检索结果-内蒙古大学图书馆

SSRN 2024年

作者： Chen, Yu Li, Xiang Luan, Chao Hou, Weimin Liu, Haochen Xue, Lian Zhu, Zihui Zhang, Jianqi Liu, Delian Wu, Xin Wei, Linfang Jian, Chaochao Li, Jinze Academy of Military Sciences School of Physics and Optoelectronic Engineering Xidian University Xi’an710071 China Beijing Institute of Control & Electronics Technology Beijing100038 China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China

RGB-T segmentation represents an innovative approach driven by advancements in multi-spectral detection, poised to replace traditional RGB segmentation methods. An effective cross-modality feature fusion module is essential for this technology;simultaneously, the precise segmentation of distant objects is likewise a significant challenge. Building on these two focuses, we propose an end-to-end distant object feature fusion network (DOFFNet) for RGB-T segmentation. Initially, we introduce a cross-level interaction fusion strategy (CLIF) and an inter-correlation fusion method (IFFM) in the encoder to enhance multi-scale feature expression and improve fusion accuracy. Subsequently, we propose a residual-dense pixel convolution (R-DPC) in the decoder with a trainable upsampling unit, which dynamically reconstructs information lost during encoding, particularly for distant objects whose features may vanish after pooling. Experimental results demonstrate that DOFFNet improves accuracy across five classes and effectively segments distant objects occupying 0.2-2% of total pixels, enhancing overall segmentation quality and detailed understanding of RGB-T scenes. © 2024, The Authors. All rights reserved.

关键词： Semantic Segmentation

来源：评论

学校读者我要写书评

暂无评论

Design and Simulation of a Planar Printed Slot Array Antenna

Design and Simulation of a Planar Printed Slot Array Antenna

引用

2023 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition, iWEM 2023

作者： Xiaofei, Shi Jiaxin, Shi Jiaqi, Liu Zhongyi, Fang Lei, Wang Lizhong, Song Shandong Institute of Space Electronic Technology Yantai264003 China Harbin Institute of Technology School of Electronics and Information Engineering Harbin150001 China Harbin Institute of Technology at Weihai School of Information Science and Engineering Weihai264209 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Shandong Huayu Aerospace Technology Co. Ltd Yantai264003 China

ISBN: (纸本)9798350336740

This paper designs an array antenna with a planar printed structure. The antenna element adopts a rectangular slot antenna, and the antenna element is excited by a T-shaped feeding structure. The microstrip power distribution network is used to feed the antenna radiator array with equal power. The microstrip power distribution network and slot radiator array are located on top and bottom of dielectric substrate, and the array antenna is implemented by use of the printed circuit technology. In order to improve the gain, a metal reflector ground is placed below the dielectric substrate. A planar printed slot array antenna working in X band is designed. The coaxial line is used to feed the array antenna at the bottom. The whole antenna structure is easy to feed and suitable for fabrication. The designed array antenna was numerically calculated using full wave electromagnetic simulation software. At a working frequency of 10.1GHz, the voltage standing wave ratio (VSWR) of the antenna is about 1.35, and the gain is about 21.46dB. The design of the antenna scheme can be used as a reference for the actual application of engineering. © 2023 IEEE.

关键词： Slot antennas

来源：评论

学校读者我要写书评

暂无评论

Impact of Perturbation Schemes on the Ensemble Prediction in a Coupled Lorenz Model

引用

Advances in Atmospheric sciences 2023年第3期40卷 501-513页

作者： Qian ZOU Quanjia ZHONG Jiangyu MAO Ruiqiang DING Deyu LU Jianping LI Xuan LI State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth Science University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Frontiers Science Center for Deep Ocean Multispheres and Earth System(FDOMES)/Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies Ocean University of ChinaQingdao 266100China Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China

Based on a simple coupled Lorenz model,we investigate how to assess a suitable initial perturbation scheme for ensemble forecasting in a multiscale system involving slow dynamics and fast *** initial perturbation approaches are used in the ensemble forecasting experiments:the random perturbation(RP),the bred vector(BV),the ensemble transform Kalman filter(ETKF),and the nonlinear local Lyapunov vector(NLLV)*** show that,regardless of the method used,the ensemble averages behave indistinguishably from the control forecasts during the first few time *** to different error growth in different time-scale systems,the ensemble averages perform better than the control forecast after very short lead times in a fast subsystem but after a relatively long period of time in a slow *** to the coupled dynamic processes,the addition of perturbations to fast variables or to slow variables can contribute to an improvement in the forecasting skill for fast variables and slow *** the initial perturbation approaches,the NLLVs show higher forecasting skill than the BVs or RPs *** NLLVs and ETKFs had nearly equivalent prediction skill,but NLLVs performed best by a narrow *** particular,when adding perturbations to slow variables,the independent perturbations(NLLVs and ETKFs)perform much better in ensemble *** results are simply implied in a real coupled air–sea *** the prediction of oceanic variables,using independent perturbations(NLLVs)and adding perturbations to oceanic variables are expected to result in better performance in the ensemble prediction.

