Abstract: A low-computation underwater acoustic wake-up method based on a multi-carrier signal is provided. A multi-carrier signal corresponding to communication nodes is constructed, absolute values of the multi-carrier signal in a window at a receiver are summed for signal arrival detection, and then frequency points of the multi-carrier signal are detected many times by using the real fast Fourier transform to realize wake-up detection. The method is suitable for accurate wake-up at any distance within a maximum communication distance of two underwater acoustic nodes, has a small amount of calculation, and is suitable for low-power single-chip microcomputers. The modem can be in a low-power sleep state for a long time.

Abstract: A well cementing method is described for improving cementing quality by controlling the hydration heat of cement slurry. By controlling the degree and/or rate of hydration heat release from cement slurry, the method improves the hydration heat release during formation of cement with curing of cement slurry, improves the binding quality between the cement and the interfaces, and in turn improves the cementing quality at the open hole section and/or the overlap section. The cementing method improves cementing quality of oil and gas wells and reduces the risk of annular pressure.

Abstract: The present application discloses is a scheduling method and system for fully autonomous waterborne inter terminal transportation, and belongs to the field of transportation. The method includes: establishing a dynamic scheduling model for waterborne Autonomous guided vessels (wAGVs); quickly inserting the dynamically arriving transportation tasks into all the existing wAGV paths, calculating the insertion cost and selecting the path and position with the lowest insertion cost to obtain updated initial paths; improving the initial path using a heuristic algorithm based on tabu search to obtain quasi-optimal wAGV paths; executing the scheduling wAGV paths.

Abstract: A low-computation underwater acoustic wake-up method based on a multi-carrier signal is provided. A multi-carrier signal corresponding to communication nodes is constructed, absolute values of the multi-carrier signal in a window at a receiver are summed for signal arrival detection, and then frequency points of the multi-carrier signal are detected many times by using the real fast Fourier transform to realize wake-up detection. The method is suitable for accurate wake-up at any distance within a maximum communication distance of two underwater acoustic nodes, has a small amount of calculation, and is suitable for low-power single-chip microcomputers. The modem can be in a low-power sleep state for a long time.

Abstract: The present application discloses is a scheduling method and system for fully autonomous waterborne inter terminal transportation, and belongs to the field of transportation. The method includes: establishing a dynamic scheduling model for waterborne Autonomous guided vessels (wAGVs); quickly inserting the dynamically arriving transportation tasks into all the existing wAGV paths, calculating the insertion cost and selecting the path and position with the lowest insertion cost to obtain updated initial paths; improving the initial path using a heuristic algorithm based on tabu search to obtain quasi-optimal wAGV paths; executing the scheduling wAGV paths. The scheduling model of the present application is based on the combinatorial optimization, and considers performance indexes such as transportation distance and customer satisfaction, and constraints such as time window and loading capacity. An initial path by using an insertion method within the framework of rolling horizon is constructed.

Abstract: A method for eliminating pump noise by empirical mode decomposition and particle swarm optimization is provided. In the method, based on a hypothesis of the pump noise being a linear combination of a group of bases, an extracted pump noise sample is decomposed into a group of signals as bases by the empirical mode decomposition. Coefficients of the optimized linear combination of the group of bases is determined by the particle swarm optimization, thus updating the pump noise sample and improving a noise elimination effect. During a limited number of noise elimination periods, a current pump noise sample is modified by weighting, such that in a limited number of iterations, the current pump noise sample gradually converges to the pump noise waveform in the unit of a varied period, so as to be applicable to a slow variation of the pump noise during a long-time operation of the system.