Статті в журналах: "Switching oscillation"

1

Gu, Meiyuan, Guangyi Wang, Jingbiao Liu, Yan Liang, Yujiao Dong, and Jiajie Ying. "Dynamics of a Bistable Current-Controlled Locally-Active Memristor." International Journal of Bifurcation and Chaos 31, no. 06 (May 2021): 2130018. http://dx.doi.org/10.1142/s0218127421300184.

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This paper presents a novel current-controlled locally-active memristor model to reveal the switching and oscillating characteristics of locally-active devices. It is shown that the memristor has two asymptotically stable equilibrium points on its power-off plot and therefore exhibits nonvolatility. Switching from one stable equilibrium point to another is achieved by applying a suitable current pulse. The locally-active characteristic of the memristor is measured by the DC [Formula: see text]–[Formula: see text] plot. A small-signal equivalent circuit on a locally-active operating point with the bias current [Formula: see text] is constructed for describing the characteristic of the locally-active region of the memristor. A periodic oscillator circuit composed of the locally-active memristor, a compensation inductor and a resistor is proposed, whose dynamics is analyzed in detail by using the Hopf bifurcation and the zeros and poles of the impendence function of the circuit. It is found that the locally-active memristor based circuit with different current biases or different initial conditions can exhibit different dynamics such as periodic oscillation and stable equilibrium point. If an energy storage element (capacitor) is added to the periodic oscillation circuit, a chaotic oscillator is obtained, which can exhibit abundant dynamics. The oscillation mechanism of the memristor-based oscillator is analyzed via dynamic route map (DRM), showing that the memristor is an essential device for generating periodic and chaotic oscillations, and its local activity is the cause for complex oscillations.

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2

Shao, Zhu Lei. "Design of CMOS Sawtooth Wave Oscillator for Switching Power Supply." Advanced Materials Research 960-961 (June 2014): 1268–71. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.1268.

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Based on the CMOS technology, the sawtooth wave oscillator used in switching power supply is designed. In the condition of 27 °C and 4 V power supply voltage, the oscillation frequency of sawtooth wave oscillator is 246.61 KHz. The oscillation frequency of sawtooth wave oscillator changes between 245.94 KHz and 247.89 KHz when the power supply voltage changes between 3V and 6V. The maximum deviation is ±0.52%. From the experimental results, the sawtooth wave oscillator has good linearity, the effect of temperature and power supply to the oscillation frequency of sawtooth wave oscillator is very little. The CMOS sawtooth wave oscillator is suitable for switching power supply.

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3

Bao, Weili, and Jian-Young Wu. "Propagating Wave and Irregular Dynamics: Spatiotemporal Patterns of Cholinergic Theta Oscillations in Neocortex In Vitro." Journal of Neurophysiology 90, no. 1 (July 2003): 333–41. http://dx.doi.org/10.1152/jn.00715.2002.

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Neocortical “theta” oscillation (5–12 Hz) has been observed in animals and human subjects but little is known about how the oscillation is organized in the cortical intrinsic networks. Here we use voltage-sensitive dye and optical imaging to study a carbachol/bicuculline induced theta (∼8 Hz) oscillation in rat neocortical slices. The imaging has large signal-to-noise ratio, allowing us to map the phase distribution over the neocortical tissue during the oscillation. The oscillation was organized as spontaneous epochs and each epoch was composed of a “first spike,” a “regular” period (with relatively stable frequency and amplitude), and an “irregular” period (with variable frequency and amplitude) of oscillations. During each cycle of the regular oscillation, one wave of activation propagated horizontally (parallel to the cortical lamina) across the cortical section at a velocity of ∼50 mm/s. Vertically the activity was synchronized through all cortical layers. This pattern of one propagating wave associated with one oscillation cycle was seen during all the regular cycles. The oscillation frequency varied noticeably at two neighboring horizontal locations (330 μm apart), suggesting that the oscillation is locally organized and each local oscillator is about ≤300 μm wide horizontally. During irregular oscillations, the spatiotemporal patterns were complex and sometimes the vertical synchronization decomposed, suggesting a de-coupling among local oscillators. Our data suggested that neocortical theta oscillation is sustained by multiple local oscillators. The coupling regime among the oscillators may determine the spatiotemporal pattern and switching between propagating waves and irregular patterns.

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4

Yamaguchi, Tomiharu, Emiyu Ogawa, and Akinori Ueno. "Short-Time Impedance Spectroscopy Using a Mode-Switching Nonsinusoidal Oscillator: Applicability to Biological Tissues and Continuous Measurement." Sensors 21, no. 21 (October 20, 2021): 6951. http://dx.doi.org/10.3390/s21216951.

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Herein, we propose an impedance spectroscopy method using a mode-switching nonsinusoidal oscillator and apply this method for measuring the impedance of biological tissues and continuous impedance measurement. To obtain impedance spectra over a wide frequency range, we fabricated a novel nonsinusoidal oscillator incorporating binary counters and analog switches. This oscillator could periodically switch oscillation frequency through the mode switching of the feedback resistor. From the oscillation waveform at each oscillation frequency of this circuit (oscillator), we determined the impedance spectrum of a measured object using the discrete-time Fourier transform. Subsequently, we obtained the broad impedance spectrum of the measured object by merging odd-order harmonic spectral components up to the 19th order for each oscillation frequency. From the measured spectrum, the resistive and capacitive components of the circuit simulating bioimpedance were estimated with high accuracy. Moreover, the proposed method was used to measure the impedance of porcine myocardium; changes in the impedance spectrum of the myocardial tissue due to coagulation could be measured. Furthermore, rapid variations in the resistance value of a CdS photocell could be continuously measured using the proposed method.

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5

Liu, Huanhuan, Lijuan Liang, Li Zhang, Yao Lu, and Baoguo Chen. "Modulatory role of inhibition during language switching: Evidence from evoked and induced oscillatory activity." International Journal of Bilingualism 21, no. 1 (July 26, 2016): 57–80. http://dx.doi.org/10.1177/1367006915600800.

