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Tytuł:
Recent advances in mode converters for a mode division multiplex transmission system
Autorzy:
Memon, A. K.
Chen, K. X.
Powiązania:
https://bibliotekanauki.pl/articles/1818205.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
integrated optical device
mode converters
mode division multiplex
optical waveguide
Opis:
Adopting mode division multiplex (MDM) technology as the next frontier for optical fiber communication and on-chip optical interconnection systems is becoming very promising because of those remarkable experimental results based on MDM technology to enhance capacity of optical transmission and, hence, making MDM technology an attractive research field. Consequently, in recent years the large number of new optical devices used to control modes, for example, mode converters, mode filters, mode (de)multiplexers, and mode-selective switches, have been developed for MDM applications. This paper presents a review on the recent advances on mode converters, a key component usually used to convert a fundamental mode into a selected high-order mode, and vice versa, at the transmitting and receiving ends in the MDM transmission system. This review focuses on the mode converters based on planar light wave circuit (PLC) technology and various PLC-based mode converters applied to the above two systems and realized with different materials, structures, and technologies. The basic principles and performances of these mode converters are summarized.
Źródło:
Opto-Electronics Review; 2021, 29, 1; 13--32
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Helically twisted long-period fiber gratings of YOFC single-mode fiber with optical fiber welding machine
Autorzy:
Bai, Yunfeng
He, Zelong
Bai, Jiyuan
Dang, Suihu
Powiązania:
https://bibliotekanauki.pl/articles/2033950.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
YOFC single-mode fiber
helically twisted long-period fiber grating
fundamental mode
cladding mode
coupled mode theory
Opis:
The single-mode fiber provided by YOFC inc is employed for spiral processing by commercial welding machine. It can clearly see the periods structure under the light, but there is no obvious deformation of the fiber core, cladding and surface morphology under a microscope. There is an obvious resonant peak near 1560 nm, half peak width is about 25 nm, the depth of the resonant peak closed to –26 dB, when the period is about 411 μm. It agrees with theoretical calculation results according to the long-period fiber grating coupled-mode theory. The resonance wavelength is caused by coupling between the fundamental mode and the LP14 mode. The responsivities of the helically twisted long-period fiber gratings (H-LPFG) for the temperature is measured, the resonance wavelength is linear with temperature, the slope is 86 pm/°C. Because it is easy to inscribe by commercial welding machine, and has a strong resonance peak, it has potential applications as the temperature sensor.
Źródło:
Optica Applicata; 2021, 51, 3; 407-413
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differential and Common Mode Noise Waves and Correlation Matrices
Autorzy:
Dobrowolski, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/226394.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
differential and common mode noise waves
mixed-mode noise wave correlation matrices
generalized multiport mixed-mode noise wave correlation matrice
Opis:
This paper presents an innovative extention of the noise wave definition to mixed mode, differential – and common-mode noise waves which can be used for noise analysis of differential microwave networks. Mixed mode noise waves are used next to define generalized mixed mode noise wave correlation matrices of microwave multiport networks. Presented approach may be used for noise analysis of microwave differential networks with differential ports as well as with conventional single ended ports.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 2; 133-141
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mixed Mode Survey Design: problem efektu techniki
Mixed Mode Survey Design: Mode Effect Problem
Autorzy:
Sztabiński, Franciszek
Żmijewska-Jędrzejczyk, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/412876.pdf
Data publikacji:
2012
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
Total Survey Error
błąd braku odpowiedzi
efekt techniki
Mixed Mode Survey Design
Europejski Sondaż Społeczny
Non-Response Error
Mode Effect
European Social Survey
Opis:
W sytuacji pogarszających się warunków realizacji badań surveyowych poszukuje się sposobów ograniczenia błędu pomiaru (Total Survey Error), związanego z nieuczestniczeniem wylosowanych jednostek w wywiadzie (Non Response Error). Jedno z rozwiązań stanowi procedura Mixed Mode Survey Design, która polega na uzyskiwaniu tych samych informacji od różnych osób, przy wykorzystaniu odmiennych technik badawczych, np. wywiad PAPI (Paper and Pencil Interviewing), CATI (Computer Assisted Telephone Interviewing), CAWI (Computer Assisted Web Interviewing). Jednakże wykorzystanie tej procedury może powodować wystąpienie efektu techniki (tzw. Mode Effects). W artykule analizujemy efekt techniki na płaszczyźnie: (i) sformułowania pytania; (ii) sposobu kontaktowania oraz (iii) sposobu komunikowania się z respondentem, poddając ocenie wskaźnik realizacji (tzw. Response Rate) oraz porównując odpowiedzi respondentów na te same pytania, uzyskane przy zastosowaniu różnych technik. W analizach wykorzystano materiały zebrane w projektach realizowanych techniką PAPI (badanie European Social Survey, round 3) oraz CATI (badanie w ramach metodologicznego grantu ESS Infrastructure: i3.). Wyniki przeprowadzonych analiz potwierdzają istnienie poważnych różnic związanych z efektem techniki (w przypadku wywiadu PAPI i CATI). Stawia to pod znakiem zapytania ideę ich łączenia celem ograniczenia błędu braku odpowiedzi.