关键词： ensemble prediction nonlinear local Lyapunov vector(NLLV) ensemble transform Kalman filter(ETKF) coupled air-sea models

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 2023, IRC 2023

作者： Xue, Chenle Jiang, Zhiye Ren, Lixiang Fan, Huayu Liu, Quanhua Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing100081 China Key Laboratory of Electronic and Information Technology in Satellite Navigation Beijing Institute of Technology Ministry of Education Beijing100081 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing100076 China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing314019 China Chongqing Innovation Center Beijing Institute of Technology Chongqing401120 China

ISBN: (纸本)9781839539954

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. © The Institution of Engineering & technology 2023.

关键词： Wigner-Ville distribution

来源：评论

学校读者我要写书评

暂无评论

Design of a Printed Monopole Array Antenna with the Simple Feeding Structure

Design of a Printed Monopole Array Antenna with the Simple F...

引用

2023 International Applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Xiaofei, Shi Yizhuo, Liu Jiaqi, Liu Yizhong, Fang Zhiwei, Gao Lei, Wang Lizhong, Song Shandong Institute of Space Electronic Technology Yantai China School of Electronics and Information Engineering Harbin Institute of Technology Harbin150001 China School of Information Science and Engineering Harbin Institute of Technology at Weihai Weihai264209 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China School of Information Science and Technology Shijiazhuang Tiedao University Shijiazhuang050043 China Shandong Huayu Aerospace Technology Co.Ltd Yantai264003 China

ISBN: (纸本)9781733509657

This paper introduces an array antenna by use of printed monopole antennas as element. The designed array antenna consists of two layers of dielectric substrate and a metal reflective ground. The array antenna element adopts trapezoidal printed monopole antenna, and the element is fed by coplanar waveguide (CPW). The array antenna radiator is located on the top of the upper dielectric substrate, and the feeding microstrip power divider network is located on the bottom of the lower dielectric substrate. The antenna element radiator is vertically connected to the microstrip feeding power divider network in a coaxial-like manner. The whole structure of the antenna is simple, and the feeding structure is convenient, which makes it suitable for fabrication and assembly. A printed 4x4 monopole array antenna was designed and the relevant simulated results are provided. The simulation results show that at the 10GHz, the designed array antenna has a gain of approximately 12.73 dB and a return loss of approximately -11.75 dB. The antenna scheme discussed in this paper can provide technical reference for the design of planar printed array antennas. © 2023 Applied Computational Electromagnetics Society (ACES).

关键词： Microstrip antennas

来源：评论

学校读者我要写书评

暂无评论

Tensor network Monte Carlo simulations for the two-dimensional random-bond Ising model

引用

Physical Review B 2025年第9期111卷 094201-094201页

作者： Tao Chen Erdong Guo Wanzhou Zhang Pan Zhang Youjin Deng Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics University of Science and Technology of China Hefei 230026 China Hefei National Laboratory University of Science and Technology of China Hefei 230088 China CAS Key Laboratory for Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China College of Physics Taiyuan University of Technology Shanxi 030024 China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study UCAS Hangzhou 310024 China

Disordered lattice spin systems are crucial in both theoretical and applied physics. However, understanding their properties poses significant challenges to Monte Carlo simulations. In this work, we investigate the two-dimensional random-bond Ising model using the recently proposed tensor network Monte Carlo (TNMC) method. This method generates biased samples from conditional probabilities computed via tensor network contractions and corrects the bias using the Metropolis scheme. Consequently, the proposals provided by tensor networks function as block updates for Monte Carlo simulations. Through extensive numerical experiments, we demonstrate that TNMC simulations can be performed on lattices as large as 1024×1024 spins with moderate computational resources, a substantial increase from the previous maximum size of 64×64 in Markov-chain Monte Carlo. Notably, we observe an almost complete absence of critical slowing down, enabling the efficient collection of unbiased samples and averaging over a large number of random realizations of bond disorders. We successfully pinpoint the multicritical point along the Nishimori line with significant precision and accurately determined the bulk and surface critical exponents. Our findings suggest that TNMC is a highly efficient algorithm for exploring disordered and frustrated systems in two dimensions.

关键词： Tensors

来源：评论

学校读者我要写书评

暂无评论

Intelligent Assignment Strategy for Multi-Target Adversarial Interception

Intelligent Assignment Strategy for Multi-Target Adversarial...

