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Tytuł:
Impact oscillators : fundamentals and applications
Autorzy:
Trzaska, Z.
Powiązania:
https://bibliotekanauki.pl/articles/242533.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
nonlinear systems
impact oscillators
nonsmooth excitations
nonsmooth time transformation
hyperbolic numbers
Opis:
The paper presents results of the analysis of nonlinear oscillators with nonsmooth elements and nonlinear systems with nonsmooth forcing components. Main attention has been focused on highlighting specific properties of nonsmooth systems compared to their smooth counterparts. Nonsmooth transformation of the time variable and the replacement of initial issues by boundary problems have been taken as the base for the analytical method. Results of numerical simulations and computing in the form of graphs of displacements and velocity waveforms and attractors are presented. To fully identify the system's behaviour and meet high performance specifications recourse to model all dynamics together with their interactions has been taken into account. Strong interactions among the parts of the system are considered and the phenomenon of the impact is exhibited. It has been found that non-smooth dynamical systems reveal significant wealth of nonlinear phenomena, including a chaotic, that are unique to this potentially important class of nonlinear systems. In non-smooth systems at small change of parameters, a sudden transition from a stable periodic oscillation to the full range of chaotic oscillations may often occur. The dynamics of nonsmooth oscillations with shock external forcing is analysed by using a relatively new mathematical tool, which appears to be hyperbolic algebra. The key idea of this tool is steeped in of non-smooth time transformations (NSTT) for strongly nonlinear, but still smooth models.
Źródło:
Journal of KONES; 2015, 22, 1; 307-314
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Noise Analysis of Oscillators Based on Statistical Mechanics
Autorzy:
Thiessen, T.
Mathis, W.
Powiązania:
https://bibliotekanauki.pl/articles/226855.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear oscillators
thermal noise
statistical mechanics
Opis:
In this paper a new approach of thermal noise analysis of electronic oscillators is presented. Although nonlinear electronic oscillators are one of the most essential subcircuits in electronic systems typical design concepts for these oscillators are based on ideas of linear circuits. Because the functionality of oscillators depends on nonlinearities, advanced design methods are developed where nonlinearities are an integral part. Since low voltage oscillator concepts have to be developed in modern IC technologies there is a need to include at least thermal noise aspects into the design flow. For this reason we developed new physical descriptions of thermal noise in electronic oscillators where we use ideas from nonequilibrium statistical mechanics as well as the Langevin approach. We illustrate our concepts by some examples.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 4; 357-366
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metamorphoses of resonance curves in systems of coupled oscillators
Autorzy:
Kyzioł, J.
Okniński, A.
Powiązania:
https://bibliotekanauki.pl/articles/279900.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
coupled oscillators
amplitude profiles
singular points
Opis:
We study dynamics of two coupled periodically driven oscillators in a general case and compare it with two simplified models. Periodic steady-state solutions to these system equations are determined within the Krylov-Bogoliubov-Mitropolsky approach. Amplitude profiles are computed. These two equations, each describing a surface, define a 3D curve – intersection of these surfaces. In the present paper, we analyse metamorphoses of amplitude profiles induced by changes of control parameters in three dynamical systems studied. It is shown that changes of the dynamics occur in the vicinity of singular points of these 3D curves.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1197-1204
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization of mechanical oscillators excited kinematically
Synchronizacja oscylatorów mechanicznych wymuszanych kinematycznie
Autorzy:
Perlikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/281780.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
synchronizacja
oscylatory mechaniczne
pobudzenie kinematyczne
synchronization
mechanical oscillators
kinematic excitation
Opis:
In this paper, the behaviour of a system of coupled mechanical oscillators excited kinematically was studied numerically. Several methods of detection of synchronization were shown and advantages of each were mentioned. The relation between Lyapunov exponents and the synchronization state under different kinds of the excitation signal (harmonic, periodic and chaotic ones) was presented. It was demonstrated that the mode locking with excitation was dependent only on inner damping and completely uncorrelated with the connection between oscillators.
