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The dynamometer card is a main method to analyze downhole working conditions of the beam pumping unit in actual operation. For computer based diagnosis mode, a method based on 16-directions chain codes and K-means clustering is proposed in this paper. First, the 16-directions chain codes are used to recreate boundary contour curve of the dynamometer card; then seven feature vectors which can accurately...
With the homemade solid-core silica-based photonic crystal fiber (PCF), we observe the generation of soliton and four-wave mixing (FWM) when the femtosecond pulse is pumped at 0.822 $\mu\hbox{m} $, belonging to the normal-dispersion regime. It is generally acknowledged that FWM is unrelated to third-order dispersion, whereas we use the fourth-order Runge–Kutta method to simulate the PCF properties...
Multi-source decision is considered to be useful to make completed results. In this paper, D-S evidence theory is used to do multi-source decision fusion, and the conflict between evidences is thought to be caused by the uncertainty of mass function. In many traditional researches, evidence's own characteristics are seldom considered when fusing different mass functions. To solve this problem, the...
It is difficult to realize continuous measurement of down-hole dynamic fluid level of beam pump unit in practical oilfield production. To solve this problem, a soft senor method based on multiple LS-SVM (Least Squares Support Vector Machine) models is proposed in this paper. Many directly measurable parameters of the pumping system are selected as instrumental variables. Improved ISODATA (Iterative...
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