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Quadrature local oscillators... Circuit schematic of injection locked frequency dividers (ILFDs). ... Comparison of ILQVCO performance against published quadrature oscillators ... Measured phase noise at double frequency VCO and ILFDs outputs. ... Magnitude and phase of two LC tanks with a mismatch Δω between their resonant frequencies. ... Block diagram of an injection locked oscillator. ... Frequency dividers
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Frequency domain analysis in CAD ... Frequency domain analysis in ischemic stroke ... low frequency oscillations
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(A) The reduction in the frequency of the oscillations as a function of thiopental concentration. (B) The reduction in the frequency of the oscillations as a function of propofol concentration. (C) The reduction in the frequency of the oscillations as a function of ketamine concentration. Each point represents the mean of data from an average of 6 slices and the error bars are standard errors. The lines are least squares regressions. The data have been normalised such that the control frequency in the absence of anaesthetic is unity. The frequency (mean ± s.e.m) of the control response was 36.0 ± 0.1 Hz (n = 11) for the thiopental data, 38.0 ± 0.7 Hz (n = 21) for the propofol data and 33.8 ± 0.7 Hz (n = 38) for the ketamine data. ... 40 Hz oscillations... The effect of the optical isomers of etomidate on the oscillations. Each point represents the mean of data from an average of 5 slices and the error bars are standard errors. The inactive S(−)-enantiomer had no significant effect on the oscillation frequency at concentrations up to 2.5 μM. The lines have been drawn by eye and have no theoretical significance. The data have been normalised such that the control frequency in the absence of anaesthetic is unity. The frequency (mean ± s.e.m) of the control response was 38.9 ± 0.6 Hz (n = 54). ... (A) Representative traces from the same brain slice showing control oscillations (upper trace), oscillations in the presence of 1.4 vol% isoflurane (middle trace) and oscillations after washout of isoflurane (lower trace). (B) Power spectra of data from the same slice as in (A) showing the reduction in frequency in the presence of 1.4 vol% isoflurane. ... (A) Representative traces from the same brain slice showing control oscillations at 26 and 30 °C. (B) Power spectra of data from the same slice as in (A) showing the reduction in oscillation frequency at 26 °C compared to 30 °C. (C) Plot of oscillation frequency as a function of temperature. The line is a least squares regression. The data were recorded from 4 slices. ... Percentage change in carbachol-evoked gamma oscillation frequency and prolongation of IPSC time-course at clinical concentrations of anaesthetic
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Generic level schemes of atoms for optical qubits (left) and radio-frequency qubits (right). In addition to the two qubit levels {|0〉,|1〉} usually a third rapidly decaying level is used for laser cooling and state read-out. While the optical qubit is typically manipulated on a quadrupole transition, radio-frequency qubit levels are connected with Raman-transitions. ... Rabi oscillations of a single Ca+ ion. Each dot represents 1000 experiments, each consisting of initialization, application of laser light on the qubit transition and state detection. ... Normal modes of a three-ion crystal along the axial direction with motional frequencies ωi. ... Energy level scheme of a single trapped ion with a ground (|g〉) and an excited (|e〉) level in a harmonic trap (oscillator states are labeled |0〉,|1〉,|2〉,…). Ω denotes the carrier Rabi frequency. The Rabi frequency on the blue sideband transition |0,e〉↔|1,g〉 transition is reduced by the Lamb-Dicke factor η as compared to the carrier transition (see Eq. (5)). The symbols ωqubit and ωt denote the qubit and the trap frequency, respectively. ... Rabi oscillation on the blue sideband of the center-of-mass mode. The data were taken on a string of two 40Ca+ ions whose center-of-mass mode was cooled to the ground state. Only one of the ions was addressed. The population oscillates between the |S,0〉 and the |D,1〉 state of the addressed ion.
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Radius and mean surface density for spherical fullerenes and the corresponding CNT radius for stable oscillations [33,34]. ... Oscillation frequency of C60-nanotube oscillator versus half length of nanotube. ... Oscillation frequency... Oscillation frequency against the initial velocity of fullerene (L=70Å). ... Oscillation frequency against the initial velocity of fullerene (RF=3.55Å). ... Variation of frequency with the difference between the amplitude and half length of nanotube (L=70Å).
