检索结果-内蒙古大学图书馆

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yunhui Tang Lu Gao Ruzhi Wang Shengjun Zhang Hang Song Yuning Zhang Xia Ai Lei Xie Luting Jiao Xiaoling Zhang Jing He Jiaqi Liu Beijing University of Technology Beijing China National Key Laboratory of Science & Technology on Test Physics and Numerical Mathematics Beijing China Beijing Institute of Space Long March Vehicle Beijing China

X-ray is an important tool for characterizing materials, which is based on the idea that all crystals are composed of atoms or molecules stacking in a particular type, basically expressing as unit cell, diffracting the incident ray with a proper type. In analogue, the periodic structures which are mostly constructed artificially show special desired properties, such as the properties of grating, frequency selective surfaces, metamaterials and metasurface. In this paper, A study was done on the insight of the relation of wave interaction with periodic structures based on X-ray diffraction and control of electromagnetic waves.

关键词： Frequency selective surfaces Stacking Electromagnetic scattering Crystals X-ray diffraction Metasurfaces Computational electromagnetics

来源：评论

学校读者我要写书评

暂无评论

Cone-Shaped Space Target Inertia Characteristics Identification by Deep Learning with Compressed Dataset

TechRxiv

引用

TechRxiv 2022年

作者： Li, Mengmeng Wang, Shaoran Yang, Tian Ai, Xia Liu, Jiaqi Andriulli, Francesco P. Ding, Dazhi Department of Communication Engineering Nanjing University of Science and Technology Nanjing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China Politecnico di Torino of Turin Turin Italy

An effective method for identifying inertia characteristics of cone-shaped space target based on deep learning is proposed. The inertia ratio is determined by the time-varying scattering fields from the cone-shaped targets. The multistatic method is introduced to reduce the evaluation time of time-varying scattering fields. The micro-Doppler spectrogram (MDS) dataset is constructed by time-frequency analysis with numerical simulation method, point scattering model, and experimental tests. The compressed dataset is further achieved by truncated singular value decomposition (SVD). Finally, the micro-motion parameter identification model is constructed to identify the inertia ratio for the cone-shaped space target. The interaction loss function and the feed-forward denoising convolutional neural networks (DnCNNs) are employed to improve the identification accuracy. Parameters identification of the precession frequency, precession angle, spin frequency, and inertia ratio with both simulation and experiment datasets demonstrate the validity of the proposed method. © 2022, CC BY.

关键词： Singular value decomposition

来源：评论

学校读者我要写书评

暂无评论

An Improved DSDV Protocol based on Link Stability with Adaptive Period for Intra-cluster Routing in High-dynamic Flying UAV Networks

An Improved DSDV Protocol based on Link Stability with Adapt...

引用

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yiguo Zhang Lai Qian Xiaoqin Xue Wei Wang College of Computer Science Xi’an Polytechnic University Xi’an China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

We propose a stability-based adaptive-period DSDV intra-cluster routing protocol that automatically adjusts the routing update period by the link stability among the nodes in the cluster structure, thus reducing the network overhead of the network structure in maintaining the routing table. We describe the link stability and adaptive period implementation and test the proposed routing protocol in the cluster structure based on network simulation. The implementation results show that the proposed routing protocol has better performance than the traditional DSDV routing protocol, can improve the network throughput and reduce the routing overhead in the network, and has good adaptability in the cluster with fast changing network topology.

关键词： Costs Adaptive systems Network topology Routing Throughput Computational electromagnetics Routing protocols

来源：评论

学校读者我要写书评

暂无评论

Research on Heterogeneous Parallel Algorithms for Radar Signal Processing in OpenCL Platform

Research on Heterogeneous Parallel Algorithms for Radar Sign...

