Rotary traveling wave oscillator... Comparison of oscillationfrequency between calculation and simulation.
... Frequency tuning range... Rotary traveling wave oscillator.
... |A4+1|versuse frequency for different Ls.
... Oscillationfrequency for two bands, i.e. when switches are on and off.
Means and standard (mean±S.E.) error of normalized percentage relative to highest power across all trials for all subjects in different configurations of stimuli. Y-axis shows average percentage relative to highest power. X-axis indicates stimulus conditions. A and b, 20–29 Hz frequencies band. No significant difference, from O2 and T6. 30–39 Hz band in c and d, occipital and parietal sites (O1, P3). 40–49 Hz band in e, site O2, compare with a and c. Above 60 Hz, in g, h, there was no significant difference,. F: inserted table showing configurations and sites yielding significant modulations. Significance levels computed relative to control, that is no shift O°. Neuman–Keuls test.
... Example of energy spectra in time-frequency analysis after averaging of single trials for one subject at temporal electrode (T6) same subject as in Fig. 5.
... Example of energy spectra in time-frequency analysis from an individual trial for one subject in temporal area T6. In this and following figures the energy values are coded on a scale of 4 to 18 μV2. (The highest energy values appear in red and they varied for each panel). Same subject as in Fig. 5.
... Frequency... Gamma oscillations... Example of energy spectra in time-frequency analysis after averaging all trials for all subjects at temporal electrode (T6). As expected notice the absence of induced gamma oscillations. Bohr effect seen at the end of each panel.
Contributors:Lorenzo Galleani, Letizia Lo Presti, Alessandro De Stefano
Analytic approximation of the fundamental frequency
... Nonlinear oscillations... Estimated and approximated fundamental frequency for the nonlinearity type C. The dotted line represents
̃0(t), the continuous line represents
... Time–frequency analysis
Ictal EEG recorded at a sampling rate of 10kHz (Patient 1). (A) Ictal EEG shown using conventional filter settings (low-pass filter 120Hz, time constant 0.1s). Only 10 channels are shown. Ictal EEG shows initial spike burst at HI1–4/HS1–4 and spike-and-waves at A5–6, followed by electrodecremental pattern and low amplitude fast activities at HI1–3/HS1. Filled circle and straight line indicate the presence of VHFO. The EEG at B, C, and D is shown using VHFO filter settings. (B and C) Preictal VHFO detected visually using low-pass filter of 3kHz and time constant of 0.001s. Preictal VHFO of 1000–2500Hz are observed at HI1 and HI2 electrodes (underlined). They appear intermittently before the start of seizures, and are interrupted by spikes. The amplitudes are 3.5–22.1μV (note the calibrations), and the durations were 12–27ms. These activities are not observed at other electrodes. HFO of 350–550Hz are seen at HS1–2 and HI1–2 electrodes, with durations of HFO of 10–14ms and the amplitudes of 22.6–234.7μV. Representative HFO peaks are marked by triangles (B). (D) VHFO recorded at HI1, HI2 (both electrodes also record preictal VHFO) and HS1 electrodes become sustained at the start of seizure. The frequencies of VHFO are 1000–2000Hz and the amplitudes are around 8.8–14.1μV. These activities superimpose on the slower rhythmic activities (70–90Hz) (marked by triangles). Sustained VHFO lasted approximately 10s. Again, these activities are not observed at other electrodes, although rhythmic activities are recorded.
... Very high frequencyoscillations
Contributors:S. Özcan, A. Toker, C. Acar, H. Kuntman, O. Çiçekoģlu
Oscillation conditions and oscillationfrequencies for proposed topologies with tracking errors
... General configuration of the CDBA based single resistance-controlled oscillator.
... Proposed CDBA based single resistance-controlled oscillators
... Voltage-controlled oscillators... Oscillation conditions and oscillationfrequencies of proposed topologies
... Calculated and experimental variations of oscillationfrequency with frequency control resistance R1 for C3=C5=1nF and C3=C5=10nF (R2=5kΩ, R6=10kΩ).
... Single resistance-controlled oscillators
Contributors:Cong Xu, Xiangda Meng
Pressure-domain signal and corresponding frequency-domain signal (a) pressure signal and (b) frequency signal.
... Performance characteristic curve insensitive to feedback fluidic oscillator configurations.
... Geometrical parameters of oscillators I, II, and III.
... Experimental results in Fig. 11 by Yang et al. , (a) fluidic oscillators and (b) plot of f versus α.
... Feedback fluidic oscillator... Fluidic oscillation... Schematic of feedback fluidic oscillators with (a) planar attachment walls (PAW), (b) step-shaped attachment walls (SAW), and (c) curved attachment walls (CAW).
