In this paper, we propose a fractional differential equation (FDE)-based approach for the estimation of instantaneous frequencies windowed signals as part signal reconstruction. This is based on modeling bandpass filter results around peaks equations and linking differ-integrator parameters, thereby determining long-range dependence estimated frequencies. We investigated performance proposed wi...

Improved radio frequency interference suppression method based on short time Fourier transform applied to synthetic aperture radar is proposed in this paper. The radio frequency interference, including narrow-band interference and wide-band interference, are analyzed in time frequency domain. The interference is identified at instantaneous frequency spectrum by a novel threshold criterion in ti...

The instantaneous optical frequency of an external-cavity quantum cascade laser (QCL) is characterized by comparison to a near-infrared frequency comb. Fluctuations in the instantaneous optical frequency are analyzed to determine the frequency-noise power spectral density for the external-cavity QCL both during fixed-wavelength and swept-wavelength operation. The noise performance of a near-inf...

This paper presents a novel method for the analysis of heart rate variability (HRV) during exercise stress testing enhanced with respiratory information. The instantaneous frequency and power of the low frequency (LF) and high frequency (HF) bands of the HRV are estimated by parametric decomposition of the instantaneous autocorrelation function (ACF) as a sum of damped sinusoids. The instantane...

The frequency of a sinusoidal signal is a well defined quantity. However, often in practice, signals are not truly sinusoidal, or even aggregates of sinusoidal components. Nonstationary signals in particular do not lend themselves well to decomposition into sinusoidal components. For such signals, the notion of frequency loses its effectiveness, and one needs to use a parameter which accounts f...

PURPOSE To study the perceptual consequences of changes in parameters of vocoded speech in various reverberation conditions. METHOD The 3 controlled variables were number of vocoder bands, instantaneous frequency change rate, and reverberation conditions. The effects were quantified in terms of (a) nonsense words' recognition scores for young normal-hearing listeners, (b) ease of listening ba...

This paper demonstrates methods for the online optimization of assistive robotic devices such as powered prostheses, orthoses and exoskeletons. Our algorithms estimate the value of a physiological objective in real-time (with a body "in-the-loop") and use this information to identify optimal device parameters. To handle sensor data that are noisy and dynamically delayed, we rely on a combinatio...

Inverter's performance and operating mode may be negatively affected by inverter input (dc-link) current voltage ripple. It is a common experience that even theoretically balanced loads with perfectly supply voltages, such as multiphase ac motors supplied pulse-width modulation (PWM) inverters, in practice show certain degree of unbalance, the range few percent, which introduces low-frequency i...