W artykule pokazano numeryczną analizę dynamiki sprzężonych oscylatorów mechanicznych wymuszonych kinematycznie. Przedstawiono przegląd najważniejszych metod detekcji synchronizacji, zwracając szczególną uwagę na ich własności. Następnie opisano powiązania między widmem wykładników Lapunowa, a różnymi typami synchronizacji. Zbadano odpowiedź układu dla różnych typów sygnału wymuszającego (harmonicznego, okresowego i chaotycznego). Udowodniono, że zamykanie modów pomiędzy sygnałem oscylatora a wymuszeniem zależne jest tylko od tłumienia wewnętrznego oscylatorów, natomiast jest niezależne od sprzężeń pomiędzy nimi.
Źródło:
Journal of Theoretical and Applied Mechanics; 2008, 46, 1; 185-204
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Acoustic Wave Oscillators
Autorzy:
Sehmisch, Dieter
Trzeba, Erich
Powiązania:
https://bibliotekanauki.pl/articles/896299.pdf
Data publikacji:
1990
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Opis:
Then: are principal advances in the field of application of surface acoustic wave (SAW) delay lines and resonators in stable microwave frequency sources in the frequency range from 100 MHz to 1 GHz and above Advances, applications and fundamental design will be described. The center frequencies of the realized oscillators are near 70 MHz and 200 MHz. Requirements for the amplifier are presented Results from frequency variation and modulation are demonstrated. Miniature SAW oscillators have been designed and fabricated based upon a combination of hybrid electronic circuitry and SAW delay line. The package for the oscillator is a PDL 24 with a volume of 28 X 34 X 5 mm³ This results in a rugged system Measurements of short and medium term stability of the oscillators will be described.
Źródło:
Acta Physicae Superficierum; 1990, 2
0867-2997
Pojawia się w:
Acta Physicae Superficierum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loop Gain of the Common-Drain Colpitts Oscillator
Autorzy:
Kazimierczuk, M. K.
Murthy-Bellur, D.
Powiązania:
https://bibliotekanauki.pl/articles/226711.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
band-pass feedback networks
Colpitts oscillator
common-drain amplifier
location of poles
loop gain
oscillation conditions
positive feedback
resonant oscillators
tuned oscillators
voltage-controlled oscillators (VCO)
Opis:
This paper presents the derivations of the voltage transfer functions of the amplifier A, the feedback network β, and the loop gain Τ of the common-drain (CD) Colpitts oscillator, using the small-signal model of the CD Colpitts oscillator. The derivation of the characteristic equation of the CD Colpitts oscillator is presented. Using the characteristic equation, the equation for the oscillation frequency of the sinusoidal output voltage and the condition for steady-state oscillation are derived. The characteristic equation is used to obtain a plot of trajectories of the poles of the CD Colpitts oscillator by varying the MOSFET small-signal transconductance gm. The locations of the complex conjugate poles depicting starting and steady-state conditions for oscillations are also presented.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 4; 423-426
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronisation and periodisation of duffing oscillators coupled by elastic beam: finite element method approach
Synchronizacja mechanicznych oscylatorów Duffinga zamocowanych na elastycznej belce
Autorzy:
Chudzik, A.
Powiązania:
https://bibliotekanauki.pl/articles/280007.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
oscillators
elastic structure
frequency
Opis:
Results of numerical analysis of a structure witch consists of two identical chaotic oscillators suspended on an elastic element are presented. The numerical calculations have been carried out with the use of the professional ANSYS software (User's Gude ANSYS 10). The findings show that for given conditions of the excitation, the initially uncollerated chaotic oscillations of the structure become periodic and synchronous.
W artykule przedstawiono wyniki analizy numerycznej struktury składającej się z dwóch identycznych chaotycznych oscylatorów zawieszonych na sprężystej belce. Obliczenia numeryczne przeprowadzono stosując profesjonalny pakiet programu ANSYS. Wykazano, że dla danych warunków wzbudzenia, początkowo nie są skorelowane, chaotyczne oscylacje struktury stają się okresowe i synchroniczne. W warunkach, kiedy częstości wzbudzenia różnią się, zjawiska powyższe nie występują.
Źródło:
Journal of Theoretical and Applied Mechanics; 2010, 48, 2; 517-524
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Random Number Generator Using Ring Oscillators and SHA-256 as Post-Processing
Autorzy:
Łoza, S.