The fieldwork conditions for surveys becomes progressively worse so methods are being sought to reduce the total survey error arising from non-response error. One solution is the mixed mode survey design procedure whereby the same information is obtained from different respondents, using different data collecting modes (e.g. PAPI, CATI, Web survey). However, this procedure may produce the so-called mode effect. In this paper, we analyse the mode effect from the following perspectives: (i) wording of questions, (ii) contacting mode, and (iii) mode of communication with the respondent. We assess response rates and compare respondents’ answers to the same questions obtained through different techniques. Our analysis is based on materials collected in research projects employing two modes PAPI (the European Social Survey, Round 3) and CATI (ESS Infrastructure: i3, a study funded under a methodological grant). The findings from our analysis confirm the existence of significant differences related to the mode effect (in the case of PAPI and CAPI). Those findings challenge the idea of combining those modes to reduce non-response error.
Źródło:
Przegląd Socjologiczny; 2012, 61, 1; 31 - 63
0033-2356
Pojawia się w:
Przegląd Socjologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive fuzzy-sliding mode controller for trajectory tracking control of quad-rotor
Autorzy:
Simoud, Lahcen
Kadri, Boufeldja
Bousserhane, Ismail Khalil
Powiązania:
https://bibliotekanauki.pl/articles/384825.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
quadrotor UAV
sliding mode control
adaptive PD-Slidng mode controller
fuzzy PD-sliding mode
Opis:
This paper deals with the design of an adaptive-fuzzy-PD-Sliding mode controller to achieve stabilization of a quadrotor aircraft in the presence of wind disturbance. Firstly, the dynamic system modeling is carried out using Euler-Lagrange formalism. Then, an adaptive PD-sliding mode control system with an integral-operation switching surface is investigated for quadrotor desired trajectory tracking. Finally, an adaptive fuzzy-PD-sliding mode controller is proposed to achieve control objectives and system stabilization where the fuzzy logic system used to dynamically control parameters settings of the PD-sliding mode equivalent control law. Effectiveness and robustness of the proposed control scheme is verified through simulation results taking into account external disturbances. The simulation results of a quadrotor aircraft control with the proposed controller demonstrate the high performance during flight such as null tracking error and robustness in the presence of external disturbances.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2020, 14, 2; 15-24
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Declarative and Behavioral Data in Predicting Respondents Survey Mode Preference
Autorzy:
Rybak, Adam
Powiązania:
https://bibliotekanauki.pl/articles/1790392.pdf
Data publikacji:
2020-06-24
Wydawca:
Polskie Towarzystwo Socjologiczne
Tematy:
European Social Survey
survey mode preference
mixed-mode survey design
adaptive survey design
Opis:
Using previously established knowledge about survey mode preferences distribution in a population can be one of many ways of improving representativeness and quality of data gathered by survey research. Apart from mode preference existence and stability, the main problem concerns the question: which of the sources of information about mode preference could be treated as trustworthy. Because real observed choices are typically treated as better predictors of future choices than declaration only, this paper tries to answer the question: ‘Are the declarations a good predictor of preference in comparison to real choices?’ For this purpose, it uses combined data from 1) the 2015 Polish mixed-mode ESS experiment and 2) data from ESS8 in Poland. The multinomial logistic regression survey preference model includes socio-demographic variables accompanied by declaration/choice control variable. The results suggest significant differences between choices/declarations. Findings could be used to refine the contact strategies used in surveys.