Contributors:George M. Ibrahim, Simeon M. Wong, Ryan A. Anderson, Gabrielle Singh-Cadieux, Tomoyuki Akiyama, Ayako Ochi, Hiroshi Otsubo, Tohru Okanishi, Taufik A. Valiante, Elizabeth Donner, James T. Rutka, O. Carter Snead III, Sam M. Doesburg
Quantification of amplitude-to-phase cycle relationship. (A) Mean amplitudes of high frequencyoscillations, sorted by concurrent low-frequency phase into 60 bins of 0.105rad, for an example time window during a seizure; (B) an ideal cosine; and (C) a sine is modeled. (D) Phasor demonstrating the amplitude–phase cycle relationship. (E) The argument (angle) of the example phasor is a single contribution to be incremented onto a cumulative polar histogram spanning multiple subjects for one of ten given time periods in the seizure.
... Cross-frequency coupling... Modulation of high frequency amplitude by low-frequency phase. In the seizure-onset zone, significant modulation of high-frequency amplitude (40–300Hz) is observed, mainly by the phase of theta and alpha oscillations during the ictal period. In the interictal period, no specific CFC with slower oscillations is observed. There is also less cross-frequency coupling in the early propagation zone during seizures and no significant coupling is noted in the non-epileptogenic cortex. The z-axis demonstrates the modulation of amplitudes of different narrow-band frequencies (x-axis) by the phases of other narrow-band frequencies (y-axis). Lower and upper planes represent uncorrected and corrected statistical thresholds at p<0.05, respectively.
... High frequencyoscillations... Simulated data demonstrating expected polar histogram distribution. The high frequency amplitude is represented by the blue solid line, whereas the low-frequency phase is represented by the black dashed line. When the high frequency amplitude is maximal at the peak and trough of the low frequency phase, the polar histograms will indicate pi and 0, respectively.
... Individual seizure short-time Fourier transform spectrograms. The seizure onset zone contained predominantly low-frequency power, which was fairly heterogenous across the population. High frequency activity was also evident in all seizures as bursts of high power oscillatory activity.
... Topographic mapping of cross-frequency interactions in a representative subject. (A) Intraoperative image of grid demonstrating seizure onset and early propagation zones. (B) Fast-ripple amplitudes sorted by alpha phase for all grid electrodes. Cosine wave represents alpha phase from −π to π. Increased pHFO-to-low-frequency coupling occurs in the resected cortex (black borders). Values normalized by 95% confidence interval such values above 0 are significant at pfrequency modulation index for all electrodes, where the X-axis represents low frequency phase (1 to 40Hz; left to right), and the Y-axis denotes envelope amplitude (1 to 300Hz; top to bottom). Values exceeding Bonferroni correction threshold shown. Significant modulation of pHFO amplitudes by low-frequency phase is observed in the epileptogenic cortex.
... To characterize the ictal dynamics of relations between pHFO amplitude and low frequency phase, we measured the preferred slow oscillatory phase at which high amplitude pHFOs occurred at various times throughout the seizure. When the preferred phases from all bins from all subjects were plotted cumulatively on polar histograms, it was observed that pathological fast-ripple amplitudes preferentially occurred during the trough of alpha oscillations, whereas pathological ripple amplitudes preferentially occurred between 0rad and π/2rad of alpha and theta oscillatory cycles (Fig. 5; poscillations (p=0.14 and p=0.68, respectively). At seizure termination (i.e. the last bin), pHFO amplitudes occurred at the trough of the alpha oscillatory cycle (pathological ripple amplitude: p<0.01; pathological fast-ripple amplitude: p=0.03). Ripple amplitude maxima were also found at the peak of delta phase irrespective of the seizure progression (Supplementary Fig. S9). To ensure that differences in bin length did explain the measures of CFC, a reanalysis of the data with fixed length segments comprised of the first and last 2000ms of seizures, revealed the same pattern.
Contributors:N.F Thornhill, B Huang, H Zhang
An example of multiple oscillations present simultaneously (industrial tag 20).
... Oscillation analysis of pilot plant tags: (a) low frequency (b) high frequency.
... Oscillation analysis for pilot plant tags
... Oscillation analysis for industrial data
... Oscillations detected in the industrial data set. Open symbols are spurious oscillations lying on filter boundaries.
Contributors:Sang-Joon Lee, Jung-Yeop Lee
Variation of drag coefficient ratio (CD/CDo) with respect to the oscillation amplitude θA at FR=1.0.
... Schematics of the rotationally oscillating motion of a circular cylinder.
... Variation of streamwise velocity fluctuations u′ at the forcing frequency measured at a point x/d=2, y/d=0.5 with varying the oscillation amplitude θA for Re=4.14×103 and FR=1.0.
... Variation of lock-on range with respect to frequency ratio FR and oscillation amplitude θA.
... Forcing frequency... Variation of vortex shedding frequency in the high-frequency transition regime at x/d=2. (a) FR=1.3, (b) FR=1.4, (c) FR=1.6, (d) FR=1.8.
... Rotational oscillation