检索结果-南通市图书馆

A novel spaceborne SAR wide-swath imaging approach based on Poisson disk-like nonuniform sampling and compressive sensing

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第8期55卷 1876-1887页

作者： SUN JinPing,zhang YuXi,TIAN JiHua&WANG jun {2. of Electronic and information engineering,Beihang university,beijing 100191,china 1. school of Electronic and information {2. Beihang University Beijing 100191 China

Since the range swath width in the conventional single channel spaceborne synthetic aperture radar(SAR)is restricted by the system parameters,there is a trade-off between the azimuth resolution and the swath width in order to satisfy the Nyquist sampling *** this paper,we propose a novel spaceborne SAR wide-swath imaging scheme based on compressive sensing(CS)for the sparse *** proposed method designs a Poisson disk-like nonuniform sampling pattern in the azimuth direction,which meets the demand of wider swath by restricting the smallest time interval between any two azimuth samples,with the conventional sampling pattern preserved in the range *** a similar way to the processing procedure of spectral analysis(SPECAN)algorithm,the linear range migration correction(RMC)is realized while carrying out range compression,which can meet the demand for focusing with middle level *** reduce the computation load of CS reconstruction,we propose a novel fast reconstruction algorithm based on nonuniform fast Fourier transform(NUFFT),which greatly reduces the computation complexity from O(2. N)to O(4N log N).Experiment results validate the effectiveness of the proposed methods via the point target simulation and the Radarsat-1 raw data processing in F2.mode.

关键词： SAR wide-swath imaging compressive sensing NUFFT

Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2024年第1期33卷 303-312页

作者： Tao zhang Ying FU jun zhang school of Computer Science and Technology Beijing Institute of Technology Advanced Reasearch Institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to con{2.ct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Training Visualization Inverse problems Green products Noise reduction Pipelines Signal processing

A novel AMH variant at the prehelix loop impairs the binding to AMHR2.and causes persistent Mullerian duct syndrome

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2024年第2期26卷 222-224页

作者： Qiang du Chuang Qiu Yuan-Yuan zhang Xue-{2. Shang Xiao-Liang Liu Center of Reproductive Medicine Shengjing Hospital of China Medical UniversityShenyang 110004China Department of Orthopedics Shengjing Hospital of China Medical UniversityShenyang 110004China Department of Clinical Genetics Shengjing Hospital of China Medical UniversityShenyang 110004China Department of Urology Jinling HospitalSchool of MedicineNanjing UniversityNanjing 210012China

Dear Editor,Persistent Mullerian duct syndrome(PMDS;Online Mendelian Inheritance in Man[OMIM]:#2.1550)is a rare autosomal recessive inherent difference in sex development in males with Mullerian duct derivatives,including the uterus,fallopian tubes,and upper part of the vagina.'Approximately 88%of PMDS patients were found to have biallelic variants in the anti-Mullerian hormone(AMH;OMIM:*600957)or AMH type 2.receptor(AMHR2.OMIM:*600956)genes,and the rest were referred as idiopathic.I The serum AMH levels are usually very low or undetectable in PMDS patients with AMH gene mutations but normal or elevated in those with AMHR2.gene ***,an adult Chinese patient with PMDS carrying biallelic variants of the AMH gene was reported to have unexpectedly normal serum AMH *** refer to Supplementary information of Patient and Methods for methodologies.

关键词： elevated AMH Muller

Spotlight SAR sparse sampling and imaging method based on compressive sensing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第8期55卷 1816-1829页

作者： XU HuaPing1,YOU YaNan1,LI ChunSheng1&zhang LvQian2.1S chool of electronics and {2. engineering,Beihang university,beijing 100191,china 2. hinese Academy of engineering,beijing 100088,china 1. school of electronics and {2. engineering Beihang University Beijing 100191 China2. Chinese Academy of Engineering Beijing 100088 China

Spotlight synthetic aperture radar(SAR)emits a chirp signal and the echo bandwidth can be reduced through dechirp processing,where the A/D sampling rate decreases accordingly at the *** sensing allows the compressible signal to be reconstructed with a high probability using only a few samples by solving a linear program *** paper presents a novel signal sampling and imaging method for application to spotlight SAR based on compressive *** signal is randomly sampled after dechirp processing to form a low-dimensional sample set,and the dechirp basis is imported to reconstruct the dechirp *** pursuit(MP)is used as a reconstruction *** reconstructed signal uses polar format algorithm(PFA)for *** our novel mechanism increases the system complexity to an extent,the data storage requirements can be compressed *** simulations verify the feasibility and accuracy of spotlight SAR signal processing via compressive sensing,and the method still obtains acceptable imaging results with 10%of the original echo data.

关键词： spotlight SAR dechirp processing compressive sensing radar signal processing

Interfacial DMI in Fe/Pt thin films grown on different buffer layers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 712-718页

作者：张文君魏菲刘冰周阳康仕寿孙兵 school of Physics and Electronic information Weifang UniversityWeifang 261061China school of Physics and State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China

We study the interfacial Dzyaloshinskii-Moriya interactions(i-DMI)of Fe/Pt bilayers grown on Si substrates with MgO,SiO_(2.,or Ta each as a buffer layer on the basis of wave-vector-resolved Brillouin light scattering(BLS)*** obtained i-DMI energy values for Fe/Pt on MgO,Ta,and SiO_(2. buffer layers are 0.359,0.32.,and 0.2.4 mJ/m~2.*** large i-DMI value observed in Fe/Pt system on the MgO buffer layer can be attributed to the good interfacial quality and the Rshaba effect at the MgO/Fe ***,the MgO/Fe/Pt system,benefiting from better sample quality,exhibits a lower damping ***,layer-resolved first-principles calculations are carried out to gain a more in-depth understanding of the origin of the i-DMI in the Fe/Pt *** results indicate that in the Fe(110)/Pt(111)system,the substantial DMI energy between Fe spins at the interface is related to a significant change in spin-orbit coupling(SOC)energy in the neighboring Pt *** contrast,for the MgO(002./Fe(002.system,both the DMI and its related SOC energy are concentrated at the interfacial Fe *** investigation will provide a valuable insight into the spintronic community in exploring novel devices with chirality dependence.

