Gamma band response to visual stimulation in humans has been observed to have both burst and resonance properties. Amplitude modulation of gamma activity at low frequencies has been seen in rat hippocampus and modeled in a number of forms. Significant amplitude modulation (p=0.05) of 33 Hz gamma frequency activity at the frequency of an 8 1/3 Hz photic driving stimulus, which also produced stro...

In this paper, we present a real-time amplitude-modulation frequency-modulation (AM-FM) analysis system, and apply the system to M-mode ultrasound video. The estimated frequency-modulation (fm) process is shown to capture the cardiac wall deformation, while the amplitude modulation process is shown to follow changes in cardiac wall material. Results from segmenting the septum and left-ventricle...

Amplitude modulation (AM) and frequency modulation (FM) in speech signals are believed to reflect various non-linear phenomena during the speech production process. In this paper, the amplitude and frequency modulation patterns are analyzed for the first three speech resonances in relation to the fundamental frequency (F0). The formant tracks are estimated, and the resonant signals are extracte...

Modulation identification is one of the most challenging steps for blind receivers. If frequency offset is present in the system, this process becomes even more difficult. The proposed method is based on the estimation of the modulation types for quadrature amplitude modulation (QAM) even before correcting the frequency offset. The modulation order is estimated using the probability density inf...

[1] Generation of ELF/VLF radio waves (300 Hz to 10 kHz) is achievable via modulation of natural currents in the lower ionosphere with high‐power HF (2–10 MHz) heating. Recently, Cohen et al. (2008b) put forth an alternative to conventional amplitude HF power modulation, therein referred to as geometric modulation, in which the HF ionospheric heating beam is geometrically steered at the desired...

To boost students' active learning and understanding of abstract scientific concepts, hands-on experiences such as experiments are necessary. Computer simulations also allow students to carry out virtually. Analog signals processed using digital signal processing because the advantages over analog processing. Numerical experiments, results, observations on band pass filtering presented. Two typ...