objective function and the transmission quantity outside a stop-band as the constraint condition. The improved model is obtained by introducing slack variables in the infeasible region. With the treatment of objective and constraint functions, the optimization problem and the improved model are solved by sequential linear programming. Then the convergent solution satisfying the constraints can be found. The change of the objective function and design variables with iteration steps is presented by numerical examples, and the influence of by the constraints on the central frequency of the stop-band is discussed, indicating that the improved model is available and effective for optimization of a photonic crystal filter.
Źródło:
Optica Applicata; 2017, 47, 4; 621-633
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission characteristics of 85Rb and 87Rb laser-induced dichroism atomic filters at 795 nm
Autorzy:
Peng, Y F
Zhang, W J
Powiązania:
https://bibliotekanauki.pl/articles/173843.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
atomic filter
optical anisotropy
narrowband
rubidium
Opis:
The transmission characteristics for 85Rb and 87Rb laser-induced dichroism atomic filters operating on rubidium D1 lines (795 nm) transitions are analyzed. By means of semiclassical density matrix equations of motion, a three-level model for the transmission characteristics of the ground state laser-induced dichroism atomic filter is presented. Calculative results show that this filter, using two counterpropagating pump and probe beams, can obtain higher transmission, narrower bandwidth and larger tuning capability than that using two copropagating pump and probe beams; with the aid of counterpropagating pump, the 85Rb ground state laser-induced dichroism atomic filter can be more effective to achieve higher peak transmission (>34%) and larger tunability (>1 GHz) than the 87Rb ground state laser-induced dichroism atomic filter in the same operation parameters. This result may be helpful for improving peak transmission (14.6%) of Rb ground state laser-induced dichroism atomic filter reported (CERÈ A. et al., Opt. Lett. 34(7), 2009, pp. 1012–1014).
Źródło:
Optica Applicata; 2014, 44, 1; 55-67
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of packing media on stratified EPS and their role in the biofilm of trickling biofilter
Autorzy:
Dong, Bei
Zheng, Jie
Wen, Yi-Zheng
Lei, Xian-Yan
Zhang, Qian
Cao, De-Ju
Powiązania:
https://bibliotekanauki.pl/articles/2032860.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
EPS
spectroscopy
wastewater treatment
biological filter
ceramsite filter
humic
spektroskopia
oczyszczanie ścieków
filtr biologiczny
filtr keramzytowy
humus
Opis:
The research focused on such packing media as ceramsite, polypropylene balls, and elastic fillers, and analyzed the main characteristics of extracellular polymeric substances (EPS) in their filter biofilms. The EPS were categorized as soluble EPS (S-EPS) and bound EPS (B-EPS). The component characteristics of stratified EPS were investigated via UV-Vis spectroscopy and a three-dimensional excitation-emission matrix (3D-EEM). The results showed that the EPS content of ceramsite biofilm was 245.2 mg/g VSS, which was higher than those of elastic filler material and polypropylene ball by 1.26 and 1.51 times, respectively. The protein (PN) and polysaccharide (PS) ratio of EPS in the ceramsite filter material was highest in S-EPS and B-EPS, indicating that the EPS have a stable structure. More than 67.58% of EPS formed by ceramsite was tightly bound EPS (TB-EPS), which was beneficial to maintaining the stability of biofilms. The levels of proteins (PN) and humic substances formed by ceramsite contained in the TB-EPS were higher than those of elastic filter material and polypropylene balls. 3D-EEM fluorescence spectra revealed that TB-EPS formed by a ceramsite contained high concentrations of tryptophan, tyrosine, and humic substances. The dehydrogenase activity of biofilm formed by ceramsite filler was higher than that formed by elastic fillers and polypropylene balls.
Źródło:
Environment Protection Engineering; 2021, 47, 3; 25-36
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The optimization of the dielectric layer photonic crystal filter by the quadratic response surface methodology
Autorzy:
Yang, H.
Meng, S
Wang, G.
Huang, C.
Powiązania:
https://bibliotekanauki.pl/articles/174592.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optimization
photonic crystal filter
response surface methodology
Opis:
Dielectric layer photonic crystal filter structures in waveguide are optimized by the quadratic response surface methodology. The optimization model of the filter is established on the basis of the analysis which is conducted with the aid of the response surface methodology. The model is solved using sequential quadratic programming and the optimal parameters are obtained. Examples demonstrate it is effective.