Źródło:
Polish Sociological Review; 2020, 210, 2; 219-228
1231-1413
2657-4276
Pojawia się w:
Polish Sociological Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding Mode Control of Hybrid Renewable Energy System Operating in Grid Connected and Stand-Alone Mode
Autorzy:
Benadli, Ridha
Bjaoui, Marwen
Khiari, Brahim
Sellami, Anis
Powiązania:
https://bibliotekanauki.pl/articles/1955980.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sliding mode control
grid-connected mode
stand-alone mode
hybrid renewable energy system
wind turbine
photovoltaic
battery energy storage system
maximum power point tracking
Opis:
This paper studies innovative application of sliding mode control (SMC) for a Hybrid Renewable Energy System (HRES) in grid-connected and autonomous modes of operation. The considered HRES includes a photovoltaic (PV), wind turbine (WT) based on a Permanent Magnet Synchronous Generator (PMSG). The PV generator is coupled to the common DC bus via a DC/DC converter. The latter is controlled by an MPPT algorithm based on the Adaptive Perturbation and Observation Algorithm Method (APOAM) to search the optimum working of this source. A SMC is utilized to manage the PV voltage to achieve the Maximum Power Point (MPP) by altering the obligation duty cycle. The battery interfaced by a bidirectional buck-boost DC/DC converter can be charged or discharged depending on the production situation. On the one hand, the wind turbine conversion chain is equipped with a PMSG and a rectifier controlled to regulate the operating point of the wind turbine to its optimum value. During a Stand-Alone Mode (SAM) operation, the Voltage Source Converter (VSC) was used for controlling the output voltage in terms of amplitude and frequency delivered to the AC load. However, in Grid-Connected Mode (GCM) operation, the VSC was adapted to control the electrical parameters of the grid. To better appreciate the advantages of the proposed SMC approach, we have proposed a series of comparative tests with the conventional PI control in the operating modes GC and SA and under different scenarios. The proposed control strategy has undeniable advantages in terms of control performance and very low total harmonic distortion THD value compared with the conventional PI control. Finally, It is concluded that the proposed approach improves the quality and provides a stable operation of the HRES.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 144-166
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of High-Performance Near-threshold Dual Mode Logic Design
Autorzy:
Bikki, Pavankumar
Powiązania:
https://bibliotekanauki.pl/articles/226748.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CMOS logic
dual mode logic
dynamic mode
high performance
minimum energy point
near-threshold
Opis:
A novel dual mode logic (DML) model has a superior energy-performance compare to CMOS logic. The DML model has unique feature that allows switching between both modes of operation as per the real-time system requirements. The DML functions in two dissimilar modes (static and dynamic) of operation with its specific features, to selectively obtain either low-energy or high-performance. The sub-threshold region DML achieves minimum-energy. However, sub-threshold region consequence in performance is enormous. In this paper, the working of DML model in the moderate inversion region has been explored. The near-threshold region holds much of the energy saving of subthreshold designs, along with improved performance. Furthermore, robustness to supply voltage and sensitivity to the process temperature variations are presented. Monte carol analysis shows that the projected near-threshold region has minimum energy along with the moderate performance.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 4; 723-729
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtered integral sliding mode control in a two-mass drive system
Autorzy:
Dróżdż, P.
Szabat, K.
Powiązania:
https://bibliotekanauki.pl/articles/1193310.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
filtered integral sliding mode control
integral sliding mode control
two-mass system
chattering alleviation
Opis:
The paper presents issues related to the application of filtered integral sliding mode control to a two-mass drive system. A classical control structure has been presented and its design procedure is shown in detail. The properties of the classical structure, in which the chattering phenomenon seems to be a big drawback, have been summarized. In order to eliminate this phenomenon, an output low-pass filter has been proposed and the performance of this system has been tested. In order to improve its characteristics, an adaptive low-pass filter has been proposed. The bandwidth of the filter was changed on-line by the fuzzy system according to the current state of the plant. During the steady-states, the bandwidth is low to eliminate chattering effect, and during transients higher in order to ensure the fast dynamics of the plant.