Matuszewski, Ł.
Jessa, M.
Powiązania:
https://bibliotekanauki.pl/articles/963943.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
random numbers
cryptography
ring oscillators
hash functions
field programmable gate array (FPGA)
Opis:
Today, cryptographic security depends primarily on having strong keys and keeping them secret. The keys should be produced by a reliable and robust to external manipulations generators of random numbers. To hamper different attacks, the generators should be implemented in the same chip as a cryptographic system using random numbers. It forces a designer to create a random number generator purely digitally. Unfortunately, the obtained sequences are biased and do not pass many statistical tests. Therefore an output of the random number generator has to be subjected to a transformation called postprocessing. In this paper the hash function SHA-256 as postprocessing of bits produced by a combined random bit generator using jitter observed in ring oscillators (ROs) is proposed. All components – the random number generator and the SHA-256, are implemented in a single Field Programmable Gate Array (FPGA). We expect that the proposed solution, implemented in the same FPGA together with a cryptographic system, is more attack-resistant owing to many sources of randomness with significantly different nominal frequencies.
Źródło:
International Journal of Electronics and Telecommunications; 2015, 61, 2; 199-204
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of coupled neural oscillators for image texture segmentation and modeling of biological rhythms
Autorzy:
Strumiłło, P.
Strzelecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/908378.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
rytm biologiczny
oscylacja nieliniowa
stymulator serca
biological rhythms
nonlinear oscillations
networks of synchronised oscillators
texture segmentation
cardiac pacemakers
Opis:
The role of relaxation oscillator models in application fields such as modeling dynamic systems and image analysis is discussed. A short review of the Van der Pol,Wilson-Cowan and Terman-Wang relaxation oscillators is given. The key property of such nonlinear oscillators, i.e., the oscillator phase shift (called the Phase Response Curve) as a result of external pulse stimuli is indicated as a fundamental mechanism to achieve and sustain synchrony in networks of coupled oscillators. It is noted that networks of such oscillators resemble a variety of naturally occurring phenomena (e.g., in electrophysiology) and dynamics arising in engineering systems. Two types of oscillator networks exhibiting synchronous behaviors are discussed. The network of oscillators connected in series for modeling a cardiac conduction system is used to explain causes of important cardiac abnormal rhythms. Finally, it is shown that a 2D network of coupled oscillators is an effective tool for segmenting image textures in biomedical images.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2006, 16, 4; 513-523
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aging of ground Global Navigation Satellite System oscillators
Autorzy:
Maciuk, Kamil
Powiązania:
https://bibliotekanauki.pl/articles/2087021.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
clock
GNSS
oscillator
positioning
time
Opis:
Global Navigation Satellite System (GNSS) are widely used in many areas of human life and activity. The proper functioning of GNSS systems depends on several factors, the most important of which is the correct knowledge of time. The position indirectly is based on the knowledge of the distance, which is determined based on time with the knowledge of the speed of the electromagnetic wave. Thus, proper (accurate) knowledge of time (GNSS clock stability) is a key to precise positioning. In this text, the long-term stability of the GNSS station clocks covering the years 1994-2020 was analysed. For this purpose, the corrections of the clocks at selected permanent stations were used, and their stability was determined for all years separately. Then the change of clock stability over time and the search for correlation were analysed. As the results showed, there are clearly differences between four of the type of oscillators analysed. In case of the comparison on an annual basis, no change over time was found.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 2; 371--376
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forecasting models for chaotic fractional-order oscillators using neural networks
Autorzy:
Bingi, Kishore
Prusty, B Rajanarayan
Powiązania:
https://bibliotekanauki.pl/articles/2055150.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
chaotic oscillators
data driven forecasting
fractional order system
model free analysis
neural network
time series prediction
oscylator chaotyczny
układ rzędu ułamkowego
sieć neuronowa
prognozowanie szeregów czasowych
Opis:
This paper proposes novel forecasting models for fractional-order chaotic oscillators, such as Duffing’s, Van der Pol’s, Tamaševičius’s and Chua’s, using feedforward neural networks. The models predict a change in the state values which bears a weighted relationship with the oscillator states. Such an arrangement is a suitable candidate model for out-of-sample forecasting of system states. The proposed neural network-assisted weighted model is applied to the above oscillators. The improved out-of-sample forecasting results of the proposed modeling strategy compared with the literature are comprehensively analyzed. The proposed models corresponding to the optimal weights result in the least mean square error (MSE) for all the system states. Further, the MSE for the proposed model is less in most of the oscillators compared with the one reported in the literature. The proposed prediction model’s out-of-sample forecasting plots show the best tracking ability to approximate future state values.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 3; 387--398
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hamiltonian Approach to Multiple Coupled Nonlinear Oscillators
Autorzy:
Durmaz, S.
