multi frequency vibrations of a system of two isotropic circular plates interconnected by a rolling visco-elastic layer that has nonlinear characteristics are considered. the system with two circular plates and interconnecting discrete continually distributed rolling visco nonlinear elastic rheological elements presents the model of hybrid nonlinear system. the analytical solutions of first asy...

We developed a highly integrated, Field Programmable Gate Array (FPGA)-based digital multi-frequency eddy current platform which is capable of detecting surface breaking and subsurface cracks in non-magnetic plates. Excitation signal generation, receiving signal demodulation, and USB communication were all implemented inside a Xilinx FPGA (Spartan III). Multi-frequency test results provide rich...

Frequency domain fluorescence lifetime imaging is a powerful technique that enables the observation of subtle changes in the molecular environment of a fluorescent probe. This technique works by measuring the phase delay between the optical emission and excitation of fluorophores as a function of modulation frequency. However, high-resolution measurements are time consuming, as the excitation m...

A new method for two-band approximation of excitation signals in an LPC model, to improve speech naturalness in very low rate coding, is proposed. Based on a simpli ed model of Multi-Band Excitation, the method accurately determines the degree of periodicity, using the concept of Instantaneous Frequency (IF) estimation in frequency domain. The harmonic structure in the spectrum of LPC residual,...

Abstmct The paper preknts a novel AI-ANN neural network global on-line fault detection, pa& tern classification, and relaying detection acheme for synchronous generators in interconnected electric utility networks. The input discriminant vector comprises the dominant FFT frequency spectra of eighteen input variables forming the discriminant diagnostic hyperplane. The on-line ANN based relaying ...

Optical manipulation of entanglement harnessing the frequency degree of freedom is important for encoding of quantum information. We here devise a phase-resonant excitation mechanism of an atomic interface where full control of a narrowband single-photon two-mode frequency entangled state can be efficiently achieved. We illustrate the working physical mechanism for an interface made of cold (87...

This project develops spatially selective RF excitation schemes, based on the excitation kspace principle (Pauly et al., 1987). In particular, we develop various k-space trajectories and weighting schemes, in order to excite cylindrical, spherical, and cubical volumes. The excitation pulses are inherenctly refocused, since the trajectories end at the origin of kspace. The analysis is based on a...

Introduction Parallel RF excitation using multi-element transmit coils is of interest to reduce pulse duration for spatially selective excitation. Originally, RF pulse design was formulated in the frequency domain for arbitrary k-space trajectories (Transmit-SENSE, [1]) or in the spatial domain for echo-planar trajectories [2]. Later, Transmit-SENSE was formulated in the spatial domain in [3] a...

Electrical Impedance Tomography (EIT) can perform non-invasive, low-cost, safe, fast, and simple system structure functional imaging to map the distribution changes of root zone. Multi frequency EIT solves problem that single-frequency only carry more impedance information than a given single excitation frequency. It still remains challenges simultaneously obtain multi-frequency electrical tomo...

A multi-mode harmonic transform coding (MMHTC) for speech and music signals is proposed. Its structure is organized as a linear prediction model with an input of harmonic and transform-based excitation. The proposed coder also utilizes harmonic prediction and an improved quantizer of excitation signal. To efficiently quantize the excitation of music signals, the modulated lapped transform (MLT)...