Źródło:
Power Electronics and Drives; 2017, 2, 37/1; 121-134
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
R-Mode receiver development for medium frequency signals
Autorzy:
Grundhöfer, L.
Gewies, S.
Powiązania:
https://bibliotekanauki.pl/articles/134934.pdf
Data publikacji:
2018
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
Global Navigation Satellite Systems
GNSS
GPS
R-mode technology
R-mode receiver
LORAN-C
maritime radio beacons
Opis:
Signals from Global Navigation Satellite Systems are the primary source for Position, Navigation and Time (PNT) information onboard any vessel today. As these signals are prone to interference, a maritime backup system is needed to provide reliable PNT data, R(anging)-Mode is such a system. It utilizes existing maritime radio beacons or base stations of the Automatic Identification System (AIS) by adding ranging components to the legacy signals. The first modified radio beacons transmit medium frequency (MF) R-Mode signals in northern Germany. This paper has described the current state of the authors’ research and development activities at the receiver level for MF R-Mode signals. The receiver platform has been introduced, which was based on off-theshelf components and the implemented algorithms for distance estimation have been explained. Furthermore, the results of the first ranging measurements have been presented, which have shown the general suitability of the R-Mode technology as a source for maritime positioning and timing data.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2018, 56 (128); 57-62
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A window based method to reduce the end-effect in Empirical Mode Decomposition
Autorzy:
Cotogno, M.
Cocconcelli, M.
Rubini, R.
Powiązania:
https://bibliotekanauki.pl/articles/328237.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
empirical mode decomposition
intrinsic mode function
end-effect problem
windowing
Opis:
Empirical Mode Decomposition technique (EMD) is a recent development in non-stationary and non-linear data analysis. It is an algorithm which adaptively decomposes the signal in the sum of Intrinsic Mode Functions (IMFs) from which the instantaneous frequency can be easily computed. EMD has proven its effectiveness but is still affected from various problems. One of these is the “end-effect”, a phenomenon occurring at the start and at the end of the data due to the splines fitting on which the EMD is based. Various techniques have been tried to overcome the end-effect, like different data extension or mirroring procedures at the data boundary. In this paper we made use of the IMFs orthogonality property to apply a symmetrical window to the data before EMD for end-effect reduction. Subsequently the IMFs are post-processed to compensate for data alteration due to windowing. The simulations show that IMFs obtained with this method are of better quality near the data boundaries while remaining almost identical to classical EMD ones.
Źródło:
Diagnostyka; 2013, 14, 1; 3-10
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding mode control for longitudinal aircraft dynamics
Autorzy:
Iskrenovic-Momcilovic, O.