Altay Demirbag, S.
Kaya, M.
Powiązania:
https://bibliotekanauki.pl/articles/1490743.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.-a
46.40.-f
Opis:
In this paper, Hamiltonian approach is extended to investigate coupled nonlinear multi-degree-of-freedom oscillatory systems. At the beginning of the study, basic principles of Hamiltonian approach are provided for multiple coupled oscillators. In the next section, the amplitude-frequency relation for the two-degree-of-freedom nonlinear mechanical systems is obtained via Hamiltonian approach. The natural frequency expression is compared to show the agreement between the present and published results. Additionally, the approximate and numerical periodic solutions are plotted.
Źródło:
Acta Physica Polonica A; 2012, 121, 1; 47-49
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applicability of Different SAW Oscillators Topologies for High Frequency Gas Sensors Construction
Autorzy:
Pasternak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1506822.pdf
Data publikacji:
2010-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
46.35.+z
68.35.Ja
Opis:
In general, there are three possible kinds of surface acoustic wave devices that may be applied for high frequency gas sensor construction: delay lines, one- and two-port resonators. Choice among them depends on individual preferences and sometimes it is the matter of chance. In the paper the key differences among the surface acoustic wave devices important from the gas sensors technology point of view are described.
Źródło:
Acta Physica Polonica A; 2010, 118, 6; 1232-1234
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control and chaos for vibro-impact and non-ideal oscillators
Sterowanie i chaos w układach drgających z uderzeniami oraz nieidealnych oscylatorów
Autorzy:
de Souza, S. L. T.
Caldas, I. L.
Viana, R. L.
Balthazar, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/280889.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
chaos
kontrola chaosu
wibracje z uderzeniem
vibro-impact
control of chaos
non-ideal oscillators
Opis:
In the paper, we discuss dynamics of two kinds of mechanical systems. Initially, we consider vibro-impact systems which have many implemen- tations in applied mechanics, ranging from drilling machinery and metal cutting processes to gear boxes. Moreover, from the point of view of dynamical systems, vibro-impact systems exhibit a rich variety of phe- nomena, particularly chaotic motion. In this paper, we review recent works on the dynamics of vibro-impact systems, focusing on chaotic mo- tion and its control. The considered systems are a gear-rattling model and a smart damper to suppress chaotic motion. Furthermore, we inve- stigate systems with non-ideal energy source, represented by a limited power supply. As an example of a non-ideal system, we analyse chaotic dynamics of the damped Duffing oscillator coupled to a rotor. Then, we show how to use a tuned liquid damper to control the attractors of this non-ideal oscillator.
W pracy przedyskutowano zagadnienie dynamiki mechanizmów dwóch rodzajów. Najpierw rozważono układ drgający z uderzeniami, który znajduje liczne aplikacje praktyczne w mechanice stosowanej, począwszy od urządzeń wiertniczych przez procesy cięcia metalu do skrzyń biegów włącznie. Z punktu widzenia dynamiki maszyn układy wibro-uderzeniowe wykazują bogactwo interesujących zjawisk, wliczając w to chaos. W pracy zaprezentowano przegląd ostatnich prac dotyczących dynamiki układów wibro-uderzeniowych, w których zajęto się problemem chaosu i możliwości jego sterowania. Przeanalizowano układy mechaniczne na przykładzie modelu kół zębatych z systemem ”inteligentnego” tłumika do eliminacji ruchu chaotycznego. Zajęto się, po drugie, mechanizmami z nieidealnym źródłem energii odwzorowanym poprzez układ ograniczonego poboru mocy. Jako przykład zbadano dynamikę chaotyczną tłumionego oscylatora Duffinga połączonego z wirnikiem. Pokazano sposób zastosowania płynnego tłumika do sterowania formą atraktorów obserwowanych w nieidealnym oscylatorze.
