In Query-by-Example Spoken Term Detection (QbE-STD), the Acoustic Word Embedding (AWE) speech information extracted by Convolutional Neural Network (CNN) or Recurrent Neural Network (RNN) is limited. To better represent speech content and improve model performance, an acoustic word embedding model based on Bi-directional Long Short-Term Memory (Bi-LSTM) and convolutional-Transformer was proposed. Firstly, Bi-LSTM was utilized for extracting features, modeling speech sequences and improving the model learning ability by superposition. Secondly, to learn local information while capturing global information, CNN and Transformer encoder were connected in parallel to form convolutional-Transformer, which taking full advantages in feature extraction to aggregate more efficient information and improving the discrimination of embeddings. Under the constraint of contrast loss, the Average Precision (AP) of the proposed model reaches 94.36%, which is 1.76% higher than that of the Bi-LSTM model based on attention. The experimental results show that the proposed model can effectively improve model performance and better perform QbE-STD.
Leukocyte detection is difficult due to different shapes and degrees of staining of leukocytes during real detection process in complex scenarios. To solve the problem, a dual feature fusion CenterNet based leukocyte detection method TFF-CenterNet (Twice-Fusion-Feature CenterNet) was proposed. Firstly, the features of the backbone network were fused with the features of deconvolution layers through Feature Pyramid Network (FPN). In this way, the feature extraction ability of the method was improved to solve the problems of individual differences and different degrees of staining of leukocytes. Then, aiming at the problem of severe imbalance between the image area of leukocytes and the background image area, the heatmap loss function was improved to enhance the focus on positive samples of leukocyte and improve detection mean Average Precision (mAP). Finally, for the characteristics of the tiny target, random location, and cell adhesion of leukocyte images, coordinate attention and coordinate convolution were introduced to improve the attention and sensitivity of leukocyte location information. For leukocytes in complex scenarios, TFF-CenterNet achieves the mAP of 97.01% and the detection speed of 167 frame/s, which are 3.24 percentage points higher and 42 frame/s faster than those of CenterNet respectively. Experimental results show that the proposed method can improve the mAP of leukocyte detection in complex situations while achieving real-time requirements, and improves the robustness, so that this method can provide technical support for rapid automatic leukocyte detection in complementary medical diagnosis.
The traditional social collaborative filtering algorithms based on rating prediction have the inherent deficiency in which the prediction value does not match the real sort, and social collaborative ranking algorithms based on ranking prediction are more suitable to practical application scenarios. However, most existing social collaborative ranking algorithms focus on explicit feedback data only or implicit feedback data only, and not make full use of the information in the dataset. In order to fully exploit both the explicit and implicit scoring information of users’ social networks and recommendation objects, and to overcome the inherent deficiency of traditional social collaborative filtering algorithms based on rating prediction, a new social collaborative ranking model based on the newest xCLiMF model and TrustSVD model, namely SPR_SVD++, was proposed. In the algorithm, both the explicit and implicit information of user scoring matrix and social network matrix were exploited simultaneously and the learning to rank’s evaluation metric Expected Reciprocal Rank (ERR) was optimized. Experimental results on real datasets show that SPR_SVD++ algorithm outperforms the existing state-of-the-art algorithms TrustSVD, MERR_SVD++ and SVD++ over two different evaluation metrics Normalized Discounted Cumulative Gain (NDCG) and ERR. Due to its good performance and high expansibility, SPR_SVD++ algorithm has a good application prospect in the Internet information recommendation field.