Powiązania:
https://bibliotekanauki.pl/articles/385149.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
aircraft dynamics
control
elevator
longitudinal
sliding mode
Opis:
The control of the longitudinal aircraft dynamics is challenging because the mathematical model of aircraft is highly nonlinear. This paper considers a sliding mode control design based on linearization of the aircraft, with the pitch angle and elevator deflection as the trim variables. The design further exploits the decomposition of the aircraft dynamics into its short-period and phugoid approximations. The discrete-time variable structure system synthesis is performed on the base of the elevator transfer function short-period approximation. This control system contains a sliding mode controller, an observer, based on nominal aircraft model without finite zero and two additional control channels for the aircraft and for the aircraft model. The realised system is stable and robust for parameter and external disturbances.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2018, 12, 3; 55-60
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dylematy związane z estymacją dominanty wynagrodzeń
Dilemmas relating to mode estimation of wages and salaries
Autorzy:
Błażej, Mirosław
Gosińska, Emilia
Powiązania:
https://bibliotekanauki.pl/articles/2156752.pdf
Data publikacji:
2022-12-30
Wydawca:
Główny Urząd Statystyczny
Tematy:
dominanta
estymator jądrowy
estymacja dominanty
histogram
mode
kernel estimator
mode estimation
Opis:
Dominanta wynagrodzeń to ważny wskaźnik opisujący rozkład wynagrodzeń, ale ze względu na silną asymetrię rozkładu tej cechy w Polsce jej wyznaczenie nie należy do standardowych działań w analizie struktury wynagrodzeń. Celem artykułu jest omówienie wybranych metod szacowania dominanty oraz porównanie wyników jej estymacji otrzymanych za pomocą różnych metod. Wykorzystano dane o wynagrodzeniach indywidualnych brutto w październiku 2018 r. pochodzące z badania struktury wynagrodzeń przeprowadzonego przez Główny Urząd Statystyczny. W przypadku metody standardowej, wykorzystującej wzór interpolacyjny i histogram, wartość oszacowanej dominanty jest wrażliwa na założoną rozpiętość przedziałów w szeregu rozdzielczym i początek pierwszego przedziału. Zmniejszanie rozpiętości przedziałów powoduje dążenie dominanty do wartości równej płacy minimalnej. Zastosowanie zaawansowanych metod statystycznych, m.in. wykorzystujących estymator jądrowy, prowadzi do otrzymania znacząco różnych oszacowań dominanty w zależności od metody (rozrzut wyników wynosi ok. 800 zł). Analiza otrzymanych wyników daje ponadto podstawy do rozważenia tezy, że rozkład wynagrodzeń jest mieszany: ma cechy rozkładu dyskretnego dla wynagrodzeń w wysokości płacy minimalnej i ciągłego – dla wynagrodzeń powyżej płacy minimalnej oraz odznacza się cyklicznością (w Polsce zawiera się więcej umów, w których kwota wynagrodzenia jest wielokrotnością 50 zł lub 100 zł, niż umów na inne kwoty).
The mode of wages and salaries is an important indicator describing their distribution; however, due to the strong asymmetry of the distribution of this feature in Poland, mode estimation is not a standard procedure in the analysis of the structure of wages and salaries. The aim of the article is to discuss selected methods of estimating the mode and to compare the mode estimation results obtained by means of various methods. The research is based on data on individual gross wages and salaries registered in October 2018 in Poland. The data came from a survey of the structure of wages and salaries conducted by Statistics Poland. In the case of the standard method based on the interpolation formula and histogram, the mode estimate is sensitive to the assumed span of intervals in the frequency table and the beginning of the first interval. Reducing the span of the intervals causes the mode to reach the value of the minimum wage. The application of advanced methods, including those using a kernel estimator, leads to significantly different estimates of the mode depending on the method used (the dispersion reaches the value of approximately PLN 800). Additionally, the analysis of the obtained results gives grounds to considering a thesis that wage and salary distribution is a mixture of the following distributions: discrete (for the minimum wage) and continuous (for wages and salaries above the minimum wage), and is characterised by cyclicality (in Poland, more contracts offer remunerations which are a multiple of PLN 50 or PLN 100 than remunerations for other amounts).
Źródło:
Wiadomości Statystyczne. The Polish Statistician; 2022, 67, 12; 62-79
0043-518X
Pojawia się w:
Wiadomości Statystyczne. The Polish Statistician
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetostatic analysis of a pinch mode magnetorheological valve
Autorzy:
Gołdasz, J.
Sapiński, B.