引用

2022 Chinese Automation Congress, CAC 2022

作者： Yu, Yang Fang, Yizhong Wu, Han Han, Tuo Hu, Qinglei Beihang University School of Automation Science and Electrical Engineering Beijing100191 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Beihang University School of Aeronautic Science and Engineering Beijing100191 China Hangzhou310023 China

ISBN: (纸本)9781665465335

The multi-missile confront multi-target is a classic target allocation issue in the combat scenario of multiple missiles intercepting multiple maneuvering targets. Traditional algorithms lack environmental assessment model, train quality, and indicator function in the adversarial environment. To this end, this paper aims to propose an intelligent assignment strategy which contains indicator function and evaluation model. Then, an indicator function and an evaluation model considering the miss distance, threat situation, and the number of specified interception targets are introduced into the reinforcement learning algorithm. The local and global reward functions are introduced to improve the training convergence and efficiency in the multi-missile multi-target confrontation scenario. Finally, simulation results are designed to check on advantage of intelligent allocation strategy. © 2022 IEEE.

关键词： Reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Perturbation Estimated Incremental Guidance for Exo-Atmospheric Interception

Perturbation Estimated Incremental Guidance for Exo-Atmosphe...

引用

2022 Chinese Automation Congress, CAC 2022

作者： Lu, Yuting Liu, Peng Han, Tuo Hu, Qinglei Beihang University School of Automation Science and Electrical Engineering Beijing100191 China Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China Beihang University School of Aeronautic Science and Engineering Beijing100191 China Hangzhou310023 China

ISBN: (纸本)9781665465335

In order to meet the requirement of accurate intercept against the increased target maneuverability and external disturbance, a second-order inertial delay based incremental guidance law (IDIASMG) is proposed for an exo-atmospheric interceptor. Specifically, a three-dimensional guidance model is transformed into an incremental version. As a guidance design benchmark, a conventional sliding mode guidance law (SMG) is presented, and a sliding mode incremental guidance law (ISMG) is designed with gain adaptation. Moreover, a second-order inertial delay filter is utilized to estimate and compensate guidance perturbation including the target maneuver, system uncertainty, and external disturbance. Theoretical analysis shows that the incremental guidance requires smaller gains to ensure smaller system residual than the conventional SMG. Extensive numerical simulations validate the effectiveness and robustness of IDIASMG. © 2022 IEEE.

关键词： Uncertainty analysis

来源：评论

学校读者我要写书评

暂无评论

1-bit Coding Metasurface for Wideband RCS Reduction

1-bit Coding Metasurface for Wideband RCS Reduction

引用

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yinfang Xu Jiaqi Liu Lu Gao Xia Ai Zhongjie Zhang Huan Liang National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing Institute of Space Long March Vehicle Beijing China

This paper achieve efficient RCS reduction over a wide frequency range by exploiting the reflection properties of the coding metasurface. The metasurface consists of “0” cells and “1” cells, and the reflection phase difference is close to 180° over a wide frequency range. By designing the spatial random coding arrangement of “0” units and “1” units, the electromagnetic waves incident on the metasurface form diffuse reflection, so as to achieve the purpose of broadband RCS reduction. The simulation results show that when the incident wave is irradiated vertically, the metasurface can basically achieve a RCS reduction of more than 10dB in a wide frequency band of 10-20.5GHz compared to a metal plate of the same size. In the case of oblique incidence, the RCS reduction still has a good effect, which is basically the same as the curve at normal incidence, and has the characteristics of wide-angle incidence RCS reduction. The reduced bandwidth of the broadband RCS of the coding metasurface is basically consistent with the 10 dB polarization bandwidth of the cell structure. The design of the metasurface is simple and efficient, so it has great application potential in stealth new technologies and new materials.

关键词： Electric potential Simulation Electromagnetic scattering Metals Metasurfaces Computational electromagnetics Reflection

来源：评论

学校读者我要写书评

暂无评论

A New One-Dimensional Photonic Crystals for Infrared Emission Modulation

A New One-Dimensional Photonic Crystals for Infrared Emissio...

引用

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yuning Zhang Shengjun Zhang Hang Song Yichun Cui Jiaqi Liu Lihong Ai National Key Laboratory of Science & Technology on Test Physics and Numerical Mathematics Beijing China Capital Aerospace Machinery Corporation Limited Beijing China

With the wide application of infrared detection in the military field, the problem of how to reduce the probability of military targets being detected and identified has become urgent. In this paper, one-dimensional photonic crystals with wide incidence angle range are analyzed and simulated. The reflectance and transmittance properties of different structures are discussed with application in modulation of infrared emission.

关键词： Reflectivity Simulation Modulation Photonic crystals Germanium Computational electromagnetics Stability analysis

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：