375 research outputs found

    Feature Extraction Method for Ship-Radiated Noise Based on Extreme-point Symmetric Mode Decomposition and Dispersion Entropy

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    175-183A novel feature extraction method for ship-radiated noise based on extreme-point symmetric mode decomposition (ESMD) and dispersion entropy (DE) is proposed in the present study. Firstly, ship-radiated noise signals were decomposed into a set of band-limited intrinsic mode functions (IMFs) by ESMD. Then, the correlation coefficient (CC) between each IMF and the original signal were calculated. Finally, the IMF with highest CC was selected to calculate DE as the feature vector. Comparing DE of the IMF with highest CC by empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and ESMD, it is revealed that the proposed method can assist the feature extraction and classification recognition for ship-radiated noise

    Feature Extraction Method for Ship-Radiated Noise Based on Extreme-point Symmetric Mode Decomposition and Dispersion Entropy

    Get PDF
    175-183A novel feature extraction method for ship-radiated noise based on extreme-point symmetric mode decomposition (ESMD) and dispersion entropy (DE) is proposed in the present study. Firstly, ship-radiated noise signals were decomposed into a set of band-limited intrinsic mode functions (IMFs) by ESMD. Then, the correlation coefficient (CC) between each IMF and the original signal were calculated. Finally, the IMF with highest CC was selected to calculate DE as the feature vector. Comparing DE of the IMF with highest CC by empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and ESMD, it is revealed that the proposed method can assist the feature extraction and classification recognition for ship-radiated noise

    A new method for detecting line spectrum of ship-radiated noise based on a new double duffing oscillator differential system

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    34-43In order to detect line spectrum of ship-radiated noise under the ocean background noise and improve the method of detecting duffing oscillator intermittent chaos, a method of detecting intermittent chaos based on variable step size dual duffing oscillator differential system is proposed. Based on the duffing oscillator, two independent and incompletely coupled duffing oscillators can be differentiated based on the differential principle by using the proposed method, which reduces the computational complexity and makes the timing diagram more intuitive. In order to further improve the detection efficiency and reduce the computational complexity of the system, the author put forward that a sequence of solving steps can be built by using only one duffing oscillator and the method of detecting the unknown frequency signal can be achieved by changing the step size of the system. Simulation results show that compared with the conventional duffing oscillator detection method, the proposed method has improved the SNR (signal-to-noise ratio) by at least 10.6 dB. Comparing with duffing system chaotic oscillator column and double duffing system chaotic oscillator column detection method, the proposed method is most effective in detecting line spectrum of ship-radiated noise

    FINT: Field-aware INTeraction Neural Network For CTR Prediction

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    As a critical component for online advertising and marking, click-through rate (CTR) prediction has draw lots of attentions from both industry and academia field. Recently, the deep learning has become the mainstream methodological choice for CTR. Despite of sustainable efforts have been made, existing approaches still pose several challenges. On the one hand, high-order interaction between the features is under-explored. On the other hand, high-order interactions may neglect the semantic information from the low-order fields. In this paper, we proposed a novel prediction method, named FINT, that employs the Field-aware INTeraction layer which captures high-order feature interactions while retaining the low-order field information. To empirically investigate the effectiveness and robustness of the FINT, we perform extensive experiments on the three realistic databases: KDD2012, Criteo and Avazu. The obtained results demonstrate that the FINT can significantly improve the performance compared to the existing methods, without increasing the amount of computation required. Moreover, the proposed method brought about 2.72\% increase to the advertising revenue of a big online video app through A/B testing. To better promote the research in CTR field, we will release our code as well as reference implementation of those baseline models in the final version.Comment: 5 pages, Submitted to CIKM 202

    Impacts of sea-land and mountain-valley circulations on the air pollution in Beijing-Tianjin-Hebei (BTH): A case study

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    In the study, observational data analyses and the WRF-CHEM model simulations are used to investigate the role of sea-land and mountain-valley breeze circulations in a severe air pollution event occurred in Beijing-Tianjin-Hebei (BTH) during August 9-10, 2013. Both the wind observations and the model simulations have clearly indicated the evolution of the sea-land and mountain-valley breeze circulations during the event. The WRF-CHEM model generally reproduces the local meteorological circulations and also performs well in simulating temporal variations and spatial distributions of fine particulate matters (PM2.5) and ozone (O-3) concentrations compared to observations in BTH. The model results have shown that the offshore land breeze transports the pollutants formed in Shandong province to the Bohai Gulf in the morning, causing the formation of high O-3 and PM2.5 concentrations over the gulf. The onshore sea breeze not only causes the formation of a convergence zone to induce upward movement, mitigating the surface pollution to some degree, also recirculates the pollutants over the gulf to deteriorate the air quality in the coastal area. The upward valley breeze brings the pollutants in the urban area of Beijing to the mountain area in the afternoon, and the downward mountain breeze transports the pollutants back during nighttime. The intensity of the mountain-valley breeze circulation is weak compared to the land-sea breeze circulation in BTH. It is worth noting that the local circulations play an important role when the large-scale meteorological conditions are relatively weak. (C) 2017 Elsevier Ltd. All rights reserved
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