Powiązania:
https://bibliotekanauki.pl/articles/386794.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
MR fluid
pinch mode
valve
magnetostatic model
Opis:
The study deals with the pinch mode of magnetorheological (MR) fluids’ operation and its application in MR valves. By applying the principle in MR valves a highly non-uniform magnetic field can be generated in flow channels in such a way to solidify the portion of the material that is the nearest to the flow channel’s walls. This is in contrary to well-known MR flow mode valves. The authors investigate a basic pinch mode valve in several fundamental configurations, and then examine their magnetic circuits through magnetostatic finiteelement (FE) analysis. Flux density contour maps are revealed and basic performance figures calculated and analysed. The FE analysis results yield confidence in that the performance of MR pinch mode devices can be effectively controlled through electromagnetic means.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 3; 229-232
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quasi-Sliding Mode Control of Discrete-Time Systems
Autorzy:
Bartoszewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/908266.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sterowanie
system dyskretny
sliding-mode control
discrete-time systems
Opis:
A reaching law approach to the design of discrete-time quasi-sliding mode control systems is considered. First the required position of the system representative point with reference to the sliding plane is specified, and then novel control strategies, which drive the system in such a way that the position actually changes according to the specification, are proposed. The strategies are linear and consequently the undesirable chattering and high-frequency switching between different values of the control signal are avoided. Furthermore, the state of the controlled system is driven to the narrowest possible band around the sliding plane. The strategies, when compared with previously published results, are simpler and they guarantee favourable performance of the controlled systems while using essentially reduced control effort.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 4; 801-810
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Averaged model of a buck DC–DC converter for single-loop description of current-mode control
Autorzy:
Janke, Włodzimierz
Bączek, Maciej
Kraśniewski, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/141131.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
averaged model
buck converter
continuous conduction mode
peak current
mode control
Opis:
: Averaged models: an AC large signal, DC and AC small signals of a currentcontrolled buck converter are described. Only peak current mode control of a converter working in the continuous conduction mode (CCM) is considered. The model derivation differs from the typical approaches presented in the literature and doesn’t refer to the multiloop concept of a current controlled converter. The separation of the variables method is used in the model derivation. The resulting models are presented in the form of an equation set and equivalent circuits. The calculations based on the presented models are verified by measurements and full-wave PSpice simulations.
Źródło:
Archives of Electrical Engineering; 2019, 68, 4; 891-905
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of a single mode wave generation in cylindrical systems applying numerical methods
Autorzy:
Gorazd, Łukasz
Snakowska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/127909.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
cylindrical duct
multi-mode wave propagation
single mode generation
kanał cylindryczny
wielomodowa propagacja fali
generacja pojedynczego modu
Opis:
The paper presents simulations of a selected single mode generation in systems containing duct-like elements applying the finite element method (FEM). Simulations were carried out for values of the Helmholtz number exceeding the plane-wave propagation, i.e. for a multimode wave. The presented results constitute the first step to analyse propagation of the multimode wave through more complicated systems such as mufflers, even in a form of a cascade. Propagation of the incident wave in the form of a single mode greatly simplifies solutions of many problems, to mention only derivation of the transmission or the scattering matrices. The results obtained can be applied to analyse the effectiveness of attenuation of acoustic silencers or elements of heating, ventilation and air conditioning systems (HVAC) at the design stage. Results of simulations are compared with already published experimental data obtained in a measurement set-up containing the self-designed single mode synthesizer.
Źródło:
Vibrations in Physical Systems; 2019, 30, 1; 1-6
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resonance tests - vibration mode shapes from the wing torsion group
Autorzy:
Wiśniewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/245897.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
aircraft
resonance tests
vibration mode
torsion wing
Opis:
Resonances of the „ wings torsion " mode shapes to a large extent depend on the structural parameters of the wing, and more specifically to the existence or not of fuel tanks at the wings ends, munitions hard points or engines mounted on the wings. In the paper the group of resonances is presented with mode shapes in which the one, two or three node aircraft wing torsion is present. It is shown in the paper, that these vibration mode shapes consist both of fuselage bending or torsion. Resonance frequencies with mode shapes in which one, two or three node wing torsion occurs depend fundamentally on existence of wing hardpoints. If hardpoints are occupied by fuel tanks, these frequencies are varying continuously in wide range. The various interesting from cognitive point of view combinations have place then, including variable frequencies and variable mode shapes as a function of fuel consumption. The aim for the analysis of 3 cases of resonance a wing torsion mode shapes of airplanes and gliders was to investigate the relationships and mechanisms that are taking place and operate between the torsioningl vibration of the wings and bending or torsion vibrations of the fuselage. Recognition of these phenomena should facilitate the researcher to understand and search effectively and explore the resonances of„ wing torsion " mode shapes.
Źródło:
Journal of KONES; 2009, 16, 4; 557-561
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problems of propulsion arrangement choice of multi-mode ship
Autorzy:
Herdzik, J.