Źródło:
Journal of Theoretical and Applied Mechanics; 2008, 46, 3; 641-664
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Producing Random Bits with Delay-Line-Based Ring Oscillators
Autorzy:
Jessa, M.
Matuszewski, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/227302.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ring oscillator
jitter
random bit generator
combined generator
Opis:
One of the sources of randomness for a random bit generator (RBG) is jitter present in rectangular signals produced by ring oscillators (ROs). This paper presents a novel approach for the design of delays used in these oscillators. We suggest using delay elements made on carry4 primitives instead of series of inverters or latches considered in the literature. It enables the construction of many high frequency ring oscillators with different nominal frequencies in the same field programmable gate array (FPGA). To assess the unpredictability of bits produced by RO-based RBG, the restarts mechanism, proposed in earlier papers, was used. The output sequences pass all NIST 800-22 statistical tests for smaller number of ring oscillators than the constructions described in the literature. Due to the number of ROs with different nominal frequencies and the method of construction of carry4 primitives, it is expected that the proposed RBG is more robust to cryptographic attacks than RBGs using inverters or latches as delay element.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 1; 41-50
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaotic vibration of an autoparametrical system with the spherical pendulum
Autorzy:
Sado, D.
Freundlich, J.
Bobrowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/281820.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
spherical pendulum
energy transfer
coupled oscillators
chaos
Opis:
In the paper, the dynamics of a three degree of freedom vibratory system with a spherical pendulum in the neighbourhood of internal and external resonance is considered. It has been assumed that the spherical pendulum is suspended to the main body which is then suspended to the element characterized by some elasticity and damping. The system is excited harmonically in the vertical direction. The equation of motion has been solved numerically. The influence of initial conditions on the behaviour of the spherical pendulum is investigated. In this type of the system, one mode of vibration may excite or damp another one, and for different kinds of periodic vibrations there may also appear chaotic vibrations. For characterization of an irregular chaotic response, time histories, bifurcation diagrams, power spectral densities, Poincar´e maps and the maximum Lyapunov exponents have been calculated.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 3; 779-786
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization of two forced double-well Duffing oscillators with attached pendulums
Autorzy:
Brzeski, P.
Karmazyn, A.
Perlikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/280968.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Duffing pendulum system
bifurcational analysis
synchronization
Opis:
We investigate the dynamics of two coupled Duffing oscillators with attached pendulums forced kinematically by a common signal. Our attention is focused on different kinds of synchronization which can appear in the considered system. Different types of coupling (spring, damper and spring and damper simultaneously) are taken into account. We show in a two-parameters space (amplitude and frequency of excitation) existence of complete and phase synchronization and asynchronous ranges.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 3; 603-613
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Noise Minimization in CMOS Voltage Controlled Oscillators
Autorzy:
Charlamov, J.
Navickas, R.
Baskys, A.
Powiązania:
https://bibliotekanauki.pl/articles/1506209.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.40.-e
85.40.Qx
07.50.Hp
Opis:
Relaxation RC type voltage controlled oscillator is more desirable for many applications because of wide frequency generation range, small size on chip and linear voltage to frequency transfer characteristic. The limiting factor of such voltage controlled oscillator type is that it has higher phase noise in comparison with liquid crystal oscillators. We discuss how different device components, parameters and configuration influence phase noise, including transistor noise sources dependence on its geometrical parameters. The simulation results of the relaxation voltage controlled oscillator which was implemented in different 180 nm and 90 nm CMOS technologies are reported.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 234-236
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Avoidance of artifacts in harmonic balance solutions for nonlinear dynamical systems
Autorzy:
Lentz, Lukas
von Wagner, Utz
Powiązania:
https://bibliotekanauki.pl/articles/1839629.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nonlinear systems
harmonic balance
artifacts
Duffing oscillators
Opis:
Although nonlinear mechanical systems have been the topic of numerous investigations during the last decades, the research on suitable analysis methods is still ongoing. One method that is commonly known and still sees a lot of interest is the Harmonic Balance method. In the basic version of this method, only one harmonic is used to approximate a periodic solution, which allows for fairly easy application. A drawback is that this approach may lead to solutions that are inaccurate or even artifacts which are solutions that possess no physical relevance. In this article, it is demonstrated how an error criterion can be used to access the accuraccy of solutions and how artifacts can be indentified based on this assessment. Subsequently, stability analysis is performed for solutions that possess small errors. The method is applied to an asymmetric Duffing oscillator as well as to a system that consists of two linearly coupled Duffing oscillators. The authors gave a corresponding presentation of their work at PCM-CCM Kraków 2019.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 2; 307-316
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Suppressing Activity of an Array of Coupled Fitzhugh-Nagumo Oscillators
Autorzy:
Adomaitienė, E.