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Aims: The present study adopted the electroencephalogram (EEG) technique to investigate whether inhibition advantage could modulate different language switches, regardless of the time spent on second language learning. Design: The inhibitory control (IC) ability of 80 low-proficient Chinese (L1)-English (L2) bilinguals was assessed by the Simon task. Half of these bilinguals were then subdivided into 20 high- and 20 low-IC participants to perform switching between L1 and L2 (L1–L2 switching), and the other half were subdivided into 20 high- and 20 low-IC participants to conduct switching between L1 and Lnew (L1–Lnew switching). All participants were required to name pictures (picture naming task) in their L1 and L2/Lnew in language switching task. Data and analysis: Both response latencies and EEG data were obtained, and then evoked and induced oscillations were calculated using time–frequency analysis. Findings: The results of language switching showed similar naming latencies for L1 and L2/Lnew switch trials in the high-IC group, whereas the low-IC group showed larger naming latencies for L1 switch trials than L2/Lnew switch trials. In contrast, the high-IC group exhibited larger theta evoked and induced power for L2/Lnew switch trials than L1 switch trials at the lexical selection level, whereas the low-IC group did not. These findings indicate that inhibition advantage helps the high-IC group to suppress effectively the non-target word via recruiting bottom-up (evoked oscillation) and top-down (induced oscillation) processes. Innovation: The present study was a first attempt to provide evidence that theta oscillation indicates cross-language interference at the lexical selection level. Significance: Inhibition plays a modulatory role in language switching, which is independent of the time spent on second language learning, and such role involves bottom-up (i.e., evoked oscillation) and top-down (i.e., induced oscillation) processes which were mainly evident at the lexical selection level.

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6

Zhang, Mingsheng, Tiejun Zhou, and Zhimin Yuan. "Analysis of Switchable Spin Torque Oscillator for Microwave Assisted Magnetic Recording." Advances in Condensed Matter Physics 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/457456.

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A switchable spin torque oscillator (STO) with a negative magnetic anisotropy oscillation layer for microwave assisted magnetic recording is analyzed theoretically and numerically. The equations for finding the STO frequency and oscillation angle are derived from Landau-Lifshitz-Gilbert (LLG) equation with the spin torque term in spherical coordinates. The theoretical analysis shows that the STO oscillating frequency remains the same and oscillation direction reverses after the switching of the magnetization of the spin polarization layer under applied alternative magnetic field. Numerical analysis based on the derived equations shows that the oscillation angle increases with the increase of the negative anisotropy energy density (absolute value) but decreases with the increase of spin current, the polarization of conduction electrons, the saturation magnetization, and the total applied magnetic field in thezdirection. The STO frequency increases with the increase of spin current, the polarization of conduction electrons, and the negative anisotropy energy density (absolute value) but decreases with the increase of the saturation magnetization and the total applied magnetic field in thezdirection.

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7

Aboutalebi, Payam, Fares M’zoughi, Itziar Martija, Izaskun Garrido, and Aitor J. Garrido. "Switching Control Strategy for Oscillating Water Columns Based on Response Amplitude Operators for Floating Offshore Wind Turbines Stabilization." Applied Sciences 11, no. 11 (June 5, 2021): 5249. http://dx.doi.org/10.3390/app11115249.

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In this article, a new strategy for switching control has been proposed with the aim of reducing oscillations in floating offshore wind turbines. Such oscillations lead to a shortage in the system’s efficiency, lifespan and harvesting capability of wind and wave energies. In order to study the decreasing of undesired oscillations in the system, particularly in pitch and top tower fore-aft movements, a square-shaped platform barge equipped with four symmetric oscillating water columns has been considered. The oscillating water columns’ air flux valves allow to operate the air columns so that to control the barge movements caused by oscillatory motion of the waves. In order to design the control scheme, response amplitude operators have been used to evaluate the performance of the system for a range of wave frequency profiles. These response amplitude operators analysis makes it possible to implement a switching control strategy to adequately regulate the valves opening/closing transition. The obtained results show that the proposed controlled oscillating water column-based barge present a better performance compared to the traditional barge one. In the case study with the period of 10 s, the results indicate the significant oscillation reduction for the controlled oscillating water column-based system compared to the standard barge system by 30.8% in pitch angle and 25% in fore-aft displacement.

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8

KAO, C. H., P. Y. TSAI, W. P. LIN, and M. C. CHOU. "A SELF-OSCILLATING SWITCHING POWER AMPLIFIER." Journal of Circuits, Systems and Computers 18, no. 01 (February 2009): 67–79. http://dx.doi.org/10.1142/s0218126609004934.

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A self-oscillating switching power amplifier is proposed. We use feedback to reduce the output DC bias current and to produce self-oscillation. Further, filters are added in the feedback loop to reduce the quantization noise. The experimental results show that the proposed circuit has 0.25% total harmonic distortion (THD) and the efficiency of output power of 840 μW reaches 90.1% while the DC output bias current is 8 μA and the supply voltage is 1.5 V.

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9

Maltsev, S. N., V. Yu Konev, V. V. Barmin, I. V. Romanchenko, and I. A. Prudaev. "Radiopulse generation in dispersive nonlinear transmission lines with GaAs S-diodes." Journal of Physics: Conference Series 2094, no. 2 (November 1, 2021): 022065. http://dx.doi.org/10.1088/1742-6596/2094/2/022065.

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Abstract The article discusses the regularities that increase the efficiency of generation of microwave oscillations in nonlinear dispersive lines with commutation diodes. GaAs semiconductor structures were used as switching diodes. The results of numerical simulations and experiments are presented, showing that the amplitude of microwave oscillations in the line increases with decreasing oscillation frequency.

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10

Shimizu, Kuniyasu. "Experimental Observations of Propagating Waves and Switching Phenomena in a Coupled Bistable Oscillator System." International Journal of Bifurcation and Chaos 24, no. 12 (December 2014): 1450157. http://dx.doi.org/10.1142/s0218127414501570.