Powiązania:
https://bibliotekanauki.pl/articles/246914.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ships propulsion
propulsion arrangement
multi-mode ships
propulsion choice
Opis:
The propulsion system of multi-mode ships cause many problems of proper the choise of propulsion system elements and theirs arrangement in the design process. This system has to fulfil at least two inverse demands. It ought to make possible efficient ship shift (transit mode) from the port to the off shore work place and return to base, to ensure a ship survive at sea in the worst sea condition possible on that sea area and to fulfil conditions of dynamic positioning accuracy (stationkeeping mode) at specified bad state of the sea - not to stop the ship work for long time. The dynamic positioning systems require multi-element ship propulsion application. The fulfilment, all required possibilities and accuracy of ship positioning by chosen propulsion system specified in the project data, is the most important project problem to obtain the minimum investment costs. The redimensioning of propulsion system, increasing the number of thrusters and theirs possibilities gives the benefits in dynamic positioning accuracy, but increases the investment costs. An expensive project may not be realized because of price. The aim of designer is the choice optimum solution of propulsion system, which is fulfils all expectations of ship owner and crew, and performs all project assumptions.
Źródło:
Journal of KONES; 2010, 17, 2; 129-135
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Localized plasma polarimetry based on the phenomenon of normal mode conversion
Autorzy:
Kravtsov, , Y. A.
Bieg, B.
Powiązania:
https://bibliotekanauki.pl/articles/146670.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma
polarimetry
mode conversion
Opis:
A new geometry of microwave polarimetric measurements is presented, which realizes a localized plasma polarimetry based on the phenomenon of electromagnetic mode conversion. Such a conversion takes place in the tokamak plasma, in the vicinity of the point where the microwave beam is orthogonal to one of the helical magnetic lines. In distinction to the traditional plasma polarimetry, which deals with the line averaged plasma parameters, the new methodology allows for a measurement of the local values of plasma parameters near the point of orthogonality. This methodology was shown to be very efficient in studies of the solar radio emission and polarization properties of radio waves passing through the Earth ionosphere. In the following the theory of electromagnetic mode conversion is described and conditions of its applicability are analyzed. It is shown that localized polarimetric measurements of plasma parameters in the geometry of the international thermonuclear experimental reactor (ITER) device would require very high electron densities Ne, exceeding 1017 cm–3, i.e. thousand times higher than those envisaged in the ITER project.
Źródło:
Nukleonika; 2011, 56, 2; 171-174
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy of intrinsic mode function for gas-liquid flow pattern identification
Autorzy:
Sun, Z.
Gong, H.
Powiązania:
https://bibliotekanauki.pl/articles/221137.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas-liquid flow pattern
flow-pattern map
pressure fluctuation
bluff body
signal energy
intrinsic mode function
empirical mode decomposition
Opis:
Gas-liquid flows abound in a great variety of industrial processes. Correct recognition of the regimes of a gas-liquid flow is one of the most formidable challenges in multiphase flow measurement. Here we put forward a novel approach to the classification of gas-liquid flow patterns. In this method a flow-pattern map is constructed based on the average energy of intrinsic mode function and the volumetric void fraction of gas-liquid mixture. The intrinsic mode function is extracted from the pressure fluctuation across a bluff body using the empirical mode decomposition technique. Experiments adopting air and water as the working fluids are conducted in the bubble, plug, slug, and annular flow patterns at ambient temperature and atmospheric pressure. Verification tests indicate that the identification rate of the flow-pattern map developed exceeds 90%. This approach is appropriate for the gas-liquid flow pattern identification in practical applications.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 759-766
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature dependence of polarization mode dispersion in tight-buffered optical fibers
Autorzy:
Borzycki, K.
