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Rapid progress in information and communication technologies (ICTs) has fueled the popularity of e-learning for educational purposes. However, an e-learning environment is limited in that online instructors cannot monitor immediately whether students remain focus during online autonomous learning. Therefore, this study develops a novel attention aware system (AAS) capable of recognizing students'...
Wavelet energy entropy has a small calculation amount, and it has a unique sensibility to slightly change of the dynamic system parameters. This paper presents a novel transient-based protection for power system EHV transmission line, which employ the value of wavelet energy entropy to reflect the different energy distribution between internal and external fault. The basic principle of the protection...
Strain mode is sensitivity to structure local characteristics and wavelet transform has high local property in time and frequency domain. By combining the character of strain mode and wavelet transform, strain mode is adopted as response signal to continuous wavelet analysis for damage identification. Damage location is detected by modulus maximum and damage extent is detected by Lipschitz exponent...
In this paper, we use one channel to collect the surface EMG signals of these actions separately such as elbow flexion, elbow extension, forearm supination and forearm pronation. Whereas the advantage of wavelet transform that it has fine frequency resolution at low frequencies, we can get a 4-dimension characteristic vector which is made up of 3 maximum values of detail coefficients (coefficients...
A gradient image describes the differences of neighboring pixels in the image. Extracting edges only depending on a gradient image will results in noised and broken edges. Here, we propose a two-stage edge extraction approach with contextual-filter edge detector and multiscale edge tracker to solve the problems. The edge detector detects most edges and the tracker refines the results as well as reduces...
This paper presents a new non-unit voltage protection algorithm for extra high voltage (EHV) transmission lines. This scheme is developed using wavelet analysis, in which the singularity of fault transient voltage signals in one terminal is utilized to discriminate clearly between internal and external faults. Lipschitz exponent (LE) is obtained from wavelet modulus maximum to detect singularity of...
A new ultra high-speed protection scheme is proposed in this paper. Using wavelet transform with multiresolution analysis, the current signals is decomposed into a series of detailed wavelet components. The spectral energies of the wavelet components are calculated and then employed to detect the faults. Characteristics of the proposed ultra high-speed protection algorithm are analyzed and results...
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