Mykolaitis, G.
Bumelienė, S.
Tamaševičius, A.
Powiązania:
https://bibliotekanauki.pl/articles/1398724.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.Xt
87.19.lr
Opis:
An extremely simple method for stabilizing unstable steady states in an array of coupled neuronal FitzHugh-Nagumo type oscillators is described. A two-terminal electronic feedback controller has been developed. The feedback circuit, when coupled to an array of oscillators, damps the spiking neurons, thus does away with the effect of synchronization. Both, numerical simulations and hardware experiments with the electronic circuits have been performed. The results for an array of three mean-field coupled FitzHugh-Nagumo oscillators are presented.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 562-564
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Invariants for Time-Dependent Harmonic Oscillators from the Real Representation of Solution
Autorzy:
Liang, M.-L.
Zhang, Z.-G.
Yuan, B.
Powiązania:
https://bibliotekanauki.pl/articles/2037140.pdf
Data publikacji:
2004-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
45.20.Jj
03.65.-w
Opis:
The invariants for the time-dependent one-dimensional harmonic oscillator and the time-dependent two-dimensional harmonic oscillator in a static magnetic field are derived from the real representation of the exact solution to the equation of motion. Mathematically, the orthogonal functions invariant is the angular momentum of an isotropic time-dependent two-dimensional harmonic oscillator. Based on the invariants obtained here, the wave function for time-dependent two-dimensional harmonic oscillator in a static magnetic field in cylindrical coordinate is simply derived and the dynamical and geometrical phases are easily got by expressing the wave function as the superpositions of the wave functions of time-dependent two-dimensional harmonic oscillator in rectangular coordinate. For the driven system, the driving induced dynamical phase and the geometrical phase are respectively associated with the classical Hamiltonian and de Broglie wave of the center motion of the wave function.
Źródło:
Acta Physica Polonica A; 2004, 105, 3; 253-262
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local Real Estate Markets in Poland as a Network of Damped Harmonic Oscillators
Autorzy:
Kulesza, S.
Belej, M.
Powiązania:
https://bibliotekanauki.pl/articles/1388528.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Ln
89.65.Gh
89.75.Da
Opis:
The paper deals with time series of housing prices on local real estate markets in Warszawa (WAW), Kraków (KRK) and Poznań (POZ) from 2006 to 2013 using a model of critically-damped harmonic oscillator to study underlying system dynamics. Performed analysis reveals the presence of housing bubble in 2007 that emerge from otherwise quasi-regular evolution around the equilibrium state. Time series of housing prices are fitted numerically to estimate important parameters of the system, for example: decay constant, delay time, and price equilibrium level, which help us to chose the leading market. Obtained results show reasonable matching of the model with housing prices in WAW and POZ, but less in KRK. The latter data, however, are found to agree well with the model of under-damped harmonic oscillator, which actually suggests that some trembling might occur in that market. Nevertheless, local real estate markets can be thought of as a system of interconnected damped harmonic oscillators with leading market in WAW that is about to change under aggregate macroeconomic fluctuations (exogenous factors) triggering changes in remaining markets.
Źródło:
Acta Physica Polonica A; 2015, 127, 3A; A-99-A-102
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study of divers oscillators
Porównawcze badania różnych oscylatorów
Autorzy:
Karaliunas, B.