Źródło:
Optica Applicata; 2015, 45, 3; 369-379
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of on-line froth depth measurement errors in industrial flotation columns: a promising tool for automatic control
Autorzy:
Nakhaei, F.
Irannajad, M.
Powiązania:
https://bibliotekanauki.pl/articles/110715.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
prediction
accuracy
froth height
Kalman filter
error
Opis:
The pulp-froth interface position is important from a metallurgical point of view because it determines the relative importance of the cleaning and the collection zones. The pulp-froth interface position is measured based on variations of specific gravity, temperature or conductivity between the two zones to locate the pulp froth interface position. In this study, the pressure measurements are used to calculate the values of the froth layer height. These two meters are installed in the upper part of the column at 1.4 m and 2.4 m respectively, from the top of the column. Methods using pressure gauges are commonly used in industrial operations Even though their accuracy is limited (due to assumptions of uniformity of the pulp and froth density), and they always have some error. In the Sarcheshmeh copper industrial plant (Iran), a float was installed near the column with 2.5 m height that was calibrated to 5 cm intervals in order to determine the more exact forth height and compare it with the recorded froth height in control room. In this paper, an algorithm based on Kalman Filter is presented to predict on-line froth height errors using two pressure gauges. This research is based on the industrial real data collection for evaluating the performance of the presented algorithm. The quality of the obtained results was very satisfied. The RMS errors of prediction froth height errors was less than 0.025 m.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 757-768
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Channel drop filter based on photonic crystal ring resonator
Autorzy:
Alipour-Banaei, H.
Jahanara, M.
Mehdizadeh, F.
Powiązania:
https://bibliotekanauki.pl/articles/174022.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal
optical filter
ring resonator
quality factor
Opis:
Photonic crystal ring resonators are promising candidates for realizing all optical filters with acceptable transmission efficiency and quality factor values. In this paper, by putting a hexagon-shaped structure at the middle of on 7 × 7 square cavity we created a ring resonator structure and designed a channel drop filter. The drop wavelength of our filter is at 1550.4 nm, with transmission efficiency and quality factor equal to 94% and 707, respectively. Our structure is composed of dielectric rods immersed in air. Because in this kind of structures the dominant band gap is in TM mode, all of our simulations have been done in TM mode. The total footprint of our filter is 199.4 μm2, which makes it suitable for all optical integrated circuits.
Źródło:
Optica Applicata; 2018, 48, 4; 601-608
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization dependence of stimulated Brillouin scattering-based switchable microwave photonic filter
Autorzy:
Gu, Jun
Wang, Fei
Lu, Youxi
Peng, Mengmeng
Shi, Lun
Kang, Wen
Huang, Jingxin
Powiązania:
https://bibliotekanauki.pl/articles/173837.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microwave photonic filter
stimulated Brillouin scattering
polarization dependence
Opis:
We propose and experimentally demonstrate a switchable microwave photonic filter based on polarization dependence of stimulated Brillouin scattering (SBS). The continuous optical wave from a tunable laser source is split into two branches. One branch serves as the SBS pump source and another branch serves as the signal source which are interactional to generate the SBS effect in the dispersion-shifted fiber. Only by adjusting the polarization direction of pump light and signal light, a frequency response switched between bandpass and notch filtering shape can be obtained.
Źródło:
Optica Applicata; 2019, 49, 1; 5-11
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of thermal tunable multichannel filter using defective metallic photonic crystals
Autorzy:
Gharaati, A.
Zare, Z.
Powiązania:
https://bibliotekanauki.pl/articles/174165.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystals
temperature dependent refractive index
multichannel filter
defective mode
Opis:
The transmission spectra of one dimensional metallic photonic crystal containing defects are studied using a transfer matrix method. We consider silver as a defect layer with a refractive index dependent on wavelength and temperature simultaneously. Since the loss factor of silver is the function of temperature, we should find a structure that has sharp transmission peaks to model a filter. We present the structure with a coupled defect. It is found that the number of transmission resonant peaks is equal to the number of coupled defects and they are tunable with temperature and incident angle.
Źródło:
Optica Applicata; 2017, 47, 4; 611-619
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-objective optimization of dielectric layer photonic crystal filter
Autorzy:
Yang, H.
