ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

The rational polyculture and close cultivation of multispecies freshwater fish have great practical significance in aquaculture. Aiming to identify the mixed proportions of freshwater fish, bream fish and crucian carp were taken as the research object. The passive acoustic signals of different proportions of freshwater fish were collected by hydrophone. The butter function was used for signal preprocessing. Then shorttime average energy, shorttime average zerocrossing rate, four layer wavelet packet decomposition frequency band energy, average Mel cepstrum coefficient, main peak frequency and principal peaks based on power spectrum were extracted to construct eigenvectors. The support vector machine model based on principal component analysis was used to realize the mixed proportion identification. The significant differences among the acoustic signals of freshwater fish with different mixed proportions were analyzed, and the influences of the number of principal component on the recognition rate of the model were studied. The results showed that the average Mel cepstrum coefficient had the most significant effect on the mixed proportions recognition of freshwater fish, and the effect of proportional recognition was the best by selecting the first 19 principal components. The average accuracy rate was 96.43% and Kappa coefficient was 0.96.