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A novel synthetic aperture radar scattering model for sea surface with breaking waves

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Acta Oceanologica Sinica 2022年第4期41卷 138-145页

作者： Xiaochen Wang Yuxin Hu Bing Han Wei Tian Chunhua Zhang Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Technology in Geo-spatial Information Processing and Application System Chinese Academy of SciencesBeijing 100190China The box51111 Beijing 100190China

In this study a novel synthetic aperture radar(SAR)scattering model for sea surface with breaking waves is proposed.Compared with existing models,the proposed model considers an empirical relationship between wind speed and wave breaking scattering to present the contribution of wave breaking.Moreover,the scattering weight factor p,and wave breaking rate q,are performed to present the contribution of the quasi-specular scattering term,Bragg scattering term,and wave breaking scattering term to the total scattering from the sea surface.To explore the modeling accuracy of sea-surface scattering,a simulated normalized radar cross-section(NRCS)and measured NRCS are compared.The proposed model generated the simulated NRCS and a matching GF-3 dataset was used for the measured NRCS.It was revealed that the performance of the VV polarization of our model was much better than that of HH polarization,with a correlation of 0.91,bias of-0.14 dB,root mean square error(RMSE)of 1.26 dB,and scattering index(SI)of-0.11.In addition,the novel model is explored and compared with the geophysical model of CMODs and satellite-measured NRCS from GF-3 SAR wave mode imagery.For an incidence angle 40°–41°,the relationship between the NRCS and wind speed,relative wind direction is proposed.As with the SAR-measured NRCS,the performance of VV polarization was much better than HH polarization,with a correlation of 0.99,bias of-0.25 dB,RMSE of 0.64 dB,and SI of-0.04.

关键词： synthetic aperture radar scattering model sea surface wave breaking

First assessment of Noise-Equivalent Sigma-Zero in GF3-02 TOPSAR mode with sea surface wind speed retrieval

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Acta Oceanologica Sinica 2023年第10期42卷 84-96页

作者： Junxin Yang Lihua Zhong Xinzhe Yuan Xiaochen Wang Bing Han Yuxin Hu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Technology in Geo-Spatial Information Processing and Application Systems Chinese Academy of SciencesBeijing 100190China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China National Satellite Ocean Application Service Beijing 100081China

Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment monitoring.Given the weak scattering characteristics of the ocean,the system thermal noise superimposed on SAR images has significant interference,especially in cross-polarization channels.Noise-Equivalent Sigma-Zero(NESZ)is a measure of the sensitivity of the radar to areas of low backscatter.The NESZ is defined to be the scattering cross-section coefficient of an area which contributes a mean level in the image equal to the signal-independent additive noise level.For TOPSAR,NESZ exhibits the shape of the SAR scanning gain curve in the azimuth and the shape of the antenna pattern in the range.Therefore,the accurate measurement of NESZ plays a vital role in the application of spaceborne SAR sea surface cross-polarization data.This paper proposes a theoretical calculation method for the NESZ curve in GF3-02 TOPSAR mode based on SAR noise inner calibration data and the imaging algorithm.A method for correcting the error existing in the theoretical curve of NESZ is also proposed according to the relationship between sea surface backscattering and wind speed and the same characteristics of target scattering in the overlapping area of adjacent sub-swaths.According to assessment with wide-swath TOPSAR cross-polarization data,the GF3-02 TOPSAR mode has a very low thermal noise level,which is better than−33 dB at the edge of each beam,and controlled below−38 dB at the center of the beam.The two-dimensional reference curves of the NESZ of each beam are provided to the GF3-02 TOPSAR users.After discussing the relationship between normalized radar cross section(NRCS)and wind speed,we provide a formula for NRCS related to wind speed and radar incidence angle.Compared with the NRCS derived from this formula and the NESZ-subtracted NRCS of SAR images,the bias is−0.0048 dB,the Root Mean Square Error is 1.671 dB and th

关键词： GF3-02 TOPSAR Noise-Equivalent Sigma-Zero(NESZ) cross-polarization normalized radar cross section(NRCS) sea surface wind

Modulatory effects of transcutaneous auricular vagus nerve stimulation (taVNS) on attentional processes

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General Psychiatry 2023年第6期36卷 512-522页

作者： yuxin Chen Haoyu Yang Faguang Wang Xuejing Lu Li hu CAS Key Laboratory of Mental Health Institute of PsychologyChinese Academy of SciencesBeijingChina Department of Psychology Universityof ChineseAcademy of SciencesBeijingChina School of Intelligent Manufacturing Wenzhou PolytechnicWenzhouZhejiangChina