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In this study, we construct a circuit composed of bistable oscillators and we report the experimental observations of quasi-periodic waves propagating in the circuit and compare them with the associated numerical results. Two different types of propagating quasi-periodic waves with identical parameter sets are experimentally verified. The associated numerical results are distinguished by comparing trajectories on the phase planes and by analyzing the one-parameter bifurcation diagrams. Furthermore, the experiments reveal five different types of switching oscillations. The associated numerical results are also presented, and the stability of the switching oscillations (when constrained to an invariant subspace) is numerically investigated. We also calculate spectral distribution for one type of the switching oscillation.

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11

Gorshkov, Oleg, Dmitry Filatov, Dmitry Antonov, and Ivan Antonov. "Noise and Electrical Oscillations Generation during the Investigation of the Resistive Switching in the Yttria Stabilized Zirconia Films by Conductive Atomic Force Microscopy." Advances in Condensed Matter Physics 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/104657.

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The effect of resistive switching in the yttria stabilized zirconia (YSZ) thin films on Si substrates has been studied by Conductive Atomic Force Microscopy (CAFM). The resistive switching of the YSZ films from the low conductive state to the highly conductive one has been found to be associated with the increasing of the noise with broad frequency spectrum related to the redistribution of the oxygen vacancies in YSZ. The electrical oscillations in oscillation loop connected in series to the CAFM probe, the sample, and the bias source related to the excitation of the oscillation loop by the noise in the probe-to-sample contact film have been observed. The effect discovered is promising for application in the memristor devices of new generation.

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12

Karmakar, Rajesh. "Two different modes of oscillation in a gene transcription regulatory network with interlinked positive and negative feedback loops." International Journal of Modern Physics C 27, no. 05 (May 2016): 1650056. http://dx.doi.org/10.1142/s012918311650056x.

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We study the oscillatory behavior of a gene regulatory network with interlinked positive and negative feedback loop. The frequency and amplitude are two important properties of oscillation. The studied network produces two different modes of oscillation. In one mode (mode-I), frequency of oscillation remains constant over a wide range of amplitude and in the other mode (mode-II) the amplitude of oscillation remains constant over a wide range of frequency. Our study reproduces both features of oscillations in a single gene regulatory network and shows that the negative plus positive feedback loops in gene regulatory network offer additional advantage. We identified the key parameters/variables responsible for different modes of oscillation. The network is flexible in switching between different modes by choosing appropriately the required parameters/variables.

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13

Wang, Faqiang, and Xikui Ma. "Research on the Influence of Switching Frequency on Low-Frequency Oscillation in the Voltage-Controlled Buck-Boost Converter." Mathematical Problems in Engineering 2011 (2011): 1–15. http://dx.doi.org/10.1155/2011/926403.

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The influence of switching frequency on the low-frequency oscillation in the voltage-controlled buck-boost converter is studied in this paper. Firstly, the mathematical model of this system is derived. And then, a glimpse at the influence of switching frequency on the low-frequency oscillation in this system by MATLAB/Simulink is given. The improved averaged model of the system is established, and the corresponding theoretical analysis is presented. It is found that the switching frequency has an important influence on the low-frequency oscillation in the system, that is, the low-frequency oscillation is easy to occur when the switching frequency is low. Finally, the effectiveness of the improved averaged model and the theoretical analysis are confirmed by circuit experiment.

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14

Yamasawa, Kiyohito, and Yukio Hirohama. "A Parametric-Oscillation Type Switching Regulator." IEEJ Transactions on Industry Applications 112, no. 3 (1992): 314–15. http://dx.doi.org/10.1541/ieejias.112.314.

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15

Raviola, Erica, and Franco Fiori. "Investigations on the Use of the Power Transistor Source Inductance to Mitigate the Electromagnetic Emission of Switching Power Circuits." Signals 2, no. 3 (September 6, 2021): 586–603. http://dx.doi.org/10.3390/signals2030036.

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With power designers always demanding for faster power switches, electromagnetic interference has become an issue of primary concern. As known, the commutation of power transistors is the main cause of the electromagnetic noise, which can be worsened by the presence of unwanted oscillations superimposed onto the switching waveforms. This work proposes a solution to mitigate the oscillations caused by the turn-on of a power transistor by exploiting its source inductance plus an external one. In this context, an optimization method is proposed to find the optimal value of the source inductance as a trade-off between oscillation damping and power dissipation. The experimental results performed on a prototyped power converter assess the proposed technique as the spectrum of the conducted emission is attenuated by 20 dB at the oscillation frequency. With respect to traditional solution based on snubbers, the proposed solution results in a similar oscillation damping, but with a 0.5% higher power efficiency.

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16

Преображенский, В. Л., Л. М. Крутянский, N. Tiercelin та P. Pernod. "Магнитоэлектроакустическая динамика в стрейнтронной ячейке памяти с произвольным доступом". Письма в журнал технической физики 46, № 1 (2020): 43. http://dx.doi.org/10.21883/pjtf.2020.01.48864.18056.

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Straintronic principle of nonvolatile magnetoelectric random access memory (MELRAM) draws much attention due to the prospects of ultra-low energy consumption in storage devices. The switching of magnetic moments by pulsed deformation of elastically coupled magnetic and piezoelectric subsystems is accompanied by excitation of acoustic oscillations in the memory cells. Oscillation period in nanoscale cells is comparable with the magnetic moment switching time, which can affect the information recording process. In the present paper the influence of acoustic excitations on the magnetic switching dynamics is studied by numerical modeling with application to a magnetostrictive cell 50×50×400 nm3 on a PMN-PT <011> substrate. Parameters of voltage control pulses that can insure reliable switching of magnetic states of the system are determined.

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17

Jiang, Hanhong, Yao Lu, You Wu, and Yi Wang. "The Strategy of Inverter Seamless Mode Switching in Master-Slave Independent Micro-grid." MATEC Web of Conferences 160 (2018): 04003. http://dx.doi.org/10.1051/matecconf/201816004003.

