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Wind turbine fault sampling algorithm based on improved BSMOTE and sequential characteristics
YANG Xian, ZHAO Jisheng, QIANG Baohua, MI Luzhong, PENG Bo, TANG Chenghua, LI Baolian
Journal of Computer Applications    2021, 41 (6): 1673-1678.   DOI: 10.11772/j.issn.1001-9081.2020091384
Abstract278)      PDF (1063KB)(456)       Save
To solve the imbalance problem of wind turbine dataset, a Borderline Synthetic Minority Oversampling Technique-Sequence (BSMOTE-Sequence) sampling algorithm was proposed. In the algorithm, when synthesizing new samples, the space and time characteristics were considered comprehensively, and the new samples were cleaned, so as to effectively reduce the generation of noise points. Firstly, the minority class samples were divided into security class samples, boundary class samples and noise class samples according to the class proportion of the nearest neighbor samples of each minority class sample. Secondly, for each boundary class sample, the minority class sample set with the closest spatial distance and time span was selected, the new samples were synthesized by linear interpolation method, and the noise class samples and the overlapping samples between classes were filtered out. Finally, Support Vector Machine (SVM), Convolutional Neural Network (CNN) and Long Short-Term Memory (LSTM) were used as the fault detection models of wind turbine gear box, and F1-Score, Area Under Curve (AUC) and G-mean were used as performance evaluation indices of the models, and the proposed algorithm was compared with other sampling algorithms on real wind turbine datasets. Experimental results show that, compared with those of the existing algorithms, the classification effect of the samples generated by BSMOTE-Sequence algorithm is better with an average increase of 3% in F1-Score, AUC and G-mean of the detection models. The proposed algorithm can be effectively applicable to the field of wind turbine fault detection where the data with sequential rule is imbalanced.
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Research and design of hadware and software fusion render layer for embedded browser
TANG Chengjian LEI Hang GUO Wensheng
Journal of Computer Applications    2013, 33 (05): 1456-1458.   DOI: 10.3724/SP.J.1087.2013.01456
Abstract884)      PDF (520KB)(595)       Save
Widely used WebKit of excellent architecture has been ported to many embedded platforms, with excellent cross-platform features. Due to the diversity of hardware for embedded platforms, WebKit open source version does not take full advantage of the characteristics of embedded platforms. Through studying WebKit render architecture, taking full advantage of the embedded hardware feature and the benefit of the software rendering design, a hardware and software fusion render layer was designed. This layer sped up the browser rendering on the embedded platform and improved the user experience. The layer was verified, the time of opening website was reduced by 48% and the speed of rendering of html animation increased by 130% compared to the original WebKit.
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Track prediction of vessel in controlled waterway based on improved Kalman filter
ZHAO Shuai-bing TANG Cheng LIANG Shan WANG De-jun
Journal of Computer Applications    2012, 32 (11): 3247-3250.   DOI: 10.3724/SP.J.1087.2012.03247
Abstract1009)      PDF (605KB)(529)       Save
Due to the lack of information of Automatic Identification System (AIS) equipment, the location of a vessel cannot be accurately judged by intelligent supporting command system based on AIS. It is difficult to accurately issue the traffic signal from it. Meanwhile, due to the narrow and winding features in controlled waterway, it is difficult for traditional Kalman filter to accurately predict track of moving vessel. In this situation, the real-time estimation of system noise in Kalman filter algorithm was proposed to increase the accuracy of track prediction of moving vessel. Simulation analysis was carried out on the tracking effect of the traditional Kalman filter and improved Kalman filter. The results indicate that the proposed algorithm can solve the lack in information of AIS equipment, and accurately predict the location of a vessel. The accuracy and the reliability of intelligence supporting command system can be ensured in controlled waterway.
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Outlier mining algorithm based on data-partitioning and grid
TANG Cheng-long XING Chang-zheng
Journal of Computer Applications    2012, 32 (08): 2193-2197.   DOI: 10.3724/SP.J.1087.2012.02193
Abstract1460)      PDF (819KB)(326)       Save
To solve the problems of inefficiency and bad-adaptability for the existing outlier mining algorithms based on grid, this paper proposed an outlier mining algorithm based on data partitioning and grid. Firstly, the technology of data partitioning was applied. Secondly, the non-outliers were filtered out by cell and the intermediate results were temporarily stored. Thirdly, the structure of the improved Cell Dimension Tree (CD-Tree) was created to maintain the spatial information of the reserved data. Afterwards, the non-outliers were filtered out by micro-cell and were operated efficiently through two optimization strategies. Finally, followed by mining by data point, the outlier set was obtained. The theoretical analysis and experimental results show that the method is feasible and effective, and has better scalability for dealing with massive and high dimensional data.
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