An approach of source range estimation in an ocean environment with sloping bottom is presented. The approach is based on pulse waveform correlation matching between the received and simulated signals. An acoustic pro...An approach of source range estimation in an ocean environment with sloping bottom is presented. The approach is based on pulse waveform correlation matching between the received and simulated signals. An acoustic prop- agation experiment is carried out in a slope environment. The pulse signal is received by the vertical line array, and the depth structure can be obtained. For the experimental data, the depth structures of pulse waveforms are different, which depends on the source range. For a source with unknown range, the depth structure of pulse waveform can be first obtained from the experimental data. Next, the depth structures of pulse waveforms in dif- ferent ranges are numerically calculated. After the process of correlating the experimental and simulated signals, the range corresponding to the maximum value of the correlation coefficient is the estimated source range. For the explosive sources in the experiment with two depths, the mean relative errors of range estimation are both less than 7%.展开更多
With the significant improvement of microgrid technology, microgrid has gained large-scale application.However, the existence of intermittent distributed generations, nonlinear loads and various electrical and electro...With the significant improvement of microgrid technology, microgrid has gained large-scale application.However, the existence of intermittent distributed generations, nonlinear loads and various electrical and electronic devices causes power quality problem in microgrid, especially in islanding mode. An accurate and fast disturbance detection method which is the premise of power quality control is necessary. Aiming at the end effect and the mode mixing of original Hilbert-Huang transform(HHT), an improved HHT with adaptive waveform matching extension is proposed in this paper. The innovative waveform matching extension method considers not only the depth of waveform, but also the rise time and fall time. Both simulations and field experiments have verified the correctness and validity of the improved HHT for power quality disturbance detection in microgrid.展开更多
The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniqu...The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11434012 and 41561144006
文摘An approach of source range estimation in an ocean environment with sloping bottom is presented. The approach is based on pulse waveform correlation matching between the received and simulated signals. An acoustic prop- agation experiment is carried out in a slope environment. The pulse signal is received by the vertical line array, and the depth structure can be obtained. For the experimental data, the depth structures of pulse waveforms are different, which depends on the source range. For a source with unknown range, the depth structure of pulse waveform can be first obtained from the experimental data. Next, the depth structures of pulse waveforms in dif- ferent ranges are numerically calculated. After the process of correlating the experimental and simulated signals, the range corresponding to the maximum value of the correlation coefficient is the estimated source range. For the explosive sources in the experiment with two depths, the mean relative errors of range estimation are both less than 7%.
基金supported by National High Technology Research and Development Program of China(863 Program)(No.2015AA050104)National Natural Science Foundation of China(No.51577068)
文摘With the significant improvement of microgrid technology, microgrid has gained large-scale application.However, the existence of intermittent distributed generations, nonlinear loads and various electrical and electronic devices causes power quality problem in microgrid, especially in islanding mode. An accurate and fast disturbance detection method which is the premise of power quality control is necessary. Aiming at the end effect and the mode mixing of original Hilbert-Huang transform(HHT), an improved HHT with adaptive waveform matching extension is proposed in this paper. The innovative waveform matching extension method considers not only the depth of waveform, but also the rise time and fall time. Both simulations and field experiments have verified the correctness and validity of the improved HHT for power quality disturbance detection in microgrid.
基金This work is sponsored by the Major Program in the Ninth-five Year Plan, National Natural Science Foundation of China （No.498894190 - 4）.
文摘The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.