关键词： Fe/Pt i-DMI BLS ferromagnetic resonance magnetic relaxation

Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1631-1642页

作者： Rong Zhao jun-e Feng Dawei zhang the school of Mathematics Shandong UniversityShandong UniversityJinan 250100China

Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor pro{2.ct technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results.

关键词： Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization synchronization

Network layered priority mapping theory

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2010年第9期53卷 1713-1726页

作者： YANG Dong*,zhang HongKe,SONG Fei&LI ShiYong National engineering Laboratory for Next Generation Internet Interconnection Devices, {2. of electronics and information engineering,beijing Jiaotong university,beijing 100044,china 1. National engineering Laboratory for Next Generation Internet Interconnection Devices School of Electronics and Information Engineering Beijing Jiaotong University Beijing 100044 China

In the early days of the Internet layered design,the information between layers did not exchange in large amount *** the rapid growth of the Internet,the emergence of many technologies such as service data partition,multi-connection and multi-path has made it possible to frequently exchange complex information between *** regard to these changes,this paper intro{2.ces "network layered priority mapping(NLPM)" for future Internet *** NLPM aims to maximize the satisfaction of the Internet *** NLPM is designed to differentiate priority of the information on different layers and integrate the information using priority *** NLPM,network services can be delivered more efficiently;network utilization such as the utilization of connection,path and channel can also be *** analysis,NS simulation and prototype implementation have proved the efficiency of NLPM.

关键词： future Internet layered priority mapping

Memristive oscillator to memristive map,energy characteristic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2024年第5期67卷 1567-1578页

作者： GUO YiTong MA jun zhang XiaoFeng HU XiKui College of Electrical and information engineering Lanzhou University of TechnologyLanzhou730050China Department of Physics Lanzhou University of TechnologyLanzhou730050China school of Science Chongqing University of Posts and TelecommunicationsChongqing400065China

Most of nonlinear oscillators composed of capacitive and inductive variables can obtain the Hamilton energy by using the Helmholtz theorem when the models are rewritten in equivalent vector *** energy functions for biophysical neurons can be obtained by applying scale transformation on the physical field energy in their equivalent neural *** dynamical systems often have exact energy functions,while some mathematical models just suggest generic Lyapunov functions,and the energy function is effective to predict mode *** this paper,a memristive oscillator is approached by two kinds of memristor-based nonlinear circuits,and the energy functions are defined to predict the dependence of oscillatory modes on energy *** absence of capacitive variable for capacitor,the physical time t and charge q are converted into dimensionless variables by using combination of resistance and inductance(L,R),e.g.,τ=t×R/*** energy function for each memristive map is proposed by applying the similar weights as energy function for the memristive *** example,energy function for the map is obtained by replacing the variables and parameters of the memristive oscillator with corresponding variables and parameters for the memristive *** memristive map prefers to keep lower average energy than the memristive oscillator,and chaos is generated in a discrete system with two *** scheme is helpful for energy definition in maps,and it provides possible guidance for verifying the reliability of maps by considering the energy characteristic.

关键词： Hamilton energy memristor Helmholtz theorem scale transformation memristive circuit

Max-Min Adaptive Ant Colony Optimization Approach to Multi-UAVs Coordinated Trajectory Replanning in Dynamic and Uncertain Environments

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic engineering 2009年第2期6卷 161-173页

作者： Hai-bin duan,Xiang-yin zhang,Jiang Wu,Guan-{2. Maschool of Automation Science and Electrical engineering,Beihang university,beijing 100191,P.R.china [a]school of Automation Science and Electrical engineering Beihang University Beijing 100191 P. R. China

Multiple Uninhabited Aerial Vehicles (multi-UAVs) coordinated trajectory replanning is one of the most complicated global optimum problems in multi-UAVs coordinated control. Based on the construction of the basic model of multi-UAVs coordinated trajectory replanning, which includes problem description, threat modeling, constraint conditions, coordinated function and coordination mechanism, a novel Max-Min adaptive Ant Colony Optimization (ACO) approach is presented in detail. In view of the characteristics of multi-UAVs coordinated trajectory replanning in dynamic and uncertain environments, the minimum and maximum pheromone trails in ACO are set to enhance the searching capability, and the point pheromone is adopted to achieve the collision avoidance between UAVs at the trajectory planner layer. Considering the simultaneous arrival and the air-space collision avoidance, an Estimated Time of Arrival (ETA) is decided first. Then the trajectory and flight velocity of each UAV are determined. Simulation experiments are performed under the complicated combating environment containing some static threats and popup threats. The results demonstrate the feasibility and the effectiveness of the proposed approach.

关键词： Multiple Uninhabited Aerial Vehicles (multi-UAVs) Ant Colony Optimization (ACO) trajectory replanning collision avoidance Estimated Time of Arrival (ETA)