Papers by Keyword: Characteristic Parameter

Abstract: Through collecting real liquefaction in-situ data available worldwide, the correlations of influencing characteristics parameters such as PGA, water table depth, buried depth of sandy layer, SPT counts and shear wave velocity with respect to liquefaction were analyzed by means of Pearson correlation method. The correlative performance of the characteristic parameters with liquefaction was comparatively analyzed under conditions of varying buried depths, water tables and seismic intensities. The real correlations of the characteristic parameters with liquefaction were obtained corresponding to real dynamic loading, real buried condition and in-situ testing data. The analytical results show that water table, buried depth of sandy layer, SPT and shear wave velocity keep negative correlations with respect to liquefaction while correlation of PGA with liquefaction was positive. The correlations of buried depth of sandy layer, SPT were remarkable while the correlations of water table, shear wave velocity were weak. The correlation coefficient of SPT was the largest, followed by buried depth of sandy layer, PGA and water table; and the correlation coefficient of shear wave velocity was the smallest. The results presented herein can be used for updating the liquefaction evaluation methods in the codes.

Abstract: Making diesel engine fault diagnosis technology as the research object, we analyzed the signals mechanism of diesel engine rotating speed fluctuation, and picked up and processed it. In view of the fault mechanism, we selected the fault characteristic parameters. By simulating the diesel engine oil leak off fault, we extracted the relevant fault characteristic parameters. Fuzzy theory was applied to fault diagnosis of diesel engine, and test the effectiveness of the diagnostic method, it is concluded that the ideal diagnosis effect.

Abstract: This paper presents a framework of prototype compressor impeller auto-test system. Two type performance test can be held in a unique pipeline layout. Work conditions are accuratly under control. Status data is acquired synchronously and precisely. Performance evaluation is accomplished efficient. This framework is proved to be highly available to improve traditional manual test method.

Abstract: The article analyzes the quality checkout methods of different signals, carrying on the concrete analysis at the concrete characteristic about the signal of electromagnetic inductive communicating. Analyze the quality circumstances of waveform with the input / export signal contrast, and environmental influencing factors like power supply voltage and metal environment, transmission distance and electromagnetic environment could lead to transmit without thread fail, Get a mathematical model which can directly perceived the signal quality state with the threshold value law establishment.

Abstract: Research on Parkinson-based gait is a hotspot nowadays. However, few researches on the gait characteristics of PD patients start from the plantar pressure signal. In this paper, characteristic parameters are extracted from the gaits of PD patients and healthy people, and two-sided T inspection is performed to find significantly different parameters as input for the model classifier. The SVM classifier designed can achieve good result in discriminating the gaits of patients and normal people.

Abstract: In order to recognize the modulation type of common communication signals, an automatic recognition algorithm based on decision theory is designed and introduced. Combined with engineering realization, an adjustment is made to the algorithm. Then, a recognition scheme is proposed and realized on Digital Signal Processor (DSP), which is the key module in monitoring receiver. When the signal-to-noise ratio is not less than 12 dB, the experimental results show that the right recognition rates of eight common communication signals are above 90%. The algorithm proposed can result in a good case, and the smaller calculated complexity compared with its counterparts makes it could better reach the real-time requirement of engineering realization.

Abstract: The macroscopic traffic flow parameters characteristic is an important research content in traffic flow theory. Urban expressway plays an important role in the urban road network. It is gradually shifting from large-scale infrastructure-oriented to refinement of traffic management. With the growing of traffic demand and much more traffic congestion and accidents, integrated active traffic management should be involved in urban expressway management on the back ground of car-road coordination. As the backbone road network, traffic flow characteristic parameters have great value for the control and management of urban expressway. Then the characteristic variables of the expressway traffic flow were identified which support meticulous management for urban expressway.

Abstract: A new method for measuring and identifying characteristic parameters of moving-coil geophones is proposed in this paper, where sine sweeping signal is considered as the electric excitation instead of the traditional vibrational excitation. A mathematical model of moving-coil geophone is constructed and the frequency response of 6-parameter is obtained in this paper. Using the expression as the objective function for fitting measured amplitude-frequency curve, geophones characteristic parameters are obtained. Finally, verification test is performed and the factors affecting measure accuracy are analyzed. The experimental results indicate that the presented method is suitable for production and maintenance, especially for in-situ calibration of geophones. This work provides a new way to design and manufacture portable geophone parameter testers.

Abstract: In order to recognize the mode of analog modulation with low SNR, a recognition procedure is proposed. In this procedure, the high-order feature is used as characteristic parameter for recognition. Firstly, the characteristic parameter needs to be extracted from the signal to be recognized. Secondly, the threshold values of four modulation modes need to be calculated. At last, the characteristic parameter extracted will be compared with the four threshold values, respectively. The method and order of comparison is based on decision tree classifier. By comparison, the mode of analog modulation with low SNR can be recognized accurately.

Abstract: In this paper, according to the different maize disease images having different shape features，eight multi-fractal spectrum values were extracted as shape characteristic parameters of maize diseases, and then they were used to index on image data base. We applied learning vector quantization（LVQ）neural network to simple training，classfication and recognition. The method for recognition of maize disease can reach a higher recognition rate.