引用

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yingfei Wang Xiaoqin Xue Wei Wang Department of Computer Science Xi’an Polytechnic University Xi’an China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

An efficient radar signal processing parallel algorithm for Open Computing Language (OpenCL) is presented in this paper, which reveals a rational allocation schema of tasks between the central processing unit (CPU) and the graphics processing unit (GPU). The powerful parallel processing ability of GPU is used to replace the traditional serial processing method by the way of pipeline acceleration and algorithm parallel acceleration, and the real-time performance of the proposed algorithm is improved by the design idea of intra-module parallelism and inter-module flow processing. The algorithm is applied to CPU-GPU heterogeneous computing platform and has a good portability. The effectiveness and real-time performance of the algorithm are verified through simulation data.

关键词： Signal processing algorithms Graphics processing units Radar signal processing Real-time systems Heterogeneous networks Central Processing Unit Resource management

来源：评论

学校读者我要写书评

暂无评论

Spectral–spatial attention fusion transformer for hyperspectral image classification

Spectral–spatial attention fusion transformer for hyperspec...

引用

IET International Radar Conference (IRC 2023)

作者： Xiangyu Ji Jingpeng Gao Geng Chen Lu Gao College of Information and Communication Engineering Harbin Engineering University Harbin People's Republic of China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing People's Republic of China

ISBN: (数字)9781837240982

In view of the limited generalization and poor local feature information modeling ability of vision transformer model(ViT) in hyperspectral image classification, a Spectral-Spatial Attention Fusion Transformer (SAFT) method for hyperspectral image classification is proposed in this paper. The proposed method includes two key modules: Spectral-Spatial Feature Extraction Module (SSFE) and Multi-Head Attention Fusion Transformer Module (MAFT). The SSFE module is a lightweight network. It contains a 3D convolution block and a 2D convolution block, which can efficiently obtain local feature information. Based on the proposed attention fusion structure, the MAFT module designs an improved transformer encoder. It improves the generalization ability of the model on the premise of obtaining global information. In this paper, two datasets of HyRANK are used for experiments. The experimental results show that this method is superior to other HSI classification methods.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Intra-pulse modulation feature analysis and parameter estimation of phase and frequency multi-modulation signal

Intra-pulse modulation feature analysis and parameter estima...

引用

IET International Radar Conference (IRC 2023)

作者： Chenle Xue Zhiye Jiang Lixiang Ren Huayu Fan Quanhua Liu Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing 100081 People's Republic of China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing 100076 People's Republic of China

ISBN: (数字)9781837240982

The parameter inversion of multi-modulation waveforms has always been a key and difficult problem in the field of electronic reconnaissance. To solve this problem, a method for intra-pulse modulation feature analysis and parameter estimation of phase and frequency multi-modulation signal is proposed in this paper. Firstly, we apply square preprocessing to eliminate the binary phase coded modulation information. Then, subpulse separation and subpulse parameter estimation are achieved by using the smooth pseudo-Wigner Ville distribution (SPWVD) and wavelet transform. Moreover, histogram statistics are introduced to improve the robustness of the method. Finally, the N-order phase difference is proposed for recovering binary phase coded sequences. Frequency domain filtering and sliding window averaging are also added to further improve the applicability of the proposed method under low signal-to-noise ratio (SNR) conditions. Simulation results suggest that the method proposed in this paper can achieve accurate signal inversion and has good robustness.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Characteristic Mode Design of Dual-Band Multistate Tunable Absorber Based on Programmable Flexible Metasurface

TechRxiv

引用

TechRxiv 2022年

作者： Li, Mengmeng Ning, Zihao Ding, Dazhi Ai, Xia Liu, Jiaqi Wang, Chao-Fu The Department of Communication Engineering Nanjing University of Science and Technology Nanjing China The National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China The Department of Electrical and Computer Engineering National University of Singapore Singapore

Theory of characteristic modes (TCM) is applied to the design of a programmable flexible metasurface (PFMS) to achieve its multistate tunable microwave absorption. The designed metasurface consists of two layers. The first layer is a very thin polyimide (PI), on which unit cells consisting of two trapezoidal patches symmetrical along the central bias microstrip are printed. The second layer is grounded polyvinyl chloride (PVC) substrate to maintain the flexibility of the designed structure. The TCM is used to analyze and understand the modal behavior of the unit cell, which provides clear underlying electromagnetic (EM) physics to guide us how to load positive-intrinsic-negative (PIN) diode as a tunable resistance to achieve variable absorption states. The designed PFMS absorber have been fabricated and experimentally verified on the flat and cylindrical foams, respectively. Good agreements can be found for both planar and cylindrical metasurface structures between full-wave simulations and measurements. Less than -10 dB reflectivity is achieved from 3.6 to 10.7 GHz (99%). The mimicry of time-varying scattering cross section (SCS) is further realized through real-time coding PFMS absorber, which can be precisely tuned from -30 dB to 0 dB with a step of 1.5 dB at 5.5 GHz and 10.4 GHz, respectively. © 2022, CC BY.