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In order to realize the uninterruptible power supply in the master-slave independent micro-grid system, the micro-grid inverter needs to realize the mode switching of the grid-connection/grid-disconnection. How to reduce the transient oscillation during switching, so as to effectively achieve seamless mode switching is a key issue to be solved. In this paper, a typical master-slave control independent micro-grid is used as an example, the strategy of mode switching is improved in two aspects. On the one hand, the state-following algorithm is adopted to improve the switching strategy of the outer loop. On the other hand, the current inner loop is taken by the H∞ robust controller to improve the robustness of the controller. Compared with the traditional PI control mode switching, this paper illustrates the feasibility of the proposed strategy through the simulation and experiment verification. The improvement strategy in this paper can effectively reduce the voltage and current oscillation during mode switching.

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18

Boriskov, Petr, Andrei Velichko, Nikolay Shilovsky, and Maksim Belyaev. "Bifurcation and Entropy Analysis of a Chaotic Spike Oscillator Circuit Based on the S-Switch." Entropy 24, no. 11 (November 19, 2022): 1693. http://dx.doi.org/10.3390/e24111693.

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This paper presents a model and experimental study of a chaotic spike oscillator based on a leaky integrate-and-fire (LIF) neuron, which has a switching element with an S-type current-voltage characteristic (S-switch). The oscillator generates spikes of the S-switch in the form of chaotic pulse position modulation driven by the feedback with rate coding instability of LIF neuron. The oscillator model with piecewise function of the S-switch has resistive feedback using a second order filter. The oscillator circuit is built on four operational amplifiers and two field-effect transistors (MOSFETs) that form an S-switch based on a Schmitt trigger, an active RC filter and a matching amplifier. We investigate the bifurcation diagrams of the model and the circuit and calculate the entropy of oscillations. For the analog circuit, the “regular oscillation-chaos” transition is analysed in a series of tests initiated by a step voltage in the matching amplifier. Entropy values are used to estimate the average time for the transition of oscillations to chaos and the degree of signal correlation of the transition mode of different tests. Study results can be applied in various reservoir computing applications, for example, in choosing and configuring the LogNNet network reservoir circuits.

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19

Liu, Hong Shun, Ting Ting Lv, Ming Ming Han, Liang Zou, Li Zhang, and Qing Quan Li. "Close-Operation Overvoltage of No-Load Transmission Line with Fault Current Limiter." Applied Mechanics and Materials 672-674 (October 2014): 1373–79. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1373.

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The comprehensive impacts of series resonance type fault current limiter (FCL) on power system need further investigation and verification. With regard to switching on 500kV EHV no-load transmission line, the instantaneous peak value, the free component oscillation frequency, the fundamental component amplitude and free component amplitude of terminal overvoltage waveform are simulated with and without installation of FCL considering different switching times. The relationship curves of free component oscillation period, the fundamental component amplitude and free component amplitude are gotten respectively by simulation results. The law of the influence of different fault current limiting reactance on terminal voltage of switching on no-load line is also summarized. The analysis results show that the installation of FCL is benefit for switching on no-load line.

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20

Nakajima, Toshi, Haruka Arisawa, Ryosuke Hosaka та Hajime Mushiake. "Intended arm use influences interhemispheric correlation of β-oscillations in primate medial motor areas". Journal of Neurophysiology 118, № 5 (1 листопада 2017): 2865–83. http://dx.doi.org/10.1152/jn.00379.2016.

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To investigate the role of interhemispheric β-synchronization in the selection of motor effectors, we trained two monkeys to memorize and perform multiple two-movement sequences that included unimanual repetition and bimanual switching. We recorded local field potentials simultaneously in the bilateral supplementary motor area (SMA) and pre-SMA to examine how the β-power in both hemispheres and the interhemispheric relationship of β-oscillations depend on the prepared sequence of arm use. We found a significant ipsilateral enhancement of β-power for bimanual switching trials in the left hemisphere and an enhancement of β-power in the right SMA while preparing for unimanual repetition. Furthermore, interhemispheric synchrony in the SMA was significantly more enhanced while preparing unimanual repetition than while preparing bimanual switching. This enhancement of synchrony was detected in terms of β-phase but not in terms of modulation of β-power. Furthermore, the assessment of the interhemispheric phase difference revealed that the β-oscillation in the hemisphere contralateral to the instructed arm use significantly advanced its phase relative to that in the ipsilateral hemisphere. There was no arm use-dependent shift in phase difference in the pairwise recordings within each hemisphere. Both neurons with and without arm use-selective activity were phase-locked to the β-oscillation. These results imply that the degree of interhemispheric phase synchronization as well as phase differences and oscillatory power in the β-band may contribute to the selection of arm use depending on the behavioral conditions of sequential arm use. NEW & NOTEWORTHY We addressed interhemispheric relationships of β-oscillations during bimanual coordination. While monkeys prepared to initiate movement of the instructed arm, β-oscillations in the contralateral hemisphere showed a phase advance relative to the other hemisphere. Furthermore, the sequence of arm use influenced β-power and the degree of interhemispheric phase synchronization. Thus the dynamics of interhemispheric phases and power in β-oscillations may contribute to the specification of motor effectors in a given behavioral context.

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21

Tao, Haijun, Guopeng Zhang, Zheng Zheng, and Changshun Du. "Design of Digital Control System for DC/DC Converter of On-Board Charger." Journal of Advanced Transportation 2019 (December 24, 2019): 1–9. http://dx.doi.org/10.1155/2019/2467307.

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Vehicle charging power supply is widely used because of its small size and portability. Aiming at the problems of slow dynamic response, subharmonic, oscillation and limited soft-switching range of phase-shifted full-bridge DC/DC converter, the paper proposed a modified PSFB converter by introducing clamp diodes at the primary side of the transformer to suppress voltage oscillation of the transformer’s secondary side. Also, digital peak current phase-shifting control and slope compensation are introduced to avoid subharmonic oscillation. Dynamic dead-time control technology introduced adjust the dead-time in different load ranges through the dead-time adjustment subroutine. Finally, an experimental platform of on-board charging phase-shifted full-bridge DC/DC converter is established. The experimental results show that the power supply eliminates subharmonic oscillation, achieves a wide range of soft-switching, improves the dynamic performance and antiinterference ability of the system, and optimizes the power efficiency.

