Publications (2)0 Total impact
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ABSTRACT: The power quality disturbances and the resulting problems have emerged as an important research. The power system industries with sensitive electrical loads have become more dependent on the quality of power supply system. The power quality disturbances analysis is becoming an essential issue because of the widespread use of electronic nonlinear loads that have affected the operation of distributed power system network in residential and industrial areas. A novel approach to detect and locate short duration disturbance in distributed power system combing neural network is presented. The paper tries to explain to investigate feature extraction of transient signal and to analyze the disturbance signal. The feature information obtained from wavelet decomposition coefficients acts as input vector of wavelet network for power quality disturbance pattern recognition. The power quality disturbance recognition performance is completed and the improved back-propagation algorithm is used to fulfill the network parameter initialization. By means of simulation data training, the disturbance pattern can be obtained from the trained wavelet network output. The simulation results and analysis indicate that the wavelet transform combining with neural network is sensitive to transient signal singularity detection.
Conference Paper: Information processing in digital holographic imaging and measurement[Show abstract] [Hide abstract]
ABSTRACT: According to Fresnel diffraction theory, the principles of imaging and shape measurement are analyzed concisely. The model of phase aberration in numerical reconstruction is built. The zero-order diffraction and unwanted first-order image can be removed by using frequency filtering. Based on lensless Fourier transform digital holographic setup, the experiment is conducted by using a US Air Force test target as microscopic object. The accurate phase image is obtained by combining the automatic procedure for phase aberration compensation with manual adjustment of reconstructing parameters. The lateral resolution of the intensity image of 3.10mum without any pre-magnification is demonstrated experimentally, and higher resolution of phase image has been achieved. The results show that in the case of strong noise, the inexact reconstruction parameters can be gained only by the automatic procedure. In order to obtain the accurate phase information, the finer manual adjustment is necessary subsequently. It is the committed step that recording high quality digital hologram in digital holography.
Hebei University of EngineeringHan-tan-shih, Hebei, China