Background The modulatory effect of transcutaneous auricular vagus nerve stimulation(taVNS)on attention has varied in previous studies.This inconsistency might be attributed to the combined influence of the modulation effect on the different attentional functions,including alerting,orienting and executive control.Aims We aimed to preliminarily examine the modulatory effectsoftaVNS on differentattentionalfunctions.Methods Fifty-nine healthy participants were recruited and were randomly assigned to taVNS(receiving taVNS for 20 minutes)or control(receiving taVNS for 30 seconds)groups.All participants underwent a dot-probe task before and after the taVNS/control intervention.Their behavioural performance and electroencephalographic signals during pre-and post-tests were recorded,and different observed variables were extracted and analysed to characterise different attentional systems.Results We observed that active taVNS applied at the left ear significantly improved the overall behavioural performance,that is,shorter reaction time(RT)and lower intra-individual reaction time variability(lIRTV)for right-hand responses when compared with the control condition.In addition,active taVNS resulted in larger P3 and movement-related cortical potential(MRCP)amplitudes associated with right-hand reactions than the control condition.Active taVNS also decreased the difference between the pre-and post-tests in the power spectral density of spontaneous high-αband oscillations at C4 electrode.Importantly,parallel mediation models for right-hand responses showed that the change of P3 amplitude mediated the effects of taVNS on RT and lIRTV.In contrast,the change of MRCP amplitude suppressed the effect of taVNS on the lIRTV.Conclusions Our results provided behavioural and brain evidence supporting the effects of taVNS on different attentional systems,and their interaction further shaped behavioural performance,suggesting a promising role of taVNS in cognitive enhancement.

关键词： stimulation vagus behaviour

A novel adaptive heuristic dynamic programming-based algorithm for aircraft confrontation games

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Fundamental Research 2021年第6期1卷 792-799页

作者： Yi Mao Zhijie Chen Yi Yang Yuxin Hu State Key Laboratory of Air Traffic Management System and Technology Nanjing 210007China

Intelligent confrontation has become a vital technology for future air combats.Confrontation games between a penetrating aircraft and an intercepting aircraft are essential for modern air combats.In addition,the perfor-mance indexes of both the interceptor and penetrator must be considered.Traditional methods only solve one side’s guidance problem without considering the intelligence of the opponent.In this paper,an adaptive heuristic dynamic programming-based algorithm is proposed for aircraft confrontation games.This algorithm constructs a heuristic dynamic programming model for both confrontation aircraft and then updates the critical and ac-tion network parameters using the dynamic confrontation state information.Numerical simulations indicate that the proposed algorithm can optimize the guidance law for both the interceptor and penetrator and is therefore superior to traditional proportional navigation methods.

关键词： Aircraft confrontation Optimal control Neural network Adaptive heuristic dynamic programming Flight simulation

Arabidopsis SMALL ORGAN_4, a homolog of yeast NOP_(53), regulates cell proliferation rate during organ growth

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Journal of Integrative Plant Biology 2015年第10期57卷 810-818页

作者： Xiao-Ran Zhang Zhixiang Qin Xiao Zhang Yuxin Hu Key Laboratory of Plant Molecular Physiology Institute of Botany the Chinese Academy of Sciences University of Chinese Academy of Sciences National Center for Plant Gene Research

Cel proliferation is a fundamental event essential for plant organogenesis and contributes greatly to the final organ size. Although the control of cel proliferation in plants has been extensively studied, how the plant sets the cel number required for a single organ is largely elusive. Here, we describe the Arabidopsis SMALL ORGAN 4 (SMO4) that functions in the regulation of cell proliferation rate and thus final organ size. The smo4 mutant exhibits a reduced size of organs due to the decreased cell number, and further analysis reveals that such phenotype results from a retardation of the cell cycle progression during organ development. SMO4 encodes a homolog of NUCLEOLAR PROTEIN 53 (NOP53) in Saccharomy-ces cerevisiae and is expressed primarily in tissues undergoing cel proliferation. Nevertheless, further complementation tests show that SMO4 could not rescue the lethal defect of NOP53 mutant of S. cerevisiae. These results define SMO4 as an important regulator of cell proliferation during organ growth and suggest that SMO4 might have been evolutionarily divergent from NOP53.

关键词： Arabidopsis cell proliferation NOP53 organ size SMO4

Pattern Matching of Industrial Alarm Floods Using Word Embedding and Dynamic Time Warping

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IEEE/CAA Journal of Automatica Sinica 2023年第4期10卷 1096-1098页

作者： Wenkai hu Xiangxiang Zhang Jiandong Wang Guang Yang yuxin Cai School of Automation China University of GeosciencesWuhan 430074Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex SystemsWuhan 430074 Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of EducationWuhan 430074China College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values that represent alarms and also reflect the relationships between alarm occurrences.Then,similarities between numerically encoded alarm flood sequences are calculated by DTW and groups of similar floods are identified via clustering.The effectiveness of the proposed method is demonstrated by a case study with alarm&event data obtained from a public industrial simulation model.