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22

Potapov, Ilya, Boris Zhurov, and Evgeny Volkov. "Multi-stable dynamics of the non-adiabatic repressilator." Journal of The Royal Society Interface 12, no. 104 (March 2015): 20141315. http://dx.doi.org/10.1098/rsif.2014.1315.

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The assumption of the fast binding of transcription factors (TFs) to promoters is a typical point in studies of synthetic genetic circuits functioning in bacteria. Although the assumption is effective for simplifying the models, it becomes questionable in the light of in vivo measurements of the times TF spends searching for its cognate DNA sites. We investigated the dynamics of the full idealized model of the paradigmatic genetic oscillator, the repressilator, using deterministic mathematical modelling and stochastic simulations. We found (using experimentally approved parameter values) that decreases in the TF binding rate changes the type of transition between steady state and oscillation. As a result, this gives rise to the hysteresis region in the parameter space, where both the steady state and the oscillation coexist. We further show that the hysteresis is persistent over a considerable range of the parameter values, but the presence of the oscillations is limited by the low rate of TF dimer degradation. Finally, the stochastic simulation of the model confirms the hysteresis with switching between the two attractors, resulting in highly skewed period distributions. Moreover, intrinsic noise stipulates trains of large-amplitude modulations around the stable steady state outside the hysteresis region, which makes the period distributions bimodal.

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23

TANAKA, HIROTO, and TOSHIMITSU USHIO. "ANALYSIS OF APERIODIC OSCILLATIONS IN A FLOW MODEL OF A SWITCHING SYSTEM." International Journal of Bifurcation and Chaos 13, no. 04 (April 2003): 981–94. http://dx.doi.org/10.1142/s0218127403007023.

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In this paper, we consider a switching system modeled by a discrete-time flow model, which has piecewise linear dynamics. In the system, it has been known that aperiodic oscillations occur. We qualitatively classify behaviors of the system into three modes, and define "blocks" consisting of the modes. We define a kind of Poincaré map by using the blocks, and show that the system has an invariant region in the Poincaré map. Moreover, we show that the Poincaré map can be reduced to a one-dimensional map. Finally, applying Lasota–Yorke's theorem to the one-dimensional map, we prove that the aperiodic oscillation is chaotic.

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24

Gwynn, Benjamin T., and Raymond de Callafon. "Demodulation of Three-Phase AC Power Transients in the Presence of Harmonic Distortion." Energies 13, no. 9 (May 8, 2020): 2341. http://dx.doi.org/10.3390/en13092341.

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Load switches in power systems may cause oscillations in active and reactive power flow. Such oscillations can be damped by synthetic inertia provided by smart inverters providing power from DC sources such as photovoltaic or battery storage. However, AC current provided by inverters is inherently non-sinusoidal, making measurements of active and reactive power subject to harmonic distortion. As a result, transient effects due to load switching can be obscured by harmonic distortion. An RLC circuit serves as a reference load. The oscillation caused by switching in the load presents as a dual-sideband suppressed-carrier signal. The carrier frequency is available via voltage data but the phase is not. Given a group of candidate signals formed from phase voltages, an algorithm based on Costas Loop that can quickly quantify the phase difference between each candidate and carrier (thus identifying the best signal for demodulation) is presented. Algorithm functionality is demonstrated in the presence of inverter-induced distortion.

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25

Yoshida, Ryo. "Self-Oscillating Gel as Smart Materials." Advances in Science and Technology 57 (September 2008): 1–4. http://dx.doi.org/10.4028/www.scientific.net/ast.57.1.

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We have developed polymer and gels with an autonomous self-oscillating function by utilizing the Belousov-Zhabotinsky (BZ) reaction. Under the coexistence of the substrates, the polymer undergoes spontaneous cyclic soluble-insoluble changes or swelling-deswelling changes (in the case of gel) without any on-off switching of external stimuli. By using microfabrication technique, ciliary motion actuator or self-walking gel have been demonstrated. Further, in order to realize nano-actuator, the linear polymer chain and the submicrometer-sized gel beads were prepared. By grafting the polymers or arraying the gel beads on the surface of substrates, we have attempted to design self-oscillating surface as nano-conveyer. For application to biomaterials, it is necessary to cause the self-oscillation under biological condition without using non-biorelated BZ substrates. So we attempted to introduce pH-control site and oxidant-supplying site into the polymer. By using the polymer, self-oscillation only in the existence of biorelated organic acid was actually achieved.

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26

Poskanzer, Kira E., and Rafael Yuste. "Astrocytes regulate cortical state switching in vivo." Proceedings of the National Academy of Sciences 113, no. 19 (April 27, 2016): E2675—E2684. http://dx.doi.org/10.1073/pnas.1520759113.

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The role of astrocytes in neuronal function has received increasing recognition, but disagreement remains about their function at the circuit level. Here we use in vivo two-photon calcium imaging of neocortical astrocytes while monitoring the activity state of the local neuronal circuit electrophysiologically and optically. We find that astrocytic calcium activity precedes spontaneous circuit shifts to the slow-oscillation–dominated state, a neocortical rhythm characterized by synchronized neuronal firing and important for sleep and memory. Further, we show that optogenetic activation of astrocytes switches the local neuronal circuit to this slow-oscillation state. Finally, using two-photon imaging of extracellular glutamate, we find that astrocytic transients in glutamate co-occur with shifts to the synchronized state and that optogenetically activated astrocytes can generate these glutamate transients. We conclude that astrocytes can indeed trigger the low-frequency state of a cortical circuit by altering extracellular glutamate, and therefore play a causal role in the control of cortical synchronizations.

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27

Liu, Wei, and Xiao Hui Ji. "Numerical Study on the Oscillation Characteristic of the Static Gas Wave Refrigerator Influenced by the Design Parameters." Advanced Materials Research 236-238 (May 2011): 1568–71. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1568.

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In order to study the relation between the design parameters and the oscillation characteristic of the static gas wave refrigerator, the oscillation characteristic influenced by the design parameters including inlet pressure, width of the nozzle and the spliter location is analysed by means of numerical study. The results show that (1)the higher the inlet pressure is, the bigger the fluidic momentum and curvature radius of the fluidic attachment are. The further the attachment location is, the higher the controlling pressure at the port of the interconnection line is, while the smaller the switching time of the fluidic is;(2)When the width of nozzle increases, the fluidic is more unstable and the switching time is shorter and attachment location is obviously further;(3)with the decrease of the spliter location, the time to oscillate becomes shorter and the switching pressure becomes smaller.

