In order to solve the problem of large interference of environmental noise during speech recognition, an isolated word recognition algorithm based on empirical mode decomposition (EMD) and dynamic time warping (DTW) is proposed. In this method, the EMD algorithm is used to decompose the speech signal with poor performance into several basic mode functions (IMF) and remove the interference and noise in the original signal. Then, based on the DTW algorithm, the short-time zero crossing rate and short-time energy are used to detect the endpoint detection of speech signal. After the speech feature parameters are extracted, the speech signal is matched with the reference template. Finally, the shortest path between the reference template and the template to be measured is used as the recognition result. The simulation results show that the proposed algorithm can improve the recognition efficiency of speech and the accuracy of recognition.
Multi-Objective Optimization Based on the Improved NSGA-Ⅱ Zlgorithm for Vinyl Chloride Rectification Process
A new improved non-dominated sorting genetic algorithm (NSGA-II) is studied aiming at solving the low purity, high energy consumption problems existed in vinyl chloride rectification process. The method can be used to solve the multi-objective optimization problem of vinyl chloride rectification process. The multi-objective optimization function with the energy consumption and purity of vinyl chlorides based on considering the various constraints of the mechanism model and the actual production conditions were established through the sensitivity analysis for the main operating parameters such as the feeding position and reflux ratio of high and low boiling tower and so on. Finally, the objective function is solved by using the improved NSGA-II. Compared to the NSGA-II, the experimental results show that the improved algorithm can get more uniform distribution of Pareto optimal solution set, which provides a strong support for the selection of parameters in the process of vinyl chloride distillation.