关键词： Word Alarm DTW

Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3)as an anode

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Magnetic Resonance Letters 2024年第2期4卷 40-45页

作者： yuxin Liao Fushan Geng Ming Shen Bingwen hu Shanghai Key Laboratory of Magnetic Resonance State Key Laboratory of Precision SpectroscopySchool of Physics and Electronic ScienceEast China Normal UniversityShanghai200241China

In-situ XRD,31P NMR and 23Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3)at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3)to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

关键词： Na_(3)V_(2)(PO_(4))_(3) Anode Low voltage NMR Sodium ion battery

Indocyanine green assembled free oxygen-nanobubbles towards enhanced near-infrared induced photodynamic therapy

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Nano Research 2022年第5期15卷 4285-4293页

作者： Li Yang Bin huang Shiqi hu Yuan An Jingyi Sheng Yan Li yuxin Wang Ning Gu State Key Laboratory of Bioelectronics Jiangsu Key Laboratory for Biomaterials and DevicesSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China College of Life Sciences and Chemistry Jiangsu Second Normal UniversityNanjing 210013China Nanjing Stomatology Hospital Nanjing 210008China

Photodynamic therapy(PDT)has shown a promising capability for cancer treatment with minimal side effects.Indocyanine green(ICG),the only clinically approved near-infrared(NIR)fluorophore,has been used as a photosensitizer for PDT in clinical application.However,the main obstacle of directly utilizing ICG in the clinic lies in its low singlet oxygen(1O_(2))quantum yield(QY)and instability in aqueous solution.To improve the PDT efficacy of ICG,free ICG molecules were assembled with free oxygen nanobubbles(NBs-O_(2))to fabricate ICG-NBs-O_(2) by hydrophilic-hydrophobe interactions on the gas-liquid interface.Interestingly,1O2 QY of ICG-NBs-O_(2) solution was significantly increased to 1.6%,which was estimated to be 8 times as high as that of free ICG solution.Meanwhile,ICG-NBs-O_(2) exhibited better aqueous solution stability compared with free ICG.Furthermore,through establishing tumor models in nude mice,the therapeutic efficacy of ICG-NBs-O_(2) was also assessed in the PDT treatment of oral cancer.The tumor volume in ICG-NBs-O_(2) treated group on day 14 decreased to 0.56 of the initial tumor size on day 1,while the tumor volume in free ICG treated group increased to 2.4 times.The results demonstrated that ICG-NBs-O_(2) showed excellent tumor ablation in vivo.Therefore,this facile method provided an effective strategy for enhanced PDT treatment of ICG and showed great potential in clinical application.

关键词： free oxygen-nanobubbles aqueous solution stability singlet oxygen quantum yield photodynamic therapy indocyanine green

Learning Dual-Domain Calibration and Distance-Driven Correlation Filter:A Probabilistic Perspective for UAV Tracking

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Computers, Materials & Continua 2023年第12期77卷 3741-3764页

作者： Taiyu Yan yuxin Cao Guoxia Xu Xiaoran Zhao hu Zhu Lizhen Deng Jiangsu Province Key Lab on Image Processing and Image Communication Nanjing University of Posts and TelecommunicationsNanjingChina School of Computer Science Qufu Normal UniversityQufuChina National Engineering Research Center of Communication and Network Technology Nanjing University of Posts and TelecommunicationsNanjingChina

Unmanned Aerial Vehicle(UAV)tracking has been possible because of the growth of intelligent information technology in smart cities,making it simple to gather data at any time by dynamically monitoring events,people,the environment,and other aspects in the city.The traditional filter creates a model to address the boundary effect and time filter degradation issues in UAV tracking operations.But these methods ignore the loss of data integrity terms since they are overly dependent on numerous explicit previous regularization terms.In light of the aforementioned issues,this work suggests a dual-domain Jensen-Shannon divergence correlation filter(DJSCF)model address the probability-based distance measuring issue in the event of filter degradation.The two-domain weighting matrix and JS divergence constraint are combined to lessen the impact of sample imbalance and distortion.Two new tracking models that are based on the perspectives of the actual probability filter distribution and observation probability filter distribution are proposed to translate the statistical distance in the online tracking model into response fitting.The model is roughly transformed into a linear equality constraint issue in the iterative solution,which is then solved by the alternate direction multiplier method(ADMM).The usefulness and superiority of the suggested strategy have been shown by a vast number of experimental findings.

关键词： Dual-domain weighting distance measure correlation filter ADMM