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28

Dang Nan-Nan, Zhang Zheng-Yuan, and Zhang Jia-Zhong. "Stability switching behavior of thermoacoustic oscillation in Rijke tube." Acta Physica Sinica 67, no. 13 (2018): 134301. http://dx.doi.org/10.7498/aps.67.20180269.

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29

Rosen, R., M. A. McLaughlin, and S. E. Thompson. "A NON-RADIAL OSCILLATION MODEL FOR PULSAR STATE SWITCHING." Astrophysical Journal 728, no. 1 (January 21, 2011): L19. http://dx.doi.org/10.1088/2041-8205/728/1/l19.

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30

Sei, Norihiro, Hiroshi Ogawa, and QiKa Jia. "Switching of the harmonic order in free-electron lasers by controlling the density modulation of an electron bunch." Journal of Synchrotron Radiation 25, no. 5 (August 3, 2018): 1317–22. http://dx.doi.org/10.1107/s1600577518008937.

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It was demonstrated that harmonic order in free-electron laser (FEL) oscillations could be switched by adjusting the dispersive gap of the optical klystron ETLOK-III in the storage ring NIJI-IV. The effective gains for the fundamental and third-harmonic FEL oscillations were evaluated and it was confirmed that the FEL oscillated at the order of the harmonic with the higher effective gain. The ratio between the effective gain for the fundamental and that for the third harmonic was controlled by the dispersive gap. It was also demonstrated that a spectral measurement of the FEL-based Compton scattering X-ray beam was effective for directly observing the switching of the harmonic order. These results contribute to the development of higher-harmonic FEL oscillations suppressing the fundamental FEL oscillation in the extreme ultraviolet and X-ray regions.

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31

Leroy, Jonathan, Aurelian Crunteanu, Julien Givernaud, Jean-Christophe Orlianges, Corinne Champeaux, and Pierre Blondy. "Generation of electrical self-oscillations in two-terminal switching devices based on the insulator-to-metal phase transition of VO2 thin films." International Journal of Microwave and Wireless Technologies 4, no. 1 (November 17, 2011): 101–7. http://dx.doi.org/10.1017/s175907871100095x.

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We present the non-linear electrical properties of simple two-terminal switching devices based on vanadium dioxide (VO2) thin films. The current–voltage characteristics of such devices present negative differential resistance (NDR) regions allowing generating electrical self-oscillations across the investigated devices, with frequencies ranging from several kHz up to 1 MHz. We investigate and compare the factors determining the onset of oscillatory phenomenon in both voltage- and current-activated oscillations and explain its origin. For both activation modes, we will correlate the properties of electrical oscillations (amplitude and frequency) with the amplitude of the continuous excitation signal, the physical geometry of the devices or ambient temperature. We conclude by mentioning several possible applications for the oscillation generation in the radiofrequency (RF)/microwave domains (inverters, integrated a.c. signal generators, pressure and temperature sensors, etc.).

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32

Shiraishi, M., and T. Sato. "Switching Phenomenon of a Bathtub Vortex." Journal of Applied Mechanics 61, no. 4 (December 1, 1994): 850–54. http://dx.doi.org/10.1115/1.2901567.

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Switching phenomenon of the bathtub vortex in a double-orifice water tank is experimentally investigated. This alternation between “vortexflow” and “nonvortex flow” is caused by flow rate differences through the two orifices. The oscillation frequency is experimentally examined by changing the design parameters, such as the orifice size, the distance between two orifices, and the fluid level. A linear relationship is obtained between the frequency and the flow rate difference.

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33

CHEN, WENJIE, XU YANG, and ZHAOAN WANG. "AN APPLICATION OF COMPLEX WAVELETS FOR HIGH FREQUENCY SWITCHING NOISE DETECTION." Journal of Circuits, Systems and Computers 18, no. 01 (February 2009): 97–102. http://dx.doi.org/10.1142/s0218126609004958.

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Switching signal is always composed of a series of fast voltage and current transient impulsive waves, which are created during turn-on and turn-off operation of the switching elements. This paper presents a scalogram and phase spectrum analyzing approach for the high-frequency switching noise detection. A complex Gaussian wavelet is used to extract the oscillation feature of the noise signal. The proposed scheme is more suitable in discriminating the type of switching noise than conventional wavelet transform approaches. Simulation results show the effectiveness and advantages of the method.

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34

Hayashi, Kei, Tsuyoshi Funaki, Hisato Michikoshi, and Kenji Fukuda. "1MHz Switching Operation of 1200V Full SiC Power Module." Materials Science Forum 924 (June 2018): 832–35. http://dx.doi.org/10.4028/www.scientific.net/msf.924.832.

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This paper develops 1200V, 50A full SiC half bridge power module, which embeds C snubber and gate resistors. Embedded C snubber suppresses surge voltage in fast switching operation, and gate resistors avoid gate oscillation of parallel connected SiC MOSFET in the module. 1MHz switching operation of developed module with 600V DC-link voltage is experimentally confirmed.

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35

Xue, Peng, Luca Maresca, Michele Riccio, Giovanni Breglio, and Andrea Irace. "Self-Sustained Turn-Off Oscillation of SiC MOSFETs: Origin, Instability Analysis, and Prevention." Energies 12, no. 11 (June 11, 2019): 2211. http://dx.doi.org/10.3390/en12112211.

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This paper presents a comprehensive investigation on the self-sustained oscillation of silicon carbide (SiC) MOSFETs. At first, based on the double pulse switching test, it is identified that the self-sustained oscillation of SiC MOSFETs can be triggered by two distinct test conditions. To investigate the oscillatory criteria of the two types of self-sustained oscillation, a small-signal ac model is introduced to obtain the transfer function of the oscillatory system. The instability of the oscillation is thereby determined by the two conjugate pole pairs of the transfer function. By analyzing the damping ratios of the two pole pairs, the parametric sensitivity of various circuit and device’s parameters on the two types of self-sustained oscillation are obtained. The analyses reveal the oscillatory criteria of the self-sustained oscillation for SiC MOSFETs. Based on the oscillatory criteria, necessary methods are proposed to prevent the oscillation. The proposed oscillation suppression methods are validated by the experiment at the end of the paper.

