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Deep neural network compression algorithm based on hybrid mechanism
Xujian ZHAO, Hanglin LI
Journal of Computer Applications    2023, 43 (9): 2686-2691.   DOI: 10.11772/j.issn.1001-9081.2022091392
Abstract234)   HTML13)    PDF (2917KB)(198)       Save

With the rapid development of Artificial Intelligence (AI) in recent years, the demand for Deep Neural Network (DNN) from devices with limited resources such as embedded devices and mobile devices has increased sharply. The problem of how to compress neural networks without affecting the effect of DNNs has great theoretical and practical significance, and is a hot research topic in deep learning now. Firstly, aiming at the problem that DNN is difficult to be ported to resource-limited devices such as mobile devices due to their large models and large computational cost, the experimental performance of existing DNN compression algorithms in terms of memory usage, running speed, and compression effect was deeply analyzed, so that the influence factors of the DNN compression algorithm were explored. Then, the knowledge transfer structure composed of student network and teacher network was designed, the knowledge distillation, structural design, network pruning, and parameter quantization mechanisms were fused together, and a DNN optimization and compression model based on hybrid mechanism was proposed. Experimental comparison and analysis were conducted on mini-ImageNet dataset using AlexNet as the Benchmark. Experimental results show that the capacity of compressed AlexNet is reduced by 98.5% with 6.3% loss of accuracy, which verify the effectiveness of the proposed algorithm.

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Multi-similarity K-nearest neighbor classification algorithm with ordered pairs of normalized real numbers
Haoyang CUI, Hui ZHANG, Lei ZHOU, Chunming YANG, Bo LI, Xujian ZHAO
Journal of Computer Applications    2023, 43 (9): 2673-2678.   DOI: 10.11772/j.issn.1001-9081.2022091376
Abstract254)   HTML12)    PDF (1618KB)(121)       Save

For the problems that the performance of the nearest neighbor classification algorithm is greatly affected by the adopted similarity or distance measuring method, and it is difficult to select the optimal similarity or distance measuring method, with multi-similarity method adopted, a K-Nearest Neighbor algorithm with Ordered Pairs of Normalized real numbers (OPNs-KNN) was proposed. Firstly, the new mathematical theory of Ordered Pair of Normalized real numbers (OPN) was introduced in machine learning. And all the samples in the training and test sets were converted into OPNs by multiple similarity or distance measuring methods, so that different similarity information was included in each OPN. Then, the improved nearest neighbor algorithm was used to classify the OPNs, so that different similarity or distance measuring methods were able to be mixed and complemented to improve the classification performance. Experimental results show that compared with 6 improved nearest neighbor classification algorithms, such as distance-Weighted K-Nearest-Neighbor rule (WKNN) rule on Iris, seeds, and other datasets, OPNs-KNN has the classification accuracy improved by 0.29 to 15.28 percentage points, which proves that the performance of classification can be improved greatly by the proposed algorithm.

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Key event extraction method from microblog by integrating social influence and temporal distribution
Xujian ZHAO, Chongwei WANG, Junli WANG
Journal of Computer Applications    2022, 42 (9): 2667-2673.   DOI: 10.11772/j.issn.1001-9081.2021071330
Abstract283)   HTML14)    PDF (2009KB)(187)       Save

Aiming at the problem that the existing microblog event extraction methods are based on the content characteristics of events and ignore the relationship between the social attributes and time characteristics of events, so that they cannot identify the key events in the propagation process of microblog hot spots, a key event extraction method from microblog by integrating social influence and temporal distribution was proposed. Firstly, the social influence was modeled to present importance of microblog events. Secondly, the temporal characteristics of microblog events during evolution were considered to capture the differences of events under different temporal distributions. Finally, the key microblog events were extracted under different temporal distributions. Experimental results on real datasets show that the proposed method can effectively extract key events in microblog hot spots. Compared with four methods of random selection, Term Frequency-Inverse Document Frequency (TF-IDF), minimum-weight connected dominating set and degree and clustering coefficient information, the proposed method has the event set integrity index improved by 21%, 18%, 26% and 30% on dataset 1 respectively, and 14%, 2%, 21% and 23% on dataset 2 respectively. The extraction effect of the proposed method is better than those of the traditional methods.

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Storyline extraction method from Weibo news based on graph convolutional network
Xujian ZHAO, Chongwei WANG
Journal of Computer Applications    2021, 41 (11): 3139-3144.   DOI: 10.11772/j.issn.1001-9081.2021030451
Abstract427)   HTML36)    PDF (860KB)(328)       Save

As a key platform for people to acquire and disseminate news events, Weibo hides rich event information. Extracting storylines from Weibo data provides users with an intuitive way to accurately understand event evolution. However, the data sparseness and lack of context make it difficult to extract storylines from Weibo data. Therefore, two consecutive tasks for extracting storylines automatically from Weibo data were introduced: 1) events were modeled by propagation impact of Weibo, and the primary events were extracted; 2) the heterogeneous event graph was built based on the event features, and an Event Graph Convolution Network (E-GCN) model was proposed to improve the learning ability of implicit relations between events, so as to predict story branches of the events and link the events. The proposed method was evaluated from the perspectives of story branch and storyline on real datasets. In story branch generation evaluation, the results show that compared with Bayesian model, Steiner tree and Story forest, the proposed method has the F1 value higher by 28 percentage points, 20 percentage points and 27 percentage points on Dataset1 respectively, and higher by 19 percentage points, 12 percentage points and 22 percentage points on Dataset2 respectively. In storyline extraction evaluation, the results show that compared with Story timeline, Steiner tree and Story forest, the proposed method has the correct edge accuracy higher by 33 percentage points, 23 percentage points and 17 percentage points on Dataset1 respectively, and higher by 12 percentage points, 3 percentage points and 9 percentage points on Dataset2 respectively.

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Digital camouflage generation method based on cycle-consistent adversarial network
Xu TENG, Hui ZHANG, Chunming YANG, Xujian ZHAO, Bo LI
Journal of Computer Applications    2020, 40 (2): 566-570.   DOI: 10.11772/j.issn.1001-9081.2019091625
Abstract608)   HTML9)    PDF (5080KB)(432)       Save

Traditional methods of generating digital camouflages cannot generate digital camouflages based on the background information in real time. In order to cope with this problem, a digital camouflage generation method based on cycle-consistent adversarial network was proposed. Firstly, the image features were extracted by using densely connected convolutional network, and the learned digital camouflage features were mapped into the background image. Secondly, the color retention loss was added to improve the quality of generated digital camouflages, ensuring that the generated digital camouflages were consistent with the surrounding background colors. Finally, a self-normalized neural network was added to the discriminator to improve the robustness of the model against noise. For the lack of objective evaluation criteria for digital camouflages, the edge detection algorithm and the Structural SIMilarity (SSIM) algorithm were used to evaluate the camouflage effects of the generated digital camouflages. Experimental results show that the SSIM score of the digital camouflage generated by the proposed method on the self-made datasets is reduced by more than 30% compared with the existing algorithms, verifying the effectiveness of the proposed method in the digital camouflage generation task.

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