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Multiple fault diagnosis of down-hole conditions of sucker-rod pumping wells based on Freeman chain code and DCA 被引量:13
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作者 LI Kun GAO Xian-wen +2 位作者 YANG Wei-bing DAI Ying-long TIAN Zhong-da 《Petroleum Science》 SCIE CAS CSCD 2013年第3期347-360,共14页
It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production sche... It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis (DCA) is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions. 展开更多
关键词 Sucker-rod pumping wells multiple faults designated component analysis control chart freeman chain code dynamometer card
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A code-based approach for labeling in complex irregular regions
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作者 Zhi-long LI Jun-jie CAO +1 位作者 Xiu-ping LIU Zhi-xun SU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第10期1450-1460,共11页
Labeling information in a complex irregular region is a useful procedure occurring frequently in sheet metal and the furniture industry which will be beneficial in parts management.A fast code-based labeler(FCBL) is p... Labeling information in a complex irregular region is a useful procedure occurring frequently in sheet metal and the furniture industry which will be beneficial in parts management.A fast code-based labeler(FCBL) is proposed to accomplish this objective in this paper.The region is first discretized,and then encoded by the Freeman encoding technique for providing the 2D regional information by 1D codes with redundancies omitted.We enhance the encoding scheme to make it more suitable for our complex problem.Based on the codes,searching algorithms are designed and can be extended with customized constraints.In addition,by introducing a smart optimal direction estimation,the labeling speed and accuracy of FCBL are significantly improved.Experiments with a large range of real data gained from industrial factories demonstrate the stability and millisecond-level speed of FCBL.The proposed method has been integrated into a shipbuilding CAD system,and plays a very important role in ship parts labeling process. 展开更多
关键词 LABELING freeman codes Region filling Optimal direction SHIPBUILDING
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