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36

Isaev, Sergey, Dmitry Nikushchenko, Alexandr Sudakov, Nikita Tryaskin, Ann Egorova, Leonid Iunakov, Alexandr Usachov, and Valery Kharchenko. "Numerical Simulation of a Periodic Quasi-Switching Mode of Flow around a Conical Dimple with a Slope Angle of 10 Degrees on the Wall of a Narrow Channel Using URANS." Fluids 6, no. 11 (October 26, 2021): 385. http://dx.doi.org/10.3390/fluids6110385.

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The applicability of the solution of the unsteady Reynolds-averaged Navier–Stokes equations (URANS) for the numerical simulation of the periodic quasi-switching regime of vortex generation and heat transfer in a deep conical dimple with a slope angle of 10∘ on the wall of a narrow channel is substantiated. To calculate the turbulent regime, the model of shear stress transfer by Menter 2003, modified taking into account the influence of the curvature of streamlines within the framework of the Rodi-Leshziner-Isaev approach, is used. At Reynolds number Re=104, the oscillation period of the transverse Rz and longitudinal forces Rx, as well as the total heat transfer Numm to the control section of the heated channel wall with a dimple, is set equal to 60, which corresponds to the Strouhal number St=0.0167. Computer visualization of swirling jet-vortex flows demonstrates focus-type sources on the side faces of the dimple. In the self-oscillating mode, a two-cell vortex system is formed with different intensities at the oscillation period Rz. Periodic changes in friction, Nusselt numbers and temperature are recorded in the longitudinal and transverse median sections of the dimple and reflect the oscillations of the vortex structure from left to right and from right to left. The formation of a fan jet is shown, which oscillates relative to the plane of longitudinal symmetry, causing a redistribution of power and thermal loads.

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37

Li, Fang, Ruixiang Hao, Haodong Lei, Xinyi Zhang, and Xiaojie You. "The Influence of Parasitic Components on LLC Resonant Converter." Energies 12, no. 22 (November 12, 2019): 4305. http://dx.doi.org/10.3390/en12224305.

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In recent years, the LLC resonant converter has been widely used in DC–DC conversion applications. However, the parasitic components of the LLC resonant converter have a significant impact in practical applications, such as influence on the conduction loss and the soft-switching of power devices, the voltage oscillation across rectifier diodes, the unregulated output voltage at light load condition and so on. It is hard to analyze the higher-order circuits by the conventional analysis methods. Focusing on the operational principle of the LLC converter with parasitic components, the differential equation model is presented and solved by the numerical method in this paper. The simulation results verify the correctness of the theoretical analysis. The causes of two different frequency oscillations and the voltage spike are clarified. The design considerations and a specific example of the LLC converter are given. The experimental results are consistent with the simulation results, and the soft-switching of primary-side switches can be achieved in the prototype.

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38

Amiranashvili, Artemij, Nikolas D. Schnellbächer, and Ulrich S. Schwarz. "Stochastic switching between multistable oscillation patterns of the Min-system." New Journal of Physics 18, no. 9 (September 27, 2016): 093049. http://dx.doi.org/10.1088/1367-2630/18/9/093049.

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39

Liu, Xinjun, Shuai Li, Sanjoy Kumar Nandi, Dinesh Kumar Venkatachalam, and Robert Glen Elliman. "Threshold switching and electrical self-oscillation in niobium oxide films." Journal of Applied Physics 120, no. 12 (September 28, 2016): 124102. http://dx.doi.org/10.1063/1.4963288.

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40

Pergament, A., G. Stefanovich, V. Malinenko, and A. Velichko. "Electrical Switching in Thin Film Structures Based on Transition Metal Oxides." Advances in Condensed Matter Physics 2015 (2015): 1–26. http://dx.doi.org/10.1155/2015/654840.

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Electrical switching, manifesting itself in the nonlinear current-voltage characteristics with S- and N-type NDR (negative differential resistance), is inherent in a variety of materials, in particular, transition metal oxides. Although this phenomenon has been known for a long time, recent suggestions to use oxide-based switching elements as neuristor synapses and relaxation-oscillation circuit components have resumed the interest in this area. In the present review, we describe the experimental facts and theoretical models, mainly on the basis of the Mott transition in vanadium dioxide as a model object, of the switching effect with special emphasis on the emerging applied potentialities for oxide electronics.

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41

Zhang, Guozheng, Guoao Zhao, Chen Li, Xinmin Li, and Xin Gu. "Smooth Switching Method for Multi-Mode Synchronous Space Vector Modulation of NPC Three-Level Inverter." World Electric Vehicle Journal 14, no. 3 (March 1, 2023): 62. http://dx.doi.org/10.3390/wevj14030062.

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To meet the requirements of output harmonic distortion of neutral point clamped (NPC) three-level inverter under low switching frequency conditions, multi-mode synchronous space vector modulation is usually adopted. When switching between different pulse patterns, there will be oscillation in the output current. This paper proposes a smooth switching method for synchronous space vector modulation. This method compensates the phase angle of the reference voltage vector, in order to make the flux trajectories continuous before and after switching. Multi-position smooth switching can be realized in the fundamental period, and there is no delay in switching. Compared with direct switching, the total harmonic distortion rate of current during switching is reduced. The calculation of the phase angle compensation value of the reference voltage vector is not affected by the specific parameters and operating conditions of the motor, and can be carried out offline. Finally, experiments are carried out on a 7.5 kW induction motor fed by NPC three level inverter to verify the feasibility and effectiveness of the proposed method.

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42

Yanagimachi, Takuya, Mafumi Hishida, Yasuhisa Yamamura, and Kazuya Saito. "Ultraslow Oscillation of Nematic Disclination after Abrupt Switching of DC Voltage." Journal of the Physical Society of Japan 84, no. 3 (March 15, 2015): 033601. http://dx.doi.org/10.7566/jpsj.84.033601.

