This paper puts forward a kind of gearbox fault diagnosis methods which based on empirical mode decomposition (EMD), Hilbert transform, Fast Fourier Transform (FFT) and spectrum refined techniques. This method is applicable to the analysis of the nonlinear unsteady signal. First of all used wavelet denoising to the acquisition of gearbox vibrate signal, again carries on the empirical mode decomposition (EMD), than get a certain number of intrinsic mode function (imf); Choose the specific imf, based on kurtosis value, after the Hilbert transform and Fast Fourier Transform is done, the corresponding power spectrum can be obtained; To refine the power spectrum and extract the gearbox fault characteristic frequency; Then in pattern recognition and diagnosis of the gearbox fault, and compared with the normal signal characteristics. The analysis results show that the proposed method can effectively detect the gearbox fault characteristics.
The paper briefly introduces the function and characteristics of the ground simulation software CDEGS, and computes the grounding grid model by using the MALZ module. The grounding grid GPR (Ground Potential Rise) and the percentage of reference power bus GPR are analyzed after the exciting current source injected into the grounding grid, and compared and analyzed with CDEGS softwares simulation calculation results, it is easy to diagnose defect and locate defect position in the grounding grid.
Through the visual inspection, the appearance of size measurement, crimping size measurement, the steel core crimping length measurement and steel core tensile strength test of tension crimp barrel on 220kV transmission line. Made a detail analysis on test results combined with wire crimping theory. Pointed out the wire crimping defects caused by crimping irregularities. Analyzed the main causes of rupture accident, and made recommendations for improvement. Provides a reference to wire crimp and wire accident analysis.
For gearbox common type of fault, leads to common methods gear fault diagnosis, according to the various parameters of the gearbox, to give a gearbox fault frequencies. Using mat lab signal analysis, by the time domain analysis, frequency domain analysis, cestrum analysis, signal processing methods envelope spectrum consolidated results there is a fault in the gearbox countershaft. This papers they have certain significance to gear fault diagnosis.
In order to grasp the related information and parameters needed by the tree growth, and management, establish the authentic decision-making model of tree growth management using the effective resource information, the resource information of tree growth management are investigated from the perspective of ontology and knowledge base technology. The paper introduces the ontology and knowledge base technology, adopts the knowledge organizing pattern based on ontology, studies the structure and technique of knowledge of tree growth management, the ontology is regarded as the knowledge organizing pattern to establish the open knowledge base of tree growth management, and constructs the management model of tree growth. Practice has proved that the research and application of ontology in the resource information of tree growth management has important value for the model construction of tree growth management, achieves the sharing of resource information of tree growth management.
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