Combined spectral and speech features for pig speech recognition.

The sound of the pig is one of its important signs, which can reflect various states such as hunger, pain or emotional state, and directly indicates the growth and health status of the pig. Existing speech recognition methods usually start with spectral features. The use of spectrograms to achieve classification of different speech sounds, while working well, may not be the best approach for solving such tasks with single-dimensional feature input. Based on the above assumptions, in order to more accurately grasp the situation of pigs and take timely measures to ensure the health status of pigs, this paper proposes a pig sound classification method based on the dual role of signal spectrum and speech. Spectrograms can visualize information about the characteristics of the sound under different time periods. The audio data are introduced, and the spectrogram features of the model input as well as the audio time-domain features are complemented with each other and passed into a pre-designed parallel network structure. The network model with the best results and the classifier were selected for combination. An accuracy of 93.39% was achieved on the pig speech classification task, while the AUC also reached 0.99163, demonstrating the superiority of the method. This study contributes to the direction of computer vision and acoustics by recognizing the sound of pigs. In addition, a total of 4,000 pig sound datasets in four categories are established in this paper to provide a research basis for later research scholars.

Realization of low-cross-talk half-wavelength pitch waveguide array on a silicon-on-insulator platform.

Realizing a densely packed waveguide antenna array is of great importance in light detection and ranging (LIDAR), owing to its suppressed grating lobes. In this work, a low-cross-talk half-wavelength pitch silicon waveguide array is proposed and experimentally demonstrated. It has a periodic arrangement of silicon strip nanophotonic waveguides, between which deep-subwavelength silicon strips are placed. Our experimental results show that this array's cross talk suppression is nearly 20 dB and has a bandwidth covering a wavelength range from 1500 nm to 1560 nm. Our realization of a half-wavelength pitch waveguide array may offer a promising platform for studying integrated optical phased arrays for solid-state LIDAR with a very low grating lobe and thus potentially a large field of view.