Based on the analysis of the current long-distance pipeline network running conditions, an economic optimal mathematical model of the gas transmission network including compressor station is used. The natural gas pipeline network is divided into different parts, and adopting the cooperation co-evolutionary genetic algorithm, the subpopulations are created. The fitness function is established by taking advantage of the punish function. The results of the simulation show that this approach has better convergence. It is an effective method to solve the optimization problem.

Periodic noise is an important manifestation of the drill string vibration signal noise. In order to extract the characteristics of the signals which reflect the situation of the tools in drilling, the periodic components which influence the original drill string vibration signal in the well field were researched and the independent component analysis algorithm which is on the basis of negative entropy for periodic vibration noise separation was adopted. At the same time, the effect of algorithm demixing was improved where periodic noise components which existed in three directions of drill string vibration signals were used, combining with the improved particle swarm optimization algorithm to seek the optimal mixed matrix by which the multi-channel mixed-signal of independent component analysis algorithm could be structured. This method in operation was fast. And after separation each signal was of high similarity. Through the experimental simulation, the method was proven effective in the drill string vibration periodic noise signal separation.