Shulskis, D.
Powiązania:
https://bibliotekanauki.pl/articles/159114.pdf
Data publikacji:
2006
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
neuron
oscylator
oscylator Hodgkin-Huxley
Hodgkin-Huxley oscillator
serial interconnection
feedback loop interconnection
Opis:
In this paper several classical neural oscillators (FitzHugh-Nagumo, Van der Pol, Hodgkin-Huxley) were studied. Although there are many known different oscillators, the Hodgkin-Huxley oscillator was more deeply investigated. Systems of two interconnected Hodgkin-Huxley neurons were also analyzed. Relationships between frequency and input current amplitude were found.
Artykuł omawia kilka klasycznych oscylatorów neutralnych (FitzHug-Nagumo, Van der Pol, Hodgkin-Huxley). Jakkolwiek znanych jest wiele różnych oscylatorów, jednak oscylator Hodgkin-Huxley został zbadany dokładniej. Przeanalizowano też układy dwu połączonych neuronów Hodgkin-Huxley. Podano zależność częstotliwości od amplitudy prądu wejściowego.
Źródło:
Prace Instytutu Elektrotechniki; 2006, 226; 19-44
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal analysis of CMOS voltage-controlled oscillators
Analizy termiczne generatorów przestrajanych napięciem
Autorzy:
Frankiewicz, M.
Kos, A.
Powiązania:
https://bibliotekanauki.pl/articles/408120.pdf
Data publikacji:
2012
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
VCO
układy rezonansowe
generatory pierścieniowe
CMOS
temperatura
LC
RO
temperature
Opis:
The paper presents impact of chip temperature on frequency generated by Voltage-Controlled Oscillators. Three different CMOS structures have been tested. Resonant cross-coupled oscillator was designed and fabricated in AMS 0.35 žm (3.3 V) technology and has at ambient temperature the frequency range from 2.2 to 2.5 MHz. Two different ring oscillators were designed in UMC 0.18 žm (1.8 V) technology and have at ambient temperature the frequency range respectively from 0.6 to 2.8 GHz and from 0.4 to 1.9 GHz. All circuits were designed using full-custom technique. Influence of temperature to tuning range and power consumption has been investigated.
Artykuł przedstawia wpływ temperatury na działanie generatorów przestrajanych napięciem VCO. Przebadane zostały trzy różne struktury układów CMOS. Generator rezonansowy został zaprojektowany i sfabrykowany w technologii AMS 0,35 žm (3,3 V) i w temperaturze pokojowej generuje częstotliwości z zakresu ad 2,2 do 2,5 MHz. Dwa odmienne generatory pierścieniowe zostały zaprojektowane w technologii UMC 0,18 žm (1,8 V) i generują częstotliwości z zakresu odpowiednio od 0,6 do 2,8 GHz oraz od 0,4 do 1,9 GHz. Wszystkie układy zostały zaprojektowane techniką full-custom. Przetestowane zostało oddziaływanie termiczne na zakres przestrajania oraz pobór mocy generatorów.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2012, 4b; 3-6
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fluidic generator of microbubbles : oscillator with gas flow reversal for a part of period
Autorzy:
Tesař, V.
Powiązania:
https://bibliotekanauki.pl/articles/387490.pdf
Data publikacji:
2015
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
fluidics
oscillators
microbubbles
u-tube resonator
oscylator
mikropęcherzyki
technika strumieniowa
rezonator
Opis:
Paper presents a fluidic device developed for generation of small (less than 1 mm in diameter) microbubbles in a liquid from gas passing gas through small passages. Until now the bubbles are larger than the size of aerator passage exits so that making the passages smaller did not result in obtaining the desirable microbubbles. Analysis of high-speed camera images (obtained with a special lens of large working distance) have shown show that the large bubble size is caused by slow ascent motion of very small bubbles so that they get into mutual contact and grow by conjunction. The solution is to pulsate the supplied gas flow by a no-moving-part fluidic oscillator. The gener-ated small bubble is moved back into the aerator passage where it is for a part of oscillation period protected from the conjunction with other, previously generated microbubbles.
Źródło:
Acta Mechanica et Automatica; 2015, 9, 4; 195-203
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
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