Huang, C.
Meng, S.
Powiązania:
https://bibliotekanauki.pl/articles/174482.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
filter
photonic crystal
weighting factors method
response surface methodology
RSM
Opis:
The weighting factors method and the response surface methodology are used to achieve multi-objective optimization of a dielectric layer photonic crystal filter. The size of period and the transmission quantity are considered simultaneously and a multi-objective optimization model of filter is established, which takes the size of period and transmission quantity to be minimized in stop-band as objectives. Global approximate expressions of the objective and the constraint functions are found by response surface methodology. Then the weighting factors method is employed to convert the model into a quadratic programming model and the optimal parameters can be obtained using sequence quadratic programming. Examples provide the optimized results in three different weight coefficients. The effect of the weighting factors on the value of the objective function is also discussed. Results show that the present method is precise and efficient for multi-objective optimization of a dielectric layer photonic crystal filter.
Źródło:
Optica Applicata; 2017, 47, 1; 29-40
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Damping in Series Connected Power Modules with Continuous Output Voltage
Autorzy:
Ulmer, Sabrina
Schullerus, Gernot
Sönmez, Ertugrul
Powiązania:
https://bibliotekanauki.pl/articles/1955969.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
power electronics
modularity
scalability
GaN
gallium nitride
active filter damping
Opis:
This paper presents a modular and scalable power electronics concept for motor control with continuous output voltage. In contrast to multilevel concepts, modules with continuous output voltage are connected in series. The continuous output voltage of each module is obtained by using gallium nitride (GaN) high electron motility transistor (HEMT)s as switches inside the modules with a switching frequency in the range between 500 kHz and 1 MHz. Due to this high switching frequency a LC filter is integrated into the module resulting in a continuous output voltage. A main topic of the paper is the active damping of this LC output filter for each module and the analysis of the series connection of the damping behaviour. The results are illustrated with simulations and measurements.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 314-335
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization Of Current Magnitude Estimators Based On Marquardt-Levenberg Algorithm
Autorzy:
Łukowicz, M.
Solak, K.
Wicher, P.
Wiecha, B.
Powiązania:
https://bibliotekanauki.pl/articles/410595.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
signal processing
digital filter
magnitude estimator
high speed overcurrent relay
Opis:
Digital filtering, correlation methods, time delay methods, signal differentiation are the most commonly used methods of estimating fundamental frequency orthogonal components utilized in magnitude estimators. The foundation for designing filters used in aforementioned methods are usually demanded frequency responses or signal models with their parameters to be estimated. A weak point of both approaches is frequency-domain modelling ignoring time-domain performance of the magnitude estimators. In order to fulfil the requirements of protection with the optimum speed for many different configurations, operating conditions and construction features of power systems, it is necessaiy to develop magnitude estimator design methods aimed at modelling with respect to highspeed response with simultaneous acceptable estimation accuracy in the steady state. The article discusses the implementation of Levenberg-Marquardt algorithm to optimization of current magnitude estimators designed for power system protection with the focus on estimators used in instantaneous overcurrent relays. The paper presents details of optimizing algorithm, power system model used for acquisition of signal patterns and estimator performance analyzes.
Źródło:
Present Problems of Power System Control; 2016, 7; 5-17
2084-2201
Pojawia się w:
Present Problems of Power System Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on heavy metals mobility from zinc plant residues in Iran
Autorzy:
Moradkhani, D.
Eskandari, S.
Sedaghat, B.
Najafabadi, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/110826.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
heavy metals
zinc leaching plant
leaching filter cake
column leaching
Opis:
The transport of heavy metals from mining disposal site to groundwater and surface water is one of the most serious environmental problems in the world. The transport of heavy metals such as Zn, Cd and Mn from leaching filter cake in RECo, Zanjan, Iran was examined by using column leaching. Parameters studied included: flow rate, pH of input solution and leaching time. In this study, the maximum dissolution percents of Zn, Cd and Mn in input solution pH of 5 were 45.50 %, 53.97% and 19.94%, respectively. To statistically analysis the experimental results, SPSS14 software was employed. The results of SPSS 14 indicated that for the Zn, Cd and Mn dissolution, time and flow rate were found respectively, the effective parameters for the pollution in zinc leach residues.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 567-574
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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