Powiązania:
https://bibliotekanauki.pl/articles/308525.pdf
Data publikacji:
2008
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
single mode optical fiber
polarization mode dispersion
birefringence
environmental testing
tight buffered fiber
optical fiber cable
optical ground wire
temperature cycling
polymer
Opis:
Experiments and theoretical analysis of influence of temperature on polarization mode dispersion (PMD) in single mode optical fibers and cables are presented. Forces generated by contracting buffer create optical birefringence and increase fiber PMD at low temperatures. Single mode fiber (SMF) in 0.9 mm polymeric tight-buffer can exhibit an extra component of PMD exceeding 0.3 ps/?km in such conditions. On the other hand, tight-buffered spun nonzero dispersion-shifted fibers (NZDSF) and optical units with stranded single mode fibers have showed good stability of PMD over wide range of temperatures. This is due to presence of circular strain in the core, blocking accumulation of mechanically induced birefringence.
Źródło:
Journal of Telecommunications and Information Technology; 2008, 1; 56-66
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Progress in theoretical models of the ICRF mode conversion
Autorzy:
Kazakov, Y. O.
Powiązania:
https://bibliotekanauki.pl/articles/147690.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
ICRF heating
ion-ion hybrid resonance
mode conversion
tokamak
Opis:
The technique of heating the plasma with the electromagnetic waves in the ion cyclotron range of frequencies (ICRF) has many important applications that may lead to improved performance of tokamaks. Recently the heating efficiency of the ICRF mode conversion scenarios characterized by a narrow power deposition profiles received much attention. This paper highlights progress in the theoretical models of the ICRF mode conversion that allowed to achieve a successful experimental realisation of these scenarios in present-day tokamaks.
Źródło:
Nukleonika; 2012, 57, 1; 31-35
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application possibilities of electric driven propulsion of multi-mode ships
Autorzy:
Herdzik, J.
Powiązania:
https://bibliotekanauki.pl/articles/246217.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ships propulsion
electric propulsion
multi-mode ships
propulsion systems
Opis:
The ship propulsion solution based on unconventional thrusters driven by electric motors is most often applied for the multi-mode ships. These ships ought to have dynamic positioning system. It forces an application of a few thrusters (most often four, seldom more up to eight). Records from a number of multi-mode ships show amean load of less than 40% of maximum load on the propulsion system. In other side the demand for electric energy of ship industrial part is large, more often than for the propulsion part. In that case the diesel-electric propulsion system application may be economical, because the electric energy generation for all ship's purposes makes possible the main engines work on the optimum loads on lowest specific fuel consumption and allows them a long-term work on heavy fuels. For multi-mode ships like cable ships, suppliers, drilling vessels are convenient an application of unconventional thrusters with direct electric propulsion as well, especially for dynamic positioning systems. The efficiency of the thrusters is a predominant factor for the successful and economical operation. Forecasted development and rise of quantity of diesel-electric propulsion (it means with electrical transmission) would cause increased interest of unconventional thrusters. Ultimately they may revolutionize ship propulsion systems.
Źródło:
Journal of KONES; 2010, 17, 1; 163-168
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application possibilities of electric driven propulsion of multi-mode ships
Autorzy:
Herdzik, J.
Powiązania:
https://bibliotekanauki.pl/articles/247580.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ships propulsion
electric propulsion
multi-mode ships
propulsion systems
Opis:
The ship propulsion solution based on unconventional thrusters driven by electric motor s is most often applied for the multi-mode ships. These ships ought to have dynamic positioning system. It forces an application of a few thrusters (most often four, seldom more up to eight). Records from a number of multi-mode ships show a mean load of less than 40% of maximum load on the propulsion system. In other side the demand for electric energy of ship industrial part is large, more often than for the propulsion part. In that case the diesel-electric propulsion system application may be economical, because the electric energy generation for all ship 's purposes makes possible the main engines work on the optimum loads on lowest specific fuel consumption and allows them a long-term work on heavy fuels. For multi-mode ships like cable ships, suppliers, drilling vessels are convenient an application of unconventional thrusters with direct electric propulsion as well, especially for dynamic positioning systems. The efficiency of the thrusters is a predominant factor for the successful and economical operation. Forecasted development and rise of quantity of diesel-electric propulsion (it means with electrical transmission) would cause increased interest of unconventional thrusters. Ultimately they may revolutionize ship propulsion systems.
Źródło:
Journal of KONES; 2010, 17, 4; 177-183
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 1036

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