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Entrainment of spontaneous oscillation by an external stimulus. (A) Sinusoidal forces were applied to a spontaneously oscillating hair cell bundle for three different stimulation conditions: one at the frequency of the spontaneous oscillations (FO=4kHz) and two for slightly lower frequency (3.5kHz). Thick lines are bundle tip displacements and thin red lines are external stimuli. Initial states of the bundle for the three simulations were the same and selected to have the opposite phase to the stimulus. (B) Bundle displacement in response to the three different stimuli in (A) averaged over 160 presentations (top two records) and 80 presentations (bottom record). Note that the response at FO (4kHz, top) builds up with a time constant of 0.7ms, indicative of a sharply tuned resonator. The bundle entrained poorly to the 3.5kHz stimulus at low level (middle), but at the higher level the force was sufficient to suppress the spontaneous movement and the bundle movement was entrained to the external stimulus. (C) A single cycle of bundle displacement (red line) averaged over 200ms of response compared to the force stimulus (black line), which was scaled for comparison with displacements. The bundle compliance obtained by dividing the displacement amplitude by the force amplitude is given beside each trace. (D) PSD plots for each response showing a sharply tuned response at FO (top). At 3.5kHz, the spectral density contains frequency components (both the spontaneous oscillation and the stimulus; middle). For the larger stimulus level at 3.5kHz, the spectral density is now dominated by the stimulus frequency. ... Effects of Ca2+ on the spontaneous oscillation. Different levels of the calcium concentration at the fast adaptation site were simulated. The bundle oscillated when the Ca2+ concentration at the fast adaptation site was between 12 and 30μM. Other parameters were identical to those given in Table 1. The hair bundle oscillated most strongly at 4kHz with Ca2+ of 20μM. The oscillation frequency increased from 3kHz to 4.5kHz as the Ca2+ concentration increased from 12 to 30μM. Note the “twitch-like” behavior at low Ca2+. ... Compressive nonlinearity demonstrated by entrainment to an external stimulus. The hair cell bundle was stimulated with sinusoidal forces with different frequencies (1–16kHz) and magnitudes (0.1–1000 pN). (A) Representative examples of average bundle tip displacements (solid lines) and force stimuli (broken lines) scaled for comparison with displacements for one stimulus cycle. Displacements were averaged cycle by cycle over 200ms of response. (B) Bundle displacement plotted against stimulation frequency for three different force magnitudes. Note the sharp tuning for small 1 pN stimuli and the broad tuning for the largest 100 pN stimuli. (C) Bundle displacement plotted against force magnitude at the frequency of the spontaneous oscillations, FO=4kHz. Note that the relationship displays a compressive nonlinearity for intermediate stimulus levels, is linear at low stimulus levels, and again approaches linearity (denoted by dashed line) at the highest levels. (D) Gain plotted against stimulation frequency for three different force magnitudes. Gain is defined as the ratio of the compliance under the stimulus conditions to the passive compliance with the MT channel blocked. (E) Gain plotted against force magnitude at the frequency of the spontaneous oscillations, FO=4kHz. The gain declines from a maximum of 50 at the lowest levels, approaching 1 (passive) at the highest levels. ... Determinant of frequency: KD, Ca2+ dissociation constant. (A) The hair bundle morphology of a rat high-frequency hair cell was used to create a new FE model. The hair bundle had more stereocilia of smaller maximum height, (2.4μm compared to 4.2μm) than the low-frequency bundle. (B) Spontaneous oscillations of bundle position and open probability. (C) PSD plots indicating sharply tuned oscillations at 23kHz. For these simulations, KD and CFA, the Ca2+ concentration near the open channel, were elevated five times. Other values as in Table 1 except: fCa=8 pN and f0, the intrinsic force difference between open and closed states=−15 pN. ... Effects of loading the hair bundle with a tectorial membrane mass. (A) Passive resonance of a low-frequency (solid circles) and a high-frequency (open circles) hair bundle in the absence of the tectorial membrane mass with MT channels blocked. The system behaves as a low-pass filter with corner frequency of 23kHz (solid circles) and 88kHz (open circles). The hair bundle was driven with a sinusoidal force stimulus of 100 pN amplitude at different frequencies. (B) Passive behavior of the same two hair bundles surmounted by a block of tectorial membrane. The block of tectorial membrane had a mass of 6.2×10−12 kg for the low-frequency location, which was decreased fourfold for the high-frequency location. The MT channels were blocked, so the system was not spontaneously active. Resonant frequencies: 5.1kHz (solid circles) and 21kHz (open circles). (C). The active hair bundles, incorporating MT channel gating, combined with the tectorial membrane mass generated narrow-band spontaneous oscillations. PSD function is plotted against frequency, giving FO=2.9kHz, Q=40 for the low-frequency location, and FO=14kHz, Q =110 for the high-frequency location.