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43

Wang, Panni, Asif I. Khan, and Shimeng Yu. "Cryogenic behavior of NbO2 based threshold switching devices as oscillation neurons." Applied Physics Letters 116, no. 16 (April 20, 2020): 162108. http://dx.doi.org/10.1063/5.0006467.

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44

Li, XiangHong, Chun Zhang, Yue Yu, and QinSheng Bi. "Periodic switching oscillation and mechanism in a periodically switched BZ reaction." Science China Technological Sciences 55, no. 10 (August 1, 2012): 2820–28. http://dx.doi.org/10.1007/s11431-012-4988-1.

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45

El Aroudi, Abdelali. "Prediction of Subharmonic Oscillation in Switching Converters Under Different Control Strategies." IEEE Transactions on Circuits and Systems II: Express Briefs 61, no. 11 (November 2014): 910–14. http://dx.doi.org/10.1109/tcsii.2011.2180097.

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46

Khaji, M., and M. R. Aghamohammadi. "Emergency transmission line switching to suppress power system inter-area oscillation." International Journal of Electrical Power & Energy Systems 87 (May 2017): 52–64. http://dx.doi.org/10.1016/j.ijepes.2016.10.011.

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47

Lu, Jing, Xiangqian Tong, Jianwu Zeng, Ming Shen, and Jun Yin. "Efficiency Optimization Design of L-LLC Resonant Bidirectional DC-DC Converter." Energies 14, no. 11 (May 27, 2021): 3123. http://dx.doi.org/10.3390/en14113123.

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The new type of L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) has merits of high efficiency, high-power density and wide gain and power ranges, and it is suitable for energy interface between energy storage systems and DC micro grid. However, the resonances are sensitive to the parasitic parameters, which will deteriorate the efficiency. This paper investigates the intrinsic mechanism of parasitic parameters on the L-LLC-BDC operating principle and working characteristics based on the analysis of working modes and resonance tank. By taking the oscillation of parasitic parameters produced in the stage for the freewheeling stage into consideration, a parameter optimization method is proposed to reduce the resonant current oscillation while maintaining the characteristic of the natural soft switching. The experiment results not only validated the proposed parameter optimization design method, but also testified to the improvement of the efficiency through the minimization of the conduction and switching loss.

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48

Xu, Qian, H. P. Du, B. He, T. H. Yan, W. H. Li, and S. S. Sun. "A Novel Reaching Law for Sliding Mode Control of Uncertain Discrete-Time Systems." Mathematical Problems in Engineering 2018 (August 15, 2018): 1–11. http://dx.doi.org/10.1155/2018/6158492.

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This paper proposed a new sliding mode control algorithm for discrete-time systems with matched uncertainty. The new control algorithm is characterized by a new discrete switching surface. Although the exponential reaching law can reduce oscillation, the control effectiveness will be suppressed when the rate of change of disturbance is high. The exponential reaching law cannot force the system states to approach sliding surface sk=0. In order to solve the contradiction between guaranteeing the basic property of quasi-sliding mode and reducing oscillation, a new discrete reaching law is proposed to improve the reaching process of discrete exponent reaching laws. The proposed method not only can force system state to approach the sliding surface sk=0 in less width of the switching manifold than existing studies, but also can alleviate chattering when the system representative points are near zero point. Simulation results are provided to validate the feasibility and reasonability of the method.

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49

Luo, Qiuyue, Christine Chevallereau, and Yannick Aoustin. "Walking Stability of a Variable Length Inverted Pendulum Controlled with Virtual Constraints." International Journal of Humanoid Robotics 16, no. 06 (December 2019): 1950040. http://dx.doi.org/10.1142/s0219843619500403.

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Bipedal walking is a complex phenomenon that is not fully understood. Simplified models make it easier to highlight the important features. Here, the variable length inverted pendulum (VLIP) model is used, which has the particularity of taking into account the vertical oscillations of the center of mass (CoM). When the desired walking gait is defined as virtual constraints, i.e., as functions of a phasing variable and not on time, for the evolution of the swing foot and the vertical oscillation of the CoM, the walk will asymptotically converge to the periodic motion under disturbance with proper choice of the virtual constraints, thus a self-stabilization is obtained. It is shown that the vertical CoM oscillation, positions of the swing foot and the choice of the switching condition play crucial roles in stability. Moreover, a PI controller of the CoM velocity along the sagittal axis is also proposed such that the walking speed of the robot can converge to another periodic motion with a different walking speed. In this way, a natural walking gait is illustrated as well as the possibility of velocity adaptation as observed in human walking.

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50

Luo, LanJiang, Haihong Liu, and Fang Yan. "Dynamic behavior of P53-Mdm2-Wip1 gene regulatory network under the influence of time delay and noise." Mathematical Biosciences and Engineering 20, no. 2 (2022): 2321–47. http://dx.doi.org/10.3934/mbe.2023109.

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<abstract><p>The tumor suppressor protein P53 can regulate the cell cycle, thereby preventing cell abnormalities. In this paper, we study the dynamic characteristics of the P53 network under the influence of time delay and noise, including stability and bifurcation. In order to study the influence of several factors on the concentration of P53, bifurcation analysis on several important parameters is conducted; the results show that the important parameters could induce P53 oscillations within an appropriate range. Then we study the stability of the system and the existing conditions of Hopf bifurcation by using Hopf bifurcation theory with time delays as the bifurcation parameter. It is found that time delay plays a key role in inducing Hopf bifurcation and regulating the period and amplitude of system oscillation. Meanwhile, the combination of time delays can not only promote the oscillation of the system but it also provides good robustness. Changing the parameter values appropriately can change the bifurcation critical point and even the stable state of the system. In addition, due to the low copy number of the molecules and the environmental fluctuations, the influence of noise on the system is also considered. Through numerical simulation, it is found that noise not only promotes system oscillation but it also induces system state switching. The above results may help us to further understand the regulation mechanism of the P53-Mdm2-Wip1 network in the cell cycle.</p></abstract>

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