关键词： Polyvinyl chlorides

来源：评论

学校读者我要写书评

暂无评论

A Radar Signal Modulation Recognition Algorithm Based on Multi-branch Fusion Difference

A Radar Signal Modulation Recognition Algorithm Based on Mul...

引用

IEEE International Conference on Electronic Information and Communication technology (ICEICT)

作者： Sisi Jiang Jingpeng Gao Zhiye Jiang Fang Ye College of Information and Communication Engineering Harbin Engineering University Haibin China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China National Key Laboratory of Underwater Acoustic Technology College of Information and Communication Engineering Harbin Engineering University Harbin China

The time-frequency images of radar modulation signals are similar at low signal-to-noise ratios, which will lead to lower recognition accuracy. This paper proposes an algorithm based on multi-branch fusion differences to identify radar modulation signals. The algorithm designs a multi-branch fusion differential module based on the attention mechanism and differential thinking, to extract time-frequency image fine-grained features and improve the Convolution Neural Network characterization ability. After that, a dual-branch differential network is proposed by combining vanilla convolution and multi-branch fusion difference module. The network can fuse global and detailed features of time-frequency images, which can achieve radar signal modulation recognition. The simulation results show that the recognition accuracy of the algorithm can reach 93.17% at 0dB. Therefore, the algorithm can obtain high recognition accuracy and has high recognition performance.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Intercept Strategy for Maneuvering Target Based on Deep Reinforcement Learning

Intercept Strategy for Maneuvering Target Based on Deep Rein...

引用

第40届中国控制会议

作者： Xu Wang Yuanli Cai Yizhong Fang Yifan Deng School of Automation Science and Engineering Xi'an Jiaotong University National Key Laboratory of Science Technology on Test Physics & Numerical Mathematics

A novel interception strategy for high-speed maneuvering target based on reinforcement learning（RL） algorithm is proposed. With reshaped reward function and observation consisting solely of relative position information and path angle, the interception policy is trained by Deep Deterministic Policy Gradient（DDPG） algorithm. The results of training and test indicate that the proposed guidance law can approximate the optimal control model of the maneuvering target interception and show the superiority over traditional method.

关键词： Exoatmospheric Interception Maneuvering Target Deep Reinforcement Learning DDPG

来源：评论

学校读者我要写书评

暂无评论

A Jamming Decision-Making Method Based on Next State Prediction SAC

A Jamming Decision-Making Method Based on Next State Predict...

引用

IEEE International Conference on Electronic Information and Communication technology (ICEICT)

作者： Geng Chen Jingpeng Gao Tianran Zhang Zhiye Jiang Chen Shen College of Information and Communication Engineering Harbin Engineering University Haibin China Beijing Institute of Electronic System Engineering Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

In light of the growing complexity of the electromagnetic environment, traditional jamming decision-making methods have become less effective due to poor generalization and inefficient jamming performance. This paper proposes a jamming decision-making method based on next state prediction SAC (Soft Actor-Critic) to address this issue. Firstly, we design the state, action, and reward elements under electronic warfare scenarios. Secondly, a next state prediction critic network is proposed to accurately estimate the value function by modeling the environment dynamics and extracting richer representational information. Finally, a negative activation ReLU is introduced to improve the utilization ratio of network parameters. Simulation results show that the proposed method achieves a 98.4% success rate at a distance of 90 km from the radar and a 70.0% success rate at 30 km. Therefore, this method exhibits good adaptability and jamming performance in the field of jamming decision-making.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：