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Amplitude spectra of our entire data sets for HD 101065 acquired on HJD 2456460 – 6462. Panel (a) clearly shows the principal frequency of oscillation ν1=1.372867 mHz, and the secondary frequency ν2=0.954261 mHz. On pre-whitening ν1, we are left with ν2 in panel (b). Panel (c) gives the residuals after pre-whitening ν2. There is still evidence of further frequencies although below the detection criterion. ... Amplitude spectra of HD 101065 data acquired on HJD 2456460 – 6462. Panel (a) clearly shows the principal frequency of oscillation ν1=1.372867 mHz, and the secondary frequency ν2=0.954261 mHz. On pre-whitening ν1, we are left with ν2 in panel (b). Again, on pre-whitening ν2, we are left with low frequency residuals peaks in panel (c) which still suggests possible presence of further oscillation frequencies. ... The Non-linear least-square fit for the principal frequency ν1=1.372865 mHz. The JohnsonB amplitude of oscillation from year 1978 – 1988 were adopted from Martinez and Kurtz (1990), while that of year 2013 represent the amplitude and phase of oscillation secured from our combined data set (HJD 2456404 – 6462). Apart from year 2013 observation which has been analysed using 40-s integrations, 80-s integrations were used in all earlier observations adopted from Martinez and Kurtz (1990)). ... Stars: oscillations... The corresponding nightly amplitude spectra of HD 101065 on HJD 2456404 – 6462. Note the presence of resolved secondary frequencies ν2 in each panel around the region of 1 mHz. The known principal oscillation frequency ν1 is also present in all the panels, while 2ν1 which is the harmonic of ν1 appears marginally in panel (b) only. ... Non-linear least-square fit for the frequencies secured from our combined data set (HJD 2456404 – 6462).
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(a) Time-averaged drag coefficients, (b) r.m.s. of drag coefficients, and (c) r.m.s. of lift coefficients as a function of frequency ratio and distance between two cylinders. ... Instantaneous vorticity contours of two oscillating cylinders at Re=160, go=2, Ae=0.2, and fe/fo**=1.0. (a) present result, (b) results from Mahir and Rockwell (1996). ... Peak values of Fourier transforms of lift coefficients of two oscillating cylinders ... Drag and lift coefficients as a function of time for one oscillating. ... Wake patterns of two oscillating cylinders ... Forced oscillation
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The relation between seizure frequency per month and number of channels with (A) ripples (>1/min), (B) fast ripples (>1/min), and (C) more than 20 fast ripples per minute. There were no patients with 0 channels with ripples (>1/min; A), but there were patients with 0 channels with fast ripples (>1 or >20/min; B and C). The seizure frequency was shown on a logarithmic scale, because of the distribution. As indicated in the text, there was no correlation between seizure frequency per month and the number of channels with more than 1 ripple or fast ripple per minute, but there was a positive correlation between seizure frequency and more than 20 fast ripples per minute. ... This table shows the correlation coefficients Rho for different alternative comparisons: seizure frequency (seizures/month) compared to the number and percentage of channels with ripples, fast ripples, spikes and ripples and fast ripples without spikes (first two lines), seizure frequency compared to number of channels with higher rates of ripples and fast ripples (>5, >10 and >20, lines 3–5) and number of seizure-days/month compared to channels with ripples and fast ripples. All comparisons were done for all patients, all patients with temporal lobe epilepsy and all patients with unilateral mesiotemporal seizure onset.
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(Color online) Same as in Fig. 6 (i.e. LZS interferometry with low-frequency driving), but including the effects of decoherence. The time averaged upper level occupation probability P+¯ was obtained numerically from the Bloch equations with the Hamiltonian (1). The dephasing time T2 is given by ωT2/(2π)=0.1 in (a), 1 in (b), 5 in (c) and T2=2T1 in (d). The relaxation time is given by ωT1/(2π)=10. ... (Color online) Same as in Fig. 7 (i.e. LZS interferometry with high-frequency driving), but including the effects of decoherence. The time-averaged upper diabatic state occupation probability P¯up is obtained numerically by solving the Bloch equations with the Hamiltonian (1). The dephasing time T2 is given by ωT2/(2π)=0.1 in (a), 0.5 in (b), 1 in (c) and T2=2T1 in (d). The relaxation time is given by ωT1/(2π)=103. ... Superconducting qubits... Stückelberg oscillations... (Color online) (a) Energy levels E versus the bias ε. The two solid curves (red and blue) represent the adiabatic energy levels, E±, which display avoided crossing with energy splitting Δ. The dashed lines show the crossing diabatic energy levels E↑,↓, corresponding to the diabatic states φ↑ and φ↓. (b) The bias ε represents the driving signal, and it oscillates between εmin=ε0−A and εmax=ε0+A with a sinusoidal time dependence: ε(t)=ε0+Asinωt. ... Parameters used in different experiments studying LZS interferometry: tunneling amplitude Δ, maximal driving amplitude Amax, and driving frequency ω in the units GHz×2π, minimal adiabaticity parameter δmin=Δ2/(4ωAmax), and maximal LZ probability PLZmax=exp(−2πδmin).
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