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To improve phase offset estimation accuracy without estimating signal's centre frequency, a cross correlation method based on Hilbert transform was proposed. Firstly, we described the principle of Hilbert transform method and correlation method respectively. Then, we proposed a cross correlation method based on Hilbert transform to calculate phase offset. Finally, comparative experiments were implemented...
Over several years of development, CNPC has become a powerful geophysical force. The company has taken an international leadership in overall onshore seismic capacity and has developed numerous unique geophysical technologies. CNPC is particularly known for developing world-leading seismic exploration technologies for application in complex mountainous areas and across Loess Tableland prospects. In...
It is an urgent problem that how to make synthesis use of various terminals such as mobile phone, PDA etc. to obtain information currently. In allusion to this problem, multi-terminal based proactive information supply system (MPISS) is put forward in this paper. Proactive service is the crucial technology. And it is the core spirit that personalization data can be shared in various terminals. The...
Smart terminal equipments, such as mobile phone, PDA etc., develop quickly at present. At the same time, there is huge information with various formats in the society, such as image, text, table etc. How to obtain information with WAP (Wireless Application Protocol) is an emergency problem nowadays. In allusion to this issue, a study on WAP self-adapt based on Web usage logs is proposed in the paper...
Ontology is a method of expressing knowledge. It is essential for multiple engineers to develop a collaborative ontology. However, current tools, techniques and methodologies for developing collaborative ontology system are inadequate. Against this background, a collaborative ontology development method based on lock-granularity is proposed in this paper. The method aims to control the lock-granularity...
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