Ionospheric irregularities associated with Equatorial plasma bubbles (EPB) can significantly impact navigation and communication systems. Therefore, their occurrences need to be studied and predicted. To solve the pre...
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ISBN:
(数字)9798350381559
ISBN:
(纸本)9798350381566
Ionospheric irregularities associated with Equatorial plasma bubbles (EPB) can significantly impact navigation and communication systems. Therefore, their occurrences need to be studied and predicted. To solve the prediction problem, it is necessary to identify types of spatiotemporal characteristics as reference points for the predictive model. This work employs unsupervised machine learning algorithms to identify types of ionospheric irregularities due to EPB using the rate of total electron content index (ROTI) keograms. Two machine learning methods: two models, the Gaussian mixture model (GMM), and k-means, are considered. Comparative analysis is performed, and the optimal number of clusters is estimated using one classical, k-means and one additional - repeatability score, introduced in this work metric. The optimal GMM model successfully classifies three types of irregularity patterns offering valuable insights for the development of an effective EPB prediction model and enhancing our understanding of ionospheric behavior.
To address the serious threat that marine oil spills pose to the ecological environment, satellite remote sensing technology for monitoring these spills is especially important. Optical satellite remote sensing, with ...
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ISBN:
(数字)9798350379228
ISBN:
(纸本)9798350390780
To address the serious threat that marine oil spills pose to the ecological environment, satellite remote sensing technology for monitoring these spills is especially important. Optical satellite remote sensing, with its benefits of high spatial and temporal resolution, high spectral resolution, and autonomous operation, can effectively track and monitor marine oil spill incidents. However, the acquisition of optical satellite data is highly susceptible to climate conditions, making it difficult to obtain sufficient data for efficient information extraction. Therefore, this article proposes a bottleneck attention generative adversarial network (BAGAN) that can accurately extract oil spill areas from visible remote sensing data. The addition of data preprocessing and bottleneck attention module (BAM) in the model has improved the accuracy of oil spill segmentation. Through the optical remote sensing data of GF-1 satellite in the Bohai Bay from 2022 to 2023, the average accuracy reached 89.11%, verifying that this model is superior to other models in semantic segmentation.
In this paper, a continuous head motion recognition method of millimeter wave radar is studied. Firstly, a combination of standard convolution and depthwise separable convolution is used to extract features, which red...
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ISBN:
(数字)9798331542887
ISBN:
(纸本)9798331542894
In this paper, a continuous head motion recognition method of millimeter wave radar is studied. Firstly, a combination of standard convolution and depthwise separable convolution is used to extract features, which reduces the number of parameters and the size of the model while ensuring the accuracy. Then the Coordinate Attention mechanism is combined to filter the features, so that the network pays more attention to the important features. The feature dimension is reduced by using max pooling instead of full connection layer, and the parameter number and computation cost are reduced. The LSTM network is then used to train the time series data. Finally, the proposed method is verified by the measured data, and its effectiveness is proved.
The advancement of autonomous driving technology has driven a surge of applications in urban environments, where the precision of the registration of keypoint-based radar point clouds plays a crucial role in determini...
The advancement of autonomous driving technology has driven a surge of applications in urban environments, where the precision of the registration of keypoint-based radar point clouds plays a crucial role in determining the overall performance of these applications. However, numerous inaccurate keypoints would be detected in the presence of multipath, beam spread, and noise, leading to the reduction of registration accuracy of the radar point cloud. To deal with this problem, we propose an improved keypoint detection method, where a novel candidate keypoint selection strategy and a threshold selection strategy are designed. The results of experiments based on a public radar dataset demonstrate that the proposed method can effectively reduce the number of inaccurate keypoints. Moreover, it achieves high precision on radar point cloud registration compared to the state-of-the-art method.
Associating radar measurements with vision measurements is essential for radar-vision fusion. Most radar-vision association methods rely on Euclidean distance. However, these methods have overlooked measurement errors...
Associating radar measurements with vision measurements is essential for radar-vision fusion. Most radar-vision association methods rely on Euclidean distance. However, these methods have overlooked measurement errors, leading to a significant amount of erroneous associations. To address the limitations of existing methods, we propose an association method based on weighted Euclidean distance between radar measurements and vision measurements. This paper analyzes the measurement errors of radar and vision and uses this analysis as the basis for calculating weighted Euclidean distance, to make weighted Euclidean distance sensitive to measurement errors and reduce the occurrence of association mistakes caused by such inaccuracies. The obtained weighted Euclidean distance is then used as a cost matrix to perform association using the Hungarian algorithm. The proposed method is validated through simulations, and the experiments demonstrate that our approach achieves higher accuracy.
This paper constructs a detection network that combines convolutional neural network and Transformer in parallel to address the challenges of multi-scale target detection in remote sensing images. The network utilizes...
This paper constructs a detection network that combines convolutional neural network and Transformer in parallel to address the challenges of multi-scale target detection in remote sensing images. The network utilizes global and local information interaction to further improve the effectiveness of multi-scale object detection tasks. Additionally, the network introduces both top-down and bottom-up pathways to fuse multi-scale information, and employs coordinate attention mechanism to perform feature selection. The proposed network is compared with some existing networks on the LEVIR remote sensing image dataset, and the results show that the proposed network achieves higher average detection accuracy in terms of multi-scale target detection, particularly for small objects.
This paper presents a wideband variable gain amplifier (VGA) based on capacitance neutralization technique for high-speed communications and high-resolution radar systems. The negative capacitance path proposed in thi...
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With the increasing demand for precision in fault diagnosis of gearboxes in complex systems, diagnostic methods based solely on vibration signal characteristics have shown limitations. Therefore, multimodal informatio...
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ISBN:
(数字)9798350354010
ISBN:
(纸本)9798350354027
With the increasing demand for precision in fault diagnosis of gearboxes in complex systems, diagnostic methods based solely on vibration signal characteristics have shown limitations. Therefore, multimodal information fusion technology has become a new trend in the field of gearbox fault diagnosis. This article innovatively proposes a multimodal diagnostic method that combines vibration signals with thermal images, aiming to use thermal imaging technology to intuitively capture the thermal changes during gearbox operation and integrate vibration signals to comprehensively reflect fault characteristics. By introducing Convolutional Neural Networks (CNN) for feature depth extraction, this method effectively improves the parsing ability of fault information, thereby enhancing the accuracy and reliability of fault diagnosis. Experimental data confirms that compared to diagnostic methods using a single signal source, the method proposed in this paper performs well in fault detection of helical gearboxes, significantly improving diagnostic accuracy and precision.
Hybrid neural network models are effective in analyzing time-series data by combining the strengths of neural networks and differential equation *** most studies have focused on linear hybrid models,few have examined ...
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Hybrid neural network models are effective in analyzing time-series data by combining the strengths of neural networks and differential equation *** most studies have focused on linear hybrid models,few have examined nonlinear *** work explores the potential of a hybrid nonlinear epidemic neural network in predicting the correct infection function of an epidemic *** design a novel loss function by combining bifurcation theory and mean-squared error loss to ensure the trainability of the hybrid ***,we identify unique existence conditions that support ordinary differential equations for estimating the correct infection ***,numerical experiments using the Runge-Kutta method confirm our proposed model's soundness both on our synthetic data and the real COVID-19 data.
The incorporation of Internet of Things (IoT) cloud computing solutions with smart grids signifies a significant advancement in energy management. Traditional methods, though beneficial, often lack scalability and rea...
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