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.
This paper conducted an axial compression test on 32 group of FRP concrete composite structure with 3 kinds of section forms (FRP pipe-concrete-steel section, FRP pipe-concrete-steel pipe and hollow FRP pipe concrete). The artificial neural network was used to analysis the experimental dates. The increase of ultimate bearing capacity values was used as mechanical performance evaluation indicators. The effects of five parameters on the mechanical performance, such as the thickness of FRP pipes, the pipe diameter, the hollow ratio, the concrete strength and the steel ratio, were the emphasis of the investigation. The research results show that the most influential parameters of mechanical performance are the thickness of FRP pipes and the pipe diameter, followed by concrete strength, the difference between the three is insignificant, and the influence of hollow ratio and steel ratio are the lowest. Both the increase of the thickness and diameter of FRP pipe, The mechanical performance is significantly improved. The overall trend of ultimate bearing capacity values is decreasing with increasing the concrete strength. But under different conditions, the trend of ultimate bearing capacity values is also increasing or increased at first and then decreased, which effected by the concrete strength. With the increase of the hollow ratio and steel ratio, the overall mechanical performance decrease and the downward trend is relatively slow. The mechanical performance of small wall thickness member is decreased significant with the increase of hollow ratio. But the impact of large wall member components is not obvious. With the increase of steel ratio is significantly decreased the mechanical performance of small thickness and high concrete strength member, but the mechanical performance of big thickness and high concrete strength member is significantly increased.
A method for measuring the refractivity of saturated alcohol gas in high precision in closed vessel had been designed. This experimental apparatus used an interference method to observe the variation of interference fringes when the gas pressure changed, combining with the relationship of the number of the changing interference fringes and the refractivity of saturated alcohol gas, then the refractivity of alcohol gas under a certain pressure could be measured. The results showed that this method was accurate in deduce, simple in measurement and method, and reliable. This method could be promoted to measure the refractivity of gas. Especially, it also could be used to measure the liquid level of the liquid-storage tanks.
